Thermoelectric separation plate and manufacturing method thereof

Abstract

The invention relates to a thermoelectric separation plate and a manufacturing method thereof, the thermoelectric separation plate comprises a circuit layer, an insulating layer and a copper-aluminum composite board, the circuit layer is provided with a plurality of first through holes, the insulating layer is provided with a plurality of second through holes in one-to-one correspondence with the first through holes, and the copper-aluminum composite board is provided with a plurality of second through holes in one-to-one correspondence with the second through holes. A plurality of protrusions in one-to-one correspondence with the second through holes are formed on the copper-aluminum composite board, the circuit layer, the insulating layer and the copper-aluminum composite board are sequentially laminated, and the protrusions sequentially penetrate through the corresponding second through holes and the first through holes; the copper-aluminum composite plate is adopted to replace an aluminum substrate to serve as a metal base layer of the thermoelectric separation plate, the copper-aluminum composite plate is of an integrated structure, the layering phenomenon between the aluminum substrate and a copper layer is avoided on the premise that the heat conduction performance is guaranteed, meanwhile, aluminum materials are reduced, and cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB, and in particular to a thermoelectric separation plate and a manufacturing method thereof. Background Art

[0002] The existing metal substrate consists of a three-layer structure, namely the circuit layer, the thermal insulation layer, and the metal base layer. The working principle of the metal substrate is as follows: the power device is mounted on the circuit layer, and the heat generated by the device is conducted to the metal base layer through the insulation layer, and then diffused from the metal base layer to the outside of the module to achieve heat dissipation. At present, the thermal conductivity of non-metallic insulation layers on the market is mostly 1-10W / MK, the thermal conductivity of copper is 398W / MK, and the thermal conductivity of aluminum is 237W / MK, so the insulation layer becomes the bottleneck layer of the entire heat dissipation path.

[0003] In order to solve the problem of limited heat dissipation efficiency of metal substrates, thermoelectric separation metal substrates have appeared on the market, such as the thermoelectric separation metal substrate proposed in the patent with application number CN201720586821.7, wherein the metal substrate comprises a metal base layer, an insulating layer and a circuit layer from bottom to top, the upper surface of the metal base layer has a boss, the lower surface of the metal base layer is provided with a protective tape and the remaining surfaces are provided with a copper plating layer, the insulating layer and the circuit layer are sequentially arranged on the copper plating layer on the upper surface of the metal base layer other than the boss, and the above-mentioned metal base layer is an aluminum substrate.

[0004] However, when copper is plated on an aluminum substrate, the bonding strength between the two is relatively weak and it is easy to delaminate, the quality is difficult to control, and the yield rate is high. Summary of the invention

[0005] In view of this, it is necessary to provide a thermoelectric separation plate and a method for manufacturing the same to solve the problem that when copper is plated on an aluminum substrate, the bonding force between the two is relatively weak and easy to delaminate, the quality is difficult to control, and the yield rate is high.

[0006] On the one hand, the present invention provides a thermoelectric separation plate, comprising a circuit layer, an insulating layer and a copper-aluminum composite plate, wherein the circuit layer is provided with a plurality of first through holes, the insulating layer is provided with a plurality of second through holes corresponding one-to-one to the first through holes, and the copper-aluminum composite plate is provided with a plurality of protrusions corresponding one-to-one to the second through holes, wherein the circuit layer, the insulating layer and the copper-aluminum composite plate are stacked in sequence, and the plurality of protrusions pass through the corresponding second through holes and the first through holes in sequence.

[0007] Furthermore, the volume ratio of copper to aluminum in the copper-aluminum composite plate is 3:7.

[0008] Furthermore, a protective tape is attached to the surface of the copper-aluminum composite plate away from the insulating layer, and a plurality of protrusions are formed on the surface of the copper-aluminum composite plate close to the insulating layer through etching.

[0009] Furthermore, the protrusion is a square block, and the first through hole and the second through hole are both square holes.

[0010] Furthermore, the circuit layer is a copper foil layer, the insulating layer is a PP layer, and the copper foil layer and the copper-aluminum composite board are pressed via the PP layer.

[0011] Furthermore, the circuit layer is a core board, one side of the core board close to the insulating layer is clad with copper, and the other side of the core board away from the insulating layer is not clad with copper, the insulating layer is a PP layer, and the core board and the copper-aluminum composite board are pressed together via the PP layer.

[0012] In another aspect, the present invention provides a method for manufacturing a thermoelectric separation plate, which is used to manufacture the thermoelectric separation plate as described above, comprising the following steps: Step S100, preparing a circuit layer, and drilling a plurality of first through holes on the circuit layer; Step S200, preparing an insulating layer, and drilling a plurality of second through holes on the insulating layer corresponding to the plurality of first through holes one by one; Step S300, preparing a copper-aluminum composite plate, attaching a protective tape to a surface of the copper-aluminum composite plate away from the insulating layer, and etching a surface of the copper-aluminum composite plate close to the insulating layer to form a plurality of protrusions; Step S400: The circuit layer, the insulating layer and the copper-aluminum composite plate are pressed together in sequence, and an outer layer circuit is prepared on the circuit layer.

[0013] In one embodiment, the preparation of the circuit layer in step S100 includes the following steps: Step S111, cutting the copper foil to a desired size; Step S112, drilling, drilling a plurality of first through holes on the copper foil; Step S113, copper foil gong groove, inner circle of the first through hole of the gong.

[0014] In another embodiment, the preparation of the circuit layer in step S100 includes the following steps: Step S121, cutting the core board to a required size; Step S122, drilling, drilling a plurality of second through holes on the core board; Step S123, outer dry film, affixing a dry film on the surface of the core board away from the insulating layer; Step S124, etching, etching the core board, forming an outer layer circuit on the surface of the core board away from the insulating layer, and etching away all the copper skin on the surface of the core board close to the insulating layer; Step S125: milling the inner circle of the core plate.

[0015] Furthermore, the preparation of the copper-aluminum composite plate in step S300 includes the following steps: Step S310, cutting the copper-aluminum composite plate to a desired size; Step S320, outer layer dry film, affixing dry film on the surface of the copper-aluminum composite plate close to the insulating layer and opening windows to expose non-protruding parts, and affixing surface protection tape on the side of the copper-aluminum composite plate away from the insulating layer; Step S330: etching, etching the copper-aluminum composite plate, etching away the copper layer at the openings of the copper-aluminum composite plate, thereby forming a plurality of protrusions.

[0016] Compared with the existing technology, a copper-aluminum composite plate is used instead of an aluminum substrate as the metal base layer of the thermoelectric separation plate. The copper-aluminum composite plate is an integrated structure. While ensuring thermal conductivity, it avoids stratification between the aluminum substrate and the copper layer. At the same time, it reduces the use of aluminum materials and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the overall structure of a thermoelectric separation plate provided in an embodiment of the present invention; Figure 2 A schematic diagram of a structure in which the circuit layer of a thermoelectric separation plate provided in an embodiment of the present invention is a copper foil; Figure 3 A schematic diagram of the structure of a core board in a thermoelectric separation board provided by an embodiment of the present invention; Figure 4 A schematic flow chart of a method for manufacturing a thermoelectric separation plate provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0019] On the one hand, if Figure 1 As shown, a thermoelectric separation plate provided by the present invention includes a circuit layer 100, an insulating layer 200 and a copper-aluminum composite plate 300, wherein a plurality of first through holes 110 are provided on the circuit layer 100, a plurality of second through holes 120 corresponding one-to-one to the first through holes 110 are provided on the insulating layer 200, and a plurality of protrusions 310 corresponding one-to-one to the second through holes 120 are formed on the copper-aluminum composite plate 300, wherein the circuit layer, the insulating layer 200 and the copper-aluminum composite plate 300 are sequentially stacked, and the plurality of protrusions 310 sequentially pass through the corresponding second through holes 120 and the first through holes 110.

[0020] Among them, the copper-aluminum composite plate 300 is used to replace the aluminum substrate as the metal base layer of the thermoelectric separation plate. The copper-aluminum composite plate 300 is an integrated structure. Under the premise of ensuring thermal conductivity, it avoids the stratification phenomenon between the aluminum substrate and the copper layer. At the same time, it reduces the use of aluminum materials and saves costs.

[0021] In this embodiment, the surface of the circuit layer 100 is used to mount power devices. The heat generated by the devices is conducted to the copper-aluminum composite board 300 through the insulating layer 200. In order to improve the heat dissipation effect of the entire metal substrate, a plurality of protrusions 310 extending to the circuit layer 100 are formed on the copper-aluminum composite board 300.

[0022] Embodiment 1, using the copper foil layer 120 as the circuit layer 100: like Figure 2 As shown, the circuit layer is a copper foil layer 120, the insulating layer 200 is a PP layer, and the copper foil layer 120 and the copper-aluminum composite board 300 are pressed together via the PP layer.

[0023] In Example 1, since a plurality of first through holes 110 need to be opened on the copper foil layer 120, burrs and copper scraps are easily formed on the inner wall of the first through holes 110. Since the copper foil is relatively thin, it is difficult to polish and clean it, which may cause a short circuit after lamination.

[0024] Based on the above problems, the present application solves the above problems through the solution in Example 2: like Figure 3 As shown, the circuit layer is a core board 130, one side of the core board 130 close to the insulating layer 200 is clad with copper, and the other side of the core board 130 away from the insulating layer 200 is not clad with copper. The insulating layer 200 is a PP layer, and the core board 130 and the copper-aluminum composite board 300 are pressed together via the PP layer.

[0025] Since both sides of the core board 130 are covered with copper, the copper on the surface of the core board 130 close to the insulating layer 200 can be etched away to facilitate the connection of the remaining insulating layers 200. The surface of the core board 130 away from the insulating layer 200 only needs to be made into the outer layer circuit. Since the core board 130 is relatively thick, the first through hole 110 can be polished and cleaned after drilling to avoid burrs and copper chips remaining.

[0026] It should be noted that although the solution described in Example 1 is not very effective, it can still achieve the inventive intent of this application.

[0027] The insulating layer 200 in this embodiment is a PP layer, which is used to bond the circuit layer 100 and the copper-aluminum composite board 300 .

[0028] The copper-aluminum composite plate 300 in this embodiment replaces the aluminum substrate as the metal base layer of the thermoelectric separation plate. The copper-aluminum composite plate 300 is an integrated structure, which avoids the delamination between the aluminum substrate and the copper layer while ensuring the thermal conductivity.

[0029] The copper-aluminum volume ratio of the copper-aluminum composite plate 300 is 3 to 7. The thermal conductivity of copper is about 400 W / m·K, while the thermal conductivity of aluminum is about 237 W / m·K, which can ensure that the copper-aluminum composite plate 300 has good thermal conductivity. It is understandable that the copper-aluminum volume ratio of the copper-aluminum composite plate 300 can also be set to other parameters, which is not limited in this embodiment.

[0030] It should be noted that the copper-aluminum composite plate 300 in this embodiment is formed by welding copper plates and aluminum plates together by cold rolling, hot rolling, explosive composite method, explosive rolling method, etc. to form an inseparable material, which replaces the copper plating method on the aluminum substrate and effectively avoids copper-aluminum stratification.

[0031] After the lamination is completed, in order to prevent the acid and alkali in the subsequent process from reacting with the copper-aluminum composite plate 300, in this embodiment, a protective tape is attached to the surface of the copper-aluminum composite plate 300 away from the insulating layer 200. At the same time, a plurality of protrusions 310 are formed by etching on the surface of the copper-aluminum composite plate 300 close to the insulating layer 200.

[0032] The protrusion 310 in this embodiment is a square block, and the first through hole 110 and the second through hole 120 are both square holes. It is understandable that the protrusion 310 can also adopt a pancake-shaped structure, and the first through hole 110 and the second through hole 120 are arranged corresponding to the shape of the protrusion 310.

[0033] On the other hand, Figure 4 As shown, the present invention provides a method for manufacturing a thermoelectric separation plate, which is used to manufacture the thermoelectric separation plate as described above, comprising the following steps: Step S100, preparing a circuit layer, and drilling a plurality of first through holes on the circuit layer; wherein the size of the first through holes is 0.25 mm larger than the protrusion; Step S200, preparing an insulating layer, and providing a plurality of second through holes corresponding to the plurality of first through holes on the insulating layer; the inner diameter of the second through holes should be controlled to be 0.4 mm larger than the inner diameter of the first through holes, wherein a plurality of positioning holes and rivet holes used in the pressing process need to be drilled on the insulating layer; Step S300, preparing a copper-aluminum composite plate, attaching a protective tape to a surface of the copper-aluminum composite plate away from the insulating layer, and etching a surface of the copper-aluminum composite plate close to the insulating layer to form a plurality of protrusions; Step S400: The circuit layer, the insulating layer and the copper-aluminum composite plate are pressed together in sequence, and an outer layer circuit is prepared on the circuit layer.

[0034] In one embodiment, the preparation of the circuit layer in step S100 includes the following steps: Step S111 , cutting the copper foil to a desired size; wherein the thickness of the copper foil is 3 oz.

[0035] Step S112, drilling, drilling a plurality of first through holes on the copper foil; Step S113, copper foil gong groove, inner circle of the first through hole of the gong.

[0036] In another embodiment, the preparation of the circuit layer in step S100 includes the following steps: Step S121, cutting the core board to a required size; Step S122, drilling, drilling a plurality of second through holes on the core board; Step S123: outer dry film, affixing a dry film on the surface of the core board away from the insulating layer. Step S124, etching, etching the core board, forming an outer layer circuit on the surface of the core board away from the insulating layer, and etching away all the copper skin on the surface of the core board close to the insulating layer; Step S125: milling the inner circle of the core plate.

[0037] Furthermore, the preparation of the copper-aluminum composite plate in step S300 includes the following steps: Step S310, cutting the copper-aluminum composite plate to a desired size; wherein the copper-aluminum ratio of the copper-aluminum composite plate is 15 / 85%, and the plate thickness is 1.6 mm. After the material is received, an automatic shearing machine can be used to cut the material; Step S320, outer layer dry film, affixing dry film on the surface of the copper-aluminum composite plate close to the insulating layer and opening windows to expose non-protruding parts, and affixing surface protection tape on the side of the copper-aluminum composite plate away from the insulating layer; Step S330, etching, etching the copper-aluminum composite plate, etching away the copper layer at the opening of the copper-aluminum composite plate, thereby forming a plurality of protrusions. The copper-aluminum composite plate is etched away to a thickness of 170 um, and the corresponding protrusion height is 170 um.

[0038] In step S400, the specific process is as follows: Step S410, lamination, laminating the circuit layer, the insulating layer and the copper-aluminum composite plate in sequence, the pressed copper thickness is 105um, and the thickness of the thermoelectric separation plate after lamination is 1.6+ / -0.1mm, wherein the aluminum-copper composite plate is mixed with 3oz copper foil (the protrusions etched on the aluminum-copper substrate are embedded with the first through holes on the copper foil); Step S420, cutting and grinding the plate, cutting and grinding the thermoelectric separation plate to the required size, and grinding the plate. It should be noted that in the resin grinding line, the PP overflow glue and PP residual glue on the plate surface need to be ground, and the grinding should be checked to ensure that it is clean. Check whether there is residual glue on the surface of the copper block, which must be manually cleaned. After grinding, the copper thickness around the copper block needs to be measured to confirm whether it meets the requirements; Step S430, outer layer dry film, laying dry film on the circuit layer of the hot spot separation board; Step S440, forming an outer layer circuit through developing and exposure; Step S450, etching, etching away the copper layer where the dry film is not laid, and removing the dry film; Step S460, outer layer AOI; Step S470, solder resist, for thick copper plate, solder resist needs to be done twice; Step S480, character; Step S490, nickel-gold deposition; Step S410, drilling; Step S411: testing; Step S412, BV-CUT; Step S413, edge milling; Step S414, BFQC; Step S415, BFQA; Step S416: packaging.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A thermoelectric separation plate, characterized in that: include: A circuit layer, on which a plurality of first through holes are formed; an insulating layer, on which a plurality of second through holes corresponding one to one with the first through holes are formed; A copper-aluminum composite plate, on which a plurality of protrusions corresponding to the second through holes are formed; The circuit layer, the insulating layer and the copper-aluminum composite plate are stacked in sequence, and the plurality of protrusions pass through the corresponding second through holes and the first through holes in sequence.

2. The thermoelectric separation plate according to claim 1, characterized in that: The volume ratio of copper to aluminum in the copper-aluminum composite plate is 3:

7.

3. The thermoelectric separation plate according to claim 1, characterized in that: A protective tape is attached to the surface of the copper-aluminum composite plate away from the insulating layer, and a plurality of protrusions are formed on the surface of the copper-aluminum composite plate close to the insulating layer through etching.

4. The thermoelectric separation plate according to claim 1, characterized in that: The protrusion is a square block, and the first through hole and the second through hole are both square holes.

5. The thermoelectric separation plate according to claim 1, characterized in that: The circuit layer is a copper foil layer, the insulating layer is a PP layer, and the copper foil layer and the copper-aluminum composite board are formed by pressing through the PP layer.

6. The thermoelectric separation plate according to claim 1, characterized in that: The circuit layer is a core board, one side of the core board close to the insulating layer is clad with copper, and the other side of the core board away from the insulating layer is not clad with copper, the insulating layer is a PP layer, and the core board and the copper-aluminum composite board are pressed together via the PP layer.

7. A method for manufacturing a thermoelectric separation plate, used for manufacturing the thermoelectric separation plate as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Prepare a circuit layer, and drill a plurality of first through holes in the circuit layer; An insulating layer is prepared, and a plurality of second through holes corresponding to the plurality of first through holes are opened on the insulating layer. A copper-aluminum composite plate is prepared, a protective tape is attached to a surface of the copper-aluminum composite plate away from the insulating layer, and a surface of the copper-aluminum composite plate close to the insulating layer is etched to form a plurality of protrusions; The circuit layer, the insulating layer and the copper-aluminum composite plate are pressed together in sequence, and an outer layer circuit is prepared on the circuit layer.

8. The method for manufacturing a thermoelectric separation plate according to claim 7, characterized in that: The preparation of the circuit layer comprises the following steps: Cut the copper foil to the required size; Drilling: drilling a plurality of first through holes on the copper foil; Copper foil gong groove, the inner circle of the first through hole of the gong.

9. The method for manufacturing a thermoelectric separation plate according to claim 7, characterized in that: The preparation of the circuit layer comprises the following steps: Cut the core board to the required size; Drilling, drilling a plurality of second through holes on the core board; The outer dry film is applied to the surface of the core board away from the insulation layer. Etching: etching the core board, forming an outer layer circuit on the surface of the core board away from the insulating layer, and etching away all the copper skin on the surface of the core board close to the insulating layer; Milling: Mill the inner circle of the core plate.

10. The method for manufacturing a thermoelectric separation plate according to claim 7, characterized in that: The preparation of the copper-aluminum composite plate comprises the following steps: Cut the copper-aluminum composite panels to the required size; The outer layer of dry film is attached to the surface of the copper-aluminum composite plate close to the insulating layer and a window is opened to expose the non-raised part, and the surface protection tape is attached to the side of the copper-aluminum composite plate away from the insulating layer; Etching is performed on the copper-aluminum composite plate, and the copper layer at the window opening of the copper-aluminum composite plate is etched away, thereby forming a plurality of protrusions.

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