JPS6169519A - Method of packaging printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for packaging printed wiring boards (hereinafter abbreviated as PWB).

(Prior art) Conventionally, PWB packaging involves inserting the PWB into a bag made of thermoplastic resin film such as polyethylene, and then simply fixing the opening of the bag with sellotape to prevent the product from flying out. The method was common.

However, in such a conventional PWB packaging method, the degree of sealing of the bag is low, so that the PWB inside the package is easily affected by the outside air environment. For this reason, the PWB easily absorbs moisture, and rust occurs on the surface of the PWB using copper or the like, which is particularly easily oxidized, causing soldering defects. Furthermore, soldering deteriorates the blowhole phenomenon (the generation of voids caused by volatile components in the solder), which greatly deteriorates the quality of P''vVB.

(Objective of the Invention) An object of the present invention is to provide a novel packaging method for PWB that solves the above conventional drawbacks.

(Structure of the Invention) According to the present invention, there are a step of inserting a printed wiring board into a thermoplastic resin film folded into upper and lower halves, and a step of inserting the printed wiring board into a thermoplastic resin film which is folded into two halves, and placing the printed wiring board in a vacuum atmosphere so as to surround the printed wiring board inside the film. A method for packaging a printed wiring board is obtained, which includes the step of heat-sealing the opening of the film after removing air from the surface for a certain period of time.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows an embodiment of the PWH packaging method according to the present invention, and explains the packaging process sequence using the vacuum packaging apparatus shown in FIG. 2.

Moreover, FIG. 3 is a process diagram showing the process of packaging a printed wiring board according to the present invention, and FIG. This shows the packaging process. The present invention will be described in detail below in accordance with the packaging process order.

1) The PWBl in the state shown in Fig. 3(A) is transferred to the vacuum container 1 shown in Fig. 2 by a conveyor (not shown) that conveys the PWBl.
After passing through the seal roll 2 on the zero population side, the vacuum level is 600tt.
The sample is transported into a vacuum container 10 maintained at rt Ht or higher.

2) Next, when the PWB1 passes between a pair of upper and lower film layers 3a and 3b connected by stretching a thermoplastic resin film (abbreviated as ridge film) 4 in the vacuum container 10, the film 4 Figure 4 (A), (B),
The top and bottom are covered in the order shown in (C), resulting in the state shown in FIG. 3 (B). As the film 4, for example, polyethylene, polyvinyl chloride, polychloride and vinyl IJ-ten, etc. can be used.

3) Next, the PWBl is transferred to the right by the conveyor, and the transfer position of the PWBl is detected by the photosensor 5 installed between the conveyors in front of the sealer 6 that seals the opening side 4a of the film 4, and the moving direction of the PWBl ( For example, the lowering timing of the sealer 63 for thermocompression bonding the opening side 4a perpendicular to the direction of the arrow in FIGS. 1 and 2 is determined.
The sealer 63 whose temperature is set to 0°C is lowered to the opening side 4a, and the film 4 is thermally fused and cut by thermocompression bonding with the sealing base 6b having a thermocompression groove in FIGS. 4(D) and (E).
) (shape m in Figure 3(D)).

4) Between a pair of ring-shaped seal rings 7a and 7b that are fitted concentrically to a shaft 7 whose temperature is set to 250° C., with opening sides 4b and 4c on both sides of the film 4 parallel to the direction of movement of the PWBI. (state shown in FIG. 3(D)). The distance between the seal rings 7a and 7b (for sealing two sides) is determined depending on the width of the film 4 from the outside of the vacuum container 10 to the shaft 7.
You can set the desired width by moving.

5) Next, the sealed PWB package is passed between a pair of heating rolls 8 which are preset at 50 to 70"C, thereby removing the film of the PWB package and the film in the outer margin part 4. Shrink it as shown in Figure 3 (E).

6) The packaged PWBl is conveyed out of the vacuum container 10 by a conveyor (not shown) via a seal roll 9 on the exit side.

As described above, the present invention has the following effects.

(1) Since the opening of the film is sealed in an X9 atmosphere, there is no need to provide air vent holes in the film that are required when performing heat shrinkage in the atmosphere, and complete airtightness can be maintained. can. Furthermore, since the film is finished using heated rolls in a vacuum, it is possible to prevent the surface from wrinkling or tearing, which tends to occur when the film shrinks and is taken out into the atmosphere.

(11) Since it is no longer affected by moisture in the atmosphere and oxidation of the PWB surface is prevented, soldering defects caused by rust can be eliminated. Furthermore, the soldering process almost completely eliminates the protrusion phenomenon.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a printed wiring board packaging process according to an embodiment of the present invention, and FIG. 2 is a side sectional view showing the structure of a main part of a vacuum packaging apparatus according to an embodiment of the present invention. A side sectional view of the steps up to. Code 1 in the diagram... Printed wiring board (PWB), 2, 9...
... seal roll, 3 ... film roll, 4 ... (thermoplastic resin) film, 5 ...
...Photo sensor, 5a...Sealper, 6
b...Seal stand, 7...Shirt), 7
a', 7b... Seal ring, 8...
Heating roll, 10... Vacuum container. (C><I: ←φ Richa 3 Figure 3 α Observation / J Figure

Claims (1)

[Claims] A step of inserting the printed wiring board into a thermoplastic resin film folded into two halves, and introducing these into a vacuum atmosphere to remove air around the printed wiring board inside the film for a certain period of time. A method for packaging a printed wiring board, comprising the step of heat-sealing the opening of the film.