Manufacturing method of hollow circuit board

Abstract

The invention provides a manufacturing method of a hollow circuit board, which relates to a combination of specific steps, and comprises a step of forming an insulating layer with a hollow pattern on a metal layer by using optical rotation sensing resin, so that the defect that an insulating groove needs to be formed by laser cutting in the later period of the insulating layer of the traditional hollow circuit board can be overcome. Therefore, the manufacturing cost can be greatly reduced.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a hollow circuit board, and in particular to a method for manufacturing a hollow circuit board capable of saving energy. Background Art

[0002] A hollow circuit board is a circuit board with holes in the inner or outer layer of a printed circuit board. It can realize more connections and functions in a limited space, and therefore can achieve lighter or smaller product designs than traditional circuit boards.

[0003] However, due to its high technical requirements, the production and processing of hollow circuit boards is more complicated than that of traditional printed circuit boards, and the cost is relatively high. The traditional hollow circuit board manufacturing process involves processing the hollow area of ​​the insulating layer, generally using knife punching or laser cutting, but this processing mode is inefficient, not only energy-consuming, but also requires more manufacturing costs. Summary of the invention

[0004] In view of the above technical problems, an object of the present invention is to provide a method for manufacturing a hollow circuit board that can save energy and cost.

[0005] To achieve the above-mentioned purpose, the present invention provides a method for manufacturing a hollow circuit board, which comprises the following steps: providing a metal layer, wherein the metal layer has an upper surface and a lower surface opposite to the upper surface; forming a patterned insulating layer on the upper surface, wherein the patterned insulating layer comprises a first pattern and a first groove formed between the first patterns, and the patterned insulating layer is formed of a photosensitive resin; forming a first patterned dry film photoresist layer and a first non-patterned dry film photoresist layer on the upper and lower surfaces of the patterned insulating layer, respectively, wherein a portion of the first patterned dry film photoresist layer is formed in the first groove, and the first patterned dry film photoresist layer comprises a second pattern and a second groove formed between the second patterns; forming a first conductive circuit layer in the second groove; removing the first patterned dry film photoresist layer and the first non-patterned dry film photoresist layer; A patterned dry film photoresist layer is formed to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; a second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer are formed on the upper and lower surfaces of the first conductive circuit layer, respectively, wherein a portion of the second non-patterned dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected to the first groove and the third groove; and the second non-patterned photoresist dry film and the second patterned photoresist dry film are removed to obtain a hollow circuit board.

[0006] Preferably, the photosensitive resin comprises a photosensitive epoxy resin, a photosensitive polyphenyloxazole or a photosensitive polyimide.

[0007] Preferably, the method for forming the patterned insulating layer comprises the following steps: forming a photosensitive insulating layer; and sequentially exposing, developing and baking the photosensitive insulating layer to form the patterned insulating layer. More preferably, the photosensitive insulating layer is formed by screen printing, coating, spraying, rolling or laminating.

[0008] Preferably, the first patterned dry film photoresist layer is formed by attaching a dry film photoresist, and then sequentially exposing and developing the dry film photoresist.

[0009] Preferably, the first non-patterned dry film photoresist layer is formed by attaching a dry film photoresist, exposing the entire surface of the dry film photoresist, and then developing it.

[0010] Preferably, the second non-patterned dry film photoresist layer is formed by attaching a dry film photoresist, exposing the entire surface of the dry film photoresist, and then developing it.

[0011] Preferably, the second patterned dry film photoresist layer is formed by attaching a dry film photoresist, and then sequentially exposing and developing the dry film photoresist.

[0012] Preferably, the thickness of the metal layer is between 12 and 72 microns.

[0013] Preferably, the thickness of the patterned insulating layer is between 5 and 40 microns.

[0014] The present invention also provides a method for manufacturing a hollow circuit board, which includes the following steps: providing a layered structure, which includes: a first non-patterned dry film photoresist layer; a metal layer, which is arranged on the first non-patterned dry film photoresist layer; a patterned insulating layer, which is arranged on the metal layer, and the patterned insulating layer includes a first pattern and a first groove formed between the first patterns, and the patterned insulating layer is formed by a photosensitive resin; a first patterned dry film photoresist layer, a portion of the first patterned dry film photoresist layer is arranged in the first groove, and the first patterned dry film photoresist layer includes a second pattern and a second groove formed between the second patterns; and a first conductive circuit layer, which is arranged in the second groove; removing the first patterned dry film photoresist layer and the first conductive circuit layer; A first non-patterned dry film photoresist layer is formed to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; a second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected to the first groove and the third groove; and the second non-patterned photoresist dry film and the second patterned photoresist dry film are removed to obtain a hollow circuit board.

[0015] The present invention further provides a hollow circuit board, which includes: a first conductive circuit layer, which is provided with grooves; a second conductive circuit layer, which is provided with grooves; and a patterned insulating layer, which is provided between the first conductive circuit layer and the second conductive circuit layer, and the patterned insulating layer is provided with grooves, wherein the grooves of the first conductive circuit layer, the grooves of the second conductive circuit layer and the grooves of the patterned insulating layer are connected, the patterned insulating layer is formed of a photosensitive resin, and the grooves of the patterned insulating layer are formed by exposing the photosensitive resin and then developing it.

[0016] Preferably, the thickness of the patterned insulating layer is between 5 and 40 microns.

[0017] According to the present invention, a method for manufacturing a hollow circuit board with simpler manufacturing process, more energy saving and lower manufacturing cost can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figures 1A to 1K The figure is a schematic flow chart of a method for manufacturing a hollow circuit board according to an embodiment of the present invention.

[0019] Figure 2 Schematic diagram of a hollow circuit board according to an embodiment of the present invention.

[0020] Reference numerals:

[0021] 10 Metal layer 60 First conductive circuit layer

[0022] 10a Upper surface 65 Space

[0023] 10b lower surface 67 groove

[0024] 20 Photosensitive insulating layer 70 Dry film photoresist

[0025] 30 Patterned insulating layer 72 Second non-patterned dry film photoresist layer

[0026] 32 First pattern 80 Dry film photoresist

[0027] 35 first groove; groove 82 second patterned dry film photoresist layer

[0028] 40 Dry film photoresist 84 Third pattern

[0029] 42 first patterned dry film photoresist layer 86 third groove

[0030] 44 second pattern 90 second conductive circuit layer

[0031] 46 second groove 92 fourth groove; groove

[0032] 50 Dry Film Photoresist 100 Hollow Circuit Board

[0033] 52 first non-patterned dry film photoresist layer 200 hollow circuit board DETAILED DESCRIPTION

[0034] In the present invention, if the terms "first" and "second" are used to describe components, the components are not limited by the terms, which are mainly used to distinguish one component from another.

[0035] The present invention provides a method for manufacturing a hollow circuit board, which comprises the following steps: providing a metal layer, wherein the metal layer has an upper surface and a lower surface opposite to the upper surface; forming a patterned insulating layer on the upper surface, wherein the patterned insulating layer comprises a first pattern and a first groove formed between the first patterns, and the patterned insulating layer is formed of a photosensitive resin; forming a first patterned dry film photoresist layer and a first non-patterned dry film photoresist layer on the upper and lower surfaces of the patterned insulating layer, respectively, wherein a portion of the first patterned dry film photoresist layer is formed in the first groove, and the first patterned dry film photoresist layer comprises a second pattern and a second groove formed between the second patterns; forming a first conductive circuit layer in the second groove; removing the first patterned dry film photoresist layer and the first non-patterned dry film photoresist layer; and removing the first patterned dry film photoresist layer and the first non-patterned dry film photoresist layer. The method comprises forming a non-patterned dry film photoresist layer on the upper surface and the lower surface of the metal layer to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; forming a second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer on the upper surface and the lower surface of the first conductive circuit layer, respectively, wherein a portion of the second non-patterned dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; etching the metal layer through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected with the first groove and the third groove; and removing the second non-patterned photoresist dry film and the second patterned photoresist dry film to obtain a hollow circuit board.

[0036] The present invention further provides a method for manufacturing a hollow circuit board, which includes the following steps: providing a layered structure, which includes: a first non-patterned dry film photoresist layer; a metal layer, which is disposed on the first non-patterned dry film photoresist layer; a patterned insulating layer, which is disposed on the metal layer, and the patterned insulating layer includes a first pattern and a first groove formed between the first patterns, and the patterned insulating layer is formed by a photosensitive resin; a first patterned dry film photoresist layer, a portion of the first patterned dry film photoresist layer is disposed in the first groove, and the first patterned dry film photoresist layer includes a second pattern and a second groove formed between the second patterns; and a first conductive circuit layer, which is disposed in the second groove; removing the first patterned dry film photoresist layer and the first conductive circuit layer; A first non-patterned dry film photoresist layer is formed to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; a second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected to the first groove and the third groove; and the second non-patterned photoresist dry film and the second patterned photoresist dry film are removed to obtain a hollow circuit board.

[0037] The following will further describe the method for manufacturing a hollow circuit board provided by the present invention in detail with reference to the drawings and embodiments. These embodiments are only used for illustration and are not intended to limit the scope of the present invention.

[0038] The method for manufacturing the hollow circuit board 100 provided in the embodiment of the present invention includes the following steps.

[0039] Step S1, see Figure 1A , providing a metal layer 10, wherein the metal layer has an upper surface 10a and a lower surface 10b opposite to the upper surface.

[0040] In this embodiment, the thickness of the metal layer 10 is between 12 and 72 micrometers. In this embodiment, the material of the metal layer 10 is copper. In some embodiments, the material of the metal layer 10 is an alloy. In some embodiments, the material of the metal layer 10 is other metals.

[0041] Step S2, such as Figure 1BAs shown, a photosensitive insulating layer 20 is formed on the upper surface 10a with a photosensitive resin. The formation method is not particularly limited, and can be a liquid wet process, including screen printing, coating, and spraying; or can be a process for dry film photosensitive insulating materials, including rolling and laminating. The photosensitive resin can be a photosensitive epoxy resin, a photosensitive polyphenyloxazole (PSPBO), or a photosensitive polyimide (PSPI). In this embodiment, the photosensitive resin is a photosensitive polyimide.

[0042] Step S3, sequentially exposing, developing and baking the photosensitive insulating layer 20 to form a patterned insulating layer 30. Figure 1C As shown, the patterned insulating layer 30 includes a first pattern 32 and a first groove 35 formed between the first patterns 32. After the photosensitive insulating layer 20 is cured (baking temperature 150-200° C.), it has high temperature resistance and chemical solvent resistance and can withstand high temperatures of 150-320° C. In this embodiment, the thickness of the patterned insulating layer 30 is between 5 and 40 microns.

[0043] Step S4, see Figure 1D , a dry film photoresist 40 and a dry film photoresist 50 are attached to the patterned insulating layer 30 and the lower surface 10b of the metal layer, respectively. In the present invention, the attaching order of the dry film photoresist 40 and the dry film photoresist 50 is not limited. In some embodiments, the dry film photoresist 40 is attached first, and then the dry film photoresist 50 is attached. In some embodiments, the dry film photoresist 50 is attached first, and then the dry film photoresist 40 is attached. In this embodiment, the dry film photoresist 40 and the dry film photoresist 50 are attached at the same time, which can further simplify the manufacturing process. In the present invention, the dry film photoresist 40 and the dry film photoresist 50 can be the same or different.

[0044] Step S5, see Figure 1E The dry film photoresist 40 is exposed to the desired pattern, and then developed to obtain a first patterned dry film photoresist layer 42 formed on the patterned insulating layer 30; the entire surface of the dry film photoresist 50 is exposed, and then developed to obtain a first non-patterned dry film photoresist layer 52 formed on the lower surface 10b. The photoresist layer 52 has a plating resistance. Figure 1E As shown, the first patterned dry film photoresist layer 42 includes second patterns 44 and second grooves 46 formed between the second patterns, and the photoresist layer 42 is partially formed in the first grooves 35 .

[0045] Step S6, see Figure 1F, forming a first conductive circuit layer 60 in the second groove 46. In this embodiment, the specific steps of forming the first conductive circuit layer 60 are: forming a seed layer in the second groove 60 and on the surface of the patterned insulating layer 30 by sputtering or electroless plating, and then forming the first conductive circuit layer 60 by electroplating.

[0046] Step S7, see Figure 1G , remove the first patterned dry film photoresist layer 42 and the first non-patterned dry film photoresist layer 52 to expose the space 65 formed after the second pattern 44 is removed and expose the lower surface 10b of the metal layer. In this embodiment, the first patterned dry film photoresist layer 42 and the first non-patterned dry film photoresist layer 52 are removed at the same time. In some embodiments, the first patterned dry film photoresist layer 42 is removed first, and then the first non-patterned dry film photoresist layer 52 is removed. In some embodiments, the first non-patterned dry film photoresist layer 52 is removed first, and then the first patterned dry film photoresist layer 42 is removed.

[0047] Step S8, see Figure 1H , a dry film photoresist 70 and a dry film photoresist 80 are attached to the first conductive circuit layer 60 and the lower surface 10b of the metal layer, respectively. In the present invention, the attaching order of the dry film photoresist 70 and the dry film photoresist 80 is not limited. In some embodiments, the dry film photoresist 70 is attached first, and then the dry film photoresist 80 is attached. In some embodiments, the dry film photoresist 80 is attached first, and then the dry film photoresist 70 is attached. In this embodiment, the dry film photoresist 70 and the dry film photoresist 80 are attached at the same time, which can further simplify the manufacturing process. In the present invention, the dry film photoresist 70 and the dry film photoresist 80 can be the same or different. In the present invention, the dry film photoresist 40, the dry film photoresist 50, the dry film photoresist 70 and the dry film photoresist 80 can be the same or different.

[0048] Step S9, see Fig. 1I The entire surface of the dry film photoresist 70 is exposed and then developed to obtain a second non-patterned dry film photoresist layer 72 formed on the first conductive circuit layer 60; the dry film photoresist 80 is exposed to a desired pattern and then developed to obtain a second patterned dry film photoresist layer 82 formed on the lower surface 10b. The second non-patterned dry film photoresist layer 72 has a plating resistance. Fig. 1I As shown, the second patterned dry film photoresist layer 82 includes third patterns 84 and third grooves 86 formed between the third patterns, and the third grooves 86 correspond to the first grooves 35 .

[0049] Step S10, see Figure 1JThe metal layer 10 is etched through the second patterned dry film photoresist layer 82 to form a second conductive circuit layer 90 , wherein the second conductive circuit layer 90 is provided with a fourth trench 92 , and the fourth trench 92 is connected to the first trench 35 and the third trench 86 .

[0050] Step S11, see Figure 1K , the second non-patterned photoresist dry film 72 and the second patterned photoresist dry film 82 are removed to obtain a hollow circuit board 100 , wherein the fourth groove 92 is connected to the first groove 35 and the space 65 .

[0051] Based on the above manufacturing method, the present invention further provides a hollow circuit board. Please refer to the second figure, which is a schematic diagram of a hollow circuit board of an embodiment of the present invention. The hollow circuit board 200 includes: a first conductive circuit layer 60, which is provided with a groove 67; a second conductive circuit layer 90, which is provided with a groove 92; and a patterned insulating layer 30, which is provided between the first conductive circuit layer 60 and the second conductive circuit layer 90, and the patterned insulating layer 30 includes a first pattern 32 and a groove 35 formed between the first patterns, wherein the groove 67 of the first conductive circuit layer 60 and the groove 92 of the second conductive circuit layer 90 are connected to the groove 35 of the patterned insulating layer 30, and the patterned insulating layer 30 is formed by a photosensitive resin, and the groove 32 of the patterned insulating layer 30 is formed by exposing the photosensitive resin and then developing it. In this embodiment, the thickness of the patterned insulating layer is between 5 and 40 microns.

[0052] As can be seen from the above, the present invention uses a photosensitive development pattern to form a hollow area in the insulating layer, and the insulating layer can be removed to form the hollow area without complicated processing steps. Therefore, it is simpler and less costly than the traditional manufacturing method. In particular, the manufacturing method of the present invention does not require the use of complicated laser cutting, which not only saves energy, but also reduces costs and can greatly improve the production efficiency of the hollow circuit board.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for manufacturing a hollow circuit board, comprising the following steps: Providing a metal layer, the metal layer having an upper surface and a lower surface opposite to the upper surface; forming a patterned insulating layer on the upper surface, wherein the patterned insulating layer includes first patterns and first grooves formed between the first patterns, and the patterned insulating layer is formed of a photosensitive resin; Forming a first patterned dry film photoresist layer and a first non-patterned dry film photoresist layer on the upper and lower surfaces of the patterned insulating layer, respectively, wherein a portion of the first patterned dry film photoresist layer is formed in the first groove, and the first patterned dry film photoresist layer includes a second pattern and a second groove formed between the second patterns; forming a first conductive circuit layer in the second trench; Removing the first patterned dry film photoresist layer and the first non-patterned dry film photoresist layer to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; Forming a second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer on the upper and lower surfaces of the first conductive circuit layer, respectively, wherein a portion of the second non-patterned dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; Etching the metal layer through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected with the first groove and the third groove; and The second non-patterned photoresist dry film and the second patterned photoresist dry film are removed to obtain a hollow circuit board. 2 . The manufacturing method according to claim 1 , wherein the photosensitive resin comprises a photosensitive epoxy resin, a photosensitive polyphenyloxazole or a photosensitive polyimide.

3. The manufacturing method according to claim 1, wherein the method for forming the patterned insulating layer comprises the following steps: forming a photosensitive insulating layer; and The photosensitive insulating layer is exposed, developed and baked in sequence to form the patterned insulating layer. 4 . The manufacturing method according to claim 3 , wherein the photosensitive insulating layer is formed by screen printing, coating, spraying, rolling or lamination.

5. The manufacturing method according to claim 1, wherein the first patterned dry film photoresist layer is formed by attaching a dry film photoresist, and then sequentially exposing and developing the dry film photoresist.

6. The manufacturing method according to claim 1, wherein the first non-patterned dry film photoresist layer is formed by attaching a dry film photoresist, then exposing the entire surface of the dry film photoresist and then developing it.

7. The manufacturing method according to claim 1, wherein the second non-patterned dry film photoresist layer is formed by attaching a dry film photoresist, then exposing the entire surface of the dry film photoresist and then developing it.

8. The manufacturing method according to claim 1, wherein the second patterned dry film photoresist layer is formed by attaching a dry film photoresist, and then sequentially exposing and developing the dry film photoresist.

9. The manufacturing method as claimed in claim 1, wherein the thickness of the metal layer is between 12 and 72 micrometers.

10. The manufacturing method according to claim 1, wherein the thickness of the patterned insulating layer is between 5 and 40 microns.

11. A method for manufacturing a hollow circuit board, comprising the following steps: A layered structure is provided, comprising: A first non-patterned dry film photoresist layer; A metal layer disposed on the first non-patterned dry film photoresist layer; A patterned insulating layer, which is disposed on the metal layer, and the patterned insulating layer includes a first pattern and a first groove formed between the first patterns, and the patterned insulating layer is formed of a photosensitive resin; A first patterned dry film photoresist layer, a portion of the first patterned dry film photoresist layer is disposed in the first groove, and the first patterned dry film photoresist layer includes a second pattern and a second groove formed between the second patterns; and A first conductive circuit layer, which is disposed in the second groove; Removing the first patterned dry film photoresist layer and the first non-patterned dry film photoresist layer to expose the space formed after the second pattern is removed and to expose the lower surface of the metal layer; A second non-patterned dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third groove formed between the third patterns, and the third groove corresponds to the first groove; Etching the metal layer through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer is provided with a fourth groove, and the fourth groove is connected with the first groove and the third groove; and The second non-patterned photoresist dry film and the second patterned photoresist dry film are removed to obtain a hollow circuit board.

12. A hollow circuit board, comprising: A first conductive circuit layer having grooves; A second conductive circuit layer having grooves; and A patterned insulating layer is disposed between the first conductive circuit layer and the second conductive circuit layer, and the patterned insulating layer is provided with a groove. The grooves of the first conductive circuit layer and the grooves of the second conductive circuit layer are connected to the grooves of the patterned insulating layer. The patterned insulating layer is formed of a photosensitive resin, and the grooves of the patterned insulating layer are formed by exposing the photosensitive resin and then developing it. 13 . The hollow circuit board as claimed in claim 12 , wherein the thickness of the patterned insulating layer is between 5 and 40 microns.

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