Copper-based circuit board manufacturing method and copper-based circuit board

Abstract

The present invention discloses a method for manufacturing a copper-based circuit board and a copper-based circuit board. The method comprises the following steps: attaching a dry film layer to the surface of a copper substrate and opening a window in the dry film layer; etching a groove on the copper substrate at the position of the window pattern by etching; removing the dry film layer; forming a circuit pattern on the copper layer of the circuit layer of the copper-clad board, and forming a surface pattern corresponding to the circuit pattern on the surface copper layer of the copper-clad board; placing a second dielectric layer between the copper substrate and the copper-clad board, pressing the copper substrate and the copper-clad board together, pressing the circuit pattern into the groove, pressing the first dielectric layer and the second dielectric layer together to form a dielectric layer, and pressing the surface pattern into the dielectric layer; etching away the surface pattern; removing the dielectric layer on the surface of the copper substrate by polishing; and forming a protective layer on the surface of the copper substrate to obtain the copper-based circuit board. The present invention has low production cost, is simple and efficient, and improves the reliability of the copper-based circuit board.

Description

Technical Field

[0001] The present invention relates to the field of circuit board manufacturing, and in particular to a copper-based circuit board manufacturing method and a copper-based circuit board. Background Art

[0002] For certain PCB products that support high current flux or extremely high heat dissipation requirements, a thicker copper substrate is required. The current general copper-based PCB manufacturing method is to add a dielectric layer to the surface of the copper substrate, create a circuit pattern on the dielectric layer, and then cover the circuit pattern with a protective layer.

[0003] The existing production method has the following disadvantages:

[0004] (1) Since the circuit board needs to support high current and high heat dissipation application scenarios, the dielectric layer added to the surface of the copper substrate requires a high bonding strength with the copper base, which leads to high production requirements, thereby increasing the production cost. If slight delamination occurs, it will cause more serious consequences during the application process.

[0005] (2) For some application modules that have higher thickness restrictions on circuit boards, the circuit pattern is required not to be higher than the surface of the copper substrate. Therefore, the current approach is difficult to meet such requirements.

[0006] (3) Since the circuit pattern is located above the copper substrate and there is a thick dielectric layer between the circuit pattern and the copper substrate, the heat dissipation efficiency of the copper substrate cannot be effectively exerted.

[0007] Based on the above problems, it is necessary to provide a new copper-based circuit board manufacturing method to meet the circuit board requirements of high current and high heat dissipation application modules. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for manufacturing a copper-based circuit board and a copper-based circuit board. By etching a groove body in a copper substrate and pressing a circuit pattern into the groove body, the circuit pattern is ensured to be no higher than the copper substrate, thereby improving the reliability of the copper-based circuit board and meeting the circuit board requirements of high-current, high-heat dissipation application modules.

[0009] In a first aspect, the present invention provides a method for manufacturing a copper-based circuit board, wherein the copper-based circuit board includes a copper substrate and a copper-clad laminate, wherein the copper-clad laminate includes a surface copper layer, a first dielectric layer, and a circuit layer copper layer laminated from top to bottom, and the manufacturing method includes the following steps:

[0010] A dry film layer is attached to the surface of the copper substrate, and windows are opened in the dry film layer, wherein the pattern of the window opening is the same as the pattern of the groove body to be subsequently etched;

[0011] Etching a groove on the copper substrate at the position of the window pattern by etching;

[0012] removing the dry film layer to obtain a copper substrate having a trough body;

[0013] A circuit pattern is formed on the copper layer of the circuit layer of the copper clad laminate, and a surface pattern corresponding to the circuit pattern is formed on the surface copper layer of the copper clad laminate, wherein the area of the surface pattern is larger than the notch area of the notch body, thereby obtaining a copper clad laminate having a circuit pattern;

[0014] A second dielectric layer is placed between a copper substrate having a slot body and a copper-clad laminate having a circuit pattern. The copper substrate having a slot body and the copper-clad laminate having a circuit pattern are pressed together, and the circuit pattern is pressed into the slot body. The first dielectric layer and the second dielectric layer are pressed together to form a dielectric layer. The dielectric layer is located on the surface of the copper substrate and inside the slot body, and the surface pattern is pressed into the dielectric layer.

[0015] etching away the surface pattern by etching;

[0016] removing the dielectric layer on the surface of the copper substrate by polishing;

[0017] A protective layer is formed on the surface of the copper substrate to obtain a copper-based circuit board.

[0018] Furthermore, the thickness of the copper substrate is 2 to 5 mm.

[0019] Furthermore, the groove body has a depth of 1 to 3 mm, and is formed by etching multiple times, with the depth of each etching being 1 / 5 to 1 / 3 of the groove body depth.

[0020] Furthermore, the thickness of the first dielectric layer of the copper clad laminate is the same as the depth of the slot.

[0021] Furthermore, a single side of the surface pattern is 1 to 5 mm larger than a single side of the groove body.

[0022] Furthermore, the material of the second dielectric layer is the same as that of the first dielectric layer, and the thickness of the second dielectric layer is 1 / 2 of the depth of the slot body.

[0023] Furthermore, the protective layer is a silk-screen solder resist layer or a cover film layer.

[0024] In a second aspect, the present invention further provides a copper-based circuit board, which is manufactured using the above-mentioned copper-based circuit board manufacturing method.

[0025] By adopting the above technical solution, the entire production method has low production cost, is simple and efficient, improves the reliability of the product, and gives full play to the good high current and high heat dissipation application performance of the copper-based circuit board. By adopting an embedded circuit pattern structure, the dielectric layer and the circuit pattern are pressed into the groove of the copper substrate, which effectively increases the bonding strength between the dielectric layer and the copper substrate, avoids the delamination and falling off of the pattern, and at the same time meets the requirement that the circuit pattern is not higher than the surface of the copper substrate, so that the copper-based circuit board is more reliable during the installation and use process, and avoids the problems of circuit falling off, bumping, etc. Based on the structural design and production method of the copper-based circuit board, the reasonable design of the circuit pattern and the pressing layout structure during the production process, combined with the overall production process, forms an effective full-process production effect, improves the reliability of the product, and gives full play to the good high current and high heat dissipation application performance of the copper-based high heat dissipation circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a flow chart of the copper-based circuit board manufacturing method of the present invention;

[0028] Figure 2 It is a structural diagram of a copper-based circuit board in the prior art;

[0029] Figure 3 This is a schematic structural diagram of a dry film layer attached to a copper substrate in an embodiment of the present invention;

[0030] Figure 4 Schematic diagram of the structure of opening a window on the dry film layer in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the structure of opening a window on the dry film layer in an embodiment of the present invention;

[0032] Figure 6 Schematic diagram of the structure of a copper substrate with a slot body in an embodiment of the present invention;

[0033] Figure 7 Schematic diagram of the structure of the copper clad plate in an embodiment of the present invention;

[0034] Figure 8 A schematic structural diagram of a copper-clad laminate having a circuit pattern according to an embodiment of the present invention;

[0035] Figure 9This is a schematic structural diagram of a copper substrate with a slot body and a copper clad laminate with a circuit pattern before lamination according to an embodiment of the present invention;

[0036] Figure 10 This is a schematic structural diagram of a copper substrate with a slot body and a copper clad laminate with a circuit pattern after being pressed together according to an embodiment of the present invention;

[0037] Figure 11 for Figure 10 A schematic diagram of the structure after etching away the surface pattern;

[0038] Figure 12 This is a schematic structural diagram of an embodiment of the present invention after the dielectric layer on the surface of the copper substrate is removed;

[0039] Figure 13 Schematic diagram of the structure of a copper-based circuit board according to an embodiment of the present invention.

[0040] The following are the descriptions of the reference numerals:

[0041] 100-copper substrate, 101-dry film layer, 1011-window pattern, 102-slot body;

[0042] 200-copper clad plate, 201-surface copper layer, 2011-surface pattern, 202-first dielectric layer, 203-circuit layer copper layer, 2031-circuit pattern;

[0043] 300 - dielectric layer, 301 - second dielectric layer;

[0044] 400-Protection layer. DETAILED DESCRIPTION

[0045] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0046] The present invention provides a method for manufacturing a copper-based circuit board. Figure 1 , Figure 1 This is a flow chart of a method for manufacturing a copper-based circuit board according to the present invention. The copper-based circuit board includes a copper substrate and a copper-clad laminate. The copper-clad laminate includes a surface copper layer, a first dielectric layer, and a circuit layer copper layer laminated from top to bottom. The manufacturing method includes the following steps:

[0047] S1: A dry film layer is applied to the surface of a copper substrate, and windows are opened in the dry film layer, wherein the pattern of the window opening is the same as the pattern of the groove body to be subsequently etched;

[0048] S2: etching a groove on the copper substrate at the position of the window pattern by etching;

[0049] S3: removing the dry film layer to obtain a copper substrate having a trough body;

[0050] S4: forming a circuit pattern on the copper layer of the circuit layer of the copper clad laminate, and forming a surface pattern corresponding to the circuit pattern on the surface copper layer of the copper clad laminate, wherein the area of the surface pattern is larger than the notch area of the slot body, to obtain a copper clad laminate having a circuit pattern;

[0051] S5: taking a second dielectric layer and placing it between the copper substrate with the slot body and the copper clad laminate with the circuit pattern, pressing the copper substrate with the slot body and the copper clad laminate with the circuit pattern, pressing the circuit pattern into the slot body, pressing the first dielectric layer and the second dielectric layer together to form a dielectric layer, the dielectric layer being located on the surface of the copper substrate and inside the slot body, and the surface pattern being pressed into the dielectric layer;

[0052] S6: etching away the surface pattern;

[0053] S7: removing the dielectric layer on the surface of the copper substrate by polishing;

[0054] S8: Making a protective layer on the surface of the copper substrate to obtain a copper-based circuit board.

[0055] The copper-based circuit board manufacturing method of the present invention has low manufacturing cost, is simple and efficient, realizes an embedded circuit pattern structure, avoids problems such as pattern delamination, shedding, and bumping, improves product reliability, and ensures the copper-based circuit board's good high current and high heat dissipation application performance.

[0056] The present invention is described in detail below with reference to the accompanying drawings.

[0057] Please refer to Figure 2 , Figure 2 FIG. 1 is a schematic diagram of the structure of a copper-based circuit board in the prior art. Currently, a general method for manufacturing a copper-based circuit board is to add a dielectric layer 300 to the surface of a copper substrate 100, form a circuit pattern 2031 on the dielectric layer 300, and then cover the circuit pattern 2031 with a protective layer 400. The prior art manufacturing method has high production costs. If slight delamination occurs, it will cause serious consequences during application. Since the circuit pattern 2031 is located above the copper substrate 100, there is a relatively thick dielectric layer 300 between the circuit pattern 2031 and the copper substrate 100, which will result in the heat dissipation efficiency of the copper substrate 100 not being effectively utilized.

[0058] Please refer to Figures 3 to 8An embodiment of the present invention provides a method for manufacturing a copper-based circuit board, wherein the copper-based circuit board includes a copper substrate 100 and a copper-clad laminate 200, wherein the copper-clad laminate 200 includes a surface copper layer 201, a first dielectric layer 202, and a circuit layer copper layer 203 pressed together from top to bottom.

[0059] Please refer to Figure 3 and Figure 4 A dry film layer 101 is applied to the surface of a copper substrate 100. Windowing is performed in the dry film layer 101. The dry film layer 101 is applied to prepare for the subsequent production of the trough. Therefore, the window pattern 1011 is identical to the pattern of the trough to be subsequently etched. In this embodiment, the copper substrate 100 has a thickness of 2 to 5 mm.

[0060] Please refer to Figure 5 , etching is performed to form a groove 102 on the copper substrate 100 at the location of the window pattern 1011. In this embodiment, the groove 102 has a depth of 1 to 3 mm and is formed by multiple etching processes, with each etching process being 1 / 5 to 1 / 3 of the depth of the groove 102. If delamination of the dry film layer 101 occurs during the etching process, the film is stripped, and step S1 is repeated before continuing the etching process.

[0061] After the tank body 102 is manufactured, the dry film layer 101 is removed to obtain Figure 6 The copper base plate with the slot body is shown.

[0062] Please continue reading Figure 7 and Figure 8 The copper clad laminate 200 includes a surface copper layer 201, a first dielectric layer 202, and a circuit layer copper layer 203 laminated from top to bottom. A circuit pattern 2031 is formed on the circuit layer copper layer 203 of the copper clad laminate 200. A surface pattern 2011 corresponding to the circuit pattern 2031 is formed on the surface copper layer 201 of the copper clad laminate 200. Figure 8 The copper-clad laminate with a circuit pattern is shown. The area of the surface pattern 2011 is larger than the notch area of the slot body 102. Specifically, a single side of the surface pattern 2011 is 1 to 5 mm larger than a single side of the slot body 102. During the subsequent pressing process, the surface pattern 2011 can effectively act as a buffer, pressing the first dielectric layer 202 into the slot body 102 while preventing the surface pattern 2011 from being pressed into the slot body 102. In this embodiment, the thickness of the first dielectric layer 202 of the copper-clad laminate 200 is the same as the depth of the slot body 102.

[0063] In this embodiment, the surface copper layer 201 is formed into the surface pattern 2011. On the one hand, this effectively avoids the problem of "yin-yang side" when forming the circuit pattern 2031. That is, the copper on one side is completely retained, and the other side is the pattern. In this case, due to the large difference in expansion and contraction between the two sides, the board is prone to warping, affecting subsequent production. On the other hand, this avoids the situation in which the first dielectric layer 202 can only overflow to both sides during the subsequent pressing process, resulting in the glue flow of the first dielectric layer 202 not being able to spread in time. If the amount of the first dielectric layer 202 pressed into the slot 102 is too large, it will affect the position of the circuit pattern 2031, which is not conducive to pressing and filling.

[0064] Please continue reading Figure 9 and Figure 10 A second dielectric layer 301 is placed between the copper substrate with the slot body and the copper-clad laminate with the circuit pattern. The copper substrate with the slot body and the copper-clad laminate with the circuit pattern are pressed together, and the circuit pattern 2031 is pressed into the slot body 102. The first dielectric layer 202 and the second dielectric layer 301 are pressed together to form a dielectric layer 300. The dielectric layer 300 is located on the surface of the copper substrate 100 and within the slot body 102, and the surface pattern 2011 is pressed into the dielectric layer 300. The material of the second dielectric layer 301 is the same as that of the first dielectric layer 202, and the thickness of the second dielectric layer 301 is 1 / 2 of the depth of the slot body 102.

[0065] Please refer to Figure 11 , the surface pattern 2011 is etched away by etching.

[0066] Please refer to Figure 12 , by polishing, fine polishing and finishing can be used to remove the dielectric layer 300 on the surface of the copper substrate 100.

[0067] Please refer to Figure 13 A protective layer 400 is made on the surface of the copper substrate 100, and the protective layer 400 is a silk screen solder mask layer or a cover film layer to obtain a copper-based circuit board.

[0068] The present invention also provides a copper-based circuit board, which is manufactured using the copper-based circuit board manufacturing method in any of the above embodiments.

[0069] By providing a groove body on the copper substrate, the dielectric layer and the circuit pattern are pressed into the copper substrate, which effectively increases the bonding strength between the dielectric layer and the copper substrate, avoids delamination and falling off of the pattern, effectively improves the heat dissipation effect and efficiency of the circuit board during operation, and achieves the requirement that the circuit pattern is not higher than the surface of the copper substrate, making the circuit board installation process and use process more reliable, avoiding problems such as circuit falling off and bumping, improving product reliability, and giving full play to the good high current and high heat dissipation application performance of the copper-based circuit board.

[0070] By adopting the above technical solution, the entire production method has low production cost, is simple and efficient, improves product reliability, and gives full play to the good high current and high heat dissipation application performance of the copper-based circuit board. By adopting an embedded circuit pattern structure, the dielectric layer and the circuit pattern are pressed into the groove of the copper substrate, which effectively increases the bonding strength between the dielectric layer and the copper substrate, avoids delamination and falling off of the pattern, and at the same time meets the requirement that the circuit pattern is not higher than the surface of the copper substrate, making the copper-based circuit board more reliable during the installation and use process, and avoiding problems such as circuit falling off and bumping.

[0071] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

[0072] In the description of the patent of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "row", "column", 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 the patent of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation to the patent of the present invention.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention patent, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0074] In invention patents, unless otherwise expressly specified or limited, terms such as "install," "connect," "connect," "fix," and "fixed" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components, unless otherwise expressly limited. A person of ordinary skill in the art can understand the specific meanings of the above terms in invention patents based on the specific circumstances.

[0075] In the present invention, unless otherwise expressly specified or limited, a first feature "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

Claims

1. A method for manufacturing a copper-based circuit board, wherein the copper-based circuit board comprises a copper substrate and a copper-clad laminate, wherein the copper-clad laminate comprises a surface copper layer, a first dielectric layer, and a circuit layer copper layer laminated from top to bottom, characterized in that: The preparation method comprises the following steps: A dry film layer is attached to the surface of the copper substrate, and windows are opened in the dry film layer, wherein the pattern of the window opening is the same as the pattern of the groove body to be subsequently etched; Etching a groove on the copper substrate at the position of the window pattern by etching; removing the dry film layer to obtain a copper substrate having a trough body; A circuit pattern is formed on the copper layer of the circuit layer of the copper clad laminate, and a surface pattern corresponding to the circuit pattern is formed on the surface copper layer of the copper clad laminate, wherein the area of the surface pattern is larger than the notch area of the notch body, thereby obtaining a copper clad laminate having a circuit pattern; A second dielectric layer is placed between a copper substrate having a slot body and a copper-clad laminate having a circuit pattern. The copper substrate having a slot body and the copper-clad laminate having a circuit pattern are pressed together, and the circuit pattern is pressed into the slot body. The first dielectric layer and the second dielectric layer are pressed together to form a dielectric layer. The dielectric layer is located on the surface of the copper substrate and inside the slot body, and the surface pattern is pressed into the dielectric layer. etching away the surface pattern by etching; removing the dielectric layer on the surface of the copper substrate by polishing; A protective layer is formed on the surface of the copper substrate to obtain a copper-based circuit board.

2. The method for manufacturing a copper-based circuit board according to claim 1, wherein: The copper substrate has a thickness of 2 to 5 mm.

3. The method for manufacturing a copper-based circuit board according to claim 1, wherein: The depth of the groove body is 1 to 3 mm, and the groove body is formed by etching multiple times, with the depth of each etching being 1 / 5 to 1 / 3 of the groove body depth.

4. The method for manufacturing a copper-based circuit board according to claim 1, wherein: The thickness of the first dielectric layer of the copper clad laminate is the same as the depth of the slot.

5. The method for manufacturing a copper-based circuit board according to claim 1, wherein: A single side of the surface pattern is 1 to 5 mm larger than a single side of the groove body.

6. The method for manufacturing a copper-based circuit board according to claim 1, wherein: The material of the second dielectric layer is the same as that of the first dielectric layer, and the thickness of the second dielectric layer is 1 / 2 of the depth of the slot body.

7. The method for manufacturing a copper-based circuit board according to claim 1, wherein: The protective layer is a silk screen solder resist layer or a cover film layer.

8. A copper-based circuit board, characterized in that: The copper-based circuit board is manufactured by the copper-based circuit board manufacturing method according to any one of claims 1 to 7.

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