Thermoelectric separation circuit board manufacturing method and circuit board

Abstract

The invention discloses a thermoelectric separation circuit board manufacturing method and a circuit board, and belongs to the field of circuit boards, the manufacturing method utilizes a pattern electroplating mode to manufacture a circuit board boss based on the idea of an addition process, and comprises the following steps: laminating a metal substrate, heat-conducting glue and a copper foil, and etching a dielectric layer corresponding to the boss position by utilizing a chemical method, forming a medium-free recess; performing electroplating filling on the medium-free recess by adopting a pattern electroplating method to obtain a boss flush with the surface of the laminated plate; the height of the boss is convenient to control by adopting an electroplating filling mode, and the flatness of a product can be ensured; by adopting the method, the problems that the flatness of the boss and the press fit surface is poor and the manufacturing efficiency is low can be effectively avoided, the filling and leveling effect is ensured by adopting an electroplating mode, the manufacturing reliability and efficiency are improved, the cost is reduced, and large-batch production is facilitated; the method gives consideration to both the heat dissipation effect and the quality of the product, is simple in principle and convenient to implement, and has good popularization and application values.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit boards, and in particular relates to a method for manufacturing a thermoelectric separation circuit board and a circuit board. Background Art

[0002] For LED light emission, in the process of converting electrical energy into light energy, about 70% of the electrical energy is converted into heat energy, and the electro-optical efficiency is low. Moreover, as the working time increases, the heat energy gradually accumulates, the working environment temperature increases, and the light flux will gradually decay, causing its life to decrease. In order to improve its heat dissipation, metal substrates and thermoelectric separation copper substrates have been developed, especially copper substrates with thermoelectric separation structures, which can achieve local non-insulating dielectric layers. The heating parts of the components are directly welded on the bosses formed by the heat dissipation substrate, which greatly improves the thermal conductivity, minimizes the interface thermal resistance, and reduces the temperature accumulation, which can greatly extend the life of electronic products.

[0003] The current thermoelectric separation process is based on traditional mechanical methods, mainly using a controlled deep copper etching mechanical method, first drilling the dielectric layer and surface substrate or copper foil at the hollow boss position, and then pressing. During the pressing process, due to the residual dust from the mechanical drilling, bubbling and bulging are easy to occur. The height difference of the copper etching on the boss is different from the thickness of the total dielectric layer, resulting in a height difference of the boss. After pressing, multiple grinding is required to reduce the height difference so that the boss and the pressed surface are as flat as possible. Therefore, the reliability of the above method is not high. Even if the boss is lower than the pressed surface, it will cause a depression, resulting in the risk of product scrapping. In addition, the above-mentioned controlled deep copper etching method will lead to serious waste of materials due to the etching of copper. Overall, the cost is relatively high, which is not conducive to mass production and large-scale application of this category.

[0004] It can be seen that the existing thermoelectric separation process, due to the method of hollowing out first and then pressing, leads to poor flatness of the boss and the pressed surface and low production efficiency. Summary of the invention

[0005] The present invention provides a method for manufacturing a thermoelectric separation circuit board and a circuit board to solve the technical problems of the existing thermoelectric separation process, which adopts the method of hollowing out first and then pressing, resulting in poor flatness of the boss and the pressing surface and low manufacturing efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical contents:

[0007] A method for manufacturing a thermoelectric separation circuit board comprises the following steps:

[0008] S1: The copper surface of the metal substrate and the copper foil are pressed together using a thermal conductive adhesive to obtain a pressed board;

[0009] S2: Cutting, drilling, first pattern transfer and etching are performed on the laminate in sequence; the dielectric layer corresponding to the preset boss position is etched away by a chemical method to form a dielectric-free recess, and the dielectric layer at the edges around the top of the metal substrate is etched away to obtain the laminate to be electroplated;

[0010] S3: sequentially performing sandblasting and a second pattern transfer process on the pressed plate to be electroplated; electroplating and filling the non-medium depressions using a pattern electroplating method to form a boss flush with the surface of the pressed plate to be electroplated, thereby obtaining a semi-finished thermoelectric separation circuit board;

[0011] S4: Processing the semi-finished product of the thermoelectric separation circuit board to obtain a finished product of the thermoelectric separation circuit board.

[0012] Furthermore, in S3, the specific steps of using the pattern electroplating method to electroplating and fill the non-medium recess are as follows:

[0013] dividing the total electroplating time equally into a first electroplating time and a second electroplating time;

[0014] The electroplating clamp is clamped on the first electroplating clamping edge of the top four edges of the metal substrate of the pressed plate to be electroplated, and the first pattern electroplating is performed and lasts for a first electroplating time;

[0015] The electroplating clamp is on a second electroplating clamping edge around the edges of the top of the metal substrate of the pressed plate to be electroplated, and a second pattern electroplating is performed for a second electroplating time, wherein the first electroplating clamping edge and the second electroplating clamping edge are arranged opposite to each other.

[0016] Furthermore, the total electroplating time is calculated based on the copper plating rate of the copper plating brightener, the current density, and the electroplating area.

[0017] Furthermore, after the first pattern electroplating, the leveling effects of the high, medium and low potentials are measured, and the second electroplating time is adjusted based on the medium potential.

[0018] Furthermore, in S1, the metal substrate is made of a copper-aluminum composite material; wherein the copper surface thickness is 17-200 μm.

[0019] Furthermore, in S1, before the copper surface of the metal substrate and the copper foil are pressed together using the thermal conductive adhesive, the copper surface is subjected to browning treatment.

[0020] Furthermore, in S1, the thermal conductive adhesive uses PP adhesive made of pure adhesive.

[0021] Furthermore, in S2, a chemical method is used to etch away the dielectric layer corresponding to the preset boss position to form a dielectric-free recess, and the chemical reagent used is 92%-98% concentrated sulfuric acid.

[0022] Furthermore, in S4, the specific steps of processing the semi-finished product of the thermoelectric separation circuit board include:

[0023] The semi-finished products of the thermoelectric separation circuit board are sequentially subjected to film stripping, third pattern transfer, etching, solder mask text, molding, cleaning, testing, outer tube inspection and packaging.

[0024] A thermoelectric separation circuit board is manufactured by adopting the thermoelectric separation circuit board manufacturing method.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The invention provides a method for manufacturing a thermoelectric separation circuit board. The method uses a graphic electroplating method to manufacture a circuit board boss based on the idea of ​​an additive method, including laminating a metal substrate with a thermal conductive adhesive and a copper foil, and etching away a dielectric layer corresponding to the boss position by a chemical method to form a dielectric-free depression; the dielectric-free depression is electroplated and filled by a graphic electroplating method to obtain a boss flush with the surface of a pressed plate; the electroplating filling method is convenient for controlling the height of the boss and can ensure the flatness of the product; the method can effectively avoid the problem of poor flatness between the boss and the pressed surface and low manufacturing efficiency, the electroplating method is used to ensure the filling effect, and the reliability and efficiency of the manufacturing are improved, the cost is reduced, and it is conducive to mass production; the method takes into account the heat dissipation effect and product quality of the product, the principle is simple and easy to implement, and has good promotion and application value.

[0027] Preferably, in the present invention, the electroplating filling is divided into two pattern electroplatings, and the two electroplatings are performed in reverse order to balance the filling effect of high and low potentials, which is beneficial to reduce the impact of the high and low potential difference on surface flatness.

[0028] Further preferably, in the present invention, the total electroplating time can be accurately calculated according to the copper coating rate of the copper plating brightener, the current density, and the electroplating area, thereby ensuring the controllability and accuracy of the electroplating process and further improving the filling quality of the boss.

[0029] Further preferably, in the present invention, after the first graphic electroplating, the filling effect of high, medium and low potentials is measured, and the second electroplating time is adjusted based on the medium potential, thereby achieving fine control of the electroplating process and ensuring the uniformity and consistency of the boss filling.

[0030] Preferably, in the present invention, the metal substrate adopts a copper-aluminum composite metal substrate made of a copper-aluminum composite material. Under the premise of ensuring a good heat dissipation effect, a high heat dissipation metal substrate of a thermoelectric separation structure is made of a copper-aluminum composite material with an extremely thin copper ratio, which can greatly save copper materials and thus greatly reduce the product manufacturing cost.

[0031] Preferably, in the present invention, the copper surface of the metal substrate is browned before lamination, thereby enhancing the bonding force between the thermally conductive adhesive and the copper surface of the metal substrate and improving the stability and reliability of the lamination plate.

[0032] Preferably, in the present invention, PP glue made of pure glue is used as the thermally conductive glue, which has excellent thermal conductivity and bonding properties, ensures the close bonding between the copper surface of the metal substrate and the copper foil, and improves the overall performance of the circuit board; at the same time, since the thermally conductive glue of the dielectric layer needs to be etched away, the use of pure glue can ensure the corrosion effect, thereby providing favorable operation guarantees for subsequent process flows.

[0033] Preferably, in the present invention, 92%-98% concentrated sulfuric acid is used as a chemical reagent to etch away the dielectric layer, preferably 95% concentrated sulfuric acid. Compared with the traditional controlled deep copper etching mechanical method, it has the advantages of fast etching speed, good effect, and little damage to the metal substrate, and can effectively improve the efficiency and accuracy of etching.

[0034] Preferably, in the present invention, the subsequent processing steps include film stripping, third pattern transfer according to product requirements, etching, solder mask text, molding, cleaning, testing, outer tube inspection and packaging, etc., to ensure the quality and reliability of the finished circuit board.

[0035] The present invention also provides a thermoelectric separation circuit board, which is manufactured by the above-mentioned manufacturing method. Since the boss is manufactured by electroplating and filling, the thermoelectric separation circuit board has good product flatness, takes into account good heat dissipation performance and product quality, and meets the application requirements of thermoelectric separation. The thermoelectric separation circuit board has excellent thermal conductivity, flat bosses, stable structure and reliable performance, and is suitable for various application scenarios requiring thermoelectric separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flowchart of a method for manufacturing a thermal-electric separation circuit board provided by an embodiment of the present invention;

[0037] Figure 2 A cross-sectional view of a product structure manufactured by applying the method for manufacturing a thermoelectric separation circuit board provided by an embodiment of the present invention;

[0038] Figure 3 A top view of a product manufactured by applying the method for manufacturing a thermoelectric separation circuit board provided by an embodiment of the present invention;

[0039] Figure 4 for Figure 3 A partial view of the .

[0040] Reference numerals:

[0041] 1-metal substrate; 1-1-copper surface; 1-2-aluminum plate; 2-thermal conductive adhesive; 3-copper foil; 4-boss; 5-first electroplating clamping edge; 6-second electroplating clamping edge. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does 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 the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0047] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Example 1

[0050] As mentioned in the background technology, the current thermal and electrical separation process mainly relies on traditional mechanical methods, especially the mechanical method of controlling deep copper etching. This method faces multiple challenges in actual operation. First, the residual dust generated during the mechanical drilling process is a problem that cannot be ignored. These dusts not only pollute the production environment, but also easily cause blistering and bulging during the pressing process, which seriously affects the flatness and quality stability of the product. In addition, due to the precision limitation of mechanical processing, the height difference of the copper etching of the boss is often difficult to accurately control, and there is often a significant difference between the total dielectric layer thickness, resulting in the boss forming a surface of different heights after pressing, which further increases the difficulty and cost of subsequent grinding and finishing. The height difference between the boss and the pressed surface not only affects the appearance of the product, but is also directly related to its thermal and electrical conductivity. In order to reduce this height difference and ensure the flatness of the boss and the pressed surface, manufacturers have to perform multiple grinding processes. However, the grinding process is not only time-consuming and labor-intensive, but may also cause unnecessary damage to the circuit board, reducing its overall performance. What is more serious is that if the boss is excessively worn during the pressing process, or even lower than the pressing surface, it will cause the product to be dented, directly leading to the risk of scrapping and causing huge losses to production. The controlled depth copper etching method will inevitably waste a lot of materials during the copper etching process. This not only increases production costs, but also creates an unnecessary burden on the environment. In today's increasingly tight resources, this waste phenomenon is obviously not in line with the requirements of sustainable development. In addition, the high cost also limits the competitiveness of this process in mass production and wide application. While pursuing profit maximization, manufacturers have to consider how to reduce costs and improve production efficiency while ensuring product quality.

[0051] In order to solve the above problems, the present invention provides a method for manufacturing a thermoelectric separation circuit board. The method provides a new thermoelectric separation technology, which combines thermal conductive adhesive lamination, chemical etching and graphic electroplating, and can take into account both the heat dissipation performance of the product and good product quality. It can not only solve the various drawbacks of traditional processes, but also bring greater market competitiveness and profit margins.

[0052] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0053] like Figure 1 As shown, this embodiment provides a method for manufacturing a thermal-electric separation circuit board, combining Figure 2 As shown, the specific steps are as follows:

[0054] The first step: the copper surface 1-1 of the metal substrate 1 is pressed together with the copper foil 3 by using the thermal conductive adhesive 2 to obtain a pressed board.

[0055] In this embodiment, in order to ensure good bonding strength and lamination effect, the copper surface 1-1 needs to be machine-brownized in advance. After the browning treatment, 100μm of thermal conductive adhesive 2 and 1oz of copper foil 3 are overlapped on the copper surface 1-1 for lamination. The lamination program is set according to the specification of the thermal conductive adhesive 2. After the lamination is completed, a laminated plate is obtained.

[0056] Step 2: Cut, drill, transfer the first pattern and etch the laminate in sequence; chemically etch away the dielectric layer corresponding to the position of the preset boss 4 to form a dielectric-free recess, and etch away the dielectric layer around the edge of the top of the metal substrate 1 to obtain the laminate to be electroplated.

[0057] In this embodiment, the laminate is cut according to the design requirements of the product to obtain the required specifications, a reference hole is drilled on the laminate, and the first pattern transfer is performed; in this step, the pattern of the first pattern transfer is the surface shape of the boss position, and the positive film alkaline etching process is used. After the target photosensitive film is developed, the other places (the surrounding copper foil of the boss position) are protected by a film, and the copper foil corresponding to the boss position is exposed here, and the copper chloride etching solution is used for etching. After the etching is completed, the thermal conductive adhesive 2 to be bitten by sulfuric acid corresponding to the boss position is exposed. The first pattern positive film shows that the surface pattern of the boss and the surrounding electroplated clamping edges are black, and black is opaque. The photosensitive film does not absorb energy and does not undergo polymerization reaction, and will be dissolved by a 1% sodium carbonate dilute alkali solution. Finally, the exposed copper foil is etched away to expose the dielectric layer to be removed, that is, the thermal conductive adhesive 2.

[0058] It can be seen that the function of the first pattern transfer is to etch away the copper foil corresponding to the boss position and the copper foil corresponding to the surrounding electroplating clamping edges, thereby exposing the thermal conductive adhesive 2 to be corroded by sulfuric acid.

[0059] A chemical method is used to etch away the dielectric layer corresponding to the preset boss 4 position and the dielectric layer at the edges around the top of the metal substrate 1; in this step, it is mainly a degumming process, and a chemical reagent of 92%-98% concentrated sulfuric acid, preferably 95% concentrated sulfuric acid, is used to corrode the above-mentioned parts, thereby obtaining a dielectric-free depression in the dielectric layer corresponding to the boss 4 position, and obtaining a pressed plate to be electroplated.

[0060] Step 3: The plate to be plated is subjected to sandblasting and a second pattern transfer process in sequence; the non-medium depressions are plated and filled using a pattern electroplating method to form a boss 4 flush with the surface of the plate to be plated, thereby obtaining a semi-finished thermoelectric separation circuit board.

[0061] In this step, the pattern of the second pattern transfer is the same as the first pattern. The purpose is to cover the anti-plating film on the boss and the parts other than the eroded thermal conductive adhesive around before using the positive film acid plating solution for filling and leveling electroplating, to ensure that the surface copper foil will not be plated with a copper layer higher than the pressed copper. Similarly, the second pattern transfer is also a positive film, the surface pattern of the boss and the electroplated clamping edge around are black, black is opaque, the photosensitive film does not absorb energy, and does not undergo polymerization reaction, and will be dissolved by 1% sodium carbonate dilute alkali solution; the exposed copper will accumulate level during electroplating, that is, the copper surface on the metal substrate will be exposed after the thermal conductive adhesive is removed, and the copper surface is electroplated and leveled by electroplating.

[0062] It can be seen that the role of the second pattern transfer is to facilitate the electroplating filling of the boss position and prevent the copper foil at other positions except the boss from being electroplated.

[0063] In this embodiment, in order to ensure the effect of electroplating, in this embodiment, the anti-electroplating treatments such as sandblasting and second pattern transfer are sequentially performed on the pressed plate to be electroplated; then the non-medium depression is electroplated and filled by using the pattern electroplating method. In this embodiment, the gantry electroplating process is adopted to complete the batch electroplating operation. The specific steps are as follows:

[0064] S201, dividing the total electroplating time equally into a first electroplating time and a second electroplating time.

[0065] In this embodiment, the total electroplating time is calculated based on the copper plating rate of the copper plating brightener, the current density, and the electroplating area. The specific calculation is as follows:

[0066] V represents the copper plating rate of the copper plating brightener, usually in micrometers / ampere hours (μm / A·h). This parameter represents the thickness of the coating increased per unit time under a given current;

[0067] I represents the current used in electroplating, in amperes (A);

[0068] A represents the electroplating area, in square meters (m 2 ). Note that the area here refers to the copper surface area actually involved in electroplating;

[0069] T represents the required electroplating time, in hours (h);

[0070] d represents the target coating thickness in micrometers (μm).

[0071] Since electroplating is carried out uniformly under ideal conditions, the coating thickness is proportional to the current density (i.e. current divided by area) and the electroplating time. Therefore, we have:

[0072]

[0073] Right now:

[0074] S202, the electroplating anode is clamped on the first electroplating clamping edge 5 around the top edge of the metal substrate 1 of the pressed plate to be electroplated, and the cathode is located in the dielectric-free recess, and the first pattern electroplating is performed and lasts for a first electroplating time;

[0075] S203, the electroplating clamp is clamped on the second electroplating clamping edge 6 around the top edges of the copper surface 1-1 of the pressed plate to be electroplated, and a second pattern electroplating is performed for a second electroplating time, wherein the first electroplating clamping edge 5 and the second electroplating clamping edge 6 are arranged opposite to each other.

[0076] In this embodiment, the leveling effect of high and low potentials is balanced by the reverse electroplating method, which is helpful to reduce the impact of the high and low potential difference on the surface flatness.

[0077] In this embodiment, after the first pattern electroplating, by measuring the filling effect of high, medium and low potentials, and adjusting the second electroplating time based on the medium potential, the electroplating process is finely controlled to ensure the uniformity and consistency of the filling of the boss 4. In this embodiment, after the first part is plated, the filling effect of high, medium and low potentials is sliced ​​or measured to confirm, and the remaining electroplating time (second electroplating time) is determined based on the medium potential to determine whether it needs to be adjusted, and the metal substrate is turned around and plated again to balance the filling effect of high and low potentials. According to the copper coating rate of about 0.5μm / minute, the final filling effect can be + / -10μm.

[0078] Step 4: Process the semi-finished product of the thermoelectric separation circuit board to obtain a finished product of the thermoelectric separation circuit board.

[0079] In this embodiment, it specifically includes film stripping, third pattern transfer, etching, solder mask text, molding, cleaning, testing, outer tube inspection and packaging processing; among which, the third pattern transfer is carried out according to product requirements.

[0080] In this step, the third pattern transfer is performed according to product requirements, that is, customer requirements, and specifically includes the copper foil network of the electroplated flattened bosses and other pressed copper areas.

[0081] like Figure 2 and Figure 3 As shown, this embodiment also provides a thermoelectric separation circuit board, which is manufactured by the above-mentioned thermoelectric separation circuit board manufacturing method, as shown in FIG. Figure 3 As shown, Figure 3 This is a surface view of the manufactured thermoelectric separation circuit board. The entire circuit board has a number of boss 4 structures, and the red one is the surface copper foil circuit; Figure 4 As shown, Figure 4 for Figure 3 A local enlarged picture, where the blue part is the thermoelectric separation boss area, and the purple part is a part of the blue, which is the LED component chassis, using a direct contact method; it can be seen that the copper layer from the metal substrate is electroplated to the copper foil layer of the surface routing, and the electroplating thickness is the sum of the dielectric layer thickness and the surface copper foil thickness.

[0082] It can be seen that the present embodiment provides a method for manufacturing a thermoelectric separation circuit board. The thermoelectric separation circuit board manufacturing technology is rooted in the essence of the additive method and cleverly uses graphic electroplating technology to construct a boss structure on the circuit board. The process begins with the precise pressing of the copper surface of the metal substrate and the copper foil. Subsequently, the dielectric layer of the preset boss area is accurately removed through precise chemical etching technology to create a dielectric-free recessed area. Using graphic electroplating technology, these recesses are accurately electroplated and filled until their surface is perfectly flush with the surrounding press plates to form the required boss structure. The electroplating filling strategy not only gives high controllability to the boss height, but also greatly guarantees the overall flatness of the product. Compared with traditional mechanical processing methods, this method effectively avoids the problem of uneven height caused by dust pollution and eliminates the cumbersome multiple grinding steps, thereby significantly improving production efficiency and reducing costs while ensuring the filling quality, paving the way for large-scale production. It is particularly worth mentioning that this production method not only improves the production efficiency and cost-effectiveness of the thermoelectric separation circuit board, but also takes into account the heat dissipation performance and quality of the product, achieving a win-win situation of functionality and economy. The principle of the method is intuitive and easy to understand, and the operation is simple. It has opened up a new efficient and reliable path for the production of thermoelectric separation circuit boards, showing broad application prospects and promotion value.

[0083] Example 2

[0084] This embodiment also provides another method for manufacturing a thermoelectric separation circuit board and a circuit board. The manufacturing method of this embodiment is basically the same as the basic steps and the manufactured circuit board of embodiment 1, except that the manufacturing method of this embodiment is further optimized and improved on the basis of embodiment 1. Figure 2 As shown, the details are as follows:

[0085] In the manufacturing method provided in this embodiment, the metal substrate 1 is made of a copper-aluminum composite material, and a layer of copper surface (1-1) is pressed on the aluminum plate 1-2. The thickness of the copper surface can be adjusted according to product requirements. In this embodiment, the thickness is 17-200μm, and 35μm is preferably selected, that is, the proportion of copper is about 10% of the overall composite board. This takes into account both the cost and ensures a good heat dissipation effect, and has a good market application prospect.

[0086] In addition, in this embodiment, during the lamination process, the thermally conductive adhesive 2 used is pure PP adhesive, and the thickness of the pure adhesive is usually 50-200um. In this embodiment, the preferred thickness is 75-125um. The use of pure adhesive ensures the bonding strength on the one hand; more importantly, the lamination plates after lamination need to be debonded, and the use of pure adhesive facilitates the debonding work, which provides a good guarantee for further follow-up work, thereby ensuring the production yield of the product.

[0087] This embodiment provides another method for manufacturing a thermoelectric separation circuit board and a circuit board. The key points of this technical solution are as follows:

[0088] First, use copper-aluminum composite materials with extremely thin copper to make heat dissipation PCB with thermoelectric separation structure;

[0089] Second, the dielectric layer uses pure glue without glass fiber, and the method of removing the dielectric layer is a non-mechanical and energy-based chemical method.

[0090] Third, the method of making the boss is not the traditional controlled deep etching, but the electroplating additive method.

[0091] Fourth, during electroplating, the electroplating clamping edge and the depression to be plated are the same conductive layer.

[0092] Fifth, the two electroplating processes are reversed and measurement is performed in between, which helps to reduce the surface flatness caused by the high and low potential differences.

[0093] It can be seen that the method for manufacturing a thermoelectric separation circuit board provided in this embodiment has the following advantages: First, a high-heat dissipation metal substrate of a thermoelectric separation structure is manufactured using a copper-aluminum composite material with an extremely thin copper ratio. The traditional controlled deep etching copper process can basically only use pure copper for production. Therefore, the use of this method can greatly save copper materials and ensure the same heat dissipation effect.

[0094] Second, the conventional controlled deep etching of copper uses a mechanical drill to remove the dielectric layer, while this embodiment uses chemical agents, mainly 95% concentrated sulfuric acid, to etch away the dielectric around the local area and the board. When etching away the local dielectric, other areas are protected by copper and aluminum, so the dielectric will not be damaged, and it is suitable for mass production;

[0095] Third, after removing copper and dielectrics locally and all around, copper is electroplated and deposited using an additive method in the form of graphic electroplating to fill the plain, dielectric-free depressions. During electroplating, the opposite edges of the metal substrate are clamped in sequence.

[0096] Fourth, calculate the electroplating time according to the copper coating rate, current density, and electroplating area of ​​the copper plating brightener, and divide the electroplating time into two equal parts. After plating the first part, slice or measure the leveling effect of the high, medium, and low potentials, and use the medium potential as the benchmark to determine whether the remaining electroplating time needs to be adjusted. Turn the metal substrate around and plate it again to balance the leveling effect of the high and low potentials. Based on the copper coating rate of approximately 0.5um / minute, the final leveling effect can be + / -10um.

[0097] Fifth, the production method that combines chemical etching with graphic electroplating adopts the idea of ​​additive method. It has good versatility, is not limited by mechanical processing, and can produce surface bosses of any complexity.

[0098] In summary, the present invention provides a method for manufacturing a thermoelectric separation circuit board, which has the following advantages over the existing thermoelectric separation process:

[0099] The method is adopted to achieve efficient thermal and electrical separation and high-quality production of circuit boards. Specifically, the method closely combines the metal substrate and the copper foil through thermal conductive adhesive to ensure good thermal conductivity; through cutting, drilling, pattern transfer and etching, the basic structure of the circuit board is formed, and a non-medium recessed area is specially designed for subsequent electroplating filling, which enhances the thermal and electrical separation effect of the circuit board. In the electroplating filling process, the graphic electroplating method is adopted and carried out twice, combined with the measurement and adjustment of the potential filling effect, to ensure that the boss is perfectly flush with the surface of the circuit board, and further improve the flatness and performance stability of the circuit board. In addition, the metal substrate made of copper-aluminum composite material and high-quality materials such as pure glue PP thermal conductive adhesive are used to enhance the thermal conductivity and structural strength of the circuit board. Finally, through meticulous semi-finished product processing, including film stripping, pattern transfer, etching, solder mask text and other links, the high quality and reliability of the thermal and electrical separation circuit board are ensured. In general, the adoption of this method not only improves the production efficiency of the thermal and electrical separation circuit board, but also significantly improves the thermoelectric performance, structural strength and overall quality of the product, providing strong support for the application in the field of circuit board technology.

[0100] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A method for manufacturing a thermoelectric separation circuit board, characterized in that: The steps include: S1: using a thermally conductive adhesive (2) to press the copper surface (1-1) of the metal substrate (1) and the copper foil (3) to obtain a pressed plate; S2: Cutting, drilling, first pattern transfer and etching are performed on the laminate in sequence; the dielectric layer corresponding to the position of the preset boss (4) is etched away by a chemical method to form a dielectric-free recess, and the dielectric layer around the edges of the top of the metal substrate (1) is etched away to obtain a laminate to be electroplated; S3: sequentially subjecting the plate to be plated to sandblasting and second pattern transfer processing; using a pattern electroplating method to electroplating and fill the non-medium depressions to form a boss (4) flush with the surface of the plate to be plated, thereby obtaining a semi-finished thermoelectric separation circuit board; S4: Processing the semi-finished product of the thermoelectric separation circuit board to obtain a finished product of the thermoelectric separation circuit board.

2. A method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S3, the specific steps of using the pattern electroplating method to electroplating and fill the non-medium recess are as follows: dividing the total electroplating time equally into a first electroplating time and a second electroplating time; The electroplating clamp is clamped on a first electroplating clamping edge (5) on the four edges of the top of the metal substrate (1) of the pressed plate to be electroplated, and the first pattern electroplating is performed and lasts for a first electroplating time; The electroplating clamp is clamped on a second electroplating clamping edge (6) on the edges of the top of the metal substrate (1) of the pressed plate to be electroplated, and a second pattern electroplating is performed for a second electroplating time, wherein the first electroplating clamping edge (5) and the second electroplating clamping edge (6) are arranged opposite to each other.

3. A method for manufacturing a thermoelectric separation circuit board according to claim 2, characterized in that: The total electroplating time is calculated based on the copper plating rate of the copper plating brightener, the current density, and the electroplating area.

4. A method for manufacturing a thermoelectric separation circuit board according to claim 2, characterized in that: After the first pattern electroplating, the leveling effect of high, medium and low potentials is measured, and the second electroplating time is adjusted based on the medium potential.

5. The method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S1, the metal substrate (1) is made of a copper-aluminum composite material; wherein the copper surface (1-1) has a thickness of 17-200 μm.

6. The method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S1, before the copper surface (1-1) of the metal substrate (1) and the copper foil (3) are pressed together using the thermal conductive adhesive (2), the copper surface (1-1) is subjected to a browning treatment.

7. The method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S1, the thermal conductive adhesive (2) is PP adhesive made of pure adhesive.

8. The method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S2, a chemical method is used to etch away the dielectric layer corresponding to the position of the preset boss (4) to form a dielectric-free recess, and the chemical reagent used is 92%-98% concentrated sulfuric acid.

9. The method for manufacturing a thermoelectric separation circuit board according to claim 1, characterized in that: In S4, the specific steps of processing the semi-finished product of the thermoelectric separation circuit board include: The semi-finished products of the thermoelectric separation circuit board are sequentially subjected to film stripping, third pattern transfer, etching, solder mask text, molding, cleaning, testing, outer tube inspection and packaging.

10. A thermoelectric separation circuit board, characterized in that: The thermoelectric separation circuit board is manufactured by the manufacturing method of any one of claims 1 to 9.

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