JP2002151833A - Manufacturing method of substrate for packaging electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate for packaging electronic components where a sealing resin can be molded relatively easily, and fail or the like due to the outflow of the sealing resin can be reduced. SOLUTION: The manufacturing method of a substrate for packaging electronic compounds comprises an insulating base 11, wiring patterns 12, 13, and 14 formed on one surface of the insulating base 11, and a solder resist layer 16 for covering a surface, excluding the terminal section of the wiring patterns 12, 13, and 14. After the electronic components have been packaged, a junction section with the electronic components is molded the sealing resin. The manufacturing method comprises a process for forming the application layer of a photosolder resist material that becomes the solder resist layer 16, a process for the application layer to light via a photomask 50 having a specific pattern, and process for patterning the application layer by developing the application layer of the photosolder resist material that is exposed to light and for forming at least one step section 20, where the thickness of a region side that is sealed by resin becomes relatively thinner at the boundary between the molded region and the surrounding region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic component mounting board used for mounting electronic components,
CSP (Chip Size Package), BGA (Ball Grid Arr)
ay), μ-BGA (μ-Ball Grid Array), FC (Flip
This is an electronic component mounting board that has almost the same size as electronic components to be mounted, such as a Chip) and a QFP (Quad Flatpack Package). (Hereinafter, simply referred to as “substrate for mounting electronic components”).

[0002]

2. Description of the Related Art With the development of the electronics industry,
The demand for printed wiring boards on which electronic components such as C (integrated circuits) and LSIs (large-scale integrated circuits) are mounted has been rapidly increasing, but there has been a demand for smaller, lighter, and more sophisticated electronic devices. Recently, TAB has been used as a mounting method for these electronic components.
A mounting method using a tape, a T-BGA tape, an ASIC tape, or the like is employed. In particular, as electronic devices become lighter and thinner, electronic components are mounted at a higher density, and in order to improve the reliability of the electronic components, a substrate having a size substantially corresponding to the size of the electronic components to be mounted is required. CSP, BGA, μ-B with external connection terminals arranged almost all over
The use frequency of GA and the like is increasing.

[0003] Such an electronic component mounting board is used by mounting the electronic component and then molding a joint portion with the electronic component with a sealing resin.

FIGS. 13 and 14 show an example of such an electronic component mounting substrate.

[0005] As shown in FIGS.
10 are continuously formed on the tape-shaped insulating film 101. The insulating film 101 has transfer sprocket holes 102 on both sides in the width direction at regular intervals.
In No. 3, two electronic component mounting substrates 110 are provided in the width direction of the insulating film 101.

The electronic component mounting board 110 has an insulating base material 11 having a size substantially corresponding to the size of the electronic component to be mounted.
1, a wiring pattern 112, a device-side connection terminal 113, and an external connection terminal 114 are provided, and between the device-side connection terminal 113, the device-side connection terminal 113 and an electronic component mounted on the back surface side. And a slit 115 for connecting to

[0007] The wiring pattern 112 except for the device-side connection terminals 113 and the external connection terminals 114 is covered with a solder resist layer 116, and a terminal hole 117 is formed in the solder resist layer 116 corresponding to the external connection terminals 114. . The external connection terminals 114 serve as solder ball pads, and are connected to the outside via solder balls.

FIG. 15 shows a state in which electronic components are mounted on such an electronic component mounting board 110. As shown in the figure, an electronic component mounting substrate 110 has an IC as an electronic component.
The device-side connection terminal 113 and the electrode of the IC 130 are connected via a bonding wire 131 by wire bonding.
Slit 115 including device 31 and device-side connection terminal 11
3 is molded with a sealing resin 133.

[0009]

However, since electrodes and wirings are provided close to the periphery of the mold portion, unless the molding with the sealing resin is performed with high precision, the electrodes around the mold portion may not be formed. There is a problem that it is covered with the sealing resin and becomes a defective product.

More specifically, if the terminal hole 117 is provided close to the periphery of the molded portion, the sealing resin 133 flows into the terminal hole 117 as shown in FIG. In the case of 114, a contact failure may occur.

In view of the above circumstances, the present invention provides an electronic component that can relatively easily manufacture an electronic component mounting substrate that can mold a sealing resin relatively easily and reduce defects and the like caused by the flow of the sealing resin. It is an object to provide a method for manufacturing a mounting substrate.

[0012]

According to a first aspect of the present invention, there is provided an insulating base material, a wiring pattern formed on one surface of the insulating base material, and a terminal portion of the wiring pattern. A solder resist layer covering the surface except for, after the electronic component is mounted, in a method of manufacturing an electronic component mounting substrate in which a joint with the electronic component is molded with a sealing resin, the solder resist layer and Forming a coating layer of a photo solder resist material, and exposing the coating layer through a photomask having a predetermined pattern, and developing the coating layer of the exposed photo solder resist material to form the coating layer. At the same time as patterning, at the boundary between the region to be molded and the surrounding region, the step portion where the film thickness on the resin-sealed region side becomes relatively thin is reduced. There is also a method of manufacturing a substrate for an electronic component mounting which is characterized by comprising the step of one form.

In the first aspect, a step portion can be provided in the solder resist layer in a photolithography process using a photo solder resist. The sealing resin is blocked by the step portion, and there is no possibility of the resin leaking to the periphery.

According to a second aspect of the present invention, in the first aspect, a terminal hole for exposing an external connection terminal is formed in the solder resist layer on the side of the step portion opposite to the region to be molded. A method for manufacturing a substrate for mounting electronic components, characterized in that:

According to the second aspect, when the bonding portion of the electronic component or the like is molded after the mounting of the electronic component, the sealing resin is blocked by the step portion, and the terminal holes around the sealing resin are closed by the sealing resin. There is no fear.

According to a third aspect of the present invention, in the manufacturing method of the first or second aspect, the step is formed by a groove provided in the solder resist layer. In the way.

In the third aspect, after mounting the electronic component, when molding the joint portion of the electronic component or the like, the sealing resin is blocked by the groove and the step portion, and does not flow out to the periphery.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the above steps are repeated twice, and a first step is to form a first solder resist layer in a region where the step is formed. And a second coating layer of a photo solder resist material is formed for the second time to form a thick coating portion in the portion where the first solder resist layer is formed, and thereafter, the second coating layer is formed. Forming the step portion in the thick-film-coated portion by exposing and developing the substrate to form the step portion.

In the fourth aspect, a step can be provided in the solder resist layer in two photolithography steps.

According to a fifth aspect of the present invention, in any one of the first to third aspects, a first solder resist layer is formed by screen printing in a region where the step portion is formed, and then a photo solder resist material is formed. By forming a second coating layer, a thick film coating portion is formed in the portion where the first solder resist layer is formed, and thereafter, the second coating layer is exposed, developed, and patterned. The method according to claim 1, wherein the step is formed in the thick film application section.

In the fifth aspect, the first solder resist layer is formed by screen printing, and a step can be formed in the solder resist layer in one photolithography step.

According to a sixth aspect of the present invention, in any one of the first to third aspects, when exposing through the photomask, a complete irradiation area and a half irradiation area are formed. Wherein the step portion is a relatively thin portion of the step portion.

In the sixth aspect, a complete irradiation area and a half irradiation area are formed at the time of exposure through a photomask, and a step is formed in the solder resist layer by one photolithography step. be able to.

According to a seventh aspect of the present invention, in the sixth aspect, it is preferable that a transparent portion corresponding to the completely illuminated region and a semi-transmissive portion corresponding to the semi-illuminated region are formed on the photomask. The present invention is a method for manufacturing a substrate for mounting electronic components.

In the seventh aspect, a semi-transmissive area is provided on a photomask so that a complete irradiation area and a semi-irradiation area are formed at the time of exposure, and a step is formed on the solder resist layer in one photolithography step. Part can be formed.

According to an eighth aspect of the present invention, in the sixth aspect, the photomask is divided into two parts in the feed direction of the irradiation object to form basically the same pattern in the first region and the second region. In addition, by exposing the object to be irradiated by halving the feed amount, exposure through the first region of the photomask and exposure through the second region are performed continuously, and the first exposure of the photomask is performed. A region in which a transmission portion is provided in both the first and second regions is the complete irradiation region, and a region in which a transmission portion is provided in only one of the first and second regions is the half irradiation region. A method for manufacturing a substrate for mounting electronic components.

In the eighth aspect, the photomask is divided into two parts, and the irradiation amount of the irradiation target is reduced to half, and the exposure is performed twice in one photolithography step, so that the complete irradiation region and the half irradiation To form an area,
A step can be formed in the solder resist layer in one photolithography process.

According to a ninth aspect of the present invention, there is provided an insulating base material, a wiring pattern formed on one surface of the insulating base material, and a solder resist layer for covering the surface of the wiring pattern excluding the terminals. Forming a solder resist layer on a predetermined region in the method of manufacturing an electronic component mounting board in which a joint with the electronic component is molded with a sealing resin after the electronic component is mounted; Forming at least one groove having a relatively thin film thickness at a boundary portion between the molded region and a peripheral region of the resist layer by physical processing. A method for manufacturing a component mounting board.

In the ninth aspect, after the solder resist layer is formed, a step is formed by physical processing, so that when the electronic component is mounted and the joining portion of the electronic component or the like is molded, the sealing resin is removed. It was made to be dammed in the department.

[0030] A tenth aspect of the present invention is the method for manufacturing an electronic component mounting board according to the ninth aspect, wherein the physical processing is laser processing.

In the tenth aspect, after the solder resist layer is formed, a step is provided by laser processing, so that when the electronic component is mounted and the joining portion of the electronic component or the like is molded, the sealing resin is removed from the step. To be dammed.

According to an eleventh aspect of the present invention, in the ninth or tenth aspect, the solder resist layer is formed by forming a coating layer of a photo solder resist material, and forming a predetermined transmission portion pattern on the coating layer. Electronic component mounting, which is performed by a step of exposing through a photomask having: and a step of developing a coating layer of the exposed solder resist material and patterning the coating layer to form a solder resist layer. In a method of manufacturing a substrate for use.

In the eleventh aspect, after forming a solder resist layer using a photo solder resist material, a step portion is provided by physical processing, so that after the electronic component is mounted, a joint portion of the electronic component or the like is molded. At this time, the sealing resin was blocked at the step.

According to a twelfth aspect of the present invention, in the ninth or tenth aspect, the solder resist layer is formed by forming a coating layer of a solder resist material in a predetermined area by screen printing, And a step of curing the solder resist layer to form a solder resist layer.

In the twelfth aspect, a step is formed by physical processing after forming a solder resist layer using a thermosetting type solder resist material. When molding
The sealing resin is blocked at the step.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic component mounting board according to an embodiment of the present invention will be described together with its manufacturing method and usage examples. Of course, it goes without saying that the present invention is not limited to this.

FIG. 1 is a schematic plan view of an electronic component mounting substrate manufactured by the method of the present invention, and FIG.

As shown in FIGS. 1 and 2, a plurality of electronic component mounting substrates 10 are continuously formed on a tape-shaped insulating film 1. The insulating film 1 has transfer sprocket holes 2 on both sides in the width direction at regular intervals. Generally, electronic components are mounted while being transferred, and after the electronic components are mounted, the electronic component mounting substrate 10 is cut. Is done. In FIG. 1, two electronic component mounting substrates 10 are provided in the width direction of the insulating film 1.

The electronic component mounting board 10 has a wiring pattern 12 and device-side connection terminals 13 on almost the entire surface of an insulating base material 11 having a size substantially corresponding to the size of the electronic component to be mounted.
And an external connection terminal 14. A slit 1 for connecting the device-side connection terminal 13 to an electronic component mounted on the back surface side is provided between the device-side connection terminals 13.
5 is provided.

The wiring pattern 12 excluding the device-side connection terminals 13 and the external connection terminals 14 has a solder resist layer 1
6, a terminal hole 17 is formed in the solder resist layer 16 corresponding to the external connection terminal 14. That is, the external connection terminal 14 becomes a solder ball pad and is connected to the outside via the solder ball.

Further, the terminal holes 17 arranged inside are provided.
And the device side connection terminal 13, the terminal hole 1
A step portion 20 in which the device-side connection terminal 13 is lower than the device side connection terminal 13 is formed. Here, the device side connection terminal 13 side of the stepped portion 20 is a groove 21, and the stepped portion 20 and the groove 21 are formed with the terminal hole 17 and the device side connection terminal 13.
Are provided in the longitudinal direction of the slit 15.

Incidentally, an adhesive layer 19 for temporarily fixing electronic components is generally provided on the back surface side of the insulating base material 11. However, the adhesive layer 19 is not always necessary for the electronic component mounting substrate.

Here, the insulating film 1 (insulating base material 11)
For example, a material having flexibility, chemical resistance, and heat resistance can be used. Examples of the material of the insulating film 1 include polyester, polyamide, and polyimide. Particularly, a wholly aromatic polyimide having a biphenyl skeleton (for example, trade name: Upilex; Ube Industries, Ltd.) is preferable. In addition, the thickness of the insulating film 1 is generally 25 to 125 μm, preferably 25 to 75 μm.

The wiring patterns 12, device-side connection terminals 13, and external connection terminals 14 provided on the surface of the insulating film 1 are generally formed by patterning a conductive foil made of copper or aluminum. Such a conductive foil may be directly laminated on the insulating film 1 or may be formed by thermocompression bonding or the like via an adhesive layer. The thickness of the conductor foil is, for example, 6 to 70 μm, preferably 8 to 70 μm.
35 μm. As the conductor foil, a copper foil, particularly an electrolytic copper foil is preferable in consideration of etching characteristics, operability, and the like.

Instead of providing a conductor foil on the insulating film 1, for example, a polyimide precursor may be applied to the conductor foil and baked to form the insulating film 1 made of a polyimide film.

The conductor foil provided on the insulating film 1 is patterned as a wiring pattern 12, device-side connection terminals 13 and external connection terminals 14 by photolithography. That is, after the photoresist layer is applied, the photoresist layer is patterned by exposure and development through a photomask, and the patterned photoresist layer is used as a mask to be chemically dissolved (etched) with an etchant and removed. Then, the conductor foil is patterned by dissolving and removing the photoresist with an alkali solution or the like.

Next, a solder resist material coating solution is applied on the conductor foil thus patterned,
By a predetermined patterning, a solder resist layer 16 is formed.

Further, the wiring pattern 12 not covered by the solder resist layer 16 and the device-side connection terminal 1
3 and the external connection terminals 14 are generally plated. Examples of such plating include tin plating, solder plating, gold plating, nickel-gold plating, and the like, and are selected according to the mounting method of the electronic component.
For example, nickel-gold plating is preferable for mounting by wire bonding. Here, as a material for forming the solder resist layer 16, when the step portion 20 or the like is formed by photolithography,
A photo solder resist material is used.

The photo solder resist material may be a negative type or a positive type, as long as it has the properties of a general photoresist and the property of protecting a conductive foil. For example, particularly, a photopolymerization initiator or the like is added to a photosensitive resin such as an epoxy acrylate resin. Examples of the epoxy acrylate resin include a bisphenol A type epoxy acrylate resin, a novolak type epoxy acrylate resin, a bisphenol A type epoxy methacrylate resin, and a novolak type epoxy methacrylate resin.

The photo solder resist material is dissolved or dispersed in an organic solvent and applied as a coating solution.
A curing accelerator, a filler, an additive, a thixotropic agent and the like can be added to the coating liquid. Further, in order to improve the properties such as flexibility of the solder resist layer 16, fine particles having elasticity such as rubber fine particles can be blended.

As an example of the composition of the photo solder resist material coating solution, 35 to 45% of an acrylate resin, 0.1 to 5% of an acrylate monomer, 0.1 to 5% of an epoxy curing agent, and 0.1 of a coloring pigment ~ 5%, extender pigment 10
-20%, additive 0.1-5%, photopolymerization initiator 1-10
%, And a mixture of 30 to 40% of an organic solvent. Such a photo solder resist material coating solution is applied, for example, to a film thickness of about 20 to 50 μm, and dried and exposed to hot air at about 80 ° C. for about 30 minutes, for example, and then exposed and developed. After development, if necessary, for example,
It is heat-treated at about 150 ° C. for about 60 minutes and is thermally cured.

The thickness of the solder resist layer 16 formed in this manner is, for example, 20 to 50 μm.
It is preferable that the relatively thin portion of 0 has a thickness of 1 to 20 μm. If the thickness is smaller than this range, a problem may occur in terms of the effect of protecting the lower wiring pattern and the like, and if the thickness is larger than this range, the damping action of the sealing resin as the step portion may not be remarkable. is there.

When the steps 20 and the like are formed by laser processing instead of photolithography, a general solder resist material coating solution that is applied only to a necessary area by a screen printing technique and thermally cured is used. Can be used.

Such a solder resist material coating solution is obtained by dissolving or dispersing a curable resin in an organic solvent. Examples of the curable resin include an epoxy resin, an elastomer-modified epoxy resin, a urethane resin, and a urethane resin. Examples include modified elastomers, polyimide resins, modified elastomers of polyimide resins, and acrylic resins. In the coating liquid, curing accelerators, fillers, additives,
A thixotropic agent or the like can be added. Further, in order to improve the properties such as flexibility of the solder resist layer 16, fine particles having elasticity such as rubber fine particles can be blended. In addition, such a solder resist material coating liquid is applied only to a necessary region by screen printing, and is thermally cured to form the solder resist layer 16. In addition, as a solder resist material coating solution used for screen printing, a photo solder resist material coating solution may be used.

Electronic components to be mounted are temporarily fixed on the surface (back surface) on the opposite side of the insulating film 1 on which the wiring pattern 12, the device-side connection terminals 13, the external connection terminals 14, and the solder resist layer 16 are provided. After the formation of the adhesive layer 19, the slits 15 are formed to obtain an electronic component mounting substrate film carrier tape.

Here, the adhesive layer 19 is preferably formed using a thermosetting and elastic adhesive, and may be formed by directly applying to the back surface,
It may be formed using an adhesive tape. In addition, the adhesive layer 19 does not need to be provided in the entire region where the electronic component is mounted, but may be provided in a partial region.

As shown in FIG. 3, the electronic component mounting board 10 has an IC 30 mounted thereon as an electronic component.
Device side connection terminals 13 and I
The electrode of C30 is connected via a bonding wire 31, and the slit 15 including the bonding wire 31 and the device-side connection terminal 13 are molded with a sealing resin 33.

Here, the sealing resin 33 does not flow into the terminal hole 17 due to the action of the groove 21 and the stepped portion 20, so that a poor connection at the external connection terminal 14 can be prevented.

The electronic component mounting substrate 10 is cut off after the electronic components are mounted on the film carrier tape as it is, and after the electronic components are cut one by one, the electronic components are mounted. There are cases.

FIGS. 4 to 7 show other examples of the electronic component mounting substrate manufactured by the method of the present invention and cross sections showing the manner of use thereof.

As shown in FIG. 4A, the electronic component mounting substrate 10A has a thin film portion 22A having a relatively thin film thickness inside the stepped portion 20A, that is, the slit 15 side is close to the device side connection terminal 13. The configuration is basically the same as that of the above-described embodiment except for the following.

With such a structure, as shown in FIG. 4B, the IC 30 as an electronic component is mounted, and the device-side connection terminal 13 and the IC 30 are connected by wire bonding.
When the slit 15 including the bonding wire 31 and the device-side connection terminal 13 are molded with the sealing resin 33, the sealing resin 33 is dammed by the step portion 20A,
Inflow to the terminal hole 17 is prevented.

As shown in FIG. 5, the electronic component mounting substrate 1
FIG. 2B shows a point having a step 20B and a groove 21B in FIG.
However, the edge portions on both sides in the width direction of the groove 21B are thick film portions 23B. That is, the groove 21B is formed in the thick film portion 23B thicker than the standard film thickness in the other region.

The thick film portion 23B is provided in a bank shape, and is provided near the device-side connection terminal 13 and the terminal hole 1B.
The solder resist layer 16 in the vicinity of 7 has a standard thickness so as not to adversely affect wire bonding and bonding with solder balls in a later step.

With such a structure, as shown in FIG. 5B, the IC 30 as an electronic component is mounted, and the device-side connection terminal 13 and the IC 30 are connected by wire bonding.
When the slit 15 including the bonding wire 31 and the device-side connection terminal 13 are molded with the sealing resin 33, the sealing resin 33 is dammed by the step portion 20B and the groove 21B. , To the terminal hole 17 is prevented.

As shown in FIG. 6, the electronic component mounting substrate 1
5C in that it has a step 20C and a groove 21C.
The structure is the same as that of FIG. 5 except that the thick film portions 23C at the edges on both sides in the width direction of the groove 21C are not bank-shaped and are provided in a slightly wider area.

With such a structure, as shown in FIG. 6B, the IC 30 as an electronic component is mounted, and the device-side connection terminal 13 and the IC 30 are connected by wire bonding.
When the slit 15 including the bonding wire 31 and the device-side connection terminal 13 are molded with the sealing resin 33, the sealing resin 33 is dammed by the step portion 20C and the groove 21C. , To the terminal hole 17 is prevented.

It should be noted that even if the thick film portion 23C is formed up to the vicinity of the device side connection terminal 13 and the vicinity of the terminal hole 17, it is assumed that it does not adversely affect the wire bonding and the bonding with the solder ball in a later process. Become.

As shown in FIG. 7, the electronic component mounting substrate 1
0D is a thick film portion 23 in which the step portion 20D is formed in a bank shape.
D. As described above, the step portion does not necessarily need to be formed by the groove or the thin film portion, but can be formed by providing the thick film portion 23D thicker than the standard film thickness.

With such a structure, as shown in FIG. 7B, the IC 30 as an electronic component is mounted, and the device-side connection terminal 13 and the IC 30 are connected by wire bonding.
When the slit 15 including the bonding wire 31 and the device-side connection terminal 13 are molded with the sealing resin 33, the sealing resin 33 is dammed by the step portion 20D,
The flow to the terminal hole 17 is prevented.

The thick film portion 23D may be provided up to the edge of the terminal hole 17 as long as it does not adversely affect the bonding with the solder ball.

Although the modified example of the structure of the electronic component mounting board manufactured by the method of the present invention has been described above, it is needless to say that the present invention is not limited to this.

An embodiment of a manufacturing method for manufacturing the electronic component mounting board as described above will be described below.

FIG. 8 shows a manufacturing method according to the first embodiment. This manufacturing method is basically suitable for manufacturing an electronic component mounting substrate having the structure shown in FIGS.
The present invention is also applicable to a method for manufacturing an electronic component mounting board having the structure shown in FIG.

In this manufacturing method, first, as shown in (a), a conductive foil provided on an insulating film 1 serving as an insulating base material 11 is patterned by photolithography to form a wiring pattern 12, a device-side connection terminal. 13, the external connection terminals 14 are formed (here, the wiring patterns 12
As illustrated). Since this step is a generally known method, the details are omitted.

Next, as shown in (b), the photo solder resist material coating layer 4 is coated so as to cover the wiring pattern 12.
1 is applied.

Next, as shown in (c), exposure is performed through a photomask 50, and further development is performed to form a patterned solder resist layer 16 as shown in (d).

Here, a negative type is used as the photo solder resist material, and the photo mask 50 includes a light blocking portion 51 for blocking light, a transmitting portion 52 for transmitting light, and a semi-transmitting portion for transmitting substantially half of the light. 53 was used. The entire thickness of the photo solder resist material coating layer 41 is hardened by exposure in the region facing the transmission portion 52 to become the solder resist layer 16, while the region facing the light blocking portion 51 is not exposed at all and is removed by development. As a result, a terminal hole 17 is formed. Also, the semi-transmissive part 53
In the region opposed to, only a part of the thickness of the photo solder resist material coating layer 41 is hardened by exposure and a part of the thickness is removed by development, so that the groove 21 is formed.

Thereafter, as shown in (e), an adhesive layer 19 is formed on the back surface of the insulating film 1, and further (f)
As shown in (1), the slit 15 is formed, and the electronic component mounting substrate 10 is completed.

In the manufacturing method described above, a special photomask 50 having a light blocking portion 51 for blocking light, a transmitting portion 52 for transmitting light, and a semi-transmitting portion 53 for transmitting substantially half of the light is used. Thus, the photo solder resist material coating layer 41 can be formed by one photolithography process.
Can be formed at the same time as the terminal hole 17 from which is completely removed and the groove 21 with a part of the thickness left.

FIG. 9 shows a manufacturing method according to the second embodiment. This manufacturing method is basically suitable for manufacturing an electronic component mounting substrate having the structure shown in FIGS.

Also in this manufacturing method, first, as shown in (a), the conductive foil provided on the insulating film 1 serving as the insulating base material 11 is patterned by photolithography to form the wiring pattern 12, the device-side connection terminals. 13, the external connection terminals 14 are formed (here, the wiring patterns 12
As illustrated). Since this step is a generally known method, the details are omitted.

Next, as shown in (b), a first photo solder resist material coating layer 43 is applied so as to cover the wiring pattern 12 and is exposed through a photo mask 60.
Further, development is performed to form a solder resist layer 16A patterned as shown in FIG.

Here, a negative type was used as a photo solder resist material, and a photo mask 60 having a light blocking portion 61 for blocking light and a transmitting portion 62 for transmitting light was used. In a region opposed to the transmission portion 62, the photo solder resist material coating layer 43 is cured by exposure to become a solder resist layer 16A, while in a region opposed to the light blocking portion 61, it is not exposed at all and is removed by development.

Next, as shown in (d), a second photo solder resist material coating layer 45 is applied. At this time, a portion corresponding to the solder resist layer 16A becomes a thick film. Subsequently, this is exposed through a photomask 60A and developed. Here, the photomask 60A includes a light blocking unit 61A and a transmitting unit 62A.

As a result, patterning is performed as shown in (e), the terminal hole 17 and the groove 21B are formed, and the portion where the groove 21B is formed becomes the thick film portion 23B.

Thereafter, as shown in (f), an adhesive layer 19 is formed on the back surface of the insulating film 1, and (g)
As shown in (1), the slit 15 is formed, and the electronic component mounting substrate 10B is completed.

In the manufacturing method described above, the light blocking portions 61 and 61A for blocking light and the transmitting portions 62 and 6 for transmitting light are provided.
Although the general photomasks 60 and 60A having a thickness of 2A are used, the photolithography process is repeated twice to form a groove in the thick film portion formed in advance, so that the thick film together with the terminal hole 17 is formed. Groove 21 in part 23B
B can be formed.

FIG. 10 shows a manufacturing method according to the third embodiment. This manufacturing method is basically suitable for manufacturing an electronic component mounting substrate having the structure shown in FIGS.

This manufacturing method is the same as that of the second embodiment except that the solder resist layer 16A shown in FIG. 9C is formed by a screen printing method. .

In this embodiment, after the wiring pattern 12 is formed on the insulating substrate 11, the solder resist layer 16B is formed by a screen printing method. That is, using a screen mask of, for example, 180 mesh, which has a predetermined pattern formed by masking the area other than the solder resist coating portion with the emulsion, and superimposing the screen mask on the wiring pattern 12, applies a solder resist material coating liquid. Thereafter, the solder resist layer 1 is cured by heat.
6B is formed.

The solder resist material coating solution used here is a general one having no photosensitivity as described above.
That is, a curable resin is dissolved or dispersed in an organic solvent.As the curable resin, epoxy resin, elastomer modified epoxy resin, urethane resin, elastomer modified urethane resin, polyimide resin, polyimide Examples of the modified resin include an elastomer modified product and an acrylic resin. A curing accelerator, a filler, an additive, a thixotropic agent, and the like can be added to the coating liquid. Further, in order to improve the properties such as flexibility of the solder resist layer, fine particles having elasticity such as rubber fine particles can be blended. In addition, you may use a photo solder resist material coating liquid as a solder resist material coating liquid used for screen printing.

In the manufacturing method described above, since the solder resist layer 16B can be formed by a screen printing method having a smaller number of steps than in the photolithography step, the groove 21B can be easily formed in a simpler step than in the second embodiment. can do.

FIG. 11 further shows a manufacturing method according to the fourth embodiment. This manufacturing method uses a special photomask 70 as shown in FIG. 12 and reduces the feed amount of the insulating film 1 in the photolithography process to half, thereby removing the portion where the photo solder resist material coating layer 41 is completely removed. , And a part that leaves a part of the thickness can be formed simultaneously in one step. Basically,
It is suitable for manufacturing the electronic component mounting board shown in FIGS.

The insulating film 1 is actually in the form of a tape, and the photolithography process described later is continuously performed. However, in the illustration and description, the process is performed only on one electronic component mounting substrate. . Further, in practice, exposure of a plurality of electronic component mounting substrates is performed with one photomask, but for simplicity, only the transmission portion pattern corresponding to one electronic component mounting substrate is illustrated.

As shown in FIG. 12, the photomask 70 used in this manufacturing method is an insulating film 1 which is an object to be irradiated.
And a first area 70A and a second area 70B. In both regions, basically the same pattern consisting of the light blocking portion 71 and the transmitting portion 72 is basically formed, and the same irradiation target is halved and the same irradiation target is divided into the first region 70A and the first irradiation region. Exposure is performed twice using the second region 70B. Therefore, when a negative-type photo solder resist is used, only the portion that has been exposed twice is completely cured and remains as the solder resist layer 16. In addition, in this example, the second region 7
A light blocking portion 73 formed only in the area 0B is provided, and only this area is exposed only once out of the two exposures.
The light blocking portion 73 is formed in a region facing the groove 21 in this example.

In the manufacturing method using such a photomask 70, first, as shown in FIG. 11A, exposure is performed through the first region 70A, and as shown in FIG.
After the half-feed, the exposure through the second area 70B is performed. Thereafter, the pattern (c) is formed by developing.

In this case, since the negative type photo solder resist material is used, the region of the photo solder resist material coating layer 41 facing the light blocking portion 71 is not cured at all, and becomes the terminal hole 17 and the like, and the light transmitting portion is formed. A relatively thick solder resist layer 16 is formed in a region co-exposed twice in the region facing 72. On the other hand, in the first exposure, the region is exposed to the transmission portion 72, but in the second exposure, the region which is not exposed to the light blocking portion 73 is exposed once and only approximately half of the thickness is cured. Then, the solder resist layer 16 having a relatively small thickness remains and becomes a groove 21.

In the manufacturing method described above, the exposure is performed twice by using the photomask 70 divided into two parts and by half-feeding the irradiation object, so that the terminal where the photo solder resist material coating layer 41 is completely removed is removed. The hole 17 and the groove 21 with a part of the thickness left can be formed in one process. Although the feed amount is reduced to half in this manufacturing method, it is significantly more efficient than a method in which the photolithography step is repeated twice.

In the manufacturing method described above, the step portion 20 or the groove 21 is basically formed by photolithography, but the step portion 20 or the groove 21 is formed on the solder resist layer 16 by physical processing such as laser processing. The groove 21 may be processed.

The material of the solder resist layer 16 at this time is not limited to the photo solder resist layer, but may be a solder resist layer 16 which is applied to a predetermined region by a screen printing method or the like and is cured by heat. You may.

[0102]

As described above, according to the manufacturing method of the present invention, the film thickness on the resin-sealed region side is formed at the boundary between the molded region of the solder resist layer and the surrounding region. An electronic component mounting substrate having a relatively thin step can be manufactured relatively easily, and by using this,
When the sealing resin is molded after mounting the electronic components, there is no possibility that the sealing resin flows out to the surroundings due to the action of the step portion, and particularly, it does not flow into the terminal hole formed close to the external connection. This has the effect of preventing poor connection at the terminals and the like.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an example of an electronic component mounting substrate manufactured by a method of the present invention.

FIG. 2 is a sectional view of an example of an electronic component mounting substrate manufactured by the method of the present invention.

FIG. 3 is a cross-sectional view showing an example of use of an example of an electronic component mounting substrate manufactured by the method of the present invention.

FIG. 4 is a cross-sectional view showing a schematic configuration and usage of another example of an electronic component mounting board manufactured by the method of the present invention.

FIG. 5 is a cross-sectional view showing a schematic configuration and usage of another example of an electronic component mounting board manufactured by the method of the present invention.

FIG. 6 is a cross-sectional view showing a schematic configuration and usage of another example of an electronic component mounting substrate manufactured by the method of the present invention.

FIG. 7 is a cross-sectional view showing a schematic configuration and usage of another example of an electronic component mounting board manufactured by the method of the present invention.

FIG. 8 is a sectional view illustrating the method for manufacturing the electronic component mounting board according to the first embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating the method for manufacturing the electronic component mounting board according to the second embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a method for manufacturing an electronic component mounting board according to Embodiment 3 of the present invention.

FIG. 11 is a cross-sectional view illustrating a method for manufacturing an electronic component mounting board according to Embodiment 4 of the present invention.

FIG. 12 is a plan view illustrating an example of a photomask used in the method for manufacturing an electronic component mounting board according to Embodiment 4 of the present invention.

FIG. 13 is a plan view illustrating a schematic configuration of an example of an electronic component mounting board according to the related art.

FIG. 14 is a cross-sectional view of an example of an electronic component mounting board according to the related art.

FIG. 15 is a cross-sectional view illustrating a usage example of an example of an electronic component mounting board according to the related art.

[Explanation of symbols]

10, 10A, 10B, 10C, 10D Electronic component mounting substrate 11 Insulating base material 12 Wiring pattern 13 Device side connection terminal 14 External connection terminal 15 Slit 16, 16A, 16B Solder resist layer 17 Terminal hole 19 Adhesive layer 20, 20A , 20B, 20C, 20D Step portion 21, 21B, 21C Groove 22A Thin film portion 23B, 23C, 23D Thick film portion 30 IC (electronic component) 31 Bonding wire 33 Sealing resin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E314 AA27 BB06 BB09 BB11 CC06 DD07 FF06 FF19 GG01 5F061 AA01 BA04 BA05 CA06 CA12 CB12

Claims (12)

[Claims] 1. An electronic component comprising: an insulating base material; a wiring pattern formed on one surface of the insulating base material; and a solder resist layer covering a surface of the wiring pattern excluding a terminal portion. Then, in a method for manufacturing an electronic component mounting substrate in which a joint with an electronic component is molded with a sealing resin, a step of forming a coating layer of a photo solder resist material to be the solder resist layer, Exposing through a photomask having a predetermined pattern,
The exposed coating layer of the photo solder resist material is developed to pattern the coating layer, and the thickness of the resin-encapsulated region is relatively close to the boundary between the molded region and the surrounding region. Forming at least one stepped portion that has been made thinner. 2. The electronic component mounting according to claim 1, wherein a terminal hole for exposing an external connection terminal is formed in the solder resist layer on the opposite side of the stepped portion from the region to be molded. Method of manufacturing substrates. 3. The method according to claim 1, wherein the step is formed by a groove provided in the solder resist layer. 4. The method according to claim 1, wherein each of the steps is repeated twice, and in the first time, a first solder resist layer is formed in a region where the step portion is to be formed, and a second photo soldering is performed. By forming a second coating layer of a resist material, a thick film coating portion is formed in a portion where the first solder resist layer is formed, and thereafter, the second coating layer is exposed and developed for patterning. By doing
A method for manufacturing a substrate for mounting electronic components, wherein the step portion is formed in the thick film application portion. 5. The method according to claim 1, wherein a first solder resist layer is formed by screen printing in a region where the step portion is formed, and then a second coating layer of a photo solder resist material is formed. By doing so, the first
Forming a thick film application portion on the portion where the solder resist layer is formed, and then exposing and developing the second coating layer to pattern the thick film application portion, thereby forming the step portion in the thick film application portion. A method of manufacturing a substrate for mounting electronic components, which is a feature of the present invention. 6. The method according to claim 1, wherein a full irradiation area and a half irradiation area are formed at the time of exposure through the photomask, and the half irradiation area is relatively positioned with respect to the step portion. A method for manufacturing a substrate for mounting electronic components, characterized in that the film thickness is a thin portion. 7. The electronic component mounting board according to claim 6, wherein a transparent portion corresponding to the completely illuminated region and a semi-transmissive portion corresponding to the semi-illuminated region are formed on the photomask. Manufacturing method. 8. The method according to claim 6, wherein the photomask is divided into two parts in the feed direction of the irradiation object to form basically the same pattern in the first region and the second region, and the feed amount of the irradiation object. By half, the exposure through the first area of the photomask and the exposure through the second area are performed successively, and the exposure is performed on both the first and second areas of the photomask. A region provided with a transmission portion is the complete irradiation region, and a region provided with a transmission portion in only one of the first and second regions is the semi-irradiation region. Substrate manufacturing method. 9. An electronic component, comprising: an insulating base material; a wiring pattern formed on one surface of the insulating base material; and a solder resist layer covering a surface of the wiring pattern excluding terminals. Forming a solder resist layer in a predetermined area, wherein the solder resist layer is molded in a predetermined region. Forming at least one groove having a relatively thin film thickness at a boundary portion between the region and a peripheral region by physical processing. . 10. The method according to claim 9, wherein the physical processing is laser processing. 11. The solder resist layer according to claim 9, wherein the solder resist layer is formed by forming a coating layer of a photo solder resist material and exposing the coating layer via a photomask having a predetermined transmission portion pattern. And a step of developing the exposed coating layer of the solder resist material and patterning the coating layer to form a solder resist layer. 12. The solder resist layer according to claim 9, wherein the solder resist layer is formed by forming a coating layer of a solder resist material in a predetermined area by screen printing, and curing the coating layer. A method for manufacturing a substrate for mounting electronic components, characterized by the following steps: