TWI747751B - Manufacturing 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 a copper layer. The substrate layer has opposite first and second surfaces. Each copper layer is formed on the first surface and the second surface of the substrate layer; cover the two photoresist layers on the surface of the two copper layers, and through exposure, make each photoresist layer chemical resistant; drill holes from the surface of the photoresist layer on one side of the first surface to form holes, which lead to the second surface of the substrate layer; a metallized layer is formed by chemical method, which covers the surface of the hole and the surface of the photoresist layer on one side of the first surface; a copper clad layer is formed by electroplating, which covers the surface of the hole and extends to the surface of the photoresist layer on one side of the first surface; removal of the copper-clad layer exceeding the height of the copper layer by etching; and the two photoresist layers are removed to complete the subsequent circuit pattern.

Description

Method for manufacturing circuit board circuit structure with through holes and manufactured circuit board circuit structure with through holes

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

The traditional method of selective plating is to perform metallization after drilling and clearing holes, then use dry film masking, use exposure and development to expose the metallized holes, and then electroplating, because both the drilling process and the exposure process exist Due to the problem of process tolerances, the dry film drilling process must be opened according to the drilling position, and equipment with automatic alignment (CCD exposure machine or digital direct drawing exposure machine) must be used, and due to the problem of progressive tolerance The size of the hole must be enlarged to form a protrusion around the hole after electroplating. During circuit production, in order to effectively cover the protrusions, the thickness of the photoresist cannot be thinned, which limits the resolution and etching molding, and affects the production of fine circuits of the circuit board circuit structure.

In view of this, according to an embodiment, a method for manufacturing a circuit board circuit structure with vias is provided. The method includes providing a substrate. The substrate includes a substrate layer and a copper layer. The substrate layer has a first surface and a second surface opposite to each other. Formed on the first surface and the second surface of the substrate layer; cover the two first photoresist layers on the surface of the two copper layers, and through full exposure, make each first photoresist layer have chemical resistance; self-locating on the first surface Drill holes on the surface of the first photoresist layer on one side to form holes, which lead to the second surface of the substrate layer; form a metallization layer by chemical means, and the metallization layer covers the surface of the hole and is located on the first surface The surface of the first photoresist layer on one side; the copper clad layer is formed by electroplating, which covers the surface of the hole and extends to the surface of the first photoresist layer on one side of the first surface; through chemical etching Remove part of the copper clad layer that exceeds the height of the copper layer; remove the two first photoresist layers; cover the two second photoresist layers on the surface of the two copper layers, and through exposure and development, make the two second photoresist layers form a circuit pattern Structure; performing an etching process to remove the surface of each copper layer not covered by each second photoresist layer; and remove two second photoresist layers.

In some embodiments, at least one hole penetrates the substrate.

In some embodiments, the photoresist layer is a dry film photoresist.

In some embodiments, the holes are formed by laser drilling.

In some embodiments, the metallization layer is formed through a neutral or weakly acidic metallization system.

In some embodiments, the two first photoresist layers include thin films, and the thin films are removed after the two first photoresist layers are fully exposed.

In some embodiments, the two first photoresist layers include thin films, and after drilling holes on the surface of the first photoresist layer on one side of the first surface, the thin films are removed.

In some embodiments, the hole has a recess, and the recess surrounds the opening of the hole.

In some embodiments, the copper clad layer extends along the recess to cover the exposed surface of the copper layer on one side of the first surface.

In addition, according to one embodiment, a circuit board circuit structure with vias is provided, which is a circuit board circuit structure manufactured by the manufacturing method of the above-mentioned embodiments.

In summary, the metallization and electroplating range is increased by the first photoresist layer. During the electroplating process, the copper-clad layer extends to the surface of the first photoresist layer, and then removes more than the first photoresist. The copper-clad layer in the height range of the layer and the removal of the first photoresist layer make the height of the electroplated layer and the copper layer roughly the same, avoiding the problem of the electroplated layer overflowing the hole and forming a protrusion around the hole when the hole is electroplated.

Please refer to Figures 1 to 7b and Figure 12. Figures 1 to 7b are structural schematic diagrams (1) to (9) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment of the present invention. Figure 12 is The flow chart (1) of the manufacturing method of the circuit board circuit structure with via holes according to an embodiment of the present invention. As shown in FIGS. 1 and 12, the manufacturing method of the circuit board circuit structure 100 with via holes of this embodiment includes providing a substrate 10 (step S10). The substrate 10 includes a substrate layer 11 and two copper layers 12, and the substrate layer 11 has a first surface 111 and a second surface 112 opposite to each other. Two copper layers 12 are respectively formed on the first surface 111 and the second surface 112 of the base layer 11. In other words, the first surface 111 and the second surface 112 of the substrate layer 11 can be used to fabricate the circuit board circuit structure 100 of the same or different specifications at the same time, or only a single side surface can be used to fabricate the circuit board circuit structure 100. In this embodiment, a single side surface is used to fabricate the circuit board circuit structure 100 as an example, but it is not limited to this.

As shown in Figures 2 and 12, the two first photoresist layers 13 are covered on the surface of the two copper layers 12, and through full exposure, each first photoresist layer 13 has chemical resistance (step S11); The first photoresist layer 13 is fully exposed through an existing process, for example, applied to a circuit board photolithography process, a photoresist layer is formed by laminating a dry film photoresist or a photoresist layer is formed by coating a wet film photoresist. In this embodiment, a dry film photoresist is taken as an example, and the photoresist is formed into a chemically resistant state by means of full exposure.

As shown in FIG. 3 and FIG. 12, for the convenience of subsequent description, the first photoresist layer on the side of the first surface 111 is indicated by the first photoresist layer 13a, and the first photoresist layer on the side of the second surface 112 is indicated by The first photoresist layer 13b is schematically shown. The copper layer formed on the side of the first surface 111 is indicated by a copper layer 12a, and the copper layer formed on the side of the second surface 112 is indicated by a copper layer 12b. Drilling is performed from the surface of the first photoresist layer 13a located on one side of the first surface 111 (step S12) to form a hole 20, and the hole 20 is conducted to the second surface 112 of the substrate layer 11. In this embodiment, the hole 20 is formed by laser drilling. Here, two holes 20 are taken as an example, but not limited thereto. The hole 20 is formed from the first photoresist layer 13a on one side of the first surface 111 to the copper layer 12b on one side of the second surface 112 through the first photoresist layer 13a, the copper layer 12a and the substrate layer 11 in sequence Pilot hole. The hole 20 includes a hole wall 21 and a hole bottom 22. The hole wall 21 includes a first photoresist layer 13 a, a copper layer 12 a and a side surface of the base material layer 11 that are drilled and exposed. The bottom 22 of the hole includes the surface of the copper layer 12 b bonded to the second surface 112.

As shown in FIGS. 4 and 12, the metallization layer 14 is formed by a chemical method (step S13 ), and the metallization layer 14 covers the surface of the hole 20 and the surfaces of the two first photoresist layers 13. In this embodiment, the photoresist layer is formed by using dry film photoresist. The traditional dry film photoresist such as contacting alkaline metallization system will cause the dry film photoresist structure to be damaged or even fall off, so it is implemented here In an example, the metallization layer 14 is formed by a neutral or weakly acidic metallization system. In this embodiment, the surface of the hole 20 and the surface of the two first photoresist layers 13 are formed and covered by a chemically neutral or weakly acidic metallization system. That is to say, the metallization layer 14 covers the surface of the first photoresist layer 13a on the side of the first surface 111 and the surface of the first photoresist layer 13b on the side of the second surface 112. Generally, the coverage of the metallization layer 14 does not include the metal material, such as the side surface of the copper layer 12a exposed by drilling and the surface of the copper layer 12b exposed by the drilling.

As shown in FIGS. 5 and 12, after the metallization layer 14 is formed, a copper-clad layer 15 is formed by electroplating (step S14). The copper-clad layer 15 covers the surface of the hole 20 and extends to the first surface on one side of the first surface 111. The surface of a photoresist layer 13a. In this embodiment, the surface of the hole 20 is formed and covered by electroplating, that is, the side surfaces of the first photoresist layer 13a, the copper layer 12a, and the base layer 11 exposed by drilling. In addition, in this embodiment, because of the copper layer 12b on the side of the second surface 112, the copper clad layer 15 can extend to the surface of the first photoresist layer 13a on the side of the first surface 111.

As shown in FIGS. 6 and 12, after the electroplating is completed, the copper-clad layer 15 whose part exceeds the height of the copper layer 12a on one side of the first surface 111 is removed by chemical etching (step S15). For example, in this embodiment, in order to make the height of the copper-clad layer 15 and the copper layer 12a roughly the same, the part of the copper-clad layer 15 that exceeds the copper layer 12a on one side of the first surface 111 is removed by chemical biting. The height of the copper clad layer 15 is higher than the height of the copper layer 12a and lower than the height of the first photoresist layer 13a. As shown in FIG. 7 and FIG. 12, after the chemical bite etching is completed, the two first photoresist layers 13 are removed (step S16), and the pattern of each subsequent circuit is continued to be produced. As shown in FIG. 7a, FIG. 7b and FIG. 12, the two second photoresist layers 16 are covered on the surface of the two copper layers 12, and through exposure and development, the two second photoresist layers 16 form a circuit pattern structure 161 (step S17). An etching process is performed to remove the surface of each copper layer 12 not covered by each second photoresist layer 16 (step S18). Then, the two second photoresist layers 16 are removed (step S19), and the circuit board circuit structure 100 is completed.

Specifically, the metallization and electroplating range is increased by the two first photoresist layers 13. During the electroplating process, the copper-clad layer 15 extends to the surface of the first photoresist layer 13a, and then is removed together beyond the first photoresist layer 13a. The copper-clad layer 15 with the height range of the photoresist layer 13a and the removal of the two first photoresist layers 13 make the copper-clad layer 15 and the copper layer 12a approximately the same height, which prevents the electroplated layer from overflowing the hole when the hole is electroplated. Problems forming protrusions.

In addition, please refer to Figure 2a, Figure 12a and Figure 12b. FIG. 2a is a schematic diagram of a film of a circuit board circuit structure with via holes according to an embodiment. Fig. 12a is a flowchart (2) of a manufacturing method of a circuit board circuit structure with via holes according to an embodiment. Fig. 12b is a flow chart (3) of a manufacturing method of a circuit board circuit structure with via holes according to an embodiment. Generally speaking, there is a layer of optical-grade polyethylene terephthalate (PET) film on the surface of the dry film, which can protect the dry film from reacting when exposed to air. In the general manufacturing process, it is used before development. The PET film will be removed. As shown in Figure 12a, in this embodiment, the substrate 10 is fully exposed but not developed. Therefore, the substrate 10 is covering the surface of the two first photoresist layers 13 on the two copper layers 12, and through the full exposure, the first After the photoresist layer 13 has chemical resistance (step S11), the polyethylene terephthalate film 131 is removed (step S11'), and then from the first photoresist layer 13a on one side of the first surface 111 Drill holes on the surface (step S12), but not limited to this. As shown in FIG. 12b, in another embodiment, the substrate 10 is after covering the surface of the two first photoresist layers 13 on the two copper layers 12, and through full exposure, so that each first photoresist layer 13 has chemical resistance After (step S11), drill holes from the polyethylene terephthalate film 131 on the surface of the first photoresist layer 13a on one side of the first surface 111 (step S12a), and then remove the polyethylene terephthalate The ethylene glycol film 131 (step S12a'). In another embodiment, a wet film photoresist is taken as an example. Since there is no PET film in the wet film photoresist, there is no need to remove the PET film.

In addition, in this embodiment, the circuit board circuit structure 100 is suitable for, for example, a double-sided board or an initial inner board of a multilayer board. Here, a double-sided board with a base material layer 11 and two copper layers 12 is used as an example. Specifically, this embodiment uses a neutral or weakly acidic metallization system for metallization. For example, for neutral or weakly acidic metallization, the bottom layer of the substrate needs to be fully conductive. However, the production of multi-layer boards is gradually Layer overlay. When the outer board of the multilayer board is manufactured, the inner board cannot be fully conductive because the inner board has already been manufactured. Therefore, the circuit board circuit structure 100 of this embodiment is suitable for the inner board of a double-sided board or a multilayer board, for example. In this embodiment, the substrate layer 11 may be any pure metal material or composite metal material.

Refer to Figure 8. FIG. 8 is a schematic structural diagram (1) of another embodiment of a manufacturing method of a circuit board circuit structure with via holes. In another embodiment, the hole 20 has a recess 201, and the recess 201 surrounds the opening of the hole 20. For example, during the laser processing process, the first photoresist layer 13a may shrink due to the thermal effect of the laser processing, or the aperture of the first photoresist layer 13a may be deliberately larger than the aperture of the hole 20. At this time, the copper A step structure is formed between the layer 12a and the first photoresist layer 13a. Refer to Figure 9. FIG. 9 is a schematic structural diagram (2) of another embodiment of a manufacturing method of a circuit board circuit structure with via holes. After the metallization layer 14 is formed, the copper-clad layer 15 is formed by electroplating (step S14). The copper-clad layer 15 covers the surface of the hole 20 and extends to the surface of the first photoresist layer 13a located on one side of the first surface 111. The copper-clad layer 15 covers the surface of the hole 20, that is, the side surfaces of the first photoresist layer 13a, the copper layer 12a, and the substrate layer 11 exposed by drilling, and also covers the first photoresist layer 13a due to laser processing. The surface of the copper layer 12a that is retracted and exposed. After electroplating, the copper clad layer 15 beyond the copper layer 12a on one side of the first surface 111 is removed by chemical etching, so that the height of the copper clad layer 15 is higher than that of the copper layer 12a and lower than the height of the first photoresist layer 13a (Step S15). As shown in FIG. 9, the copper-clad layer 15 forms ears around the opening of the hole 20, which increases the contact area between the copper-clad layer 15 and the copper layer 12a, and strengthens the performance of reliability.

Please refer to Figure 10, Figure 10a and Figure 11. FIG. 10 is a schematic structural diagram (1) of a manufacturing method of a circuit board circuit structure with via holes according to another embodiment. Fig. 10a is a schematic structural diagram (2) of another embodiment of a method for fabricating a circuit board circuit structure with vias. FIG. 11 is a schematic diagram (3) of another embodiment of a method for manufacturing a circuit board circuit structure with vias. In another embodiment, at least one hole 30 penetrates the substrate 10 to form a through hole. Some parts that are the same as those in the above-mentioned embodiment will not be repeated, and only some of the differences will be described. As shown in FIG. 10, a hole 30 is formed by laser drilling. The hole 30 passes through the first photoresist layer 13a on one side of the first surface 111 to the first photoresist layer 13b on one side of the second surface 112 in order. The first photoresist layer 13a, the copper layer 12a, the base layer 11, the copper layer 12b, and the first photoresist layer 13b are formed. The hole 30 includes a hole wall 31 which includes the side surfaces of the first photoresist layer 13a, the copper layer 12a, the base material layer 11, the copper layer 12b, and the first photoresist layer 13b that are drilled and exposed. The metallization layer 14 covers the surface of the hole 30, the surface of the first photoresist layer 13a on one side of the first surface 111, and the surface of the first photoresist layer 13b on one side of the second surface 112. Generally, the coverage of the metallization layer 14 does not include the metal material, such as the side surface of the copper layer 12a exposed by drilling and the side surface of the copper layer 12b exposed by the drilling. As shown in FIG. 10a, during the electroplating stage, the copper-clad layer 15 covers the surface of the hole 30 and extends to the first surface of the first photoresist layer 13a located on one side of the first surface 111 and one side of the second surface 112. The surface of the photoresist layer 13b. As shown in FIG. 11, the copper clad layer 15 that partially exceeds the height of the copper layer 12a located on one side of the first surface 111 and the portion of the copper clad layer 15 that exceeds the height of the copper layer 12b located on one side of the second surface 112 is then removed by chemical etching.铜层15。 Copper layer 15. After removing the first photoresist layer 13, the substrate 10 with through holes as shown in FIG. 11 is completed.

In summary, according to an embodiment of the method for fabricating a circuit board circuit structure with via holes, the metallization and electroplating range is increased by the two first photoresist layers 13. When the electroplating process is performed, the copper-clad layer 15 extends to the surface of the first photoresist layer 13a, and then removes the copper clad layer 15 that exceeds the height range of the first photoresist layer 13a and removes the two first photoresist layers 13, so that the copper clad layer 15 and the copper layer 12a The height is approximately the same, which prevents the electroplating layer from overflowing the hole when the hole is electroplated, forming a protrusion around the hole, which affects the production of the circuit board circuit structure 100. The circuit board circuit structure 100 with via holes completed by the method of one embodiment of the present case includes a substrate layer 11, two copper layers 12 and a copper clad layer 15. The copper clad layer 15 covers the hole 20 and is located at the opening of the hole 20 There is a relatively flat copper clad layer 15 around, so that the overall surface of the substrate 10 is flatter. In addition, the circuit board circuit structure 100 with via holes completed by the method of another embodiment of the present application includes a substrate layer 11, two copper layers 12, and a copper clad layer 15. The copper clad layer 15 covers the hole 20, and the copper clad layer 15 extends to the opening of the hole 20 and forms an ear around the opening of the hole 20. The recess 201 of the hole 20 increases the contact area between the copper-clad layer 15 and the copper layer 12a, and strengthens the performance of reliability.

Although the technical content of this case has been disclosed in a preferred embodiment as above, it is not intended to limit the case. Anyone who is familiar with this technique and makes slight changes and modifications without departing from the spirit of the case should be included in the scope of this case. Therefore, the scope of protection in this case shall be subject to the scope of the attached patent application.

100: Circuit board circuit 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 13a: The first photoresist layer 13b: The first photoresist layer 131: Polyethylene terephthalate film 14: Metallization layer 15: Copper layer 16: second photoresist layer 161: Line pattern structure 20: Hole 201: recess 21: Hole Wall 22: Hole bottom 30: Hole 31: Hole Wall Step S10: Provide substrate Step S11: Cover the two first photoresist layers on the surface of the two copper layers, and make each first photoresist layer have chemical resistance through full exposure Step S11’: Remove the polyethylene terephthalate film Step S12: Drill holes from the surface of the first photoresist layer located on one side of the first surface Step S12a: Drill holes from the polyethylene terephthalate film on the surface of the first photoresist layer on one side of the first surface Step S12a’: Remove the polyethylene terephthalate film Step S13: Form metallization layer by chemical method Step S14: forming a copper clad layer by electroplating Step S15: Remove the copper-clad layer that partially exceeds the height of the copper layer on one side of the first surface by chemical biting Step S16: Remove the second photoresist layer Step S17: Cover the two second photoresist layers on the surface of the two copper layers, and through exposure and development, make the two second photoresist layers form a circuit pattern structure Step S18: Perform an etching process to remove the surface of each copper layer not covered by each second photoresist layer Step S19: Remove the second photoresist layer

[Figure 1] is a schematic structural diagram (1) of a manufacturing method of a circuit board circuit structure with via holes according to an embodiment. [Figure 2] is a schematic diagram (2) of an embodiment of a method for manufacturing a circuit board circuit structure with vias. [Figure 2a] is a schematic diagram of a film of a circuit board circuit structure with via holes in an embodiment. [Fig. 3] is a schematic diagram (3) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. [Figure 4] is a schematic diagram (4) of an embodiment of a manufacturing method of a circuit board circuit structure with via holes. [Figure 5] is a schematic diagram (5) of an embodiment of a method for manufacturing a circuit board circuit structure with vias. [Figure 6] is a schematic diagram (6) of an embodiment of a method for manufacturing a circuit board circuit structure with vias. [FIG. 7] A schematic diagram (7) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. [Fig. 7a] is a schematic structural diagram (8) of a manufacturing method of a circuit board circuit structure with via holes according to an embodiment. [Fig. 7b] is a schematic diagram (9) of a method for manufacturing a circuit board circuit structure with via holes according to an embodiment. [Figure 8] is a schematic diagram (1) of another embodiment of the method for fabricating a circuit board circuit structure with vias. [Fig. 9] is a schematic diagram (2) of another embodiment of a method for manufacturing a circuit board circuit structure with vias. [Figure 10] is a schematic diagram (1) of another embodiment of a method for manufacturing a circuit board circuit structure with vias. [Figure 10a] is a schematic diagram (2) of another embodiment of the method for manufacturing a circuit board circuit structure with vias. [FIG. 11] is a schematic diagram (3) of another embodiment of a method for manufacturing a circuit board circuit structure with vias. [Fig. 12] is a flow chart (1) of a manufacturing method of a circuit board circuit structure with via holes according to an embodiment. [Figure 12a] is a flow chart (2) of an embodiment of a method for manufacturing a circuit board circuit structure with vias. [Figure 12b] is a flow chart (3) of an embodiment of a method for manufacturing a circuit board circuit structure with vias.

Step S10: Provide substrate

Step S11: Cover the two first photoresist layers on the surface of the two copper layers, and make each first photoresist layer have chemical resistance through full exposure

Step S12: Drill holes from the surface of the first photoresist layer located on one side of the first surface

Step S13: Form metallization layer by chemical method

Step S14: forming a copper clad layer by electroplating

Step S15: Remove the copper-clad layer that partially exceeds the height of the copper layer on one side of the first surface by chemical biting

Step S16: Remove the second photoresist layer

Step S17: Cover the two second photoresist layers on the surface of the two copper layers, and through exposure and development, make the two second photoresist layers form a circuit pattern structure

Step S18: Perform an etching process to remove the surface of each copper layer not covered by each second photoresist layer

Step S19: Remove the second photoresist layer

Claims (10)

A method for manufacturing a circuit board circuit structure with through holes includes: providing a substrate, the substrate including a substrate layer and two copper layers, the substrate layer has a first surface and a second surface opposite to each other, each of the copper The layer is formed on the first surface and the second surface of the substrate layer; covers the two first photoresist layers on the surface of the two copper layers, and through full exposure, makes each of the first photoresist layers have chemical resistance Drilling from the surface of the first photoresist layer on one side of the first surface to form at least one hole, the at least one hole is conducted to the second surface of the substrate layer; forming a metal by chemical means The metallization layer covers the surface of the at least one hole and the surface of the two first photoresist layers; a copper clad layer is formed by electroplating, and the copper clad layer covers the surface of the at least one hole and extends to The surface of the first photoresist layer on one side of the first surface; removing part of the copper-clad layer that exceeds the height of the copper layer by chemical biting, so that the copper-clad layer and the height of the copper layer are substantially aligned; Remove the two first photoresist layers; cover the two second photoresist layers on the surface of the two copper layers, and through exposure and development, make the two second photoresist layers form a circuit pattern structure; perform an etching process to remove undesirable The surface of each copper layer covered by each of the second photoresist layers; and removing the two second photoresist layers. The method for fabricating a circuit board circuit structure with vias according to claim 1, wherein the at least one hole penetrates the substrate. The manufacturing method of the circuit board circuit structure with via holes according to claim 1, wherein the first photoresist layer and the second photoresist layer are dry film photoresists. The method for manufacturing a circuit board circuit structure with via holes as described in claim 1, wherein the at least one hole is formed by a laser drilling method. The method for manufacturing a circuit board circuit structure with via holes according to claim 1, wherein the metallization layer is formed by a neutral or weakly acidic metallization system. The method for manufacturing a circuit board circuit structure with via holes according to claim 3, wherein the two first photoresist layers include a thin film, and the thin film is removed after the two first photoresist layers are fully exposed. The method for manufacturing a circuit board circuit structure with via holes according to claim 3, wherein the two first photoresist layers include a thin film, and the surface of the first photoresist layer on one side of the first surface is drilled ,Remove the film. The method for manufacturing a circuit board circuit structure with vias according to claim 1, wherein the at least one hole has a recess, and the recess surrounds the opening of the at least one hole. The method for manufacturing a circuit board circuit structure with vias according to claim 8, wherein the copper clad layer extends along the recess to cover the exposed surface of the copper layer on one side of the first surface direction. A circuit board circuit structure manufactured by the method for manufacturing a circuit board circuit structure with via holes according to any one of claims 1 to 9.

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