JPS6248518A - Manufacture of sheet material for print wiring - Google Patents

Abstract

PURPOSE:To obtain the titled material, suitable for various kind and small amount production and having high quality without any cavity or the like, by injecting resin while keeping a cavity in a mold in vacuum previously. CONSTITUTION:Molds 1a, 1b closed and a cavity 2 in the molds is kept in vacuum condition by evacuating through an evacuating pipe 5, provided on the mold 1b. The resin, brought into molten condition in a cylinder, is injected into the cavity 2 of the mold, which is evacuated, through a gate 7 to impregnate the resin into a base material 3. In this case, the cavity 2 of the mold is evacuated and air does not exist between respective base materials 3 even in case a plurality of base materials 3 is loaded in the cavity 2, therefore, the resin is impregnated into the base materials 3 without receiving any bothering. Further, gas or air bubbles may be removed since the resin, impregnated into the base materials 3, are put in vacuum atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing printed wiring board materials such as unclad boards and metal foil-clad laminates.

[Background technology]

In general, manufacturing printed wiring board materials such as unclad boards and metal foil-clad laminates requires many steps such as resin impregnation of the base material, drying, cutting, layup, and press molding. Quality control is complicated and difficult because there are many management conditions.For this reason,
This method required large-scale equipment and was not suitable for high-mix, low-volume production.

Therefore, as a manufacturing method for printed wiring board materials suitable for high-mix, low-volume production such as prototyping, a method that applies ordinary injection molding has come to be used. In this method, a base material such as glass cloth is placed in the mold cavity, resin is injected into the base material, the base material is impregnated with the resin, and in the case of a thermoplastic resin, it is cooled, and in the case of a thermosetting resin, the base material is impregnated with the resin. is a method to obtain printed wiring board material by heating and solidifying the resin, which requires fewer steps, and
It does not require large-scale equipment.

However, with this method, when the resin is injected, the air in the base material prevents the resin from being sufficiently impregnated, and the unimpregnated portions of the resin remain as cavities after solidification, which has been a problem.

[Purpose of the invention]

This invention was made in view of the above problems, and is suitable for high-mix, low-volume production because it requires fewer steps and does not require large-scale equipment, and is also a high-quality unclad board with no cavities. The purpose of the present invention is to provide a method for producing printed wiring board materials that can be used to produce materials such as laminates, metal foil cladding materials, etc.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides a printed wiring board in which a base material is placed in a mold cavity, a resin is injected into the mold cavity, and the base material is impregnated with the resin and solidified. The gist is a method for manufacturing a printed wiring board material, which is characterized by injecting resin while keeping the inside of a mold cavity in a vacuum in advance.

Hereinafter, one embodiment of the present invention will be explained based on a hail diagram.

First, as shown in FIG. 1, a pair of molds 1a.

A base material 3 is placed in a mold cavity 2 formed by fitting the base materials 1b into each other. The material of the base material 3 is not particularly limited in the present invention, and may be selected from materials normally used for printed wiring board materials, such as glass, cloth made of fibers such as organic materials, nonwoven fabric, and paper, depending on the resin used. You can choose the suitable one. In the figure, three base materials 3 are stacked in the mold cavity 2, but the number of base materials 3 depends on the thickness of the printed wiring board material to be created, the thickness of the mold cavity 2, and other conditions. You can choose the number that suits you.

When the printed wiring board material is a double-sided metal foil-clad laminate, metal foils 4 and 4 are attached to the la and lbO surfaces of the mold forming the mold cavity 2, respectively, as shown in FIG. .

If the printed wiring board material is not a double-sided metal foil clad laminate,
That is, in the case of a single-sided metal foil-clad laminate or an unclad plate, the metal foil may be attached only to one side of the mold, or may not be attached at all. In addition, in the figure,
Although the metal foil 4 is shown in a waveform, this waveform is not intended to represent the shape, but is provided schematically to distinguish the metal foil 4 and the base material 3.

The molds 1a and 1b are closed, and the inside of the mold cavity 2 is brought into a vacuum state by evacuating through the exhaust pipe 5 provided on the mold 1b side. At this time, the degree of vacuum within the mold cavity 2 is set in consideration of the base material, the type of resin, etc.

In the figure, O-
Although the ring 6 is provided to maintain the vacuum inside the mold cavity 2, the molds 1a and 1 are
The vacuum may be maintained only by the clamping pressure of b.

The resin that has become molten in the cylinder is injected from the gate 7 into the vacuum mold cavity 2 to impregnate the base material 3 with the resin. At this time, the base material 3 in the mold cavity 2 is in a deaerated state, and if multiple base materials 3 are placed, air also exists between each base material 3. Therefore, the resin is impregnated into the base material 3 without any hindrance. Furthermore, gases and bubbles are removed from the resin impregnated into the base material 3 by placing it in a vacuum state.

After this, if the resin is a thermoplastic resin, the molds 1a and 1b are cooled with cooling water, etc., and if the resin is a thermosetting resin, the molds 1a and 1b are cooled to be attached or embedded in the mold, etc. By heating the molds la and lb with a heater to solidify the resin, a high-quality printed wiring board material free of cavities, bubbles, etc. can be obtained.

Next, an example of the mold used in the present invention will be explained.

As shown in FIG. 2, this mold maintains the vacuum inside the cavity 2 by means of a vacuum seal using the aforementioned O-ring 6. - Inside the ring 6, a plurality (three in the figure) of inlets 5a of the exhaust pipes 5 connected to the exhaust ports are arranged in a straight line, and on the surface of the mold 1a facing the population 5a... A groove 8 as shown in FIG. 3 is provided so as to surround a core 9 forming the cavity 2. As shown in FIG.

The mold used in this invention does not necessarily have an exhaust mechanism as shown in FIGS.
etc.), and the mold may simply have the exhaust pipe 5 directly connected to the cavity 2. However, if a mold equipped with an evacuation mechanism as shown in FIGS. 2 and 3 is used in the present invention, more efficient evacuation work can be performed.

In this invention, by changing the shape of the mold cavity used therein, it is possible to produce a printed wiring board material having a corresponding shape. For example, if molding is performed with a bottle protruding into the mold cavity, printed wiring board material with through holes can be produced at the same time as molding.

So far, this invention has been explained based on the molds shown in FIGS. 1 to 3, but the molds that can be used in this invention are not limited to these. For example, in order to make the bottle protrude as mentioned above, in order to move this bottle,
The mold can have a three-plate structure. In short, other structures are not limited as long as the resin can be injected while keeping the inside of the mold vacuum.

As described above, the method for manufacturing printed wiring board materials of the present invention involves impregnation, molding, and solidification of resin in the same mold cavity, so it requires fewer steps and requires large-scale equipment. do not need.

In addition, by simply changing the shape of the mold, printed wiring board materials with different shapes can be produced, making it possible to produce a wide variety of products in small quantities. Moreover, in this invention, since the resin is injected while keeping the inside of the mold cavity in a vacuum in advance, there is no air inside or between the base materials that prevents resin impregnation.
It will be possible to produce high-quality printed wiring board materials without cavities.

〔Effect of the invention〕

The method for manufacturing a printed wiring board material of the present invention is configured as described above, and is suitable for high-quality, low-volume production, and the resin is injected after the inside of the mold cavity is evacuated in advance. This makes it possible to produce high-quality printed wiring board materials without cavities or the like.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram illustrating an embodiment of this invention, Fig. 2 is a perspective view of an example of a mold used in this invention, and Fig. 3 is an example of an exhaust mechanism in this mold. It is a top view of hail. 2... Mold cavity 3... Base material agent Patent attorney Takehiko Matsumoto Diagram 2

Claims (3)

[Claims] (1) A method for producing a printed wiring board material in which a base material is placed in a mold cavity, a resin is injected into the mold cavity, and the base material is impregnated with the resin and solidified,
A manufacturing method for printed wiring board materials that is characterized by injecting resin while keeping the inside of the mold cavity in a vacuum. (2) The method for producing a printed wiring board material according to claim 1, wherein a vacuum is maintained in the mold cavity by providing an O-ring at the parting line of the mold. (3) A method for producing a printed wiring board material according to claim 1 or 2, in which metal foil, which will become printed wiring, is also placed in advance on at least one side of the mold cavity.