TWI767585B - Manufacturing method of circuit board circuit structure with through hole and circuit board circuit structure with through hole manufactured thereof - Google Patents

Abstract

A manufacturing method of circuit board circuit structure with through hole includes providing a substrate. The substrate includes a substrate layer and two copper layers. The substrate layer has opposite first and second surfaces. The two copper layers are respectively formed on the first of the substrate layer. Surface and second surface; drill holes from the surface of the copper layer on one side of the first surface, and the holes penetrate the substrate; cover the two first photoresist layers on the surface of the two copper layers, so that each first photoresist layer forms a first pattern structure; removing the surface of each copper layer not covered by each first photoresist layer; removing two first photoresist layers; forming a metal layer through chemical reaction, the metal layer covering the substrate; covering two second photoresist layers on each On the surface of the copper layer, each second photoresist layer is formed into a second pattern structure; a copper clad layer is formed by electroplating, and the copper clad layer covers the surface of the hole and stops at the second photoresist layer; removes the two second photoresist layers; remove the metal layer.

Description

Manufacturing method of circuit board circuit structure with via holes and circuit board circuit structure with via holes

A method for manufacturing a circuit board with via holes, in particular a method for fabricating a circuit board structure and the manufactured circuit board structure with via holes.

In the traditional plating process, when conducting hole electroplating at the via hole, the electroplating layer is prone to overflow from the opening of the hole, and a protrusion is formed around the opening of the hole. During circuit fabrication, in order to effectively cover the protrusion, The thickness of the photoresist cannot be thinned, resulting in limited resolution and etching, which affects the production of thin circuit structures on circuit boards.

In view of this, the present application provides, in one embodiment, a method for fabricating a circuit board structure with via holes, including providing a substrate, the substrate includes a base material layer and two copper layers, and the base material layer has opposite first surfaces and second surfaces , two copper layers are respectively formed on the first surface and the second surface of the base material layer; drilling is carried out from the surface of the copper layer on one side of the first surface, and the holes penetrate through the substrate; two first photoresist layers are covered on the two copper layers The surface of the layers, each first photoresist layer forms a first pattern structure; remove the surface of each copper layer that is not covered by each first photoresist layer; remove the two first photoresist layers; form a metallization layer through chemical reaction , the metallization layer covers the substrate; covers two second photoresist layers on the surface of each copper layer, so that each second photoresist layer forms a second pattern structure; forms a copper clad layer through electroplating, and the copper clad layer covers the surface of the hole and Stop at the second photoresist layer; remove the two second photoresist layers; remove the metallization layer outside the copper clad layer.

In some embodiments, the first photoresist layer and the second photoresist layer are dry film photoresist.

In some embodiments, the at least one hole is formed by a laser drilling method.

In some embodiments, the metallization layer is formed by a low stress metallization system.

In some embodiments, the first pattern structure has at least one ear, and the at least one ear surrounds the at least one hole.

In some embodiments, the second pattern structure has at least one notch portion, and an edge of the at least one notch portion substantially corresponds to an edge of the at least one ear portion.

In addition, in another embodiment, the present application provides a circuit board circuit structure with via holes, which is a circuit board circuit structure manufactured by the manufacturing methods of the above-mentioned embodiments.

To sum up, the pattern formed by the photoresist layer can effectively prevent the holes from overflowing the holes during electroplating, and the photoresist layer can be easily removed without affecting the fabrication efficiency of the circuit board structure.

Please refer to FIGS. 1 to 11 first. FIGS. 1 to 8 are schematic structural diagrams (1) to (8) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment of the present invention, and FIG. 11 is the present invention The flow chart of the manufacturing method of the circuit board structure with the via hole according to the one embodiment. As shown in FIG. 1 and FIG. 11 , the manufacturing method of the circuit board circuit structure 100 with via holes of the present embodiment includes providing a substrate 10 (step S10 ). The substrate 10 includes a base material layer 11 and two copper layers 12 . The base material layer 11 has a first surface 111 and a second surface 112 opposite to each other, and two copper layers 12 are respectively formed on the first surface 111 and the second surface 112 of the base material layer 11 . That is, the first surface 111 and the second surface 112 of the substrate layer 11 can be used to manufacture the circuit board structure 100 of the same or different specifications at the same time, or only one side surface can be used to manufacture the circuit board structure 100 . In this embodiment, the circuit board circuit structure 100 is fabricated on double-sided surfaces as an example, but not limited thereto.

As shown in FIG. 2 and FIG. 11 , for the convenience of subsequent description, the copper layer formed on the first surface 111 side is represented by the copper layer 12a, and the copper layer on the second surface 112 side is represented by the copper layer 12b. Drilling is performed from the surface of the copper layer 12 a on one side of the first surface 111 (step S11 ), and at least one hole 20 formed by the drilling will penetrate through the substrate 10 . In this embodiment, at least one hole 20 is formed by means of laser drilling. Here, two holes 20 are taken as an example, but not limited thereto. The holes 20 pass through the copper layer 12a, the base material layer 11 and the copper layer 12b in sequence from the copper layer 12a on one side of the first surface 111 to the copper layer 12b on the one side of the second surface 112 to form through holes.

As shown in FIG. 3 and FIG. 11 , the surfaces of the two first photoresist layers 13 are covered on the two copper layers 12 , and each first photoresist layer 13 is formed into a first pattern structure 131 through exposure and development (step S12 ). Among them, covering the photoresist layer and forming the pattern structure through the exposure and development process is applied to the circuit board photolithography process, by laminating the dry film photoresist to form the photoresist layer, and then using positive photoresist or negative photoresist technology. , to form the required pattern structure (described in detail later). In this embodiment, dry film photoresist is taken as an example.

Subsequently, an etching process is performed to remove the surfaces of the copper layers 12 not covered by the first photoresist layers 13 (step S13 ); as shown in FIG. 3 , after the etching process, the surfaces of the copper layers 12 not covered by the first photoresist layers 13 are The covered two copper layers 12 will be removed from the substrate 10 , and only the two copper layers 12 on which the first pattern structure 131 is to be formed remain.

Next, as shown in FIG. 4 and FIG. 11 , the two first photoresist layers 13 are removed (step S14 ). As can be seen from FIG. 4 , after the two first photoresist layers 13 are removed, there will be formed The required first pattern structure 131 is the second copper layer 12 .

In the traditional process method, the holes are generally plated first and then the circuit is fabricated. After the holes 20 are formed by drilling, the dry film photoresist is used first to form the two copper layers 12 with the first pattern structure 131. The required circuit has better circuit analysis and etching capabilities, and can perform thin-line circuit formation.

Next, as shown in FIG. 4 and FIG. 11 , the metallization layer 14 is formed through a chemical reaction (step S15 ), and the metallization layer 14 covers the substrate 10 . In this embodiment, the metallization layer is formed by a low stress metallization system. In this embodiment, the metallization layer 14 of the substrate 10 is formed and covered by a low-stress metallization system. Specifically, different from the conventional process method, the low-stress metallization system will make the metallization layer 14 fully cover the substrate. 10. The covered area includes the surface of the hole 20, and the surface of the hole 20 includes the hole wall 21, and the hole wall 21 includes the exposed copper layer 12a, the base material layer 11 and the copper layer 12b through drilling. In addition, the coverage of the metallization layer 14 also includes the surfaces of the remaining exposed substrate layers 11 and the surfaces of the two copper layers 12 .

As shown in FIG. 5 and FIG. 11 , two second photoresist layers 15 are covered on the surface of each copper layer 12 , and through exposure and development, each second photoresist layer 15 is formed into a second pattern structure 151 (step S16 ). In this embodiment, the first pattern structure 131 and the second pattern structure 151 cooperate with each other, the first pattern structure 131 has an ear portion 132, the ear portion 132 surrounds the hole 20, the second pattern structure 151 has a notch portion 152, the notch portion The edge of 152 roughly corresponds to the edge of the ear portion 132 . Specifically, the side edge of the notch portion 152 is flush with the side edge of the ear portion 132 to form a structure similar to a step (described in detail later) for subsequent electroplating.

As shown in FIG. 6 and FIG. 11 , the copper clad layer 16 is formed by electroplating (step S17 ). The copper clad layer 16 covers the surface of the hole 20 and ends at the second photoresist layer 15 . In this embodiment, the surface of the hole 20 is formed and covered by electroplating, and the covered area includes the side surfaces of the copper layer 12a, the base layer 11 and the copper layer 12b exposed by drilling. In addition, in this embodiment, the copper clad layer 16 extends along the stepped structure formed by the ear portion 132 and the notch portion 152 and covers the surface of the ear portion 132 , and the copper clad layer is blocked by the second photoresist layer 15 . 16 ends at the second photoresist layer 15 and does not extend further.

As shown in FIG. 7 and FIG. 11 , after the electroplating is completed, the two second photoresist layers 15 are removed (step S18 ). As can be seen from FIG. 7 , after the two second photoresist layers 15 are removed, the copper clad layer 16 extending to the surface of the ear portion 132 along the aforementioned stepped structure is left on the substrate 10 .

The first pattern structure 131 makes the copper layer 12 form a multi-segment structure, and forms an ear portion 132 around the opening of the hole 20 , and the second pattern structure 151 cooperates with the ear portion 132 formed by the first pattern structure 131 , a stepped structure is formed, and the copper clad layer 16 extends along the aforementioned stepped structure and is blocked by the second pattern structure 151 to achieve the effect of preventing the electroplating layer from overflowing the holes.

As shown in FIG. 8 and FIG. 11 , a chemical etching process is performed to remove the metallization layer 14 other than the copper clad layer 16 (step S19 ). Here, the metallization layer 14 removed by chemical etching is the metallization layer 14 outside the range of the copper clad layer 16 .

In addition, in this embodiment, the circuit board circuit structure 100 is made of a double-sided board with only one base material layer 11 and two copper layers 12, but it is not limited to this, and may also have more base material layers 11, and The copper layer 12 increases with the increase of the base material layer 11 , that is, the copper layer 12 is made of a multilayer board in which the multiple base material layers 11 and the multiple copper layers 12 are stacked. For example, the order of the layers of the multilayer board from top to bottom can be, for example, copper layer, base material layer, copper layer, base material layer, copper layer, base material layer and copper layer, and this multilayer board is used for the fabrication of circuit board circuit structure . In this embodiment, the base material layer 11 may be any pure metal material or composite metal material.

Please refer to Figure 9 and Figure 10. In another embodiment, the holes 30 are connected to the substrate 10 to form blind vias. Parts that are the same as those in the above-mentioned embodiments will not be repeated, and only some differences will be described. Drilling is performed from the surface of the copper layer 12 a on one side of the first surface 111 , and the holes 30 formed by the drilling are conducted to the second surface 112 of the base material layer 11 . The holes 30 are formed from the copper layer 12a on one side of the first surface 111 through the copper layer 12a to the second surface 112 of the base material layer 11 to form via holes. In the chemical reaction stage, the metallization layer 14 covers the surface of the hole 30, and the surface of the hole 30 includes the hole wall 31 and the hole bottom 32. The hole wall 31 includes the exposed copper layer 12a and the base material layer 11, and the hole bottom 32 is the surface of the copper layer 12b bonded to the second surface 112 of the base material layer 11 . In addition, the metallization layer 14 also covers the other exposed surfaces of the base material layer 11 and the surfaces of the two copper layers 12 . In the electroplating stage, the copper clad layer 16 covers the surface of the hole 30 and extends to one side of the first surface 111 , and stops at the second photoresist layer 15 as shown in FIG. 6 . After the second photoresist layer 15 is removed, the circuit board circuit structure 100 with via holes as shown in FIG. 10 is completed.

To sum up, according to an embodiment of a method for fabricating a circuit board structure with via holes, the first photoresist layer 13 and the second photoresist layer 15 are used to increase the coverage of the metallization layer 14 and the copper clad layer 16 The copper clad layer 16 extends along the stepped structure formed by the cooperation of the first pattern structure 131 and the second pattern structure 151, and is blocked by the second photoresist layer 15, so that the copper clad layer 16 is attached to the first pattern structure. 131 on the copper layer 12, so as to avoid the electroplating layer overflowing from the hole and forming the electroplating layer protrusion around the hole when the hole is electroplated. The circuit board circuit structure 100 with via holes completed by the method of this application includes a base material layer 11 , two copper layers 12 and a copper clad layer 16 . The copper clad layer 16 covers the holes 20 , and the copper clad layer 16 is along the ears. 132 extends to the surface of the two copper layers 12, and because of the blocking of the second photoresist layer 15, the extension of the copper clad layer 16 does not exceed the portion of the ear portion 132, so that the substrate 10 has a more flat surface.

Although the technical content of this case has been disclosed above with preferred embodiments, it is not intended to limit this case. Anyone who is familiar with this technique, any changes and modifications made without departing from the spirit of this case should be covered within the scope of this case. Therefore, the scope of protection in this case should be determined by the scope of the appended patent application.

100: Circuit board structure 10: Substrate 11: Substrate layer 111: First surface 112: Second Surface 12: Copper layer 12a: Copper layer 12b: Copper layer 13: The first photoresist layer 131: The first pattern structure 132: Ears 14: Metallization layer 15: Second photoresist layer 151: Second pattern structure 152: Notch 16: Copper cladding 20: Holes 21: Hole Wall 30: Holes 31: Hole Wall 32: Bottom of the hole Step S10: providing a substrate Step S11: Drilling from the surface of the copper layer on one side of the first surface Step S12: Covering the surfaces of the two first photoresist layers on the two copper layers, and exposing and developing each of the first photoresist layers to form a first pattern structure Step S13: performing an etching process to remove the surfaces of the copper layers not covered by the first photoresist layers Step S14: removing two first photoresist layers Step S15: forming a metallization layer through chemical reaction Step S16: Covering two second photoresist layers on the surface of each copper layer, and exposing and developing each second photoresist layer to form a second pattern structure Step S17: forming a copper clad layer through electroplating Step S18: removing two second photoresist layers Step S19: perform chemical etching to remove the metallization layer

FIG. 1 is a schematic structural diagram (1) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 2 is a schematic structural diagram (2) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 3 is a schematic structural diagram (3) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 4 is a schematic structural diagram (4) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 5 is a schematic structural diagram (5) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 6 is a schematic structural diagram (6) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 7 is a schematic structural diagram (7) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. FIG. 8 is a schematic structural diagram (8) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. [ FIG. 9 ] is a schematic structural diagram of a manufacturing method of a circuit board structure with a via hole according to another embodiment. 10 is a schematic structural diagram of a method for manufacturing a circuit board circuit structure with vias according to another embodiment. 11 is a flow chart of a method for manufacturing a circuit board circuit structure with vias according to an embodiment.

Step S10: providing a substrate

Step S11: Drilling from the surface of the copper layer on one side of the first surface

Step S12: Covering the surfaces of the two first photoresist layers on the two copper layers, and exposing and developing each of the first photoresist layers to form a first pattern structure

Step S13: performing an etching process to remove the surfaces of the copper layers not covered by the first photoresist layers

Step S14: removing two first photoresist layers

Step S15: forming a metallization layer through chemical reaction

Step S16: Covering two second photoresist layers on the surface of each copper layer, and exposing and developing each second photoresist layer to form a second pattern structure

Step S17: forming a copper clad layer through electroplating

Step S18: removing two second photoresist layers

Step S19: perform chemical etching to remove the metallization layer

Claims (7)

A manufacturing method of a circuit board circuit structure with a via hole, comprising: A substrate is provided, the substrate includes a base material layer and two copper layers, the base material layer has a first surface and a second surface opposite to each other, and the two copper layers are respectively formed on the first surface and the second surface of the base material layer. the second surface; Drilling is carried out from the surface of the copper layer on one side of the first surface to form at least one hole, and the at least one hole penetrates the substrate; Covering two first photoresist layers on the surfaces of the two copper layers, and through exposure and development, each of the first photoresist layers forms a first pattern structure; performing an etching process to remove the surfaces of the copper layers not covered by the first photoresist layers; removing the two first photoresist layers; forming a metallization layer through chemical reaction, the metallization layer covering the substrate; Covering two second photoresist layers on the surface of each of the copper layers, and through exposure and development, each of the second photoresist layers forms a second pattern structure; forming a copper clad layer through electroplating, the copper clad layer covering the surface of the at least one hole and ending at the second photoresist layer; removing the two second photoresist layers; and A chemical bite is performed to remove the metallization outside the copper clad layer. The method for fabricating a circuit board circuit structure with via holes as claimed in claim 1, wherein the first photoresist layer and the second photoresist layer are dry film photoresist. The method for fabricating a circuit board circuit structure with via holes as claimed in claim 1, wherein the at least one hole is formed by a laser drilling method. The method for fabricating a circuit board structure with vias as claimed in claim 1, wherein the metallization layer is formed through a low-stress metallization system. The method for fabricating a circuit board circuit structure with via holes as claimed in claim 1, wherein the first pattern structure has at least one ear portion, and the at least one ear portion surrounds the at least one hole. The method for fabricating a circuit board circuit structure with via holes as claimed in claim 5, wherein the second pattern structure has at least one notch portion, and an edge of the at least one notch portion roughly corresponds to an edge of the at least one ear portion. A circuit board circuit structure with via holes manufactured by the method for manufacturing a circuit board circuit structure with via holes according to any one of claims 1 to 6.

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