CN113196895A

CN113196895A - Electronic component mounting board and electronic apparatus

Info

Publication number: CN113196895A
Application number: CN201980083377.9A
Authority: CN
Inventors: 松戸和规; 安东健次; 早坂努; 松尾玲季
Original assignee: Toyo Ink SC Holdings Co Ltd; Toyochem Co Ltd
Current assignee: Toyochem Co Ltd; Artience Co Ltd
Priority date: 2018-12-18
Filing date: 2019-12-17
Publication date: 2021-07-30
Anticipated expiration: 2039-12-17
Also published as: CN113196895B; KR20210094094A; WO2020129985A1; TW202038696A; KR102400969B1

Abstract

An electronic component mounting substrate (51) according to an embodiment of the present invention includes: a substrate (20); an electronic component (30) mounted on at least one surface of the substrate (20); and an electromagnetic wave shielding member (1) that covers the substrate (20) from the upper surface of the electronic component (30), and that covers the side surface of the stepped portion formed by the mounting of the electronic component (30) and at least a portion of the substrate (20). The electromagnetic wave shielding member (1) has an electromagnetic wave shielding layer (5) containing a binder resin and a conductive filler, and the surface layer of the electromagnetic wave shielding member (1) is formed according to the following formula JISB 0601: 2001, the kurtosis is 1-8.

Description

Electronic component mounting board and electronic apparatus

Technical Field

The present invention relates to an electronic component mounting board having an electromagnetic wave shielding member. The present invention also relates to an electromagnetic wave shielding laminate suitable for forming an electromagnetic wave shielding member of the electronic component mounting substrate, and an electronic apparatus having the electronic component mounting substrate mounted thereon.

Background

An electronic component mounted with an Integrated Circuit (IC) chip or the like is generally provided with an electromagnetic wave shielding structure in order to prevent malfunction caused by a magnetic field or an electric wave from the outside. For example, a method of coating a substrate having electronic components with a conductive adhesive film containing an isotropic conductive adhesive and a anisotropic conductive adhesive is disclosed (patent document 1). Further, there have been disclosed a method of coating a substrate on which an electronic component is mounted with an electromagnetic wave shielding film including a conductive adhesive layer and a base material layer having a specific storage elastic modulus (patent document 2), and a method of coating a substrate on which an electronic component is mounted with an electromagnetic wave shielding member including a layer containing scale-like particles exhibiting isotropic conductivity and having a specific tensile strain at break (patent document 3).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2015/186624

Patent document 2: japanese patent laid-open No. 2014-one 57041

Patent document 3: international publication No. 2018/147355

Disclosure of Invention

Problems to be solved by the invention

For example, an electronic component mounting substrate is manufactured by coating a substrate on which an electronic component is mounted with an electromagnetic wave shielding member by the following method. First, as shown in fig. 18, an electromagnetic wave shielding laminate 104, which is a laminate of an electromagnetic wave shielding member 102 and a mold-releasable cushioning member 103, is placed on the top surface of a plurality of electronic components 130 mounted on a substrate 120. Next, as shown in fig. 19, the electromagnetic wave shielding laminate 104 is thermocompression bonded, and the electronic component 130 and a part of the substrate 120 are covered with the electromagnetic wave shielding member 101. Thereafter, as shown in fig. 20, the releasable cushioning member 103 is peeled off, and then, as shown in fig. 21, a step of singulating the substrate 120 into product units is performed. The singulation step is carried out, for example, by: the electromagnetic wave shielding member 101 is brought into contact with the cutting table 141, and the substrate 120 and the electromagnetic wave shielding member 101 are cut from the substrate 120 side by the cutting tool 142 at a position facing the groove 125 as the gap of the electronic component 130 while maintaining the contact state.

With recent stringent requirements for higher performance of electronic components, a technique for improving the performance of the electromagnetic wave shielding member 101 of the electronic component mounting substrate to a higher quality is required.

The present invention has been made in view of the above-mentioned background, and an object thereof is to provide an electronic component mounting board and an electronic apparatus having an electromagnetic wave shielding member with high reliability.

Means for solving the problems

The present inventors have made extensive studies and, as a result, have found that the following embodiments can solve the problems of the present invention, and have completed the present invention.

[1]: an electronic component mounting board includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member that covers the substrate from the upper surface of the electronic component, and covers a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate; the electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler, and the surface layer of the electromagnetic wave shielding member is a layer having a thickness according to Japanese Industrial Standards (JIS) B0601: 2001, the kurtosis (kurtosis) is 1-8.

[2]: the electronic component mounting board according to [1], wherein the electromagnetic wave shielding member has a surface layer whose thickness is in accordance with JISB 0601: 2001, the root mean square height Rq is 0.3 to 1.7 μm.

[3]: the electronic component mounting substrate according to any one of [1] and [2], wherein the conductive filler contains at least one of a dendritic conductive filler and a needle-like conductive filler.

[4]: an electronic component mounting board includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member that covers the substrate from the upper surface of the electronic component, and covers a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate;

the electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler, and has a compression elastic modulus of 1GPa to 10 GPa.

[5]: the electronic component mounting substrate according to [4], wherein a water contact angle of a surface layer of the electromagnetic wave shielding member is 70 ° to 110 °.

[6]: the electronic component mounting substrate according to [4] or [5], wherein the electromagnetic wave shielding member on the electronic component exhibits a transverse cut residual ratio of 23/25 or more in a tape adhesion test after a pressure cooker test according to JIS K5600 of the electromagnetic wave shielding member.

[7]: the electronic component mounting board according to any one of [4] to [6], wherein a surface layer of the electromagnetic wave shielding member is formed in accordance with a standard of JIS B0601: 2001, the measured kurtosis is 1-8.

[8]: the electronic component mounting substrate according to any one of [4] to [7], wherein a root mean square height of a surface of the electromagnetic wave shielding member is in a range of 0.4 μm to 1.6 μm.

[9]: according to [4]]～[8]The electronic component mounting substrate according to any one of the above, wherein the electromagnetic wave shielding member has a Martens hardness (Martens hardness) of 50N/mm²～312N/mm²。

[10]: the electronic component mounting substrate according to any one of [4] to [9], wherein the adhesive resin is obtained by thermocompression bonding an adhesive resin precursor containing a thermosetting resin and a curable compound having a functional group capable of crosslinking with a reactive functional group of the thermosetting resin.

[11]: the electronic component mounting substrate according to any one of [4] to [10], wherein the electromagnetic wave shielding member has a film thickness of 10 μm to 200 μm.

[12]: an electronic component mounting board includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member that covers the substrate from the upper surface of the electronic component, and covers a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate; the electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler, and the root-mean-square height Rq of the surface layer of the electromagnetic wave shielding member is 0.05 [ mu ] m or more and less than 0.3 [ mu ] m.

[13]: the electronic component mounting substrate according to [12], wherein a root mean square slope Rdq of a surface layer of the electromagnetic wave shielding member is 0.05 to 0.4.

[14]: the electronic component mounting substrate according to any one of [12] and [13], wherein a water contact angle of a surface layer of the electromagnetic wave shielding member is 90 ° to 130 °.

[15]: the electronic component mounting substrate according to any one of [12] to [14], wherein the conductive filler contains at least one of a dendritic or needle-like conductive filler and a scaly conductive filler.

[16]: an electronic device on which the electronic component mounting board according to any one of [1] to [15] is mounted.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an excellent effect is obtained that an electronic component mounting substrate and an electronic apparatus having an electromagnetic wave shielding member with high reliability can be provided.

Drawings

Fig. 1 is a schematic perspective view showing an example of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

FIG. 2 is a sectional view of the cut-away section II-II in FIG. 1.

Fig. 3 is a schematic cross-sectional view showing another example of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 4 is a schematic cross-sectional view showing an example of the electromagnetic wave shielding laminate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 5 is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 6 is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 7 is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 8 is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a1, embodiment B1, and embodiment C1.

Fig. 9 is a schematic explanatory view for explaining a variation factor of the kurtosis of the surface layer of the electromagnetic wave shielding member.

Fig. 10 is a schematic explanatory view for explaining a variation factor of the kurtosis of the surface layer of the electromagnetic wave shielding member.

Fig. 11 is a schematic cross-sectional view showing an example of the electromagnetic wave shielding laminate according to embodiment a2, embodiment B2, and embodiment C2.

Fig. 12 is a schematic cross-sectional view showing an example of the electromagnetic wave shielding laminate according to embodiment a3, embodiment B3, and embodiment C3.

Fig. 13 is a schematic cross-sectional view showing an example of the electromagnetic wave shielding laminate according to embodiment a4, embodiment B4, and embodiment C4.

Fig. 14A is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a4, embodiment B4, and embodiment C4.

Fig. 14B is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a4, embodiment B4, and embodiment C4.

Fig. 14C is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a4, embodiment B4, and embodiment C4.

Fig. 15A is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a5, embodiment B5, and embodiment C5.

Fig. 15B is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a5, embodiment B5, and embodiment C5.

Fig. 15C is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to embodiment a5, embodiment B5, and embodiment C5.

Fig. 16A is a schematic cross-sectional view showing an example of a manufacturing process of an electronic component mounting substrate according to a modification.

Fig. 16B is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to the modification.

Fig. 16C is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to the modification.

Fig. 16D is a schematic cross-sectional view showing an example of a manufacturing process of the electronic component mounting substrate according to the modification.

Fig. 17 is a schematic cross-sectional view showing an example of the electronic component mounting substrate of the present embodiment.

Fig. 18 is a schematic cross-sectional view for explaining a step of coating an electromagnetic wave shielding member on an electronic component or the like.

Fig. 19 is a schematic cross-sectional view for explaining a step of coating an electromagnetic wave shielding member on an electronic component or the like.

Fig. 20 is a schematic cross-sectional view for explaining a step of coating an electromagnetic wave shielding member on an electronic component or the like.

Fig. 21 is a schematic cross-sectional view for explaining a step of coating an electromagnetic wave shielding member on an electronic component or the like.

Fig. 22 is an optical microscope photograph of a side surface of the electronic component mounting board of embodiment B3.

Fig. 23 is an optical microscope photograph of a side surface of the electronic component mounting substrate of reference example B1.

Fig. 24 is an explanatory view of the method of evaluating the electronic component mounting substrate of embodiment C.

Detailed Description

An example of an embodiment to which the present invention is applied will be described below. Note that the numerical values specifically defined in the present specification are values obtained by the methods disclosed in the embodiments or examples. In addition, the numerical values "a to B" specifically defined in the present specification mean ranges satisfying the numerical value a and a value larger than the numerical value a, and the numerical value B and a value smaller than the numerical value B. The sheet in the present specification includes not only the sheet defined in JIS but also a film. For the sake of clarity, the following description and drawings are simplified as appropriate. Each component appearing in the present specification may be used alone or in combination of two or more, unless otherwise noted. For convenience of explanation, the same component parts are denoted by the same reference numerals in different embodiments.

As the electronic component mounting substrate of the present invention, the electronic component mounting substrates of embodiments a to C are disclosed.

[ [ embodiment A ] ]

The electronic component mounting substrate according to embodiment a includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member covering the substrate from the upper surface of the electronic component, and covering a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate. The electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler. Further, the surface layer of the electromagnetic wave shielding member is formed in accordance with JISB 0601: 2001, the measured kurtosis is 1-8.

According to the conventional technique, a residue as shown in (i) of fig. 20 may adhere to the electromagnetic wave shielding member 101 of the electronic component mounting substrate. The residue is a residue derived from the releasable cushioning member 103 which is a constituent member of the electromagnetic wave shielding laminate 104 for forming the electromagnetic wave shielding member 101. In the step of peeling the releasable buffer member 103 after thermocompression bonding the electromagnetic wave shielding laminate 104, the residue is generated by the anchor effect of the groove 125 formed in the gap between the electronic components 130. The residue is a fragment of the releasable cushioning member 103. The chips become a factor remaining as residues even after the singulation step. Such residue on the electromagnetic wave shielding member 101 may not only cause poor appearance but also cause a decrease in reliability of the electromagnetic wave shielding property of the electronic device, and may become an obstacle when packaging the electronic device on a circuit board.

As a method for avoiding the above problem, a method of increasing the width of the gap between the electronic components 130 or decreasing the height of the electronic components 130 in order to reduce the anchor effect of the groove 125 may be considered. However, the above method has a problem that the shape of the electronic component 130 is limited and cannot be applied to the electronic component 130 having complicated unevenness. Further, if the gap between the electronic components 130 mounted on the substrate 120 can be reduced, the yield of the electronic components 130 obtained from one substrate 120 can be increased, and the manufacturing efficiency can be improved. In addition, in order to prevent a decrease in reliability due to scratches of the electromagnetic wave shielding member 101 during transportation or packaging of the electronic component 130, the electromagnetic wave shielding member 101 is required to have high abrasion resistance.

According to the electronic component mounting substrate of embodiment a, it is possible to provide an electronic component mounting substrate having an electromagnetic wave shielding member with high design flexibility, suppressed adhesion of residue, and excellent scratch resistance and high reliability. Therefore, the present invention is particularly suitable for use in an electronic component mounting substrate for which a degree of freedom in design is intended to be improved, or an electronic component mounting substrate which is likely to be scratched.

[ [ embodiment B ] ]

The electronic component mounting substrate according to embodiment B includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member covering the substrate from the upper surface of the electronic component, and covering a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate. The electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler, and has a press-fitting elastic modulus of 1GPa to 10 GPa.

According to the prior art, there are the following problems: in the singulation step in the manufacturing step of the electronic component mounting substrate, burrs, which are the curl-up of the electromagnetic wave shielding member 101 with the cut surface of the electromagnetic wave shielding member 101 as the base point, are likely to occur (see the partially enlarged view (ii) of fig. 21). The factors of the burrs of the electromagnetic wave shielding member 101 are high-pressure water washing at the time of cutting in the singulation step, and the like. In addition, the electronic component mounting substrate after the production may have poor adhesion between the electromagnetic wave shielding member 101 and the substrate 120 or the like under high humidity and high temperature conditions. The generation of burrs in the electromagnetic wave shielding member 101 and the decrease in adhesion cause a decrease in reliability of the electromagnetic wave shielding property of the electronic device, and may become an obstacle when packaging the electronic device on a circuit board.

According to the electronic component mounting board of embodiment B, it is possible to provide an electronic component mounting board having an electromagnetic wave shielding member which can suppress the occurrence of burrs, has excellent Pressure Cooker Test (PCT) performance, and has high reliability and high reliability. Therefore, the method is particularly suitable for strict applications under conditions such as high-pressure water lines in the singulation step, and applications of electronic component mounting substrates requiring durability under high-humidity and high-heat conditions.

[ [ embodiment C ] ]

The electronic component mounting substrate according to embodiment C includes: a substrate; an electronic component mounted on at least one surface of the substrate; and an electromagnetic wave shielding member covering the substrate from the upper surface of the electronic component, and covering a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate. The electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler, and the root mean square height Rq of the surface layer of the electromagnetic wave shielding member is set to be 0.05 [ mu ] m or more and less than 0.3 [ mu ] m.

According to the prior art, there are the following situations: in the singulation step, the electromagnetic wave shielding member 101 is brought into contact with the cutting table 141 (see fig. 21) via a dicing tape (not shown), and the substrate 120 and the electromagnetic wave shielding member 101 are cut from the substrate 120 side by the cutting tool 142 at positions facing the grooves 125 as gaps of the electronic component 130 while maintaining the contact state. In this case, the electronic component mounting substrate is manufactured after singulation through a step of peeling the dicing tape from the electromagnetic wave shielding member 101. However, when the dicing tape is peeled off after singulation, the electromagnetic wave shielding member 101 may be lifted. In addition, a part of the electromagnetic wave shielding member may be peeled off. When the cooling-heating cycle test was performed (50 ℃ C. to 125 ℃ C.), cracks may occur in the electromagnetic wave shielding member.

Such floating and cracking of the electromagnetic wave shielding member 101 may cause various problems as well as appearance defects. For example, when the electromagnetic wave shielding member 101 and the housing are connected to the ground by a conductive adhesive or a conductive adhesive, the adhesion force or the connection resistance is deteriorated, and the reliability of the electromagnetic wave shielding property of the electronic device is lowered, which may be an obstacle when the electronic device is mounted on a circuit board. Further, there is a problem in reliability over time.

According to the electronic component mounting substrate of embodiment C, it is possible to provide an electronic component mounting substrate having an electromagnetic shielding member with excellent covering properties, high reliability, and high reliability. Therefore, the present invention is particularly suitable for applications including a step of bringing the electromagnetic wave shielding member into contact with the dicing table by the dicing tape, or applications requiring passage of a cooling-heating cycle test, for example, applications requiring performance to withstand severe temperature changes such as electronic component mounting boards mounted on automobiles.

[ [ embodiment A ] ]

A specific example of the electronic component mounting board of embodiment a will be described below.

[ embodiment A1]

< electronic component mounting substrate >

Fig. 1 is a schematic perspective view showing an example of the electronic component mounting board according to embodiment a1, and fig. 2 is a sectional view of the II-II cut portion in fig. 1. The electronic component mounting substrate 51 includes a substrate 20, an electronic component 30, an electromagnetic wave shielding member 1, and the like.

The substrate 20 may be selected as desired as long as it can carry the electronic component 30 and can withstand the thermocompression bonding step described later. Examples thereof include: a work board, a package module board, a printed wiring board, or a build-up board formed by a build-up method or the like, on the surface or inside of which a conductive pattern including copper foil or the like is formed. In addition, a film or a sheet-like flexible substrate may be used. The conductive pattern is, for example, an electrode/wiring pattern (not shown) for electrically connecting to the electronic component 30, and a ground pattern 22 for electrically connecting to the electromagnetic wave shielding member 1. The substrate 20 may be provided with an electrode/wiring pattern, a through hole (not shown), and the like as desired. The substrate 20 may be a flexible substrate as well as a rigid substrate.

In the example of fig. 1, the electronic components 30 are arranged in a5 × 4 array on the substrate 20. The electromagnetic wave shielding member 1 is provided so as to cover the exposed surfaces of the substrate 20 and the electronic component 30. That is, the electromagnetic wave shielding member 1 is coated so as to follow the irregularities formed by the electronic component 30. The electromagnetic wave shielding member 1 shields unnecessary radiation generated from signal wiring and the like built in the electronic component 30 and/or the substrate 20, and prevents malfunction caused by a magnetic field or an electric wave from the outside.

The number, arrangement, shape, and type of the electronic components 30 are arbitrary. Instead of arranging the electronic components 30 in an array, the electronic components 30 may be arranged at arbitrary positions. When the electronic component mounting substrate 51 is singulated into unit modules, as shown in fig. 2, the half-cut grooves 25 may be provided so as to divide the unit modules in the thickness direction of the substrate from the upper surface of the substrate. The electronic component mounting substrate according to embodiment a1 includes both a substrate before being singulated into unit modules and a substrate after being singulated into unit modules. That is, the electronic component mounting substrate 51 on which a plurality of unit modules (electronic components 30) are mounted as shown in fig. 1 and 2 includes an electronic component mounting substrate 52 which is singulated into unit modules as shown in fig. 3. Needless to say, the present invention also includes an electronic component mounting substrate in which one electronic component 30 is mounted on the substrate 20 and covered with the electromagnetic wave shielding member without a singulation step. That is, the electronic component mounting board according to embodiment a1 has the following configuration: at least one electronic component is mounted on the substrate, and the electromagnetic wave shielding member covers at least a part of the stepped portion formed by the mounting of the electronic component.

The electronic component 30 includes all components in which electronic elements such as a semiconductor integrated circuit are integrally covered with an insulator. For example, a semiconductor chip 31 (see fig. 3) on which an integrated circuit (not shown) is formed is molded with a sealing material (molding resin 32). The substrate 20 and the semiconductor chip 31 are electrically connected to the wiring or the electrode 21 formed on the substrate 20 via the contact region therebetween, or via a bonding wire 33, a solder ball (not shown), or the like. Examples of the electronic component include an inductor, a thermistor, a capacitor, and a resistor, in addition to the semiconductor chip.

The electronic component 30 and the substrate 20 according to embodiment a1 can be widely applied to known forms. In the example of fig. 3, the semiconductor chip 31 is connected to the solder balls 24 on the back surface of the substrate 20 via the internal through holes 23. In addition, a ground pattern 22 for electrically connecting the electromagnetic wave shielding member 1 is formed in the substrate 20. As in embodiment a4 described later, a plurality of electronic components 30 may be mounted on the electronic component mounting substrate that has been singulated or the electronic component mounting substrate that has not been singulated (see fig. 14C). One or more electronic components and the like may be mounted in the electronic component 30.

< electromagnetic wave shielding member >

The electromagnetic wave shielding member 1 is obtained by: after the electromagnetic wave shielding laminate is placed on the top surface of the electronic component 30 mounted on the substrate 20, the electronic component 30 and the substrate 20 are covered by thermal compression. The electromagnetic wave shielding member 1 covers the substrate 20 from the upper surface of the electronic component 30, and covers the side surface of the step portion formed by mounting the electronic component 30 and at least a part of the substrate 20. In order to sufficiently exhibit the shielding effect, the electromagnetic wave shielding member 1 is preferably connected to the ground pattern 22 exposed on the side surface or the upper surface of the substrate 20 and/or a ground pattern (not shown) such as a connection wiring of the electronic component 30.

The electromagnetic wave shielding member 1 can be formed using a laminate for electromagnetic wave shielding. Fig. 4 is a schematic cross-sectional view of an electromagnetic wave shielding laminate. The electromagnetic wave shielding laminate 4 of embodiment a1 includes an electromagnetic wave shielding member 2 and a mold-releasable cushioning member 3. In embodiment a1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 and the substrate 20 by thermocompression bonding to form the electromagnetic wave shielding layer 5. In embodiment a1, the electromagnetic wave-shielding layer 5 functions as the electromagnetic wave-shielding member 1.

The electromagnetic wave shielding member 2 may be formed of a laminate of other layers, such as a laminate of two or more conductive adhesive layers as in embodiment a2 described later, a laminate of a conductive adhesive layer and a hard coat layer as in embodiment A3, or a laminate of an insulating adhesive layer and a conductive adhesive layer as in embodiment a 4. The electromagnetic wave shielding member 1 obtained by thermocompression bonding the electromagnetic wave shielding member 2 includes a laminate of two or more electromagnetic wave shielding layers in embodiment a2, a laminate of an electromagnetic wave shielding layer and a hard coat layer in embodiment A3, and a laminate of an insulating coating layer and an electromagnetic wave shielding layer in embodiment a 4. In this manner, the electromagnetic wave shielding member may include a laminate of the electromagnetic wave shielding layer and another layer.

The electromagnetic wave shielding layer 5 contains a binder resin and a conductive filler. The conductive filler in the electromagnetic wave-shielding layer 5 is continuously contacted and exhibits conductivity. From the viewpoint of improving the electromagnetic wave shielding property, the sheet resistance value of the electromagnetic wave shielding layer 5 is preferably 1 Ω/□ or less.

The electromagnetic wave shielding member 1 has a surface layer formed by laminating a plurality of layers in accordance with JISB 0601: 2001, the measured kurtosis is 1-8. The kurtosis is an index representing a roughness curve of surface unevenness represented by the mathematical formula (1), and represents flatness and kurtosis of height distribution.

[ mathematical formula 1]

Here, L is a reference length. In addition, Rq is a root mean square height, and is represented by the following equation (2) with z (x) being a height change of the surface along one axis (x axis).

[ mathematical formula 2]

The kurtosis represents an average value of the fourth power of z (x) in a reference length dimensionless by the fourth power of the root mean square height Rq. When the kurtosis is 3, the distribution of the peaks indicating the convex portions (or concave portions) approaches the normal distribution. As the kurtosis becomes larger by 3, the number of sharp projections (or recesses) indicating a steep peak with respect to the reference height Rq increases, and as the kurtosis becomes smaller by 3, the number of sharp projections (or recesses) indicating a steep peak decreases.

The manufacturing method will be described later, but when the electromagnetic wave shielding laminate 4 is thermally press-bonded to a substrate on which the electronic component 30 is mounted and the releasable buffer member 3 is peeled from the electromagnetic wave shielding member 1, the releasable buffer member 3 of the half-cut groove 25 is peeled off while being rubbed substantially perpendicularly. Since the releasable cushioning member 3 is easily broken by the anchor effect, a technique for suppressing the breakage is required. As a result of extensive studies, the present inventors have found that it is important to control the shape of the contact interface of the electromagnetic wave shielding member 1, and as the shape, the range of the kurtosis is suitable.

By setting the kurtosis to 8 or less, the mold-releasable cushioning member 3 filled in the half-cut groove 25 of the electronic component 30 can be satisfactorily peeled from the electromagnetic wave shielding member 1. The reason for this is considered to be: the degree of peak of the surface shape of the electromagnetic wave shielding member 1 becomes an appropriate degree of peak, and the releasable cushioning member 3 and the electromagnetic wave shielding member 1 are easily peeled off. On the other hand, by setting the kurtosis of the surface layer of the electromagnetic wave shielding member 1 to 1 or more, the steel wool resistance can be improved. As a result, the scratch resistance is improved, and an electronic component mounting board having high reliability is provided. The electromagnetic wave shielding member preferably has a kurtosis value in the range of 1.5 to 6.5, and more preferably in the range of 2 to 4.

The root-mean-square height of the surface of the electromagnetic wave shielding member 1 is preferably in the range of 0.4 to 1.6 μm, more preferably 0.5 to 1.5 μm, and still more preferably 0.7 to 1.2 μm. In the present specification, the kurtosis and the root mean square height are values obtained by the methods described in the examples described later.

The degree of peakedness of the surface of the electromagnetic wave shielding member 1 can be adjusted by the manufacturing process of the electromagnetic wave shielding member 2 in the electromagnetic wave shielding laminate 4. The type of each component in the composition for forming the electromagnetic wave shielding member before thermocompression bonding of the electromagnetic wave shielding member 1 and the amount of the component to be blended can be adjusted. Details will be described later. Further, the present inventors have made extensive studies and have confirmed that by blending an amount of the conductive filler capable of functioning as an electromagnetic wave shielding layer, the value of kurtosis does not substantially change before and after reflow soldering, or the amount of change is small even if it changes.

< method for manufacturing electronic component mounting substrate >

An example of a method for manufacturing the electronic component mounting board according to embodiment a1 will be described below with reference to fig. 5 to 8. However, the method for manufacturing the electronic component mounting board of the present invention is not limited to the following manufacturing method.

The method for manufacturing the electronic component mounting board 51 according to embodiment a1 includes: [a] mounting the electronic component 30 on the substrate; [b] a step of placing the electromagnetic wave shielding laminate 4 on the substrate 20 on which the electronic component 30 is mounted; [c] a step of bonding the electromagnetic wave shielding member 1 by thermocompression bonding so as to follow at least a part of the exposed surface of the substrate and the side surface of the step portion formed by mounting the electronic component 30; [d] a step of peeling off the releasable cushioning member 3; and [ e ] a step of singulating the electronic component mounting substrate 51. Hereinafter, each step will be described.

[a] Mounting an electronic component on a substrate:

first, the electronic component 30 is mounted on the substrate 20. For example, a semiconductor chip (not shown) is mounted on the substrate 20, the substrate 20 on which the semiconductor chip is formed is molded with a sealing resin, and the molding resin and the substrate 20 are half-cut by dicing or the like so as to reach the inside of the substrate 20 from above between the electronic components 30. The electronic components 30 may be arranged in an array on the substrate 20 that has been half-cut in advance. Through these steps, a substrate on which the electronic component 30 is mounted as shown in fig. 5, for example, can be obtained. In the example of fig. 5, the electronic component 30 is an integrated body formed by molding a semiconductor chip, and refers to all electronic components protected by an insulator. The half-cut may be formed to reach the surface of the substrate 20, in addition to the inside of the substrate 20. In addition, the entire substrate 20 may be cut at this stage. In this case, the substrate 20 is preferably placed on a base with an adhesive tape so as not to be displaced. The material of the sealing resin used in the press molding is not particularly limited, but a thermosetting resin is generally used. The method for forming the sealing resin is not particularly limited, and examples thereof include: printing, laminating, transfer molding, compressing, casting, and the like. The molding is optional, and the method of mounting the electronic component 30 may be changed arbitrarily.

[b] A step of placing an electromagnetic wave shielding laminate on a substrate:

next, an electromagnetic wave shielding laminate 4 (see fig. 4) is prepared, which is melted by thermocompression bonding and covers the substrate 20 on which the electronic component 30 is mounted. The electromagnetic wave shielding laminate 4 is placed on the top surface of the electronic component 30 so that the conductive adhesive layer 6 of the electromagnetic wave shielding laminate 4 is on the electronic component 30 side. In this case, the electromagnetic wave shielding laminate 4 may be temporarily adhered to a part or the entire surface of the electronic component 30. The temporary adhesion refers to a state where the conductive adhesive layer 6 is fixed to the adherend in the B-stage, and the temporary bonding is performed so as to be in contact with at least a part of the upper surface of the electronic component 30. As the peeling force, in a 90 DEG peeling test, the peeling force with respect to Kapton (Kapton)200 is preferably about 1N/cm to 5N/cm. Examples of the temporary adhesion method include: the electromagnetic wave shielding laminate 4 is placed on the substrate 20 on which the electronic component 30 is mounted, and the entire surface or the end portions are lightly thermally pressed by a heat source such as an iron to temporarily adhere the laminate. A plurality of electromagnetic wave shielding laminates 4 may be used in each region of the substrate 20 according to the manufacturing equipment, the size of the substrate 20, and the like. The electromagnetic wave shielding laminate 4 may be used for each electronic component 30. From the viewpoint of simplification of the manufacturing process, it is preferable to use one electromagnetic wave shielding laminate 4 for the entire plurality of electronic components 30 mounted on the substrate 20.

[c] A step of forming an electromagnetic wave shielding member:

then, the electromagnetic wave shielding laminate 4 is sandwiched between a pair of pressing substrates 40 on the substrate 20 on which the electronic component 30 is mounted, and thermocompression bonded (see fig. 6). In the electromagnetic wave shielding laminate 4, the conductive adhesive layer 6 and the releasable cushioning member 3 are melted by heat, extend along the half-cut groove provided in the production substrate by pressing, and cover the electronic component 30 and the substrate 20. The conductive adhesive layer 6 is bonded to the electronic component 30 or the substrate 20, and functions as the electromagnetic wave shielding layer 5 by thermocompression bonding. In embodiment a1, since the electromagnetic wave shielding member 1 includes a single electromagnetic wave shielding layer 5, the electromagnetic wave shielding layer 5 as the electromagnetic wave shielding member 1 is formed by thermocompression bonding the conductive adhesive layer 6. After the thermocompression bonding, a heating treatment may be separately performed for the purpose of promoting thermosetting or the like.

When the electromagnetic wave shielding laminate 4 is heated and pressed, a thermal softening member, a cushion paper, or the like may be used as needed between the electromagnetic wave shielding laminate 4 and the pressing substrate 40.

The temperature and pressure in the thermocompression bonding step can be arbitrarily set independently within a range in which the covering property of the conductive adhesive layer 6 can be secured, depending on the heat resistance, durability, manufacturing equipment, or requirements of the electronic component 30. The pressure range is not limited, but is preferably about 0.1MPa to 5.0MPa, and more preferably 0.5MPa to 2.0 MPa. By releasing the pressing substrate 40, a production substrate as shown in fig. 7 can be obtained. In this way, the top and side surfaces of the electronic component and the exposed surface of the substrate are covered with the electromagnetic wave shielding member 1.

The heating temperature in the thermocompression bonding step is preferably 100 ℃ or higher, more preferably 110 ℃ or higher, and still more preferably 120 ℃ or higher. The upper limit depends on the heat resistance of the electronic component 30, but is preferably 220 ℃, more preferably 200 ℃, and still more preferably 180 ℃.

The thermocompression bonding time can be set in accordance with the heat resistance of the electronic part 30, the adhesive resin used for the electromagnetic wave shielding member 1, the production process, and the like. When a thermosetting resin is used as the binder resin precursor, the range of about 1 minute to 2 hours is suitable. The thermocompression bonding time is more preferably about 1 minute to 1 hour. The thermosetting resin is cured by the thermocompression bonding. However, the thermosetting resin may be partially cured or substantially cured before thermocompression bonding as long as it is flowable.

The thickness of the conductive adhesive layer 6 is set to be such that the electromagnetic wave shielding layer 5 can be formed so as to cover the top and side surfaces of the electronic component 30 and the exposed surface of the substrate 20. The fluidity of the binder resin precursor used, and the distance and size between the electronic components 30 may vary, but is preferably about 10 to 200 μm. This makes it possible to improve the coating property with respect to the sealing resin and effectively exhibit the electromagnetic wave shielding property.

The following materials can be used for the releasable cushioning member 3: softening promotes coating of the conductive adhesive layer 6, has a function of coating the top and side surfaces of the electronic component 30 and the exposed surface of the substrate 20, and is excellent in mold release property in the peeling step. As the upper layer of the releasable cushioning member 3, a thermo-softening member that functions as a cushioning material may be used as needed. In the example of embodiment a1, the electromagnetic wave shielding member 1 is coated with the ground pattern 22 formed in the substrate 20, and the electromagnetic wave shielding member 1 is electrically connected (see fig. 7).

The conductive adhesive layer 6 contains a binder resin precursor and a conductive filler. As the binder resin precursor, there can be exemplified: thermoplastic resin, self-crosslinking resin, various reactive resins, and a mixture of a curable resin and a crosslinking agent. These may also be used in combination. When a thermoplastic resin is exclusively used as the binder resin precursor, the binder resin precursor and the binder resin can be said to be substantially the same in the sense of not having a crosslinked structure.

[d] A step of peeling off the releasable cushioning member:

the releasable cushioning member 3 covering the upper layer of the electromagnetic wave shielding member 1 is peeled off. Thus, an electronic component mounting board 51 (see fig. 1 and 2) having the electromagnetic wave shielding member 1 covering the electronic component 30 is obtained. For example, the releasable cushioning member 3 may be peeled off from the end portion by a manual force, or may be peeled off from the electromagnetic wave shielding member 1 by attracting the outer surface of the releasable cushioning member 3. In terms of improving the yield by automation, the peeling by suction is preferable.

[e] The step of performing singulation:

the electronic component mounting board 51 is cut in the X direction and the Y direction at positions corresponding to individual product areas using a cutting tool such as a dicing blade (see fig. 2). Through these steps, a singulated electronic component mounting substrate 51 in which the electronic component 30 is covered with the electromagnetic wave shielding member 1 and the ground pattern 22 formed on the substrate 20 is electrically connected to the electromagnetic wave shielding member 1 can be obtained. The method of dicing is not particularly limited as long as singulation can be performed. The dicing may be performed from the substrate 20 side or the electromagnetic wave shielding laminate 4 side.

Since the releasable buffer member 3 is peeled off at an angle of, for example, 90 ° with respect to the substrate surface in the step (d), a large friction is generated at the contact interface between the releasable buffer member 3 of the half-cut groove 25 and the electromagnetic wave shielding member 1 on the side surface of the half-cut groove 25. Therefore, it is technically difficult to cleanly peel off the releasable cushioning member 3 from the electromagnetic wave shielding member 1, and as described with reference to fig. 20, the releasable cushioning member 3 may be broken in the half-cut groove 25 and a residue may remain. Even after the singulation step, the residue remains depending on the position, and thus reliability is degraded.

According to embodiment a1, the step of forming the electromagnetic wave shielding member of the electronic component mounting substrate in which the electromagnetic wave shielding laminate is thermally press-bonded to the electronic component mounting substrate can improve the releasability of the electromagnetic wave shielding member from the releasable buffer member by setting the kurtosis of the electromagnetic wave shielding member 1 to 8. In addition, a part of the electromagnetic wave shielding member is peeled off together with the mold-releasable cushion member, and a phenomenon that a part of the electromagnetic wave shielding member is damaged can be effectively suppressed. Therefore, the electronic component mounting substrate with high reliability can be provided. In addition, the degree of freedom in designing the height of the electronic components mounted on the substrate or the width of the gap between the electronic components can be increased.

< laminate for electromagnetic wave shielding >

As described with reference to fig. 4, the electromagnetic wave shielding laminate according to embodiment a1 includes two layers, namely, an electromagnetic wave shielding member 2 and a mold-releasable cushioning member 3. In embodiment a1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 or the substrate 20 through a thermocompression bonding step, and functions as the electromagnetic wave shielding layer 5.

(conductive adhesive layer)

The conductive adhesive layer 6 is a layer formed of a resin composition containing a binder resin precursor and a conductive filler. The binder resin precursor contains at least a thermo-softening resin. Examples of the thermosoftening resin include thermoplastic resins, thermosetting resins, and actinic ray-curable resins. The thermosetting resin and the actinic ray-curable resin generally have a reactive functional group. When a thermosetting resin is used, a curing compound or a thermosetting auxiliary may be used in combination. When an actinic ray-curable resin is used, a photopolymerization initiator, a sensitizer, or the like may be used in combination. In terms of simplicity of the production process, a thermosetting type that cures during thermocompression bonding is preferable.

Further, a self-crosslinkable resin or a plurality of resins crosslinked with each other may be used. In addition to these resins, thermoplastic resins may be mixed. The compounding ingredients such as the resin and the curable compound may be used independently or in combination.

Further, a B-stage (semi-cured state) may be obtained by forming partial cross-linking at the stage of the conductive adhesive layer 6. For example, the thermosetting resin may be in a state of being half-cured by reacting with a part of the curable compound.

Suitable examples of the heat-softening resin include: a polyurethane resin, a polycarbonate resin, a styrene elastomer resin, a phenoxy resin, a polyurethaneurea resin, a polyimide resin, a polyamide resin, a polycarbonate imide resin, a polyamideimide resin, an epoxy ester resin, an acrylic resin, a polyester resin, polystyrene, a polyesteramide resin, and a polyetherester resin. The thermosetting resin used under severe conditions in reflow soldering preferably contains at least one of an epoxy resin, an epoxy ester resin, a urethane urea resin, and a polyamide.

Among these resins, polyurethane resins, polycarbonate resins, styrene elastomer resins, phenoxy resins, polyamide resins, and polyimide resins are preferable. Further, a resin having a polycarbonate skeleton represented by the general formula (1) in the resin is preferable.

-R-O-CO-O- … general formula (1)

Wherein R is a divalent organic group.

The heat-softening resins may be used singly or in combination of two or more kinds at an arbitrary ratio.

Examples of the resin having a polycarbonate skeleton include, in addition to polycarbonate resins: a polyurethane resin having a polycarbonate skeleton, a polyamide resin, and a polyimide resin. For example, polycarbonate imide resins have a polyimide skeleton, and thus can improve heat resistance, insulation properties, and chemical resistance. On the other hand, the polycarbonate skeleton effectively improves flexibility and adhesion.

As the polycarbonate urethane resin, a polycarbonate polyol based on one or more diols such as 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 1, 4-cyclohexanedimethanol, 1, 9-nonanediol, and 2-methyl-1, 8-octanediol can be used as the polyol component.

The thermo-softening resin may have a plurality of functional groups available for a crosslinking reaction by heating as a thermosetting resin. Examples of functional groups include: hydroxyl group, phenolic hydroxyl group, carboxyl group, amino group, epoxy group, oxetanyl group, oxazoline group, oxazinyl group, aziridinyl group, thiol group, isocyanate group, blocked isocyanate group, silanol group, and the like.

The curable compound has a functional group capable of crosslinking with a reactive functional group of the thermosetting resin. The hardening compound is preferably an epoxy compound, a compound having an acid anhydride group, an isocyanate compound, a polycarbodiimide compound, an amine compound such as an aziridine compound, a dicyanodiamide compound or an aromatic diamine compound, a phenol compound such as a phenol novolac resin, an organic metal compound, or the like. The curable compound may also be a resin. In this case, the thermosetting resin and the curable compound are classified into those having a larger content and those having a smaller content.

The curable compound is contained preferably in an amount of 1 to 70 parts by mass, more preferably 3 to 65 parts by mass, and still more preferably 3 to 60 parts by mass, based on 100 parts by mass of the thermosetting resin. The curable compound may be used singly or in combination.

Suitable examples of the thermoplastic resin include: polyester, acrylic resin, polyether, urethane resin, styrene elastomer, polycarbonate, butadiene rubber, polyamide, ester amide resin, polyisoprene, and cellulose. Examples of the adhesion-imparting resin include: rosin-based resins, terpene-based resins, alicyclic petroleum resins, aromatic petroleum resins, and the like. In addition, conductive polymers may be used. Examples of the conductive polymer include: polyethylene dioxythiophene, polyacetylene, polypyrrole, polythiophene and polyaniline. Suitable examples of the thermoplastic resin include: polyester, acrylic resin, polyether, urethane resin, styrene elastomer, polycarbonate, butadiene rubber, polyamide, ester amide resin, polyisoprene, and cellulose.

Examples of the conductive filler include: metal fillers, conductive ceramic particles, and mixtures of these. Examples of the metal filler include: metal powder such as gold, silver, copper, and nickel, alloy powder such as solder, and core-shell type particles such as silver-plated copper powder, gold-plated copper powder, silver-plated nickel powder, and gold-plated nickel powder. From the viewpoint of obtaining excellent conductive characteristics, a conductive filler containing silver is preferable. From the viewpoint of cost, silver-plated copper powder using silver-coated copper powder is particularly preferable.

The silver content in the silver-plated copper is preferably 3 to 20 mass%, more preferably 8 to 17 mass%, and still more preferably 10 to 15 mass% of the total of 100 mass% of silver and copper. In the case of the core-shell type particles, the coating rate of the coating layer with respect to the core portion is preferably 60% or more, more preferably 70% or more, and still more preferably 80% or more on average. The core may be a nonmetal, but from the viewpoint of conductivity, a conductive material is preferable, and metal particles are more preferable.

As the conductive filler, an electromagnetic wave absorbing filler may also be used. Examples thereof include: iron, an iron alloy such as Fe-Ni alloy, Fe-Co alloy, Fe-Cr alloy, Fe-Si alloy, Fe-Al alloy, Fe-Cr-Si alloy, Fe-Cr-Al alloy, or Fe-Si-Al alloy, a ferrite system such as Mg-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, or Ni-Zn ferrite, and a carbon filler. The carbon filler may be exemplified by: acetylene black, ketjen black, furnace black, carbon fiber, particles comprising carbon nanotubes, graphene particles, graphite particles, and carbon nanoplatelets.

Examples of the shape of the conductive filler used in the conductive adhesive layer include scale-like particles, dendritic particles, needle-like particles, plate-like particles, grape-like particles, fibrous particles, and spherical particles, but from the viewpoint of adjusting a desired value of the kurtosis, a conductive filler containing needle-like particles and/or dendritic particles is preferable. Here, the needle-like shape means a shape having a major diameter three times or more as large as a minor diameter, and includes a spindle shape, a cylindrical shape, and the like in addition to the needle-like shape. The term "dendritic" means a shape in which a plurality of branches extend two-dimensionally or three-dimensionally from a rod-like main axis when observed by an electron microscope (500 to 20,000 times). In a dendrimer, the branches may also be bent or extend further from the branch.

Further, by containing the flaky particles as the conductive filler, an electromagnetic wave shielding member having excellent covering properties can be provided. Here, the scale-like shape also includes a flake shape and a plate shape. The conductive filler may be in the form of an ellipse, a circle, or a slit around the fine particle, as long as the entire particle is in the form of a scale.

The conductive fillers may be used alone or in combination. In the case of using the conductive filler in combination, from the viewpoint of obtaining a desired kurtosis and providing an electromagnetic wave shielding member with high reliability, a combination of scaly particles and dendritic particles, a combination of scaly particles and acicular particles, and a combination of scaly particles, dendritic particles, and acicular particles are preferable. Particularly preferred are combinations of scale-like particles and needle-like particles.

The content of the conductive filler in the solid content (100 mass%) of the thermally softening resin composition layer is preferably 40 to 85 mass%, and more preferably 50 to 80 mass%.

The needle-like particles and/or dendritic particles are preferably 50 mass% or less with respect to 100 mass% of the conductive filler in the conductive adhesive layer. More preferably 0.5 to 40% by mass, and still more preferably 2 to 27% by mass. By setting the content to 50% by mass or less, the releasability of the releasable cushioning member can be improved, and further, the abrasion resistance can be effectively improved.

The average particle diameter D50 of the needle-like particles is preferably 2 to 100. mu.m, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. The preferable range of the average particle diameter D50 of the dendritic particles is also preferably 2 to 100. mu.m, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. The average particle diameter D50 of the flaky particles is preferably 2 to 100 μm, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm.

The average particle diameter D50 can be measured by a laser diffraction/scattering method. Specifically, the particle size distribution is a value obtained by measuring each conductive fine particle with a cyclone-type dry powder sample module using, for example, a laser diffraction/scattering particle size distribution measuring device LS 13320 (manufactured by Beckman Coulter corporation), and is an average particle size of diameters at which the cumulative value of particles is 50% of the particle size. The measurement was performed with the refractive index set to 1.6. The average particle diameter D50 of each particle in the electromagnetic wave shielding member 1 was measured for 100 particle diameters using a Scanning Electron Microscope (SEM), and the power distribution was determined. In the case of needle-shaped particles and dendritic particles, the longest length of each particle is used as the particle diameter.

By using the dendritic particles and/or acicular particles and the scaly particles in combination, the number of contact points between the conductive fillers can be increased, and the shielding property can be improved. Further, by using the dendritic particles and/or the acicular particles in combination, the contact area with the binder component can be increased, the value of the kurtosis can be easily adjusted, and further, the scratch resistance can be improved. Therefore, the electromagnetic wave shielding member with high reliability can be provided.

The composition constituting the conductive adhesive layer may further contain a colorant, a flame retardant, an inorganic additive, a lubricant, an antiblocking agent, and the like.

Examples of the colorant include: organic pigments, carbon black, ultramarine, red iron powder (red iron oxide), zinc oxide, titanium oxide, graphite, and the like. Among them, the black coloring agent improves the visibility of the printed matter on the shielding layer.

Examples of the flame retardant include: halogen-containing flame retardants, phosphorus-containing flame retardants, nitrogen-containing flame retardants, inorganic flame retardants, and the like.

Examples of the inorganic additive include: glass fibers, silica, talc, ceramics, and the like.

Examples of the lubricant include: fatty acid esters, hydrocarbon resins, paraffins, higher fatty acids, fatty amides, fatty alcohols, metal soaps, modified silicones, and the like.

Examples of the anti-caking agent include: calcium carbonate, silica, polymethylsilsesquioxane, aluminum silicate, and the like.

The conductive adhesive layer may be any layer as long as the conductive filler is continuously in contact with the conductive adhesive layer by thermocompression bonding and has conductivity, and may not necessarily have conductivity at a stage before thermocompression bonding. The conductive adhesive layer can be formed by mixing and stirring a composition containing the conductive filler and a binder resin precursor, applying the mixture to a releasable substrate, and then drying the coated substrate. Alternatively, the resin composition may be formed by a method of directly applying the resin composition to the releasable cushioning member 3 and drying the same.

After the coating liquid of the conductive adhesive layer is applied, the conductive adhesive layer is formed on the releasable substrate by drying. The drying step is preferably carried out by heating (for example, 80 ℃ C. to 120 ℃ C.). In order to adjust the kurtosis of the electromagnetic wave shielding member, it is preferable to dry the electromagnetic wave shielding member at 25 ℃ (room temperature) and normal pressure for 1 to 10 minutes after the coating liquid is applied and before the heating and drying. The drying time at 25 ℃ C (room temperature) before the heat drying is more preferably 2 minutes to 6 minutes. The value of kurtosis can be adjusted by setting a process of drying at room temperature before heating and drying.

The influence of the viscosity of the coating liquid and the drying time at 25 ℃ before heating and drying on the kurtosis of the electromagnetic wave shielding member 1 will be described with reference to the schematic diagram of fig. 9. As shown in the figure, a coating liquid is applied to form the conductive adhesive layer 6 on the releasable substrate 15. The conductive adhesive layer 6P including the solvent in the course of drying can be obtained.

By setting the drying time at 25 ℃ to be long for the conductive adhesive layer 6P during heating, as shown in fig. 9, the state in which the evaporation rate of the solvent is slow is intentionally extended, and the downward sinking of the binder resin precursor 10 can be promoted. On the other hand, by setting the drying time at 25 ℃ short, as shown in fig. 9, the conductive filler 11 is easily raised by suppressing downward sinking of the binder resin precursor 10 and performing heat drying at the above stage. In addition, foaming is likely to occur with evaporation of the solvent, and the surface tends to be cracked.

In order to set the value of the kurtosis of the electromagnetic wave shielding member 1 to 8, it is preferable to set the solid content of the coating liquid to 20% to 50%. In order to adjust the kurtosis of the electromagnetic wave shielding member, it is preferable that the viscosity of the coating liquid measured by a B-type viscometer is in a range of 200MPa · s to 5000MPa · s. Further, in order to adjust the kurtosis of the electromagnetic wave shielding member, it is preferable that the thixotropic index of the coating liquid is 1.2 to 2.0. The conductive filler 11 in fig. 9 and fig. 10 described later is a scale-like particle, and a cross-sectional view of a cut portion in the thickness direction is shown, not in a plan view of the main surface.

The value of the kurtosis also varies depending on the viscosity of the coating liquid used for forming the conductive adhesive layer. The viscosity of the coating liquid is high, and the fluidity of the conductive filler tends to be suppressed. Therefore, when the viscosity is high, the conductive filler 11 tends to be random without being oriented. On the other hand, when the viscosity is low, the scaly particles tend to be oriented so that the main surface of the scaly particles is approximately opposed to the substrate surface. When the drying time at 25 ℃ is shortened and the heating and drying are performed, surface cracks due to foaming tend to be increased when the viscosity is high, and the conductive filler tends to move in the longitudinal direction easily when the viscosity is low.

Thus, the kurtosis can be adjusted by adjusting the viscosity of the coating liquid and the drying time at 25 ℃.

The degree of kurtosis of the electromagnetic wave shielding member 1 can also be adjusted by the particle diameter of the dendritic particles and/or acicular particles. The influence of the particle diameter of the dendritic particles and/or acicular particles on the kurtosis of the electromagnetic wave shielding member 1 will be described with reference to the schematic explanatory view of fig. 10. Similarly to fig. 9, by applying a coating liquid to form the conductive adhesive layer 6 on the releasable substrate 15, the conductive adhesive layer 6P can be obtained while being dried. In fig. 10, the same members or components as those in fig. 9 are denoted by the same reference numerals. As shown in fig. 10, when the average particle diameter D50 of the dendritic particles 12, which is one type of the conductive filler, is small, the value of the kurtosis tends to decrease, and conversely, when the average particle diameter D50 of the dendritic particles 12 is large, the value of the kurtosis tends to increase. Although it depends on the thickness of the conductive adhesive layer 6, the average particle diameter D50 may be set to 2 μm to 5 μm, for example, when the kurtosis value is to be decreased, the average particle diameter D50 may be set to 20 μm to 50 μm, for example, when the kurtosis value is to be increased, and the average particle diameter D50 may be set to exceed 5 μm and less than 20 μm, for example, when the kurtosis value is to be increased.

In order to adjust the kurtosis of the electromagnetic wave shielding member 1, it is preferable to apply a conductive adhesive composition for forming the conductive adhesive layer 6 as the outermost layer of the electromagnetic wave shielding member 2, dry the composition, and then perform corona treatment or plasma treatment. The corona treatment is preferably carried out with an irradiation amount of corona discharge electrons of 1W/m²/min～1,000W/m²Min, more preferablySet to 10W/m²/min～100W/m²/min。

The degree of peakedness of the electromagnetic wave shielding member 1 can be adjusted by increasing the amount of the needle-like or dendritic conductive filler added to the composition of the electromagnetic wave shielding member 2 before thermocompression bonding. The kurtosis of the electromagnetic wave shielding member 1 can also be adjusted by the average particle diameter D50 and the average particle diameter D90 of the conductive filler.

In embodiment a1, since the electromagnetic wave shielding member 2 includes a single conductive adhesive layer 6, the releasable cushion member 3 is laminated on the conductive adhesive layer 6. The lamination method may be a method using lamination.

The releasable substrate is a substrate having releasability on one or both surfaces, and is a sheet having a tensile strain at break at 150 ℃ of less than 50%. Examples of the releasable substrate include: examples of the thermoplastic resin include plastic sheets such as polyethylene terephthalate, polyethylene naphthalate, polyvinyl fluoride, polyvinylidene fluoride, rigid polyvinyl chloride, polyvinylidene chloride, nylon, polyimide, polystyrene, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, polycarbonate, polyacrylonitrile, polybutylene, flexible polyvinyl chloride, polyvinylidene fluoride, polyethylene, polypropylene, a polyurethane resin, an ethylene-vinyl acetate copolymer, and polyvinyl acetate, paper such as cellophane, tabby, kraft paper, and coated paper, various nonwoven fabrics, synthetic paper, metal foil, and composite films obtained by combining these materials.

(mold-releasable cushion Member)

The releasable cushioning member is a sheet that functions as a cushioning material for promoting the following property of the conductive adhesive layer to the electronic component and has releasability. That is, it is a layer that can be peeled off from the electromagnetic wave shielding member 1 after the thermocompression bonding step. Further, the layer is preferably a layer which has a tensile strain at break of 50% or more at 150 ℃ and melts at the time of thermocompression bonding.

The tensile strain at break of the releasable base material and the releasable cushioning member 3 is a value obtained by the following method. The releasable substrate and the releasable cushion member were cut into a size of 200mm in width × 600mm in length to obtain a measurement sample. A tensile TEST (TEST speed 50mm/min) was performed on the measurement sample at a temperature of 25 ℃ and a relative humidity of 50% using a bench top compact testing machine EZ-TEST (Shimadzu corporation). The tensile Strain at break (%) was calculated from the obtained S-S curve (Stress-Strain curve).

The releasable cushioning member 3 is preferably polyethylene, polypropylene, polyethersulfone, polyphenylene sulfide, polystyrene, polymethylpentene, polybutylene terephthalate, a cyclic olefin polymer, or silicone. Among them, polypropylene, polymethylpentene, polybutylene terephthalate, and silicone are more preferable from the viewpoint of achieving both embeddability and peelability. The releasable cushioning member may be used in a single layer or in multiple layers. When the layers are formed in multiple layers, sheets of the same or different types may be stacked.

The method of laminating the releasable cushioning member 3 and the conductive adhesive layer 6 is not particularly limited, and a method of laminating these sheets may be mentioned. Since the releasable cushioning member 3 is finally peeled off, a material having excellent releasability is preferable. The thickness of the releasable cushioning member is, for example, about 50 μm to 3mm, and more preferably about 100 μm to 1 mm.

[ embodiment A2]

Next, an example of an electronic component mounting board different from embodiment a1 will be described. The electronic component mounting substrate according to embodiment a2 is different from embodiment a1 in that the electromagnetic wave shielding member includes two electromagnetic wave shielding layers, and has the same basic configuration and manufacturing method as those of embodiment a1 except that the electromagnetic wave shielding member includes a single electromagnetic wave shielding layer. Note that description overlapping with embodiment a1 is omitted as appropriate.

As shown in fig. 11, the electromagnetic wave shielding member according to embodiment a2 is formed using an electromagnetic wave shielding laminate 4a including an electromagnetic wave shielding member 2a and a releasable cushion member 3a, wherein the electromagnetic wave shielding member 2a is a conductive adhesive layer 6a including two layers, i.e., a first conductive adhesive layer 6a1 and a second conductive adhesive layer 6a 2. The electromagnetic wave shielding laminate 4a is thermocompression bonded to cover an electromagnetic wave shielding member including a first electromagnetic wave shielding layer and a second electromagnetic wave shielding layer on a substrate on which an electronic component is mounted. By including two electromagnetic wave shielding layers, the degree of freedom in designing the electromagnetic wave shielding member can be improved. The second conductive adhesive layer 6a2 of the upper layer is manufactured by the same composition or steps as those of embodiment a1, and the first conductive adhesive layer 6a1 of the lower layer is not limited by the range of kurtosis and can be designed as required. For example, a layer using a filler such as fibrous particles or spherical particles as the conductive filler contained in the first conductive adhesive layer 6a1 can be used. The first conductive adhesive layer 6a1 may be an anisotropic conductive adhesive layer, and the second conductive adhesive layer 6a2 may be an isotropic conductive adhesive layer. In addition, a laminate of the electromagnetic wave reflection layer and the electromagnetic wave absorption layer is also preferable. Three or more electromagnetic wave shielding layers may be laminated.

According to the electronic component mounting substrate of embodiment a2, the same effects as those of embodiment a1 can be obtained by using the electromagnetic wave shielding member including the electromagnetic wave shielding layer having two layers. In addition, by laminating two electromagnetic wave shielding layers, the degree of freedom in designing each layer can be increased, and thus there is an advantage in that an electromagnetic wave shielding member corresponding to the demand can be easily provided.

[ embodiment A3]

The electronic component mounting substrate according to embodiment A3 is different from embodiment a1 in that the electromagnetic wave shielding member includes a laminate of an electromagnetic wave shielding layer and a hard coat layer, and has the same basic configuration and manufacturing method as those of the electromagnetic wave shielding member including a single electromagnetic wave shielding layer.

As shown in fig. 12, the electromagnetic wave shielding member according to embodiment a3 is formed using an electromagnetic wave shielding laminate 4b including an electromagnetic wave shielding member 2b and a releasable cushioning member 3b, wherein the electromagnetic wave shielding member 2b is a laminate of a conductive adhesive layer 6b and an insulating resin layer 7b, which are one layer. By thermocompression bonding the electromagnetic wave shielding laminate 4b, an electromagnetic wave shielding member including an electromagnetic wave shielding layer formed of the conductive adhesive layer 6b and a hard coat layer formed of the insulating resin layer 7b can be obtained on a substrate on which an electronic component is mounted. The electromagnetic wave shielding member of embodiment A3 has a kurtosis of 1 to 8 when measured from the hard coat side.

The insulating resin layer 7b is a layer formed of a resin composition containing a binder resin precursor and an inorganic filler. The binder resin precursor contains at least a thermo-softening resin. Examples of the thermosoftening resin and examples and suitable examples of the binder resin precursor are the same as the composition of the conductive adhesive layer of the electromagnetic wave shielding member described in embodiment a 1. The binder resin precursors of the conductive adhesive layer and the insulating resin layer may be the same or different.

The inorganic filler is not electrically conductive unlike the conductive adhesive layer of embodiment a1, but the preferable properties of the inorganic filler, such as shape, amount of blending, D50, D90, and the like, are the same as those of the conductive filler. Examples of the inorganic filler include: inorganic compounds such as silica, alumina, magnesium hydroxide, barium sulfate, calcium carbonate, titanium oxide, zinc oxide, antimony trioxide, magnesium oxide, talc, kaolinite, mica, basic magnesium carbonate, sericite, montmorillonite, kaolinite, and bentonite.

The heat-softening resin composition and the heat-softening resin composition layer may optionally contain a colorant, a silane coupling agent, an ion scavenger, an antioxidant, an adhesion-imparting resin, a plasticizer, an ultraviolet absorber, a leveling agent, a flame retardant, and the like.

According to the electronic component mounting substrate of embodiment A3, by using the electromagnetic wave shielding member having the hard coat layer, it is possible to provide an electromagnetic wave shielding member having more excellent durability because the electromagnetic wave shielding layer is coated with the hard coat layer in addition to the effects described in embodiment a 1.

[ embodiment A4]

The electronic component mounting substrate according to embodiment a4 is different from embodiment a1 in that the electromagnetic wave shielding member includes a laminate of an electromagnetic wave shielding layer and an insulating coating layer, and has the same basic configuration and manufacturing method as those of embodiment a1 except that the electromagnetic wave shielding member includes a single electromagnetic wave shielding layer.

As shown in fig. 13, the electromagnetic wave shielding member according to embodiment a4 is formed using an electromagnetic wave shielding laminate 4c including an electromagnetic wave shielding member 2c and a releasable cushioning member 3c, the electromagnetic wave shielding member 2c being a laminate of an insulating adhesive layer 8c and a conductive adhesive layer 6 c.

In embodiment a4, an example will be described in which an electromagnetic wave shielding member is coated on a substrate on which a plurality of electronic components (for example, semiconductor packages) are formed without a singulation step or after singulation. As shown in fig. 14A, an electromagnetic wave shielding laminate 4c is disposed above a substrate 20 on which an electronic component 30 having solder balls 24 functioning as connection terminals with the substrate 20 is mounted, and thermocompression bonding is performed from the side of a releasable buffer member 3c toward the substrate 20 on which the electronic component 30 is mounted (fig. 14B). Thereafter, the releasable buffer member 3C is peeled off, whereby the electronic component mounting substrate 53 in which the electromagnetic wave shielding member 1C is laminated in fig. 14C can be obtained.

The obtained electronic component mounting substrate 53 can be grounded from the upper surface of the electromagnetic wave shielding layer 5 c. Instead of the above method, a ground pattern may be provided on the substrate 20, and the insulating coating layer 9c may be pierced to conduct the ground pattern to the electromagnetic wave shielding layer 5c, and a conductive connector portion that conducts the ground pattern to the electromagnetic wave shielding layer 5c may be provided on the ground pattern.

In embodiment a4, an example of a method for manufacturing an electronic component mounting substrate that does not require a singulation step has been described, but an electronic component mounting substrate shown in fig. 14C may be obtained by forming the unit cells of the product unit of fig. 14C in an array on a motherboard, placing the electromagnetic wave shielding laminate 4C thereon, and performing a hot-pressing process to form an electromagnetic wave shielding layer, and then performing a singulation step.

The insulating adhesive layer 8c is a layer formed of a resin composition containing a binder resin precursor. The binder resin precursor contains at least a thermo-softening resin. Examples and suitable examples of the binder resin precursor include those of the electrical adhesive layer described in embodiment a 1. The binder resin precursors of the insulating adhesive layer 8c and the conductive adhesive layer 6c may be the same or different.

The heat-softening resin composition and the heat-softening resin composition layer may optionally contain a colorant, a silane coupling agent, an ion scavenger, an antioxidant, an adhesion-imparting resin, a plasticizer, an ultraviolet absorber, a leveling agent, a flame retardant, an inorganic filler, and the like.

According to the electronic component mounting board of embodiment a4, by using the electromagnetic wave shielding member 1c having the insulating coating layer 9c, in addition to the effects described in embodiment a1, it is possible to prevent a short circuit between the electromagnetic wave shielding member and a conductor portion such as a circuit or an electrode pattern other than a ground pattern, and to improve the reliability of bonding between the electronic component and the electromagnetic wave shielding layer. In addition, the insulation reliability of the electronic component can be improved. Therefore, an electromagnetic wave shielding member having excellent durability can be provided. As a result, an electronic component mounting substrate having excellent electromagnetic wave shielding properties can be provided. In addition, since the shield layer can be formed over the entire substrate at one time, there is an advantage that the manufacturing process is simple and the thickness can be reduced significantly compared to a shield case or the like.

Further, in embodiment a4, the example in which the insulating coating layer 9c is mainly used to reinforce the bonding of the electronic component and the electromagnetic wave shielding member is described, but the insulating coating layer 9c may be applied to a sealing material. When the insulating coating layer 9c is applied to the sealing material, there is an advantage that the sealing step of the semiconductor chip or the like and the coating of the electromagnetic wave shielding member can be performed in the same step. That is, the electromagnetic wave shielding member of embodiment a4 can be applied to an electronic component that is not integrally covered with an insulator, and an insulating covering layer corresponding to a sealing material (mold resin) is obtained from an insulating adhesive layer. In this case, in order to cover the electromagnetic wave shielding member on the side surface of the electronic component, a platen in which concave portions corresponding to the electronic component are formed in an array (a platen in which convex portions for embedding the electromagnetic wave shielding member in the gap of the electronic component are formed) may be used.

[ embodiment A5]

The electronic component mounting substrate according to embodiment a5 uses the following electromagnetic wave shielding laminate: the electromagnetic wave shielding layer is in direct contact with and electrically connected to the ground pattern, and the conductive adhesive layer located in the internal layer of the electromagnetic wave shielding laminate has a region exposed at the stage of the laminate. The exposed region is provided for electrically connecting a conductive pattern such as a ground pattern formed on a substrate or the like to the electromagnetic wave shielding layer. Embodiment a5 differs from embodiment a4 in these points, and has the same basic configuration and manufacturing method.

The lamination configuration of the electromagnetic wave shielding laminate of embodiment a5 is the same as that of embodiment a4, but as shown in fig. 15A, the conductive adhesive layer 6d is exposed in the electromagnetic wave shielding laminate 4d at a position corresponding to a region covering the ground pattern 22 formed on the substrate 20. Specifically, in a plan view from the insulating adhesive layer 8d side, an exposed region of the conductive adhesive layer 6d is provided. In the example of the electromagnetic wave shielding laminate 4d in fig. 15A, the insulating adhesive layer 8d is made smaller in size than the electromagnetic wave shielding laminate 4d by one turn, and the conductive adhesive layer 6d is exposed in the edge region of the electromagnetic wave shielding laminate 4 d. With the above configuration, as shown in fig. 15B and 15C, the electronic component mounting substrate 54 in which the ground pattern 22 and the electromagnetic wave shielding layer 5d are brought into contact and electrically conducted by thermocompression bonding can be obtained. The position of the exposed portion of the conductive adhesive layer 6d of the electromagnetic wave-shielding laminate 4d is not limited to the example of fig. 15A, and the exposed portion may be formed as an opening pattern.

[ [ embodiment B ] ]

A specific example of the electronic component mounting board according to embodiment B will be described below.

[ embodiment B1]

< electronic component mounting substrate >

The electronic component mounting board according to embodiment B1 uses the electromagnetic wave shielding member specified in embodiment B instead of the electromagnetic wave shielding member specified in embodiment a. The electronic component mounting board according to embodiment B1 and the manufacturing method thereof have the same basic configuration and manufacturing method as those of embodiment a1, except that the electromagnetic wave shielding member according to embodiment B is used and the other points are described. Therefore, redundant descriptions are omitted as appropriate.

As a preferable example of the basic configuration of the electronic component mounting board according to embodiment B1, the basic configuration of the electronic component mounting board according to embodiment a1 described above with reference to fig. 1 to 10 can be exemplified. Hereinafter, the features of embodiment B1 will be described with reference to these drawings.

< electromagnetic wave shielding member >

The electromagnetic wave shielding member 1 of embodiment B1 is obtained as described in embodiment a1 by: after the electromagnetic wave shielding laminate is placed on the top surface of the electronic component 30 mounted on the substrate 20, the electronic component 30 and the substrate 20 are covered by thermal compression. The electromagnetic wave shielding member 1 has the same coating form as that of embodiment a1, and therefore is omitted.

As in embodiment a1, the electromagnetic wave shielding member 1 of embodiment B1 can be formed using an electromagnetic wave shielding laminate. As shown in fig. 4, the electromagnetic wave shielding laminate 4 includes an electromagnetic wave shielding member 2 and a mold-releasable cushioning member 3. As in embodiment a1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 and the substrate 20 by thermocompression bonding to form the electromagnetic wave shielding layer 5. In embodiment a1, the electromagnetic wave-shielding layer 5 functions as the electromagnetic wave-shielding member 1.

As described in embodiment a1, the electromagnetic wave shielding member 2 according to embodiment B1 may be formed of a laminate of other layers, such as a laminate of two or more conductive adhesive layers, a laminate of a conductive adhesive layer and a hard coat layer, or a laminate of an insulating adhesive layer and a conductive adhesive layer.

The electromagnetic wave shielding layer 5 of embodiment B1 contains a binder resin and a conductive filler. The conductive filler in the electromagnetic wave-shielding layer 5 is continuously contacted and exhibits conductivity. From the viewpoint of improving the electromagnetic wave shielding property, the sheet resistance value of the electromagnetic wave shielding layer 5 is preferably 1 Ω/□ or less.

The electromagnetic wave shielding member 1 according to embodiment B1 has a press-fitting elastic modulus of 1GPa to 10 GPa. By setting the press-fitting elastic modulus to the above range, local minute deformation of the electromagnetic wave shielding member 1 with respect to stress can be suppressed, and as a result, damage of the electromagnetic wave shielding member 1 due to burr generation can be effectively suppressed. Further, since PCT resistance is excellent, a decrease in adhesion after the reflow step can be effectively suppressed. Therefore, the electronic component mounting board with high quality can be provided.

By setting the press-fitting elastic modulus of the electromagnetic wave shielding member 1 of embodiment B1 to 1GPa or more, deformation of the electromagnetic wave shielding member 1 can be suppressed with respect to stress received from a cutting tool such as a dicing blade in a cutting step, and burrs of the electromagnetic wave shielding member 1 generated in a manufacturing step can be effectively suppressed (see fig. 23 (i)). The burr described in the present specification means a curl-up of the electromagnetic wave shielding member with the cut surface of the electromagnetic wave shielding member 1 as a base point.

The press-fitting elastic modulus of the electromagnetic wave shielding member 1 of embodiment B1 can be adjusted by the composition of the electromagnetic wave shielding member 2 in the electromagnetic wave shielding laminate 4 described later before the thermal compression bonding. More specifically, the type of the binder resin precursor, the amount of each component, and the like in the composition for forming the electromagnetic wave shielding member 2 before thermocompression bonding of the electromagnetic wave shielding member 1 can be adjusted. Specifically, the larger the filler content is, the larger the indentation modulus tends to be. In addition, the number of functional groups of the resin used as the binder resin precursor and the content of the curable compound are increased, and thus the indentation elastic modulus tends to be increased. Further, the higher the hardness of the binder resin, the higher the indentation elastic modulus tends to be. Therefore, it is preferable that the type of the binder resin precursor for forming the binder resin and the crosslinking density of the binder resin be appropriate. The crosslinking density can be easily adjusted by the types of the resin and the curable compound or the number of functional groups.

The indentation elastic modulus may be considered to be a young's modulus representing a property corresponding to deformation of a material caused by an external stress. The "indentation elastic modulus" in the present specification means a value obtained by a measurement method and measurement conditions described in examples described later.

A more preferable range of the press-fitting elastic modulus of the electromagnetic wave shielding member 1 of embodiment B1 is more than 1.5GPa and 8GPa or less, and a further more preferable range is 2GPa or more and 7.4GPa or less.

The film thickness of the electromagnetic wave shielding member 1 according to embodiment B1 can be appropriately selected depending on the application. In applications where thinning is required, the thickness T1 and the thickness T2 of the electromagnetic wave shielding member 1 covering the upper surface of the electronic component are set to be, for example, about 10 μm to 200 μm.

The electronic part 30 is sometimes imprinted with product information. In this case, there are a method of forming the electromagnetic wave shielding member 1 after the electronic component 30 is imprinted, and a method of forming the electromagnetic wave shielding member 1 in the electronic component 30 and then imprinting the electromagnetic wave shielding member. In either case, the uniform side maintaining high shielding properties requires good visibility of the imprint. From the viewpoint of satisfying both properties, the film thickness T1 of the electromagnetic wave shielding member is preferably 10 μm or more, and more preferably 20 μm or more. In the latter imprint method, when the electromagnetic wave shielding member is printed immediately, there is no upper limit to the film thickness of the electromagnetic wave shielding member. On the other hand, in the former imprint method, i.e., in the case of directly imprinting an electronic component, the upper limit of the film thickness T1 of the electromagnetic wave shielding member is preferably 50 μm or less, and more preferably 30 μm or less, in order to maintain the visibility of the imprint.

The water contact angle of the surface layer of the electromagnetic wave shielding member 1 according to embodiment B1 is preferably 70 ° to 110 °. By setting the above range, damage of the electromagnetic wave shielding layer during the manufacturing process can be more effectively suppressed. Further, when the mold-releasable cushioning member filled in the groove-like recessed portion formed in the half-cut groove 25 of the electronic component 30 is peeled from the electromagnetic wave shielding member 1, the generation of burrs can be suppressed. A more preferable range of the water contact angle of the electromagnetic wave shielding member is 75 ° to 105 °, and a further more preferable range is 80 ° to 100 °. The value of the water contact angle of the electromagnetic wave shielding member can be adjusted by the amount of the surface conditioner added to the composition for forming the electromagnetic wave shielding member. As the amount of the surface conditioner added to the electromagnetic wave shielding member 1 increases, the value of the water contact angle tends to increase.

In order to further improve the pressure cooker (hereinafter, also referred to as PCT) test performance, it is preferable that the electromagnetic wave shielding member 1 of embodiment B1 have a mahalanobis hardness of 50N/mm²The above range. The electromagnetic wave shielding member 1 has a press-fitting elastic modulus in the range of 1GPa to 10GPa, and further has a combination of 50N/mm²The above mohs hardness further improves the adhesion after the pressure cooker test. As a result, the electromagnetic wave shielding member 1 having excellent adhesion even after reflow soldering can be provided. The Martensitic hardness is more preferably 60N/mm²More preferably 70N/mm as described above²The above.

The mahalanobis hardness can be adjusted by the hardness of the conductive filler and the binder component. The hardness of the binder component mainly depends on the hardness of the cured product of the thermosetting resin and the curable compound. Specifically, the mahalanobis hardness tends to increase with the addition of the scale-like particles, and the mahalanobis hardness tends to decrease with the addition of the spherical or dendritic particles. In addition, when the amount of the conductive filler is increased, the mahalanobis hardness tends to be increased. Further, the higher the hardness of the resin after curing, the harder the mahalanobis hardness becomes.

The manufacturing method will be described later, but from the viewpoint of improving the releasability when peeling the releasable cushion member from the electromagnetic wave shielding member 1 after thermocompression bonding the electromagnetic wave shielding laminate 4 to the substrate 20 on which the electronic component 30 is mounted, it is preferable to bond the surface layer of the electromagnetic wave shielding member 1 to the substrate in accordance with JISB 0601: 2001 is 8 or less. It is considered that when the peak value of the surface shape of the electromagnetic wave shielding member 1 is set to 8 or less, the peak value becomes appropriate, and the releasability cushioning member 3 and the electromagnetic wave shielding member 1 are easily peeled off. As a result, the mold-releasable cushioning member 3 can be effectively prevented from being broken in the half-cut groove 25 in the gap between the electronic components and remaining as a residue. In the present specification, the term "chips" refers to a releasable cushioning member that is broken when the releasable cushioning member is peeled off and remains in a groove that is a gap of an electronic component.

In addition, from the viewpoint of improving the abrasion resistance, it is preferable that the degree of kurtosis of the electromagnetic wave shielding member 1 of embodiment B1 is 1 or more. By setting to 1 or more, the steel wool resistance can be improved. A more preferable range of the kurtosis of the electromagnetic wave shielding member is 1.5 to 6.5, and a further more preferable range is 2 to 4. The method of adjusting the kurtosis of the surface of the electromagnetic wave shielding member 1 is as described in embodiment a 1.

The root-mean-square height Rq of the surface of the electromagnetic wave shielding member 1 of embodiment B1 is preferably in the range of 0.4 μm to 1.6 μm, more preferably 0.5 μm to 1.5 μm, and still more preferably 0.7 μm to 1.2 μm. In the present specification, the kurtosis and the root mean square height are values obtained by the methods described in the examples described later.

< method for manufacturing electronic component mounting substrate >

A method of manufacturing the electromagnetic wave shielding member 1 of embodiment B1 is basically the same as the method of manufacturing the electromagnetic wave shielding member 1 of embodiment a 1. In the step (c), the binder resin constituting the electromagnetic wave-shielding layer 5 is preferably constructed to have a three-dimensional crosslinked structure from the viewpoint of improving the tape adhesiveness after PCT. When dicing is performed in the singulation step of step (e), high-pressure water washing may be performed in order to cool the frictional heat generated by dicing and to wash away the dicing debris generated by dicing. In the electronic component mounting substrate 51 according to embodiment B, the peeling of the electromagnetic wave shielding member 1 due to the impact of high-pressure washing can be significantly improved by setting the press-fitting elastic modulus to 1GPa to 10 GPa.

< laminate for electromagnetic wave shielding >

As described with reference to fig. 4, the electromagnetic wave shielding laminate according to embodiment B1 includes two layers, i.e., an electromagnetic wave shielding member 2 and a mold-releasable cushioning member 3. In embodiment B1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 or the substrate 20 through a thermocompression bonding step, and functions as the electromagnetic wave shielding layer 5.

(conductive adhesive layer)

Suitable examples of the thermo-softening resin are the same as those of embodiment a 1. The thermo-softening resin may have a plurality of functional groups available for a crosslinking reaction by heating as a thermosetting resin. Specific examples of the functional group are the same as those in embodiment A1.

The curable compound has a functional group capable of crosslinking with a reactive functional group of the thermosetting resin. Crosslinking can improve the adhesion and water resistance. The hardening compound is preferably an epoxy compound, a compound having an acid anhydride group, an isocyanate compound, a polycarbodiimide compound, an amine compound such as an aziridine compound, a dicyanodiamide compound or an aromatic diamine compound, a phenol compound such as a phenol novolac resin, an organic metal compound, or the like. The curable compound may also be a resin. In this case, the thermosetting resin and the curable compound are classified into those having a larger content and those having a smaller content.

The epoxy compound is a compound having two or more epoxy groups in 1 molecule. The epoxy compound may be in a liquid or solid state. As the epoxy compound, for example, a glycidyl ether type epoxy compound, a glycidyl amine type epoxy compound, a glycidyl ester type epoxy compound, a cyclic aliphatic (alicyclic type) epoxy compound, and the like are preferable.

Examples of the glycidyl ether type epoxy compound include: bisphenol a type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, bisphenol AD type epoxy compounds, cresol novolac type epoxy compounds, phenol novolac type epoxy compounds, α -naphthol novolac type epoxy compounds, bisphenol a novolac type epoxy compounds, dicyclopentadiene type epoxy compounds, tetrabromobisphenol a type epoxy compounds, brominated phenol novolac type epoxy compounds, tris (glycidoxyphenyl) methane, tetrakis (glycidoxyphenyl) ethane, and the like.

Examples of the glycidyl amine type epoxy compound include: tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, tetraglycidyl-m-xylylenediamine, and the like.

Examples of the glycidyl ester type epoxy compound include: diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate, and the like.

Examples of the cyclic aliphatic (alicyclic) epoxy compound include: epoxycyclohexylmethyl-epoxycyclohexane carboxylate, bis (epoxycyclohexyl) adipate, and the like. In addition, a liquid epoxy compound can be suitably used.

The imidazole compound includes imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2, 4-dimethylimidazole, and 2-phenylimidazole, and further includes latent curing accelerators having improved storage stability, such as a type in which the imidazole compound is reacted with an epoxy resin so as to be insoluble in a solvent, or a type in which the imidazole compound is encapsulated in a microcapsule, and among these, a latent curing accelerator is preferable from the viewpoint of starting curing after the conductive adhesive layer is thermally melted.

The structure and molecular weight of the curable compound can be appropriately designed according to the application. From the viewpoint of adjusting the indentation elastic modulus to a range of 1GPa to 10GPa to effectively suppress burrs, it is preferable to use two or more curable compounds having different molecular weights. The use of the first curable compound and the second curable compound also has an effect of increasing the tensile strain at break of the electromagnetic wave shielding layer.

The curable compound is contained preferably in an amount of 1 to 70 parts by mass, more preferably 3 to 65 parts by mass, and still more preferably 3 to 60 parts by mass, based on 100 parts by mass of the thermosetting resin. When the first curable compound and the second curable compound are used in combination, the first curable compound is contained in an amount of preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and still more preferably 20 to 30 parts by mass, based on 100 parts by mass of the thermosetting resin. On the other hand, the second curable compound is preferably contained in an amount of 0 to 40 parts by mass, more preferably 5 to 30 parts by mass, and still more preferably 10 to 20 parts by mass, based on 100 parts by mass of the thermosetting resin.

Suitable examples of the thermoplastic resin are the same as those in embodiment a 1. The conductive filler may be exemplified by a metal filler, conductive ceramic particles, and a mixture thereof. Suitable examples of the metal filler are the same as those of embodiment a 1. The silver content of the silver-plated copper is also the same as that of embodiment a 1. Further, in the case of the core-shell particles, the suitable range of the coating rate of the coating layer with respect to the core portion is also the same as that of embodiment a 1. The core may be a nonmetal, but from the viewpoint of conductivity, a conductive material is preferable, and metal particles are more preferable.

As the conductive filler, an electromagnetic wave absorbing filler can be used, and a specific example thereof is the same as in embodiment a 1.

Examples of the shape of the conductive filler used in the conductive adhesive layer include scale-like particles, dendritic particles, needle-like particles, plate-like particles, grape-like particles, fibrous particles, and spherical particles. From the viewpoint of adjusting the value of the kurtosis, a conductive filler containing needle-shaped particles and/or dendritic particles is preferable. Here, the needle-like shape means a shape having a major diameter three times or more as large as a minor diameter, and includes a spindle shape, a cylindrical shape, and the like in addition to the needle-like shape. The term "dendritic" means a shape in which a plurality of branches extend two-dimensionally or three-dimensionally from a rod-like main axis when observed by an electron microscope (500 to 20,000 times). In a dendrimer, the branches may also be bent or extend further from the branch.

Further, by containing the flaky particles as the conductive filler, an electromagnetic wave shielding member having excellent covering properties can be provided. Here, the scale-like shape also includes a flake shape and a plate shape. The conductive filler may be in the form of an ellipse, a circle, or a slit around the fine particle, as long as the entire particle is in the form of a scale. The scale-like particles tend to have a high mahalanobis hardness, and the spherical and dendritic particles tend to have a low mahalanobis hardness. In addition, when the amount of the conductive filler is increased, the mahalanobis hardness tends to be increased. Further, the higher the hardness of the resin after curing, the harder the mahalanobis hardness becomes.

The conductive fillers may be used alone or in combination. For example, the following may be exemplified: a combination of scale-like particles and spherical particles; a combination of scaly particles and dendritic particles; a combination of scaly and acicular particles; a combination of scaly particles, dendritic particles and acicular particles. Further, spherical particles of nanometer size may be used in combination.

In addition, by using the dendritic particles and/or the needle-like particles in combination, the number of contact points of the conductive fillers can be increased, and the shielding property can be improved. In addition, by using the dendritic particles and/or the acicular particles in combination, the contact area with the binder component can be increased, and therefore a high-quality electromagnetic wave shielding member can be provided.

The needle-like particles and/or dendritic particles are preferably contained in an amount of 50 mass% or less based on 100 mass% of the conductive filler in the conductive adhesive layer. More preferably 0.5 to 40% by mass, still more preferably 1 to 35% by mass, and particularly preferably 1 to 30% by mass. By containing 50% by mass or less, an electromagnetic wave shielding member having more excellent abrasion resistance can be provided.

The average particle diameter D50 of the flaky particles is preferably 2 to 100. mu.m. The scale-like particles may be mixed with a nanosize conductive filler.

The average particle diameter D50 of the needle-like particles is preferably 2 to 100. mu.m, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. The preferable range of the average particle diameter D50 of the dendritic particles is also preferably 2 to 100. mu.m, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. The average particle diameter D50 of the flaky particles is preferably 2 to 100 μm, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. By using the scaly particles and the dendritic particles in combination, the surface glossiness is optimized, and when characters are directly printed on the electromagnetic wave shielding layer, the visibility of printed characters can be improved.

The method for measuring the average particle diameter D50 is as described in embodiment a 1. The composition constituting the conductive adhesive layer may contain the additives described in embodiment a1 (a colorant, a flame retardant, an inorganic additive, a lubricant, an antiblocking agent, and the like). Specific examples of the additives are the same as those in embodiment a 1.

After the coating liquid of the conductive adhesive layer is applied, the conductive adhesive layer is formed on the releasable substrate by drying. The drying step is preferably carried out by heating (for example, 80 ℃ C. to 120 ℃ C.). From the viewpoint of adjusting the kurtosis of the electromagnetic wave shielding member, it is preferable that the coating liquid is applied and dried at 25 ℃ (room temperature) and normal pressure for 1 to 10 minutes before being heated and dried. The drying time at 25 ℃ C (room temperature) before the heat drying is more preferably 2 minutes to 6 minutes. The value of kurtosis can be adjusted by setting a process of drying at room temperature before heating and drying.

The influence of the viscosity of the coating liquid and the drying time at 25 ℃ before heating and drying on the kurtosis of the electromagnetic wave shielding member 1 will be described with reference to the schematic diagram of fig. 9. As shown in the figure, a coating liquid is applied to form the conductive adhesive layer 6 on the releasable substrate 15. The conductive adhesive layer 6P including the solvent in the course of drying can be obtained. The electromagnetic wave shielding laminate can be produced by the same method as that of embodiment a 1.

[ embodiment B2]

Next, an example of an electronic component mounting board different from embodiment B1 will be described. The electronic component mounting substrate according to embodiment B2 differs from embodiment B1 in that the electromagnetic wave shielding member includes two electromagnetic wave shielding layers, and has the same basic configuration and manufacturing method as those of embodiment B1 except that the electromagnetic wave shielding member includes a single electromagnetic wave shielding layer. The basic configuration and manufacturing method are the same as those of embodiment a2, except that the electromagnetic wave shielding member of embodiment B is used instead of the electromagnetic wave shielding member of embodiment a, or the electromagnetic wave shielding member of embodiment a is used as described above. Duplicate descriptions are omitted as appropriate.

As shown in fig. 11, the electromagnetic wave shielding member according to embodiment B2 is formed using an electromagnetic wave shielding laminate 4a including an electromagnetic wave shielding member 2a and a releasable cushion member 3a, wherein the electromagnetic wave shielding member 2a is a conductive adhesive layer 6a including two layers, i.e., a first conductive adhesive layer 6a1 and a second conductive adhesive layer 6a 2. The electromagnetic wave shielding laminate 4a is thermocompression bonded to cover the substrate 20 on which the electronic component 30 is mounted with the electromagnetic wave shielding member including the first electromagnetic wave shielding layer and the second electromagnetic wave shielding layer. In the electromagnetic wave shielding member which is a laminate of the two electromagnetic wave shielding layers, the indentation elastic modulus when measured from the surface layer side is set to 1GPa to 10 GPa. By including two electromagnetic wave shielding layers, the degree of freedom in designing the electromagnetic wave shielding member can be improved. For example, a laminate of an electromagnetic wave reflection layer and an electromagnetic wave absorption layer can be exemplified. Three or more electromagnetic wave shielding layers may be laminated.

According to the electronic component mounting substrate of embodiment B2, the same effects as those of embodiment B1 can be obtained by using the electromagnetic wave shielding member including the electromagnetic wave shielding layer having two layers. In addition, by laminating two electromagnetic wave shielding layers, the degree of freedom in designing each layer can be increased, and thus there is an advantage in that an electromagnetic wave shielding member corresponding to the demand can be easily provided.

Embodiment B3 to embodiment B5

The electronic component mounting substrates according to embodiments B3 to B5 and the methods for manufacturing the same can be described with reference to embodiments A3 to a5, except that the electromagnetic wave shielding member according to embodiment B (including the description of embodiments B1 and B2) is used instead of the electromagnetic wave shielding member according to embodiment a. Therefore, descriptions of the electronic component mounting boards and the methods of manufacturing the electronic component mounting boards according to embodiments B3 to B5 are omitted.

[ [ embodiment C ] ]

A specific example of the electronic component mounting board of embodiment C will be described below.

[ embodiment C1]

< electronic component mounting substrate >

The electronic component mounting board according to embodiment C1 uses the electromagnetic wave shielding member according to embodiment C instead of the electromagnetic wave shielding member according to embodiment a. The electronic component mounting board according to embodiment C1 and the manufacturing method thereof have the same basic configuration and the same manufacturing method as those of embodiment a1, except for the electromagnetic wave shielding member according to embodiment C1 and other points described above. Therefore, the same description is omitted as appropriate.

As a suitable example of the basic configuration of the electronic component mounting board according to embodiment C1, the basic configuration of the electronic component mounting board according to embodiment a1 described above with reference to fig. 1 to 10 can be exemplified. Hereinafter, the features of embodiment C1 will be described with reference to these drawings.

< electromagnetic wave shielding member >

The electromagnetic wave shielding member 1 of embodiment C1 is obtained as described in embodiment a1 by: after the electromagnetic wave shielding laminate is placed on the top surface of the electronic component 30 mounted on the substrate 20, the electronic component 30 and the substrate 20 are covered by thermal compression. The electromagnetic wave shielding member 1 has the same coating form as that of embodiment a1, and therefore is omitted.

As in embodiment a1, the electromagnetic wave shielding member 1 of embodiment C1 can be formed using an electromagnetic wave shielding laminate. As shown in fig. 4, the electromagnetic wave shielding laminate 4 includes an electromagnetic wave shielding member 2 and a mold-releasable cushioning member 3. As in embodiment a1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 and the substrate 20 by thermocompression bonding to form the electromagnetic wave shielding layer 5. The electromagnetic wave shielding layer 5 functions as the electromagnetic wave shielding member 1.

As described in embodiment a1, the electromagnetic wave shielding member 2 of embodiment C1 may be formed of a laminate of other layers, such as a laminate of two or more conductive adhesive layers, a laminate of a conductive adhesive layer and a hard coat layer, or a laminate of an insulating adhesive layer and a conductive adhesive layer.

The electromagnetic wave-shielding layer 5 according to embodiment C1 includes a binder resin and a conductive filler. The conductive filler in the electromagnetic wave-shielding layer 5 is continuously contacted and exhibits conductivity. From the viewpoint of improving the electromagnetic wave shielding property, the sheet resistance value of the electromagnetic wave shielding layer 5 is preferably 1 Ω/□ or less.

The electromagnetic wave shielding member 1 has a surface layer formed by laminating a plurality of layers in accordance with JISB 0601: 2001, the root mean square height Rq is 0.05 μm or more but less than 0.3. mu.m. The root-mean-square height Rq is a parameter corresponding to a standard deviation of a distance from the average plane, corresponds to a standard deviation of a height, and is represented by the following equation (2) with z (x) being a change in height of the surface along one axis (x axis). L is a reference length.

[ mathematical formula 3]

As a result of extensive studies, the present inventors have found that, by setting the root mean square height Rq to a range of 0.05 μm or more and less than 0.3 μm as the shape of the contact interface of the surface layer of the electromagnetic wave shielding member 1, cracks in the electromagnetic wave shielding member can be effectively prevented in the cold-heat cycle test (-50 ℃ to 125 ℃) and an electromagnetic wave shielding member having excellent covering properties can be provided. Therefore, the electronic component mounting substrate with high reliability can be provided. The electronic component mounting board according to the present embodiment is particularly suitable as an electronic component mounting board used for an electronic device (for example, an electronic component mounting board mounted on an automobile) in which an electronic component used in a severe environment with a large temperature difference is used.

In the manufacturing process of the electronic component mounting substrate, the following steps may be performed: the electromagnetic wave shielding member is fixed to the cutting table via the dicing tape, and is singulated from the substrate side into individual products while maintaining the above state. In this case, the dicing tape and the electromagnetic wave shielding member are peeled off after the completion of the step, but in this case, floating (partial poor adhesion) or peeling may occur between the electromagnetic wave shielding member and the electronic component. According to the electronic component mounting substrate of the present embodiment, the root mean square height Rq of the surface layer of the electromagnetic wave shielding member is set to 0.05 μm or more and less than 0.3 μm, whereby the above-described problem can be effectively solved.

According to the present embodiment, since the electromagnetic wave shielding layer has excellent cooling/heating cycle resistance, excellent adhesion to the electronic component after the singulation step, and excellent covering properties, it is possible to provide the electronic component mounting substrate with high reliability.

In addition, the electronic component mounting board may be subjected to a high-temperature treatment such as a reflow step, but in this case, a substance in the electronic component mounting board, for example, a component of a solder flux may adhere to the electromagnetic wave shielding member 101. In view of the above problem, a more excellent effect can be exhibited by setting the root mean square height Rq of the surface layer of the electromagnetic wave shielding member of embodiment C1 to 0.05 μm or more and less than 0.3 μm. That is, the adhesion of the substance on the electromagnetic wave shielding member 1 is effectively prevented. The reason for this is considered to be: the irregularities on the surface of the electromagnetic wave shielding member 1 are formed to be appropriate irregularities, and it is possible to effectively prevent substances such as components of the solder flux from remaining on the irregularities.

From the viewpoint of achieving excellent coating properties in the cold-hot cycle test, the root mean square height Rq of the electromagnetic wave shielding member of embodiment C1 is preferably in the range of 0.05 μm to 0.29 μm, more preferably in the range of 0.05 μm to 0.27 μm, and particularly preferably in the range of 0.05 μm to 0.25 μm.

The root mean square slope Rdq of the surface layer of the electromagnetic wave shielding member 1 according to embodiment C1 is preferably in the range of 0.05 to 0.4, more preferably 0.05 to 0.37, and still more preferably 0.1 to 0.35. In the present specification, the root-mean-square height Rq and the root-mean-square slope Rdq are in accordance with JISB 0601: 2001 are values obtained by measurement, and are values obtained by the methods described in the examples described later. By setting the root mean square slope Rdq to 0.05 to 0.4, the antifouling property and the crack can be more effectively improved.

The root mean square slope Rdq is the root mean square of the local slope dz/dx in the reference length, and is expressed by the following equation (3).

[ mathematical formula 4]

Rdq can be calculated by processing the surface shape obtained by any one of an optical microscope, a laser microscope, and an electron microscope with analysis software. Rdq is a parameter expressing the steepness of surface irregularities. As the parameters expressing the properties of the surface, an arithmetic average height Ra, a maximum height Rz, and a maximum height Rq can be used, but these are parameters representing only the height of the irregularities, and are not suitable for accurately representing the state of the surface.

The larger the value of Rdq, the steeper the surface unevenness becomes. That is, the degree of surface irregularity steepness can be determined from the numerical value of Rdq.

The root-mean-square height Rq and the root-mean-square slope Rdq of the surface of the electromagnetic wave shielding member 1 of embodiment C1 can be adjusted by the manufacturing process of the electromagnetic wave shielding member 2 in the electromagnetic wave shielding laminate 4. The composition of the composition for forming the electromagnetic wave shielding member before thermocompression bonding of the electromagnetic wave shielding member 1 and the amount of the composition can be adjusted. Details will be described later. Further, the present inventors have made extensive studies and have confirmed that by adding an amount of the conductive filler capable of functioning as an electromagnetic wave shielding layer, the values of the root-mean-square height Rq and the root-mean-square slope Rdq do not substantially change before and after the reflow process, or the change amount is small even if they change. It has been confirmed that by adding an inorganic filler to an insulating layer such as a hard coat layer disclosed in the embodiment described later, the values of the root mean square height Rq and the root mean square slope Rdq do not substantially change before and after the reflow process, or the change amount is small even if the change amount changes.

The water contact angle of the surface layer of the electromagnetic wave shielding member 1 according to embodiment C1 is preferably 90 ° to 130 °. By setting the range, the floating can be more effectively suppressed, and the antifouling property can be more effectively suppressed. A more preferable range of the water contact angle of the electromagnetic wave shielding member is 95 ° to 125 °, and a further more preferable range is 100 ° to 120 °. The value of the water contact angle of the electromagnetic wave shielding member can be adjusted by the amount of the surface conditioner added to the composition for forming the electromagnetic wave shielding member. As the amount of the surface conditioner added to the electromagnetic wave shielding member 1 increases, the value of the water contact angle tends to increase.

< method for manufacturing electronic component mounting substrate >

A method of manufacturing the electromagnetic wave shielding member 1 of embodiment C1 is basically the same as the method of manufacturing the electromagnetic wave shielding member 1 of embodiment a 1. The thickness of the conductive adhesive layer 6 is set to be such that the electromagnetic wave shielding layer 5 can be formed so as to cover the top and side surfaces of the electronic component 30 and the exposed surface of the substrate 20. Although it may vary depending on the fluidity of the binder resin precursor used, and the distance and size between the electronic components 30, it is generally preferably about 10 to 200 μm, more preferably about 15 to 100 μm, and still more preferably about 20 to 70 μm.

In embodiment C1, a case will be described in which the electromagnetic wave shielding member 1 is fixed to the dicing table using a dicing tape, and is cut from the substrate 20 side. The method is suitable for the case where the solder balls are bonded to the outer main surface of the substrate 20. According to the electromagnetic wave shielding member 1 of embodiment C1, the root mean square height Rq of the surface layer of the electromagnetic wave shielding member 1 is set to the range of 0.05 μm or more and less than 0.3 μm, which is convenient for preventing the electromagnetic wave shielding member 1 from floating (partial poor adhesion) and peeling from the electronic component effectively even when the electromagnetic wave shielding member 1 side is fixed by a dicing tape in the singulation step, and an electronic component mounting substrate having good coating properties is provided.

< laminate for electromagnetic wave shielding >

As described with reference to fig. 4, the electromagnetic wave shielding laminate according to embodiment C1 includes two layers, i.e., the electromagnetic wave shielding member 2 and the releasable cushioning member 3. In embodiment C1, the electromagnetic wave shielding member 2 includes a single-layer conductive adhesive layer 6. The conductive adhesive layer 6 is bonded to the electronic component 30 or the substrate 20 through a thermocompression bonding step, and functions as the electromagnetic wave shielding layer 5.

(conductive adhesive layer)

Suitable examples and suitable contents of the curable compound are the same as those in embodiment a 1. Suitable examples of the thermoplastic resin and suitable examples of the adhesion-imparting resin are the same as those in embodiment a 1.

Further, examples of the conductive filler include a metal filler, conductive ceramic particles, and a mixture thereof, and specific examples thereof are the same as those in embodiment a 1. The silver content of the silver-plated copper is also preferably the same as in embodiment a 1. Further, in the case of the core-shell particles, the suitable range of the coating rate of the coating layer with respect to the core portion is also the same as that of embodiment a 1.

As the conductive filler, an electromagnetic wave absorbing filler can be used, and as a specific example, the same example as in embodiment a1 can be given.

Examples of the shape of the conductive filler used in the conductive adhesive layer include flake-like particles, dendrite-like particles, needle-like particles, plate-like particles, grape-like particles, fibrous particles, and spherical particles, and the root mean square height Rq tends to decrease when the proportion of the flake-like particles is increased and tends to increase when the proportion of the flake-like particles is decreased. From the viewpoint of adjusting the desired values of the root-mean-square height Rq and the root-mean-square slope Rdq, the conductive filler containing needle-like particles and/or dendritic particles is preferable.

The conductive fillers may be used alone or in combination. In the case of using the conductive filler in combination, from the viewpoint of obtaining a desired root mean square height Rq and providing an electromagnetic wave shielding member having high reliability, a combination of scaly particles and dendritic particles, a combination of scaly particles and acicular particles, and a combination of scaly particles, dendritic particles, and acicular particles are preferable. Particularly preferred is a combination of scaly particles and dendritic particles. Here, the flaky particles are preferably 0.2 μm or less in thickness.

The needle-like particles and/or dendritic particles are preferably 30% by mass or less with respect to 100% by mass of the conductive filler in the conductive adhesive layer. More preferably 0.1 to 20% by mass, still more preferably 1 to 20% by mass, and particularly preferably 3 to 16% by mass. The method for adjusting the root-mean-square height Rq to 0.05 μm or more and less than 0.3 μm is not particularly limited, and various methods can be used. For example, the root mean square height Rq can be easily adjusted by performing a pressing process on the surface layer of the electromagnetic wave shielding member and the surface layer of the conductive adhesive layer 6 in embodiment C1 in advance by a roller before laminating the buffer member, and then using a buffer member in which the root mean square height of the surface of the buffer member on the side to be bonded to the surface layer of the electromagnetic wave shielding member is a desired Rq.

The average particle diameter D50 of the needle-like particles is preferably 1 to 50 μm, more preferably 2 to 25 μm. More preferably 5 to 15 μm. The average particle diameter D50 of the dendritic particles is preferably in the range of 2 to 100. mu.m, more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. The average particle diameter D50 of the flaky particles is preferably 2 to 70 μm, more preferably 2 to 50 μm. More preferably 3 to 25 μm, and particularly preferably 5 to 15 μm.

By using the dendritic particles and/or acicular particles and the scaly particles in combination, the number of contact points between the conductive fillers can be increased, and the shielding property can be improved. Further, by using the dendritic particles and/or the acicular particles in combination, the contact area with the binder component can be increased, and an electromagnetic wave shielding member with high reliability can be provided.

The composition constituting the conductive adhesive layer may contain a colorant, a flame retardant, an inorganic additive, a lubricant, an antiblocking agent, and the like. Specific examples of these are the same as those in embodiment a 1.

After the coating liquid of the conductive adhesive layer is applied, the conductive adhesive layer is formed on the releasable substrate by drying. The drying step is preferably carried out by heating (for example, 80 ℃ C. to 120 ℃ C.). In order to adjust the root mean square height Rq of the electromagnetic wave shielding member, it is preferable to dry the electromagnetic wave shielding member at 25 ℃ (room temperature) and normal pressure for 1 to 17 minutes after the coating liquid is applied and before the heating and drying. The drying time at 25 ℃ C (room temperature) before the heat drying is more preferably 2 minutes to 14 minutes. The value of the root-mean-square height Rq can be adjusted by providing a process of drying at room temperature before heating and drying.

Next, the influence of the viscosity of the coating liquid and the drying time at 25 ℃ before heating and drying on the root-mean-square height Rq and the root-mean-square slope Rdq of the electromagnetic wave shielding member 1 will be described. The coating liquid is applied to form a conductive adhesive layer on a releasable substrate. The conductive adhesive layer including the solvent in the drying process can be obtained.

By setting the drying time at 25 ℃ to be long for the conductive adhesive layer during heating, the state in which the evaporation rate of the solvent is slow is intentionally extended, and the downward sinking of the binder resin precursor can be promoted. On the other hand, the drying time at 25 ℃ is set short to suppress downward sinking of the binder resin precursor, and the conductive filler is easily raised by performing heat drying at the above stage. In addition, foaming is likely to occur with evaporation of the solvent, and the surface tends to be cracked. The temperature of 25 ℃ is set as an example, and may be set as appropriate.

The solid content of the coating liquid is preferably 20% to 30%. In order to adjust the root mean square height Rq of the electromagnetic wave shielding member, it is preferable that the viscosity of the coating liquid measured by a B-type viscometer be in a range of 600MPa · s to 1800MPa · s. Further, in order to adjust the root mean square height Rq of the electromagnetic wave shielding member, it is preferable that the thixotropic index of the coating liquid is 1.2 to 1.5.

The values of the root-mean-square height Rq and the root-mean-square slope Rdq also vary depending on the viscosity of the coating liquid used for forming the conductive adhesive layer. The viscosity of the coating liquid is high, and the fluidity of the conductive filler tends to be suppressed. Therefore, when the viscosity is high, the conductive filler tends to be random without being oriented. On the other hand, when the viscosity is low, the scaly particles tend to be oriented so that the main surface of the scaly particles is approximately opposed to the substrate surface. When the drying time at 25 ℃ is shortened and the heating and drying are performed, surface cracks due to foaming tend to be increased when the viscosity is high, and the conductive filler tends to move in the longitudinal direction easily when the viscosity is low. Thus, the root mean square height Rq can be adjusted by adjusting the viscosity of the coating liquid and the drying time at 25 ℃.

The root-mean-square height Rq and root-mean-square slope Rdq of the electromagnetic wave shielding member 1 may be adjusted by the particle diameter of the dendritic particles and/or acicular particles. The influence of the particle diameter of the dendritic particles and/or acicular particles on the root-mean-square height Rq and root-mean-square slope Rdq of the electromagnetic wave shielding member 1 will be described. The coating liquid is applied to form the conductive adhesive layer 6 on the releasable substrate, whereby the conductive adhesive layer can be obtained while being dried. When the average particle diameter D50 of the dendritic particles, which is one type of the conductive filler, is small, the values of the root mean square height Rq and the root mean square slope Rdq tend to decrease, and conversely, when the average particle diameter D50 of the dendritic particles is large, the values of the root mean square height Rq and the root mean square slope Rdq tend to increase. In addition, the root mean square slope Rdq depends on the shape of the acicular particles. When the particle diameter D50 of the needle-like particles is large, Rdq becomes large. When the particle diameter D50 of the needle-like particles is small, Rdq becomes small.

The root mean square height Rq and the root mean square slope Rdq of the electromagnetic wave shielding member 1 can be adjusted by adjusting the addition amount ratio of the scale-like conductive filler to the needle-like and/or dendritic conductive filler in the composition of the electromagnetic wave shielding member 2 before thermocompression bonding, in addition to the adjustment method by the above-described process. The root-mean-square height Rq of the electromagnetic wave shielding member 1 can also be adjusted by the average particle diameter D50 and the average particle diameter D90 of the conductive filler.

In embodiment C1, since the electromagnetic wave shielding member 2 includes the single-layer conductive adhesive layer 6, the releasable cushioning member 3 is bonded to the conductive adhesive layer 6. The bonding method may be a method using lamination.

The releasable substrate is a substrate having releasability on one or both surfaces, and is a sheet having a tensile strain at break at 150 ℃ of less than 50%. Specific examples of the releasable substrate are the same as those in embodiment a 1.

The releasable cushioning member described in embodiment a1 can be cited.

[ embodiment C2]

Next, an example of an electronic component mounting board different from embodiment C1 will be described. The electronic component mounting substrate according to embodiment C2 differs from embodiment C1 in that the electromagnetic wave shielding member includes two electromagnetic wave shielding layers, and has the same basic configuration and manufacturing method as those of embodiment C1 except that the electromagnetic wave shielding member includes a single electromagnetic wave shielding layer. The basic configuration and manufacturing method are the same as those of embodiment a2, except that the electromagnetic wave shielding member of embodiment C is used instead of the electromagnetic wave shielding member of embodiment a, or the electromagnetic wave shielding member of embodiment a is used as described above. Duplicate descriptions are omitted as appropriate.

As shown in fig. 11, the electromagnetic wave shielding member according to embodiment C2 is formed using an electromagnetic wave shielding laminate 4a including an electromagnetic wave shielding member 2a and a releasable cushion member 3a, wherein the electromagnetic wave shielding member 2a is a conductive adhesive layer 6a including two layers, i.e., a first conductive adhesive layer 6a1 and a second conductive adhesive layer 6a 2. The electromagnetic wave shielding laminate 4a is thermocompression bonded to cover the substrate 20 on which the electronic component 30 is mounted with the electromagnetic wave shielding member including the first electromagnetic wave shielding layer and the second electromagnetic wave shielding layer. The upper second conductive adhesive layer 6a2 is manufactured by the same composition or steps as those of embodiment C1, and the lower first conductive adhesive layer 6a1 is not limited by the range of the root mean square height Rq and can be designed as required. For example, a layer using a filler such as fibrous particles or spherical particles as the conductive filler contained in the first conductive adhesive layer 6a1 can be used. The first conductive adhesive layer 6a1 may be an anisotropic conductive adhesive layer, and the second conductive adhesive layer 6a2 may be an isotropic conductive adhesive layer. In addition, a laminate of the electromagnetic wave reflection layer and the electromagnetic wave absorption layer is also preferable. Three or more electromagnetic wave shielding layers may be laminated.

According to the electronic component mounting substrate of embodiment C2, the same effects as those of embodiment C1 can be obtained by using the electromagnetic wave shielding member including the electromagnetic wave shielding layer having two layers. In addition, by laminating two electromagnetic wave shielding layers, the degree of freedom in designing each layer can be increased, and thus there is an advantage in that an electromagnetic wave shielding member corresponding to the demand can be easily provided.

[ embodiment C3]

The electronic component mounting substrate according to embodiment C3 is different from embodiment C1 in that the electromagnetic wave shielding member includes a laminate of an electromagnetic wave shielding layer and a hard coat layer, and has the same basic configuration and manufacturing method as those of the electromagnetic wave shielding member including a single electromagnetic wave shielding layer.

As shown in fig. 12, the electromagnetic wave shielding member according to embodiment C3 is formed using an electromagnetic wave shielding laminate 4b including an electromagnetic wave shielding member 2b and a releasable cushioning member 3b, the electromagnetic wave shielding member 2b being a laminate of a single conductive adhesive layer 6b and an insulating resin layer 7 b. By thermocompression bonding the electromagnetic wave shielding laminate 4b, an electromagnetic wave shielding member including an electromagnetic wave shielding layer formed of the conductive adhesive layer 6b and a hard coat layer formed of the insulating resin layer 7b can be obtained on a substrate on which an electronic component is mounted. In the electromagnetic wave shielding member according to embodiment C3, the root mean square height Rq as measured from the hard coat layer side is 0.05 μm or more but less than 0.3 μm.

The insulating resin layer 7b is a layer formed of a resin composition containing a binder resin precursor and an inorganic filler. The binder resin precursor contains at least a thermo-softening resin. Examples and suitable examples of the binder resin precursor are the same as those of the composition of the conductive adhesive layer of the electromagnetic wave shielding member described in embodiment a 1. The binder resin precursors of the conductive adhesive layer and the insulating resin layer may be the same or different.

The inorganic filler does not have conductivity unlike the conductive adhesive layer of embodiment C1, but the preferable properties of the inorganic filler, such as shape, amount of blending, D50, D90, and the like, are the same as those of the conductive filler. Examples of the inorganic filler include: silica (fused silica, crystalline silica, amorphous silica), beryllium oxide, alumina, magnesium hydroxide, barium sulfate, calcium carbonate, titanium oxide, zinc oxide, antimony trioxide, antimony oxide, magnesium oxide, talc, kaolinite, mica, basic magnesium carbonate, sericite, montmorillonite, kaolinite, bentonite, kaolinite, clay, hydrotalcite, wollastonite, xonotlite, silicon nitride, boron nitride, aluminum nitride, calcium hydrogen phosphate, inorganic compounds such as calcium phosphate, glass flake, hydrated glass, calcium titanate, sepiolite, magnesium sulfate, aluminum hydroxide, zirconium hydroxide, barium hydroxide, calcium oxide, tin oxide, aluminum oxide, zirconium oxide, molybdenum oxide, nickel oxide, zinc carbonate, magnesium carbonate, barium carbonate, zinc borate, aluminum borate, calcium silicate, silicon carbide, titanium carbide, diamond, graphite, and graphene.

By using a thermally conductive filler as the inorganic filler, the hard coat layer can also function as a thermally conductive layer. May be used as a hard coat layer, a heat conductive layer (e.g., a heat dissipation layer), or a layer having functions of both, depending on the use.

Suitable examples of the preferable formulation components and formulation amounts of the binder resin precursor for the insulating resin layer are the same as those of the conductive adhesive layer of embodiment C1. The preferred shape, the preferred average particle diameter D50, and the like of the inorganic filler used in the insulating resin layer are the same as those of the conductive filler of embodiment C1. The additive applicable to the heat-softening resin composition and the heat-softening resin composition layer may be the additive described in embodiment 1C.

According to the electronic component mounting substrate of embodiment C1, by using the electromagnetic wave shielding member having the hard coat layer, it is possible to provide an electromagnetic wave shielding member having more excellent durability because the electromagnetic wave shielding layer is coated with the hard coat layer in addition to the effects described in embodiment C1.

[ embodiment C4, embodiment C5]

The electronic component mounting boards according to embodiments C4 and C5 can be referred to the description of embodiments a4 and a5, except that the electromagnetic wave shielding member according to embodiment C is used instead of the electromagnetic wave shielding member according to embodiment a.

< modification example >

Next, a modified example of the electronic component mounting board and the like of the present embodiment will be described. However, the present invention is not limited to the above-described embodiments and modifications, and other embodiments may be made within the scope of the present invention as long as they are consistent with the spirit of the present invention. The embodiments and the modifications may be combined with each other as appropriate.

In embodiment a4, embodiment a5, embodiment B4, embodiment B5, embodiment C4, and embodiment C5, an example of an electromagnetic wave shielding laminate using a laminate including an insulating adhesive layer, a conductive adhesive layer, and a mold-releasable buffer member is described, but it may be produced as follows. That is, as shown in fig. 16A, on the substrate 20 on which the plurality of electronic components 30 are mounted, first, as shown in fig. 16B, the insulating coating layer 9e is formed. The insulating coating layer 9e is obtained by hot-pressing a sheet including an insulating adhesive layer. Thereafter, an electromagnetic wave shielding laminate 4e using a laminate including the conductive adhesive layer 6e and the releasable cushioning member 3e is used to form an electromagnetic wave shielding layer 5e (fig. 16C and 16D). Through these steps, the electronic component mounting substrate 55 on which the electromagnetic wave shielding member is formed can be obtained. In addition, the insulating coating layer 9e may be formed by a method of applying a solution resin and a method of spraying a solution resin, instead of a method of hot-pressing a sheet.

In the above-described embodiment, the description has been given taking the electronic component as an example of the component, but the present invention can be applied to all components that are intended to be distant from electromagnetic waves. The shape of the component is not limited to a rectangular shape, and includes a component having an R-shaped corner, a component having an acute angle formed between the upper surface of the component and the side surface, and a component having an obtuse angle formed between the upper surface of the component and the side surface. In addition, the outer surface of a component or an electronic component having a concave-convex shape on the upper surface may be a curved surface such as a sphere. In the above embodiment, the half-cut groove 25 (see fig. 2) is formed in the substrate 20, but the half-cut groove 25 is not essential, and the electromagnetic wave shielding member may be placed on and covered with a flat substrate. The electronic component mounting board of the present invention includes, for example, the following cases: an electronic component mounting substrate on which electronic components are mounted, which is obtained by dicing the substrate 20 into pieces, is mounted on another holding base material or the like.

The electromagnetic wave shielding laminate is not limited to the laminate of the above embodiment. For example, the supporting substrate may be laminated on the releasable cushioning member. By stacking the support substrates, contamination of the device during thermocompression bonding can be easily prevented. In addition, the support substrate has an advantage that the step of adhering the electromagnetic wave shielding laminate is easy. The electronic components may be mounted on not only one surface of the substrate but also both surfaces thereof, and the electromagnetic wave shielding members may be formed on the respective electronic components.

The electronic component mounting substrate according to the present embodiment is excellent in covering property with respect to the uneven structure, and therefore can be suitably applied to various electronic apparatuses such as a personal computer, a mobile device, and a digital camera.

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, "part" means "part by mass" and "%" means "% by mass". The values described in the present invention are obtained by the following method.

[ [ embodiment A ] ]

(test substrate 1)

A substrate was prepared in which electronic components (1cm × 1cm) sealed by molding were mounted in an array of 5 × 5 pieces on a substrate made of epoxy glass. The thickness of the substrate was 0.3mm, and the mold seal thickness, i.e., the height (part height) H from the upper surface of the substrate to the top surface of the mold seal material was 0.7 mm. Thereafter, a test substrate was obtained by half-cutting the test substrate following the groove serving as the gap between the components (see fig. 17). The half-cut groove depth was set to 0.8mm (the groove depth of the substrate 20 was 0.1mm), and the half-cut groove width was set to 200 μm.

(test substrate 2, test substrate 3)

The test substrate 2 was produced in the same manner as the test substrate 1 except that the half-cut groove width was changed to 150 μm. The test substrate 3 was produced in the same manner as the test substrate except that the half-cut groove width was changed to 150 μm and the groove depth was changed to 1000 μm.

The materials used in the examples are shown below.

Precursor of binder resin

Resin 1: polycarbonate resin (manufactured by Toyochem chemical Co., Ltd.)

Resin 2: phenoxy resin (manufactured by Toyo chemical Co., Ltd.)

Curable compound 1: DEKENAR (DENACOL) EX830 (Rice-Scale-growing (Nagase ChemteX) corporation)

Curable compound 2: JeRYX8000 (manufactured by Mitsubishi Chemical Co., Ltd.)

Curable compound 3: JeR157S70 (manufactured by Mitsubishi chemical corporation)

Hardening accelerator: PZ-33 (manufactured by Nippon catalyst Co., Ltd.)

Conductive filler 1: scale-like silver (average particle diameter D50: 11 μm) (manufactured by Futian Metal Co., Ltd.)

Conductive filler 2: needle-like silver-plated copper (average particle diameter D50: 7.5 μm) (manufactured by Futian metals Co., Ltd.)

Additive 1: BYK322 (manufactured by BYK Chemie Co., Ltd.)

Additive 2: BYK337 (manufactured by Bick chemical Co., Ltd.)

Example A1

(preparation of resin composition for conductive adhesive layer)

As shown in table 1, 20 parts (solid content) of resin 1 (polycarbonate resin), 80 parts (solid content) of resin 4 (phenoxy resin), 20 parts of curable compound 1 (epoxy resin), 15 parts of curable compound 2 (epoxy resin), 10 parts of curable compound 3 (epoxy resin), and 320 parts of conductive filler 1 (scaly silver), 5 parts of conductive filler 2 (needle-like silver-plated copper), 1 part of curing accelerator, 0.4 part of additive 1 were added to a vessel, and toluene was added so that the solid content concentration became 25 mass%: a mixed solvent of isopropyl alcohol (mass ratio 2: 1) was stirred with a disperser for 10 minutes, thereby obtaining a resin composition for forming a conductive adhesive layer.

(production of electromagnetic wave shielding laminate)

The resin composition was applied to a releasable substrate using a doctor blade so that the dry thickness thereof became 50 μm. Then, the mixture was dried at 25 ℃ for 14 minutes at room temperature and then dried at 100 ℃ for 2 minutes, thereby obtaining an electromagnetic wave shielding member (conductive adhesive layer). Next, a releasable buffer member (CR 1040) having a layer structure (thickness 150 μm) in which polymethylpentene was sandwiched between both surfaces of the soft resin layer was prepared, and laminated with an electromagnetic wave shielding member, thereby obtaining an electromagnetic wave shielding laminate of example a1 on a releasable substrate.

Example A2-example A5, reference example A1

A resin composition for a conductive adhesive layer and an electromagnetic wave shielding laminate were obtained in the same manner as in example a1, except that the composition was changed to the composition shown in table 1.

Example A6-example A10, reference example A2

Toluene was added so that the solid content concentration became 29 mass% except that the composition was changed as shown in table 1: a resin composition for a conductive adhesive layer and an electromagnetic wave shielding laminate were obtained in the same manner as in example a1, except for the mixed solvent of isopropyl alcohol (mass ratio 2: 1).

< kurtosis >

Electromagnetic wave shielding laminates of examples a1 to a10, reference examples a1 and a2 were prepared, and the laminates were placed on an FR4 substrate having a thickness of 300 μm and were thermally pressed at 170 ℃ for 5 minutes from the side of the releasable buffer member toward the surface under a pressure of 8 MPa. Thereafter, the releasable cushioning member was peeled off, and the resultant was heated at 180 ℃ for 2 hours. Thereafter, the releasable cushioning member was peeled off to obtain a test piece on which the electromagnetic wave shielding member was formed.

In the test piece, the surface of the electromagnetic wave shielding member from which the releasable cushioning member was peeled was subjected to a metal sputtering treatment. The metal sputtering treatment conditions were 0.5 minute sputtering using a sputtering apparatus "Smart Coater (manufactured by japan electronics ltd.) using gold as a target and setting the distance between the target and the sample surface to 2 cm. The metal sputtering surface of the obtained sample was treated according to JISB 0601: 2001, the kurtosis was determined using a laser microscope (VK-X100, manufactured by Keyence corporation). In the measurement condition, the surface shape was obtained with the measurement magnification set to 1000 times in the shape measurement mode. For the obtained surface shape image, in the surface roughness measurement by the analysis application software, the kurtosis was measured by selecting the entire region and setting the λ s profile filter to 2.5 μm and the λ c profile filter to 0.8 mm. The measurement was performed at different 5 points, and the average of the measured values was taken as the value of kurtosis.

In the measurement of the kurtosis of the electromagnetic wave shielding member, when the electromagnetic wave shielding member actually covering the electronic component mounting substrate is measured, the electromagnetic wave shielding member covering the electronic component mounting substrate may be directly measured.

< viscosity and thixotropic index of coating liquid >

The obtained conductive resin composition was allowed to stand in a water bath at 25 ℃ for 30 minutes, and then the viscosity at a rotation speed of 6rpm (v1) and the viscosity at a rotation speed of 60rpm (v2) were measured by a "B-type viscometer" (manufactured by east-Shaw industries, Ltd.). The value obtained by dividing (v1) by (v2) was taken as the thixotropic index.

< evaluation of releasability of half-cut groove of releasable cushion member after thermocompression bonding >

The electromagnetic wave shielding laminates of the examples and the reference examples were each thermocompression bonded to each of the test substrates 1 to 3 under conditions of 8MPa and 170 ℃ for 5 minutes, and then the releasable buffer member was peeled off by hand. The number of residues of the mold release cushioning member remaining after the groove in the gap between the electronic components was broken was visually checked. The evaluation criteria are as follows.

+++: no residue was observed.

++: the number of residues is more than one and less than three.

+: the number of residues is more than three and less than five.

NG: the residue is in a state of five or more, or the residue is left in the whole tank.

< Steel wool resistance >

The electromagnetic wave shielding laminates of the examples and the reference examples, which were cut into 5cm × 15cm, were placed on polyimide films (Kapton 500H, manufactured by dony dupont) having a thickness of 125 μm, hot-pressed at 180 ℃ for 10 minutes under 2MPa, and then cured at 180 ℃ for 2 hours, thereby obtaining test substrates. Thereafter, the releasable cushioning member is peeled off. Then, the electromagnetic wave shielding member was set in a vibration-type abrasion Tester (manufactured by Tester Sangyo Co.) and the number of times of vibration until the polyimide film was exposed by abrasion of the electromagnetic wave shielding member was determined under the conditions of a load of 200gf, a stroke of 120mm, and a reciprocating speed of 30 times/min. The evaluation criteria are as follows.

+++: more than 20,000 times.

++: the number of the preparation is more than 10,000 and less than 20,000.

+: more than 5,000 times and less than 10,000 times (practical level).

NG: less than 5,000 times.

The evaluation results of examples a1 to a10 and reference examples a1 and a2 are shown in table 1.

[ Table 1]

As shown in the examples in table 1, the steel wool resistance of the electronic component mounting board using the electromagnetic wave shielding member of reference example a1 having a kurtosis of less than 1 did not reach an acceptable level. On the other hand, it was confirmed that the electromagnetic wave shielding members of the electronic component mounting board of the present invention all reached a satisfactory level and were excellent in steel wool resistance. In addition, the electromagnetic wave shielding member of reference example a2 in which the kurtosis exceeded 8 did not reach an acceptable level of peelability of the groove portion. In contrast, it was confirmed that the releasability of the groove portion of the releasable cushioning member after the thermocompression bonding of the electromagnetic wave shielding member of the electronic component mounting substrate of the present invention was excellent.

[ [ embodiment B ] ]

(test substrate)

The test substrate of embodiment B was obtained by the same production method as the test substrate 1 of embodiment a.

The materials used in the examples are shown below.

Precursor of binder resin

Resin 1: urethane resin (manufactured by Toyo chemical Co., Ltd.)

Resin 2: polycarbonate resin (manufactured by Toyo chemical Co., Ltd.)

Resin 3: styrene elastomer resin (manufactured by Toyo chemical Co., Ltd.)

Resin 4: phenoxy resin (manufactured by Toyo chemical Co., Ltd.)

Curable compound 1: de Koonaire (Denacol) EX830 (tradename, or other name

Curable compound 2: jERYX8000 (manufactured by Mitsubishi chemical corporation)

Curable compound 3: JeR157S70 (manufactured by Mitsubishi chemical corporation)

Hardening accelerator: PZ-33 (manufactured by Nippon catalyst Co., Ltd.)

Conductive filler

Additives

Additive 1: BYK322 (manufactured by Bick chemical Co., Ltd.)

Additive 2: BYK337 (manufactured by Bick chemical Co., Ltd.)

Example B1

(preparation of resin composition for conductive adhesive layer)

As shown in table 2, 70 parts (solid content) of resin 1 (urethane resin), 30 parts (solid content) of resin 2 (polycarbonate resin), 30 parts of curable compound 1 (epoxy resin), 15 parts of curable compound 2 (epoxy resin) as a binder resin precursor, and 280 parts of conductive filler 1 (scaly silver), 50 parts of conductive filler 2 (needle-like silver-plated copper), 1 part of curing accelerator, 0.4 part of additive 1 were added to a vessel, and toluene was added so that the solid content concentration became 35 mass%: a mixed solvent of isopropyl alcohol (mass ratio 2: 1) was stirred with a disperser for 10 minutes, thereby obtaining a resin composition for forming a conductive adhesive layer.

(production of electromagnetic wave shielding laminate)

The resin composition was applied to a releasable substrate using a doctor blade so that the dry thickness thereof became 50 μm. Then, the mixture was dried at 25 ℃ for 12 minutes at room temperature and then dried at 100 ℃ for 2 minutes, thereby obtaining an electromagnetic wave shielding member (conductive adhesive layer). Subsequently, a releasable buffer member (CR 1040) having a layer structure (thickness 150 μm) in which polymethylpentene was sandwiched between both surfaces of the soft resin layer was prepared, and the electromagnetic wave shielding member was laminated thereon, thereby obtaining the electromagnetic wave shielding laminate of example B1 on the releasable substrate.

(preparation of test piece of electronic component mounting substrate)

Then, the electromagnetic wave shielding laminate on the releasable substrate was cut into pieces of 10cm × 10cm, and after the releasable substrate was peeled off, the electromagnetic wave shielding laminate was placed on the test substrate and temporarily adhered thereto so that the side of the conductive adhesive layer of the electromagnetic wave shielding laminate was in contact therewith (see fig. 17). The substrate surface was thermocompression bonded from above the electromagnetic wave shielding laminate for 2 hours under conditions of 2MPa and 180 ℃. After thermocompression bonding, the releasable buffer member was peeled off, thereby obtaining an electronic component mounting substrate (test piece) of example 1 coated with the electromagnetic wave shielding member.

Example B2 to example B19, reference example B1, reference example B2

Resin compositions for conductive adhesive layers, electromagnetic wave shielding laminates, and test pieces for electronic component mounting substrates of the examples and reference examples were obtained in the same manner as in example B1, except that the compositions described in tables 2 and 3 were changed.

< modulus of elasticity at indentation >

Electromagnetic wave shielding laminates of examples B1 to B19, reference examples B1 and reference example B2 were prepared, and the laminates were placed on an FR4 substrate having a thickness of 300 μm and heated from the side of the releasable buffer member toward the surface at 180 ℃ under a pressure of 2MPa for 2 hours. Thereafter, the releasable buffer member was peeled off to obtain a test piece of the FR4 substrate on which the electromagnetic wave shielding member was formed. Then, the indentation elastic modulus was measured from the side on which the releasable cushioning member was laminated by the following method.

That is, the measurement was performed using a Fichhol oscilloscope (Fischer scope) H100C (manufactured by Fischer Instruments) type durometer with a Vickers indenter (diamond indenter with a spherical tip of 100. phi.) in a thermostatic chamber at 25 ℃ with a test force of 0.3N, a retention time of the test force of 20 seconds, and a time required for addition of the test force of 5 seconds. The indentation elastic modulus was determined by averaging values obtained by repeating measurements at 5 points randomly on the same film surface of the electromagnetic wave shielding member.

In the measurement of the press-fitting elastic modulus of the electromagnetic wave shielding member, the electromagnetic wave shielding member actually covered on the electronic component mounting substrate may be measured. In this case, the measurement is performed by bringing the vickers indenter into direct contact with the electromagnetic wave shielding member coated on the electronic component substrate. The electromagnetic wave shielding member actually covered on the electronic component mounting substrate can be measured in the same manner as in the later-described kurtosis and water contact angle.

< kurtosis >

A test substrate of FR4 substrate was obtained by the same method as that described in embodiment a, and the kurtosis was determined by the same method.

< Water contact Angle >

For a test piece of FR4 substrate produced in the same manner as the measurement sample of indentation elastic modulus, the water contact angle of the electromagnetic wave shielding member was measured with respect to the surface of the electromagnetic wave shielding layer using "automatic contact angle meter DM-501/analysis software FAMAS" manufactured by covariant interface science (stock). The measurement was performed by a liquid adaptation method.

< determination of Ma hardness >

Test pieces of the electronic component mounting substrates of the examples and the reference examples were prepared, and the mohs hardness was measured by a fisher oscilloscope (fischer scope) H100C (manufactured by fisher instruments) type durometer in accordance with ISO 14577-1. The measurement was performed on the upper surface of the electronic component 30 by using a vickers indenter (a diamond indenter having a spherical tip with a diameter of 100 mm) in a thermostatic chamber at 25 ℃ under conditions of a test force of 0.3N, a holding time of the test force of 20 seconds, and a time required for applying the test force of 5 seconds. The average value of the values obtained by repeating the measurement at 10 spots on the same surface of the hard film was determined as the March hardness. Further, the test force is adjusted in accordance with the thickness of the electromagnetic wave shielding layer. Specifically, the test force is adjusted so that the maximum press-fitting depth is about one tenth of the thickness of the electromagnetic wave shielding member.

< viscosity and thixotropic index of coating liquid >

The viscosity at 6rpm (v1) and the viscosity at 60rpm (v2) were measured by the same method as that described in embodiment A. In addition, the thixotropic index was determined by the same method.

< Burr at full cut >

The electromagnetic wave shielding laminates of the examples and the reference examples were thermally pressed against the test substrate (substrate having electronic components mounted in a5 × 5 array) under conditions of 8Mpa and 170 ℃ for 5 minutes, and then the releasable cushioning member was peeled off by hand. Thereafter, curing was performed at 180 ℃ for 2 hours, thereby obtaining a test sample coated with an electromagnetic wave shielding member. The obtained test sample was evaluated for burr generation in the case of the singulation step (full dicing) using a laser microscope according to the following criteria.

+++: no burr was confirmed.

++: in 25 singulated electronic parts, the generation of burrs was less than two.

+: in 25 singulated electronic parts, the number of burrs generated was two or more and less than five.

NG: in 25 singulated electronic parts, the generation of burrs was five or more.

< tape adhesion >

The electromagnetic wave shielding laminates of the examples and the reference examples, which were cut into 5cm × 5cm, were each placed on an FR4 substrate having a thickness of 300 μm, hot-pressed at 170 ℃ for 5 minutes under 8MPa, and then cured at 180 ℃ for 2 hours, thereby obtaining test substrates. Subsequently, the releasable cushioning member is peeled off. Thereafter, the test substrate obtained was subjected to a pressure cooker test at 130 ℃ and a humidity of 85% and a pressure of 0.23 MPa. The test time was 96 hours, and an adhesive tape having a width of 18mm manufactured by Nichiban was used. Further, according to JISK5600, 25 grids with a spacing of 1mm are fabricated on the electromagnetic wave shielding member using a transverse guide. Thereafter, the adhesive tape was pressed against the grid portion of the electromagnetic wave shielding member, and the end portion of the tape was peeled off at once at an angle of 45 ° to perform a tape adhesion test. The state of the grid of the electromagnetic wave shielding member (transverse survival rate) is determined by the following criteria.

+++: indicating a survival rate of 25/25.

++: indicating a survival rate of 24/25.

+: indicating a survival rate of 23/25.

NG: the remaining rate is less than 23/25.

The electromagnetic wave shielding laminates of the examples and the reference examples were each thermally compression bonded to the test substrate (half-cut groove depth 800 μm, groove width 200 μm) at 8MPa and 170 ℃ for 5 minutes, and then the releasable buffer member was peeled off by hand. The number of residues of the mold release cushioning member remaining after the groove in the gap between the electronic components was broken was visually checked. The evaluation criteria are as follows.

+++: no residue was observed.

++: the number of residues is more than one and less than three.

+: the number of residues is more than three and less than five.

< Steel wool resistance >

A test substrate was obtained by the same method as that described in embodiment a, and the steel wool resistance was evaluated by the same measurement method. The evaluation criterion was also set to be the same.

The evaluation results of examples B1 to B19 and reference examples B1 and B2 are shown in table 2 and table 3.

[ Table 2]

[ Table 3]

As shown in the examples in tables 2 and 3, the burr at the time of full-cutting of the electronic component mounting substrate using the electromagnetic wave shielding member of reference example B1 in which the press-fitting elastic modulus was less than 1 did not reach the acceptable level. On the other hand, it was confirmed that the electromagnetic wave shielding members of the electronic component mounting board of the present invention all reached a satisfactory level and the generation of burrs was suppressed. The tape adhesiveness after the PCT test using the electromagnetic wave shielding member of reference example B2 in which the elastic modulus exceeded 10GPa was not satisfactory. On the other hand, it was confirmed that the electromagnetic wave shielding member of the electronic component mounting board of the present invention has satisfactory tape adhesiveness after the PCT test and is excellent in PCT resistance.

Fig. 22 shows an image of a side surface of the electronic component mounting substrate after singulation according to example B3, which is observed with a microscope. As shown in the figure, no burr is seen. On the other hand, fig. 23 shows an image of a side surface of the electronic component mounting substrate after singulation in example B1 observed with a microscope. As shown in the figure, the generation of burrs can be seen.

[ [ embodiment C ] ]

(test substrate 1)

A test substrate was obtained by the same method as the method for producing the test substrate 1 of embodiment a.

The materials used in the examples are shown below.

Precursor of binder resin

Thermosetting resin 1: polycarbonate resin (manufactured by Toyo chemical Co., Ltd.)

Thermosetting resin 2: phenoxy resin (manufactured by Toyo chemical Co., Ltd.)

Curable compound 1: de Koonaire (Denacol) EX830 (tradename, or other name

Curable compound 2: jERYX8000 (manufactured by Mitsubishi chemical corporation)

Curable compound 3: JeR157S70 (manufactured by Mitsubishi chemical corporation)

Hardening accelerator: PZ-33

Conductive filler 1: scale-like silver (average particle diameter D50: 9.5 μm, D90 ═ 19 μm, thickness 0.1 μm)

Conductive filler 2: dendritic silver-plated copper (average particle diameter D50: 7.1 μm, D90 ═ 15.1 μm)

Additive 1: BYK337

[ example C1]

(preparation of resin composition for conductive adhesive layer)

As shown in table 4, 20 parts (solid content) of thermosetting resin 1 (polycarbonate resin), 80 parts (solid content) of thermosetting resin 2 (phenoxy resin), 20 parts of curable compound 1 (epoxy resin), 15 parts of curable compound 2 (epoxy resin), 10 parts of curable compound 3 (epoxy resin), and 365 parts of conductive filler 1 (scaly silver), 5 parts of conductive filler 2 (dendritic silver-plated copper), 1 part of a curing accelerator were added to a container, and toluene was added so that the solid content concentration became 23 mass%: a mixed solvent of isopropyl alcohol (mass ratio 2: 1) was stirred with a disperser for 10 minutes, thereby obtaining a resin composition for forming a conductive adhesive layer.

(production of electromagnetic wave shielding laminate)

An electromagnetic wave shielding laminate of example C1 was obtained in the same manner as in embodiment a.

(preparation of test piece of electronic component mounting substrate)

Then, the electromagnetic wave shielding laminate on the releasable substrate was cut into pieces of 10cm × 10cm, and after the releasable substrate was peeled off, the electromagnetic wave shielding laminate was placed on the test substrate and temporarily adhered thereto so that the side of the conductive adhesive layer of the electromagnetic wave shielding laminate was in contact therewith (see fig. 17). The substrate surface was thermocompression bonded from above the electromagnetic wave shielding laminate for 2 hours under conditions of 2MPa and 180 ℃. After thermocompression bonding, the releasable buffer member was peeled off, thereby obtaining an electronic component mounting substrate (test piece) of example C1 in which the electromagnetic wave shielding member was coated.

Example C2 to example C9 and reference example C1

A resin composition for a conductive adhesive layer and an electromagnetic wave shielding laminate were obtained in the same manner as in example C1, except that the composition was changed to the composition shown in table 4.

< root mean square height Rq >

The electromagnetic wave shielding laminates of examples C1 to C9 and reference example C1 were prepared, mounted on FR4 substrates 300 μm thick, and subjected to thermocompression bonding at 170 ℃ for 5 minutes from the side of the releasable buffer member toward the surface under 8 MPa. Thereafter, the releasable buffer member was peeled off and heated at 180 ℃ for 2 hours to obtain a test piece on which an electromagnetic wave shielding member was formed.

In the test piece, the surface of the electromagnetic wave shielding member from which the releasable cushioning member was peeled was subjected to a metal sputtering treatment. The metal sputtering treatment conditions were 0.5 minute sputtering using a sputtering apparatus "Smart Coater (manufactured by japan electronics ltd.) using gold as a target and setting the distance between the target and the sample surface to 2 cm. The metal sputtering surface of the obtained sample was treated according to JISB 0601: 2001, the root mean square height Rq was obtained using a laser microscope (VK-X100, manufactured by keyins corporation). In the measurement condition, the surface shape was obtained with the measurement magnification set to 1000 times in the shape measurement mode. For the obtained surface shape image, in the surface roughness measurement by the analysis application software, the root mean square height Rq was measured by selecting the entire region and setting the λ s profile filter to 2.5 μm and the λ c profile filter to 0.8 mm. The measurement was performed at different 5 points, and the average of the measured values was taken as the value of the root mean square height Rq.

In the measurement of the root mean square height Rq of the electromagnetic wave shielding member, when the electromagnetic wave shielding member actually covered on the electronic component mounting substrate is measured, the electromagnetic wave shielding member covered on the electronic component substrate may be directly measured.

< root mean square slope Rdq >

Using the surface shape image obtained in the measurement of Rq, in the line roughness measurement by the analysis application software, 20 two-dot lines were uniformly drawn in the entire image, and the root mean square slope Rdq was measured with the λ 0026s profile curve filter set to 2.5 μm and the λ c profile curve filter set to 0.8 mm. The measurements were performed at different 5 points, and the average of the measured values was taken as the value of the root mean square slope Rdq.

< Water contact Angle >

The electromagnetic wave shielding laminates of examples and reference examples were prepared, and the test piece of FR4 substrate having a thickness of 300 μm and produced in the same manner as the test sample for press-fitting the elastic modulus was placed thereon, and heated from the side of the releasable buffer member toward the surface at 180 ℃ under a pressure of 2MPa for 2 hours. Thereafter, the releasable buffer member was peeled off to obtain a test piece of the FR4 substrate on which the electromagnetic wave shielding member was formed. Then, the water contact angle was measured from the side on which the releasable cushioning member was laminated by the following method. That is, the water contact angle of the electromagnetic wave shielding member was measured with respect to the surface of the electromagnetic wave shielding layer using "automatic contact angle meter DM-501/analysis software FAMAS" manufactured by covariant interface science (stock). The measurement was performed by a liquid adaptation method.

< viscosity and thixotropic index of coating liquid >

< tape coating >

The electromagnetic wave shielding laminates of the examples and the reference examples, which were cut into 5cm × 5cm, were each placed on an FR4 substrate having a thickness of 300 μm, hot-pressed at 170 ℃ for 5 minutes under 8MPa, and then cured at 180 ℃ for 2 hours, thereby obtaining test substrates. Subsequently, the releasable cushioning member is peeled off. Then, with respect to the obtained test substrate, the electromagnetic wave shielding member and a dicing tape (UHP-110AT (Ultraviolet (UV) type, Polyethylene terephthalate (PET) as a base material, and 110 μm in total thickness (including 10 μm in thickness of an adhesive layer)) were cut from the outer surface of the substrate 20 to singulate the electronic component mounting substrate. After singulation, the dicing tape was peeled off from the electromagnetic wave shielding member, and the state of the electromagnetic wave shielding member was observed with an optical microscope (magnification of 200 times) and evaluated according to the following criteria.

+++: the appearance is not abnormal.

++: at each 1cm²The electromagnetic wave shielding member (2) generates one to two floats having a diameter of 0.5mm or less.

+: at each 1cm²The electromagnetic wave shielding member of (2) generates three to four buoyages having a diameter of 0.5mm or less.

NG: at each 1cm²The electromagnetic wave shielding member according to (1) generates a float and a peel having a diameter exceeding 0.5mm, or generates five or more floats having a diameter of 0.5mm or less.

< evaluation of antifouling Property >

The electromagnetic wave shielding laminates of the examples and the reference examples, which were cut into 5cm × 15cm, were placed on polyimide films (Kapton 500H, manufactured by dony dupont) having a thickness of 125 μm, hot-pressed at 180 ℃ for 10 minutes under 2MPa, and then cured at 180 ℃ for 2 hours, thereby obtaining test substrates. Thereafter, the releasable cushioning member is peeled off. N-octanoic acid as a pseudo flux is applied to the top surface of the electromagnetic wave shielding member. Thereafter, the substrate was immersed in a cleaning solution in which dioxolane and isopropyl alcohol were mixed at 8/2, and ultrasonic cleaning was performed. After cleaning, the antifouling property was evaluated using an optical microscope (magnification: 200 times). The evaluation criteria are as follows.

+++: after 3 minutes of washing, there was no residue.

++: after 5 minutes of washing, there was no residue.

+: after 5 minutes of washing, at 1cm each²The surface of the electromagnetic wave shielding member (2) has residues at 1 to 2 points.

NG: after 5 minutes of washing, at 1cm each²More than 2 residues are left on the surface of the electromagnetic wave shielding member.

< Cold-Heat cycle test >

An electronic component mounting substrate (test piece) in which the test substrate shown in fig. 15 was coated with the electronic component mounting substrate (test piece) of example C1 was prepared, and the initial connection resistance value between both top surfaces (arrows in fig. 24) of the electronic component coated with the electromagnetic wave shielding member 1 was measured using a BSP probe of "Loresta (Loresta) GP" manufactured by Mitsubishi Chemical analysis technique (Mitsubishi Chemical analysis). Then, a cold-hot shock device ("TSE-11-A", manufactured by Espekey (Espec)) was put into operation, and the temperature of the solar cell was exposed to high temperature: 125 ℃, 15 min, low temperature solarization: 1000 alternate exposures were carried out at-50 ℃ for 15 minutes of exposure. Thereafter, the connection resistance value of the sample was measured in the same manner as in the initial stage.

The evaluation criteria for the cooling-heating cycle reliability are as follows. The measurement was performed at 3, and the average value was taken as the measurement value.

In the case where an insulating layer such as a hard coat layer is laminated on the outermost surface, the same test as described above is performed by removing the measurement portion of the insulating layer after the cooling-heating cycle test to expose the electromagnetic wave shielding layer 5. In this case, the measurement site of the insulating layer is removed by the same method as described above in another part of the same sample, and then the connection resistance value of the electromagnetic wave-shielding layer 5 before the cold-heat cycle test is determined.

+++: the value of (the connection resistance value after the alternate exposure)/(the initial connection resistance value) was less than 1.5, and was extremely good.

++: the (connection resistance value after alternate exposure)/(initial connection resistance value) was 1.5 or more and less than 3.0, which was good.

+: the (connection resistance value after alternate exposure)/(initial connection resistance value) is 3.0 or more and less than 5.0, and is practical.

NG: (the connection resistance value after the alternate exposure)/(the initial connection resistance value) is 5.0 or more.

The evaluation results of examples C1 to C9 and reference example C1 are shown in Table 4.

[ Table 4]

As shown in the example of table 4, the cooling-heating cycle test of the electronic component mounting substrate using the electromagnetic wave shielding member of reference example 1 having the root mean square height Rq of 0.3 or more did not reach the acceptable level. On the other hand, it was confirmed that the electromagnetic wave shielding members of the electronic component mounting substrate of the present invention all reached a satisfactory level and were excellent in covering property under severe conditions of the cold-heat cycle test. In addition, it has been confirmed that in the singulation step, coating defects such as floating and peeling can be effectively prevented in the electromagnetic wave shielding member. In addition, it was confirmed that the electromagnetic wave shielding member of the electronic component mounting substrate of the present invention is excellent in antifouling property.

The present application claims priority based on japanese application laid-open at 18.12.2018-.

Description of the symbols

1: electromagnetic wave shielding member

2: electromagnetic wave shielding member

3: demouldable buffering member

4: laminate for electromagnetic wave shielding

5: electromagnetic wave shielding layer

6: conductive adhesive layer

6P: conductive adhesive layer in drying process

7 b: insulating resin layer

8 c: insulating adhesive layer

9 c: insulating coating

10: adhesive resin precursor

11: conductive filler

12: dendritic particles

15: mold releasing base material

20: substrate

21: electrode for electrochemical cell

22: ground pattern

23: inner through hole

24: solder ball

25: semi-cutting groove

30: electronic component

31: semiconductor chip

32: molding resin

33: bonding wire

40: pressing substrate

51. 52: electronic component mounting board

Claims

1. An electronic component mounting board includes:

a substrate;

an electronic component mounted on at least one surface of the substrate; and

an electromagnetic wave shielding member that covers the substrate from an upper surface of the electronic component, and covers a side surface of a step portion formed by mounting the electronic component and at least a part of the substrate;

the electromagnetic wave shielding member has an electromagnetic wave shielding layer containing a binder resin and a conductive filler,

the surface layer of the electromagnetic wave shielding member is manufactured according to japanese industrial standard B0601: 2001, the kurtosis is 1-8.

2. The electronic component mounting substrate according to claim 1, wherein a surface layer of the electromagnetic wave shielding member is formed in accordance with japanese industrial standard B0601: 2001, the root mean square height Rq is 0.3 to 1.7 μm.

3. The electronic component mounting substrate according to claim 1 or 2, wherein the conductive filler contains at least one of a dendritic conductive filler and a needle-like conductive filler.

4. An electronic component mounting board includes:

a substrate;

an electronic component mounted on at least one surface of the substrate; and

5. The electronic component mounting substrate according to claim 4, wherein a water contact angle of a surface layer of the electromagnetic wave shielding member is 70 ° to 110 °.

6. The electronic component mounting substrate according to claim 4 or 5, wherein the electromagnetic wave shielding member on the electronic component exhibits a cross-cut survival rate of 23/25 or more in a tape adhesion test after a pressure cooker test based on Japanese Industrial Standard K5600 of the electromagnetic wave shielding member.

7. The electronic component mounting substrate according to any one of claims 4 to 6, wherein a surface layer of the electromagnetic wave shielding member is formed in accordance with Japanese Industrial Standard B0601: 2001, the measured kurtosis is 1-8.

8. The electronic component mounting substrate according to any one of claims 4 to 7, wherein a root mean square height of a surface of the electromagnetic wave shielding member is in a range of 0.4 μm to 1.6 μm.

9. The electronic component mounting substrate according to any one of claims 4 to 8, wherein the electromagnetic wave shielding member has a Makrusei hardness of 50N/mm²～312N/mm²。

10. The electronic component mounting substrate according to any one of claims 4 to 9, wherein the adhesive resin is obtained by thermocompression bonding an adhesive resin precursor containing a thermosetting resin and a curable compound having a functional group capable of crosslinking with a reactive functional group of the thermosetting resin.

11. The electronic component mounting substrate according to any one of claims 4 to 10, wherein the electromagnetic wave shielding member has a film thickness of 10 μm to 200 μm.

12. An electronic component mounting board includes:

a substrate;

an electronic component mounted on at least one surface of the substrate; and

the root-mean-square height Rq of the surface layer of the electromagnetic wave shielding member is 0.05 [ mu ] m or more and less than 0.3 [ mu ] m.

13. The electronic component mounting substrate according to claim 12, wherein a root mean square slope Rdq of a surface layer of the electromagnetic wave shielding member is 0.05 to 0.4.

14. The electronic component mounting substrate according to claim 12 or 13, wherein a water contact angle of a surface layer of the electromagnetic wave shielding member is 90 ° to 130 °.

15. The electronic component mounting substrate according to any one of claims 12 to 14, wherein the conductive filler contains at least one of a dendritic and needle-like conductive filler and a scaly conductive filler.

16. An electronic device having the electronic component mounting substrate according to any one of claims 1 to 15 mounted thereon.