JP6910630B2 - Manufacturing method of wiring board laminate and wiring board laminate - Google Patents

Description

The present invention relates to a method for manufacturing a wiring board laminate in which a metal plate having a plurality of convex portions and a wiring board are laminated and integrated, and a wiring board laminate obtained by the method, which is used in an inverter device, a voltage conversion device, and the like. It is useful as a technique for manufacturing a substrate having good heat dissipation characteristics.

Conventional power semiconductor modules include a metal base plate for heat dissipation, a ceramic substrate laminated on the base plate, a power semiconductor chip (power chip such as an IGBT) mounted on the base plate, and a resin case for accommodating these. , It was equipped with electrode terminals arranged in a resin case on the side of the ceramics substrate.

Further, the semiconductor chip and the ceramic substrate or these and the electrode terminal are connected by a bonding wire, and the inside of the resin case is filled with a sealing material. As a result, the insulation between the semiconductor chip for electric power, the ceramic substrate, the metal base plate, and the electrode terminals is ensured. Further, in the power semiconductor module, a metal base plate is attached to a cooling member such as a heat sink to have a structure capable of dissipating heat.

Then, instead of connecting with a bonding wire such as aluminum, there is a technique of forming a circuit by connecting to a terminal on the upper surface of a semiconductor chip by using a wiring board having a plurality of columnar metal bodies having higher heat dissipation characteristics (). For example, see Patent Document 1).

However, since the heat from the semiconductor chip is mainly transferred from the ceramics substrate to the metal base plate, it is necessary to improve these heat dissipation structures in order to further improve the heat dissipation characteristics. At that time, if heat can be dissipated directly to the metal base plate without going through the ceramics substrate, the heat dissipation characteristics can be significantly improved.

However, the back surface side of the semiconductor element (semiconductor chip or semiconductor package) is connected to the circuit as an electrode to form a part of the circuit, and the back surface side electrodes of a plurality of semiconductor elements are connected to the same metal base plate. It is necessary to avoid this in terms of circuit configuration. This point has been a barrier when using a metal-based substrate that does not use a ceramic substrate.

On the other hand, for a substrate on which a light emitting element such as an LED is mounted and the heat is dissipated to a metal plate, there is a technique of forming a pattern of a metal plate for heat dissipation and making it a part of a circuit (for example, Patent Document). 2). That is, a substrate for mounting a light emitting element including two or more columnar metal bodies, two or more electrodes provided on the back surface side of the columnar metal body while conducting conduction, and an insulating layer that exposes the upper surface of the columnar metal body. Proposed.

Japanese Unexamined Patent Publication No. 2014-154679 Japanese Unexamined Patent Publication No. 2011-108688

However, in the structure of the substrate described in Patent Document 2, the strength and rigidity of the substrate are lowered in the non-patterned portion after the metal plate is patterned, so that it is difficult to use as a substrate for a semiconductor module. rice field. Further, since it is difficult to form a circuit with such a simple structure, it cannot be used as a substrate for a semiconductor module.

Therefore, an object of the present invention is a wiring board capable of preventing a short circuit through a metal plate while enabling heat dissipation to the metal plate, having sufficient strength in a non-patterned portion of the metal plate, and being able to cope with a complicated circuit. An object of the present invention is to provide a method for manufacturing a laminated body and a wiring board laminated body obtained by the method.

The above object of the present invention can be achieved by the present invention as follows.
That is, the method for manufacturing the wiring board laminate of the present invention is as follows.
A metal plate having a plurality of convex portions, an insulating layer forming material having a plurality of first openings in the portions corresponding to the convex portions and containing a thermosetting resin, and a plurality of second portions in the portions corresponding to the convex portions. A process of preparing a wiring board having an opening or a material for forming the wiring board, and
The metal plate, the insulating layer forming material, and the wiring board or the forming material thereof are laminated while aligning the convex portion, the first opening, and the second opening, and the convex portion is heated and pressed. A step of forming a laminate having a height equal to or higher than the surface of the wiring board or the material for forming the wiring board.
A step of removing at least the insulating layer forming material that covers the convex portion, and
It is characterized by including a step of forming a pattern of the metal plate of the laminated body.

According to the method for manufacturing a wiring board laminate of the present invention, when a laminate is formed by heating and pressurizing, a part of an insulating layer forming material such as a thermosetting resin flows out from an opening and is one of the upper surfaces of a convex portion or the like. Cover part or all. At that time, in the obtained laminate, the height of the convex portion is the same as or higher than the surface of the wiring board or the like, so that the insulating layer forming material covering the convex portion can be easily removed by a belt sander or the like. , A structure capable of dissipating heat to the metal plate via the convex portion can be obtained. Further, by forming the pattern of the metal plate, it is possible to prevent a short circuit through the metal plate. At that time, in addition to the insulating layer forming material, the wiring board or the forming material thereof is laminated and integrated, so that the strength in the non-patterned portion of the metal plate is sufficient, and the lamination of the wiring board or the forming material thereof is later patterned. By doing so, it becomes possible to handle complicated circuits.

As a result, a method for manufacturing a wiring board laminate that can prevent short circuits through the metal plate while enabling heat dissipation to the metal plate, has sufficient strength in the non-patterned portion of the metal plate, and can handle complicated circuits. Can be provided.

In the above, a mask material having a third opening in the same portion as the second opening of the wiring board and arranged or attached on the wiring board or its forming material is prepared, and the mask material is used. After forming the laminate, it is preferable to remove the mask material and then remove the insulating layer forming material that covers the convex portion.

When such a mask material is not used, the height of the convex portion in the laminated body is higher than the surface of the wiring board or the like, so that the surface around the second opening of the wiring board or the like is easily coated with the thermosetting resin or the like. And it becomes difficult to remove it. As in the above configuration, by using a mask material that has a third opening in the same portion as the second opening and is arranged or attached on the wiring board or its forming material, the laminated body is heated and pressed. At the time of formation, it becomes possible to prevent the surface around the second opening of the wiring board or the like from being coated with the thermosetting resin or the like.

Further, it is preferable to include a step of forming the second opening and the third opening at the same time with the mask material attached on the wiring board or the forming material thereof. As a result, it is not necessary to separately form and align the second opening and the third opening, and the productivity can be further improved.

Further, it is preferable that the insulating layer forming material contains reinforcing fibers. This makes it easier to control the thickness of the insulating layer and adjust the amount of the thermosetting resin or the like partially flowing out from the opening when the laminate is formed by heating and pressurizing.

Further, it is preferable that the wiring board is a multi-layer wiring board having two or more wiring layers. This makes it possible to manufacture a wiring board laminate that can be used for more complicated circuits.

Further, in the present invention, in the step of forming the pattern of the metal plate, by providing the back surface side convex portion on the back surface side of the convex portion, the wiring board laminate penetrates from the convex portion and the back surface side convex portion. It is preferable to form a penetrating metal body. Through such a process, columnar metal bodies can be collectively inserted into the wiring board with a simple operation, alignment accuracy is not strictly required, columnar metal bodies of different shapes can be handled, and columnar metal bodies are adhered. A wiring board having sufficiently high strength can be obtained.

That is, conventionally, as a technique for improving heat dissipation, a method of soldering a heat dissipation terminal of a heat generating component onto a coin-shaped copper (copper inlay) has been known, but a copper inlay is inserted into a through hole. Therefore, there is a problem that high accuracy is required for alignment and the insertion process becomes complicated. Further, since a press-fitting device for automation is used when inserting the copper inlay, it is necessary to make the copper inlay the same shape, and there is a problem that the degree of freedom in designing the copper inlay is reduced.

In the above, an insulating layer forming material having a plurality of first openings in a portion corresponding to the back surface side convex portion and containing a thermosetting resin, and a plurality of second openings in a portion corresponding to the back surface side convex portion. A step of preparing a wiring board or a material for forming the wiring board, the laminate, the insulating layer forming material, and the wiring board or the material for forming the wiring board, the back surface side convex portion, the first opening, and the second opening. To form a laminated body in which the height of the back surface side convex portion is the same as or higher than the front surface of the wiring board or the material for forming the wiring board by heating and pressurizing, and at least the back surface side convex portion. It is preferable to further include a step of removing the insulating layer forming material that covers the portion.

By such a process, the wiring boards are provided on both sides and the structure has a penetrating metal body penetrating them, and bending deformation and the like are less likely to occur, so that the step of removing the insulating layer forming material on both sides can be easily performed. Will be.

On the other hand, the wiring board laminate of the present invention has a metal plate having a plurality of convex portions on the front surface side and a pattern formed on the back surface side, and a wiring substrate having a plurality of second openings in a portion corresponding to the convex portions. And an insulating layer containing a cured product of the thermosetting resin, which is interposed between the metal plate and the wiring board, and the thermosetting resin continuous from the insulating layer is a convex portion of the metal plate. It is characterized in that at least the upper surface of the convex portion and the upper surface of the wiring board are exposed while filling the space between the second opening and the second opening.

According to the wiring substrate laminate of the present invention, since the metal plate having a plurality of convex portions is provided and at least the upper surface of the convex portions is exposed, a structure capable of dissipating heat to the metal plate via the convex portions can be obtained. Further, by forming the pattern of the metal plate, it is possible to prevent a short circuit through the metal plate. Further, since it has a wiring board, the strength of the non-patterned portion of the metal plate is sufficient, and it becomes possible to cope with a complicated circuit. As a result, a wiring board laminate capable of preventing a short circuit through the metal plate while enabling heat dissipation to the metal plate, having sufficient strength in the non-patterned portion of the metal plate, and being able to cope with a complicated circuit is provided. be able to.

In the above, it is preferable that the wiring board is a multilayer wiring board having two or more wiring layers. This makes it possible to manufacture a wiring board laminate that can be used for more complicated circuits.

Further, it is preferable that the wiring board is a multi-layer wiring board having through holes for electrically connecting two or more wiring layers. As a result, it is possible to manufacture a wiring board laminate that can be used for more complicated circuits.

The wiring board laminate of the present invention can prevent a short circuit through the metal plate while enabling heat dissipation to the metal plate, has sufficient strength in the non-patterned portion of the metal plate, and can cope with a complicated circuit. , It is useful as a mounting substrate for power semiconductor elements.

Further, another wiring board laminated body of the present invention is laminated on a plurality of penetrating metal bodies, a wiring board having a plurality of second openings in a portion corresponding to the penetrating metal body, and the wiring board, and is thermosetting. A thermosetting resin containing an insulating layer containing a cured product of the resin and continuous from the insulating layer fills the space between the penetrating metal body and the second opening, and at least the upper surface of the penetrating metal body. The upper surface of the wiring board is exposed.

Alternatively, another wiring board laminate of the present invention is between the plurality of through metal bodies, the upper and lower wiring boards having a plurality of second openings in the portions corresponding to the through metal bodies, and the upper and lower wiring boards. At least the said The upper surface of the penetrating metal body and the upper surface of the wiring board are exposed.

By the manufacturing method of the present invention, these wiring board laminated bodies can be inserted into the wiring board at once by a simple operation, alignment accuracy is not strictly required, and columnar metal bodies having different shapes can be used. It is possible to obtain a wiring board that can be used and has a sufficiently high adhesive strength of the columnar metal body.

Sectional drawing which shows an example of the wiring board laminated body of this invention Top view of the wiring board laminate shown in FIG. Sectional drawing which shows an example of the manufacturing method of the wiring board laminated body of this invention Sectional drawing which shows an example of the manufacturing method of the wiring board laminated body of this invention Sectional drawing which shows another example of the wiring board laminated body of this invention Bottom view of the wiring board laminate shown in FIG. Sectional drawing which shows another example of the wiring board laminated body of this invention Sectional drawing which shows another example of the wiring board laminated body of this invention Sectional drawing which shows another example of the wiring board laminated body of this invention Cross-sectional view showing another example of the manufacturing method of the wiring board laminated body of this invention. Sectional drawing which shows another example of the wiring board laminated body of this invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the usage state of the wiring board laminate of the present invention. The wiring board laminate of the present invention is useful as a mounting substrate for semiconductor elements, and is particularly useful as a mounting substrate for power semiconductor elements. Is. Here, the semiconductor element includes a semiconductor bare chip, a chip component, and a semiconductor package, and the power semiconductor element includes semiconductor elements such as various transistors and various diodes used in an inverter device, a voltage conversion device, and the like.

The packages of these power semiconductor devices generally include a metal heat sink in addition to the leads. The heat sink has an equipotential electrode with the heat sink depending on the package form, for example, the diode has the same potential as the cathode. In the illustrated example, a SiC transistor (FET) in which the heat sink (electrode 32) of the semiconductor element 30 is equipotential with the drain electrode is shown. In this figure, one semiconductor element 30 is shown, but another semiconductor element (Schottky barrier diode or the like) is mounted on other parts (not shown), and the heat sink and the semiconductor element 30 are mounted. The circuit is formed so that the potential is different from that of the heat sink.

Examples of the semiconductor element 30 include bipolar power transistors, MOSFETs, IGBTs, and FWDs (freewheeling diodes). Further, in addition to the conventional semiconductor element using Si, a semiconductor element using SiC (silicon carbide) or GaN (gallium nitride) can be used.

In the illustrated example, the heat sink (electrode 32) of the semiconductor element 30 and the convex portion 14 are connected by a solder 35, and the three leads (electrodes 31) and the wiring pattern 20 are connected by a solder 35. There is. If any of the three leads has the same potential as the heat sink (electrode 32), the electrical connection to the lead is omitted and the heat sink (electrode 32) is electrically connected. be able to.

As shown in FIG. 1, the wiring board laminate of the present invention has a metal plate 10 having a plurality of convex portions 14 on the front surface side (some of which are not shown) and a pattern formed on the back surface side, and the convex portions 14. Includes a wiring board WB having a plurality of second openings 19a and 20a in a portion corresponding to the above, and an insulating layer 16 interposed between the metal plate 10 and the wiring board WB and containing a cured product of a thermosetting resin. I'm out. Further, in the wiring board laminate of the present invention, at least the convex portion 14 is filled with the thermosetting resin continuous from the insulating layer 16 between the convex portion 14 of the metal plate 10 and the second openings 19a and 20a. The upper surface of the wiring board is exposed from the insulating layer 16 and the upper surface of the wiring board is exposed. In this embodiment, an example is shown in which the wiring board WB is a single-sided wiring board composed of a single-layer wiring pattern 20 and a rigid board 19. Here, the "rigid board" refers to an insulating board that can be used as a rigid wiring board.

As shown in FIGS. 1 and 2, the wiring pattern 20 is formed in a circuit together with the semiconductor element 30, and is electrically connected to the lead (electrode 31) of the semiconductor element 30 via the solder 35. Further, the patterned metal plate 10 is electrically connected to the heat radiating plate (electrode 32) of the semiconductor element 30 via the convex portion 14 and the solder 35. Another semiconductor element (not shown) is also connected to the wiring pattern 20 and formed into a circuit, and is electrically connected to the metal plate 10 which is patterned via the convex portion 14 and the solder 35.

In the present invention, as shown in FIG. 1, the metal substrate 10 is patterned, and the conduction region 10a conducting with the heat sink (electrode 32) of the semiconductor element 30 and the heat radiation of another semiconductor element (not shown) are dissipated. The conduction region that conducts with the plate is insulated. In the present embodiment, the insulating structure is formed by having a conductive region 10a that conducts with the electrode 32 of the semiconductor element 30 and a non-conducting region 10b that is insulated from the conductive region 10a by removing at least the periphery of the conductive region 10a. An example of the formation is shown.

A groove 10c leading to the insulating layer 16 is provided between the conductive region 10a and the non-conducting region 10b, and the non-conducting region 10b is insulated from the conductive region 10a.

Since the conductive region 10a is laminated and integrated with the insulating layer 16, it does not fall off even if the groove portion 10c is formed. At that time, the presence of the rigid substrate 19 of the wiring board WB reinforces the wiring board laminate. Therefore, the rigid substrate 19 preferably has higher rigidity and strength than the insulating layer 16.

The groove portion 10c can be formed by a cutting device such as a router or a die in addition to etching, but the groove portion 10c is preferably removed by etching. The width of the groove portion 10c is preferably 0.05 to 2 mm.

In the present embodiment, as shown by the virtual line in FIG. 1, it is preferable that the metal substrate 10 is provided with the heat sink 40, and at least the heat conductive material 41 is interposed in the conduction region 10a. As a result, the heat of the semiconductor element 30 can be efficiently transferred to the heat sink 40 via the conduction region 10a, and the heat dissipation effect can be further enhanced.

As the heat-conducting material 41, an insulating material is used, and a heat-conducting grease such as silicone grease, or a heat-conducting sheet in which a resin having adhesiveness or adhesiveness is filled with a heat-transmitting substance such as ceramics is used. It is possible. The heat conductive material 41 may be provided at least in the conductive region 10a, and may be provided in the non-conducting region 10b or the entire substrate including these.

As the heat sink 40, various heat sinks can be used depending on the required heat dissipation characteristics, and for example, a fin type, a rib type, a post type, or the like may be used. It may also be combined with a fan or a heat pipe.

Next, an example of the method for manufacturing the wiring board laminate of the present invention will be described while touching on the materials and the like used.

(1) First, as shown in FIG. 3 (e), a metal plate 10 having a plurality of convex portions 14 on the surface side and a plurality of first openings 16a in a portion corresponding to the convex portions 14 and thermosetting. An insulating layer forming material 16'containing a sex resin and a wiring board WB having a plurality of second openings 19a and 20a in a portion corresponding to the convex portion 14 or a forming material WB thereof are prepared.

The metal plate 10 having the plurality of convex portions 14 is formed, for example, as follows. As shown in FIGS. 3A to 3C, the surface metal layer 4 laminated on the metal substrate 10 is selectively etched to form a convex portion 14 at a position facing the electrode 32 of the semiconductor element 30. .. The surface metal layer 4 is laminated on the metal substrate 10 via another protective metal layer 2 that exhibits resistance during etching. The protective metal layer 2 can be omitted, and in that case, the convex portion 14 can be formed on the metal substrate 10 by controlling the etching amount.

As shown in FIG. 3A, a laminated plate SP in which the metal substrate 10, the protective metal layer 2 and the surface metal layer 4 for forming the convex portion 14 are laminated is prepared. The laminated board SP may be manufactured by any method, and for example, one manufactured by using electrolytic plating, electroless plating, sputtering, vapor deposition, or the like, or a clad material can be used. Regarding the thickness of each layer of the laminated plate SP, for example, the thickness of the metal substrate 10 is 100 to 2000 μm, the thickness of the protective metal layer 2 is 1 to 20 μm, and the thickness of the surface metal layer 4 is 10 to 500 μm.

The metal substrate 10 may be either a single layer or a laminated body, and the metal constituting the metal substrate 10 may be any metal, for example, copper, copper alloy, aluminum, stainless steel, nickel, iron, other alloys, and the like can be used. Of these, copper and aluminum are preferable from the viewpoint of thermal conductivity and electrical conductivity. Since the structure provided with the metal substrate 10 having good heat dissipation as described above can prevent the temperature rise of the semiconductor element 30, a larger drive current can be passed and the efficiency can be improved.

As the metal constituting the surface metal layer 4, copper, a copper alloy, nickel, tin or the like can be usually used, and copper is particularly preferable from the viewpoint of thermal conductivity and electrical conductivity.

As the metal constituting the protective metal layer 2, a metal different from the metal substrate 10 and the surface metal layer 4 is used, and another metal exhibiting resistance during etching of these metals can be used. Specifically, when these metals are copper, other metals constituting the protective metal layer 2 include gold, silver, zinc, palladium, ruthenium, nickel, rhodium, lead-tin solder alloy, or nickel. -Gold alloy etc. are used. However, the present invention is not limited to the combination of these metals, and any combination with another metal that exhibits resistance during etching of the metal can be used. When the protective metal layer 2 is not formed, another metal, the surface metal layer 4, can be directly formed on the metal substrate 10.

Next, as shown in FIG. 3B, the surface metal layer 4 is selectively etched using the etching resist M. As a result, the convex portion 14 is formed at the mounting position of the semiconductor element 30. The size of the convex portion 14 can be made smaller than the size of the mounted semiconductor element 30, for example, the diameter of the upper surface thereof is 1 to 10 mm. The shape of the upper surface of the convex portion 14 may be either a quadrangle or a circle.

As the etching resist M, a photosensitive resin, a dry film resist (photoresist), or the like can be used. When the metal substrate 10 is etched at the same time as the surface metal layer 4, it is preferable to provide a mask material on the lower surface of the metal substrate 10 to prevent this (not shown).

Examples of the etching method include an etching method using various etching solutions according to the type of each metal constituting the protective metal layer 2 and the surface metal layer 4. For example, when the surface metal layer 4 is copper and the protective metal layer 2 is the above-mentioned metal (including a metal-based resist), a commercially available alkaline etching solution, ammonium persulfate, hydrogen peroxide / sulfuric acid, or the like can be used. After etching, the etching resist M is removed.

Next, as shown in FIGS. 3C to 3D, the exposed protective metal layer 2 is removed, but the insulating layer 16 can be formed without removing the protective metal layer 2. The protective metal layer 2 can be removed by etching. Specifically, when the surface metal layer 4 is copper and the protective metal layer 2 is the above-mentioned metal, an acid-based etching solution such as nitric acid-based, sulfuric acid-based, or cyan-based, which is commercially available for solder peeling. Etc. are preferably used.

When the protective metal layer 2 exposed in advance is removed, the surface of the metal substrate 10 is exposed from the removed portion, but in order to improve the adhesion between the protective metal layer 2 and the insulating layer 16, surface treatment such as blackening treatment and roughening treatment is performed. Is preferable.

As shown in FIG. 3E, the insulating layer forming material 16'has a plurality of first openings 16a in the portion corresponding to the convex portion 14. The first opening 16a can be formed by a drill or a punch. The size of the first opening 16a is preferably slightly larger than the upper surface of the convex portion 14, but can be smaller than the upper surface of the convex portion 14. When the first opening 16a is made smaller than the upper surface of the convex portion 14, when the laminated body LB is formed by heating and pressurizing, that portion covers the upper surface of the convex portion 14, which is removed in a later step. It is possible.

The shape of the upper surface of the convex portion 14 and the shape of the first opening 16a and the like do not necessarily have to match, and both may have the same shape or different shapes (the same applies to other openings).

The insulating layer forming material 16'may contain a thermosetting resin, and is any material as long as it is deformed at the time of lamination and solidified by heating or the like and has the heat resistance required for the wiring board. It may be. Specific examples thereof include various reaction-curable resins such as polyimide resin, phenol resin and epoxy resin, and composites (prepregs) of the resin with glass fiber, ceramic fiber, aramid fiber and the like.

Further, the insulating layer forming material 16'is preferably made of a material having high thermal conductivity, and examples thereof include a resin containing a thermally conductive filler.

The insulating layer forming material 16'is preferably composed of a thermally conductive filler which is a metal oxide and / or a metal nitride and a resin (insulating adhesive). The metal oxide and the metal nitride are preferably those having excellent thermal conductivity and electrical insulation. Aluminum oxide, silicon oxide, beryllium oxide, and magnesium oxide are selected as the metal oxide, and boron nitride, silicon nitride, and aluminum nitride are selected as the metal nitride, and these can be used alone or in combination of two or more. .. In particular, among the metal oxides, aluminum oxide is said to be metal nitrided because an insulating adhesive layer having good electrical insulation and thermal conductivity can be easily obtained and can be obtained at low cost. Among the substances, boron nitride is preferable because it has excellent electrical insulation and thermal conductivity, and has a small dielectric constant.

Although the resin constituting the insulating layer forming material 16'contains metal oxides and / or metal nitrides, it has a bonding force with the metal substrate 10 (protective metal layer 12 if present) under a cured state. A material that is excellent in quality and does not impair the withstand voltage characteristics and the like is selected. As such resins, epoxy resins, phenol resins, polyimide resins, and various engineering plastics can be used alone or in combination of two or more. Of these, epoxy resins have excellent bonding strength between metals. preferable. In particular, among the epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, and hydrogenated epoxy resin, which have high fluidity and excellent mixability with the above-mentioned metal oxide and metal nitride. A bisphenol F type epoxy resin, a triblock polymer having a bisphenol A type epoxy resin structure at both ends, and a triblock polymer having a bisphenol F type epoxy resin structure at both ends are more preferable resins.

As shown in FIG. 3E, the wiring board WB or the material for forming the wiring board WB'has a plurality of second openings 19a and 20a in the portion corresponding to the convex portion 14 of the metal plate 10. In this embodiment, an example is shown in which the copper-clad rigid substrate before pattern formation is used as the forming material WB'of the wiring substrate WB. This copper-clad rigid substrate has a metal layer 20'and a cured insulating layer 19'adhered to the metal layer 20'with reinforcing fibers. As the material WB'for forming the wired substrate WB, a copper-clad laminate can also be used.

The second openings 19a and 20a can be formed by a drill or a punch. The size of the second openings 19a and 20a is preferably slightly larger than the upper surface of the convex portion 14, but can also be smaller than the upper surface of the convex portion 14. When the second openings 19a and 20a are made smaller than the upper surface of the convex portion 14, when the laminated body LB is formed by heating and pressurizing, that portion covers the upper surface of the convex portion 14, which will be covered in a later step. It can be removed.

The copper-clad laminate usually has a semi-cured insulating layer 19'adhered to the metal layer 20', but in the present invention, the insulating layer forming material 16'is used with the wiring board WB or its forming material WB'. Since adhesion is possible, it is possible to use a pre-cured insulating layer. Further, the surface of the insulating layer 19'may have a patterned metal layer.

As the material of the insulating layer 19', the same material as the insulating layer forming material 16' as described above can be used. Further, as the cured insulating layer, the same one as the cured product of the insulating layer forming material 16'as described above can be used.

Further, the metal layer 20'may be any metal, and for example, copper, copper alloy, aluminum, stainless steel, nickel, iron, other alloys and the like can be used. Of these, copper and aluminum are preferable from the viewpoint of thermal conductivity and electrical conductivity.

In this embodiment, as shown in FIG. 3E, the third opening 21a is provided in the same portion as the second openings 19a and 20a, and is attached on the forming material WB'of the wiring board WB. An example is shown in which a mask material 21 is prepared and the mask material 21 is used to form a laminated body LB.

The mask material 21 may be attached on the wiring board WB, or may be simply arranged on the wiring board WB or the forming material WB'. Further, as the mask material 21, it is also possible to use a mask material 21 that does not have the third opening 21a.

In the present invention, it is preferable to form the second openings 19a and 20a and the third opening 21a at the same time with the mask material 21 attached on the wiring board WB or its forming material WB', but these are separately formed. It is also possible to form in.

As the mask material 21, a resin film is preferable, and polyester such as polyethylene terephthalate, polyolefin such as polyethylene and polypropylene, and polyamide can be used. However, from the viewpoint of heat resistance, polyester such as polyethylene terephthalate is preferable.

Further, when the mask material 21 is attached, it is preferable to provide the adhesive layer on the mask material 21. As the pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, an acrylic-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or the like can be used. Instead of providing the pressure-sensitive adhesive layer on the mask material 21, it is also possible to separately apply a pressure-sensitive adhesive layer to form the mask material 21.

Further, as the mask material 21, a plate-shaped member can also be used. In that case, it is preferable to arrange without pasting. As such a mask material 21, a resin plate, a metal plate, a double-sided copper-clad laminate, a single-sided copper-clad laminate, or the like can be used.

(2) Next, as shown in FIGS. 3 (e) to 3 (f), the metal plate 10, the insulating layer forming material 19', and the wiring board WB or its forming material WB'are attached to the convex portion 14. The first opening 16a and the second openings 19a and 20a are laminated while being aligned with each other, and the height of the convex portion 14 is the same as the surface of the wiring board WB or the forming material WB'by heating and pressurizing. Form a taller laminate. In this embodiment, an example of forming a laminated body LB using the mask material 21 is shown.

As a result, as shown in FIG. 3 (f), the upper surface of the convex portion 14 is covered with the insulating layer forming material 16'(mainly a thermosetting resin) to have the convex portion A. Further, a part of the insulating layer forming material 16'may cover the periphery of the third opening 21a, but due to the presence of the mask material 21, the insulating layer forming material 16 is formed on the surface of the wiring board WB or the forming material WB'. 'Can be effectively prevented from adhering. That is, even if the insulating layer forming material 16'covers the periphery of the third opening 21a of the mask material 21, the insulating layer forming material 16'can be removed only by removing the mask material 21.

For heating and pressurizing, a method of heat-pressing by the press surface can be adopted, and at least a concave deformation is formed between the press surface and the laminated body so that the convex portion A can be easily formed at the position corresponding to the convex portion 14. It is preferable to arrange an acceptable sheet material. When the sheet material is not arranged, the height of the convex portion A is the same as the upper surface of the mask material 21. Further, a press surface having a concave portion at a position corresponding to the convex portion 14 may be used.

As a method of heating and pressing, a heating and pressurizing device (heat laminator, heating press) or the like may be used, and at that time, the atmosphere may be evacuated (vacuum laminator or the like) in order to avoid mixing of air. Conditions such as heating temperature and pressure may be appropriately set according to the material and thickness of the insulating layer forming material and the metal layer forming material, but the pressure is preferably 0.5 to 30 MPa.

The sheet material may be any material that allows concave deformation during heat pressing, such as cushion paper, rubber sheets, elastomer sheets, non-woven fabrics, woven fabrics, porous sheets, foam sheets, metal foils, and composites thereof. Can be mentioned. In particular, elastically deformable materials such as cushion paper, rubber sheets, elastomer sheets, foam sheets, and composites thereof are preferable.

(3) Next, as shown in FIG. 3 (g), at least the insulating layer forming material 16'that covers the convex portion 14 is removed. That is, the convex portion A above the convex portion 14 of the metal plate 10 is removed to expose the upper surface of the convex portion 14. When removing the convex portion A, it is preferable to remove the convex portion A so that the height of the upper surface of the metal layer 20'and the height of the convex portion 14 coincide with each other to flatten the metal layer 20'. However, in order to easily remove the insulating layer forming material 16', it is ideal that the height of the convex portion 14 is higher than that of the upper surface of the metal layer 20'.

In the present embodiment, the mask material 21 is removed prior to the removal of the convex portion A. However, the mask material 21 can be removed at the same time as the insulating layer forming material 16'is removed.

As a method for removing the convex portion A, a method by grinding or polishing is preferable, a method using a grinding device having a hard rotary blade in which a plurality of hard blades made of diamond or the like are arranged in the radial direction of the rotating plate, a sander, and a belt sander. , A method using a grinder, a surface grinding machine, a hard abrasive grain molded product, or the like. When the grinding device is used, the upper surface can be flattened by moving the rigid rotary blade along the upper surface of the fixedly supported wiring board while rotating the hard rotary blade. Further, as a polishing method, a method of lightly polishing by belt sander, buff polishing or the like can be mentioned. When the convex portion A is formed on the laminated body LB as in the present invention, it becomes easy to grind only that portion, and the entire flattening can be performed more reliably.

When the forming material WB'of the wiring board WB is laminated and integrated as in the present embodiment, the metal layer 20'is formed into a pattern as needed. Prior to this, the exposed convex portion 14 and the metal layer 20'can be metal-plated to form a metal-plated layer. As the metal type of metal plating, for example, copper, silver, Ni and the like are preferable. Examples of the method for forming the pattern of the metal plating layer include a panel plating method for forming a pattern using an etching resist, a pattern plating method for forming a pattern using a resist for pattern plating, and the like.

The pattern formation of the metal layer 20'can be performed as follows. For example, the wiring pattern 20 is formed by etching the metal plating layer and the metal layer 20'with a predetermined pattern using an etching resist. At that time, the metal substrate 10 can also be etched at the same time to form the groove portion 10c.

The etching resist may be appropriately selected depending on the type of etching resist, such as chemical removal and peeling removal. For example, in the case of photosensitive ink formed by screen printing, it is removed with a chemical such as alkali.

(4) Next, as shown in FIGS. 4A to 4B, the metal plate 10 of the laminated body LB is patterned. For example, by etching the metal plate 10 with a predetermined pattern using an etching resist M, the groove portion 10c can be formed to form a predetermined pattern.

Etching using the etching resist M can be performed in the same manner as the pattern formation of the metal layer 20'. In addition to etching, it is also possible to form a pattern using a cutting device such as a router or a die.

(Separate embodiment)
(1) In the above-described embodiment, an example of a wiring board laminate when the semiconductor element is a package is shown, but it can also be used when the semiconductor element is a chip-shaped semiconductor element such as a bare chip or a chip component as described below. ..

As shown in FIGS. 5 to 6, the wiring board laminate of the present invention is for mounting a chip-shaped semiconductor element 30 having at least one electrode 32 on the bottom surface and at least one electrode 31 on the upper surface. It is also possible to use it. In the illustrated example, the semiconductor element 30 has one electrode 32 on the bottom surface and two electrodes 31 on the upper surface.

The wiring pattern 20 is formed in a circuit together with the semiconductor element 30, and is electrically connected to the electrode 31 of the semiconductor element 30 via a wire 33. Further, the patterned metal plate 10 is electrically connected to the electrode 32 of the semiconductor element 30 via the convex portion 14. The electrode 32 and the convex portion 14 are connected by a solder 35 or the like.

In the present invention, as shown in FIG. 6, the metal substrate 10 is patterned, and the conduction region 10a conducting with the electrode 32 of the semiconductor element 30 and at least the periphery of the conduction region 10a are removed from the conduction region 10a. It has an insulated non-conducting region 10b. A groove 10c leading to the insulating layer 16 is provided between the conductive region 10a and the non-conducting region 10b, and the non-conducting region 10b is insulated from the conductive region 10a.

In this embodiment, the electrode 31 on the upper surface of the semiconductor element 30 and the convex portion 14 are electrically connected, but the electrode on the lower surface of the semiconductor element 30 and the wiring pattern 24 of the lower wiring substrate 20 are electrically connected. You may. For example, in the case of a semiconductor element 30 such as an IGBT, the collector on the lower surface is solder-bonded to the wiring pattern 24 of the lower wiring board 20 with solder 25 or the like, and the gate and the emitter on the upper surface serve as two electrodes 31 of the upper wiring board 10. Solder bonding is performed between the convex portion 14 and the solder 32 or the like. Further, examples of the electrical connection include solder bonding with solder 32, brazing, and bonding with gold bumps.

Further, in the case of FWD, the cathode electrode on the lower surface is solder-bonded to the wiring pattern 24 of the lower wiring board 20 with solder 25 or the like, and the anode electrode on the upper surface is soldered with the convex portion 14 of the upper wiring board 10 and the solder 32 or the like as the electrode 31. Be joined.

(2) In the above-described embodiment, an example in which a copper-clad laminate or the like is used as a material for forming the wiring board has been shown, but it is also possible to use the copper foil and the insulating layer separately. Further, instead of the material for forming the wiring board, it is also possible to use a wiring board in which all or part of the pattern is formed.

At that time, as shown in FIG. 7, it is also possible to use the double-sided wiring board as the wiring board WB. When a double-sided wiring board is used, it is preferable to have an interlayer connection structure such as a plated through hole, a metal bump, a filled via, and a plated via. Further, only the lower surface may be patterned in advance, and the upper surface may be patterned after laminating. Further, it is also possible to use a wiring board having three layers or four or more layers.

(3) In the above-described embodiment, an example of forming a circuit with a wiring pattern via a convex portion of a metal plate has been shown. However, as shown in FIG. 8, a plated through hole for interlayer connection between the metal plate 10 and the wiring pattern 20. It is also possible to provide 22.

Such a plated through hole 22 can be formed by providing a through hole with a drill or the like and then performing metal plating. At that time, by masking the upper and lower surfaces, it is possible to prevent the portions other than the through holes from being plated. It is also possible to provide the plating through holes 22 and the plating layers on the upper and lower surfaces before forming the pattern of the metal plate 10 without masking, and to form the pattern of the metal plate 10 later.

(4) In the above-described embodiment, an example of forming a laminated body using a mask material has been shown, but in the present invention, a wiring board or a material for forming the laminated body is laminated without using a mask material to form a laminated body. It is also possible to form. In that case, the insulating layer forming material is coated around the second opening of the wiring board or the forming material thereof, which can be removed in a later step.

(5) In the above-described embodiment, an example in which the plating layer is not provided on the upper surface of the convex portion 14 of the metal plate 10 is shown, but in the present invention, as shown in FIG. 9, the upper surface of the convex portion 14 of the metal plate 10 is provided. The plating layer 23 may be provided on the surface. Further, a plating layer 23 may be provided on the upper surface of the metal layer 20', and the wiring pattern 20 may be formed by etching or the like on these plating layers 23. By forming the wiring pattern 20 that conducts with the convex portion 14 of the metal plate 10, even if the conduction region 10a of the metal plate 10 is independent of the surroundings, it is easy to form a circuit when the semiconductor element 30 is mounted. become.

(6) In the above-described embodiment, only the wiring board laminate of the portion on which the semiconductor element 30 is mounted is shown, but for the other portion of the wiring board laminate, a wiring pattern corresponding to the circuit is provided. In addition, electronic components corresponding to the circuit are mounted.

(7) In the above-described embodiment, in the step of forming the pattern of the metal plate, an example is shown in which a large number of portions that do not conduct with the convex portion are present on the back surface side of the metal plate. As shown in d), in the present invention, in the step of forming the pattern of the metal plate 10, by providing the back surface side convex portion 15 on the back surface side of the convex portion 14, the convex portion 14 and the back surface side convex portion 15 are provided. Therefore, a penetrating metal body TM that penetrates the wiring substrate laminate may be formed.

In that case, as shown in FIG. 10 (c), the insulating layer forming material 16'having a plurality of first openings 16a in the portion corresponding to the back surface side convex portion 15 and containing the thermosetting resin, and the back surface side. A wiring board WB or a material for forming the wiring board WB'having a plurality of second openings 19a and 20a in a portion corresponding to the convex portion 15 is prepared.

Next, as shown in FIG. 10D, the laminated body LB, the insulating layer forming material 16', and the wiring board WB or the forming material WB'are attached to the back surface side convex portion 15, the first opening 16a, and the second opening 19a. , 20a are laminated while being aligned with each other, and a step of forming a laminated body in which the height of the back surface side convex portion 15 is the same as or higher than the surface of the wiring board WB or its forming material WB'by heating and pressurizing. , At least the step of removing the insulating layer forming material 16'that covers the back surface side convex portion 15 can be further carried out.

By such a step, as shown in FIG. 10D, the plurality of penetrating metal bodies TM, the upper and lower wiring boards WB having a plurality of second openings 19a and 20a in the portions corresponding to the penetrating metal bodies TM, and the upper and lower wiring boards WB. The thermosetting resin, which is interposed between the upper and lower wiring boards WB and includes an insulating layer 16 containing a cured product of the thermosetting resin and is continuous from the insulating layer 16, forms a penetrating metal body TM and the second opening. It is possible to obtain a wiring board laminate in which at least the upper surface of the penetrating metal body TM and the upper surface of the wiring board are exposed while filling the space between 19a and 20a.

The wiring board WB on the back surface side or its forming material WB'can have the same material and structure as the wiring board WB on the front surface side or its forming material WB', and these are as described above. Further, the same configuration as described above can be adopted for the formation of the metal plating layer and the pattern formation on the back surface side.

(8) In the embodiment of (7) above, the wiring board WB is also provided on the back surface side, but only the insulating layer may be provided on the back surface side. As a result, the plurality of penetrating metal bodies TM, the wiring board WB having a plurality of second openings 19a and 20a in the portions corresponding to the penetrating metal body TM, and the wiring board WB are laminated and the thermosetting resin is cured. An insulating layer 16 containing an object, and a thermosetting resin continuous from the insulating layer 16 fills the space between the penetrating metal body TM and the second openings 19a and 20a, and at least the penetrating metal body TM. It is possible to obtain a wiring board laminate in which the upper surface of the wiring board and the upper surface of the wiring board WB are exposed.

(9) In the above-described embodiment, the terminal structure for connecting the wiring in the wiring board laminate is not mentioned, but as shown in FIG. 11, the patterned plating layer 23 (wiring pattern) A convex portion 14 electrically connected to the convex portion 14 may be provided, and the wiring 36 may be connected to the pattern portion (terminal) of the metal plate 10 existing on the back surface side of the convex portion 14 by a solder 35. By providing the terminals for connecting the wiring on the back surface side in this way, the degree of freedom in design for component mounting can be increased.

10 Metal plate 14 Convex part 15 Convex part on the back side 16 Insulation layer 16'Insulation layer forming material 16a First opening 19 Rigid substrate 19' Semi-hardened insulation layer 19a Second opening 20 Wiring pattern 20'Metal layer 20a Second opening 21 Mask material 21a Third opening 30 Semiconductor element 31 Electrode (lead)
32 Electrode (heat sink)
35 Solder A Convex part B Flat surface WB Wiring board WB'Wire board forming material LB Laminated body TM Penetrating metal body

Claims (8)

A metal plate having a plurality of convex portions, an insulating layer forming material having a plurality of first openings in the portions corresponding to the convex portions and containing a thermosetting resin, and a plurality of second portions in the portions corresponding to the convex portions. A wiring board having an opening or a material for forming the wiring board and a mask material having a third opening simultaneously formed in the same portion as the second opening and pasted on the wiring board or the material for forming the wiring board are prepared. Process and
The metal plate, the insulating layer forming material, the wiring board, the forming material thereof, and the mask material are laminated in a state where the convex portion, the first opening, the second opening, and the third opening are aligned. A step of forming a laminate in which the height of the convex portion is equal to or higher than the surface of the wiring board or the material for forming the wiring board by heating and pressurizing.
After removing the mask material, at least the step of removing the insulating layer forming material covering the convex portion, and
A method for manufacturing a wiring board laminate, which comprises a step of forming a pattern of the metal plate of the laminate. The method for manufacturing a wiring board laminate according to claim 1, further comprising a step of simultaneously forming the second opening and the third opening in a state where the mask material is attached on the wiring board or a material for forming the wiring board. .. The method for manufacturing a wiring board laminate according to claim 1 or 2, wherein the insulating layer forming material contains reinforcing fibers. The method for manufacturing a wiring board laminate according to any one of claims 1 to 3, wherein the wiring board is a multilayer wiring board having two or more wiring layers. In the step of forming the pattern of the metal plate, by providing the back surface side convex portion on the back surface side of the convex portion, a penetrating metal body penetrating the wiring substrate laminate is formed from the convex portion and the back surface side convex portion. The method for manufacturing a laminated wiring substrate according to any one of claims 1 to 4. An insulating layer forming material having a plurality of first openings in the portion corresponding to the back surface side convex portion and containing a thermosetting resin, and a wiring board having a plurality of second openings in the portion corresponding to the back surface side convex portion. The forming material, the process of preparing,
The laminated body, the insulating layer forming material, and the wiring board or the forming material thereof are laminated while aligning the back surface side convex portion, the first opening, and the second opening, and the back surface is heated and pressed. A step of forming a laminate in which the height of the lateral convex portion is the same as or higher than the surface of the wiring board or the material for forming the wiring board.
A step of removing at least the insulating layer forming material that covers the back surface side convex portion, and
The method for manufacturing a wiring board laminate according to claim 5, further comprising. With multiple penetrating metal bodies,
A wiring board having a plurality of second openings in a portion corresponding to the penetrating metal body,
Including an insulating layer laminated on the wiring board and containing a cured product of a thermosetting resin,
A wiring board in which a thermosetting resin continuous from the insulating layer fills the space between the penetrating metal body and the second opening while exposing at least the upper surface of the penetrating metal body and the upper surface of the wiring board. Laminated body. With multiple penetrating metal bodies,
Upper and lower wiring boards having a plurality of second openings in the portion corresponding to the penetrating metal body,
It contains an insulating layer that is interposed between the upper and lower wiring boards and contains a cured product of a thermosetting resin.
A wiring board in which a thermosetting resin continuous from the insulating layer fills the space between the penetrating metal body and the second opening while exposing at least the upper surface of the penetrating metal body and the upper surface of the wiring board. Laminated body.

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