Metal-based phase change heat transfer PCB and manufacturing process therefor

Abstract

The present invention provides a metal-based phase change heat transfer PCB and a manufacturing process therefor. The manufacturing process comprises: preparing a metal-based phase change device; using a spray coating process and / or a knife coating process to process a polymer layer on the surface of the phase change device, and using an electroplating process to process on the surface of the polymer layer an electroplated copper layer used for manufacturing a printed circuit; covering and sticking on the surface of the electroplated copper layer a blue mask used for preventing chemical etching, and processing on the opposite surface of the electroplated copper layer a polymer layer used for preventing chemical etching; drawing a circuit on the blue mask, using an exposure process and a developing process to process the circuit on the surface of the electroplated copper layer, and reserving the frame of the electroplated copper layer and the blue mask covering the circuit; using a single-side spray chemical etching process to process the surface of the electroplated copper layer, and etching the area of the surface of the electroplated copper layer not covered by the blue mask; and performing cleaning to remove the blue mask covering the electroplated copper layer and remove the polymer layer on the opposite surface of the electroplated copper layer, and coating the electroplated copper layer located on the circuit with a solder mask used for insulation to complete manufacturing of the PCB.

Description

A metal-based phase-change heat transfer PCB board and its manufacturing process Technical Field

[0001] The present invention relates to the technical field of circuit board heat dissipation, and in particular to a metal-based phase-change heat transfer PCB board and a manufacturing process thereof. Background Art

[0002] Existing circuit boards are divided into polymer-based circuit boards and metal-based circuit boards. Metal-based circuit boards have a much higher thermal conductivity than polymer-based substrates. Therefore, metal-based circuit boards are mainly used in scenarios where high-power devices are soldered on substrates such as power semiconductors.

[0003] However, as power usage demands increase, the power of power devices is further increased. Traditional metal-based circuit boards alone can no longer meet the heat dissipation needs of power devices. The lack of high heat dissipation performance of circuit board substrates will seriously affect the power increase of power devices. It is necessary to improve the heat transfer efficiency of circuit board substrates to improve the performance of power devices.

[0004] Therefore, how to improve the thermal conductivity of the circuit board substrate to increase the power consumption of power devices is an urgent problem that needs to be solved.

[0005] Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the present invention proposes a metal-based phase change heat transfer PCB board and its manufacturing process, which can improve the problem of insufficient heat transfer performance of the circuit board substrate.

[0007] A first aspect of the disclosed embodiments provides a process for manufacturing a metal-based phase-change heat transfer PCB board, comprising the following steps:

[0008] S1: Preparation of metal-based phase change devices;

[0009] S2: processing a polymer layer on the surface of the phase change device by a spraying process and / or a scraping process, and processing an electroplated copper layer for manufacturing a printed circuit on the surface of the polymer layer by an electroplating process;

[0010] S3: covering the electroplated copper layer with a blue film for preventing chemical etching, and processing a polymer layer for preventing chemical etching on the opposite side of the electroplated copper layer;

[0011] S4: drawing a circuit on the blue film, processing the circuit on the surface of the electroplated copper layer using an exposure process and a development process, and retaining the frame of the electroplated copper layer and the blue film covering the circuit;

[0012] S5: processing the surface of the electroplated copper layer using a single-sided spray chemical etching process to etch areas of the surface of the electroplated copper layer that are not covered by the blue film;

[0013] S6: The blue film covering the electroplated copper layer is removed by cleaning, and the polymer layer on the opposite side of the electroplated copper layer is removed, and green oil for insulation is applied on the electroplated copper layer located on the circuit to complete the manufacture of the PCB board.

[0014] In one embodiment of the present disclosure, the phase change device is an anti-expansion heat conductive phase change heat transfer device, and its preparation process includes the following steps:

[0015] S11: processing the upper shell plate and the lower shell plate by etching or stamping, respectively processing grooves forming an upper inner cavity and a lower inner cavity on the surfaces of the upper shell plate and the lower shell plate, then forming support columns in the grooves, and retaining welding edges and injection sections around the support columns;

[0016] S12: processing the liquid wick by a stamping process, and retaining through holes corresponding to the shell plate support columns on the liquid wick;

[0017] S13: placing the liquid wick in the inner cavity of the matching upper shell plate or lower shell plate, pressing the liquid wick with a graphite mold and then performing a high-temperature sintering process to connect the liquid wick and the matching shell plate, wherein the high-temperature sintering temperature is not less than 650° C.;

[0018] S14: Processing the injection section into an injection groove through a stamping process, splicing the upper shell plate and the lower shell plate, placing them in a graphite mold, and connecting them through a welding process to form a phase change device;

[0019] S15: pouring the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then vacuuming the inner cavity of the phase change device and completing the manufacturing of the phase change device through a sealing welding process.

[0020] In one embodiment of the present disclosure, the thickness of the polymer layer is processed according to insulation requirements, and the thickness ranges from 0.01 mm to 0.3 mm.

[0021] In one embodiment of the present disclosure, the thickness of the electroplated copper layer is processed according to the working power required by the PCB board, and the thickness ranges from 0.01 mm to 0.5 mm.

[0022] In one embodiment of the present disclosure, the polymer layer is a material for preventing chemical etching, and the material includes PTE, PP and PI.

[0023] In one embodiment of the present disclosure, step S2 includes the following steps:

[0024] S21: applying a high-temperature heat-resistant adhesive layer on the surface of the phase change device, processing a copper-polymer layer with a copper-clad film layer, and laminating the polymer material surface of the copper-polymer layer to the high-temperature heat-resistant adhesive layer;

[0025] S22: rolling and / or scraping the surface of the copper-polymer layer to ensure that the high-temperature heat-resistant adhesive layer is in close contact with the polymer material surface of the copper-polymer layer.

[0026] In one embodiment of the present disclosure, the copper clad film layer includes PET copper clad film, PP copper clad film and PI film, and the opposite surface of the copper clad film layer is a polymer-copper composite material.

[0027] In one embodiment of the present disclosure, step S3 includes the following steps:

[0028] S31: Selecting a blue film with an area larger than that of the electroplated copper layer to cover the surface of the electroplated copper layer, and processing the edge of the blue film extending from the edge of the electroplated copper layer to form a slope for the corrosive liquid to slide down along the edge.

[0029] According to a second aspect of the embodiments of the present disclosure, there is provided a metal-based phase change heat transfer PCB board, comprising:

[0030] A phase change device, a polymer layer and an electroplated copper layer, wherein the polymer layer is arranged on the surface of the phase change device, the electroplated copper layer is arranged on the surface of the polymer layer and the phase change device and the electroplated copper layer are insulated and isolated by the polymer layer, and after the electroplated copper layer is etched, a copper circuit and a copper frame are retained on the surface of the polymer layer.

[0031] In one embodiment of the present disclosure, a high-temperature heat-resistant adhesive layer is further provided between the phase change device and the polymer layer.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] The present invention insulates a phase change device with anti-expansion and high thermal conductivity from a PCB board through a polymer layer of a polymer material. At the same time, the polymer layer can play a role in efficient heat transfer, thereby improving the heat dissipation performance of the circuit board through the phase change device. In addition, the metal-based phase change device replaces the copper or aluminum substrate without adversely affecting the circuit board, thereby ensuring that the circuit board can operate at a higher power without worrying about heat dissipation problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0035] FIG1 is a schematic diagram of a process for manufacturing a metal-based phase-change heat transfer PCB board according to the present invention;

[0036] FIG2 is a schematic structural diagram of a metal-based phase-change heat transfer PCB board according to the present invention;

[0037] FIG3 is a schematic diagram of FIG2 from another perspective;

[0038] FIG4 is a schematic diagram of the structure of a blue film covered in a metal-based phase change heat transfer PCB board manufacturing process according to the present invention;

[0039] FIG5 is a schematic diagram of FIG4 from another perspective;

[0040] FIG6 is a schematic diagram of a process for manufacturing a metal-based phase change heat transfer PCB board according to a second embodiment of the present invention;

[0041] FIG7 is a schematic diagram of a process for manufacturing a metal-based phase change heat transfer PCB board according to a third embodiment of the present invention;

[0042] FIG8 is a schematic structural diagram of a metal-based phase change heat transfer PCB board according to a fourth embodiment of the present invention;

[0043] FIG9 is a schematic diagram of FIG8 from another perspective.

[0044] Figure identification: 1-phase change device, 2-polymer layer, 3-electroplated copper layer, 4-blue film, 5-copper frame, 6-copper circuit, 7-high temperature and heat-resistant adhesive layer. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0048] Example 1

[0049] 1 to 5 , a metal-based phase change heat transfer PCB manufacturing process includes the following steps:

[0050] S1: Preparation of metal-based phase change devices;

[0051] It should be noted that metal-based phase change devices can be made of materials with high thermal conductivity such as copper-based or aluminum-based materials. At the same time, phase change devices need to have anti-expansion properties to prevent the internal saturated vapor pressure of the phase change device from being greater than the external atmospheric pressure due to excessively high welding temperature during the soldering process, causing the phase change device to expand and affect the heat dissipation efficiency of the phase change device for the PCB board.

[0052] S2: processing a polymer layer on the surface of the phase change device by a spraying process and / or a scraping process, and processing an electroplated copper layer for manufacturing a printed circuit on the surface of the polymer layer by an electroplating process;

[0053] In one embodiment of the present disclosure, the polymer layer is a material for preventing chemical etching, and the material includes PTE, PP and PI.

[0054] In one embodiment of the present disclosure, the thickness of the polymer layer is processed according to insulation requirements, and the thickness ranges from 0.01 mm to 0.3 mm.

[0055] In one embodiment of the present disclosure, the thickness of the electroplated copper layer is processed according to the working power required by the PCB board, and the thickness ranges from 0.01 mm to 0.5 mm.

[0056] S3: covering the electroplated copper layer with a blue film for preventing chemical etching, and processing a polymer layer for preventing chemical etching on the opposite side of the electroplated copper layer;

[0057] In one embodiment of the present disclosure, step S3 includes the following steps:

[0058] S31: Selecting a blue film with an area larger than that of the electroplated copper layer to cover the surface of the electroplated copper layer, and processing the edge of the blue film extending from the edge of the electroplated copper layer to form a slope for the corrosive liquid to slide down along the edge.

[0059] It should be noted that sticking a blue film with an area larger than the copper substrate on the copper-plated surface of the copper-plated substrate can prevent the corrosive liquid from contacting the side of the phase change device during the subsequent chemical etching process, causing corrosion of the phase change device and affecting the heat dissipation of the phase change device.

[0060] It should be noted that polymer tape, including but not limited to PET, PP and PI, is applied to the non-copper surface of the copper-plated substrate to prevent the etching solution from contacting the bottom surface of the device during etching, which may cause device failure.

[0061] S4: drawing a circuit on the blue film, processing the circuit on the surface of the electroplated copper layer using an exposure process and a development process, and retaining the frame of the electroplated copper layer and the blue film covering the circuit;

[0062] S5: processing the surface of the electroplated copper layer using a single-sided spray chemical etching process to etch areas of the surface of the electroplated copper layer that are not covered by the blue film;

[0063] It should be noted that single-sided spray chemical etching is used to remove the areas of the copper-plated surface not protected by the blue film. That is, the etching solution is only sprayed on the side of the substrate with the blue film. The solution sprayed on the substrate will flow along the edge of the blue film and will not come into contact with the phase change device.

[0064] S6: The blue film covering the electroplated copper layer is removed by cleaning, and the polymer layer on the opposite side of the electroplated copper layer is removed, and green oil for insulation is applied on the electroplated copper layer located on the circuit to complete the manufacture of the PCB board.

[0065] It should be noted that short circuits on PCBs can be further avoided by applying green oil for insulation on the copper clad substrate with circuits.

[0066] In one embodiment of the present disclosure, the phase change device is an anti-expansion heat conductive phase change heat transfer device, and its preparation process includes the following steps:

[0067] S11: processing the upper shell plate and the lower shell plate by etching or stamping, respectively processing grooves forming an upper inner cavity and a lower inner cavity on the surfaces of the upper shell plate and the lower shell plate, then forming support columns in the grooves, and retaining welding edges and injection sections around the support columns;

[0068] S12: processing the liquid wick by a stamping process, and retaining through holes corresponding to the shell plate support columns on the liquid wick;

[0069] S13: placing the liquid wick in the inner cavity of the matching upper shell plate or lower shell plate, pressing the liquid wick with a graphite mold and then performing a high-temperature sintering process to connect the liquid wick and the matching shell plate, wherein the high-temperature sintering temperature is not less than 650° C.;

[0070] S14: Processing the injection section into an injection groove through a stamping process, splicing the upper shell plate and the lower shell plate, placing them in a graphite mold, and connecting them through a welding process to form a phase change device;

[0071] S15: pouring the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then vacuuming the inner cavity of the phase change device and completing the manufacturing of the phase change device through a sealing welding process.

[0072] It should be noted that the above-mentioned phase change device is one of the phase change devices that can achieve anti-expansion and high thermal conductivity. In this embodiment, any phase change device that can achieve anti-expansion and high thermal conductivity can be used to manufacture metal-based phase change heat transfer PCB boards.

[0073] The present invention insulates a phase change device with anti-expansion and high thermal conductivity from a PCB board through a polymer layer of a polymer material. At the same time, the polymer layer can play a role in efficient heat transfer, thereby improving the heat dissipation performance of the circuit board through the phase change device. In addition, the metal-based phase change device replaces the copper or aluminum substrate without adversely affecting the circuit board, thereby ensuring that the circuit board can operate at a higher power without worrying about heat dissipation problems.

[0074] Example 2

[0075] As shown in FIG6 , the embodiment of the present invention differs from the first embodiment in that: in step S2 of the manufacturing process for a metal-based phase change heat transfer PCB board, the following steps are adopted:

[0076] S21: applying a high-temperature heat-resistant adhesive layer on the surface of the phase change device, processing a copper-polymer layer with a copper-clad film layer, and laminating the polymer material surface of the copper-polymer layer to the high-temperature heat-resistant adhesive layer;

[0077] S22: rolling and / or scraping the surface of the copper-polymer layer to ensure that the high-temperature heat-resistant adhesive layer is in close contact with the polymer material surface of the copper-polymer layer.

[0078] In one embodiment of the present disclosure, the copper clad film layer includes PET copper clad film, PP copper clad film and PI film, and the opposite surface of the copper clad film layer is a polymer-copper composite material.

[0079] It should be noted that by applying a layer of high-temperature heat-resistant adhesive to the phase-change device, the polymer material side of the copper film is brought into contact with the heat-resistant adhesive. The copper film is completely applied to the surface of the phase-change device by rolling or scraping, and the excess high-temperature heat-resistant adhesive between the copper film and the phase-change device is squeezed out. Copper film types include PET copper film, PP copper film, and PI film. These polymer-copper composite materials have a polymer material on one side and copper on the other side. They can efficiently complete heat transfer and further improve the heat dissipation performance of the circuit board.

[0080] Example 3

[0081] As shown in FIG7 , the embodiment of the present invention differs from the second embodiment in that, in step S2 of the manufacturing process for a metal-based phase change heat transfer PCB board, the following steps are adopted:

[0082] S21: Processing the copper-polymer layer with the copper film layer, using a hot pressing process to press the polymer layer covered with the copper film layer and the phase change device until the hot pressing process temperature drops to 95° C. and then removing the pressure head to complete the pressing process;

[0083] In one embodiment of the present disclosure, the copper-clad film layer includes PET copper-clad film, PP copper-clad film and PI film, and the opposite surface of the copper-clad film layer is a polymer-copper composite material.

[0084] It should be noted that the phase change device and the polymer layer covering the copper film layer are processed through a hot pressing process, which replaces the bonding installation method of high-temperature heat-resistant adhesive. The polymer layer covered with the electroplated copper layer can also be installed tightly on the phase change device. The hot pressing process can ensure that the polymer layer is pressed tightly against the phase change device under high temperature to ensure the strength and stability of the overall structure. It can also enable the phase change device to efficiently complete heat conversion and further improve the heat dissipation performance of the circuit board.

[0085] Example 4

[0086] 2, 3, 8 and 9, an embodiment of the present invention discloses a metal-based phase change heat transfer PCB board, comprising:

[0087] A phase change device 1, a polymer layer 2 and an electroplated copper layer 3, wherein the polymer layer 2 is arranged on the surface of the phase change device 1, the electroplated copper 3 layer is arranged on the surface of the polymer layer 2 and the phase change device 1 and the electroplated copper layer 3 are insulated and isolated by the polymer layer 2, and after the electroplated copper layer 3 is etched, a copper circuit 5 and a copper frame 6 are retained on the surface of the polymer layer 2.

[0088] In one embodiment of the present disclosure, a high-temperature heat-resistant adhesive layer 7 is further provided between the phase change device 1 and the polymer layer 2 .

[0089] In one embodiment of the present disclosure, the thickness of the polymer layer 2 is processed according to insulation requirements, and its thickness ranges from 0.01 mm to 0.3 mm.

[0090] In one embodiment of the present disclosure, the thickness of the electroplated copper layer 3 is processed according to the working power required by the PCB board, and the thickness ranges from 0.01 mm to 0.5 mm.

[0091] In one embodiment of the present disclosure, the polymer layer 2 is a material for preventing chemical etching, and the material includes PTE, PP and PI.

[0092] The present invention insulates a phase change device with anti-expansion and high thermal conductivity from a PCB board through a polymer layer of a polymer material. At the same time, the polymer layer can play a role in efficient heat transfer, thereby improving the heat dissipation performance of the circuit board through the phase change device. In addition, the metal-based phase change device replaces the copper or aluminum substrate without adversely affecting the circuit board, thereby ensuring that the circuit board can operate at a higher power without worrying about heat dissipation problems.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A manufacturing process for a metal-based phase change heat transfer PCB board, characterized in that, The following steps are involved: S1: Preparation of metal-based phase change devices; S2: using a spraying process and / or a scraping process to process a polymer layer on the surface of the phase change device, and using an electroplating process to process an electroplated copper layer for manufacturing a printed circuit on the surface of the polymer layer; S3: covering and pasting a blue film for preventing chemical etching on the electroplated copper layer, and processing a polymer layer for preventing chemical etching on the opposite side of the electroplated copper layer; S4: drawing a circuit on the blue film, processing the circuit on the surface of the electroplated copper layer by using an exposure process and a development process, and retaining the frame of the electroplated copper layer and the blue film covering the circuit; S5: processing the surface of the electroplated copper layer by a single-sided spray chemical etching process to etch the area of ​​the surface of the electroplated copper layer that is not covered by the blue film; S6: The blue film covering the electroplated copper layer is removed by cleaning, and the polymer layer on the opposite side of the electroplated copper layer is removed, and green oil for insulation is coated on the electroplated copper layer located on the circuit to complete the manufacture of the PCB board.

2. The manufacturing process of the metal-based phase change heat transfer PCB board according to claim 1, characterized in that, The phase change device is an anti-expansion heat-conducting phase change heat transfer device, and its preparation process includes the following steps: S11: processing the upper shell plate and the lower shell plate by etching or stamping, processing grooves forming the upper inner cavity and the lower inner cavity on the surfaces of the upper shell plate and the lower shell plate respectively, and then forming support columns in the grooves, and retaining welding edges and injection sections around the support columns; S12: processing the liquid absorbing core by a stamping process, and retaining through holes corresponding to the shell plate supporting columns on the liquid absorbing core; S13: placing the liquid wick in the inner cavity of the matching upper shell plate or lower shell plate, pressing the liquid wick with a graphite mold and then performing high-temperature sintering to connect the liquid wick and the matching shell plate, wherein the high-temperature sintering temperature is not less than 650° C.; S14: Processing the injection section into an injection groove through a stamping process, splicing the upper shell plate and the lower shell plate, placing them in a graphite mold, and connecting them through a welding process to form a phase change device; S15: pouring the working fluid into the upper inner cavity and the lower inner cavity formed by the upper shell plate and the lower shell plate through the liquid injection tank, and then vacuumizing the inner cavity of the phase change device and completing the manufacturing of the phase change device through a sealing welding process.

3. The manufacturing process of the metal-based phase change heat transfer PCB board according to claim 1, wherein The thickness of the polymer layer is processed according to insulation requirements, and its thickness ranges from 0.01mm to 0.3mm.

4. The manufacturing process of the metal-based phase change heat transfer PCB board according to claim 1, characterized in that, The thickness of the electroplated copper layer is processed according to the working power required by the PCB board, and its thickness ranges from 0.01mm to 0.5mm.

5. The manufacturing process of the metal-based phase change heat transfer PCB board according to claim 1, characterized in that, The polymer layer is a material used to prevent chemical etching, and the material includes PTE, PP and PI.

6. The manufacturing process of the metal-based phase change heat transfer PCB board according to claim 1, characterized in that, The step S2 includes the following steps: S21: coating a high-temperature heat-resistant adhesive layer on the surface of the phase change device, processing a copper-polymer layer with a copper-clad film layer, and attaching the polymer material surface of the copper-polymer layer to the high-temperature heat-resistant adhesive layer; S22: rolling and / or scraping on the surface of the copper-polymer layer to make the high-temperature heat-resistant adhesive layer closely fit with the polymer material surface of the copper-polymer layer.

7. The metal-based phase change heat transfer PCB board according to claim 6, wherein, The types of copper-clad films of the copper-clad film layer include PET copper-clad film, PP copper-clad film and PI film, and the opposite side of the copper-clad film layer is a polymer-copper composite material.

8. The metal-based phase change heat transfer PCB board according to claim 1, wherein The step S3 includes the following steps: S31: Select a blue film with an area larger than that of the electroplated copper layer and cover it on the surface of the electroplated copper layer, and process the edge of the blue film extending out of the edge of the electroplated copper layer to form an inclined surface for the etching solution to slide down along the edge.

9. A metal-based phase change heat transfer PCB board, characterized in that, Including: A phase change device, a polymer layer, and an electroplated copper layer. The polymer layer is disposed on the surface of the phase change device. The electroplated copper layer is disposed on the surface of the polymer layer, and the phase change device and the electroplated copper layer are insulated and isolated through the polymer layer. After the electroplated copper layer is etched, a copper circuit and a copper border are reserved on the surface of the polymer layer.

10. The metal matrix phase change heat transfer PCB board according to claim 9, characterized in that, A high-temperature heat-resistant adhesive layer is further disposed between the phase change device and the polymer layer.

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