JP2008130577A - Process for producing electronic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate production of an electronic substrate having a stabilized structure in which cracking does not occur easily. <P>SOLUTION: The electronic substrate has electronic components 20 and 21, and conduction wiring connected by the wiring joints 20a and 21a of the electronic components 20 and 21. The process for producing an electronic substrate comprises a step for mounting the electronic components 20 and 21 while abutting the wiring joints 20a and 21a against the surface of a base S, a step for forming an insulating layer 60A around the electronic components 20 and 21 on the surface of the base S by applying a photocuring and thermosetting insulating material with a thickness thinner than that of the electronic components 20 and 21, a step for forming a resin layer 13 in which the electronic components 20 and 21 are embedded on the insulating layer 60A, and a step for forming conduction wiring on the insulating layer 60A by stripping the base S from the electronic components 20 and 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic substrate manufacturing method.

  In recent years, electronic components mounted on a circuit board (wiring board) have been miniaturized, and the wiring board has been required to be finer. As a method for forming such a fine wiring structure, there is a technique in which a conductive pattern is embedded in an insulating film by using a droplet discharge method (see, for example, Patent Document 1).

Also, in recent years, downsizing of electronic devices on which the circuit board is mounted, such as mobile phones, has been progressing. In connection with this, the mounting space of the electronic component on a circuit board (wiring board) is restricted in the mobile phone. Therefore, it is desired to provide a method for mounting electronic components at a higher density.
Therefore, the chip component is fixed on the substrate, an insulating material is applied around the chip component by using a droplet discharge method, the chip component is embedded in the insulating film, and a wiring connected to the chip component is formed. Thus, a wiring board on which chip components are mounted with high density can be considered.

  However, in such a method, stress may remain at the interface between the insulating patterns formed separately as the insulating material is cured and contracted. For this reason, when an external impact or heat is applied, the interface may crack.

Therefore, in Patent Document 2, an insulating material having photocurability and thermosetting is used, and a conductive material droplet is applied to a lower insulating layer which is irradiated with light to be in a semi-cured state. After forming the material layer, an insulating material is applied so as to cover the lower insulating layer and the conductive material layer, and these are heated together, thereby simultaneously curing the lower insulating layer and the upper insulating layer. A method is disclosed that leaves no stress in between.
JP 2005-327985 A JP 2006-121039 A

However, the following problems exist in the conventional technology as described above.
When an insulating material having the above photo-curing properties and thermosetting properties is applied and heated around an electronic component such as a chip component, only the insulating material is cured and cracks occur. It is conceivable to use a resin that does not easily cause cracks.
However, since the wiring connected to the electronic component is formed on the resin material in which the electronic component is embedded, it is covered with the insulating material having the photo-curing property and the thermosetting property. Or, when heat or the like is applied, cracks may occur at the interface.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing an electronic substrate that can easily manufacture a structurally stable electronic substrate that is difficult to crack.

In order to achieve the above object, the present invention employs the following configuration.
The method for manufacturing an electronic board according to the present invention is a method for manufacturing an electronic board having an electronic component and a conductive wiring connected to the wiring connection portion of the electronic component, wherein the wiring connection portion is applied to the surface of a substrate. A step of placing the electronic component in contact with each other, and applying an insulating material having a photocurable property and a thermosetting property to a thickness smaller than the thickness of the electronic component, around the electronic component on the surface of the base material Forming an insulating layer, forming a resin layer embedding the electronic component on the insulating layer, peeling the base material from the electronic component, and forming the conductive wiring on the insulating layer. And a step of forming.
Therefore, in the electronic substrate manufacturing method of the present invention, since most of the electronic components can be surrounded by the resin layer, the use of the soft resin layer makes it difficult for cracks to occur even when the resin layer is cured and contracted. Further, by sufficiently reducing the thickness of the insulating layer, it is possible to prevent the insulating layer from being cracked.
And in this invention, since the one side of the said wiring connection part and the said conductive wiring has photocurability and thermosetting rather than a resin layer, for example, since the other surface side also contacts the insulating layer excellent in migration resistance By forming with the same material, it is possible to obtain a state in which no stress remains between the insulating layers, and it is possible to obtain a structurally stable electronic substrate in which cracks are not easily generated.
Further, in the present invention, an electronic substrate in which the electronic component is embedded in a simple process in which an insulating material and a resin layer are sequentially formed around the electronic component placed on the surface of the base material and then the base material is peeled off. In addition, it is possible to easily form the wiring connection portion and the insulating layer of the electronic component flush with each other.

In the present invention, the insulating layer is formed in a semi-cured state, and the insulating material is applied on the insulating layer so as to cover the conductive wiring, and the second insulating layer in a semi-cured state is formed. A procedure including a film forming step and a step of heating and curing the semi-cured insulating layer and the second insulating layer in a lump can also be suitably employed.
Therefore, in the method for manufacturing an electronic substrate according to the present invention, the conductive wiring can be easily formed on the semi-cured insulating layer, and both layers are simultaneously cured when the insulating layer and the second insulating layer are heated. Thus, no stress is left between the insulating layers.

Further, in the above case, according to the present invention, a step of forming a second conductive wiring provided on the second insulating layer and electrically connected to the conductive wiring; and the second conductive wiring formed of the insulating material. A procedure including a step of forming a third insulating layer covering the substrate can also be suitably employed.
Therefore, according to the present invention, a high-quality multilayer wiring board can be obtained in which conductive wiring is formed across a plurality of layers with an insulating layer interposed therebetween and no cracks are generated.

As the surface of the substrate, a configuration having adhesiveness can be suitably employed.
Therefore, in the present invention, the electronic component placed on the surface of the substrate can be easily positioned at a predetermined position without moving.

Moreover, in this invention, it has the process of affixing the said base material on the one surface of the flame | frame which has the through-hole of the said predetermined shape, covering the said through-hole, on the surface of the said base material exposed in the said through-hole A procedure for placing the electronic component can also be suitably employed.
Therefore, in the method for manufacturing an electronic substrate of the present invention, the outer shape of the insulating layer and the resin layer applied around the electronic component can be set to the predetermined shape of the through hole, and an electronic substrate having a desired shape can be easily manufactured. Is possible.

Moreover, in said case, as the said through-hole, the structure formed in the taper shape diameter-reduced toward the other surface side from the said one surface side can be employ | adopted suitably.
Thereby, in this invention, after peeling a base material, by extruding an electronic substrate toward the one surface side from the said other surface side of a through-hole, the manufactured electronic substrate can be easily extracted (taken out) from a flame | frame. It becomes possible. Further, in the present invention, since the other surface side is pushed out rather than the one surface side where the wiring connection portion and the conductive wiring are provided, the wiring connection portion and the conductive wiring can be prevented from being damaged, and the high-quality electronic substrate Can be obtained.

Hereinafter, an embodiment of an electronic substrate manufacturing method according to the present invention will be described with reference to FIGS.
In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

(Droplet discharge device)
First, a droplet discharge device used in a method for manufacturing a multilayer wiring board according to the present invention will be described with reference to FIGS.
A droplet discharge device 1 shown in FIG. 1 is basically an ink jet device. More specifically, the droplet discharge device 1 includes a tank 101 that holds the liquid material 111, a tube 110, a ground stage GS, a discharge head unit (droplet discharge head) 103, a stage 106, a first The position control device 104, the second position control device 108, the control unit 112, the light irradiation device 140, and the support unit 104a are provided.

The discharge head unit 103 holds a head 114 (see FIG. 2). The head 114 ejects droplets of the liquid material 111 in response to a signal from the control unit 112. Note that the head 114 in the discharge head unit 103 is connected to the tank 101 by the tube 110, and thus the liquid material 111 is supplied from the tank 101 to the head 114.
The stage 106 provides a plane for fixing a substrate (described later). Further, the stage 106 also has a function of fixing the position of the substrate using a suction force.

  The first position control device 104 is fixed at a predetermined height from the ground stage GS by the support portion 104a. The first position control device 104 has a function of moving the ejection head unit 103 along the X-axis direction and the Z-axis direction orthogonal to the X-axis direction in accordance with a signal from the control unit 112. Furthermore, the first position control device 104 also has a function of rotating the ejection head unit 103 around an axis parallel to the Z axis. Here, in the present embodiment, the Z-axis direction is a direction parallel to the vertical direction (that is, the direction of gravitational acceleration).

  The second position control device 108 moves the stage 106 on the ground stage GS in the Y-axis direction according to a signal from the control unit 112. Here, the Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction.

  As described above, the ejection head unit 103 is moved in the X-axis direction by the first position control device 104. Then, the substrate is moved in the Y-axis direction together with the stage 106 by the second position control device 108. As a result, the relative position of the head 114 with respect to the substrate changes. More specifically, by these operations, the ejection head unit 103, the head 114, or the nozzle 118 (see FIG. 2) maintains a predetermined distance in the Z-axis direction with respect to the substrate while maintaining the X-axis direction and the Y-axis. Move relatively in the axial direction, that is, scan relatively. “Relative movement” or “relative scanning” means that at least one of the side on which the liquid material 111 is discharged and the side on which the discharged material lands (discharged part) moves relative to the other. .

  The control unit 112 is configured to receive ejection data representing a relative position at which droplets of the liquid material 111 are to be ejected from an external information processing apparatus. The control unit 112 stores the received discharge data in an internal storage device, and controls the first position control device 104, the second position control device 108, and the head 114 in accordance with the stored discharge data. To do. The ejection data is data for applying the liquid material 111 in a predetermined pattern on the substrate. In the present embodiment, the ejection data has the form of bitmap data.

The droplet discharge device 1 having the above configuration moves the nozzle 118 (see FIG. 2) of the head 114 relative to the substrate according to the discharge data, and also supplies the liquid material 111 from the nozzle 118 toward the discharge target portion. Discharge. The relative movement of the head 114 by the droplet discharge device 1 and the discharge of the liquid material 111 from the head 114 may be collectively referred to as “application scanning” or “discharge scanning”.
The light irradiation device 140 is a device that irradiates the liquid material 111 applied to the substrate with ultraviolet light. The control unit 112 controls ON / OFF of the ultraviolet irradiation of the light irradiation device 140.

  As shown in FIGS. 2A and 2B, the head 114 in the droplet discharge device 1 is an inkjet head having a plurality of nozzles 118. Specifically, the head 114 includes a diaphragm 126, a plurality of nozzles 118, a nozzle plate 128 that defines openings of the plurality of nozzles 118, a liquid pool 129, a plurality of partition walls 122, and a plurality of cavities. 120 and a plurality of vibrators 124.

The liquid pool 129 is located between the diaphragm 126 and the nozzle plate 128. The liquid pool 129 is always filled with the liquid material 111 supplied from an external tank (not shown) through the hole 131. The The plurality of partition walls 122 are located between the diaphragm 126 and the nozzle plate 128.
The cavity 120 is a part surrounded by the diaphragm 126, the nozzle plate 128, and the pair of partition walls 122. Since the cavities 120 are provided corresponding to the nozzles 118, the number of the cavities 120 and the number of the nozzles 118 are the same. The liquid material 111 is supplied from the liquid pool 129 to the cavity 120 through the supply port 130 positioned between the pair of partition walls 122. In the present embodiment, the nozzle 118 has a diameter of about 27 μm, for example.

Now, each of the plurality of vibrators 124 is positioned on the diaphragm 126 so as to correspond to each cavity 120. Each of the plurality of vibrators 124 includes a piezoelectric element 124C and a pair of electrodes 124A and 124B that sandwich the piezoelectric element 124C. When the control unit 112 applies a driving voltage between the pair of electrodes 124A and 124B, the droplet D of the liquid material 111 is ejected from the corresponding nozzle 118. Here, the volume of the material discharged from the nozzle 118 is variable between 0 pl and 42 pl (picoliter). The shape of the nozzle 118 is adjusted so that the liquid material 111 droplets are ejected from the nozzle 118 in the Z-axis direction.
The ejection unit 127 may include an electrothermal conversion element instead of the piezo element. That is, the discharge unit 127 may have a configuration for discharging a material by utilizing thermal expansion of the material by the electrothermal conversion element.

(Multilayer wiring board)
Next, a multilayer wiring board manufactured by applying the electronic substrate manufacturing method according to the present invention will be described with reference to FIG.
A multilayer wiring board (electronic board) 500 shown in FIG. 3 is a board on which a plurality of electronic components, conductive wirings, insulating layers, and the like are stacked.
Details will be described below.

  In the lowermost layer of the multilayer wiring board 500, a chip component (electronic component) 20 having an electrode portion (wiring connection portion) 20a and a chip component (electronic component) 21 having an electrode portion (wiring connection portion) 21a are, for example, epoxy-based. The electrode portions 20a and 21a are embedded in a state of protruding from the resin layer 13 by the resin layer 13 formed of a relatively soft resin material such as resin.

  Examples of the chip components 20 and 21 include resistors, capacitors, and IC chips. In this embodiment, resistors are used as the chip components 20 and capacitors are used as the chip components 21. The chip components 20 and 21 are embedded in the resin layer 13 with the electrode portions 20a and 21a facing upward.

  On the resin layer 13, an insulating layer 60 that includes therein electrode portions 20 a and 21 a and wiring (conductive wiring) 15 connected to the electrode portions 20 a and 21 a is provided. The insulating layer 60 covers a lower insulating film (insulating layer) 60A provided on the resin layer 13 with the lower surface 15a of the wiring 15 as an interface, and covers the wiring 15 on the lower insulating film 60A with the lower surface 15a of the wiring 15 as an interface. The upper insulating film (second insulating layer) 60B is provided. The insulating layer 60A is formed so that the upper surface thereof is substantially flush with the electrode portions 20a and 21a and covers the periphery of the chip components 20 and 21. In FIG. 3, the wiring 15 located on both sides is connected to through holes H1 and H2 penetrating the upper insulating film 60B.

  The insulating films 60A and 60B are both formed by applying an insulating ink (insulating material) using the droplet discharge method by the droplet discharge device 1 described above and curing the insulating ink. is there. As this insulating ink, an acrylic photosensitive resin (more specifically, as a material having photocurability that is cured when light energy is applied and thermosetting that is cured when heat energy is applied, is used. Includes an acrylic resin having photocurability and an epoxy resin having thermosetting properties. This photocurable material may contain a solvent and a resin dissolved in the solvent. Here, the photo-curable material in this case may contain a resin that is itself exposed to increase the degree of polymerization, or contains a resin and a photopolymerization initiator that initiates curing of the resin. You may do it. Moreover, you may contain as a photocurable material the monomer which photopolymerizes and produces | generates an insoluble insulating resin, and the photoinitiator which starts the photopolymerization of the monomer. However, the photocurable material in this case may not contain a photopolymerization initiator as long as the monomer itself has a photofunctional group.

  The wiring 15 and the through holes H <b> 1 and H <b> 2 are formed by discharging conductive ink using a droplet discharge method by the droplet discharge device 1. In this embodiment, a conductive ink containing silver fine particles is used (details will be described later).

  On the insulating layer 60 (upper insulating film 60B), an IC chip (electronic component) 70 having a terminal 72 for external connection and a wiring (second conductive wiring) 61 connected to the wiring 15 through the through hole H1. An insulating layer (third insulating layer) 62 covering the IC chip 70 and the wiring 61; a through hole H3 connected to the wiring 61 and penetrating the insulating layer 62; and the above-described through hole penetrating the insulating layer 62. Part of H2.

The insulating layer 62 is formed of the same material as the insulating films 60A and 60B by using the droplet discharge method by the droplet discharge device 1 described above.
Further, the wiring 61 and the through hole H3 are formed of the same material as that of the wiring 15 and the through holes H1 and H2 by using a droplet discharge method by the droplet discharge device 1.

  On the insulating layer 62, the wiring 63A connected to the terminal 72 and the through hole H2 of the IC chip 70, the wiring 63B connected to the terminal 72 and the through hole H3 of the IC chip 70, and the wirings 63A and 63B are covered. Insulating layer 64, through-hole H4 connected to wiring 63A and passing through insulating layer 64, through-hole H5 connected to wiring 63B and passing through insulating layer 64, and connected to through-hole H5 provided on insulating layer 64 The chip component (electronic component) 24 is provided, and the chip component (electronic component) 25 provided on the insulating layer 64 and connected to the through hole H4 is provided.

The insulating layer 64 is formed of the same material as the insulating layers 60A, 60B, and 62 using the droplet discharge method by the droplet discharge device 1 described above.
Further, the wirings 63A and 63B and the through holes H4 and H5 are formed of the same material as the wirings 15 and 61 and the through holes H1, H2, and H3 by using the droplet discharge method by the droplet discharge device 1.
As the chip components 24 and 25, here, an antenna element and a crystal resonator are mounted, respectively.

(Manufacturing method of multilayer wiring board)
Next, a method for manufacturing the multilayer wiring board (electronic board) 500 will be described with reference to FIGS.
In the present embodiment, the manufacturing method of the present invention is applied to the formation of the resin layer 13 and the lower insulating film 60 </ b> A in the multilayer wiring substrate 500.
Details will be described below.

In the present embodiment, as shown in FIG. 4A, the multilayer wiring board 500 is manufactured using a frame F having a through hole K having a shape corresponding to the outer shape of the multilayer wiring board 500.
First, an adhesive sheet S as a base material having adhesiveness on the surface Sa is pasted on the lower surface (one surface) Fa of the frame F shown in FIG.
Subsequently, the chip components 20 and 21 are mounted using a mounter or the like at a predetermined position on the surface Sa of the adhesive sheet S exposed in the through hole K.
At this time, the chip components 20 and 21 are placed with the electrode portions 20a and 21a contacting each other. Moreover, since the surface Sa of the adhesive sheet S has adhesiveness, the mounted chip components 20 and 21 are positioned at a predetermined position without moving.

  Next, as shown in FIG. 4B, the above-described insulating ink is applied onto the adhesive sheet S in the through hole K by a droplet discharge method. At this time, the insulating ink is applied around the chip parts 20 and 21 as a thin film from which the chip parts 20 and 21 protrude with a thickness sufficiently thinner than the thickness of the chip parts 20 and 21. As a method for applying the insulating ink, a printing method, a dispensing method, or the like may be used in addition to the droplet discharge method.

Subsequently, the applied insulating ink is irradiated with light having a wavelength in the ultraviolet region for a predetermined time to give a predetermined amount of energy, whereby only the acrylic resin is cured and the epoxy resin is in an uncured semi-cured state. At this time, the amount of energy applied to the insulating ink is set to a value smaller than the amount of energy for curing the insulating ink.
Here, the semi-curing of the insulating ink means that the state of the photocurable material contained in the insulating ink is in a state between the discharged state and the completely cured state. In the present embodiment, such an intermediate state is the above-described semi-cured state. In addition, the state at the time of discharge is a state in which the photocurable material has a viscosity that can be discharged from the nozzle 118.
Thereby, as shown in FIG. 4B, a semi-cured lower insulating film 60A is formed.

Next, as shown in FIG. 4C, a resin material is applied and cured by a droplet discharge method so as to surround the periphery of the chip parts 20 and 21 on the lower insulating film 60A in the through hole K, and then the resin is formed. Layer 13 is formed. The resin material may be applied by a printing method, a dispensing method, or the like.
In the present embodiment, the resin layer 13 is formed with a thickness that is substantially flush with the surfaces of the chip components 20 and 21, and the chip components 20 and 21 are embedded.
Thereafter, as shown in FIG. 4D, the adhesive sheet S is peeled off from the lower surface Fa of the frame F, so that the electrode portions 20a and 21a and the lower insulating film 60A of the chip components 20 and 21 are exposed.

  Subsequently, the resin layer 13 in which the chip components 20 and 21 are embedded and the lower insulating film 60A are turned upside down together with the frame F, and as shown in FIG. 5A, on the semi-cured lower insulating film 60A. A wiring 15 is formed. In FIG. 5 and subsequent figures, the illustration of the frame F is omitted for convenience.

More specifically, like the lower insulating film 60A, the wiring 15 is formed by discharging conductive ink using a droplet discharge method by the droplet discharge device 1.
In the present embodiment, the dispersion medium of the silver fine particle dispersion liquid in which silver fine particles having a diameter of about 10 nm are dispersed in an organic solvent is replaced with tetradecane and diluted to have a concentration of 60 wt%, a viscosity of 8 mPa · s, and a surface tension of 0. What was adjusted so that it might become 0.02N / m was used as a conductive ink.

Specifically, by discharging conductive ink onto the electrode portions 20a and 21a of the chip components 20 and 21 and firing, the chip components 20 and 21 are electrically connected to each other as shown in FIG. The Ag wiring (conductive wiring) 15 connected to can be formed.
The dispersion medium is not particularly limited as long as it can disperse silver fine particles and does not cause aggregation. For example, in addition to water, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydro Hydrocarbon compounds such as naphthalene and cyclohexylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis (2- Methoxyethyl) ether, ether compounds such as p-dioxane, propylene carbonate, γ- Butyrolactone, N- methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, can be exemplified polar compounds such as cyclohexanone. Of these, water, alcohols, hydrocarbon compounds, and ether compounds are preferred from the viewpoints of fine particle dispersibility and dispersion stability, and ease of application to the droplet discharge method (inkjet method). More preferred dispersion media include water and hydrocarbon compounds. Moreover, it is preferable that the viscosity of a dispersion liquid is 1 mPa * s or more and 50 mPa * s or less, for example. When the liquid material is ejected as droplets using the inkjet method, if the viscosity is less than 1 mPa · s, the nozzle periphery is easily contaminated by the outflow of ink, and if the viscosity is greater than 50 mPa · s, This is because the clogging frequency of the liquid becomes high and it becomes difficult to smoothly discharge the droplets.

In order to adjust the surface tension, a small amount of a surface tension regulator such as a fluorine-based, silicone-based, or non-ionic-based material may be added to the dispersion liquid in a range that does not significantly reduce the contact angle with the substrate. The nonionic surface tension modifier improves the wettability of the liquid to the substrate, improves the leveling property of the film, and helps prevent the occurrence of fine irregularities in the film. The surface tension modifier may contain an organic compound such as alcohol, ether, ester, or ketone, if necessary.
Through the above steps, the electronic components 20 and 21 are embedded in the resin layer 13 and the lower insulating film 60A, and the single-layer wiring board 100 having the wiring 15 connected to the electrode portions 20a and 20b is manufactured.

  Next, as shown in FIG. 5B, the same insulating ink as the material for forming the lower insulating film 60A is applied by the droplet discharge method so as to cover the wiring 15 on the lower insulating film 60A, and further in the ultraviolet region. The upper insulating film 60B is formed in a semi-cured state by applying a predetermined amount of energy by irradiating light having a wavelength of for a predetermined time.

The insulating ink is applied so as to surround the through holes H1 and H2, and holes corresponding to the through holes H1 and H2 are formed. Then, after forming the semi-cured insulating film 60B by irradiating with ultraviolet light, the through holes H1 and H2 are formed by discharging conductive ink into the holes of the insulating film 60B using a droplet discharge method. .
Thereafter, the insulating films 60A and 60B, the wiring 15, and the through holes H1 and H2 are cured by heating together. At this time, in the insulating films 60A and 60B, the uncured epoxy resin is cured, so that it is completely cured together with the acrylic resin that has already been cured by light irradiation.

  Next, as shown in FIG. 6A, the wiring 61 connected to the wiring 15 and the chip component 20 through the through hole H1 is formed on the upper insulating film 60B (insulating layer 60), and the IC chip 70 is also formed. Is installed. Similar to the wiring 15 and the through holes H1 and H2 of the wiring 61, the wiring 61 is formed by a droplet discharge method.

  Thereafter, as shown in FIG. 6B, the above-described insulating ink is applied on the insulating film 60B by the droplet discharge method so as to cover the IC chip 70 and the wiring 61 so that the terminal 72 protrudes. Then, the insulating layer 62 having the lower surfaces of the wirings 63A and 63B as an interface is formed by irradiating ultraviolet light into a semi-cured state. The insulating ink is formed so as to surround the through hole H2 connected to the wiring 15 and the through hole H3 connected to the wiring 61. Thereby, the IC chip 70 is embedded in the insulating layer 62.

  The through holes H2 and H3 are formed by applying the same material as the wirings 15 and 61 by the droplet discharge method, and the wirings 63A and 63B connected to the terminal 72 are formed on the insulating layer 62 by the droplet discharge method. Form. At this time, the wirings 63A and 63B are connected to the terminal 72 of the IC chip 70 and the through holes H2 and H3, respectively.

Then, as shown in FIG. 3, the wiring 63 is covered on the insulating layer 62, the above-described insulating ink is applied by a droplet discharge method, and is irradiated with ultraviolet light so as to be in a semi-cured state. An insulating layer 64 having the lower surface of the interface as an interface is formed. Then, other chip components 24 and 25 are mounted on the insulating layer 64 through the through-hole holes H4 and H5. These through holes H4 and H5 are formed by the same material and procedure as the above-described through holes H2 and H3. The insulating layer 64 and the through holes H4 and H5 are also formed using a droplet discharge method.
Here, as the chip components 24 and 25, here, an antenna element and a crystal resonator were mounted, respectively.

  Thereafter, the insulating layers 62 and 64, the wirings 61, 63A and 63B, and the through holes H2 to H5 are cured by heating together. At this time, in the insulating layers 62 and 64, the uncured epoxy resin is cured, so that the insulating layers 62 and 64 are completely cured together with the acrylic resin that has already been cured by light irradiation.

The multilayer wiring board 500 can be formed by the above steps.
In order to separate the multilayer wiring board 500 from the frame F, for example, a method of punching the multilayer wiring board 500 to remove the mold from the frame F, a method of removing the frame F by cutting, etc. A method of separating a frame structure after forming the multilayer wiring board 500 by using a plurality of frame structures that can be separated and integrated can be employed.

  As described above, in this embodiment, since most of the chip components 20 and 21 are covered with the soft resin layer 13, it is possible to suppress the occurrence of cracks due to curing shrinkage. An insulating layer 60 composed of a lower insulating film 60A and an upper insulating film 60B is provided including the lower surfaces of the electrode parts 20a and 21a of the chip components 20 and 21 and the wiring 15, and is simultaneously cured by heating. Therefore, it is possible to make a state in which no stress remains between the cured insulating films 60A and 60B. Therefore, in the present embodiment, it is possible to obtain the multilayer wiring board 500 that is a structurally stable electronic board in which cracks are unlikely to occur.

  In addition, in the present embodiment, the lower insulating film 60A and the resin layer 13 are stacked around the chip components 20 and 21 placed on the adhesive sheet S, and then the adhesive sheet S is peeled off. The surface of the electrode portions 20a, 21a and the lower insulating film 60A can be easily obtained with a smooth and flush wiring substrate 100, and productivity can be improved. In this way, the outer shape of the wiring board 100 (multilayer wiring board 500) can be easily defined by the through hole K of the frame F, and the wiring board 100 (multilayer wiring board 500) having a desired shape can be easily obtained. be able to.

Further, in this embodiment, all the manufacturing processes of the wiring board 100 and the multilayer wiring board 500 can be performed by a droplet discharge method, and the productivity can be greatly improved.
In this embodiment, since the insulating ink is applied by a droplet discharge method, the adhesive can be easily patterned without using a mask, a resist, or the like, such as a printing method or a photolithography method. In addition, since the consumed adhesive does not waste, it can contribute to cost reduction. Furthermore, in this embodiment, since the insulating ink is made into a semi-cured state by applying light energy, the semi-curing process is easy, and for example, by using a mask or the like, the irradiation range of the ultraviolet light can be easily specified. It is possible to easily pattern the region to be semi-cured.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the insulating films 60A and 60B are cured, and then the insulating layers 62 and 64 are formed and cured again. However, the present invention is not limited to this. For example, all insulating layers The film may be formed in a semi-cured state and finally heated and cured at the end. In this case, heating / curing steps can be reduced, and productivity can be improved.

In the above embodiment, the through hole K of the frame F has been described as extending in parallel to the stacking direction of the multilayer wiring board 500. However, the present invention is not limited to this. For example, as shown in FIG. The electrode parts 20a and 21a of the components 20 and 21 and the lower insulating film 60A may be formed in a tapered shape with a diameter decreasing from the lower surface Fa side to the upper surface (other surface) Fb side.
In this configuration, when the resin layer 13 and the lower insulating film 60A are pushed downward and move even slightly, the resin layer 13 and the lower insulating film 60A are separated from the through hole K and can be easily detached from the frame F. In particular, it is preferable that the pressed side is a surface opposite to the surface on which the resin layer 13 and the lower insulating film 60A are provided, so that damage to the wiring and the like is avoided.
Further, the frame F is not necessarily used, and may be a procedure for forming the multilayer wiring substrate 500 only by patterning by a droplet discharge method.

  Further, in the above embodiment, the chip parts 20 and 21 are both placed with the electrode portions 20a and 20b in contact with the adhesive sheet S so that the electrode portions 20a and 20b are arranged flush with each other. However, for example, when the chip components 20 and 21 (electrode portions 20a and 20b) are arranged with a step, the electrode portions 20a and 20b are brought into contact with the adhesive sheet S for one of the chip components 20 and 21. The other of the chip components 20 and 21 can be easily handled by placing the electrode portions 20a and 20b in contact with the spacer placed on the adhesive sheet S. is there.

  Furthermore, in the above-described embodiment, the present invention is applied to the multilayer wiring board 500. However, the present invention is not limited to this, and may be applied only to the wiring board 100 described above.

It is a schematic diagram of the droplet discharge apparatus used for manufacture of an electronic substrate. (A) And (b) is a schematic diagram of the head in a droplet discharge device. It is sectional drawing which shows schematic structure of a multilayer wiring board. It is process drawing which shows the procedure which forms a multilayer wiring board. It is process drawing which shows the procedure which forms a multilayer wiring board. It is process drawing which shows the procedure which forms a multilayer wiring board. It is sectional drawing which shows another form of a flame | frame.

Explanation of symbols

  F ... Frame, Fa ... Lower surface (one surface), Fb ... Upper surface (other surface), S ... Adhesive sheet (base material), Sa ... Front surface, 1 ... Droplet discharge device, 13 ... Resin layer, 15 ... Wiring (conductive wiring) ), 24, 25 ... chip parts (electronic parts), 60A ... lower insulating film (insulating layer), 60B ... upper insulating film (second insulating layer), 61 ... wiring (second conductive wiring), 62 ... insulating layer ( (Third insulating layer), 500 ... multilayer wiring board (electronic board)

Claims (6)

A method of manufacturing an electronic substrate having an electronic component and a conductive wiring connected at a wiring connection portion of the electronic component,
Placing the electronic component in contact with the wiring connection portion on the surface of the substrate; and
Applying an insulating material having a photocurable property and a thermosetting property to a thickness thinner than the thickness of the electronic component around the electronic component on the surface of the base material, and forming an insulating layer;
Forming a resin layer for embedding the electronic component on the insulating layer;
And a step of peeling the base material from the electronic component and forming the conductive wiring on the insulating layer. In the manufacturing method of the electronic substrate of Claim 1,
Forming the insulating layer in a semi-cured state;
Coating the insulating material on the insulating layer so as to cover the conductive wiring, and forming a semi-cured second insulating layer; and
And a step of collectively heating and curing the semi-cured insulating layer and the second insulating layer. In the manufacturing method of the electronic substrate of Claim 2,
Forming a second conductive wiring provided on the second insulating layer and electrically connected to the conductive wiring; and forming a third insulating layer formed of the insulating material and covering the second conductive wiring. And a method of manufacturing an electronic substrate. In the manufacturing method of the electronic substrate in any one of Claim 1 to 3,
The method of manufacturing an electronic substrate, wherein the surface of the base material has adhesiveness. In the manufacturing method of the electronic substrate in any one of Claim 1 to 4,
On one surface of the frame having a through hole of a predetermined shape, the step of covering the through hole and pasting the base material,
A method for manufacturing an electronic substrate, comprising: mounting the electronic component on a surface of the base material exposed in the through hole. In the manufacturing method of the electronic substrate of Claim 5,
The method of manufacturing an electronic substrate, wherein the through hole is formed in a tapered shape whose diameter decreases from the one surface side toward the other surface side.

Images