CN112118688A

CN112118688A - Process for increasing layer of back-adhesive copper foil

Info

Publication number: CN112118688A
Application number: CN201910548162.1A
Authority: CN
Inventors: 李家铭
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2020-12-22

Abstract

The invention provides a layer increasing process of a back-adhesive copper foil, which comprises the following steps: (1) providing a substrate circuit board, wherein the substrate circuit board is provided with an additional layer surface, and the additional layer surface is provided with a first circuit layer; (2) attaching an original coiled back-adhesive copper foil to the surface of the build-up layer in a vacuum film pressing mode, wherein the back-adhesive copper foil is provided with a copper foil layer and an insulating adhesive layer, the insulating adhesive layer is coated on the copper foil layer, and the first circuit layer contacts with the insulating adhesive layer but does not contact with the copper foil layer; (3) electroplating a copper electroplating layer on the copper foil layer; and (4) patterning the copper foil layer and the electroplated copper layer into a second circuit layer. Therefore, the layer increasing efficiency of the circuit board is greatly improved.

Description

Process for increasing layer of back-adhesive copper foil

Technical Field

The present invention relates to a circuit board technology, and more particularly, to a build-up layer technology of a circuit board.

Background

With the popularization of electronic products, the application of circuit substrates is becoming wider and wider, and the circuit design tends to be complicated and multilayered, so in the past, a plurality of polypropylene plates with copper foils formed on one side or two sides are laminated to increase the layers, however, the plate-to-plate laminating and layer increasing mode in the prior art is not easy to manufacture, and has higher cost and needs to be improved.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a method for increasing the layer by using a film-attaching method.

In order to achieve the above and other objects, the present invention provides a process for increasing the layer of an adhesive-backed copper foil, which comprises:

(1) providing a substrate circuit board, wherein the substrate circuit board is provided with an additional layer surface, and the additional layer surface is provided with a first circuit layer;

(2) attaching an original coiled back-adhesive copper foil to the surface of the build-up layer in a vacuum film pressing mode, wherein the back-adhesive copper foil is provided with a copper foil layer and an insulating adhesive layer, the insulating adhesive layer is coated on the copper foil layer, and the first circuit layer contacts with the insulating adhesive layer but does not contact with the copper foil layer;

(3) electroplating a copper electroplating layer on the copper foil layer; and

(4) and patterning the copper foil layer and the electroplated copper layer into a second circuit layer.

According to the invention, the copper foil layer and the insulating adhesive layer are formed and rolled in advance, and then the original rolled back adhesive copper foil is attached to the lamination surface in a vacuum film pressing mode to perform lamination, so that the lamination efficiency can be greatly improved, the lamination process is simplified, and the problem of laminating and laminating by using plates in the past is solved.

Other effects and embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 to fig. 2 are schematic diagrams illustrating steps of a build-up process of an adhesive-backed copper foil according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of an adhesive-backed copper foil;

FIG. 4 is a schematic view of a vacuum lamination apparatus;

fig. 5 to 8 are schematic views illustrating steps of a process for increasing the layer of the copper foil with adhesive according to one embodiment of the present invention.

Description of the symbols

10-

substrate circuit board

11A, 11B build-up surface

12A, 12B first circuit layer 13 via

14-hole copper 20 adhesive-backed copper foil

21 copper foil layer 22 insulating glue layer

23 protective film 24 copper electroplating layer

25 second circuit layer 30 via

31-hole copper

Detailed Description

The invention discloses a layer increasing process of a back-adhesive copper foil, which can be used for layer increasing operation of a circuit board and solves the problem of laminating and increasing layers of the circuit board by using a plate.

The following describes a process according to one embodiment of the present invention through fig. 1, 2, 5 to 8.

First, as shown in fig. 1, a substrate circuit board 10 is provided, the substrate circuit board 10 has two build-up

layers

11A and 11B, and the build-

up layers

11A and 11B have

first circuit layers

12A and 12B, respectively. In addition, the substrate circuit board 10 has a via hole 13, and a via copper 14 is provided in the via hole 13 to electrically connect the two

first circuit layers

12A and 12B.

Next, as shown in fig. 2 and fig. 3, two original rolled-up back-adhesive copper foils 20 are sequentially attached to the respective build-

up surfaces

11A and 11B by a vacuum lamination leveling machine in a vacuum lamination manner, please further refer to fig. 4, in which the back-adhesive copper foil 20 has a copper foil layer 21 and an insulating adhesive layer 22, the insulating adhesive layer 22 is coated on the copper foil layer 21, and the

first circuit layers

12A and 12B contact the insulating adhesive layer 22 but do not contact the copper foil layer 21. Before the adhesive-backed copper foil 20 is attached, a protective film 23 may be further attached to a surface of the insulating adhesive layer 22 opposite to the copper foil layer 21 to prevent the insulating adhesive layer 22 from being stained or adhered. As shown in fig. 3, the protective film 23 is removed before the adhesive-backed copper foil 20 is attached to the build-up

surfaces

11A, 11B, and after the adhesive-backed copper foil 20 is attached to the build-up

surfaces

11A, 11B, the insulating adhesive layer 22 may be completely cured, including but not limited to, by thermal curing, thereby forming a permanent connection with the build-up

surfaces

11A, 11B.

As shown in fig. 5, in order to electrically connect the circuits of different layers, a via hole 30 may be formed through the two adhesive-backed copper foils 20 and the substrate circuit board 10, and then, as shown in fig. 6, a via hole 31 may be formed in the via hole 30 so that the two copper foil layers 21 are electrically connected to the two

first circuit layers

12A and 12B, respectively. In other possible embodiments, the steps shown in fig. 5 and 6 may be omitted if it is not necessary to electrically connect the circuits of different layers.

As shown in fig. 7, an electroplated copper layer 24 is respectively plated on the two copper foil layers 21, and then as shown in fig. 8, the two copper foil layers 21 and the electroplated copper layer 24 are respectively patterned into two second circuit layers 25, and the circuit patterning method can be realized by selecting the conventional method of attaching a photoresist, exposing, developing, alkaline etching, and removing the photoresist.

In the foregoing embodiment, the substrate circuit board is a double-layer board, but in other possible embodiments, the substrate circuit board may also be a single-layer board or other multi-layer boards, for example, the structure shown in fig. 8 may be used as the substrate circuit board, and the copper foil with adhesive layer added according to the present invention is performed again.

In the foregoing embodiment, the procedure of adding layers to the adhesive-backed copper foil is performed simultaneously on both sides of the double-layer board, but in other possible embodiments, the procedure of adding layers to the adhesive-backed copper foil may be performed separately on only one side of the substrate circuit board.

The above-described embodiments and/or implementations are only for illustrating the preferred embodiments and/or implementations of the present technology, and are not intended to limit the implementations of the present technology in any way, and those skilled in the art can make many modifications or changes without departing from the scope of the technology disclosed in the present disclosure, but should be construed as technology or implementations that are substantially the same as the present technology.

Claims

1. A process for increasing the layer of a copper foil with back adhesive is characterized by comprising the following steps:

(2) attaching an original coiled back-adhesive copper foil to the surface of the build-up layer in a vacuum film pressing mode, wherein the back-adhesive copper foil is provided with a copper foil layer and an insulating adhesive layer, the insulating adhesive layer is coated on the copper foil layer, and the first circuit layer is in contact with the insulating adhesive layer but not in contact with the copper foil layer;

(3) electroplating a copper electroplating layer on the copper foil layer; and

2. The process of claim 1, further comprising, after the step (2):

(5) a via hole penetrating the copper foil is formed on the copper foil, and a via hole is formed in the via hole to electrically connect the copper foil layer and the first circuit layer.

3. The process of claim 2, wherein step (5) is performed before step (3).

4. The process of claim 1, wherein the copper foil further comprises a protective film attached to a surface of the insulating layer opposite to the copper foil layer, wherein the protective film is removed before the copper foil is attached to the build-up surface.

5. The process of claim 1, wherein after the step (2), the insulating adhesive is further cured completely.