High-thermal-conductivity low-loss multi-layer PCB for new energy automobile and preparation process thereof

Abstract

The invention belongs to the technical field of PCB manufacturing, and particularly relates to a high-thermal-conductivity low-loss multilayer PCB for a new energy automobile and a preparation process thereof, and the multilayer PCB comprises a PCB main body and a heat conduction element embedded in the PCB main body. The special sandwich insulating layer is adopted to replace a prepreg of a conventional PCB, the first electroless copper is formed on the side portion of the PCB body, the first electroless copper on the side portion and the heat conduction film in the sandwich insulating layer form the Faraday cage, the circuit except the first layer and the last layer in the PCB body is wrapped in the shielding space, a high-frequency changing magnetic field can be shielded, and the shielding performance of the PCB body is improved. The problem of high PCB loss caused by a magnetic leakage magnetic field of a motor of an electric car is solved. And secondly, a blind hole heat conduction element can be matched with a plurality of heat conduction films for heat dissipation, and only a through hole heat conduction element is not used any more, so that the wiring space of the multi-layer PCB can be saved to the greatest extent, the size of the PCB is further reduced, and the problem that the size of the existing high-heat-conduction multi-layer PCB is too large can be solved.

Description

Technical Field

[0001] The present application belongs to the field of PCB manufacturing technology, and in particular relates to a high-thermal-conductivity, low-loss multi-layer PCB for new energy vehicles and its preparation process. Background Art

[0002] The new energy vehicle industry has developed rapidly in recent years, and the market share of electric vehicles has repeatedly set new highs. As the carrier of electronic components of new energy vehicles, the quality of PCB can to a certain extent reflect the quality of the electronic devices of new energy vehicles.

[0003] Because cars generate heat and are easily affected by ambient temperature, PCBs used in new energy vehicles must have better thermal conductivity than ordinary PCBs. However, when existing high-thermal-conductivity PCBs are used directly in new energy vehicles, there are problems caused by not considering the characteristics and scenarios of new energy vehicles. These problems include: not considering the possibility of magnetic leakage from the electric vehicle's motor. The high-frequency changing magnetic field leaked by the motor will generate induced current in the PCB circuit, which will increase the PCB circuit loss; not considering the compact interior space of the car. Existing high-thermal-conductivity PCBs usually use through-holes for heat conduction. When the PCB is a multi-layer PCB, the opening of through-holes for heat conduction will significantly increase the volume of the multi-layer PCB. Summary of the Invention

[0004] The embodiments of the present application provide a high-thermal-conductivity, low-loss multi-layer PCB for new energy vehicles and its preparation process, which can solve the problem of high PCB loss caused by the high-frequency changing magnetic field generated by the electric vehicle's motor and the excessive size of existing high-thermal-conductivity multi-layer PCBs.

[0005] In a first aspect, the embodiments of the present application provide a high thermal conductivity and low loss multi-layer PCB for new energy vehicles, comprising: A PCB body, the PCB body comprising a circuit layer, a sandwich insulation layer, and a substrate layer, the sandwich insulation layer being disposed between the circuit layer and the substrate layer, with at least two layers of the sandwich insulation layer being located on opposite sides of the substrate layer; the sandwich insulation layer comprising a thermally conductive insulating adhesive and a thermally conductive film, the thermally conductive film being sandwiched within the thermally conductive insulating adhesive, with edges of the thermally conductive film protruding from sides of the thermally conductive insulating adhesive; A first copper plate is covered on the side of the PCB board body, and a shielding space is formed between the first copper plate and the thermal conductive films of each sandwich insulation layer; Second copper sink; A heat-conducting element is embedded in the PCB body and connected to at least one layer of the heat-conducting film through the second copper deposit; the top of the heat-conducting element is exposed in the circuit layer and is used for welding to the heating element; wherein the heat-conducting element is a first-category heat-conducting element or a second-category heat-conducting element, the first-category heat-conducting element is a cylindrical structure and is embedded in the blind hole of the PCB body, the inner wall of the first-category heat-conducting element is connected to at least one layer of the heat-conducting film through the second copper deposit; the second-category heat-conducting element is a solid columnar element and is embedded in the through hole of the PCB body, the outer wall of the second-category heat-conducting element is connected to all the heat-conducting films through the second copper deposit, and the bottom of the second-category heat-conducting element is used for welding to the heat dissipation element.

[0006] The above technical solutions in the embodiments of the present application have at least the following technical effects: In the high-thermal-conductivity, low-loss multi-layer PCB for new energy vehicles provided by this application, first, a special sandwich insulation layer is used to replace the semi-cured sheet of a conventional PCB, and a first copper deposit is formed on the side of the multi-layer PCB. The first copper deposit on the side and the thermal conductive film in the sandwich insulation layer form a shielding space, which can be used as a Faraday cage. The circuits in the multi-layer PCB except the first and last layers are enclosed in the shielding space, which can shield the high-frequency changing magnetic field to solve the problem of high PCB loss caused by the leakage magnetic field of the electric vehicle motor. Secondly, blind hole thermal conductive elements can be used in combination with multiple thermal conductive films for heat dissipation, and through-hole thermal conductive elements are no longer the only ones used. This can solve the problem of excessive volume of existing high-thermal-conductivity multi-layer PCBs.

[0007] In a second aspect, an embodiment of the present application provides a method for preparing a sandwich insulation layer, which is used to manufacture the sandwich insulation layer as described in the first aspect, comprising: Providing a thermal conductive material roll, unwinding a thermal conductive material film from the thermal conductive material roll and passing it through an insulating adhesive pool so that both sides of the thermal conductive material film are evenly soaked with thermal conductive insulating adhesive; wherein the thermal conductive material film is a copper film or an aluminum film; The thermally conductive material film is passed through a scraping device to scrape off excess thermally conductive insulating adhesive, and is semi-cured and cut to a fixed size to obtain a sandwich insulation sheet; According to the first shape of the PCB board body, the sandwich insulation sheet is cut into a second shape, and then the temperature is increased to liquefy the thermally conductive insulating adhesive of the cut sandwich insulation sheet. Then, a fixed depth of the thermally conductive insulating adhesive is scraped off from the edge of the sandwich insulation sheet so that the portion of the sandwich insulation sheet with the thermally conductive insulating adhesive is in the first shape, thereby obtaining the sandwich insulation layer; wherein, the first shape is the shape of the projection of the PCB board body on a set plane, and the second shape is the shape of the projection of the sandwich insulation sheet on the set plane, and the set plane is perpendicular to the stacking direction of the thermally conductive insulating adhesive and the thermally conductive material film. The second shape is similar to the first shape, and the area of ​​the second shape is larger than that of the first shape.

[0008] The above technical solutions in the embodiments of the present application have at least the following technical effects: In the process for preparing a sandwich insulation layer provided by this application, first, both sides of a thermally conductive material film are evenly soaked in thermally conductive insulating adhesive. Then, through adhesive scraping, semi-curing, and cutting, a regular, fixed-size sandwich insulation sheet is obtained. The sandwich insulation sheet is then cut into a second shape based on the first shape, the second shape being a similar image slightly larger than the first shape. Finally, heating is performed to liquefy the thermally conductive insulating adhesive, and a fixed depth of thermally conductive insulating adhesive is scraped off the edges of the second-shaped sandwich insulation sheet, leaving the portion of the sandwich insulation sheet with thermally conductive insulating adhesive in the first shape, thereby obtaining a sandwich insulation layer that meets the requirements. This preparation process can produce a sandwich insulation layer in which a thermally conductive film is sandwiched between the thermally conductive insulating adhesive, and the thermally conductive film has a larger area than the thermally conductive insulating adhesive.

[0009] In a third aspect, an embodiment of the present application provides a preparation process for a high thermal conductivity, low loss multi-layer PCB for new energy vehicles, which is used to manufacture the high thermal conductivity, low loss multi-layer PCB for new energy vehicles as described in the first aspect, comprising: Providing the sandwich insulation layer and the substrate layer with corresponding shapes and numbers, and chemically etching both sides of the substrate layer according to the circuit design to form a circuit; The sandwich insulation layer and the substrate layer are sequentially stacked, and copper deposition and chemical etching are performed on the upper and lower surfaces of the board layer formed after stacking the sandwich insulation layer and the substrate layer to obtain the circuit layer, so as to obtain the PCB board body; determining the type of the heat conducting element according to the heat dissipation requirement level of the heating element; When the thermally conductive component is the first type of thermally conductive component, a blind slot is formed on the component surface of the PCB body, the first type of thermally conductive component is installed in the blind slot, a thermally conductive hole is formed downward from the interior space of the first type of thermally conductive component, and copper is deposited in the thermally conductive hole to obtain the second copper deposit; wherein the thermally conductive hole is a blind hole, passes through at least one layer of the thermally conductive film, and the depth of the thermally conductive hole is proportional to the heat dissipation requirement level; When the heat-conducting component is the second type of heat-conducting component, a first through hole is opened on the PCB board body, copper is deposited in the first through hole to obtain the second copper deposit, and then the second type of heat-conducting component is filled into the first through hole; Solder resist layers are provided on the upper and lower surfaces of the PCB board body, and then copper is deposited on the side to obtain the first copper deposition.

[0010] In fourth aspect, an embodiment of the present application provides a high thermal conductivity, low loss multi-layer PCB preparation device for new energy vehicles, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the method described in any one of the above third aspects is implemented.

[0011] It can be understood that the beneficial effects of the third to fourth aspects can also be found in the relevant description of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 This is a structural diagram of a PCB board body of a high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided in one embodiment of the present application; Figure 2 This is a structural diagram of the first category of heat-conducting elements and the eight-layer PCB body of a high-thermal-conductivity, low-loss multi-layer PCB for new energy vehicles provided in one embodiment of the present application; Figure 3 This is a structural diagram of the second category of heat-conducting elements and the eight-layer PCB body of a high-thermal-conductivity, low-loss multi-layer PCB for new energy vehicles provided in one embodiment of the present application; Figure 4 1 is a schematic flow chart of a method for preparing a sandwich insulation layer provided in one embodiment of the present application; Figure 5This is a schematic flow chart of a process for preparing a high thermal conductivity, low loss multi-layer PCB for new energy vehicles provided in one embodiment of the present application.

[0014] Among them, the reference numerals in the figures are: 100. PCB board body; 1. Circuit layer; 2. Sandwich insulation layer; 21. Thermally conductive film; 22. Thermally conductive insulating adhesive; 3. Substrate layer; 41. First category thermally conductive element; 42. Second category thermally conductive element; 5. Heating element; 61. First copper plate; 62. Second copper plate; 7. Heat dissipation element. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the accompanying drawings are intended to cover non-exclusive inclusions.

[0017] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0018] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0020] In this application, "and / or" is simply a way to describe the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0021] It should be noted that, in this application, words such as "in some embodiments", "exemplarily", "for example", etc. are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "in some embodiments", "exemplarily", "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "in some embodiments", "exemplarily", "for example" is intended to present related concepts in a concrete way, meaning that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the above words in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In related technologies, due to the characteristics of the car's own heat generation and susceptibility to ambient temperature, the PCB used in new energy vehicles must have better thermal conductivity than ordinary PCBs. However, when existing high-thermal-conductivity PCBs are directly used in new energy vehicles, the problems caused by the characteristic scenarios of new energy vehicles are not considered. The problems include: not considering that the electric vehicle's motor may leak magnetic flux, and the high-frequency changing magnetic field leaked by the motor will generate induced current in the PCB circuit, which will increase the circuit loss of the PCB; not considering the compact interior space of the car. Existing high-thermal-conductivity PCBs are usually used for heat conduction by opening through holes. When the PCB is a multi-layer PCB, opening through holes for heat conduction will significantly increase the volume of the multi-layer PCB.

[0023] In order to solve the above problems, the embodiments of the present application provide a high thermal conductivity and low loss multi-layer PCB for new energy vehicles and its preparation process. In the high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided by the present application, first, a special sandwich insulation layer is used to replace the semi-cured sheet of the conventional PCB, and a first copper deposit is formed on the side of the multi-layer PCB. The first copper deposit on the side and the thermal conductive film in the sandwich insulation layer form a Faraday cage, so that the circuits in the multi-layer PCB except the first and last layers are wrapped in a shielding space, which can shield the high-frequency changing magnetic field to solve the problem of high PCB loss caused by the leakage magnetic field of the electric motor of the tram. Secondly, blind hole thermal conductive elements can be used in combination with multiple thermal conductive films for heat dissipation, and through-hole thermal conductive elements are no longer the only ones to be used, which can solve the problem of excessive volume of existing high thermal conductivity multi-layer PCBs.

[0024] In order to better understand the high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided in the embodiment of the present application, the high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided in the embodiment of the present application is introduced below in diagram form.

[0025] Please also refer to Figures 1 to 3 The present application provides a high thermal conductivity and low loss multi-layer PCB for new energy vehicles, including a PCB board body 100, a first type of thermal conductive element 41, a second type of thermal conductive element 42, a first copper plate 61, and a second copper plate 62, wherein: The PCB body 100 includes a circuit layer 1, a sandwich insulation layer 2, and a substrate layer 3. The sandwich insulation layer 2 is disposed between the circuit layer 1 and the substrate layer 3, with at least two layers of the sandwich insulation layer 2 located on opposite sides of the substrate layer 3. The sandwich insulation layer 2 includes a thermally conductive insulating adhesive 22 and a thermally conductive film 21. The thermally conductive film 21 is sandwiched within the thermally conductive insulating adhesive 22, with the edges of the thermally conductive film 21 protruding from the sides of the thermally conductive insulating adhesive 22. The first copper plate 61 covers the side of the PCB body 100 , and a shielding space is formed between the first copper plate 61 and the thermal conductive film 21 of each sandwich insulation layer 2 ; The thermal conductive element is embedded in the PCB body 100 and is connected to at least one layer of thermal conductive film 21 via a second copper plate 62. The top of the thermal conductive element is exposed on the circuit layer 1 for soldering to the heating element 5. The thermal conductive element is a first-category thermal conductive element 41 or a second-category thermal conductive element 42. The first-category thermal conductive element 41 is a cylindrical structure embedded in a blind hole of the PCB body 100. The inner wall of the first-category thermal conductive element 41 is connected to at least one layer of thermal conductive film 21 via a second copper plate 62. The second-category thermal conductive element 42 is a solid columnar element embedded in a through hole of the PCB body 100. The outer wall of the second-category thermal conductive element 42 is connected to all thermal conductive films 21 via a second copper plate 62. The bottom of the second-category thermal conductive element 42 is soldered to the heat dissipation element 7.

[0026] It can be understood that the circuit layer is a layer used for circuit routing and soldering electronic components. For example, the circuit layer 1 can be etched from copper foil or other conductive materials. The sandwich insulation layer 2 is a layer used to isolate the circuit and conduct heat. It is semi-cured from a thermally conductive film 21 and a thermally conductive insulating adhesive 22. For example, the thermally conductive insulating adhesive 22 can be an epoxy resin containing high thermal conductivity ceramic powder, and the thermally conductive film 21 can be a film made of various high thermal conductivity materials. The substrate layer 3 is a layer used to carry the inner layer circuit. It can be a conventional PCB substrate. A conventional PCB substrate consists of two layers of copper foil sandwiching a layer of semi-cured sheet. The first category of thermal conductive elements 41 and the second category of thermal conductive elements 42 are both used to conduct heat from the heating element. For example, the thermal conductive elements can be made of copper, copper alloy, aluminum or aluminum alloy. The heating element 5 is an electronic component that generates heat and is soldered on the PCB board body 100, such as a resistor, capacitor, etc. The first copper deposition 61 and the second copper deposition 62 are both copper films formed by the copper deposition process. The first copper deposition 61 is used to connect all thermal conductive films and form a shielding space. The heat dissipation element 7 can be a multi-toothed element made of copper, copper alloy, aluminum or aluminum alloy.

[0027] It is understood that the high-thermal-conductivity, low-loss multilayer PCB provided by this application differs primarily from conventional PCBs in that a sandwich insulation layer 2 is used instead of a prepreg. The thermally conductive film 21 within the sandwich insulation layer 2 provides the PCB provided by this application with multiple heat dissipation pathways, eliminating the need for heat to be dissipated solely from the bottom of the PCB. This allows thermally conductive elements to be placed in blind vias, significantly saving wiring space within the multilayer PCB. Furthermore, a first copper plate 61 is provided on the side of the PCB, further accelerating heat dissipation. The first copper plate 61 also forms a Faraday cage with the thermally conductive film 21, minimizing the effects of external magnetic fields and reducing losses in the PCB circuits.

[0028] From the above, it can be seen that the high thermal conductivity and low loss multi-layer PCB board for new energy vehicles provided in this application is very suitable for new energy electric vehicles, especially electric vehicles with motors. It can not only achieve high thermal conductivity and low loss, but also further reduce the volume of the PCB board.

[0029] Optionally, an outer wall of the second type of heat conducting element 42 is provided with threads, and the second type of heat conducting element 42 is connected to the second copper sink 62 via the threads.

[0030] It can be understood that there is no further reinforced connection between the second type of thermal conductive element 42 and the second copper plate 62, and there may be a gap between the two. Therefore, the second type of thermal conductive element 42 is designed as a screw-shaped element, and the second type of thermal conductive element 42 is screwed into the through hole. The threads on the second type of thermal conductive element 42 can also be further squeezed together with the second copper plate 62 to strengthen the connection.

[0031] Such a configuration can prevent the second type of heat conducting element 42 from falling off or being loosely connected.

[0032] Optionally, further, the second category thermal conductive element 42 includes a thermal conductive element body and a nut, the nut is connected to the top of the thermal conductive element body, and the outer wall of the thermal conductive element body is provided with a thread; the nut is used to separate from the thermal conductive element body after the thermal conductive element body is connected to the second copper plating 62 through the thread.

[0033] It can be understood that the heat-conducting element body and the nut can be connected by external materials, such as glue or other adhesive materials, or by a more fragile body structure, such as cutting at the connection to make the structure at the connection thinner. Therefore, after the heat-conducting element body is screwed into the through hole and connected to the second copper plating 62 by the nut, the nut can be separated from the heat-conducting element body.

[0034] Such an arrangement improves the installation efficiency of the second type of heat conducting elements 42 .

[0035] Optionally, the heat-conducting films 21 are all grounded.

[0036] It can be understood that all thermally conductive films 21 and all first copper deposits 61 and second copper deposits 62 are electrically connected together. If this circuit is left vacant, it may cause circuit signal drift, resulting in increased circuit loss of the PCB. Therefore, all thermally conductive films 21 are grounded, the circuit layer 1 on the lower surface can be grounded as a whole, and the first copper deposit 61 is electrically connected to the circuit layer 1 on the lower surface, so that all thermally conductive films 21 and all first copper deposits 61 and second copper deposits 62 are grounded.

[0037] Such an arrangement improves the stability of the PCB provided in this application.

[0038] Optionally, the heat-conducting element is made of copper, copper alloy, aluminum or aluminum alloy; and the substrate layer is an aluminum substrate.

[0039] It is understood that the use of an aluminum substrate can further enhance the heat dissipation performance of the PCB provided in this application. However, the side sealant of the aluminum substrate must be polished clean to connect the aluminum layer of the aluminum substrate with the first copper plate 61 to further improve the heat dissipation effect. The thermal conductive element is made of copper, copper alloy, aluminum, or aluminum alloy to improve the thermal conductivity.

[0040] Such an arrangement can further improve the heat dissipation effect.

[0041] In order to better understand the sandwich insulation layer preparation process provided in the embodiment of the present application, the specific implementation process of the sandwich insulation layer preparation process provided in the embodiment of the present application is exemplarily introduced below.

[0042] Figure 4 The figure shows a process flow diagram of a sandwich insulation layer preparation process provided by an embodiment of the present application. The process of preparing the sandwich insulation layer includes: S100: A thermal conductive material roll is provided, and a thermal conductive material film is unwound from the thermal conductive material roll and passed through an insulating adhesive pool so that both sides of the thermal conductive material film are evenly soaked with thermal conductive insulating adhesive. The thermal conductive material film is a copper film or an aluminum film.

[0043] It can be understood that the thermal conductive material film can be unwound at a uniform speed by the unwinding machine. The thermal conductive material film is a copper film or an aluminum film, and the thickness can be 0.1mm. The thermal conductive material film passes through the insulating glue pool, and the insulating glue pool contains thermal conductive insulating glue. Two insulating glue pools can be set up, and the two sides of the thermal conductive material roll are allowed to pass through the two insulating glue pools facing down, so that both sides of the thermal conductive material film are evenly soaked with the same amount of thermal conductive insulating glue. The insulating glue pool can automatically replenish glue at a fixed speed.

[0044] Optionally, fiberglass cloth may be laid on both sides of the thermal conductive material film to increase the tensile strength of the thermal conductive material film.

[0045] By setting it in this way, a thermal conductive material film with thermal conductive insulating adhesive evenly coated on both sides is obtained.

[0046] S200 , passing the thermal conductive material film through a scraping device to scrape off excess thermal conductive insulating adhesive, and then semi-curing and cutting the film into fixed sizes to obtain a sandwich insulating sheet.

[0047] It can be understood that the scraping device can be one or more scraping rollers, which pass the thermal conductive material film through the scraping rollers to scrape off the excess thermal conductive insulating glue on both sides, and then semi-curing is carried out. The semi-curing methods of thermal conductive insulating glue of different materials are different. Some are ultraviolet curing, and some are high temperature and high pressure curing. After semi-curing, the thermal conductive insulating glue becomes a semi-liquid colloid. The thermal conductive material film can be spread flat on a smooth aluminum conveyor belt to prevent the thermal conductive material film from adhering to the conveyor belt, and then cut into a fixed size to obtain a sandwich insulation sheet.

[0048] By setting it in this way, a regular sandwich insulation sheet is obtained, so that sandwich insulation layers of corresponding shapes can be cut out according to PCBs of different shapes in the future.

[0049] S300: Based on the first shape of the PCB body 100, the sandwich insulation sheet is cut into a second shape. The temperature is then raised to liquefy the thermally conductive insulating adhesive in the cut sandwich insulation sheet. A predetermined depth of the thermally conductive insulating adhesive is then scraped off from the edge of the sandwich insulation sheet, leaving the portion of the sandwich insulation sheet with the thermally conductive insulating adhesive in the first shape. This results in the sandwich insulation layer 2. The first shape is the projection of the PCB body 100 onto a predetermined plane, and the second shape is the projection of the sandwich insulation sheet onto the predetermined plane. The predetermined plane is perpendicular to the stacking direction of the thermally conductive insulating adhesive and the thermally conductive material film. The second shape is similar to the first shape, and the second shape has a larger area than the first shape.

[0050] As can be understood, the characteristic of the sandwich insulation layer 2 is that the area of ​​the internal thermally conductive film 21 is slightly larger than that of the thermally conductive insulating adhesive 22, resulting in a protrusion of the thermally conductive film 21 on the side of the sandwich insulation layer 2. Therefore, a second shape is obtained based on the first shape. The second shape is slightly larger than the first shape and has a similar shape to the first shape. The second shape is the projection of the thermally conductive film 21 onto a predetermined plane, while the first shape is the projection of the thermally conductive insulating adhesive 22 onto the predetermined plane. The predetermined plane is a plane perpendicular to the stacking direction of the thermally conductive insulating adhesive and the thermally conductive material film (i.e., the component surface). Therefore, the shape of the thermally conductive film 21 also reflects the shape of the sandwich insulation layer 2, and the shape of the thermally conductive insulating adhesive 22 also reflects the shape of the PCB body 100. After obtaining the second shape, the sandwich insulation sheet is first cut into the second shape. Then, the temperature is increased to liquefy the thermally conductive insulating adhesive. A predetermined depth of thermally conductive insulating adhesive is then scraped off from the edge of the second-shaped sandwich insulation sheet, leaving the portion of the sandwich insulation sheet with thermally conductive insulating adhesive in the first shape. This completes the sandwich insulation layer 2.

[0051] With such an arrangement, the sandwich insulation layer 2 provided in the present application can be obtained.

[0052] In order to better understand the preparation process of the high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided in the embodiment of the present application, the specific implementation process of the preparation process of the high thermal conductivity and low loss multi-layer PCB for new energy vehicles provided in the embodiment of the present application is exemplarily introduced below.

[0053] Figure 5 The following is a schematic diagram showing a process for preparing a high thermal conductivity, low loss multi-layer PCB for new energy vehicles provided in an embodiment of the present application. The process for preparing a high thermal conductivity, low loss multi-layer PCB for new energy vehicles includes: S400 , providing a sandwich insulation layer 2 and a substrate layer 3 of corresponding shape and number, and chemically etching both sides of the substrate layer 3 according to the circuit design to form a circuit.

[0054] It can be understood that after the PCB is designed, the corresponding shapes and numbers of sandwich insulation layers 2 and substrate layers 3 are obtained. If the PCB is an N-layer board, the number of sandwich insulation layers 2 is N / 2, and the number of substrate layers 3 is (N / 2)-1. Each substrate layer 3 is pre-numbered, and the number represents the order of the substrate layers 3 from bottom to top. After the numbering of the substrate layers 3 is determined, the corresponding circuit is chemically etched on both sides of each substrate layer 3 according to the circuit design of the PCB.

[0055] With this arrangement, the sandwich insulation layer 2 and the substrate layer 3 are processed, and the corresponding circuits are etched, completing the first step of PCB manufacturing.

[0056] S500 , stacking the sandwich insulation layer 2 and the substrate layer 3 in sequence, and performing copper deposition and chemical etching on the upper and lower surfaces of the board layer formed after stacking the sandwich insulation layer 2 and the substrate layer 3 to obtain the circuit layer 1 , so as to obtain the PCB board body 100 .

[0057] It can be understood that after obtaining the processed sandwich insulation layer 2 and substrate layer 3, the sandwich insulation layer 2 and substrate layer 3 are stacked in the order of numbering. For example, the stacking order of the four-layer board is: sandwich insulation layer 21->substrate layer 31->sandwich insulation layer 2. During the stacking process, the thermal conductive insulation glue 22 of the sandwich insulation layer 2 is completely cured, and the sandwich insulation layer 2 and the substrate layer 3 are tightly bonded. Subsequently, copper is deposited on the upper and lower surfaces of the stacked board layer to form copper foil, and then the copper foil is chemically etched to obtain the circuit layer 1, and components can be soldered on the circuit layer 1.

[0058] With such configuration, the prototype of the PCB, ie, the PCB board body 100 , is manufactured.

[0059] S600 , determining the type of the heat conducting element according to the heat dissipation requirement level of the heating element 5 .

[0060] It can be understood that different types of electronic components have different amounts of heat generated, and different amounts of heat generated can be divided into different heating levels. The heat resistance of the electronic components can be further considered, and different heat resistances can be divided into different heat resistance levels. Therefore, the heat dissipation requirement level of the heating element 5 = the heat generation level - the heat resistance level. After obtaining the heat dissipation requirement level of the heating element 5, a level threshold can be determined. The heating element 5 with a heat dissipation requirement level greater than this level threshold will adopt the second category heat conducting element 42; the heating element 5 with a heat dissipation requirement level less than this level threshold will adopt the first category heat conducting element 41.

[0061] In this configuration, the second type of heat conducting elements 42 are allocated according to the heat dissipation requirements of the components, which can reduce the number of through holes on the PCB board and further reduce the volume of the PCB.

[0062] Optionally, determining the heat dissipation requirement level of the heating element 5 includes: S610 , obtaining the heating power and total number of the heating elements 5 , and then obtaining the thermal conductivity power of a single thermally conductive film 21 .

[0063] It can be understood that the heating power of the heating element 5 refers to the heat generated by the heating element 5 when working at the rated power per unit time, the total number refers to the number of heating elements 5 on the PCB, and the thermal conductivity power of the thermal conductive film 21 refers to the heat transferred by the thermal conductive film 21 per unit time, which is equal to the thermal conductivity coefficient of the thermal conductive film 21 multiplied by the cross-sectional area of ​​the thermal conductive film 21.

[0064] Such an arrangement is helpful for calculating the heat dissipation requirement level of each heating element 5 .

[0065] S620 , dividing the heating power by the thermal conductivity power to obtain a first ratio, and then multiplying the first ratio by the number of heating elements 5 to obtain a heat dissipation requirement level of the heating elements 5 .

[0066] It can be understood that heating power / thermal conduction power = first ratio. The physical meaning of the first ratio can be expressed as the heating element 5 requires N thermal conductive films 21 for heat conduction, where N is the first ratio. However, it is impossible for there to be only one heating element 5 on the PCB. If there are M heating elements 5 on the PCB and it is assumed that all heating elements 5 have the same heat generation, then on average, a total of N×M thermal conductive films 21 are required for heat conduction. Therefore, the first ratio is multiplied by the total number of heating elements 5 to obtain the heat dissipation requirement level of the heating element 5. At this time, the physical meaning of the heat dissipation requirement level can be expressed as the heating element 5 needs to be connected to X thermal conductive films 21, where X is the heat dissipation requirement level.

[0067] This setting clarifies the physical meaning of the heat dissipation requirement level and equates the heat dissipation requirement level of the heating element 5 with the number of connected thermal conductive films 21, which is conducive to the subsequent determination of the depth of the thermal conductive holes in the first category of thermal conductive elements 41.

[0068] Furthermore, the type of the heat conducting element is determined according to the heat dissipation requirement level of the heating element 5, including: S630 , when the heat dissipation requirement level of the heating element 5 is greater than the number of the thermally conductive films 21 , the category of the thermally conductive element is the second category thermally conductive element 42 ; otherwise, the category of the thermally conductive element is the first category thermally conductive element 41 .

[0069] It can be understood that the physical meaning of the heat dissipation requirement level can be expressed as the heating element 5 needs to be connected to X thermal conductive films 21. Therefore, when the heat dissipation requirement level of the heating element 5 is greater than the number of PCB thermal conductive films 21, the second type of thermal conductive elements 42 can be drilled to conduct heat for the heating element 5. When the heat dissipation requirement level of the heating element 5 is less than the number of PCB thermal conductive films 21, the first type of thermal conductive elements 41 and blind holes are directly used to conduct heat for the heating element 5.

[0070] Such an arrangement not only leaves sufficient heat conduction efficiency for each heating element 5, but also reduces the number of through holes, thus saving wiring space on the PCB to the greatest extent.

[0071] S700: If the thermally conductive component is a first-type thermally conductive component 41, a blind slot is formed on the component surface of the PCB body 100. The first-type thermally conductive component 41 is installed in the blind slot. A thermally conductive via is then formed downward from the interior space of the first-type thermally conductive component 41, and copper is deposited in the thermal via to form a second copper deposit 62. The thermal via is a blind via and passes through at least one layer of thermally conductive film 21. The depth of the thermal via is proportional to the required heat dissipation level.

[0072] It is understandable that Figure 1 and Figure 2 As shown, the heat dissipation method of the first type of heat-conducting element 41 in conjunction with the blind hole is: first, a blind groove is opened on the component surface of the PCB board body 100. The depth of the blind groove can be fixed. Specifically, the depth can be the depth of passing through a layer of sandwich insulation layer 2. Then, the first type of heat-conducting element 41 is filled in the blind groove. Then, a heat-conducting hole is opened downward from the hollow part of the first type of heat-conducting element 41. The heat-conducting hole passes through at least one layer of heat-conducting film 21, and the depth of the heat-conducting hole is proportional to the heat dissipation requirement level of the heating element 5. After the heat-conducting hole is opened, copper is deposited in the heat-conducting hole to obtain a second copper deposit 62. The second copper deposit 62 allows the first type of heat-conducting element 41 and the multiple heat-conducting films 21 to be thermally and electrically connected together, so that the heat of the heating element 5 is transferred from the multiple heat-conducting films 21 to the first copper deposit 61.

[0073] S800, when the heat conducting component is the second type heat conducting component 42, a first through hole is opened on the PCB board body 100, and copper is deposited in the first through hole to obtain a second copper deposit 62, and then the second type heat conducting component 42 is filled into the first through hole.

[0074] like Figure 1 and Figure 3 As shown, the heat dissipation method of the second type of thermal conductive element 42 in conjunction with the through hole is: a first through hole is opened on the PCB board body 100, and then copper is deposited in the first through hole to form a second copper deposit 62. The second copper deposit 62 is thermally and electrically connected to all the thermal conductive films 21. Then, the second type of thermal conductive element 42 is filled into the first through hole. The second type of thermal conductive element 42 fits tightly with the second copper deposit 62, and the second type of thermal conductive element 42 can be screw-shaped to further enhance the fit. Finally, the heat dissipation element 7 is soldered to the bottom of the second type of thermal conductive element 42, so that the heat of the heating element 5 can not only flow from the thermal conductive film 21 to the first copper deposit 61, but also be quickly dissipated through the heat dissipation element 7.

[0075] With this arrangement, two types of thermal conductive elements and corresponding multi-layer PCB boards can be manufactured.

[0076] Optionally, before the sandwich insulation layer 2 and the substrate layer 3 are stacked, blind holes or through holes are drilled in the corresponding sandwich insulation layer 2 and the substrate layer 3, and then the sandwich insulation layer 2 and the substrate layer 3 are stacked in sequence.

[0077] They can be connected. Before stacking the sandwich insulation layer 2 and the substrate layer 3, blind holes or through holes can be drilled on the sandwich insulation layer 2 and the substrate layer 3 with corresponding numbers. Then the sandwich insulation layer 2 and the substrate layer 3 can be stacked in sequence. After the stacking is completed, the blind holes or through holes can be polished multiple times to make the inner walls of the blind holes or through holes smoother.

[0078] This arrangement can prevent waste from accumulating in the hole during drilling, thereby reducing the surface quality of the inner wall of the hole.

[0079] S900 , a solder resist layer is provided on the upper and lower surfaces of the PCB main body 100 , and then copper is deposited on the side to obtain a first copper deposit 61 .

[0080] It can be understood that after the punching is completed, a solder mask layer is laid on the double-sided circuit layer 1 to prevent the circuit layer 1 from being damaged during the welding process, and then copper is deposited on the side of the PCB board body 100 to obtain the first copper deposit 61.

[0081] This arrangement prevents the circuit layer 1 from being damaged during the welding process, and also prevents the first copper deposit 61 from being electrically connected to the circuit layer 1 when copper is deposited on the side of the PCB 100, causing the circuit layer 1 to be short-circuited or grounded.

[0082] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0083] An embodiment of the present application also provides a high thermal conductivity, low loss multi-layer PCB manufacturing device for new energy vehicles, which is used to manufacture the high thermal conductivity, low loss multi-layer PCB for new energy vehicles described in any of the above embodiments.

[0084] For example, the equipment for preparing high-thermal-conductivity, low-loss multi-layer PCBs for new energy vehicles may include an etching device, a laminating device, a hole-punching device, a copper-plating device, a welding device, and a control device. The etching device may be a common PCB etching machine, the laminating device may be a common PCB laminating machine, the hole-punching device may be a CNC machine tool or a PCB-specific drilling machine, the copper-plating device may be a common PCB copper-plating machine, and the welding device may be an automatic component welding machine. The control device may control the etching device to etch the corresponding circuit, control the laminating device to laminate the sandwich insulation layer and the substrate layer, determine the type of thermal conductive element based on the heat dissipation requirement level of the heating element, control the hole-punching device to drill blind holes or through holes on the PCB, control the copper-plating device to deposit copper on the PCB, and control the welding device to automatically solder components on the PCB.

[0085] For example, the control manufacturing can be a single chip microcomputer, a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a desktop computer, a computer, a laptop computer, etc.

[0086] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A high thermal conductivity and low loss multi-layer PCB for new energy vehicles, characterized in that: include: A PCB body, the PCB body comprising a circuit layer, a sandwich insulation layer, and a substrate layer, the sandwich insulation layer being disposed between the circuit layer and the substrate layer, with at least two layers of the sandwich insulation layer being located on opposite sides of the substrate layer; the sandwich insulation layer comprising a thermally conductive insulating adhesive and a thermally conductive film, the thermally conductive film being sandwiched within the thermally conductive insulating adhesive, with edges of the thermally conductive film protruding from sides of the thermally conductive insulating adhesive; A first copper plate is covered on the side of the PCB board body, and a shielding space is formed between the first copper plate and the thermal conductive films of each sandwich insulation layer; Second copper sink; A heat-conducting element, wherein the heat-conducting element is embedded in the PCB board body and connected to at least one layer of the heat-conducting film through the second copper deposit; The top of the thermally conductive element is exposed in the circuit layer and is used for welding with the heating element; wherein, the thermally conductive element is a first category thermally conductive element or a second category thermally conductive element, the first category thermally conductive element is a cylindrical structure and is buried in the blind hole of the PCB board body, the inner wall of the first category thermally conductive element is connected to at least one layer of the thermally conductive film through the second copper deposition; the second category thermally conductive element is a solid columnar element and is buried in the through hole of the PCB board body, the outer wall of the second category thermally conductive element is connected to all the thermally conductive films through the second copper deposition, and the bottom of the second category thermally conductive element is used for welding with the heat dissipation element.

2. The high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 1, characterized in that: The outer side wall of the second type of heat conducting element is provided with a thread, and the second type of heat conducting element is connected to the second copper sink through the thread.

3. The high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 1, characterized in that: The second category of heat-conducting elements includes a heat-conducting element body and a nut, wherein the nut is connected to the top of the heat-conducting element body, and the outer wall of the heat-conducting element body is provided with threads; the nut is used to separate from the heat-conducting element body after the heat-conducting element body is connected to the second copper plating through the threads.

4. The high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 1, characterized in that: The thermally conductive films are all grounded.

5. The high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 1, characterized in that: The heat conducting element is made of copper, copper alloy, aluminum or aluminum alloy; The substrate layer is an aluminum substrate.

6. A method for preparing a sandwich insulation layer, for manufacturing the sandwich insulation layer according to claim 1, characterized in that: The method for preparing the sandwich insulation layer comprises: Providing a thermal conductive material roll, unwinding a thermal conductive material film from the thermal conductive material roll and passing it through an insulating adhesive pool so that both sides of the thermal conductive material film are evenly soaked with thermal conductive insulating adhesive; wherein the thermal conductive material film is a copper film or an aluminum film; The thermally conductive material film is passed through a scraping device to scrape off excess thermally conductive insulating adhesive, and is semi-cured and cut to a fixed size to obtain a sandwich insulation sheet; According to the first shape of the PCB board body, the sandwich insulation sheet is cut into a second shape, and then the temperature is increased to liquefy the thermally conductive insulating adhesive of the cut sandwich insulation sheet. Then, a fixed depth of the thermally conductive insulating adhesive is scraped off from the edge of the sandwich insulation sheet so that the portion of the sandwich insulation sheet with the thermally conductive insulating adhesive is in the first shape, thereby obtaining the sandwich insulation layer; wherein, the first shape is the shape of the projection of the PCB board body on a set plane, and the second shape is the shape of the projection of the sandwich insulation sheet on the set plane, and the set plane is perpendicular to the stacking direction of the thermally conductive insulating adhesive and the thermally conductive material film. The second shape is similar to the first shape, and the area of ​​the second shape is larger than that of the first shape.

7. A process for preparing a high thermal conductivity, low loss multilayer PCB for new energy vehicles, for manufacturing the high thermal conductivity, low loss multilayer PCB for new energy vehicles according to any one of claims 1 to 5, characterized in that: The high thermal conductivity and low loss multi-layer PCB preparation process for new energy vehicles includes: Providing the sandwich insulation layer and the substrate layer with corresponding shapes and numbers, and chemically etching both sides of the substrate layer according to the circuit design to form a circuit; The sandwich insulation layer and the substrate layer are sequentially stacked, and copper deposition and chemical etching are performed on the upper and lower surfaces of the board layer formed after stacking the sandwich insulation layer and the substrate layer to obtain the circuit layer, so as to obtain the PCB board body; determining the type of the heat conducting element according to the heat dissipation requirement level of the heating element; When the thermally conductive component is the first type of thermally conductive component, a blind slot is formed on the component surface of the PCB body, the first type of thermally conductive component is installed in the blind slot, a thermally conductive hole is formed downward from the interior space of the first type of thermally conductive component, and copper is deposited in the thermally conductive hole to obtain the second copper deposit; wherein the thermally conductive hole is a blind hole, passes through at least one layer of the thermally conductive film, and the depth of the thermally conductive hole is proportional to the heat dissipation requirement level; When the heat-conducting component is the second type of heat-conducting component, a first through hole is opened on the PCB board body, copper is deposited in the first through hole to obtain the second copper deposit, and then the second type of heat-conducting component is filled into the first through hole; Solder resist layers are provided on the upper and lower surfaces of the PCB board body, and then copper is deposited on the side to obtain the first copper deposition.

8. The process for preparing a high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 7, wherein: Determining the heat dissipation requirement level of the heating element includes: Obtaining the heating power and total number of the heating elements, and then obtaining the thermal conductivity of a single thermally conductive film; The heat generation power is divided by the heat conduction power to obtain a first ratio, and the first ratio is multiplied by the total number of the heat generation components to obtain the heat dissipation requirement level of the heat generation components.

9. The process for preparing a high thermal conductivity and low loss multi-layer PCB for new energy vehicles according to claim 8, wherein: Determining the type of the heat conducting element according to the heat dissipation requirement level of the heating element includes: When the heat dissipation requirement level of the heat-generating element is greater than the number of the heat-conducting films, the category of the heat-conducting element is determined to be the second category heat-conducting element; otherwise, the category of the heat-conducting element is determined to be the first category heat-conducting element.

10. A high thermal conductivity and low loss multi-layer PCB manufacturing equipment for new energy vehicles, characterized in that: Used to prepare a high thermal conductivity and low loss multi-layer PCB for new energy vehicles as described in any one of claims 1 to 5.

Images