Double-sided copper block multilayer circuit board
Through the compressed stacked structure of the double-sided copper block multi-layer circuit board, the problem of difficulty in double-sided current carrying and insufficient heat dissipation of the circuit board is solved, and efficient double-sided current carrying and optimized heat dissipation effect is achieved.
Patent Information
- Application Number
- CN202422032517.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-21
AI Technical Summary
Existing circuit boards are difficult to achieve double-sided current carrying capacity and lack of heat dissipation performance, especially under high-power operating conditions, it is difficult to meet the heat dissipation needs of electric vehicles.
The double-sided copper block multi-layer circuit board structure is adopted, and the copper block is combined with the outer heat dissipation core board and the circuit core board through a press-fit stacking structure to avoid the fitting process, ensure that the copper block is arranged on the same plane, and achieve double-sided current carrying and optimized heat dissipation.
The surface flatness and overall thickness control of the circuit board are improved, and the current carrying demand for excessive current on both sides is met, the optimal heat dissipation mode is achieved, and the heat dissipation efficiency is improved.
Smart Images
Figure CN223080205U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of circuit boards, and particularly to a double-sided copper block multi-layer circuit board. Background Art
[0002] With the development of printed circuit boards (PCBs), the requirement for heat dissipation performance is getting higher and higher. Especially, the power assembly circuit boards used in electric vehicles operate at high power and require effective heat dissipation.
[0003] In related technologies, the thermal management solution for circuit boards is to embed copper grains into electroplated vias or bury copper blocks in the inner layer of the circuit board. However, it is difficult to strictly control the surface flatness and overall thickness of the circuit board, and double-sided current carrying cannot be achieved, making it difficult to pass large currents on both sides simultaneously to achieve the best heat dissipation mode. Summary of the Utility Model
[0004] Based on this, it is necessary to provide a double-sided copper block multi-layer circuit board to solve the problem that the circuit board in related technologies cannot achieve double-sided current carrying and is difficult to pass large currents on both sides simultaneously to achieve the best heat dissipation mode.
[0005] A double-sided copper block multi-layer circuit board includes:
[0006] Two outer layer heat dissipation core boards, each of the outer layer heat dissipation core boards includes a first base layer, an outer circuit layer provided on the outer side of the first base layer, and a heat dissipation layer provided on the inner side of the first base layer, and the heat dissipation layer includes a plurality of copper blocks;
[0007] At least two circuit core boards, stacked between the two outer layer heat dissipation core boards, at least one side of the circuit core board is formed with a circuit, and the plurality of copper blocks of the heat dissipation layer are arranged opposite to the circuits of the adjacent circuit core boards; and
[0008] A plurality of insulating layers, the insulating layers are provided between the outer layer heat dissipation core board and the circuit core board, and between adjacent two circuit core boards, and the two outer layer heat dissipation core boards and at least two circuit core boards are pressed together through the plurality of insulating layers.
[0009] In some embodiments, the shapes of the plurality of copper blocks of the heat dissipation layer are the same as the shapes of the circuits of the adjacent circuit core boards.
[0010] In some embodiments, the heat dissipation layer further includes copper bridges, and the plurality of copper blocks are connected by the copper bridges.
[0011] In some embodiments, the surfaces of the plurality of copper blocks facing away from the first base layer are flush.
[0012] In some embodiments, the thickness range of the copper blocks is 300 microns to 800 microns.
[0013] In some embodiments, the first base layer is a prepreg layer, a fiberglass cloth layer, or a composite material layer; and / or, the outer circuit layer is a copper layer.
[0014] In some embodiments, the circuit core board includes a second base layer and inner circuit layers respectively disposed on opposite sides of the second base layer, and the inner circuit layers are formed with the circuit pattern.
[0015] In some embodiments, the outer layer heat dissipation core board and the circuit core board are both provided with positioning holes.
[0016] In some embodiments, the double-sided copper block multilayer circuit board further includes electroplated through holes, and the electroplated through holes are electrically connected to the outer circuit layers and the copper blocks of the two outer layer heat dissipation core boards and the circuits of the circuit core board.
[0017] In some embodiments, the insulating layer is a resin layer or a prepreg layer.
[0018] The above double-sided copper block multilayer circuit board adopts a press-fitting stack structure. The buried copper blocks do not need to go through an embedding process, avoiding matching problems caused by dimensional tolerances, reducing the precision requirements for controlling processing dimensional tolerances, and facilitating the control of the overall thickness of the circuit board, which is beneficial to reducing the overall thickness of the double-sided copper block multilayer circuit board; multiple copper blocks are arranged on the same plane, avoiding flatness problems of the circuit board caused by thickness differences of the buried copper blocks, and improving the flatness of the surface of the double-sided copper block multilayer circuit board; two outer layer heat dissipation core boards can embed / bury multiple copper blocks at the same position in the press-fitting stack direction of the double-sided copper block multilayer circuit board, so as to achieve double-sided current carrying, meet the current carrying requirements of passing large currents simultaneously on both sides of the circuit board, and is beneficial to achieving the best heat dissipation mode and effectively improving the heat dissipation efficiency of the double-sided copper block multilayer circuit board. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a schematic cross-sectional structure diagram of a double-sided copper block multilayer circuit board according to some embodiments of the present application.
[0020] Figure 2 is a partial structure schematic diagram of an outer layer heat dissipation core board according to some embodiments of the present application.
[0021] Reference Numerals in the Drawings:
[0022] 100, double-sided copper block multilayer circuit board; 1, outer layer heat dissipation core board; 11, first base layer; 12, outer circuit layer; 13, heat dissipation layer; 131, copper block; 2, circuit core board; 21, second base layer; 22, inner circuit layer; 3, insulating layer. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] To make the above objects, features, and advantages of the present application more obvious and understandable, the following provides a detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.
[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.
[0025] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0026] In the present application, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0027] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath", and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0028] It should be noted that an element is referred to as being "fixed to" or "disposed on" another element, and it can be directly on the other element or there can also be an intermediate element. An element is considered to be "connected to" another element, and it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.
[0029] With the development of electric vehicle technology, higher requirements are put forward for high-current carriers in the market, such as the need for both sides of the circuit board to carry large currents simultaneously to achieve the best heat dissipation mode.
[0030] In the related art, a buried copper heat dissipation method is introduced into the circuit board. The copper particles are fitted with electroplated through holes. The positions on the circuit board corresponding to the embedded copper particles are processed with electroplated through holes according to size requirements, and then the copper particles are pressed by a fitting machine to match the electroplated through holes. The existing copper particle diameters are 8.2 mm, 10.2 mm, 12.2 mm, etc., and electroplated through holes with large sizes need to be matched. However, it is difficult to strictly control the size tolerances of the electroplated copper holes or the copper particle sizes in the processing flow, and there is a risk of copper particle dropping during the fitting process. Moreover, there are problems such as a thickness difference between the copper particles and the circuit board surface, resulting in difficulty in controlling the flatness between the copper particles and the circuit board surface. In addition, some also put copper particles into the inner layer at corresponding positions before the circuit board pressing process, and then carry out processes such as pressing and drilling. However, usually only one copper block is placed at a single position, and double-sided current carrying cannot be achieved. Moreover, when embedding copper blocks before pressing the circuit board, it is difficult to control the thickness tolerance of the circuit board. Therefore, the control of the size tolerance of the finishing holes, the flatness between the copper particles and the circuit board surface, and the control of the overall thickness of the circuit board have all faced great challenges.
[0031] Referring to Figure 1 and Figure 2 , Figure 1 shows a schematic cross-sectional structure diagram of a double-sided copper block multi-layer circuit board in some embodiments of the present application. Figure 2The figure shows a partial structural schematic diagram of an outer heat dissipation core board in some embodiments of the present application; the double-sided copper block multi-layer circuit board 100 provided by the embodiments of the present application includes two outer heat dissipation core boards 1, at least two circuit core boards 2, and a plurality of insulating layers 3; the outer heat dissipation core board 1 includes a first base layer 11, an outer circuit layer 12 provided on the outer side of the first base layer 11, and a heat dissipation layer 13 provided on the inner side of the first base layer 11, the heat dissipation layer 13 includes a plurality of copper blocks 131; at least two circuit core boards 2 are stacked between the two outer heat dissipation core boards 1, and circuits are formed on at least one side of the circuit core board 2, and the plurality of copper blocks 131 of the heat dissipation layer 13 are arranged opposite to the circuits of the adjacent circuit core board 2; insulating layers 3 are provided between the outer heat dissipation core board 1 and the circuit core board 2 and between adjacent two circuit core boards 2, and the two outer heat dissipation core boards 1 and at least two circuit core boards 2 are pressed together through a plurality of insulating layers 3.
[0032] The first base layer 11 can be a board or sheet made of an insulating material; the first base layer 11 has an outer side surface and an inner side surface arranged opposite to each other, the outer side surface is used to face the outside of the double-sided copper block multi-layer circuit board 100, the side where the outer side surface of the first base layer 11 faces is the outside of the first base layer 11, the inner side surface is used to face the inside of the double-sided copper block multi-layer circuit board 100, and the side where the inner side surface of the first base layer 11 faces is the inside of the first base layer 11. The outer circuit layer 12 can be a film layer made of a conductive material; the outer circuit layer 12 can be formed with a circuit pattern; the outer circuit layer 12 is fixed on the outer side surface of the first base layer 11. A plurality of copper blocks 131 are fixed on the inner side surface of the first base layer 11, thereby forming the heat dissipation layer 13, that is to say, a plurality of copper blocks 131 are arranged on the same plane to avoid the problem of thickness difference caused by a single copper block 131. The outer heat dissipation core board 1 has a structure in which the copper blocks 131, the first base layer 11, and the outer circuit layer 12 are stacked in sequence, so that the outer heat dissipation core board 1 can be processed and manufactured by a pressing process without going through the processes of drilling and fitting.
[0033] The circuit core board 2 can be a semi-finished circuit board with pre-printed circuits. For example, the circuit core board 2 can be a copper clad laminate that has completed the etching process, and the copper layer of the copper clad laminate is formed with a circuit pattern; the circuit core board 2 can be formed with a circuit pattern on one side or both sides, which is not limited herein. The number of circuit core boards 2 can be two, three, four or more, which is not limited herein. A plurality of circuit core boards 2 are stacked, and the circuits of different layers of the circuit core boards 2 are electrically interconnected to perform specific functions.
[0034] The insulating layer 3 is an insulating dielectric layer; a plurality of circuit core boards 2 are stacked between the two outer heat dissipation core boards 1 to form a structure in which the outer heat dissipation core board 1, a plurality of circuit core boards 2, and the outer heat dissipation core board 1 are stacked in sequence, and the two outer heat dissipation core boards 1 and the plurality of circuit core boards 2 are pressed and fixed through a plurality of insulating layers 3, thereby forming the double-sided copper block multi-layer circuit board 100 with a pressed stacked structure.
[0035] Among them, the inner side of the first base layer 11 of the outer heat dissipation core board 1 faces the circuit core board 2, while the outer side of the first base layer 11 faces away from the circuit core board 2. That is to say, the heat dissipation layer 13 of the outer heat dissipation core board 1 is arranged close to the circuit core board 2; at the same time, the multiple copper blocks 131 of the heat dissipation layer 13 are arranged opposite to the circuits of the circuit core board 2. That is to say, along the lamination direction of the double-sided copper block multi-layer circuit board 100, the copper blocks 131 are aligned with the circuits of the circuit core board 2, which is beneficial to the heat transfer of the copper blocks 131 and improves the heat dissipation effect. And the two outer heat dissipation core boards 1 are laminated with a plurality of circuit core boards 2 on opposite sides, and a plurality of copper blocks 131 can be embedded / buried at the same position in the lamination direction of the double-sided copper block multi-layer circuit board 100, so as to achieve double-sided current carrying.
[0036] The double-sided copper block multi-layer circuit board 100 of the embodiment of the present application adopts a lamination structure. Embedding the copper blocks 131 does not require an embedding process, avoiding matching problems caused by dimensional tolerances, reducing the precision requirements for controlling processing dimensional tolerances, and facilitating the control of the overall thickness of the circuit board, which is beneficial to reducing the overall thickness of the double-sided copper block multi-layer circuit board 100; a plurality of copper blocks 131 are arranged on the same plane, avoiding flatness problems of the circuit board caused by the thickness difference of the embedded copper blocks 131, and improving the flatness of the surface of the double-sided copper block multi-layer circuit board 100; the two outer heat dissipation core boards 1 can embed / bury a plurality of copper blocks 131 at the same position in the lamination direction of the double-sided copper block multi-layer circuit board 100, so as to achieve double-sided current carrying, meet the current-carrying requirements of the circuit board for simultaneously passing large currents on both sides, and is beneficial to realizing the best heat dissipation mode, effectively improving the heat dissipation efficiency of the double-sided copper block multi-layer circuit board 100.
[0037] In some embodiments, the shapes of the multiple copper blocks 131 of the heat dissipation layer 13 are the same as the shapes of the circuits of the adjacent circuit core board 2.
[0038] The shape of the multiple copper blocks 131 refers to the graphic shape formed by arranging the multiple copper blocks 131 on the surface of the first base layer 11; that is to say, the graphic shape formed by the multiple copper blocks 131 is the same as the graphic shape of the circuit diagram of the circuit core board 2. Among them, the shape of a single copper block 131 is consistent with the shape of the circuit of the circuit core board 2, that is, the width and length of the copper block 131 are the same as the width and length of the part of the circuit of the circuit core board 2 with which it is aligned. In some embodiments, the multiple copper blocks 131 of the heat dissipation layer 13 can be etched according to the required shape, such as the current direction (i.e., the circuit pattern).
[0039] In this way, the heat transfer efficiency of the copper blocks 131 can be improved, which is beneficial to further improving the heat dissipation effect.
[0040] In some embodiments, the heat dissipation layer 13 further includes copper bridges (not shown), and the multiple copper blocks 131 are connected by copper bridges.
[0041] The copper bridge refers to a copper component with a slender shape; the copper blocks 131 are connected by the slender copper bridge, which can fix the distance between the copper blocks 131. In this way, the relative positions of multiple copper blocks 131 are fixed, making the shape of the figure formed by multiple copper blocks 131 more stable, which is beneficial to improving the heat dissipation effect; moreover, multiple copper blocks 131 of the heat dissipation layer 13 can be obtained by etching a copper plate at the same time, which is beneficial to improving the processing efficiency and processing accuracy.
[0042] Of course, in other embodiments, multiple single copper blocks 131 can also be obtained by etching first, and then the reference position on the first base layer 11 is determined, and the position of the first copper block 131 is determined according to the relative position of the reference position; and since the distance between the copper blocks 131 is fixed, after the position of the first copper block 131 is determined, other copper blocks 131 can be arranged at equal intervals.
[0043] In some embodiments, the surfaces of the multiple copper blocks 131 facing away from the first base layer 11 are flush.
[0044] The surfaces of the multiple copper blocks 131 of the heat dissipation layer 13 attached to the surface of the insulating layer 3 are in the same plane. In this way, it is possible to further avoid the flatness problem of the heat dissipation layer 13 caused by the thickness difference of the multiple copper blocks 131, which is beneficial to further improving the flatness of the surface of the double-sided copper block multi-layer circuit board 100 and is beneficial to reducing the overall thickness of the double-sided copper block multi-layer circuit board 100.
[0045] In some embodiments, the thickness range of the copper block 131 is 300 microns to 800 microns.
[0046] The thickness of the copper block 131 refers to the dimension along the lamination direction of the double-sided copper block multi-layer circuit board 100. The thickness of the copper block 131 is greater than or equal to 300 microns and less than or equal to 800 microns, that is, the thickness of the copper block 131 is greater than or equal to 8OZ and less than or equal to 22OZ. In this way, it is beneficial to improve the heat dissipation performance of the outer heat dissipation core board 1.
[0047] In some embodiments, the first base layer 11 is a prepreg, a glass fiber cloth substrate or a composite substrate.
[0048] For example, the first base layer 11 can adopt a glass fiber cloth-based FR-4 board. FR-4 is a code for a flame-resistant material grade, which means a material specification in which the resin material must be able to extinguish itself after being in a combustion state; the FR-4 grade material used for the circuit board can be a composite material made of a tetra-functional (Tera-Function) epoxy resin plus a filler (Filler) and glass fiber. Glass fiber cloth-based FR-5 boards, composite base CEM-3 boards, etc. can also be adopted according to the actual situation.
[0049] In some embodiments, the outer circuit layer 12 is a copper layer.
[0050] The copper layer is formed with a circuit pattern. The copper layer can be a copper foil or can be formed on the outer side of the first base layer 11 by electroplating or other means, and there is no limitation here.
[0051] In some embodiments, the outer heat dissipation core board 1 includes copper blocks 131, prepregs, and copper foils that are press-bonded; the processing flow of the outer heat dissipation core board 1 includes the following steps: etching the copper plate according to the circuit pattern to obtain a heat dissipation layer 13 including a plurality of copper blocks 131; combining the heat dissipation layer 13, prepregs, and copper foils, and pressing them according to the stack structure to obtain the outer heat dissipation core board 1.
[0052] In some embodiments, the circuit core board 2 includes a second base layer 21 and inner circuit layers 22 respectively provided on opposite sides of the second base layer 21, and the inner circuit layers 22 are formed with circuit patterns.
[0053] The circuit core board 2 can be formed with circuit patterns on both sides. For example, the circuit core board 2 is a double-sided copper clad laminate that has completed the inner layer etching process, and the inner circuit layer 22 is the copper layer of the double-sided copper clad laminate that is formed with circuit patterns.
[0054] In some embodiments, the second base layer 21 is a prepreg, a glass fiber cloth substrate, or a composite substrate.
[0055] For example, the second base layer 21 can use a glass fiber cloth-based FR-4 board, and can also use a glass fiber cloth-based FR-5 board, a composite-based CEM-3 board, etc. according to actual situations. In some embodiments, the structure of the double-sided copper clad laminate is a stack of unetched copper foils, prepregs, and unetched copper foils.
[0056] In some embodiments, both the outer heat dissipation core board 1 and the circuit core board 2 are provided with positioning holes.
[0057] When pressing two outer heat dissipation core boards 1, a plurality of circuit core boards 2, and a plurality of insulating layers 3 according to the stack structure, the stack positions of the outer heat dissipation core board 1 and the circuit core board 2 are positioned through the positioning holes, so that the plurality of copper blocks 131 of the heat dissipation layer 13 are aligned with the circuits of the adjacent circuit core boards 2. In this way, it is beneficial to improve the processing accuracy of the double-sided copper block multilayer circuit board 100, ensure the heat transfer efficiency of the copper blocks 131, and improve the heat dissipation performance.
[0058] In some embodiments, the double-sided copper block multilayer circuit board 100 further includes electroplated through holes, and the electroplated through holes are electrically connected to the outer circuit layer 12 and the copper blocks 131 of the two outer heat dissipation core boards 1 and the circuits of the circuit core board 2.
[0059] By providing electroplated vias, the outer circuit layers 12 and copper blocks 131 of the two outer heat dissipation core boards 1 and the circuit conductive layers of the circuit core board 2 are electrically connected, which is beneficial to improving the heat dissipation efficiency of the double-sided copper block multilayer circuit board 100.
[0060] In some embodiments, the insulating layer 3 is a resin layer or a prepreg layer.
[0061] The insulating layer 3 can be a resin layer, such as a resin insulating film; the insulating layer 3 can also be a prepreg layer, such as a non-woven prepreg or an organic glass cloth prepreg. The two outer heat dissipation core boards 1 and at least two circuit core boards 2 are stacked through a plurality of insulating layers 3, and then under the action of a certain temperature and pressure, using the resin fluidity of the prepreg or the high thermal conductivity insulating material, when the temperature reaches a certain level, curing occurs, so that the outer heat dissipation core board 1 and at least two circuit core boards 2 are press-fitted and cured. Since the prepreg or other insulating resin materials have bonding properties and can melt and flow under high temperature and high pressure, smaller gaps between the circuit core board 2 and the copper blocks 131 of the outer heat dissipation core board 1 can be gradually filled during the press-fitting process, and after curing, the copper blocks 131 of the outer heat dissipation core board 1 and at least two circuit core boards 2 can be bonded into one body.
[0062] In some embodiments, the processing flow of the double-sided copper block multilayer circuit board 100 may include the following steps:
[0063] Cutting: The qualified copper clad laminate is cut into a predetermined size and shape, and then surface cleaning and drying are performed.
[0064] Inner circuit layer 22 graphic circuit transfer: A layer of photosensitive material is pasted on the copper layer of the copper clad laminate, and then alignment exposure is performed with a negative film graphic black film, so that the photosensitive material in the circuit area is cured during the exposure process, and the photosensitive material in the non-circuit area is not cured during the exposure process, completing the image transfer.
[0065] Inner layer etching: The undeveloped photosensitive material is dissolved with a developing solution to obtain a positive photosensitive material graphic film layer consistent with the size and shape of the predetermined inner layer graphic circuit, exposing the copper surface under the uncured photosensitive material, then etching away the non-circuit area copper layer exposed by inner layer etching, and then removing the cured photosensitive material with a stripping solution to expose the copper layer of the circuit part, forming the inner layer graphic circuit.
[0066] Inner layer circuit inspection: The inner layer graphic circuit of the inner circuit layer 22 is inspected through an optical detection device to ensure that there are no serious defects in the inner circuit layer 22.
[0067] Brownification: A brownification film layer is formed on the copper surface of the inner circuit layer 22. The brownification film layer is a molecule formed by the combination of organic molecules and copper atoms, further enhancing the bonding force between the copper surface of the inner circuit layer 22 and the prepreg, obtaining the circuit core board 2.
[0068] Press the plates according to the laminated structure: Stack the two pre - processed outer heat - dissipation core plates 1, multiple circuit core plates 2, and multiple insulating layers 3 according to the laminated structure of the double - sided copper - block multi - layer circuit board 100, and then vacuum - press them into an integral circuit board;
[0069] Cut the board edges and drill holes: Cut the process edges of the integral circuit board, and drill the required through - holes on the integral circuit board after pressing;
[0070] Copper deposition and board - surface electroplating: Deposit a copper layer between the conduction pattern layer and the pattern layer in the through - holes of the integral circuit board by chemical copper deposition method. The copper layer includes adjacent two or more pattern layers, making the through - holes become via holes; and electroplate the integral circuit board by full - board electroplating method to thicken the copper layers on the board surface and in the via holes of the integral circuit board;
[0071] Outer - layer dry film: Stick a photosensitive material on the outer - side copper foils of the two outer heat - dissipation core plates 1 on both sides, then perform alignment exposure with the outer - layer exposure film, and then develop to remove the unexposed part of the photosensitive material, obtaining a negative photosensitive material pattern film layer that matches the size and shape of the predetermined outer - layer circuit pattern;
[0072] Circuit electroplating and outer - layer etching: Place the integral circuit board in a pattern electroplating device for electroplating to thicken the copper layer of the pattern circuit and deposit tin on the surface of the copper layer of the pattern circuit as the anti - etching layer of the circuit, so as to protect the outer - layer circuit pattern from being penetrated by the etching solution during the outer - layer etching process, avoiding insufficient width of the pattern circuit and open - circuit defects; then perform outer - layer etching on the integral circuit board to form the outer - layer circuit pattern;
[0073] Outer - layer circuit inspection: Inspect the outer - layer circuit pattern through an optical detection device to ensure that there are no serious defects in the integral circuit board;
[0074] Solder mask ink: Screen - print solder mask ink and white characters on the integral circuit board;
[0075] Surface treatment: Perform surface treatment on the integral circuit board to prevent pad oxidation and facilitate pad soldering, such as immersion gold, immersion silver, immersion tin, tin spraying, OSP (oxidation prevention), and electroplating gold, etc.;
[0076] Routing: Route the integral circuit board with the completed surface treatment into finished unit boards according to customer requirements, and then clean them with a cleaning device, such as a horizontal or vertical cleaning machine;
[0077] Electrical testing: Detect the electrical performance of each layer of the integral circuit board;
[0078] Final inspection: Inspect the appearance of the finished unit boards that pass the electrical testing by using an appearance detection machine.
[0079] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.
[0080] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.
Claims
1. A double-sided copper block multi-layer circuit board, characterized in that, Comprising: Two outer heat dissipation core plates, the outer heat dissipation core plate includes a first base layer, an outer circuit layer provided on the outer side of the first base layer, and a heat dissipation layer provided on the inner side of the first base layer, the heat dissipation layer includes a plurality of copper blocks; At least two circuit core plates, stacked between the two outer heat dissipation core plates, at least one side of the circuit core plate is formed with a circuit, and the plurality of copper blocks of the heat dissipation layer are arranged opposite to the circuit of the adjacent circuit core plate; And A plurality of insulating layers are provided between the outer heat dissipation core plate and the circuit core plate, and between adjacent two circuit core plates. The two outer heat dissipation core plates and at least two circuit core plates are pressed together through the plurality of insulating layers.
2. The double-sided copper block multi-layer circuit board according to claim 1, wherein The shapes of the plurality of copper blocks of the heat dissipation layer are the same as the shapes of the circuits of the adjacent circuit core plates.
3. The double-sided copper block multi-layer circuit board according to claim 1, characterized in that The heat dissipation layer further includes copper bridges, and the plurality of copper blocks are connected by the copper bridges.
4. The double-sided copper block multi-layer circuit board according to claim 1, wherein, The surfaces of the plurality of copper blocks facing away from the first base layer are flush.
5. The double-sided copper block multi-layer circuit board according to claim 1, characterized in that, The thickness range of the copper blocks is 300 microns to 800 microns.
6. The double-sided copper block multi-layer circuit board according to claim 1, wherein The first base layer is a semi-cured sheet, a glass fiber cloth substrate or a composite substrate; and / or, the outer circuit layer is a copper layer.
7. The double-sided copper block multi-layer circuit board according to claim 1, wherein The circuit core plate includes a second base layer and inner circuit layers respectively provided on opposite sides of the second base layer, and the inner circuit layers are formed with the circuit patterns.
8. The double-sided copper block multi-layer circuit board according to claim 1, wherein The outer heat dissipation core plate and the circuit core plate are both provided with positioning holes.
9. The double-sided copper block multi-layer circuit board according to claim 1, wherein The double-sided copper block multi-layer circuit board further includes electroplated through holes, and the electroplated through holes are electrically connected to the outer circuit layers and the copper blocks of the two outer heat dissipation core plates and the circuits of the circuit core plates.
10. The double-sided copper block multi-layer circuit board according to any one of claims 1 to 9, characterized in that, The insulating layer is a resin layer or a semi-cured sheet layer.