JP5561683B2 - Component built-in board - Google Patents

Description

  The present invention relates to a component built-in substrate in which an electronic component is built.

  As a component-embedded substrate in which an electronic component such as a semiconductor component is embedded, for example, an electronic device using a multilayer printed wiring board disclosed in Patent Document 1 is known. This electronic device has a multilayer structure in which electronic components are built in between printed wiring boards, and has a characteristic of having a certain degree of flexibility while ensuring an arbitrary layer spacing while progressing in thinning.

JP 2007-80857 A

  However, in the electronic device of the prior art disclosed in Patent Document 1, various problems such as bending and bending depending on the mechanical strength and bendability of each layer of the wiring board occur as the film thickness decreases. Further improvement in mechanical strength and flexibility is required.

  An object of the present invention is to provide a component-embedded substrate that solves the above-described problems of the prior art and has improved mechanical strength and flexibility.

  The component-embedded substrate according to the present invention includes a component-embedded substrate in which a plurality of printed wiring substrates each having a wiring pattern and a via formed on a resin substrate are stacked in the stacking direction via an adhesive layer and an electronic component is embedded. And it has a notch which is formed in the printed wiring substrate and the adhesion layer, and extends between the electronic parts in the lamination direction and the surface direction of the printed wiring board.

  According to the component-embedded substrate according to the present invention, the cut-in portion is formed in the printed wiring base material and the adhesive layer and extends between the electronic components in the stacking direction and the surface direction of the printed-wiring substrate. The flexibility of the substrate is improved. As a result, due to the difference in bending rigidity between part of the printed wiring board near the notch (hereinafter referred to as the bent portion) and other portions, the bent portion almost bears the distortion caused by bending, and the electronic components other than the bent portion are arranged. Almost no distortion occurs in the part. Therefore, the mechanical strength in the vicinity of the electronic component can be kept high.

  The component built-in substrate according to one embodiment of the present invention may include an elastic member filled in the cut portion. With this elastic member, the component built-in board can be returned to the normal state before the external force is applied without applying an external force after the component built-in board is bent.

  In the component-embedded substrate according to the embodiment of the present invention, silicone rubber or fluororubber can be used as the elastic member.

  According to the present invention, it is possible to provide a component-embedded substrate with improved mechanical strength and flexibility.

It is a top view which shows the structure of the component built-in board | substrate which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the component built-in board | substrate concerning 1st Embodiment. It is a flowchart which shows the manufacturing process of the component built-in board | substrate of 1st Embodiment. It is sectional drawing which shows the component built-in board | substrate in the manufacturing process of 1st Embodiment. It is sectional drawing which shows the structure of the component built-in board | substrate which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the manufacturing process of the component built-in board | substrate of 2nd Embodiment. It is sectional drawing which shows the component built-in board | substrate in the manufacturing process of 2nd Embodiment. It is sectional drawing which shows the structure of the component built-in board | substrate concerning the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the component built-in board | substrate concerning the 4th Embodiment of this invention. It is sectional drawing which shows the structure of the component built-in board | substrate concerning the 5th Embodiment of this invention. It is sectional drawing which shows the structure of the component built-in board | substrate concerning the 6th Embodiment of this invention. It is sectional drawing which shows the structure of the component built-in board | substrate concerning the 7th Embodiment of this invention.

  Hereinafter, a component-embedded substrate and a manufacturing method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
First, the configuration of the component-embedded substrate according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic top view of a component-embedded substrate according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.

  As shown in FIG. 2, the component-embedded substrate according to the first embodiment includes a first printed wiring substrate 10, a second printed wiring substrate 20, and a third layer that are stacked together by thermocompression bonding via an adhesive layer 9. The printed wiring board 30, the fourth printed wiring board 40, and the fifth printed wiring board 50 are included. The adhesive layer 9 is made of, for example, an epoxy-based or acrylic-based thermosetting or thermoplastic adhesive.

  Further, the component-embedded substrate is embedded in the opening 39a formed in the third resin base 31 of the third printed wiring base 30 while being sandwiched between the second and fourth printed wiring bases 20 and 40. IC chip 60 is provided. Furthermore, the component-embedded substrate is provided with first and fourth printed wirings in openings 29 and 39b formed in the second and third resin base materials 21 and 31 of the second and third printed wiring base materials 20 and 30, respectively. It has a passive component 70 built in a state sandwiched between the base materials 10 and 40.

  The first to fifth printed wiring substrates 10 to 50 are respectively a first resin substrate 11, a second resin substrate 21, a third resin substrate 31, a fourth resin substrate 41, and a fifth resin substrate 51. And signal wirings (wiring patterns) 12, 22, 32, 42, 52 formed on the surfaces of the first to fifth resin base materials 11 to 51. The signal wirings 12, 22, 42, 52 are formed on one surface of the first, second, fourth, and fifth resin base materials 11, 21, 41, 51, and the signal wiring 32 is a third resin base material. 31 is formed on both sides.

  The first, second, fourth and fifth printed wiring substrates 10, 20, 40, 50 are formed based on a single-sided copper-clad laminate (single-sided CCL), and the third printed wiring substrate 30 is a double-sided copper-clad It is formed based on a laminated board (double-sided CCL).

  The 1st-5th resin base materials 11-51 are each comprised by the resin film about 25 micrometers thick, for example. Here, as the resin film, for example, a resin film made of polyimide, polyolefin, liquid crystal polymer, or the like, a resin film made of a thermosetting epoxy resin, or the like can be used. The signal wirings 12 to 52 are formed by patterning a conductive material such as copper foil.

  The component-embedded substrate can be thinned by the first to fifth resin base materials 11 to 51 and the signal wirings 12 to 52 as described above.

  The first, second, fourth and fifth printed wiring substrates 10, 20, 40 and 50 are formed on the first, second, fourth and fifth resin substrates 11, 21, 41 and 51, respectively. Signal vias 14, 24, 44, 54 filled in the formed via holes. The signal via 14 electrically connects the signal wirings 12 and 22, and the signal via 24 electrically connects the signal wirings 22 and 32. The signal via 44 electrically connects the signal wirings 32 and 42, and the signal via 54 electrically connects the signal wirings 42 and 52. The signal via 24 is electrically connected to the IC chip 60, and the signal via 44 is electrically connected to the passive component 70. The signal wirings 32 formed on both surfaces of the third resin base 31 are electrically connected to each other via signal vias (not shown) formed by plating in the via holes of the third resin base 31. Has been.

  The signal vias 14, 24, 44, and 54 are made of conductive paste filled in the via holes, respectively. The conductive paste is, for example, at least one kind of low electrical resistance metal particles selected from nickel, gold, silver, copper, aluminum, iron and the like, and at least one kind selected from tin, bismuth, indium, lead and the like. And a metal paste having a melting point and a paste in which a binder component mainly composed of epoxy, acrylic, urethane or the like is mixed.

  The conductive paste thus configured has a characteristic that the contained low melting point metal can be melted at 200 ° C. or less to form an alloy, and in particular, can form an intermetallic compound with copper or silver. Prepare. Note that the conductive paste can also be formed of a nanopaste in which fillers such as gold, silver, copper, and nickel having a nanometer particle size are mixed with the binder component as described above.

  In addition, the conductive paste can also be composed of a paste in which metal particles such as nickel are mixed with the binder component as described above. In this case, the conductive paste has a characteristic that electrical connection is made when metal particles come into contact with each other. As a method for filling the via hole with the conductive paste, for example, a printing method, a spin coating method, a spray coating method, a dispensing method, a laminating method, and a method using these in combination can be used.

  And this embodiment has the notch part 81 formed by notching the 1st-3rd printed wiring base materials 10-30 in the lamination direction, as shown in FIG.1 and FIG.2. As shown in FIG. 1, the cut portions 81 are formed in, for example, a lattice shape so as to extend in the surface direction of the first to third printed wiring substrates 10, 20, and 30. Moreover, the notch part 81 is provided between these, for example so that electronic components, such as IC chip 60 and the passive component 70, may be avoided. The cut portion 81 is formed corresponding to an expected bending direction, and compressive stress generated when bending is applied to the fourth and fifth printed wiring substrates 40 and 50. Specifically, the cut portion 81 is provided at a position corresponding to the openings 29 and 39 b, and the adhesive layer 9 is provided adjacent to the cut portion 81. The cut portion 81 extends from the upper surface of the first resin base material 11 to the upper surface of the fourth resin base material 41.

  Due to the above-described cut portion 81, the flexibility of the component-embedded substrate is improved. Also, due to the difference in bending rigidity between the first to fifth printed wiring base materials 10 to 50 in the vicinity of the cut portion 81 (hereinafter, the bent portion) and other portions, the bent portion almost bears the distortion caused by the bending, Almost no distortion occurs in the portion other than the bent portion. Thereby, this embodiment can keep the mechanical strength in the vicinity of the IC chip 60 and the passive component 70 high.

  The cut portion 81 may be formed so as to leave at least one of the first to fifth resin base materials 11 to 51 and any one of the signal wirings 12 to 52. In addition, the depth of the cut portion 81 is desirably 1/2 or more of the total thickness of the component-embedded substrate.

  Next, a method for manufacturing the component-embedded substrate according to the first embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the manufacturing process of the component built-in board, and FIG. 4 is a cross-sectional view showing the component built-in board in the manufacturing process.

  First, as shown to Fig.4 (a), the 1st-5th printed wiring base materials 10-50, IC chip 60, and the passive component 70 are positioned and laminated | stacked (step S101 of FIG. 3). At the time of lamination, for example, using a vacuum press, thermocompression bonding is performed by heating and pressing in a reduced pressure atmosphere of 1 kPa or less. By thermocompression bonding, the conductive paste filled in the via hole is cured and alloyed simultaneously with the curing of the adhesive layers 9 between the layers and the resin base materials 21 and 31.

  Then, as shown in FIG.4 (b), the notch part 81 is formed by penetrating the 1st-3rd printed wiring base materials 10-30 with a laser (step S102 of FIG. 3). In step S102, dicing may be used instead of the laser.

[Second Embodiment]
FIG. 5 is a sectional view showing the structure of a component-embedded substrate according to the second embodiment of the present invention. In the component built-in substrate according to the second embodiment, the cut portion 81 is formed without performing a cut operation in a later process by stacking pieces of the printed wiring base material. The second and third resin base materials 21 and 31 are provided adjacent to the cut portion 81 between the cut portion 81 and the openings 29 and 39b. In this respect, the second embodiment is structurally different from the first embodiment. The 2nd and 3rd resin base materials 21 and 31 adjacent to the notch part 81 function as a spacer between the 1st resin base material 11 and the 4th resin base material 41, and raise the mechanical strength of a component built-in board. . With these structures, the second embodiment can be manufactured according to the manufacturing process described below. Note that the second embodiment also has the same effect as the first embodiment.

  Next, a method for manufacturing a component-embedded substrate according to the second embodiment will be described with reference to FIGS. FIG. 6 is a flowchart showing the manufacturing process of the component built-in board, and FIG. 7 is a cross-sectional view showing the component built-in board in the manufacturing process.

  First, as shown to Fig.7 (a), the 1st-5th printed wiring base materials 10-50, IC chip 60, and the passive component 70 are positioned (step S201 of FIG. 6). In this step S201, each of the first to third printed wiring substrates 10 to 30 is cut into pieces 10A to 10E, 20A to 20E, and 30A to 30E. The fragments 10A to 30A, 10B to 30B, 10C to 30C, 10D to 30D, and 10E to 30E are arranged with a predetermined interval, and the interval becomes the cut portion 81. The fragments 20B and 20D have an opening 29. The fragment 30C has an opening 39a, and the fragments 30B and 30D have an opening 39b.

  Next, lamination is performed as shown in FIG. 7B (step S202 in FIG. 6). In this step S202, since dicing or laser is not used unlike the manufacturing process of the first embodiment, burrs and smears do not occur.

[Third Embodiment]
FIG. 8 is a cross-sectional view showing the structure of a component-embedded substrate according to the third embodiment of the present invention. The component-embedded substrate according to the third embodiment is different from the first embodiment in that it has an elastic member 82 filled in a cut portion 81 as shown in FIG. The elastic member 82 is preferably heat resistant rubber, and the heat resistant temperature is preferably 300 ° C. or higher. For example, the heat resistant rubber is made of silicone rubber or fluoro rubber. The elastic member 82 has an elastic modulus of 1 to 100 MPa, for example.

  The elastic member 82 can return the component built-in substrate to a normal state before applying the external force without applying an external force after the component built-in substrate is bent. For example, if the elastic member 82 is made of a material that cures at room temperature, warpage of the component-embedded substrate at room temperature can be suppressed. Note that the third embodiment also has the same effect as the first embodiment.

[Fourth Embodiment]
FIG. 9 is a cross-sectional view showing the structure of a component-embedded substrate according to the fourth embodiment of the present invention. As shown in FIG. 9, the component-embedded substrate according to the fourth embodiment is the second embodiment in that it has an elastic member 82 filled in the cut portion 81 of the second embodiment shown in FIG. Is different. Thereby, 4th Embodiment has an effect similar to 2nd and 3rd Embodiment.

[Fifth Embodiment]
FIG. 10 is a cross-sectional view showing the structure of a component built-in substrate according to the fifth embodiment of the present invention. The component-embedded substrate according to the fifth embodiment is different from the first embodiment in that it has two types of front and back notches 81a and 81b, as shown in FIG. The cut portion 81a is formed so as to penetrate the first and second printed wiring substrates 10 and 20, and the cut portion 81b is formed so as to penetrate the fourth and fifth printed wiring substrates 40 and 50. . The notches 81a and 81b are formed opposite to each other in the stacking direction via the third printed wiring substrate 30. The notches 81a and 81b are provided between the IC chip 60, the passive component 70, and the signal vias 14, 24, 44, and 54.

  The first embodiment corresponds to only bending in one direction of the component-embedded substrate. On the other hand, the fifth embodiment can cope with bending in two directions of the component-embedded substrate by the notches 81a and 81b. Note that the fifth embodiment also has the same effect as the first embodiment.

[Sixth Embodiment]
FIG. 11 is a cross-sectional view showing the structure of a component-embedded substrate according to the sixth embodiment of the present invention. As shown in FIG. 11, the component-embedded substrate according to the sixth embodiment includes notches 81a and 81b, as in the fifth embodiment. However, in the sixth embodiment, the cut portions 81a and 81b are formed at different positions in the surface direction of the first to fifth printed wiring substrates 10 to 50. In this respect, the sixth embodiment is different from the fifth embodiment. Even in the sixth embodiment, the same effects as in the fifth embodiment can be obtained.

[Seventh Embodiment]
FIG. 12 is a cross-sectional view showing the structure of a component-embedded substrate according to the seventh embodiment of the present invention. As shown in FIG. 12, the component-embedded substrate according to the seventh embodiment is obtained by filling the cut portions 81a and 81b of the fifth embodiment with an elastic member 82. Thereby, 7th Embodiment has an effect similar to 3rd and 5th Embodiment.

Claims (5)

A component-embedded substrate in which a plurality of printed wiring substrates, in which a wiring pattern and vias are formed on a resin substrate, are laminated in a laminating direction via an adhesive, and an electronic component is built-in,
Have a notch extending in the plane direction of the stacking direction and the printed circuit board between the printed circuit substrate and the formed in the adhesive layer wherein each of the electronic components,
The cut portion is formed by continuously penetrating the printed wiring substrate from at least one of the stacking directions while leaving a part of the plurality of printed wiring substrates. Component built-in board characterized by The component built-in board according to claim 1, further comprising an elastic member filled in the cut portion. The component built-in board according to claim 2, wherein the elastic member is a heat-resistant rubber. The component built-in substrate according to claim 2, wherein the elastic member is made of silicone rubber or fluororubber. 5. The component-embedded substrate according to claim 1, wherein the cut portions are formed on the front and back sides of the plurality of printed wiring base materials.

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