JP2007015325A - Molding method for thermally conductive substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a heat conductive substrate by which the mold is not stained and which is high in productivity. <P>SOLUTION: In the molding method of thermal conductive substrate for molding a thermosetting resin composition 1 in a predetermined shape by heating and compressing the thermosetting resin composition 1 having flexibility in a semicured or partially cured state in a mold comprising an upper mold 12, a middle mold 13, and lower mold 11, films 15, 16 are arranged on the faces in which the upper mold 12 and the lower mold 11 of the mold come into contact with the thermosetting resin composition 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a heat conductive substrate used for a high power circuit in an electronic device.

  In recent years, electronic components have been miniaturized, densified, and highly functionalized in accordance with demands for high performance and miniaturization of electronic devices, and these electronic components are mounted on a circuit board at high density. And measures to dissipate heat due to the heat generated by the circuit components have become very important.

  As a technology for improving the heat dissipation of this circuit component, a heat conductive substrate in which an insulating resin filled with a high concentration of a heat conductive filler is formed on an aluminum plate and a copper pattern is further formed thereon has been proposed. (For example, refer to Patent Document 1). FIG. 14A to FIG. 14D are cross-sectional views showing a method for manufacturing this thermally conductive substrate. 14 (a) to 14 (d), 100 is an uncured flexible thermosetting resin composition containing a thermosetting resin and a heat conductive filler as components, and is excellent in heat conductivity. It is composed of an inorganic filler, at least a thermosetting resin, a curing agent, and a curing accelerator, and has flexibility in a semi-cured state.

  As shown in FIG. 14 (a), a heat radiating resin composition 100 laminated to a predetermined thickness on a film 109 made of polyethylene terephthalate (PET) or the like and a heat radiating metal plate 103 are prepared. Next, as shown in FIG. 14B, the heat radiating metal plate 103 and the heat radiating metal plate 103 and the heat are sequentially applied from the end to the heat radiating metal plate 103 through a film 109 using a roller 110. Lamination is performed so that air is not sandwiched between the curable resin composition 100.

  Next, as shown in FIG. 14C, after setting the lead frame 101 on the lower mold 111 for molding, the upper mold 112 is installed at a predetermined position of the lower mold 111. At this time, the lower mold 111 is provided with pilot pins 114 for positioning the lead frame 101.

  Next, as shown in FIG.14 (d), the thermosetting resin composition 100 stuck to the metal plate 103 for heat dissipation produced in FIG.14 (b) was installed in the opening part of the upper mold | type 112, and on it. The middle mold 113 is stacked. Thereafter, the set mold is placed in a hot press and pressurized while being heated to a certain temperature. At this time, the middle mold 113 is lowered, and the thermosetting resin composition 100 is filled in the through grooves 105 of the lead frame 101.

Thereafter, the integrally formed thermally conductive substrate is taken out, and the thermally conductive substrate is manufactured.
JP 2002-355835 A

  However, in the conventional method for producing a heat conductive substrate, the thermosetting resin composition 100 is softened and flows when heated and pressed, so that the thermosetting resin composition 100 is made of the upper mold 112 and the middle mold. It flows into the gap between the upper mold 112 and the terminal portion of the lead frame 101, making it difficult to separate the upper mold 112 and the middle mold 113, or the lower mold 111 and the lead frame 101. In addition, productivity has been impaired because it is necessary to remove the residue of the thermosetting resin composition 100 adhering to the mold after removal.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a method for molding a thermally conductive substrate that does not contaminate the mold and has high productivity.

  In order to solve the above-mentioned conventional problems, the present invention provides the thermosetting resin by heating and pressurizing a thermosetting resin composition having flexibility in a semi-cured or partially cured state in a mold. In the method of molding a heat conductive substrate, which molds the composition into a predetermined shape, the upper mold and the lower mold of the mold are provided with a film on the surface in contact with the thermosetting resin composition, and the mold is soiled. Moreover, it is a molding of a heat conductive heat radiation plate or a substrate with high productivity and a short molding time.

  The invention according to claim 1 is characterized in that the thermosetting resin composition having flexibility in a semi-cured or partially cured state is heated and pressurized in a mold composed of an upper mold, a middle mold and a lower mold. In the method for molding a thermally conductive substrate in which a thermosetting resin composition is molded into a predetermined shape, a film is provided on a surface where the upper mold and the lower mold of the mold are in contact with the thermosetting resin composition. A method for molding a thermally conductive substrate, which can prevent the thermosetting resin composition from flowing into the gap between the upper mold and the middle mold, and eliminates the work of removing the thermosetting resin composition from the mold. be able to.

  According to the second aspect of the present invention, after a thermosetting resin composition having flexibility in a semi-cured state or a partially cured state is placed on a metal plate for heat dissipation, an upper mold, a middle mold, and a lower mold are used. In a method for molding a thermally conductive substrate that is molded into a predetermined shape by heating and pressurizing in a mold and integrated with the metal plate for heat dissipation, an upper mold and a lower mold of the mold A method for molding a thermally conductive substrate, characterized in that a film is provided on a surface of the mold in contact with the thermosetting resin composition, and the thermosetting resin composition can be prevented from flowing into the gap between the upper mold and the middle mold. At the same time, the work of removing the thermosetting resin composition from the mold can be eliminated.

  According to a third aspect of the present invention, a thermosetting resin composition having flexibility in a semi-cured state or a partially cured state is installed on a heat radiating metal plate, and the heat curable resin composition is used for the heat radiation. After laminating the lead frame on the surface where the metal plate is not installed, the thermosetting resin composition is molded into a predetermined shape by heating and pressurizing in a mold composed of an upper mold, a middle mold and a lower mold. In addition, in the method for molding a heat conductive substrate integrated with the metal plate for heat dissipation and the lead frame, a film is provided on a surface where the upper mold and the lower mold of the mold are in contact with the thermosetting resin composition. A method of molding a thermally conductive substrate that can prevent the thermosetting resin composition from flowing into the gap between the upper mold and the middle mold, and remove the thermosetting resin composition from the mold. Can be eliminated.

  Invention of Claim 4 is a shaping | molding method of the heat conductive board | substrate as described in any one of Claims 1-3 characterized by the shape of a film being larger than a heat conductive board | substrate, A film is By having a larger area than the thermosetting resin composition, it is possible to prevent the thermosetting resin composition from contacting and adhering to the mold.

  Invention of Claim 5 uses the film which provided the recessed part which accommodates a thermosetting resin composition in the center part, The heat conductive board | substrate as described in any one of Claims 1-3 characterized by the above-mentioned. In this molding method, wrinkles are formed on the surface of the thermosetting resin composition when the film is pressed with the upper mold, and the surface of the thermosetting resin composition can be prevented from becoming uneven.

  The invention according to claim 6 is characterized in that after the films are laminated, an upper mold of the mold is placed, and then the middle mold of the mold is lowered and heated and pressed in the mold. The method for molding a thermally conductive substrate according to any one of the above, wherein the heat treatment resin composition is first lowered by pressing the lower mold with the upper mold at the periphery where the thermosetting resin composition is unnecessary, and then lowering the middle mold. It is possible to prevent the curable resin composition from overflowing to the periphery.

  The invention according to claim 7 is the method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the film has a thickness of 10 μm or more and 100 μm or less. When the film is wrinkled when it is pressed with the middle mold and the film thickness becomes non-uniform, it can be pressed to such an extent that its influence can be ignored.

  Invention of Claim 8 is a shaping | molding method of the heat conductive board | substrate as described in any one of Claims 1-3 by which the mold release process is performed to the at least single side | surface of a film, By making the surface on which the mold release treatment has been performed on the thermosetting resin composition side, a film attached to the thermosetting resin composition at the time of molding integration can be easily taken.

  The invention according to claim 9 is the method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the film has elasticity, and stabilization of integral molding Can be achieved.

  The invention according to claim 10 is the molding of the thermally conductive substrate according to any one of claims 1 to 3, wherein the film is one of polyethylene resin, polypropylene resin, or fluorine resin. Even if these materials are thin, they are highly stretchable, resistant to tearing, heat resistant, and capable of forming a releasable film, and can only stabilize the molding integration. In addition, there are many commercially available films, and cost reduction can be achieved.

  The invention according to claim 11 is characterized in that an adhesive is applied to a surface of at least one film that does not contact the mold. This is a method for molding a substrate. When the film adheres to a heat-dissipating metal plate or lead frame, the thermosetting resin composition cannot enter the interface between the film and the film, and the surface of the film is thermoset. It is possible to prevent the resin composition from becoming dirty.

  Invention of Claim 12 takes out the shape | molded heat conductive board | substrate from a metal mold | die, and heats it in a thermostat, The heat conductive board | substrate of any one of Claims 1-3 characterized by the above-mentioned. This is a molding method. According to this method, the molding process that cannot be performed in large quantities at once is performed in a relatively short time by molding up to semi-curing, and the subsequent curing by the polymerization reaction of the epoxy resin should be put in a constant temperature furnace in large quantities. Therefore, production efficiency can be increased.

  Invention of Claim 13 takes out the shape | molded heat conductive board | substrate from a metal mold | die, and heats in a thermostat while pressurizing, The heat conduction as described in any one of Claims 1-3 characterized by the above-mentioned. This is a method for molding a flexible substrate, and by this method, the epoxy resin is cured while crushing the air sandwiched between the lead frame and the thermosetting resin composition by pressurization, so that the expansion of the air layer due to temperature rise is prevented. It is possible to prevent the heat conduction efficiency from being lowered.

  The invention according to claim 14 is the method for molding a thermally conductive substrate according to any one of claims 1 to 3, characterized in that the upper die and the middle die are integrally structured. The mold structure can be simplified and the process can be simplified.

  The invention according to claim 15 is the method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the mold is opened in a semi-cured state at the time of molding. This can be done in a short time and can increase productivity.

  The invention according to claim 16 is the method for molding a thermally conductive substrate according to any one of claims 1 to 3, characterized in that the molding is performed in a vacuum atmosphere of 50000 Pa or less. Indentation occurs on the surface of the thermosetting resin composition due to air bubbles sandwiched between the curable resin composition, or air is caught between the thermosetting resin composition and the lead frame or the metal plate for heat dissipation, It is possible to prevent the heat conduction efficiency from being lowered.

  The invention according to claim 17 is characterized in that one or more protrusions are provided on the surface of the mold facing the thermosetting resin composition that does not expose the metal plate for heat dissipation. The method for molding a thermally conductive substrate according to claim 1, wherein a tension is applied to the film as a result of the thermosetting resin composition flowing to the base of the projection with respect to the film raised by the projection at the time of molding. Occurrence can be prevented.

  The invention according to claim 18 is characterized in that, when the thermosetting resin composition is laminated on the lead frame, an upper mold of the mold is used for positioning the thermosetting resin composition. This is a molding method, in which the upper mold is set in the lower mold and then the thermosetting resin composition is pasted in the hole for the middle mold provided in the upper mold, or the thermosetting resin composition is charged. As a result, they can be stacked at a predetermined position. Then, after removing the upper mold, the film is laminated.

  According to the nineteenth aspect of the present invention, in the case of laminating a thermosetting resin composition on a heat radiating metal plate on the lead frame, the protrusion provided on the lower mold of the mold is formed on the heat radiating metal plate. The method for molding a thermally conductive substrate according to claim 3, wherein the positioning is performed by putting it in a hole provided in the heat sink, and the thermosetting resin composition is applied to the heat radiating metal plate in the lower mold. After setting the pasted material, the film can be laminated with the heat dissipating metal plate as a reference and then the upper die can be set. Therefore, the upper die can be easily laminated at a predetermined position without using the jig instead.

  According to the twentieth aspect of the present invention, when the lead frame is installed in the mold, at least two or more reference holes provided in the mold are provided in at least two or more reference holes provided in the outer frame of the lead frame. 4. The method of molding a thermally conductive substrate according to claim 3, wherein the position of the lead frame can be easily maintained.

  The invention according to claim 21 is characterized in that one or more protrusions are provided on the surface of the mold facing the lead frame at a portion where the lead frame does not exist. This is a method for molding a thermally conductive substrate, and the film is raised by the protrusions at the time of molding, so that the thermosetting resin composition flows to the base of the protrusions, thereby applying tension to the film and preventing sagging and wrinkles. be able to.

  Since the manufacturing method of the heat conductive substrate of the present invention can be made with a mold having an inexpensive and simple structure, it is possible to realize a method for forming a heat conductive substrate with a high productivity and a short mold time, without the mold being soiled. Can do.

(Embodiment 1)
Hereinafter, a method for molding a thermally conductive substrate in Embodiment 1 of the present invention will be described with reference to the drawings.

  FIG. 1A is a plan view of a thermally conductive substrate in Embodiment 1 of the present invention, and FIG. 1B is a structural cross-sectional view. 2-7 is sectional drawing for demonstrating the shaping | molding method of a heat conductive board | substrate.

  1A and 1B, the lead frame 2 is made of a metal such as aluminum, copper, silver, or iron. In the first embodiment, a copper plate having a thickness of 0.5 mm is used. In addition, you may perform an anticorrosion process as needed.

  The lead frame 2 has a predetermined pattern 4 and a through groove 5 by press processing, etching processing, laser processing, or the like, and is provided with a connection terminal 6, an outer frame 7, and a positioning hole 8.

  In addition, the plane of the lead frame 2 to be joined to the thermosetting resin composition 1 in a subsequent process is roughened to improve adhesion. Reference numeral 3 denotes a heat radiating metal plate, which is made of aluminum, copper, or an alloy containing them as a main component, and in the first embodiment, an aluminum plate having a thickness of 1 mm is used.

Reference numeral 1 denotes a thermosetting resin composition, which is made of a thermally conductive filler made of an inorganic material, a thermosetting resin, a curing agent, a curing accelerator, and a pregel material. The inorganic filler preferably contains at least one selected from Al ₂ O ₃ , MgO, SiO ₂ , BN, and AlN.

  This inorganic filler has a shape close to a sphere, and its diameter is 0.1 to 100 μm. The inorganic filler is filled in a high concentration of 70 to 95% by weight in order to increase the thermal conductivity. And as this thermosetting resin, it is preferable to contain at least 1 type of resin among an epoxy resin, a phenol resin, and cyanate resin.

  Further, a thermoplastic resin powder is mixed as a pregel material, and the thermoplastic resin powder swells by absorbing the liquid component of the liquid curable composition, and the thermosetting resin composition 1 as a whole is solid. Is shown.

In the first embodiment, an epoxy resin is used as the thermosetting resin, and two types of Al ₂ O ₃ having an average particle diameter of 3 μm and 12 μm are mixed as the inorganic filler. Because it can this large and small types of Al ₂ O ₃ is filled in the small particle size in the gap Al ₂ O ₃ of large particle size by using Al ₂ O ₃ particle size, Al ₂ O ₃ in the first embodiment In a high concentration up to nearly 90% by weight. As a result, the thermosetting resin composition 1 having a high thermal conductivity of 3 W / mK was obtained.

  Next, a method for molding a thermally conductive substrate in the first embodiment will be described with reference to FIGS.

  As shown in FIG. 2, a heat radiation metal plate 3 prepared by laminating a thermosetting resin composition 1 sheeted to a predetermined thickness on a film 9 is prepared. Examples of methods for forming the thermosetting resin composition 1 into a sheet include a doctor blade method, a coater method, an extrusion molding method, and a rolling method. In the first embodiment, the thermosetting resin composition 1 is formed into a 1.4 mm thick sheet on the film 9 using PET by an extrusion molding method. In particular, when the thermosetting resin composition 1 is laminated on the heat radiating metal plate 3, the important point is that the air is not caught at the interface between the heat radiating metal plate 3 and the thermosetting resin composition 1. That is what you have to do. Therefore, for example, as shown in FIG. 3, the heat-dissipating metal plate 3 and the thermosetting resin composition 1 are sequentially applied from the end to the heat-dissipating metal plate 3 through the film 9 using a roller 10. The resin composition 1 was laminated so as not to sandwich air.

  Here, although the thermosetting resin composition 1 is supplied as a sheet on the film 9, the thermosetting resin composition 1 may be directly formed into a sheet and supplied onto the metal plate 3 for heat dissipation. good. Moreover, as a method of laminating the thermosetting resin composition 1 on the heat radiating metal plate 3, a dispenser, a monopump, or The required amount of the thermosetting resin composition 1 may be directly applied using an extrusion molding machine or the like.

  Next, as shown in FIG. 4, a film 15 is disposed on the lower mold 11, and the lead frame 2 is disposed thereon. It is a feature of the present invention that the film 15 is arranged in the mold as described above, whereby the thermosetting resin composition 1 can be prevented from flowing into the gap in the mold, and the mold The operation of removing the residue of the thermosetting resin composition 1 attached to the mold can be eliminated. The size of the film 15 is preferably larger than the shape of the opening of the upper mold 12. This is because the thermosetting resin composition 1 can be prevented from coming into contact with the lower mold 11 and adhering to the mold when the thermosetting resin composition 1 flows and fills in the mold during the subsequent pressurization. is there. Further, if the thickness of the film 15 is too thin, the strength of the film 15 becomes weak, the film 15 may be torn and the thermosetting resin may overflow, and if it is too thick, the shape of the desired thermally conductive substrate may be. It becomes difficult to obtain. In addition, the moldability is deteriorated due to the formation of wrinkles. Therefore, the thickness of the film 15 is desirably 10 μm or more and 100 μm or less. Thereby, even when wrinkles occur in the film 15 when the upper mold 12 or the middle mold 13 is pressed, the influence can be suppressed to a level that can be ignored.

  The film 15 is preferably made of a material that is highly stretchable and is not easily torn from the viewpoint of improving the efficiency of moldability and workability, and it is preferable to use a polyethylene resin, a polypropylene resin, or a fluorine resin. In the first embodiment, stretch type polypropylene (OPP) is used. Thereby, while being able to aim at stability of molding integration, since it is what is marketed, cost control can be aimed at.

  Further, it is more preferable that a release treatment is performed on at least one surface of the film 15, in this case, the surface in contact with the thermosetting resin composition 1. Thus, after the thermosetting resin composition 1 is molded and cured, the film 15 can be easily peeled off.

  Alternatively, an adhesive may be applied to the surface of the film 15 that is in contact with the lead frame 2. By doing so, the lead frame 2 and the film 15 are in close contact with each other, and the thermosetting resin composition 1 does not enter between the lead frame 2 and the film 15 at the time of molding. 1 can prevent contamination. Moreover, you may make the film 15 shape | mold a recessed part into which the thermosetting resin composition 1 enters beforehand. This prevents the film 15 from wrinkling due to the thickness of the thermosetting resin composition 1, and prevents the thermosetting resin composition 1 from being unevenly thick due to wrinkles after being pressed by a mold. It is.

  Next, pilot pins 14 are provided on the lower die 11 in order to provide protrusions for positioning the lead frame 2. And it is preferable to provide at least two or more positioning pins.

  Apart from this, a guide post for determining the positions of the lower mold 11 and the upper mold 12 is actually provided as a basic mold structure, but the description thereof is omitted here. Thus, the position of the lead frame 2 can be easily held by providing two or more positioning pins.

  Next, as shown in FIG. 5, the thermosetting resin composition 1 attached to the heat radiating metal plate 3 is placed on the lead frame 2. The positioning of the heat radiating metal plate 3 at this time is performed by inserting the pins 17 provided on the lower mold 11 into holes formed in the heat radiating metal plate 3. Further, a film 16 is placed thereon. The size and material of the film 16 are preferably the same as or equivalent to those of the film 15.

  Moreover, as a positioning method of the heat radiating metal plate 3, when a hole is not formed in the heat radiating metal plate 3, a thermosetting resin composition attached to the heat radiating metal plate 3 on the lead frame 2. Before the 1 is installed, the upper mold 12 is set on the lower mold 11, and the thermosetting resin composition 1 attached to the heat radiating metal plate 3 is installed in the hole in which the middle mold 13 is inserted to perform positioning. The upper mold 12 is once removed and then the film 16 is set.

  Next, as shown in FIG. 6, the upper mold 12 is installed so as to be pressed through the films 15 and 16 located above and below the lead frame 2.

  Thereafter, as shown in FIG. 7, after the middle mold 13 is stacked on the heat radiating metal plate 3, it is placed in a hot press and pressurized while being heated to a certain temperature. At this time, the middle mold 13 is lowered, and the thermosetting resin composition 1 is filled in a portion surrounded by the through groove 5 and the upper mold 12 and the lower mold 11 of the lead frame 2, and a predetermined heat conductive substrate is formed. Can be molded into a shape. After the films 15 and 16 are laminated in this manner, the upper mold 12 is placed, and then the middle mold 13 is lowered and heated and pressurized in the mold so that the thermosetting resin composition 1 is placed around the upper mold 12. It can prevent overflowing.

  Thereafter, when the thermosetting resin composition 1 starts to be in a semi-cured state, the mold is opened, the films 15 and 16 are taken out, cooled to room temperature, and then the films 15 and 16 are removed and placed in a thermostatic bath. To heat the thermosetting resin completely. Since an epoxy resin was used as the thermosetting resin, the curing condition was heated at 170 ° C. for 3 hours. By molding by such a method, the production efficiency can be improved.

  Further, when the resin is completely cured, it may be cured while being pressurized in a constant temperature furnace. Thereby, since the epoxy resin is cured while crushing the air sandwiched between the lead frame 2 and the thermosetting resin composition 1, it is possible to prevent the expansion of the air layer due to the temperature rise and to prevent the heat conduction efficiency from being lowered. be able to.

  Molding is usually performed at atmospheric pressure, but at the initial stage where the thermosetting resin composition 1 is set in a mold and molded, a film between the lead frame 2 and the thermosetting resin composition 1 or a film. 15 and 16 and the thermosetting resin composition 1 may bite air, and the surface of the thermosetting resin composition 1 is dented or air bubbles are formed at the interface with the lead frame 2 to conduct heat. In some cases, the efficiency may deteriorate or the pressure resistance may deteriorate. In this case, it is preferable to carry out in a vacuum atmosphere of 50000 Pa or less at the initial stage of molding. Thereby, the adhesiveness of the thermosetting resin composition 1 and the lead frame 2 increases, and it can prevent that heat conduction efficiency falls.

  In addition, in the metal mold | die used for shaping | molding, you may shape | mold using the metal mold | die with which the upper mold | type 12 and the intermediate mold 13 were united. As a result, the mold structure can be simplified, and the process can be simplified. However, when this thermosetting resin composition 1 is pressurized, it is necessary to affix the thermosetting resin composition 1 to the heat radiating metal plate 3 in a well-balanced manner so as to spread uniformly over the heat radiating metal plate 3. is there.

  Further, when the heat radiating metal plate 3 is large, or depending on the pattern shape of the lead frame 2, sagging occurs in the film 15 due to sagging in the relatively large gap of the lead frame 2, and the thermosetting resin composition 1. The surface may have irregularities such as wrinkles, which may cause poor appearance. In such a case, by providing convex protrusions in the gaps of the lead frame 2 on the surface of the lower mold 11 facing the lead frame 2, the film 15 raised by the convex protrusions during pressure molding is formed. On the other hand, when the thermosetting resin composition 1 flows to the base of the protrusion, it is possible to realize molding that suppresses the occurrence of sagging and wrinkles.

(Embodiment 2)
Hereinafter, a method for molding a thermally conductive substrate in Embodiment 2 of the present invention will be described with reference to the drawings.

  FIG. 8 is a cross-sectional view of a thermally conductive substrate according to Embodiment 2 of the present invention, and FIGS. 9 to 13 are cross-sectional views showing a method for molding a thermally conductive substrate.

  In FIG. 8, a thermosetting resin composition 1 having high thermal conductivity is laminated on the metal plate 3 for heat dissipation. The material used for this thermosetting resin composition 1 was the same as that of the first embodiment. And heat generating parts, such as a semiconductor power element and a transformer, are mounted on the opposite surface of the thermosetting resin composition 1 to which the heat radiating metal plate 3 is not joined, and the heat generated by these heat generating parts has high thermal conductivity. It can transmit to the metal plate 3 for heat dissipation through the thermosetting resin composition 1 which has, and can suppress the temperature rise of a heat-emitting component.

  Next, a method for molding a thermally conductive substrate in the second embodiment will be described with reference to FIGS.

  As shown in FIG. 9, a laminate of the sheet of thermosetting resin composition 1 formed into a predetermined thickness on a film 9 and a heat radiating metal plate 3 are prepared, and then thermosetting as shown in FIG. The resin composition 1 is laminated on the metal plate 3 for heat dissipation. Up to this point, the same method as in the first embodiment was used.

  Next, as shown in FIG. 11, the film 15 is arrange | positioned on the lower mold | type 11, and the thermosetting resin composition 1 laminated | stacked on the metal plate 3 for heat dissipation is arrange | positioned on it. At this time, the heat dissipating metal plate 3 was on the bottom, and the thermosetting resin composition 1 was on the top.

  Although it is possible to arrange them in the opposite direction, it is preferable from the viewpoint of workability that the thermosetting resin composition 1 is placed on the upper side in consideration of transportation and the lamination method of the thermosetting resin composition 1. And positioning of the metal plate 3 for heat dissipation can be performed by throwing the pin 17 provided in the lower mold | type 11 in the hole opened in the metal plate 3 for heat dissipation. Thereby, the metal plate 3 for heat dissipation can be positioned and the thermosetting resin composition 1 and the film 15 can be laminated | stacked on a predetermined position on the basis of the metal plate 3 for heat dissipation.

  Then, the film 16 is arrange | positioned further on these laminated bodies. The size, material, etc. of the film 16 can be the same as or equivalent to that of the film 15.

  As described above, the use of the films 15 and 16 in the mold is a feature of the present invention, which can prevent the thermosetting resin composition 1 from flowing into the gaps in the mold, The operation of removing the residue of the thermosetting resin composition 1 attached to the mold can be eliminated.

  Next, as shown in FIG. 12, the upper mold 12 is installed at a predetermined position of the lower mold 11, and then the middle mold 13 is placed on the thermosetting resin composition 1 in the opening of the upper mold 12. Is done.

  In addition, it is also possible to arrange the thermosetting resin composition 1 in an opening provided in the upper mold 12 after the upper mold 12 is installed. By doing so, the upper mold 12 is thermosetting. It becomes positioning of the resin composition 1, and it becomes easy to laminate | stack the thermosetting resin composition 1 in a predetermined position.

  Next, as shown in FIG. 13, the mold placed as described above is placed in a hot press and pressurized while being heated to a certain temperature. At this time, the middle mold 13 is pressed down and lowered, the thermosetting resin composition 1 spreads over the upper surface of the metal plate 3 for heat dissipation, and is filled in a portion surrounded by the upper mold 12 and the lower mold 11, It is molded into a predetermined heat conductive substrate shape.

  Then, when the thermosetting resin composition 1 starts to be in a semi-cured state, the mold is opened, the films 15 and 16 are taken out, cooled to room temperature, and then the films 15 and 16 are removed and placed in a thermostatic bath. The thermosetting resin composition 1 is completely cured by heating. In the case of this hardening, you may make it harden | cure, pressurizing within a thermostat. The curing conditions were the same as in the first embodiment.

  Thus, at the time of shaping | molding, it can shape | mold in a short time and can aim at productivity improvement by opening a metal mold | die with the thermosetting resin composition 1 in a semi-hardened state.

  Moreover, when the metal plate 3 for heat dissipation is large, or depending on how the film 16 is stretched, the film 16 sags and wrinkles are generated, and irregularities such as wrinkles are generated on the surface of the thermosetting resin composition 1, resulting in poor appearance. It may become.

  In such a case, by providing convex protrusions in the gaps of the lead frame 2 on the surface of the lower mold 11 facing the lead frame 2, the film 15 raised by the convex protrusions during pressure molding is formed. On the other hand, when the thermosetting resin composition 1 flows to the base of the protrusion, it is possible to realize molding that suppresses the occurrence of sagging and wrinkles.

  By providing a protrusion on at least one portion on the surface of the upper mold 12 facing the thermosetting resin composition 1, the thermosetting resin composition 1 is formed on the film 16 raised by the protrusion during molding. By flowing to the root of the film, tension is applied to the film 16, and the occurrence of sagging and wrinkles can be suppressed. Further, by providing the recess of the thermosetting resin composition 1 made by this protrusion slightly larger than the shape of the electronic component and providing it at the mounting position, it can be applied to positioning when mounting the component. It becomes possible to improve workability when mounting components on the conductive substrate using an adhesive.

  The method for molding a thermally conductive substrate according to the present invention can be performed with a mold having an inexpensive and simple structure, the mold is not soiled, and it is possible to mold a highly conductive thermally conductive heat radiation plate or substrate with a short molding time. It is useful for heat dissipation of electronic components that become high temperature during operation of electronic equipment.

(A) The top view of the heat conductive board | substrate in Embodiment 1 of this invention, (b) same sectional drawing Sectional drawing for demonstrating the molding method Cross section Cross section Cross section Cross section Cross section Sectional drawing of the heat conductive board | substrate in Embodiment 2 of this invention. Sectional drawing for demonstrating the molding method Cross section Cross section Cross section Cross section (A) Sectional drawing for demonstrating the shaping | molding method of the conventional heat conductive board | substrate, (b) The same sectional view, (c) The same sectional view, (d) The same sectional view

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermosetting resin composition 2 Lead frame 3 Metal plate for heat dissipation 4 Pattern 5 Through groove 6 Connection terminal 7 Outer frame 8 Positioning hole 9 Film 10 Roller 11 Lower mold 12 Upper mold 13 Medium mold 14 Pilot pin 15 Film 16 Film 17 Pin 18 mold

Claims (21)

A thermosetting resin composition having flexibility in a semi-cured or partially cured state is heated and pressed in a mold composed of an upper mold, a middle mold, and a lower mold, whereby the thermosetting resin composition is A method for molding a thermally conductive substrate, wherein a film is provided on a surface of the upper and lower molds in contact with the thermosetting resin composition, in the method for molding a thermally conductive substrate to be molded into a shape. By placing a flexible thermosetting resin composition on a metal plate for heat dissipation in a semi-cured or partially cured state, and then heating and pressurizing in a mold consisting of an upper mold, a middle mold and a lower mold In the method for molding a thermally conductive substrate that is molded into a predetermined shape and integrated with the heat radiating metal plate, the upper mold and the lower mold of the mold are a thermosetting resin composition. A method for molding a thermally conductive substrate, characterized in that a film is provided on a contact surface. A thermosetting resin composition having flexibility in a semi-cured state or a partially cured state is placed on a heat radiating metal plate, and the heat curable resin composition has a surface on which the heat radiating metal plate is not placed. After laminating the lead frame, the thermosetting resin composition is molded into a predetermined shape by heating and pressing in a mold composed of an upper mold, a middle mold, and a lower mold, and the heat radiating metal plate and the lead In the method for molding a thermally conductive substrate integrated with a frame, a film is provided on the surface of the mold where the upper mold and the lower mold are in contact with the thermosetting resin composition. The shape of a film is larger than a heat conductive board | substrate, The shaping | molding method of the heat conductive board | substrate as described in any one of Claims 1-3 characterized by the above-mentioned. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein a film provided with a recess for housing the thermosetting resin composition in the center is used. The heat according to any one of claims 1 to 3, wherein the upper mold of the mold is placed after the films are laminated, and then the middle mold of the mold is lowered and heated and pressurized in the mold. A method for forming a conductive substrate. The thickness of a film is 10 micrometers or more and 100 micrometers or less, The shaping | molding method of the heat conductive board | substrate as described in any one of Claims 1-3 characterized by the above-mentioned. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein a release treatment is performed on at least one surface of the film. The method for molding a thermally conductive substrate according to claim 1, wherein the film has stretchability. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the film is one of a polyethylene resin, a polypropylene resin, or a fluorine resin. The method for molding a thermally conductive substrate according to claim 1, wherein an adhesive is applied to a surface of at least one film that does not contact the mold. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the molded thermally conductive substrate is taken out of the mold and heated in a constant temperature furnace. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the molded thermally conductive substrate is taken out of the mold and heated in a constant temperature furnace while being pressurized. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the mold is a mold in which an upper mold and a middle mold have an integral structure. 4. The method for molding a thermally conductive substrate according to claim 1, wherein the mold is opened in a semi-cured state at the time of molding. The method for molding a thermally conductive substrate according to any one of claims 1 to 3, wherein the molding is performed in a vacuum atmosphere of 50000 Pa or less. The molding of a thermally conductive substrate according to claim 2, wherein one or more protrusions are provided on the surface of a mold facing a thermosetting resin composition that does not expose a metal plate for heat dissipation. Method. The method for molding a thermally conductive substrate according to claim 3, wherein when the thermosetting resin composition is laminated on the lead frame, an upper mold of the mold is used for positioning. When laminating a heat radiation resin plate with a thermosetting resin composition on a lead frame, by placing a protrusion provided on the lower mold of the mold into a hole provided in the heat dissipation metal plate, 4. The method for molding a thermally conductive substrate according to claim 3, wherein the positioning is performed. When the lead frame is installed in the mold, it is positioned and held in at least two or more reference holes provided in the outer frame of the lead frame by at least two or more protrusions provided in the mold. The method for molding a thermally conductive substrate according to claim 3. 4. The method for molding a thermally conductive substrate according to claim 3, wherein one or more protrusions are provided on a surface of the mold facing the lead frame at a portion where the lead frame does not exist.

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