TW202021433A - Method for manufacturing metal base circuit substrate - Google Patents

Abstract

The purpose of the present invention is to obtain a method for manufacturing a metal base circuit substrate with which it is possible to improve the processing speed even for a thicker circuit pattern compatible with a larger current. This invention comprises: a punching step for punching out, all at once, a circuit pattern 3 from a material board, said circuit pattern 3 having a plurality of independent parts 3a for a circuit; and a heat transfer step in which the plurality of punched-out independent parts 3a for a circuit are indirectly or directly transferred all at once from the punching positions thereof onto an insulation layer 7 present on a metal substrate 5 to form a circuit pattern 3. Even for a thicker circuit pattern compatible with a larger current, processing speed can be improved, the cost can be reduced, misalignment of the circuit pattern 3 can be minimized, and short-circuiting of the current can be prevented.

Description

Method for manufacturing metal base circuit board

The present invention relates to a method of manufacturing a metal-based circuit board, which includes a circuit pattern on a flat-plate-shaped or heat sink-shaped metal substrate through an insulating layer.

In recent years, the demand for large current of power devices has been increasing, and at the same time, the demand for cost reduction of semiconductors has also increased. That is, the development requirements for metal-based circuit boards that can handle large currents at low prices are increasing.

Patent Document 1 describes a conventional metal base circuit board. This metal-based circuit board is an unhardened insulating layer coated on a metal substrate, and a circuit pattern is attached to the insulating layer, and the insulating layer is heated and hardened while pressing the circuit pattern.

However, when crimping the circuit pattern, there is a problem that the circuit pattern is misaligned.

To solve this problem, there is a method of forming the circuit pattern 103 of the metal base circuit board 100 shown in FIG. 11 using the semi-finished product 101 of FIG. 12. The semi-finished product 101 of FIG. 12 is formed by, for example, etching processing. The semi-finished product 101 of the circuit pattern supports the circuit pattern 103 to the frame 107 via the positioning bracket 105.

Then, the semi-finished product 101 of the circuit pattern 103 is attached to the uncured insulating layer coated on the metal substrate, and the insulating layer is cured by heat treatment performed simultaneously with the pressing. Thereafter, the frame 107 and the like are removed.

Therefore, there is an advantage that the problem of the misalignment of the circuit pattern 103 can be improved by the bracket 105 and the frame 107 existing at the time of crimping.

However, because the floating island-shaped portion 109 exists in the circuit pattern 103A of the metal-based circuit board 100A shown in FIG. 13, the floating island-shaped portion 109 cannot be supported on the frame by the bracket 105 like the semi-finished product 101A of FIG. 14. Question 107.

In addition, in the case of such a conventional manufacturing method, a thick copper pattern with a thickness exceeding 0.5 mm in response to the demand for large current will slow down the etching process and the like, and because it is required as a frame 107 that is not required for the circuit pattern 103 And support 105, so there is a limit to the need for cost reduction.

On the other hand, as a manufacturing method capable of suppressing pattern misalignment without using a frame, there is a method described in Patent Document 1 using an adhesive film.

The above method is to sequentially perform the following steps: a step of forming a circuit pattern on the adhesive layer of the adhesive film by a conductor; a step of forming an insulating layer by coating an insulating material on the circuit forming surface of the adhesive film; And the step of peeling the adhesive film to expose the circuit to the surface of the insulating layer.

Therefore, there is no unnecessary frame or bracket as a circuit pattern, and it can respond to a certain cost reduction requirement.

However, because the circuit pattern is formed on the adhesive film by etching or screen printing, the thick copper pattern that responds to the demand for large current will slow down the processing and other speeds, and also has a limit to the cost reduction requirement. .

[Conventional Technical Literature]

[Patent Literature]

[Patent Literature 1] WO2016/125650A1;

[Patent Document 2] Japanese Patent Laid-Open No. 2003-338678.

The problem to be solved is that it is impossible to correspond to the existence of a floating island-shaped portion in the circuit pattern, and the thick circuit pattern in response to the demand for large current will slow down the processing speed, and there is a limit to the cost reduction requirement.

An object of the present invention is to be able to respond even if there are floating island-shaped portions in the circuit pattern, and even a thick circuit pattern that responds to the demand for higher current can increase the processing speed and increase the response to the demand for cost reduction.

In order to achieve the foregoing object, the most important feature of the method for manufacturing a metal-based circuit board of the present invention is to include the following steps: a stamping step, which simultaneously stamps out a circuit pattern having a plurality of independent parts for circuits from a material plate; and a transfer step, Separate parts for the plurality of circuits punched out above It is transferred indirectly to the insulating layer on the metal substrate from its stamping position and used as the aforementioned circuit pattern, or directly transferred to the insulating layer on the metal substrate and used as the aforementioned circuit pattern.

According to the manufacturing method of the metal-based circuit board of the present invention, because the circuit pattern is stamped together, and each circuit-use independent part is transferred indirectly from the stamping position at the intermediate transfer receiving part, or directly transferred to the metal substrate Insulation layer, so even if there is a floating island shape in the circuit pattern, and even a thick circuit pattern in response to the demand for higher current can increase the processing speed and increase the response to the demand for cost reduction. In addition, the misalignment of the circuit pattern can be suppressed, and short circuit of current can be prevented.

1. 1A‧‧‧Metal base circuit board

3‧‧‧ circuit pattern

3a‧‧‧Independent Division for Circuit

5, 5A‧‧‧Metal substrate

5a‧‧‧Protrusion

7‧‧‧Insulation

11‧‧‧ Upper mold

13‧‧‧ Die

15‧‧‧Upper module board

17‧‧‧Punch fixing plate

19a‧‧‧Punch

21‧‧‧Remove template

23‧‧‧Ejection unit, coil spring

24‧‧‧Lower module board

25‧‧‧ template

25a‧‧‧die

27‧‧‧ ejected

27a‧‧‧selling

29‧‧‧Intermediate Transfer Accepting Department

31‧‧‧Support plate (component of intermediate transfer receiving section)

33‧‧‧ Adhesive sheet (component of intermediate transfer receiving section)

S1‧‧‧Stamping steps

S2‧‧‧Intermediate transfer steps

S3‧‧‧Heating transfer procedure

W‧‧‧copper plate (material plate)

FIG. 1 is a schematic plan view of a metal-based circuit board. (Example 1)

2 is a schematic cross-sectional view of a metal-based circuit board using a flat-shaped metal substrate. (Example 1)

3 is a schematic cross-sectional view of a metal base circuit board using a metal substrate in the shape of a heat sink. (Example 1)

4 is a schematic cross-sectional view of a pressurizing device. (Example 1)

FIG. 5 is a schematic cross-sectional explanatory view showing a pressing step and an operation of pressing a circuit pattern. (Example 1)

FIG. 6 is a schematic plan view of the circuit pattern stamped and held by the template in the stamping step. (Example 1)

7 is a schematic cross-sectional explanatory view showing an intermediate transfer step and an operation of transferring the circuit pattern to the adhesive sheet of the support plate. (Example 1)

FIG. 8 is a schematic bottom view showing a state where the circuit pattern is transferred to the adhesive sheet of the support plate in the middle transfer step. (Example 1)

9 is a schematic cross-sectional explanatory view showing the transfer step and the operation of transferring from the adhesive sheet of the support plate to the insulating layer of the metal substrate. (Example 1)

FIG. 10 is a schematic cross-sectional explanatory diagram for explaining the pressure heating process. (Example 1)

11 is a plan view of a metal base circuit board having a circuit pattern without a floating island-shaped portion.

12 is a plan view showing a state in which a circuit pattern that does not have a floating island-shaped portion is supported on a frame. (Conventional example)

13 is a plan view of a metal base circuit board provided with a circuit pattern having a floating island-shaped portion.

14 is a plan view showing a state where a circuit pattern having a floating island-shaped portion is supported on a frame.

The present invention achieves the following object in a later-described manner: Even a thick circuit loop that responds to the demand for larger currents can increase the processing speed, and can increase the response to the demand for cost reduction.

The method for manufacturing a metal-based circuit board of this embodiment includes: a stamping step, a circuit pattern having a plurality of independent parts for circuits is stamped out from a material plate; and a heat transfer step as a transfer step, the plurality of stampings are finished The circuit independent part is transferred indirectly from its stamping position to the insulating layer on the metal substrate and used as the aforementioned circuit pattern, or transferred directly to the insulating layer on the metal substrate and used as the aforementioned circuit pattern.

It may be configured to include an intermediate transfer step, hold the stamping position, and transfer the plurality of circuit independent parts to the intermediate transfer receiving part; after the stamping step, transfer the plurality of circuit independent parts to The intermediate transfer receiving unit performs the transfer in the transfer step by the intermediate transfer receiving unit to perform the indirect transfer.

It may be configured that a supporting plate provided with an adhesive sheet on the surface is used as the intermediate transfer receiving portion of the intermediate transfer step, and the intermediate transfer is performed, and the plurality of independent parts for circuits are attached to the adhesive sheet together.

It may be configured that the adhesive sheet is a thermal release sheet, and the adhesive force of the adhesive sheet to the circuit pattern is reduced or lost by heat treatment, whereby the adhesive sheet can be peeled from the circuit pattern on the insulating layer.

(Example)

[Metal base circuit board]

FIG. 1 is a schematic plan view of a metal-based circuit board. 2 is a schematic cross-sectional view of a metal-based circuit board using a flat-shaped metal substrate.

The metal-based circuit board 1 of FIGS. 1 and 2 is provided with a thick circuit pattern 3 in response to a large current demand. This metal base circuit board 1 is provided with a circuit pattern 3 on a flat metal substrate 5 through an insulating layer 7.

The circuit pattern 3 is formed of copper, for example, and is formed of a copper material for circuits having a thick copper pattern with a thickness exceeding 0.5 mm. The thickness of the circuit pattern 3 can be variously selected, and the thickness can also be less than 0.5 mm.

The circuit pattern 3 includes a plurality of circuit independent parts 3a that are electrically independent. The configuration of the plurality of independent circuits 3 a is formed in accordance with the required characteristics of the circuit pattern 3.

The insulating layer 7 not only functions to electrically insulate the circuit pattern 3 from the metal substrate 5, but also functions as a bonding agent for bonding the metal substrate 5 and the circuit pattern 3 to each other. Therefore, resin is generally used for the insulating layer 7. In addition, for the high heat build-up of the element mounted on the circuit pattern 3, the insulating layer 7 needs high heat resistance and high heat transfer capability to transmit this heat to the metal substrate 5. Therefore, the insulating layer 7 preferably further contains an inorganic filler.

As the matrix resin of the insulating layer 7, for example, the following resins can be used alone or in combination of two or more types; epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and triazine type epoxy resin; Cyanate resins such as phenol E type cyanate resin, bisphenol A type cyanate resin, phenolic (Novolak) cyanate resin, etc.

The inorganic filler contained in the insulating layer 7 is preferably one having excellent electrical insulation and high thermal conductivity. Examples thereof include aluminum oxide, silicon dioxide, aluminum nitride, boron nitride, silicon nitride, and magnesium oxide. It is preferable to use one or two or more selected from these.

The filling rate of the inorganic filler in the insulating layer 7 can be appropriately set according to the type of inorganic filler. For example, based on the total volume of the parent resin contained in the insulating layer 7 as a reference, it is preferably 85% by volume or less, and more preferably 30 to 85% by volume.

The insulating layer 7 may further contain a coupling agent, a dispersing agent, etc. in addition to the above-mentioned matrix resin and inorganic filler.

Furthermore, an insulating sheet in a semi-hardened state may be used as the insulating layer 7.

The metal substrate 5 is composed of, for example, a single metal or an alloy. As a material of the metal substrate 5, for example, aluminum, iron, copper, aluminum alloy, or stainless steel can be used. The metal substrate 5 may further contain non-metal such as carbon. For example, the metal substrate 5 may contain aluminum combined with carbon. In addition, the metal substrate 5 may have a single-layer structure or a multi-layer structure.

The metal substrate 5 has high thermal conductivity. For example, copper has a thermal conductivity of 370~400W‧m ^-1 ‧K ^-1 , aluminum has a thermal conductivity of 190~220W‧m ^-1 ‧K ^-1 , and iron has a thermal conductivity of 60~80W‧m ^-1 ‧K ^-1 thermal conductivity.

The metal substrate 5 may or may not be flexible. The thickness of the metal substrate 5 is, for example, in the range of 0.2 to 5 mm.

3 is a schematic cross-sectional view of a metal base circuit board using a metal substrate in the shape of a heat sink.

The metal base circuit board 1A using this heat sink-shaped metal substrate 5A has basically the same configuration as the metal base circuit board using the flat-plate metal substrate 5 of FIGS. 1 and 2. On the other hand, in the case of the metal base circuit board 1A, the metal substrate 5A includes a heat dissipation protrusion 5a. The thickness of the flat plate shape excluding the protrusion 5a of the metal substrate 5A is, for example, the same as described above, and is in the range of 0.2 to 5 mm.

[Manufacturing method]

4 is a schematic cross-sectional view of a pressurizing device. FIG. 5 is a schematic cross-sectional explanatory view showing a pressing step and an operation of pressing a circuit pattern. FIG. 6 is a schematic plan view of the circuit pattern stamped and held by the template in the stamping step. 7 is a schematic cross-sectional explanatory view showing an intermediate transfer step and an operation of transferring the circuit pattern to the adhesive sheet of the support plate. FIG. 8 is a schematic bottom view showing a state where the circuit pattern is transferred to the adhesive sheet of the support plate in the middle transfer step. 9 is a schematic cross-sectional explanatory view showing a heating transfer step and an operation of transferring from the adhesive sheet of the support plate to the insulating layer of the metal substrate. FIG. 10 is a schematic cross-sectional explanatory diagram for explaining the pressure heating process.

The method for manufacturing a metal base circuit board according to an embodiment of the present invention includes a stamping step S1, an intermediate transfer step S2, and a heating transfer step S3 as a transfer step.

(Stamping step)

As shown in FIG. 4 and FIG. 5, the stamping step S1 is to perform the following operation: the circuit pattern 3 having a plurality of circuit independent portions 3 a is stamped out from the copper plate W as a material plate.

For this stamping, for example, the pressing device of FIG. 4 is used.

As shown in FIG. 4, the pressing device 9 includes an upper mold 11 and a lower mold 13 as a metal mold.

The upper mold 11 is attached to a pressure mechanism side (not shown), and can be lowered by hydraulic pressure such as hydraulic pressure or mechanical pressure to generate pressure.

The upper die 11 is provided with a punch fixing plate 17 on the upper module plate 15. Plural punches 19a are supported by the punch fixing plate 17. The punch 19a is provided corresponding to the circuit independent part 3a (FIG. 1) of the circuit pattern 3.

A knockout plate 21 is arranged on the tip side of the punch 19a. The mold release plate 21 includes a mold release unit 23 and an auxiliary guide pillar (not shown). Therefore, the stripper plate 21 can be arranged so as to move backward to the punch fixing plate 17 while being guided by the auxiliary guide post. This backward movement is performed against the elastic force of the coil spring 23 of the demolding unit.

The lower mold 13 includes a template 25 and an ejector 27 shown in FIG. 5 on the lower module board 24.

The lower module board 24 is fixed to a substrate (not shown). The lower module board 24 and the upper module board 15 are combined with a guide post 28.

The template 25 is supported on a substrate (not shown), and includes a die 25a corresponding to the punch 19a.

The ejector 27 is supported up and down on the substrate side. The ejector 27 includes an ejector pin 27a, and is fitted to the die 25a. The ejector 27 is configured to be driven up and down with respect to the substrate side by a hydraulic device, an air pressure device, or the like. In the stamping position, the ejector pin 27a is located slightly inside the die 25a than the upper surface of the die plate 25. At this position, the stamped independent circuit part 3a is configured to be held in the die 25a on the ejector pin 27a.

Then, as shown in the left diagram of FIG. 5, for example, a flat rectangular copper plate W is supplied as a material plate between the upper mold 11 and the lower mold 13. For example, if the left-right direction in FIG. 4 is the X direction and the direction perpendicular to the X direction is the Y direction, the copper sheet W is carried in the X direction by the conveying jig. Furthermore, the copper sheet W can also be carried in from the Y direction, and the copper sheet W can also be continuously supplied between the upper die 11 and the lower die 13 as a continuous sheet.

When the upper die 11 is lowered by NC control, the stripper plate 21 is elastically connected to the copper plate W, and then the punch 19a is lowered again to punch out a plurality of circuit independent portions 3a of the circuit pattern 3 from the copper plate W.

As shown in the right diagram of FIG. 5, a plurality of circuit independent portions 3a of the stamped circuit pattern 3 are held within the upper side of the die 25a on the ejector pin 27a.

As shown in FIG. 6, the circuit pattern 3 stamped in a plan view holds a plurality of circuit independent parts 3 a as the stamped position while maintaining the relative position of the circuit pattern 3 within the die 25 as the stamped position.

(Intermediate transfer step)

As shown in FIG. 7, the intermediate transfer step S2 is a step of intermediately transferring the plurality of circuit independent parts 3 a to the intermediate transfer receiving part 29 while maintaining the stamping position. That is, by After step S1, the plurality of independent circuits 3a are intermediately transferred to the intermediate transfer receiver 29, and the intermediate transfer receiver 29 performs a heat transfer step to be described later to perform the indirect transfer.

As shown in FIG. 7, the adhesive sheet 33 provided on the surface of the support plate 31 is used as an example of the intermediate transfer receiving portion 29. Furthermore, the adhesive sheet is also called adhesive film. The plurality of circuit independent portions 3a are maintained at the punching position and pushed out and attached to the adhesive sheet 33 to maintain the relative position of the circuit pattern 3.

The support plate 31 is formed of the same material as the circuit pattern 3, for example. In this embodiment, the support plate 31 is formed of copper in the same way as the circuit pattern 3. By forming the support plate 31 with the same material as the circuit pattern 3, the thermal expansion coefficients of the two can be made uniform. However, the support plate 31 can be formed of a material different from the circuit pattern 3 without considering the coincidence of the thermal expansion coefficients.

The planar shape of the support plate 31 is formed corresponding to the size and shape of the metal substrate 5, for example, in this embodiment, it is formed into a rectangular shape, for example.

The thickness of the support plate 31 is set to 2 to 4 mm. The support plate 31 is required not to be easily deformed during pressure heat treatment. If it is not easy to deform, other thicknesses can also be selected.

In this embodiment, the adhesive sheet 33 is a thermal release sheet. The adhesive force of the adhesive sheet 33 to the circuit pattern 3 is reduced or lost by heat treatment, and the adhesive sheet 33 can be peeled from the circuit pattern 3 on the insulating layer 7.

As the heat-releasing sheet of the adhesive sheet 33, for example, it has a thickness of 0.1 to 0.2 mm and a structure in which two surfaces are adhered. The adhesive on one side of the adhesive sheet 33 to the support plate 31 is peelable after the heat transfer step. The adhesive on the other side of the adhesive sheet 33 is the adhesive force reduced or lost by heat treatment, and the adhesive sheet 33 and the support plate 31 can be peeled from the circuit pattern 3 on the insulating layer 7 together. For example, as the adhesive agent, a foaming agent or the like is included, and a foaming agent or the like that expands at a set temperature and the adhesive force on the bonding surface is reduced or lost. Other adhesives include capsules. There are heat treatment to expose the capsule to the bonding surface to form irregularities, and the bonding force on the bonding surface may be reduced or lost. In addition, an adhesive whose adhesive force changes at the melting point boundary can also be used.

In addition, when the insulating material 7 is heated and hardened, the adhesive force of the insulating material 7 to the circuit pattern 3 exceeds the adhesive force of the adhesive sheet 33 to the circuit pattern 3, and the adhesive sheet 33 is not limited to the thermal peeling sheet.

Then, as shown in the left diagram of FIG. 7, the intermediate transfer receiving portion 29 supported by the conveying jig not shown through the spring 35 is carried between the upper mold 11 and the lower mold 13 in the Y direction, for example. Move in here In the state, the gap between the adhesive sheet 33 and the template 25 becomes about half the thickness of the circuit pattern 3. This gap is set by keeping half of the thickness of the circuit pattern 3 inside the die to maintain the position accuracy, and it is set to adhere to the adhesive sheet 33 while maintaining the punching position of each circuit independent part 3a . Therefore, the gap can be set freely within the range where the pressing position can be maintained while being held.

Next, as shown in the right diagram of FIG. 7, the ejector 27 is raised by the drive of a hydraulic device or the like, and the ejector pin 27 a pushes up the circuit independent part 3 a, and then it is adhered to the adhesive sheet 33.

The state of transition to the middle of the adhesive sheet 33 becomes as shown in FIG. 8. In this intermediate transition state, each circuit independent part 3a is accurately maintained as the relative position of the circuit pattern 3 from the punching position.

(Heat transfer step)

The heating transfer step S3 of FIG. 9 is to perform the plurality of circuit independent parts 3a stamped out in the present embodiment, and indirectly transfer to the metal substrate 5 through the intermediate transfer step S2 pushed out from the stamping position together. The insulating layer 7 is used as the aforementioned circuit pattern 3.

As shown in FIG. 9, the intermediate transfer receiving portion 29 that has transferred the circuit pattern 3 to the adhesive sheet 33 is arranged on the metal substrate 5 by the movement of the transfer jig. The intermediate transfer receiving portion 29 descends at this position and the circuit pattern 3 and the intermediate transfer receiving portion 29 overlap on the insulating layer 7 of the metal substrate 5 together. By this overlapping, the circuit pattern 3 pairs the upper insulating layer 7.

Furthermore, the metal substrate 5A (FIG. 3) in the shape of a heat sink in FIG. 3 may be used instead of the metal substrate 5.

As shown in FIG. 10, the superposed components such as the metal substrate 5 and the support plate 31 are put into the heating furnace. In the heating furnace, the pressurizing device presses between the metal substrate 5 and the support plate 31 and heat treatment.

There may be cases where the height of the independent portion 3a of the circuit is relatively low at the central portion and so on. When pressurized, the insulating layer 7 will absorb a slight difference in height.

In addition, in the case of the metal substrate 5A in the shape of a fin, a member or the like that avoids the opening of the protrusion 5 a (FIG. 3) is used as the pressure plate.

In this heat and pressure treatment, since the circuit pattern 3 is pressed through the support plate 31 that is not easily deformed, even when the pressure is applied, the individual circuit parts 3a are not misaligned and the relative position at the time of pressing can be accurately maintained.

The heat treatment is, for example, 200° C.×60 minutes. By this heat treatment, the adhesive force of the adhesive sheet 33 to the circuit pattern 3 is reduced or lost, and the adhesive sheet 33 can be peeled from the circuit pattern 3 transferred to the insulating layer 7.

Therefore, if the intermediate transfer receiving portion 29 and the jig are raised together in the heating furnace or outside the heating furnace after the heat treatment, the circuit pattern 3 and the adhesive sheet 33 will be peeled off, and the circuit pattern 3 is completed on the metal substrate 5. Transfer of insulating layer 7.

The circuit pattern 3 transferred to the side of the metal substrate 5 in this way maintains the punching position of each circuit independent portion 3a, and the correct circuit pattern 3 can be obtained without misalignment as designed.

[Operation effect of the embodiment]

The method for manufacturing a metal base circuit board according to an embodiment of the present invention includes: a stamping step S1, a circuit pattern 3 having a plurality of circuit independent parts 3a is stamped out from the material plate W at the same time; an intermediate transfer step S2, maintaining the aforementioned stamping position, And transfer the plurality of circuit independent parts 3a to the intermediate transfer receiving part 29; and the heating transfer step S3, the plurality of circuit independent parts 3a stamped out are pushed out from the stamping position to make the middle The aforementioned intermediate transfer step S2 of the transfer is indirectly transferred from the punching position to the insulating layer 7 on the metal substrate 5 and used as the aforementioned circuit pattern 3.

That is, after the stamping step S1, the plurality of circuit independent portions 3a are intermediately transferred to the intermediate transfer receiving portion 29, and the intermediate transfer receiving portion 29 performs the heating transfer step S3 to transfer from the foregoing Indirect transfer of stamping position.

Therefore, the circuit independent portion 3a of the circuit pattern 3 stamped together at the stamping step S1 can be held at the stamping position and transferred to the intermediate transfer receiving portion 29 together, and can be held at the stamping position and transferred to the metal substrate together 5的 insulating层7.

Therefore, it is possible to obtain a correct circuit pattern 3 without misalignment, and it is possible to reliably suppress a current short circuit during use.

Since the circuit patterns 3 are stamped together, even a thick circuit pattern 3 with a thickness exceeding 0.5 mm in response to the demand for large current can increase the processing speed, and can also increase the cost and reduce the demand.

Using the support plate 31 provided with the adhesive sheet 33 on the surface as the intermediate transfer receiving portion 29 of the intermediate transfer step S2, and attaching the plurality of circuit independent portions 3a to the adhesive sheet 33 together to perform the intermediate transfer, Therefore, it is possible to perform the intermediate transfer with the stamping position maintained reliably.

In particular, in the pressurization heating process of the heat transfer step S3, the plurality of circuit independent portions 3a can be uniformly pressed through the support plate 31 that is not easily deformed.

Therefore, the plurality of circuit independent portions 3a are pressurized under almost the same pressure conditions, and displacement, relative positional misalignment, etc. of the plurality of circuit independent portions 3a can be reliably suppressed.

The adhesive sheet 33 is a thermal peeling sheet, and the adhesive force of the adhesive sheet 33 to the circuit pattern 3 is reduced or lost by heat treatment, and can be peeled from the circuit pattern 3 on the insulating layer 7.

Therefore, the circuit pattern 3 can be surely and easily transferred to the metal substrate 5 side.

Because the aforementioned adhesive sheet 33 is provided on the support plate 31 that is not easily deformed, the adhesive sheet 33 can be supported by the support plate 31 under the same conditions in a comprehensive manner.

Therefore, when the adhesive sheet 33 is peeled off from the circuit pattern 3, it is possible to obtain a uniform peeling effect on the plurality of circuit independent portions 3a, and the circuit pattern 3 can be surely transferred.

The circuit pattern 3 and the support plate 31 are copper products.

Therefore, the thermal expansion rate of the circuit pattern 3 and the support plate 31 is the same, and in the pressure heating process, the change in the relative positional relationship between the support plate 31, the adhesive sheet 33, and the circuit pattern 3 can be suppressed, and the circuit pattern 3 can be suppressed The displacement and positional misalignment are surely transferred.

In the case where the thickness of the aforementioned circuit pattern 3 exceeds 0.5 mm, even a large current demand can be fully satisfied.

[other]

The aforementioned intermediate transfer step S2 may also be omitted. For example, after the stamping step S1, the metal substrate 5 provided with the insulating layer 7 may be disposed between the upper mold 11 and the lower mold 13 by a transfer jig, and a plurality of circuit independent parts 3a may be pushed out together to make At this point, it is suspended on the insulating layer 7 in a semi-hardened state or the like. After the suspension, the insulating layer 7 is hardened by the same pressure and heat treatment as described above.

Therefore, the collective direct transfer of the circuit pattern 3 refers to a step of pushing out the circuit independent portion 3a together and passing it directly to the insulating layer 7 on the metal substrate 5 and suspending it.

In this case, it is possible to use an insulating adhesive film having an adhesive force capable of suspending a plurality of circuit independent portions 3a as the insulating layer 7.

In addition, the functions of the upper mold 11 and the lower mold 13 may be reversed, so that the plurality of circuit independent portions 3a after pressing stay on the upper mold 11 with the ejector of the upper mold 11 facing upward The metal substrate 5 carried in between the upper mold 11 and the lower mold 13 is operated, and a plurality of circuit independent portions 3a can be temporarily suspended on the insulating layer 7 of the metal substrate 5 while maintaining the pressing position. An electrostatic chuck or a suction chuck can be used as a means for stopping the plurality of circuit independent parts 3a after stamping on the upper die 11.

In the aforementioned intermediate transfer step S2, a UV peeling sheet may be used as the adhesive sheet 33. In this case, penetrating plastic products, glass products, or the like can be used as the support plate 31. When the adhesive sheet 33 is peeled from the circuit pattern 3, the support plate 31 is penetrated and ultraviolet rays are irradiated to the adhesive sheet 33 to reduce or lose the adhesive force of the adhesive sheet 33, whereby the circuit pattern 3 on the insulating layer 7 can be peeled off.

3‧‧‧ circuit pattern

3a‧‧‧Independent Division for Circuit

5‧‧‧Metal substrate

7‧‧‧Insulation

29‧‧‧Intermediate Transfer Accepting Department

31‧‧‧Support plate

33‧‧‧ Adhesive sheet

S3‧‧‧Heating transfer procedure

Claims (6)

A method of manufacturing a metal-based circuit board is characterized by having: A stamping step, stamping out a circuit pattern having a plurality of independent parts for circuits from the material plate; and In the transferring step, the plurality of stamped independent parts are transferred from the stamping position to the insulating layer on the metal substrate indirectly and used as the circuit pattern, or directly transferred to the insulating layer on the metal substrate Instead, it is used as the aforementioned circuit pattern. The method for manufacturing a metal-based circuit board as described in item 1 of the scope of the patent application, which includes an intermediate transfer step to maintain the stamping position and intermediately transfer the plurality of circuit independent parts to the intermediate transfer receiving part; After the stamping step, the plurality of circuit independent sections are transferred to the intermediate transfer receiving section, and the intermediate transfer receiving section performs the transfer in the transfer step to perform the indirect transfer. The method of manufacturing a metal-based circuit board as described in item 2 of the patent application range, wherein a support plate provided with an adhesive sheet on the surface is used as the intermediate transfer receiving portion of the intermediate transfer step, and the intermediate transfer is performed, and the plural The individual parts for each circuit are attached to the adhesive sheet together. The method for manufacturing a metal-based circuit board as described in item 3 of the patent application range, wherein the adhesive sheet is a thermal release sheet; By heat treatment, the adhesive force of the adhesive sheet to the circuit pattern is reduced or lost, whereby the adhesive sheet can be peeled from the circuit pattern on the insulating layer. The method for manufacturing a metal base circuit board as described in item 3 or item 4 of the patent application scope, wherein the circuit pattern and the support plate are made of the same material. The method for manufacturing a metal-based circuit board according to any one of the first to fourth patent application ranges, wherein the thickness of the circuit pattern exceeds 0.5 mm.

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