JP2003046218A - Method of laminating copper foil upon printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a flat and uniform insulating layer on a printed circuit board in a controllable state. SOLUTION: In a method of laminating copper foil upon printed circuit board, copper foil 504 is laminated upon the upper and lower surfaces 501 and 502 of the substrate 500 of the printed circuit board. In order to form insulating layers 503 on the substrate 500, both surfaces of the substrate 500 are coated with an insulating material 503. The insulating layers 503 can be formed by roll coating, spray coating, or screen printing. The thicknesses of the layers 503 can be controlled in accordance with the demand from a circuit. Various types of metal foil 504 can be fixed on the substrate 500 by laminating the foil 504 upon an adhesive layer and performing a heating step and a compressing step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board. More particularly, the present invention relates to a method of laminating a metal foil on a printed circuit board.

[0002]

BACKGROUND OF THE INVENTION The increasing complexity of electronic products requires increasing density of printed circuit boards (PCBs) that can be manufactured in two different ways. This PCB can be manufactured by a lamination method or an assembly method. Multilayer circuit boards are an example of high density printed circuit boards. In this multilayer circuit board, a plurality of patterned trace layers are laminated together. Therefore, the circuits of each patterned trace layer are connected to each other. A laminated printed circuit board such as a multi-layer circuit includes a plurality of prepregs provided between layers and fixed to each other.

1a and 1b show two types of coated copper foil. FIG. 1a shows one layer of copper foil 101 covered with an insulating layer 100 such as prepreg. On the other hand, FIG. 1b shows a layer of insulating metal 100 laminated between two layers of copper foil 101, 102 such as prepreg. These coated copper foils 101, 102 are typically used as cores or raw materials for PCBs to withstand additional circuit features. Due to the great complexity of PCB design, different sizes of raw materials and different types are required to meet the demand. Unfortunately, conventional coated copper foil 1
01, 102 is limited to a particular size due to the fact that the thickness of the insulating layer 100 is limited by the type of copper foil used.

[0004]

However, the thickness of the insulating layer of the PCB can affect the radio frequency (RF) characteristics and the impedance of the circuit. Therefore, the PCB thickness is controlled by the requirements of the circuit characteristics. Conventional methods of producing coated copper foils are limited to a certain size, and the RF characteristics of the PCB and the impedance of the PCB cannot be easily controlled. Another drawback of conventional methods is the problem of alignment during the lamination process.

The present invention seeks to overcome the above-mentioned drawbacks of the prior art.

It is an object of the present invention to provide a method for laminating a metal foil on a printed circuit board on which an insulating layer has been formed by rolling.

Another object of the present invention is to provide a method for adhering a metal foil on a printed circuit board on which an insulating layer is formed by a spray method.

Another object of the present invention is to provide a method of adhering a metal foil onto a printed circuit board formed by a screen printing method.

[0009]

To achieve the above object, the present invention provides a step of providing a substrate having an upper surface and a lower surface, and insulating on the upper surface and the lower surface of the substrate. Coating a material, performing a curing step so that the insulating material can form an insulating layer on the upper surface and the lower surface of the substrate, and on the upper surface of the substrate And laminating a metal foil over the insulating layer formed on the lower surface, the method of manufacturing a substrate of a printed circuit board.

The above general description and the following detailed description are merely specific examples and are not intended to limit the present invention.

The accompanying drawings include a further understanding of the invention and are incorporated into and constitute a part of this specification. The illustrated form of the invention together with the description of the drawings serves to explain the nature of the invention.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method of laminating copper foil on a printed circuit board. Various types of coating methods will be described in the following embodiments. See FIG. The insulating material is applied on the substrate by the rolling method according to the first preferred embodiment of the present invention. The substrate 200 has an upper surface 201 and a lower surface 202. Circuitry (not shown) can be formed on the surface of the substrate. The substrate 200 is a flame-retardant epoxy-glass fabric composite resin.
site resin) (FR-4, FR-5) or bismaleimide-
It is made of a material such as triazine (bismaleimide-triazine; BT). The insulating layer 203 can be formed in such a manner that the insulating layer is directly coated on the substrate by a suitable coating means such as roll coating. The insulating material 203 may be coated only on the upper surface 201 of the substrate, only on the lower surface 202, or on both the upper and lower surfaces. The insulating material 203 is a liquid epoxy resin.
n), polymers, polyimides and the like. In the rolling process, at least two rollers 204,2
Use 05. First, an insulating material 203 is coated on the outer peripheral surfaces of these rollers, and then these rollers 2
04 and 205 are laminated on both surfaces of the substrate. These rollers 204, 205 can be rolled backwards and forwards to ensure that the insulating material 203 is evenly and reliably coated on both surfaces of the substrate. When the insulating material 203 is coated on both surfaces of the substrate, the insulating material 20
A curing step is performed so that 3 is cured.

FIG. 3 shows an insulating material applied on a substrate by a spray method according to a second preferred embodiment of the present invention. The substrate 300 has an upper surface 301 and a lower surface 302. The insulating material 303 may be coated on only the upper surface 301 of the substrate or the lower surface 302.
It may be coated on only one side or on both the upper surface and the lower surface. The spray device includes a plurality of spray nozzles 304. An insulating material 303, such as liquid epoxy, is provided by a nozzle 304 that sprays the liquid epoxy onto both surfaces of the substrate. Nozzle 304
Are configured such that the insulating material 303 is applied flat and precisely on both surfaces of the substrate. The power and spray patterns are automatically controlled and precisely cover both surfaces of the substrate with a flat and uniform insulating layer. When the insulating material 303 is coated on both surfaces of the substrate, the insulating material 30
A curing step is performed so that 3 is cured.

FIG. 4 shows an insulating material applied on a substrate by a screen printing method according to a third preferred embodiment of the present invention. The substrate 400 has an upper surface 401 and a lower surface 402. In this third preferred embodiment, two fixed blocks 405 and blades 40
I am using 4. The insulating material 403 may be coated only on the upper surface 401 of the substrate, only on the lower surface 402, or on both the upper and lower surfaces. An insulating material 403, such as liquid epoxy or polymer, is uniformly coated by blade 404 over the surface of the substrate. Insulation material 40
When 3 is coated on both surfaces of the substrate, a curing step is performed so that the insulating material 403 is cured.

FIG. 5 is a schematic sectional view of a metal foil laminated on a substrate 500. The substrate 500 has an upper surface 501 and a lower surface 502, and an insulating layer 503 is formed on the upper surface 501 and the lower surface 502. Once the insulating material 503 is coated over the surface of the substrate 500, circuits (not shown) can be patterned on the substrate 500. Insulating material 503 is filled within the bias of the circuit (not shown), thereby eliminating the electrical filling step of the bias. The curing process is performed to cure the insulating material 503 on the substrate. Insulating layers 503 are formed on both surfaces of the substrate. Next, a metal foil 504 is laminated on these insulating layers 503. A heating step and a compression step are performed that bond the metal foil 504 onto the insulating layer 503. Metal foil 5
Examples of 04 include copper foil.

The above-described embodiment is used as a specific example, and thus the method of coating the insulating material of the present invention is not limited to that of the above-described embodiment. The insulating material is coated directly on the surface of the substrate. The thickness of the insulating layer is controlled by the parameters of equipment such as rolling equipment, spray equipment, screen printing equipment and the like. The metal foil is laminated on the insulating layer formed on the upper surface and the lower surface of the substrate. Since the thickness of the insulating layer can be easily controlled by the parameters of the equipment, various metals such as high copper foil, low copper foil, reverse copper foil, etc. Can be used. The thickness of the insulating layer and the thickness of the metal foil used can be varied according to the requirements of the circuit.

The advantages of the present invention are as follows. 1. The thickness of the insulating layer can be easily changed according to the needs of the circuit configuration on the substrate. In fact, printed circuit board thickness can affect radio frequency (RF) characteristics and circuit impedance. In the traditional way,
The thickness of the printed circuit board is limited by the type of metal foil used to coat it. Thus, it is very difficult to make the printed circuit board thin or thick. On the other hand, since the insulating material of the present invention is directly coated on the surface of the substrate, the thickness of the insulating layer can be changed and the thickness can be controlled. This makes it possible to easily form a flat and uniform insulating layer. 2. The increasing demand for high density integrated circuits is to reduce the size of PCBs and improve reliability. Since the thickness of the insulating layer located on the substrate of the present invention can be easily controlled, the thickness of the PCB can be reduced by reducing the thickness of the insulating layer. This can reduce impedance and improve RF signal transmission. 3. The insulating material used has good adhesive properties and is inexpensive. Therefore, the present invention is suitable for use in mass production. 4. Since the insulating material is used to fill the bias,
No additional electrical filling step is required. Therefore,
The manufacturing process is simplified. 5. Since all processes are performed in one line,
The integration of all products can be improved.

Other embodiments of the present invention will be apparent to those skilled in the art from the description of the present application and the contents of the embodiments described above. The detailed description and embodiments set forth in the invention are merely specific examples, and the true scope and spirit of the invention are set forth in the following claims.

[Brief description of drawings]

1a is a schematic cross-sectional view of a coated copper foil. FIG.

FIG. 1b is a schematic cross-sectional view of a coated copper foil.

FIG. 2 is a schematic diagram showing the first embodiment of the present invention, showing a state in which an insulating material is coated on a substrate by rolling.

FIG. 3 is a schematic view showing a second embodiment of the present invention, showing a state in which an insulating material is coated on a substrate by spraying.

FIG. 4 is a schematic view showing a third embodiment of the present invention, showing a state in which an insulating material is coated on a substrate by screen printing.

FIG. 5 is a schematic sectional view showing a state in which a metal foil is laminated on a substrate coated with an insulating material.

[Explanation of symbols]

200 substrates 201 upper surface 202 lower surface 203 insulating material 204 Laura 205 Laura 300 substrates 301 upper surface 302 lower surface 303 insulating material 304 nozzle 400 substrates 401 upper surface 402 lower surface 403 Insulation material 404 blade 405 fixed block 500 substrates 501 upper surface 502 lower surface 503 insulation layer 504 metal foil

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Lee Shousu             86th street, 2nd play, 5th play, 1st tier, Lake Jiangning Road, Taipei City, Taiwan

Claims (3)

[Claims] 1. A method of laminating copper foil on a substrate of a printed circuit board, the method comprising: providing a substrate having an upper surface and a lower surface; and on the upper and lower surfaces of the substrate. Coating an insulating material thereon, performing a curing step so that the insulating material can form an insulating layer on the upper surface and the lower surface of the substrate, and the substrate of the Laminating a metal foil on an insulating layer formed on the upper surface and the lower surface, the method comprising: laminating a copper foil on a substrate of a printed circuit board. 2. The method according to claim 1, wherein the substrate is a flame-retardant epoxy-glass cloth composite resin (FR).
-4, FR-5) or bismaleimide-triazine (BT)
A method characterized by being made from. 3. A method of laminating a copper foil on a substrate of a printed circuit board, the method comprising: providing a substrate having an upper surface and a lower surface, the upper surface and the lower surface of the substrate. Coating an insulating material thereon, performing a curing step so that the insulating material can form an insulating layer on the upper surface and the lower surface of the substrate, and the substrate of the Laminating a metal foil on the upper surface and the lower surface, and performing a heating step and a compression stroke to fix the metal foil to the surface of the substrate. A method of laminating a copper foil on a substrate of a printed circuit board.