JPH0157662B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for manufacturing laminated molded products such as printed wiring boards and laminate boards.

(Prior art and its problems) Conventionally, a plurality of plate-shaped laminated materials such as resin-impregnated sheets, resin films or sheets, metal foils or plates are stacked on top of each other, and the stacked laminate is charged into a forming press. A method is known in which the laminates are integrated by heating, pressurizing, and further cooling as necessary to produce a desired laminate molded product. This is a method for manufacturing laminated molded products such as printed wiring boards and laminate boards.

By the way, when manufacturing a laminated molded product using such a method, if air debris (hereinafter simply referred to as air) remains between the laminated materials that make up the laminated molded product, it may be caused by the residual air. This may result in defects such as voids, which may impair the functionality of the laminate molded product. Therefore, in order to eliminate such problems, the press space of the molding press is sealed and the pressure inside the sealed space is reduced prior to molding, thereby removing air from between the laminated materials of the laminate loaded into the molding press. It has been considered to actively degas the air remaining between the laminated materials to reduce as much as possible the air remaining between the laminated materials, but this method of sealing the press space itself of the forming press has inherent problems when the equipment becomes large-scale. Moreover, there was also the problem that it was difficult to apply it to existing molding presses, and it could hardly be said to be desirable.

On the other hand, as a method that does not require large-scale equipment and can be easily applied to existing molding presses, the laminate is housed in a rubber bag, the inside of the rubber bag is vacuum degassed, and then the laminate is laminated. It is conceivable that the object is placed in the rubber bag between the hot plates of the molding press, and the laminate together with the rubber bag is pressed between the hot plates of the molding press.

However, in such a system using a rubber bag, as the degassing operation inside the rubber bag progresses, the pressure difference between the inside and outside of the rubber bag increases, and the rubber bag is compressed by this pressure difference, causing the laminate to deteriorate. There is a problem in that the air is not necessarily evacuated from between the laminated materials because it is compressed and pressed in the stacking direction, and air is trapped between the laminated materials due to the pressing action. There were circumstances in which it could not be expected to be very effective in preventing the occurrence of defects such as voids.

(Means for Solving the Problems) Against this background, the present invention does not require large-scale equipment, can be easily applied to existing forming presses, and can be applied easily between laminated materials. The purpose of this work is to provide a manufacturing method for laminated molded products that can extremely effectively remove air from the air and prevent the occurrence of defects such as voids. However, when forming a laminated molded product as described above, a bag-shaped container made of a heat-resistant flexible material is used, which is equipped with a check valve in the vacuum suction port whose forward direction is from the inner space to the outer space. using a body and a closed container capable of accommodating the container, and storing the container in the closed container with the laminate stored in the container,
By evacuating the inside of the sealed container, the inside of the container is vacuum evacuated at the same time as the inside of the sealed container, and then, the inflow of gas into the container through the vacuum suction port is controlled by the check valve. Under the condition that it was prevented by
The laminate, housed in the container, is placed between hot plates of a forming press and sandwiched between the hot plates, and the laminate is heated by contact with the hot plates. Apply pressure with
Furthermore, cooling is performed as necessary.

(Operations and Effects) According to the method of the present invention, when the inside and outside of the container in which the laminate is housed is vacuum degassed, the spaces inside and outside the container are maintained at approximately the same atmospheric pressure, so that the difference in air pressure between the inside and outside can be avoided. This effectively prevents the container from being compressed, and therefore prevents the laminate from being compressed and pressed in the stacking direction due to the compression of the container due to the pressure difference between the inside and outside of the container. The pressing action effectively prevents air (gas) from being trapped between the laminated materials, and therefore the air is removed from between the laminated materials extremely well. be. Then, in a state where the air between the laminated materials is extremely well removed by the vacuum degassing operation inside the container, the laminate is heated, pressurized, and Since it is cooled and integrated as necessary, defects such as voids in the laminated molded product are extremely well prevented, and therefore the function of the laminated molded product is prevented from occurring due to residual air. Damage caused by defects such as voids is also extremely well prevented.

According to the method of the present invention, such an effect can be obtained without sealing the press space itself of the molding press by simply using a container for storing the laminate and a sealed container for storing the container. Therefore, there is no need for large-scale equipment for its implementation, and it can be easily applied to existing forming presses.

In addition, in the method of the present invention, a check valve is provided at the vacuum suction port of the container, and when the internal pressure becomes higher than the external pressure, the vacuum suction port is automatically opened and the air inside the container is automatically removed. If the external pressure becomes higher than the internal pressure, the vacuum suction port is automatically closed and the flow of gas into the container is automatically stopped, making handling of the container easier. It also has the advantage of being extremely easy to operate, and when heating and pressurizing between hot plates, the degree of vacuum inside the container can be reduced by simply connecting a specified vacuum degassing device to the vacuum suction port. Another advantage is that it can be easily supplemented as needed.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples thereof will be described in detail based on the drawings.

First, in FIG. 1, reference numeral 10 denotes a bag-like container, which is composed of a flat sheet-like bottom member 12 and a bottomed cylindrical top cover member 16. Bottom member 12
and the upper lid member 16 are adapted to be airtightly and removably fitted at fitting seal parts 20 and 21 formed on their respective peripheral edges, and as shown in the figure, these fitting seal parts 20, 21 forms a bag shape in the fitted state, and a predetermined laminate 1 is placed inside.
A laminate storage space (hereinafter simply referred to as storage space) 14 in which the laminate 8 is stored is formed, and the storage space 14 can be maintained under a predetermined vacuum condition with respect to the external space. The sealing between the peripheral edges of the bottom member 12 and the upper lid member 16 can also be performed by adhesive.

Further, the upper lid member 16 of the container 10 is provided with a check valve 22 that functions as a vacuum suction port and opens to the external space. The air in the space 14 is discharged, and when the air pressure in the outside space becomes greater than the air pressure in the accommodation space 14, the accommodation space 14 can be hermetically sealed off from the outside space. The bottom member 12 and the top lid member 16 of such a container 10 are each made of a resin material such as Tetra (trade name; manufactured by DuPont, USA), which has both heat resistance and flexibility, and is made of a resin material such as Tetra (trade name; manufactured by DuPont, USA), which has both heat resistance and flexibility. During processing, the bottom member 12 and the upper lid member 16
When surface pressure is applied to the upper surface of the container 10, the container 10 can be compressively deformed in the stacking direction of the laminate 18.

When forming a laminate 18 using such a container 10, as shown in FIG.
Container 1 containing laminate 18 in housing space 14
0 is housed in a box-shaped sealed container 24. In addition,
This closed container 24 is one that allows easy loading and unloading of the container 10 and whose volume does not change even when air is discharged. Incidentally, here, a bottom plate-like bottom plate 26 is covered with a bottomed cylindrical top cover 28, and the space between them is kept airtight by packing 30.

Next, the air in the sealed container 24 is exhausted through a port 32 formed in the upper lid 28 using a predetermined vacuum degassing means such as a vacuum pump, and
The inside of the closed container 24 is evacuated to a predetermined pressure.
When the inside of the closed container 24 is evacuated, the external pressure of the container 10 becomes higher than the internal pressure, so the inside of the container 10 is also evacuated through the check valve 22 at the same time. If the inside of the container 10 is vacuum degassed in this way, during the vacuum deaeration operation inside the container 10, the air pressure inside and outside the container 10 can be more accurately maintained at approximately the same level. Since the pressure inside the housing space 14 can be maintained slightly higher than the outside pressure, it is possible to effectively prevent the housing body 10 from being compressed and deformed due to the difference in pressure between the inside and the outside. This effectively prevents air from being trapped between the laminated materials, and allows air to be expelled from between the laminated materials very well.

Note that when the vacuum degassing operation in the closed container 24 is completed, air is injected into the closed container 24 in order to take out the container 10 from the closed container 24. When the air pressure inside the sealed container 24 increases due to the injection of air, the air pressure in the external space of the container 10 becomes higher than the air pressure in the storage space 14. It is automatically shut off from the space, and the atmospheric pressure in the accommodation space 14 is automatically maintained at the set pressure. Incidentally, when the target laminate molded product is a printed wiring board such as a double-sided copper-clad printed wiring board or a multilayer printed wiring board, the atmospheric pressure in the accommodation space 14 is usually 5 to 5.
The appropriate pressure will be set in the range of about 150Torr.

Container 10 by vacuum degassing from closed container 24
After completing the vacuum degassing operation inside the sealed container 24, air is injected into the sealed container 24 as described above.
4 is opened, the container 10 is taken out from the closed container 4, and it is directly inserted and placed between the hot plates of a predetermined molding press in a multi-stage press device or the like. Then, the container 10 is compressed by the hot plate to a position where the upper lid member 16 lightly contacts the upper surface of the laminate 18, and in this state, the laminate 18 is heated by the hot plate, and the laminate 18 is heated. Molten resin, for example, when the laminated molded product is a double-sided copper-clad printed wiring board, as shown in FIG. In the case of a printed wiring board, as shown in FIG. 3, the prepreg 36 and the like inserted between the double-sided printed wiring boards 38 and between the double-sided printed wiring boards 38 and the foil 34 are plasticized and fluidized. . Then, under the heating, a required surface pressure is applied between the hot plates to fill every corner with the fluidized resin, and then the filled resin is cooled as necessary,
Let it harden. Thereafter, a leak valve (not shown) installed in parallel with the check valve 22 is opened to allow the accommodation space 14 to be opened.
The internal pressure is returned to atmospheric pressure, the upper lid member 16 is opened, and the molded laminate (laminate molded product) is taken out.

In the laminate 18 shown in FIG. 2, the copper foil 34, the prepreg 36 and the mirror plate 40 are used as the laminate materials, and in the laminate 18 shown in FIG. 36
The double-sided printed wiring board 38 is made of a laminated material. In addition, in Figures 2 and 3,
42 and 44 are a cushion plate and a jig plate, respectively, and 46 is a guide pin for preventing displacement of each laminated material.

In the laminate molded product manufactured according to such a method, the air between the laminated materials constituting the laminate 18 is effectively removed by a vacuum degassing operation prior to heating with a hot plate and pressurizing operation. , in that state, laminate 1
8 is integrated by heating and pressurizing, it is extremely possible to avoid defects such as voids caused by air remaining between the laminated materials, and therefore, it is possible to avoid defects such as voids due to laminated molding. Damage to the functionality of the product is also extremely well prevented. According to the method of this embodiment, the printing space itself of the molding press is not sealed, and the container 10 is simply
Since such an effect can be obtained simply by using the airtight container 24, the equipment does not need to be large-scale, and it can be applied as is to an existing molding press.

Next, a method that can obtain effects similar to those of the present invention will be explained based on FIGS. 4 and 5. That is, the container 50 shown in those figures is different from the container 10 of the embodiment described above.
It is made of a non-flexible material, for example metal, and has a structure in which a bottomed cylindrical bottom lid 52 and a bottomed cylindrical top lid 4 are fitted so as to be slidable in the vertical direction. There is. The upper lid 54 is provided with a check valve 56 similar to the method of the embodiment of the present invention in which a leak valve is arranged in parallel, and a predetermined vacuum degassing means is used to
Through the check valve 56, the air in the accommodation space 14 can be evacuated. Further, a heat-resistant sealing material 58 made of fluorine rubber or the like is provided on the sliding surface between the upper lid 54 and the lower lid 52.
Thereby, the housing space 14 is hermetically sealed off from the outside space. Note that it is also possible to apply a heat-resistant paste to the sliding surface between the upper lid 54 and the lower lid 52 to keep the space between them airtight.

When pressing the laminate 18 using such a container 50, after storing the laminate 18 in the storage space 14, there is a gap between the upper lid 54 of the container 50 and the top surface of the laminate 8. As shown in FIG. 4, the relative positions of the upper cover 54 and the lower cover 52 are fixed so that a predetermined gap exists between them, and the air inside the container 50 is discharged while the relative positions are fixed. Then, the air pressure inside the container 50 is reduced to a desired pressure. In this way, the air between the laminated materials constituting the laminate 18 can be effectively discharged, similar to the method of the embodiment of the present invention. In addition,
Here, as shown in FIG.
2 is fixed on a predetermined base 60, while a bolt 62 is screwed into the base 60 on which the upper cover 54 is attached.
The lower lid 52 is prevented from descending by
and the upper lid 54 are relatively fixed.

After the air inside the container 50 is discharged in this way and the atmospheric pressure inside the container 50 is set to a desired level, the container 50 is removed from the base 60 and the container 50 is placed on the carrier plate 66. It is placed between the hot plates of a predetermined molding press, and subjected to heating, pressurization, and necessary cooling operations in the same manner as in the embodiment according to the present invention. Even in this case, it is possible to obtain the same effect as the method of the embodiment according to the present invention. Note that the laminate molded product (laminate 18) can be removed from the container 50 by opening the leak valve arranged in parallel with the check valve 56, in the same manner as in the embodiment method according to the present invention.
This will be done after returning the internal pressure to atmospheric pressure.

Although the embodiments of the present invention have been described in detail above, the present invention should not be construed as being limited to such specifics.

For example, in the embodiment described above, during vacuum degassing before the container 10 is inserted between hot plates, the inside of the container 10 is set to an appropriate degree of vacuum (atmospheric pressure) according to the laminated molded product. However, during such vacuum degassing, the degree of vacuum inside the container 10 is roughly set, and the check valve 22 The inside of the container 10 may be adjusted to an optimum degree of vacuum by connecting a vacuum degassing means to further evacuate the inside of the container 10. Further, such supplementation of the degree of vacuum is also effective in cases where a large amount of gas is generated due to fluidization of the resin. In addition, in such a case, it is possible to use a vacuum degassing device installed in the press device as the vacuum degassing means.

Although specific examples will not be listed one by one, it goes without saying that the present invention can be implemented with various modifications and improvements within the scope of the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view for explaining one embodiment of the method of the present invention, and FIGS. 2 and 3 are
FIG. 3 is a cross-sectional view showing an example of a laminate that is integrated according to the method of the present invention. Figures 4 and 5
The figures are explanatory cross-sectional views for explaining different steps of a method for manufacturing a laminate molded product that can achieve the same effects as the method of the present invention. 10: container, 12: bottom member, 14: laminate storage space, 16: upper lid member, 18: laminate, 20,
21: Fitting seal portion, 22: Check valve, 24: Airtight container, 30: Packing.

Claims (1)

[Claims] 1. A plurality of plate-shaped laminated materials such as resin-impregnated sheets, resin films or sheets, metal foils or plates are stacked on top of each other, and the stacked laminate is charged into a molding press, heated, A check valve whose forward direction is from the inner space to the outer space when manufacturing the desired laminate molded product by integrating the laminates by pressurizing and further cooling as necessary. A bag-shaped container made of a heat-resistant flexible material, which is equipped with a vacuum suction port, and a sealed container that can accommodate the container are used, and the laminate is housed in the container. The container is housed in the airtight container, and the inside of the container is vacuum degassed, so that the inside of the container is vacuum degassed at the same time as the airtight space, and then the air inside the container is removed through the vacuum suction port. The laminate is placed between the hot plates of the molding press while being housed in the container, and sandwiched between the hot plates, with the check valve preventing gas from flowing into the housing. A method for manufacturing a laminate molded product, characterized in that the laminate is heated by contact with hot plates, the pressurization is applied with the hot plates under the heating, and the cooling is further performed as necessary. 2 heating the laminate between hot plates of the forming press;
When pressurizing and cooling, a predetermined vacuum degassing device is connected to the vacuum suction port of the container, so that the degree of vacuum inside the container can be supplemented and the degree of vacuum can be adjusted to the optimum degree. A manufacturing method according to claim 1, characterized in that: