JP2014135352A - Method of manufacturing laminated wiring board and laminated wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lamination of both layers without causing a gap between a plurality of conductors, in a laminated wiring board where a first layer and a second layer are laminated, and a plurality of conductors becoming interlayer wiring are formed between both layers.SOLUTION: A plurality of conductors 30 are arranged on one surface 11 of a first layer 10 while spaced apart from each other, and a heat dissipation member 40 harder than a second layer 20 and having a thermal conductivity larger than that of the second layer 20 is mounted on the conductor 30 independently for every plurality of conductors 30, thus brings about a state where the heat dissipation members 40 on the conductor 30 are separated from each other between the plurality of conductors 30. Subsequently, one surface 21 of the second layer 20 is made to face the one surface 11 of the first layer 10, and then both layers 10, 20 are pressed thus sticking the one surfaces 11, 21 of both layers 10, 20 while embedding the plurality of conductors 30 and the heat dissipation members 40 in the second layer 20.

Description

  The present invention is formed by laminating at least two layers of a first layer and a second layer made of a resin, and providing a plurality of conductors serving as interlayer wirings between the two layers. The present invention relates to a multilayer wiring board and a method for manufacturing such a multilayer wiring board.

  Generally, in this type of laminated wiring board, at least two layers of a first layer and a second layer made of a resin are laminated, and a plurality of conductors serving as interlayer wirings are formed between the two layers. It has been proposed.

  Such a laminated wiring board is generally formed as follows. A plurality of conductors are spaced apart on one surface of the first layer, and in this state, one surface of the second layer is opposed to one surface of the first layer, and both the layers are pressed. As a result, one surface of both the layers is bonded together while the plurality of conductors are embedded in the second layer.

  In recent years, there is an increasing demand for high heat dissipation in such a multilayer wiring board, and there is a demand for improvement in heat dissipation of conductors. In contrast, conventionally, a material having a thermal conductivity of about 10 W / m · K, for example, has been proposed as a highly thermally conductive resin material for a substrate (see Patent Document 1). This highly heat-conductive resin material contains a filler having electrical insulation and heat conductivity in the resin for high heat conductivity.

JP 2001-348488 A

  The present inventor has conducted a trial examination on the case where the second layer is made of the high thermal conductivity resin material in the multilayer wiring board. As a result, it was found that problems as shown in FIGS. 9 and 10 occur.

  The multilayer wiring board as the prototype is created as follows. First, as shown in FIG. 9, a plurality of conductors 30 are arranged on one surface 11 of the first layer 10 so as to be separated from each other, and in this state, one surface 21 of the second layer 20 is disposed on the first layer 10. It is made to oppose the one surface 11.

  Next, as shown in FIG. 10, the two layers 10, 20 are pressed so that the plurality of conductors 30 are embedded in the second layer 20. The surfaces 11 and 21 are bonded together. Thereafter, the resin is cured and the substrate is completed. Thereby, the heat radiation of the conductor 30 is performed through the second layer 20 made of a high thermal conductivity material.

  Here, although the 2nd layer 20 is comprised with the above-mentioned highly heat conductive resin material, the said material has much filler content contained in resin compared with a general resin material. Therefore, the second layer 20 is harder than a general layer, and the embedding property of the plurality of conductors 30 is deteriorated during pressing.

  Then, as shown in FIG. 10, when the first layer 10 and the second layer 20 are stacked by pressing, the degree of filling of the second layer 20 is insufficient between the plurality of conductors 30. Thus, the gap K is generated. Such a gap K is undesirable because it leads to a short circuit between the conductors 30 having different potentials.

  The present invention has been made in view of the above problems, and a plurality of layers of at least two layers of a first layer and a second layer are laminated, and a plurality of layers serving as interlayer wirings between the two layers are provided. An object of the present invention is to realize a configuration in which both layers are laminated without causing a gap between a plurality of conductors in a laminated wiring board formed with conductors.

In order to achieve the above object, in the invention described in claim 1, at least two layers of the first layer (10) and the second layer (20) made of resin are laminated, A method for manufacturing a laminated wiring board, wherein a plurality of conductors (30) serving as interlayer wirings are formed between both layers of a layer and a second layer,
A preparation step of preparing the first layer and the second layer, a conductor arrangement step of arranging a plurality of conductors (30) separately on one surface (11) of the first layer, and a second layer By mounting the heat radiating member (40) which is harder and has a higher thermal conductivity on the conductor independently for each of the plurality of conductors, the heat radiating members on the conductor are separated from each other between the plurality of conductors. The heat radiation member step to be in a state and one surface (21) of the second layer are made to face one surface of the first layer, and both the layers are pressed, whereby a plurality of conductors and heat radiation members are attached to the second layer. And a pressing step of bonding the surfaces of the two layers together while being embedded.

  According to this, a plurality of conductors that are interlayer wirings that require heat dissipation are provided in the first layer, and a heat dissipation member that is harder than the second layer is disposed so that the heat dissipation members are separated from each other between the conductors. Since both the layers are pressed in a state of being provided for each conductor, the soft second layer reaches one surface of the first layer while pushing the heat radiating member between the conductors by this pressing. You can fill the gap. Therefore, according to the present invention, it is possible to realize a configuration in which the first layer and the second layer are stacked without generating a gap between a plurality of conductors that are interlayer wirings that require heat dissipation. .

  Moreover, in invention of Claim 2, in the manufacturing method of Claim 1, as a 2nd layer and a heat radiating member, it consists of the same thermosetting resin material, and the said thermosetting resin The content of the filler having electrical insulation and thermal conductivity contained in the material is different, and further, the heat radiating member has a higher filler content. A curing step is performed in which the layer 2 and the heat dissipation member are heated and cured.

  According to this, since the second layer and the heat radiating member are made of the same thermosetting resin material, it is possible to strengthen the adhesion between the interfaces of the two after the curing step.

  In the invention according to claim 3, in the manufacturing method according to claim 1 or 2, in the pressing step, the heat dissipation member is exposed on the other surface (22) opposite to the one surface of the second layer. It is characterized by pressing until.

  According to this, since the heat radiating member is exposed on the other surface of the second layer, it is easy to thermally connect the heat radiating member and the other member on the other surface side.

In the invention described in claim 4, the first layer (10), the second layer (20) made of resin laminated on one surface (11) of the first layer, and the second layer are embedded. The plurality of conductors (30) configured as interlayer wirings and a plurality of conductors (30) embedded in the second layer are disposed on one surface of the first layer in a separated state. A heat dissipating member (40) made of a material harder than the second layer and having a higher thermal conductivity provided on the conductor,
The heat dissipating member is mounted independently for each of the plurality of conductors, so that the heat dissipating members on the conductor are separated from each other between the plurality of conductors, and the second layer is provided between the conductors. Between the conductors by reaching one surface of the first layer.

  Since the multilayer wiring board of the present invention can be appropriately manufactured by the manufacturing method according to claim 1, according to the present invention, there is a gap between a plurality of conductors that are interlayer wirings that require heat dissipation. A structure in which the first layer and the second layer are stacked can be realized without causing the above.

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a schematic cross-sectional view of a multilayer wiring board according to a first embodiment of the present invention. It is a schematic sectional drawing which shows the manufacturing method of the laminated wiring board shown by FIG. FIG. 3 is a schematic cross-sectional view showing a method for manufacturing the laminated wiring board following FIG. 2. FIG. 3 is a schematic plan view illustrating an example of a planar shape of a conductor on one surface side of a first layer in FIG. 2. It is a schematic plan view which shows the state which has arrange | positioned the heat radiating member further on the conductor in FIG. It is a schematic sectional drawing which shows the principal part of the laminated wiring board concerning 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the laminated wiring board concerning 3rd Embodiment of this invention. It is a schematic sectional drawing which shows the laminated wiring board concerning 4th Embodiment of this invention. It is a schematic sectional drawing which shows the manufacturing method of the multilayer wiring board as a prototype of this inventor. It is a schematic sectional drawing which shows the manufacturing method of the multilayer wiring board as a prototype following FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
The multilayer wiring board according to the first embodiment of the present invention will be described with reference to FIG. The multilayer wiring board S1 is applied as a part of an electronic device or the like mounted on an automobile, for example.

  The multilayer wiring board S1 of the present embodiment is roughly configured to include two layers, a first layer 10 and a second layer 20 made of a resin laminated on one surface 11 of the first layer 10. ing. Here, the one surface 11 of the first layer 10 and the one surface 21 of the second layer 20 opposed to the first layer 10 are joined by the adhesive force of the resin constituting the second layer 20.

  Both the layers 10 and 20 have the same plane size, and the one side 11 and 21 and the other side 12 and 22 are in a front-back relationship. In the present embodiment, the first layer 10 is also made of resin. Specifically, both layers 10 and 20 are made of a thermosetting resin such as an epoxy resin.

  Here, in the second layer 20, a filler having electrical insulation and thermal conductivity is further contained in the thermosetting resin, and the filler is dispersed in the thermosetting resin. . The filler is made of an inorganic material such as alumina or silica, and has a spherical shape, a flake shape, a fiber shape, or the like.

  In addition, a plurality of conductors 30 and other conductors 31 configured as interlayer wirings are arranged on the one surface 11 of the first layer 10 so as to be separated from each other at the interface between the one surfaces 11 and 21 of the both layers 10 and 20. Has been. Although a plurality of conductors 30 are shown in FIG. 1, they function as, for example, a wiring for a large current and require heat dissipation.

  Further, one other conductor 31 is shown in FIG. 1, but a plurality of other conductors 31 may be provided or not provided as necessary. The other conductor 31 functions as a wiring for relatively low current, for example, and does not require heat dissipation. These conductors 30 and other conductors are made of a conductive metal foil or the like, and are formed, for example, by bonding a Cu foil to one surface 11 of the first layer 10 and etching it to a desired wiring pattern.

  Furthermore, a heat radiating member 40 is provided on the plurality of conductors 30 that need to dissipate heat on the one surface 11 of the first layer 10. The heat radiating member 40 has a function of radiating heat generated in the conductor 30. The heat dissipating member 40 is mounted independently for each of the plurality of conductors 30 so that the heat dissipating members 40 on the conductors 30 are separated from each other between the plurality of conductors 30.

  The plurality of conductors 30, the heat dissipation member 40, and the other conductors 31 protrude from the one surface 11 of the first layer 10 and are embedded in the second layer. In the present embodiment, the heat dissipation member 40 is exposed on the other surface 22 of the second layer 20.

  Here, between the adjacent conductors 30 and 31, the conductors 30 and 31 and the heat dissipating members 40 on the conductor 30 are not in contact with each other. Therefore, between the conductors 30 and 31, the second layer 20 reaches the one surface 11 of the first layer 10, so that the space between the conductors 30 and 31 is filled with the second layer 20.

  Here, the planar size of the heat radiating member 40 may be the same as the planar size of the portion of the conductor 30 located immediately below the heat radiating member 40 as long as the heat radiating member 40 can be mounted directly above the conductor 30. It may be larger or slightly smaller.

  In this embodiment, in order to ensure heat dissipation as much as possible, as shown in FIG. 1, the heat radiating member 40 has a plane size that is slightly larger than the conductor 30 portion directly below the heat radiating member. For example, when the portion of the conductor 30 immediately below the heat radiating member is rectangular, the heat radiating member 40 can be a rectangular plate that is slightly larger than that (see FIG. 5 described later).

  The heat dissipation member 40 is made of a material that is harder than the second layer 20 and has a high thermal conductivity. In this embodiment, the heat radiating member 40 is the same as the second layer 20 in which the filler is dispersed and contained in a thermosetting resin such as an epoxy resin, but the heat radiating member 40 is the second one. It is assumed that the filler content is higher than that of the layer 20.

  Although it does not limit, for example, as the filler content, the heat dissipation member 40 is 80% by weight or more, and the second layer 20 is 50% by weight or less. Thus, by making the filler content different between the heat radiating member 40 and the second layer 20, the heat radiating member 40 is made of a material harder than the second layer 20 and having a higher thermal conductivity. ing.

  Further, the thermosetting resin that constitutes the second layer 20 and the thermosetting resin that constitutes the heat dissipation member 40 may be the same material or different materials. When the same material is used, both the thermosetting resins are made of, for example, epoxy resins having the same composition. When different materials are used, the two thermosetting resins may be epoxy resins having different compositions, for example, or one resin may be an epoxy resin and the other a polyimide resin. .

  For example, if the heat radiating member 40 is made of a polyimide resin having a filler content higher than that of the second layer 20, the heat radiating member 40 has higher insulation in addition to high heat radiating properties.

  Next, a method for manufacturing the multilayer wiring board S1 according to the present embodiment will be described with reference to FIGS. 4 and 5 show more specific arrangement patterns of the conductors 30 and 31 on the first surface 11 of the first layer 10, but they are only examples.

  First, as shown in FIG. 2, the first layer 10 and the second layer 20 are prepared (preparation process). Specifically, in this preparation step, the first layer 10 is prepared as a layer in which a thermosetting resin is formed and cured.

  On the other hand, the second layer 20 is prepared by forming the thermosetting resin containing the above-described filler into a layer shape, heating it, and semi-curing it into a B-stage state, for example. Thus, the second layer 20 is prepared as being softer than the first layer 10.

  Also, as shown in FIGS. 2 and 4, a plurality of conductors 30 and other conductors 31 are arranged apart from each other on one surface 11 of the first layer 10 (conductor arrangement step). Specifically, in the conductor placement step, a plurality of conductors 30 are formed on the first surface 11 of the first layer 10 so as to be spaced apart by pasting and etching the Cu foil.

  Next, a heat radiating member process is performed. In this heat radiating member process, as shown in FIGS. 2 and 5, the heat radiating member 40 is mounted on the conductor 30 independently for each of the plurality of conductors 30. The heat radiating members 40 on the 30 are separated from each other. Specifically, the heat radiating member 40 is applied directly on the conductor 30 independently for each conductor 30 by a printing method using a mask, a dispensing method, or the like.

  Here, a printing method is desirable for high definition of the conductor 30 pattern. And after this application | coating, each heat radiating member 40 is heated, for example, is semi-hardened to a B-stage state. In the heat radiating member process, the semi-cured sheet-like heat radiating member 40 may be mounted on each conductor 30.

  The semi-cured heat radiation member 40 is also harder than the semi-cured second layer 20 because the filler content is higher than the prepared semi-cured second layer 20. In addition, the thermal conductivity is large.

  next. As shown in FIGS. 2 to 3, a pressing process is performed. In this pressing step, the one surface 21 of the second layer 20 is opposed to the one surface 11 of the first layer 10 and both the layers 10 and 20 are pressed. This pressing can be performed by a normal pressing device used to form this type of laminated wiring board.

  By this pressing, the surfaces 11 and 21 of the two layers 10 and 20 are bonded together while the plurality of conductors 30 and the heat dissipation member 40 are embedded in the second layer 20. At this time, in the present embodiment, the pressing is performed until the heat radiating member 40 is exposed on the other surface 22 of the second layer 20.

  In this pressing step, the heat dissipating members 40 are separated from each other between the conductors 30 and the heat dissipating member 40 is harder than the second layer 20, so that the second layer 20 is also between the conductors 30. While reaching 40, it reaches the one surface 11 of the first layer 10, and the space between the conductors 30 is filled with the second layer 20.

  And after this press process, a hardening process is performed and the 2nd layer 20 and the thermal radiation member 40 of a semi-hardened state are made into a completion state of hardening. Thus, the multilayer wiring board according to the present embodiment is completed.

  Thus, according to the present embodiment, it is possible to reach the one surface 11 of the first layer 10 even between the conductors 30 by pressing and fill the spaces between the conductors 30. Therefore, according to the present embodiment, a configuration in which the first layer 10 and the second layer 20 are stacked without generating a gap between the plurality of conductors 30 that are interlayer wirings that require heat dissipation is realized. can do.

  In the present embodiment, the second layer 20 and the heat dissipation member 40 are preferably made of the same thermosetting resin material. In this case, the thermosetting resin material constituting the second layer 20 and the thermosetting resin constituting the heat radiation member 40 are made of the same material, and the heat radiation member 40 has a higher filler content. It shall be a thing.

  In this case, after the pressing step, the second layer 20 and the heat radiating member 40 are heated in the curing step to complete the curing. And since the 2nd layer 20 and the heat radiating member 40 consist of the same thermosetting resin material, the adhesion | attachment of the interface of these both 20 and 40 can be strengthened after a hardening process.

  Moreover, according to this embodiment, since the heat radiating member 40 is exposed in the other surface 22 of the 2nd layer 20, it is easy to perform thermal connection with the heat radiating member 40 and another member in the said other surface 22 side. . For example, in the case of forming a configuration in which another layer made of resin is further laminated on the other surface 22 side of the second layer 20, a heat conduction path through the heat dissipation member is also formed on the other layer side. Cheap.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. 6 with a focus on differences from the first embodiment. In the first embodiment, as shown in FIG. 1, the side surface of the heat dissipation member 40 is parallel to the thickness direction of the second layer 20 (that is, the stacking direction of both layers 10 and 20).

  On the other hand, in this embodiment, as shown in FIG. 6, the side surface 41 of the heat dissipation member 40 is inclined in the thickness direction of the second layer 20, so that the heat dissipation member 40 is The layer 20 has a tapered shape constricted from the one surface 21 side to the other surface 22 side. In this case, it is desirable in that the heat dissipation member 40 is easily embedded in the second layer 20 during the pressing step.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. 7 with a focus on differences from the first embodiment. In the present embodiment, as shown in FIG. 7, a heat dissipation layer 50 made of the same material as the heat dissipation member 40 is further laminated on the other surface 22 of the second layer 20 to further improve heat dissipation. is there.

  In this case, the heat dissipation layer 50 is thermally connected to the heat dissipation member 40 by contacting the heat dissipation member 40 exposed on the other surface 22 of the second layer 20. Such a heat dissipation layer 50 is performed up to the curing step by the manufacturing method of the first embodiment, and after the first layer 10 and the second layer 20 are laminated, the heat dissipation layer 50 is formed on the second layer 20. Bonded, cured and attached.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. 8 with a focus on differences from the first embodiment. The heat radiating member 40 is not limited to the one exposed at the other surface 22 of the second layer 20, and the entire heat radiating member 40 is within the second layer 20 as shown in FIG. 8. It may be buried in. This structure is formed by pressing so as to be in the state of FIG.

(Other embodiments)
In each of the above embodiments, the first layer 10 is made of a thermosetting resin, and the second layer 20 and the heat dissipation member 40 are made of a thermosetting resin containing a filler. However, these three members may be made of, for example, a photocurable resin. Further, the first layer 10 and the heat radiating member 40 may be made of, for example, ceramic or the like as long as the above-described characteristics are ensured.

  In the multilayer wiring board in each of the above embodiments, two layers of the first layer 10 and the second layer 20 are stacked. However, the stacked layers of the first and second layers 10 and 20 are stacked. As long as it has a configuration, the laminated wiring board may be a laminate of three or more layers.

  Although not shown as such a laminated wiring board, for example, another layer made of resin is laminated on the other surface 12 side of the first layer 10 or the other surface 22 side of the second layer 20 in FIG. It may be what was done.

  In this case, the other layer may be formed by forming the first layer 10 and the second layer 20 by the above manufacturing method, and further laminating and curing them in a B-stage or the like state. When there are a plurality of other layers, the other layers may be stacked and cured sequentially one by one, or all the other layers may be stacked and cured at once.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims. The above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible, and the above embodiments are not limited to the illustrated examples. Absent.

DESCRIPTION OF SYMBOLS 10 1st layer 11 One surface of 1st layer 20 2nd layer 30 Conductor 40 Heat radiation member

Claims (6)

Laminating at least two layers of a first layer (10) and a second layer (20) made of resin, and an interlayer between both the first layer and the second layer A method of manufacturing a laminated wiring board formed by forming a plurality of conductors (30) to be wiring,
A preparation step of preparing the first layer and the second layer;
A conductor placement step of placing the plurality of conductors (30) separately on one surface (11) of the first layer;
A heat radiating member (40) that is harder than the second layer and has a high thermal conductivity is mounted on the conductor independently for each of the plurality of conductors, so that the conductors between the plurality of conductors A heat radiating member step in which the heat radiating members are separated from each other,
A state in which the one surface (21) of the second layer is opposed to one surface of the first layer and both the layers are pressed to embed the plurality of conductors and the heat dissipation member in the second layer. And a pressing step of bonding the surfaces of the two layers together. As said 2nd layer and said heat radiating member, content of the filler which consists of the same thermosetting resin material and has the electrical insulation and heat conductivity contained in the said thermosetting resin material is included. It is different, and further, the heat radiating member uses a material having a higher content of the filler,
The method for manufacturing a multilayer wiring board according to claim 1, wherein after the pressing step, a curing step of heating and curing the second layer and the heat dissipation member is performed.   3. The multilayer wiring according to claim 1, wherein, in the pressing step, the pressing is performed until the heat radiating member is exposed on the other surface (22) opposite to the one surface of the second layer. A method for manufacturing a substrate. A first layer (10);
A second layer (20) made of a resin laminated on one surface (11) of the first layer;
A plurality of conductors (30) configured as interlayer wiring by being spaced apart on one surface of the first layer in a state of being embedded in the second layer;
A heat dissipating member (40) made of a material harder than the second layer and having a higher thermal conductivity provided on the plurality of conductors in a state of being embedded in the second layer,
The heat dissipating member is mounted independently for each of the plurality of conductors, and the heat dissipating members on the conductors are separated from each other between the plurality of conductors.
A laminated wiring board characterized in that the second layer reaches one surface of the first layer between the conductors to fill the space between the conductors.   The second layer and the heat radiating member are made of the same thermosetting resin material, and the content of the electrically insulating and thermally conductive filler contained in the thermosetting resin material is the same. The multilayer wiring board according to claim 4, wherein the laminated wiring board is different, and further, the heat radiating member has a higher content of the filler.   6. The multilayer wiring board according to claim 4, wherein the heat dissipating member is exposed on the other surface (22) opposite to the one surface of the second layer.

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