KR101799179B1

KR101799179B1 - Rigid flexible circuit board manufacturing method

Info

Publication number: KR101799179B1
Application number: KR1020160007126A
Authority: KR
Inventors: 박정기; 박병규; 정경길
Original assignee: 주식회사 코리아써키트
Priority date: 2016-01-20
Filing date: 2016-01-20
Publication date: 2017-11-17
Also published as: KR20170087305A

Abstract

A method of manufacturing a rigid flexible circuit board according to the present invention includes the steps of: a) providing an inner layer circuit board having an inner layer circuit pattern formed on its surface; b) laminating an insulating layer on the innerlayer circuit board; c) Forming an outer layer circuit pattern in the rigid region in the surface; d) primary processing the stepped portion, which is a boundary between the rigid region and the flexible region in the insulating layer, with a drill bit when the outer layer circuit pattern is formed; and e) A step of secondarily processing a stepped portion of the insulating layer which is a boundary between the rigid region and the flexible region after completion of the processing; f) a step of removing a part of the insulating layer located in the flexible region of the insulating layer The step of completing the rigid flexible circuit board can be used to deeply process the high multilayer circuit board which has not been processed with a conventional method, Can be prevented from being damaged, and subjected to deep processing step of cracking and high multi-layer circuit board of the step processing site also provides a substrate manufacturing method which improves the step-rigid flexible circuit processing unit uniform properties.

Description

Technical Field [0001] The present invention relates to a rigid flexible circuit board manufacturing method,

The present invention relates to a method of manufacturing a rigid flexible circuit board, and more particularly, to a method of manufacturing a rigid flexible circuit board by processing a step of a boundary between a rigid area and a flexible area of a rigid flexible circuit board in one or two circuits, A rigid flexible circuit substrate manufacturing method capable of deep stepping processing, preventing damage to a flexible area, and improving process uniformity of a stepped portion even when cracking of a stepped portion and deep stepping of a multi-layered circuit board is performed .

In recent years, the degree of integration of semiconductor elements has become higher and higher, and the number of connection pads disposed in semiconductor devices for connecting semiconductor devices to external circuits is increasing and the density of excretion is also increasing.

For example, when the minimum processing dimension of a semiconductor element made of silicon or the like is about 0.2 탆, it is necessary to dispose about 1000 connection terminals in a semiconductor element of about 10 mm.

In addition, in a semiconductor device such as a semiconductor package on which such a semiconductor device is mounted, miniaturization and thinning are demanded in order to improve the mounting density and the like. Particularly, portable devices such as a notebook PC (personal computer) In order to cope with information devices and the like, miniaturization and thinning of semiconductor packages are major problems.

In order to package a semiconductor element, it is necessary to mount the semiconductor element on a wiring board and to connect the connection terminal of the semiconductor element and the connection terminal on the wiring board.

However, when about 1000 connection terminals are arranged around a semiconductor device of about 10 mm, the pitch of the semiconductor device is very small, about 40 탆. In order to connect the connection terminal provided at such a fine pitch to the connection terminal provided on the wiring board, very high precision is required for forming the wiring on the wiring board and positioning the wiring on the wiring board. There is a problem that it is very difficult to cope with TAB (Tape Automated Bonding) technology.

In recent years, various multilayer printed circuit boards capable of mounting them on the surface have been developed in accordance with miniaturization and integration of electronic components. Particularly, the space occupied by the printed circuit board can be minimized, and three- Active research is being conducted on a rigid printed circuit board.

Such a rigid printed circuit board includes a rigid domain having an insulating layer and a mechanical strength and an elastic flexible region connecting the rigid regions to each other, It is mainly used in small terminals such as mobile phones which require high integration by eliminating unnecessary space due to the use of a connector in response to demands for high integration and fine pitch of components.

Registration No. 10-1009072 (Jan. 11, 2011), which is published in the Korean Intellectual Property Office (KIPO), proposes an invention relating to a method of manufacturing a rigid printed circuit board capable of minimizing damage to a display caused during window processing.

However, in the above-described technique, a base substrate (flexible film) partitioned into a rigid region and a flexible region is provided, a plurality of circuit layers are laminated on the base substrate, and then a flexible region F of the printed circuit board is removed to finally complete the rigid printed circuit board. In this case, there is a fear that the base substrate is damaged by the laser beam when the circuit layer of the flexible area F is removed.

In general, in order to improve the adhesion between the circuit layers in the case of stacking a plurality of circuit layers, oxidation treatment is performed on the surface of the circuit layer, that is, the surface of the metal layer on which the circuit pattern is formed, wherein the metal layer is discolored by the oxidation treatment liquid, The laser light used for removing the circuit layer in the flexible area F is absorbed.

In other words, the oxidized metal layer improves the bonding strength but fails to function as a stopper in the laser process due to the discoloration due to the oxidation process. As a result, laser light is emitted to the base substrate in the process of removing the circuit layer in the flexible area (F) And the base substrate is damaged.

As described above, according to the conventional technology, when the stepped portion, which is the boundary between the rigid region and the flexible region of the high-multilayered circuit board, is machined only with the metal footstitch, cracks are generated in the stepped portion due to the punching impact, There is a problem that the drilling depth of the drill bit is difficult to control, and the substrate in the flexible area is damaged by the drilling.

The present invention proposes a method for manufacturing a rigid multi-layered circuit board which can process deep multi-level circuit boards which can not be machined by strokes by machining one or two steps between the rigid and flexible regions of the rigid flexible circuit board, And it is an object of the present invention to provide a method of manufacturing a rigid flexible circuit substrate in which cracking of a stepped portion and deep step processing of a high multilayer circuit board are performed to improve process uniformity of the stepped portion.

A method of manufacturing a rigid flexible circuit board according to the present invention includes the steps of: a) providing an inner layer circuit board having an inner layer circuit pattern formed on its surface; b) laminating an insulating layer on the innerlayer circuit board; c) A step of forming an outer layer circuit pattern on a surface of the inner layer circuit board in a region between the rigid region and the flexible region of the insulating layer when the outer layer circuit pattern is formed; Of the insulating layer having a remaining thickness of 150 to 450 탆 which is a boundary between the rigid region and the flexible region in the insulating layer is subjected to a second machining And f) completing the secondary processing of the stepped portion, removing the insulating layer located in the flexible region of the insulating layer to complete the rigid flexible circuit board Eojinda.

At this time, in the step of providing the inner layer circuit board, which is the step a) according to the present invention, it is preferable that the insulating film is laminated on the flexible region of the innerlayer circuit board.

In the step of laminating the insulating layer on the inner layer circuit board according to the step b) of the present invention, it is preferable that the release film is laminated on the insulating film laminated on the flexible region of the innerlayer circuit board.

delete

The method of manufacturing a rigid flexible circuit board according to the present invention has the following effects.

First, there is an effect that deep steps of a high-multilayered circuit board which can not be machined with a punch can be processed by machining the steps of the rigid flexible circuit board between the rigid region and the flexible region in one or two steps.

Secondly, it is possible to prevent damage to the flexible region, and it is possible to improve the process uniformity of the stepped portion even when cracking of the stepped portion and deep stepping of the multi-layer circuit board is performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating a process for manufacturing a rigid flexible circuit board according to an embodiment of the present invention; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately The present invention should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, at the time of the present application, It should be understood that variations can be made.

The present invention proposes a method for manufacturing a rigid multi-layered circuit board which can process deep multi-level circuit boards which can not be machined by strokes by machining one or two steps between the rigid and flexible regions of the rigid flexible circuit board, The present invention relates to a method of manufacturing a rigid flexible circuit substrate in which cracking of a stepped portion and deep stepping of a high-multilayered circuit board are performed to improve process uniformity of the stepped portion.

First, referring to FIG. 1, an inner layer circuit board 10 is provided in a).

The inner layer circuit board 10 provided in the step a) is provided with a base layer 11 as an insulating material and a flexible circuit board on which an inner layer circuit pattern 12 is formed on the basis of the base layer 11 .

At this time, the inner layer circuit board 10 may be provided as a one-sided circuit board on which the inner layer circuit pattern 12 is formed on either the upper or lower surface with respect to the base layer 11, And the inner layer circuit patterns 12 formed on the upper and lower surfaces of the double-sided circuit board may be provided as vias on the upper and lower surfaces of the base layer 11, .

An insulating film 13 is laminated on the flexible region of the inner layer circuit board 10, and the insulating film 13 forms the surface of the flexible region.

Therefore, it is preferable that the insulating film 13 is provided as a cover-ray or PSR (Photo Solder Resist) film which can be insulated to protect the circuit in the flexible area.

Next, in step b), the insulating layer 20 is laminated on the surface of the innerlayer circuit board 10 provided by the step a).

At this time, the insulating layer 20 according to an embodiment of the present invention is formed by bonding a copper foil 21 as a conductive layer to the surface of the insulating layer 20, and the copper foil 30 is patterned to form an outer layer circuit pattern.

Here, the insulating layer 20 according to an embodiment of the present invention is preferably laminated with a prepreg in which the copper foil 21 is bonded to the upper surface of the insulating layer 20 so as to maintain the physical properties of the rigid region .

The insulating layer 20 bonded to the inner layer circuit board 10 is bonded by a press method in which the press is preferably performed by a hot press applying heat and pressure at a preset temperature.

The release film 22 is laminated on the insulation film 13 laminated on the flexible region of the innerlayer circuit board 10 before the insulation layer 20 is laminated on the innerlayer circuit board 10, The release film 22 is provided for facilitating the peeling of the insulating layer 20 located in the flexible region at the time of later stepwise processing.

Next, in step c), the outer layer circuit pattern 23 is formed in the rigid region of the surface of the insulating layer 20. [

At this time, the outer layer circuit pattern uses the copper foil 21 bonded to the surface of the insulating layer 20. It is also possible to perform electroless copper plating for uniform roughness on the surface of the copper foil 21, The copper plating may be omitted depending on the surface condition of the copper foil.

Then, a dry film is laminated on the surface of the copper foil 21 on which the electroless copper plating is performed, and then a mask constituting a pattern corresponding to the outer layer circuit pattern is laminated. Then, ultraviolet (UV) To perform a photolithography process of reacting a dry film, which is a monomer, with a polymer to reproduce a necessary pattern image.

Then, in the exposure operation, a portion which is not changed into a polymer is removed by using sodium carbonate to form an image pattern of a pattern corresponding to the outer layer circuit pattern 23.

When the portion excluding the image pattern portion of the dry film is removed through the developing operation, electroplating is performed on the exposed portion of the copper foil 21 except the portion where the image pattern is formed.

Then, the dry film is peeled off from the copper foil 21, and then the copper foil 21, which is not subjected to electrolytic copper plating, is removed by etching to provide insulation between the conductive patterns.

In the above etching process, it is preferable that after the mask is laminated on the outer layer circuit pattern 23 as in the normal etching operation, only the copper foil of the portion where the mask is not laminated is etched.

The outer layer circuit pattern 23 is formed on the insulating layer 20 by the above process.

It is preferable that the outer layer circuit pattern 23 is not formed in the flexible region of the insulating layer 20 and the solder resist 24 is applied on the outer layer circuit pattern 23 to protect the outer layer circuit pattern 23 do.

Next, in step d), a stepped portion, which is a rigid region and a flexible region boundary, in the insulating layer 20 is first processed.

At this time, the processing of the stepped portion is performed by drilling, and drilling is performed so that only a part of the insulating layer having a thickness of 150 to 450 μm is left with respect to the surface of the inner layer circuit board.

The drilling performed here is NC drilling using a drill bit, and the reason why only the insulating layer is left with a thickness of 150 to 450 탆 is the permissible working thickness of the metal stamping or laser processing to be performed at a later time.

By the above-described process, it is possible to deeply process the stepped portion, which is the boundary between the rigid region and the flexible region.

Next, in step e), the stepped portion, which is the boundary between the rigid region and the flexible region, of the insulating layer 20, which is primarily processed by the step d), is processed.

The stepped portion is processed by a metal mold or a laser drilling. The metal mold is pressed on the insulating film 13 of the flexible region by a pair of cuts located at a step portion, which is a border between the rigid region and the flexible region, The insulating layer 20 is machined to the release film 22.

In the laser drilling, the stepped portion is processed by laser drilling along the step portion which is the boundary between the rigid region and the flexible region to the release film 22 laminated on the insulating film 13 in the flexible region.

By the above-described process, the stepped portion processing, that is, the rigid region and the flexible region boundary, is completed.

Next, in the step f), the rigid flexible circuit board is completed by removing a part of the insulating layer located in the flexible region by the secondary processing.

Therefore, in the above-described process according to the embodiment of the present invention, the steps of the border between the rigid region and the flexible region of the rigid flexible circuit board are processed in one or two steps, and deep step processing of a high- In addition, damage to the flexible region can be prevented, and even when cracks in the stepped portion and deep stepping of the high-multilayered circuit board are performed, the process uniformity of the stepped portion is improved.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: Inner layer circuit board
11: base layer
12: Inner layer circuit pattern
13: Insulation film
20: Insulation layer
21: Copper foil
22: release film
23: outer layer circuit pattern
24: Solder resist

Claims

a) providing an inner layer circuit board having an inner layer circuit pattern formed on its surface;
b) laminating an insulating layer on the innerlayer circuit board;
c) forming an outer layer circuit pattern on the surface of the insulating layer in the rigid region;
d) primary processing the stepped portion, which is a boundary between the rigid region and the flexible region in the insulating layer, with a drill bit so that only a part of the insulating layer having a thickness of 150 to 450 탆 remains on the basis of the surface of the inner layer circuit substrate;
e) secondary processing the part of the insulating layer having the remaining thickness of 150 to 450 탆, which is the boundary between the rigid region and the flexible region in the insulating layer, after completion of the primary processing, with a metal tapping; And
f) completing the secondary processing of the stepped portion, removing the insulating layer located in the flexible region of the insulating layer to complete the rigid flexible circuit board.

The method according to claim 1,
In the step (a) of providing the inner-layer circuit board,
Wherein an insulating film is laminated on the flexible region of the inner-layer circuit board.

The method of claim 2,
In the step of laminating the insulating layer on the inner layer circuit board, which is the step b)
Wherein the release film is laminated on the insulating film laminated in the flexible region of the inner-layer circuit board.

delete