KR20020042372A - The Reduction Method of gas and air in F.P.C. - Google Patents

Abstract

PURPOSE: A method for removing air bubbles from an FPC is provided to remove moisture and the air bubbles in an FPC fabrication process by performing a dry process using an incubation bath. CONSTITUTION: A surface film(1) is used for protecting a copper foil(3). The surface film(1) and the copper foil(3) are adhered to each other by an adhesive(2). A plurality of components are adhered on the copper foil(3) by a soldering process. A base film(5) is used for protecting the copper foil(3). The copper foil(3) and the base film(5) are adhered to each other by an adhesive(4). A reinforcement plate(7) is used for adhering easily an FPC to electronic components. The base film(5) and the reinforcement plate(7) are adhered to each other by an adhesive(6). A release paper(8) is formed by a paper. Moisture and gases are removed from the FPC by performing a heating process and a dry process using an incubation bath. The dry process is performed by using heat dispersion. The moisture and the gases are removed by performing the dry process under a predetermined temperature during one hour.

Description

Bubble Reduction in FPC {The Reduction Method of gas and air in F.P.C.}

The present invention is to prevent from entering the mass production system due to many problems in the production of bubbles due to moisture between the GAS and the adhesive of EPOXY resin.

Currently, the use of FPC in Japan and Korea is essential for electronic products as well as CD-ROMs, and the companies that manufacture FPC have made a lot of research and are trying to supply parts without defects. However, the actual production of parts by mounting the FPC is too difficult and much more profitable than the actual situation even in Japan to avoid the production. This is because of the difficulty of making products without defects and the mass production system cannot be established.

In the conventional process, the first step of printing the solder on the FPC for soldering, the second step of mounting the parts on the FPC printed by the automatic machine, and the automatic soldering process on the mounted parts and the FPC by soldering The third step is the fourth step of separating the aggregated FPC with the mold separately into the mold.In this process, the automatic soldering of the third step is included in the FPC manufacturing process. And there is a problem that a large amount of bubble failure occurs.

The present invention removes fine water and bubbles that are contained inherently in the manufacturing process of the FPC because it does not satisfy the function as an electronic component requiring precision because a large amount of defects caused by bubbles as described above. Therefore, it will be to solve the defect caused by this, establish a mass production system, make high quality electronic parts in mass production, and satisfy customer's desire.

The present invention to achieve the object for this purpose is a conventional four-step manufacturing process is different depending on the material of the FPC, but added in the manufacturing process of the FPC by adding a step of drying for about 2 hours at 120 ℃ in a vacuum-sealed thermostat It is characterized by removing the fine water and bubbles.

1 is a cross-sectional view of a typical FPC

Figure 2 (A) is a top view of the general set FPC

Figure 2 (B) is a bottom view of the general set FPC

3 (A) shows a state after the parts are mounted on the FPC and subjected to an automatic soldering process.

3 (B) is a bottom view after mounting a component on an FPC and undergoing an automatic soldering process

4 (A) is a state in which moisture and bubbles generated in the FPC

Figure 4 (B) is an enlarged photograph of the site where the moisture and bubbles generated in the FPC

5 (A, B) is a state in which moisture and bubbles are removed from the FPC

6 is a method of drying the FPC

《FPC mounting process》

Step 1: remove moisture and gas inside the FPC

Second Process: SOLDER Printing for Soldering

3rd step: mounting parts by automatic equipment

4th step: Automatic soldering by soldering device

5th process: individual separation of mold FPC

Code explanation of main parts of drawing

1. Surface film 2. Adhesive

3. copper foil 4. glue

5. Base film 6. Adhesive

7. Reinforcement plate 8. Release paper

Referring to the process by the accompanying drawings as follows.

It must go through a very difficult process to fabricate the FPC as shown in Figure 1 is a side view of the FPC detailed drawing cut.

1 is a cross-sectional view of an FPC surface film for protecting a copper foil (1) base film to protect the copper foil (3) adhesive (4) copper foil to attach the parts by soldering the surface film and the adhesive (2) for bonding the copper foil Film (5) Adhesive (6) Reinforcement plate (7) for easy attachment of FPC to electronic devices Consists of release paper (8) made of paper, etc. In the process of joining the plate, this material, such as GAS, moisture, etc. is contained, which can not be confirmed by the naked eye in general, and has to be judged only after the production.

First of all, the defect rate that occurs in the process only 50%, the situation is to repair or abandon. In addition, the external credibility of quality also has a bad image. The production itself with these problems is not only the loss of the company but also the national loss. Therefore, in order to solve this problem, the hole was first made in the reinforcing plate, so that the GAS or the fine moisture escaped through the hole, but some problems were solved, but the complete problem was not solved. In order to solve this problem, I tried to dry it in a regular thermostat because it could not remove moisture and gas before putting it into production. However, FPC itself makes secondary production of surface film and shrinkage of base film, which makes production more difficult. Secondhand was inevitable. Therefore, the drying method alone does not solve the problem, and as shown in FIG. 6, a method of removing moisture and GAS in a short time using a vacuum at a lower temperature (80 ° C. to 85 ° C.) by supplementing a thermostat to a high temperature and a long time is performed The problem was solved by adoption.

As can be seen from the above, the present invention devised and invented an additional manufacturing process for the fine bubbles and impurities that are originally contained in the manufacturing process of the FPC, thereby reducing the process defect of the FPC to 1.5% and enabling mass production. Reduction of production cost and externally, stable quality and high reliability can increase sales.

Claims (1)

In manufacturing electronic components by mounting components on FPC Heating and drying using a thermostat to remove moisture and bubbles in a conventional process of mounting a component to the FPC to produce a product, Drying step due to diffusion of heat in the natural state by sealing during the heating, drying process Method of removing moisture and GAS by heating at a constant temperature (80 ℃ ~ 85 ℃) for about 1 hour during the drying step.