Method for manufacturing copper substrate

Abstract

The invention discloses a method for manufacturing a copper substrate. The manufacturing method of the copper substrate comprises a preposition step of providing a circuit substrate, the circuit substrate is provided with a first surface and a second surface which are opposite to each other, a plurality of copper circuits are formed on the first surface of the circuit substrate, and the first thickness of each copper circuit is not less than 100 micrometers; a first resin ink printing step of filling resin ink among the plurality of copper circuits in a printing mode and covering the plurality of copper circuits to form a first printing ink layer; a first baking step of baking the circuit substrate on which the first printing ink layer is formed; and a pressing step: forming a polypropylene adhesive layer on the first printing ink layer in a pressing mode so as to form the copper substrate.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a substrate, in particular to a method for manufacturing a copper substrate. Background Art

[0002] In existing thick copper manufacturing methods, it is usually necessary to attach a polypropylene adhesive layer on copper circuits to fill the gaps between the copper circuits. However, due to the relatively high thickness of the copper circuits, too many layers of polypropylene adhesive are used to ensure that the gaps between the copper circuits can be filled by the polypropylene adhesive layer, which also causes the problem of excessive substrate thickness. Summary of the Invention

[0003] The present invention discloses a method for manufacturing a copper substrate, mainly for improving the problem of excessive substrate thickness caused by using too many polypropylene adhesive layers to fill the gaps between copper circuits in existing thick copper manufacturing methods.

[0004] One embodiment of the present invention discloses a method for manufacturing a copper substrate, which includes: a pre-step of providing a circuit substrate having a first surface and a second surface opposite to each other, wherein a plurality of copper circuits are formed on the first surface of the circuit substrate, and the first thickness of each copper circuit is not less than 100 microns; a first resin ink printing step of filling resin ink between the plurality of copper circuits on the first surface and covering the plurality of copper circuits by printing to form a first printed ink layer on the first surface of the circuit substrate; a first baking step of baking the circuit substrate having the first printed ink layer; and

[0005] a lamination step of forming a polypropylene adhesive layer on the first printed ink layer by lamination to form a copper substrate.

[0006] Optionally, the first thickness of each copper circuit is between 127 microns and 380 microns, the second thickness of the polypropylene adhesive layer is between 2 mils and 32 mils, and the third thickness of the copper substrate is between 18 mils and 236 mils.

[0007] Optionally, based on the total weight of the resin ink being 100 wt%, the resin ink contains 20 wt% to 25 wt% of tris(glycidylamino)m-cresol, 5 wt% to 10 wt% of epoxy resin, and 60 wt% to 65 wt% of silica.

[0008] Optionally, the resin ink has a pencil hardness of 6H or greater, a glass transition temperature between 140°C and 170°C, a first coefficient of thermal expansion between 14 ppm / °C and 24 ppm / °C, and a second coefficient of thermal expansion between 63 ppm / °C and 73 ppm / °C; wherein the first coefficient of thermal expansion is defined as the coefficient of thermal expansion of the resin ink below the glass transition temperature, and the second coefficient of thermal expansion is defined as the coefficient of thermal expansion of the resin ink above the glass transition temperature.

[0009] Optionally, in the first resin ink printing step, a first printed ink layer is formed on the first surface of the circuit board by a squeegee at a squeegee angle between 15 degrees and 30 degrees, a pressure between 0.2 Mpa and 0.45 Mpa, and a printing speed between 100 mm / s and 450 mm / s.

[0010] Optionally, in the first baking step, the circuit board having the first printed ink layer formed thereon is baked at a baking temperature between 90°C and 120°C for 60 minutes to 90 minutes.

[0011] Optionally, after the first baking step and before the lamination step, the method for manufacturing the copper substrate further includes a first grinding step of removing a portion of the first printed ink layer by grinding to expose the copper circuit on the first surface from the first printed ink layer.

[0012] Optionally, in the pre-step, a plurality of copper circuits are formed on both the first surface and the second surface of the circuit board; wherein, after the first baking step and before the lamination step, the printing method of the copper substrate further includes a second resin ink printing step and a second baking step; wherein, in the second resin ink printing step, the resin ink is filled between the plurality of copper circuits on the second surface and covers the plurality of copper circuits by printing to form a second printed ink layer on the second surface of the circuit board; wherein, in the second baking step, the circuit board having the first printed ink layer and the second printed ink layer formed thereon is baked.

[0013] Optionally, in the lamination step, two polypropylene adhesive layers are formed on the first printed ink layer and the second printed ink layer respectively by lamination.

[0014] Optionally, in the second resin ink printing step, a second printed ink layer is formed on the second surface of the circuit board by a squeegee at a squeegee angle between 15 degrees and 30 degrees, a pressure between 0.2 Mpa and 0.45 Mpa, and a printing speed between 100 mm / s and 450 mm / s.

[0015] Optionally, in the second baking step, the circuit board formed with the first printed ink layer and the second printed ink layer is baked at a baking temperature between 90°C and 120°C for 60 minutes to 90 minutes.

[0016] Optionally, after the second baking step and before the lamination step, the method for manufacturing the copper substrate further includes a second grinding step to remove part of the first printed ink layer and part of the second printed ink layer by grinding, so that the copper circuits on the first surface and the copper circuits on the second surface are respectively exposed from the first printed ink layer and the second printed ink layer.

[0017] In summary, the method for manufacturing the copper substrate provided by the present invention can improve the problem of excessive substrate thickness caused by using too many polypropylene glue layers to fill the gaps between copper circuits in the existing thick copper manufacturing method through the technical solutions of "the first resin ink printing step, filling the resin ink between the multiple copper circuits on the first surface and covering the multiple copper circuits by printing to form the first printed ink layer on the first surface of the circuit board" and "the lamination step, forming the polypropylene glue layer on the first printed ink layer by lamination".

[0018] In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, these descriptions and drawings are only used to illustrate the present invention and do not impose any limitation on the protection scope of the present invention. Description of the Drawings

[0019] Figure 1 It is a flowchart of the method for manufacturing the copper substrate according to an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of the pre-step of the method for manufacturing the copper substrate according to an embodiment of the present invention.

[0021] Figure 3 It is a schematic diagram of the first resin ink printing step of the method for manufacturing the copper substrate according to an embodiment of the present invention.

[0022] Figure 4 It is a schematic diagram of the first grinding step of the method for manufacturing the copper substrate according to an embodiment of the present invention.

[0023] Figure 5 It is a schematic diagram of the copper substrate according to an embodiment of the present invention.

[0024] Figure 6 It is a flowchart of the method for manufacturing the copper substrate according to another embodiment of the present invention.

[0025] Figure 7Schematic diagram of the pre - step of the manufacturing method of the copper substrate according to another embodiment of the present invention.

[0026] Figure 8 Schematic diagram of the first resin ink printing step of the manufacturing method of the copper substrate according to another embodiment of the present invention.

[0027] Figure 9 Schematic diagram of the second resin ink printing step of the manufacturing method of the copper substrate according to another embodiment of the present invention.

[0028] Figure 10 Schematic diagram of the second grinding step of the manufacturing method of the copper substrate according to an embodiment of the present invention.

[0029] Figure 11 Schematic diagram of the copper substrate according to another embodiment of the present invention. Detailed implementation manners

[0030] The following is to illustrate the implementation manners of the "manufacturing method of copper substrate" disclosed in the present invention through specific specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Additionally, the drawings of the present invention are only for simple schematic illustration and are not drawn according to actual dimensions, which is stated in advance. The following implementation manners will further detail the related technical content of the present invention, but the disclosed content is not used to limit the protection scope of the present invention.

[0031] It should be understood that although terms such as "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another, or one signal from another. Additionally, the term "or" used herein should, depending on the actual situation, possibly include any one or a combination of more of the associated listed items.

[0032] [Manufacturing method of copper substrate]

[0033] Please refer to Figure 1 as shown in Figure 1 The flowchart of the manufacturing method of the copper substrate according to an embodiment of the present invention. An embodiment of the present invention provides a manufacturing method of a copper substrate. The manufacturing method of the copper substrate includes a pre - step S110, a first resin ink printing step S120, a first baking step S130, and a lamination step S140. Of course, the manufacturing method of the copper substrate may include other steps according to requirements, and the present invention does not limit this.

[0034] Please refer to Figure 2 as shown Figure 2 which is a schematic diagram of the pre - step of the manufacturing method of the copper substrate according to an embodiment of the present invention. In the pre - step S110, a circuit substrate 1 is provided. The circuit substrate 1 has a first surface 1a and a second surface 1b opposite to each other. A plurality of copper lines 11 are formed on the first surface 1a of the circuit substrate 1, and a first thickness T1 of each of the copper lines 11 is not less than 100 microns. It is worth mentioning that the first thickness T1 of each of the copper lines 11 is relatively thick. Therefore, other lines with a thickness less than 100 microns are not suitable for comparison with the copper lines in the present invention. Optionally, the first thickness T1 of each of the copper lines 11 is between 127 microns and 380 microns.

[0035] Please refer to Figure 3 as shown Figure 3 which is a schematic diagram of the first resin ink printing step of the manufacturing method of the copper substrate according to an embodiment of the present invention. In the first resin ink printing step S120, the resin ink is filled between the plurality of copper lines 11 on the first surface 1a and covers the plurality of copper lines 11 by a printing method to form a first printed ink layer 2 on the first surface of the circuit substrate.

[0036] It is worth mentioning that the copper lines 11 provided in the pre - step S110 of the present invention are relatively thick. If the polypropylene glue layer is directly attached to the copper lines 11, it is easy to cause a gap to be formed between the polypropylene glue layer and the copper lines 11 or too much polypropylene glue layer needs to be used.

[0037] Based on the total weight of the resin ink being 100 wt%, the resin ink contains 20 wt% to 25 wt% of triglycidylaminometacresol, 5 wt% to 10 wt% of epoxy resin, and 60 wt% to 65 wt% of silica. Optionally, the resin ink may further contain a hardener and a defoaming agent. Based on the total weight of the resin ink being 100 wt%, the content of the hardener is between 1 wt% and 5 wt%, and the content of the defoaming agent is between 1 wt% and 5 wt%, but the present invention is not limited thereto.

[0038] The resin ink has a pencil hardness greater than or equal to 6H, a glass transition temperature between 140 °C and 170 °C, a first coefficient of thermal expansion (α1) between 14 ppm / °C and 24 ppm / °C, and a second coefficient of thermal expansion (α2) between 63 ppm / °C and 73 ppm / °C. The first coefficient of thermal expansion (α1) is defined as the coefficient of thermal expansion of the resin ink below the glass transition temperature, and the second coefficient of thermal expansion (α2) is defined as the coefficient of thermal expansion of the resin ink above the glass transition temperature.

[0039] In the first resin ink printing step S120, the first printed ink layer 2 is formed on the first surface 1a of the circuit board 1 by a squeegee S at a squeegee angle between 15 degrees and 30 degrees, a pressure between 0.2 Mpa and 0.45 Mpa, and a printing speed between 100 mm / s and 450 mm / s.

[0040] In the first baking step S130, the circuit board 1 formed with the first printed ink layer 2 is baked. Optionally, in the first baking step S130, the circuit board 1 formed with the first printed ink layer 2 is baked at a baking temperature between 90 °C and 120 °C for 60 minutes to 90 minutes, but the present invention is not limited thereto.

[0041] Please refer to Figure 1 and Figure 4 As shown, after the first baking step S130 and before the lamination step S140, the manufacturing method of the copper substrate may further include a first grinding step S1301 to remove a part of the first printed ink layer 2 by grinding, so that the copper circuit 11 located on the first surface 1a is exposed from the first printed ink layer 2. After the first grinding step S1301, the copper circuit 11 located on the first surface 1a may be flush with the first printed ink layer 2, but the present invention is not limited thereto.

[0042] Please refer to Figure 5 As shown, Figure 5 is a schematic diagram of a copper substrate according to an embodiment of the present invention. In the lamination step S140, a polypropylene glue layer 3 is formed on the first printed ink layer 2 by lamination, thereby forming a copper substrate 100. It is worth mentioning that through the first grinding step S1301, the bonding force between the polypropylene glue layer 3 and the copper circuit 11 can be improved, but the manufacturing method of the copper substrate of the present invention is not limited to necessarily including the first grinding step S1301.

[0043] Optionally, the second thickness T2 of the polypropylene glue layer 3 is between 2 mils and 32 mils, and the third thickness T3 of the copper substrate 100 is between 18 mils and 236 mils, but the present invention is not limited thereto. More preferably, the second thickness T2 of the polypropylene glue layer 3 is between 10 mils and 25 mils, and the third thickness T3 of the copper substrate 100 is between 50 mils and 200 mils, but the present invention is not limited thereto.

[0044] Please refer to Figure 6 and Figure 7 As shown, Figure 6Flow chart of the manufacturing method of the copper substrate according to another embodiment of the present invention, and Figure 7 Schematic diagram of the pre - steps of the manufacturing method of the copper substrate according to another embodiment of the present invention. In the pre - step S110’ of another embodiment, a plurality of the copper circuits 11 are formed on both the first surface 1a and the second surface 1b of the circuit substrate 1. After the first baking step S130 and before the lamination step S140’, the printing method of the copper substrate may further include a second resin ink printing step S131 and a second baking step S132.

[0045] Please refer to Figures 8 to 11 as shown Figure 8 Schematic diagram of the first resin ink printing step of the manufacturing method of the copper substrate according to another embodiment of the present invention, Figure 9 Schematic diagram of the second resin ink printing step of the manufacturing method of the copper substrate according to another embodiment of the present invention, Figure 10 Schematic diagram of the second grinding step of the manufacturing method of the copper substrate according to an embodiment of the present invention, and Figure 11 Schematic diagram of the copper substrate according to another embodiment of the present invention.

[0046] The first resin ink printing step S120 of this embodiment may be the same as that of the previous embodiment, and the present invention will not elaborate herein. In the second resin ink printing step S131, the resin ink is filled between the plurality of copper circuits 11 on the second surface 1b and covers the plurality of copper circuits 11 by printing, so as to form a second printing ink layer 4 on the second surface 1b of the circuit substrate. The resin ink for forming the first printing ink layer 2 may be the same as or different from the resin ink for forming the second printing ink layer 4, and the present invention does not limit this.

[0047] In the second resin ink printing step S131, the second printing ink layer 4 is formed on the second surface 1b of the circuit substrate 1 by a squeegee S at a squeegee angle between 15 degrees and 30 degrees, a pressure between 0.2 Mpa and 0.45 Mpa, and a printing speed between 100 mm / s and 450 mm / s.

[0048] In the second baking step S132, the circuit substrate 1 formed with the first printing ink layer 2 and the second printing ink layer 4 is baked. Optionally, in the second baking step S132, the circuit substrate 1 formed with the first printing ink layer 2 and the second printing ink layer 4 is baked at a baking temperature between 90 °C and 120 °C for 60 minutes to 90 minutes, but the present invention is not limited thereto.

[0049] As Figure 6 andFigure 11 As shown, after the second baking step S132 and before the lamination step S140', the method for manufacturing the copper substrate may further include a second grinding step S133 to remove part of the first printed ink layer 2 and part of the second printed ink layer 4 by grinding, so that the copper traces 11 on the first surface 1a and the copper traces 11 on the second surface 1b are respectively exposed from the first printed ink layer 2 and the second printed ink layer 4.

[0050] After the second grinding step S133, the copper traces 11 on the first surface 1a and the copper traces 11 on the second surface 1b may be flush with the first printed ink layer 2 and the second printed ink layer 4 respectively, but the present invention is not limited thereto. In addition, the method for manufacturing the copper substrate of the present invention is not limited to necessarily including the second grinding step S133, and in this embodiment, the method for manufacturing the copper substrate does not include the first grinding step S1301.

[0051] In addition, in the lamination step S140', two polypropylene adhesive layers 3 are respectively formed on the first printed ink layer 2 and the second printed ink layer 4 by lamination, thereby forming a copper substrate 100'.

[0052] [Copper Substrate]

[0053] Please refer to Figure 5 As shown, an embodiment of the present invention further provides a copper substrate 100. The copper substrate 100 may be obtained, for example, by performing the aforementioned method for manufacturing the copper substrate, but the present invention is not limited thereto. The copper substrate 100 includes a circuit substrate 1, a first printed ink layer 2, and a polypropylene adhesive layer 3.

[0054] The circuit substrate 1 has a first surface 1a and a second surface 1b opposite to each other. A plurality of copper traces 11 are formed on the first surface 1a of the circuit substrate 1, and the first thickness T1 of each copper trace 11 is not less than 100 microns.

[0055] The first printed ink layer 2 is formed on the first surface 1a, and the first printed ink layer 2 is formed between a plurality of the copper circuits 11 on the first surface 1a. The polypropylene glue layer 3 is formed on the first printed ink layer 2 and the copper circuits 11. In other words, the first printed ink layer 2 is located between the circuit board 1 and the polypropylene glue layer 3, and the polypropylene glue layer 3 may not be in direct contact with the first surface 1a of the circuit board 1. In addition, only one polypropylene glue layer 3 may be formed on the first printed ink layer 2 of the copper substrate 100, but the present invention is not limited thereto. Additionally, the top surface of the first printed ink layer 2 may be flush with the copper circuits 11 on the first surface 1a, but the present invention is not limited thereto.

[0056] Optionally, the first thickness T1 of each of the copper circuits 11 is between 127 microns and 380 microns, the second thickness T2 of the polypropylene glue layer 3 is between 2 mils and 32 mils, and the third thickness T3 of the copper substrate 100 is between 18 mils and 236 mils, but the present invention is not limited thereto.

[0057] Please refer to Figure 11 As shown, in another embodiment, a plurality of the copper circuits 11 are formed on both the first surface 1a and the second surface 1b of the circuit board 100'. The copper substrate 100' may further include a second printed ink layer 4, and the second printed ink layer 4 is formed on the second surface 1b, and the second printed ink layer 4 is formed between a plurality of the copper circuits 11 on the second surface 1b.

[0058] In addition, the copper substrate 100' may include two polypropylene glue layers 3, and the two polypropylene glue layers 3 are respectively formed on the first printed ink layer 2 and the second printed ink layer 4. The second printed ink layer 4 is located between the circuit board 1 and one of the polypropylene glue layers 3. The second printed ink layer 4 is not in direct contact with the second surface 1b of the circuit board 1.

[0059] Furthermore, only one polypropylene glue layer 3 may be formed on the first printed ink layer 2 of the copper substrate 100', and only one polypropylene glue layer 3 may be formed on the second printed ink layer 4 of the copper substrate 100', but the present invention is not limited thereto. The top surfaces of the first printed ink layer 2 and the second printed ink layer 4 may be respectively flush with the copper circuits 11 on the first surface 1a and the copper circuits 11 on the second surface 1b, but the present invention is not limited thereto.

[0060] [Advantageous Effects of Embodiments of the Present Invention]

[0061] In summary, the manufacturing method of the copper substrate provided by the present invention can, through "the first resin ink printing step, filling the resin ink between the plurality of copper circuits on the first surface and covering the plurality of copper circuits by printing to form the first printed ink layer on the first surface of the circuit substrate" and "the lamination step, forming the polypropylene glue layer on the first printed ink layer by lamination", improve the problem in the existing thick copper manufacturing method that the substrate thickness is too high due to using too many polypropylene glue layers to fill the gaps between the copper circuits.

[0062] The above are only the preferred feasible embodiments of the present invention, and do not limit the patent scope of the present invention. Therefore, all equivalent technical changes made by using the content of the specification and drawings of the present invention are included in the protection scope of the present invention.

Claims

1. A method for manufacturing a copper substrate, characterized in that: The manufacturing method of the copper substrate comprises: A pre-step of providing a circuit substrate, wherein the circuit substrate has a first surface and a second surface opposite to each other, and a plurality of copper circuits are formed on the first surface of the circuit substrate, and a first thickness of each of the copper circuits is not less than 100 microns; a first resin ink printing step, filling the resin ink between the plurality of copper circuits on the first surface and covering the plurality of copper circuits by printing, so as to form a first printed ink layer on the first surface of the circuit substrate; A first baking step of baking the circuit substrate on which the first printing ink layer is formed; as well as A lamination step is performed to form a polypropylene adhesive layer on the first printing ink layer by lamination, thereby forming a copper substrate.

2. The method for manufacturing a copper substrate according to claim 1, characterized in that: The first thickness of each of the copper lines is between 127 micrometers and 380 micrometers, the second thickness of the polypropylene adhesive layer is between 2 mils and 32 mils, and the third thickness of the copper substrate is between 18 mils and 236 mils.

3. The method for manufacturing a copper substrate according to claim 1, characterized in that: Based on 100 wt % of the total weight of the resin ink, the resin ink includes 20 wt % to 25 wt % of triglycidylamino-meta-cresol, 5 wt % to 10 wt % of epoxy resin, and 60 wt % to 65 wt % of silicon dioxide.

4. The method for manufacturing a copper substrate according to claim 1, characterized in that: The resin ink has a pencil hardness greater than or equal to 6H, a glass transition temperature between 140°C and 170°C, a first thermal expansion coefficient between 14ppm / °C and 24ppm / °C, and a second thermal expansion coefficient between 63ppm / °C and 73ppm / °C; wherein the first thermal expansion coefficient is defined as the thermal expansion coefficient of the resin ink below the glass transition temperature, and the second thermal expansion coefficient is defined as the thermal expansion coefficient of the resin ink above the glass transition temperature.

5. The method for manufacturing a copper substrate according to claim 1, characterized in that: In the first resin ink printing step, the first printed ink layer is formed on the first surface of the circuit substrate by a scraper at a scraper angle between 15 degrees and 30 degrees, a pressure between 0.2Mpa and 0.45Mpa, and a printing speed between 100mm / s and 450mm / s.

6. The method for manufacturing a copper substrate according to claim 1, characterized in that: In the first baking step, the circuit substrate having the first printing ink layer formed thereon is baked at a baking temperature between 90° C. and 120° C. for 60 minutes to 90 minutes.

7. The method for manufacturing a copper substrate according to claim 1, characterized in that: After the first baking step and before the lamination step, the method for manufacturing the copper substrate further includes a first grinding step to remove a portion of the first printing ink layer by grinding so that the copper circuit located on the first surface is exposed from the first printing ink layer.

8. The method for manufacturing a copper substrate according to claim 1, characterized in that: In the preparatory step, a plurality of copper circuits are formed on both the first surface and the second surface of the circuit substrate; wherein, after the first baking step and before the lamination step, the printing method of the copper substrate further comprises a second resin ink printing step and a second baking step; wherein, in the second resin ink printing step, the resin ink is filled between the plurality of copper circuits on the second surface and covers the plurality of copper circuits by printing to form a second printed ink layer on the second surface of the circuit substrate; wherein, in the second baking step, the circuit substrate formed with the first printed ink layer and the second printed ink layer is baked.

9. The method for manufacturing a copper substrate according to claim 8, characterized in that: In the lamination step, two polypropylene adhesive layers are formed on the first printing ink layer and the second printing ink layer respectively by lamination.

10. The method for manufacturing a copper substrate according to claim 8, characterized in that: In the second resin ink printing step, the second printed ink layer is formed on the second surface of the circuit substrate by a scraper at a scraper angle between 15 degrees and 30 degrees, a pressure between 0.2Mpa and 0.45Mpa, and a printing speed between 100mm / s and 450mm / s.

11. The method for manufacturing a copper substrate according to claim 8, characterized in that: In the second baking step, the circuit substrate having the first printing ink layer and the second printing ink layer formed thereon is baked at a baking temperature between 90° C. and 120° C. for 60 minutes to 90 minutes.

12. The method for manufacturing a copper substrate according to claim 8, characterized in that: After the second baking step and before the lamination step, the method for manufacturing the copper substrate further includes a second grinding step, removing a portion of the first printing ink layer and a portion of the second printing ink layer by grinding, so that the copper circuit located on the first surface and the copper circuit located on the second surface are exposed from the first printing ink layer and the second printing ink layer, respectively.

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