JPH0677880B2 - Hot press - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a hot press, and more particularly to a hot press suitable for pressurizing and adhering a multilayer printed wiring board of various electronic devices such as a computer.

[Background of the Invention]

In recent years, in order to realize high-density mounting of parts on a molded article such as a printed wiring board, there is a tendency to make a plurality of printed wiring boards multi-layered. In order to realize this multilayer structure, a wiring board material having better properties and a highly accurate hot press for heating and pressing the wiring board material are required.

A hot press for heating and adhering a plurality of printed wiring boards in a multi-layer structure is disclosed in, for example, JP-A-59-87894. As shown in FIG. 3, this hot press includes a lower bolster 1, an upper bolster 2 which is disposed so as to face the lower bolster 1, and which is connected to a press frame 3 through a column 4 and a lower bolster 1. The lower heating plate 5 fixed to the upper surface via a heat insulating material 6 and the upper bolster 2
An upper heating plate 7 fixed to the lower surface of the lower plate via a heat insulating material 8, a ram cylinder 9 mounted on the press frame 3 and moving the lower bolster 1 toward the upper bolster 2, and a ram cylinder 9
And the driving hydraulic device 10 of FIG. The multi-layer printed wiring board 11 is provided between the lower heating plate 5 and the upper heating plate 7.
At the same time that both heating plates 5 and 7 are heated by a heating source (not shown), the lower bolster 1 is moved by the ram cylinder 9 to press and bond the multilayer printed wiring board 11. The bonded printed wiring board 11 is cooled in a pressurized state to complete the bonding process.

By the way, due to the high performance of wiring board materials,
It has been required to reach a high temperature of 400 ° C or higher, and in a hot press capable of heating to such a high temperature, an electric heater is used as a heating source. For cooling the hot platen at high temperature, a water cooling system is adopted in which a cooling passage is provided in the hot platen and cooling water is circulated in the cooling passage to cool the hot platen. And when adopting such a water cooling system,
It is necessary to equip the cooling water supply circuit with a water supply valve and the cooling water discharge circuit with a drain valve. By the way, the present inventors
When the multilayer wiring board was pressed and bonded using a hot press equipped with the cooling water supply circuit and the cooling water discharge circuit described above, it was found that there was a place where the adhesive did not melt sufficiently and the multilayer wiring board warped. I knew that I could get tired or trap air inside and cause voids. Therefore, as a result of investigating the cause, the inventors have found that the water supply valve and the drain valve do not have a structure that can be completely shut off even in the shut-off state. It was found that it was caused by the fact that it flowed into the board side and the temperature near the cooling water supply port and discharge port of the hot plate became lower than in other parts. That is, during heating, since the hot plates 5 and 7 become high in temperature, the air in the cooling passages expands and the pressure rises, and the high-pressure air and leaked water in the pipes for cooling water supply and cooling water discharge. Since the heat tends to be accumulated in the center of the hot platen and becomes high pressure in the center of the cooling passage, it is impossible for the leaked water to go beyond the high pressure part to the outlet or inlet of the other party and lose the escape area. Moreover, it has been found that it is difficult to obtain a good multi-layered printed wiring board with less variation in adhesion, because the water leakage continues to increase and the temperature difference expands. In addition, since some cooling water remains in the cooling passages of the heating plate even after the completion of the bonding of the printed wiring board, the cooling water remaining during the heating in the next bonding process evaporates, and the pressure in the cooling passages increases. At the same time as rising
There is a problem that the heating rate decreases because heat energy is taken as vaporization heat.

[Object of the Invention]

The object of the present invention is to eliminate the non-uniformity of the temperature of the hot platen surface due to the cooling water leaking from the cold water valve and the drain valve, and to obtain a multilayer printed wiring board or the like with less variation in adhesion,
Another object of the present invention is to provide a hot press capable of increasing the heating rate of the heating plate.

[Outline of Invention]

The present invention, a lower bolster and an upper bolster arranged to face each other, a lower heating plate fixed to the upper surface of the lower bolster and an upper heating plate fixed to the lower surface of the upper bolster,
A ram cylinder that moves one bolster toward the other bolster is provided, and an adherend such as a multilayer printed wiring board is inserted between the lower heating plate and the upper heating plate, and both heating plates are heated by an electric heater. At the same time, one bolster is moved by the ram cylinder to pressurize and bond the adherends, while cooling both hot plates after the pressurizing and adhering process is completed, the cooling passage is provided with cooling water. In a hot press configured to be circulated, the cooling water that leaks from the water supply valve of the cooling water supply circuit and the drain valve of the cooling water discharge circuit into the cooling passage at the inlet and the outlet of the cooling passage and tries to enter the cooling passage. By providing a drain circuit that discharges
This is to eliminate the unevenness of the temperature on the surface of the heating plate due to the leaked cooling water.

Example of Invention

An embodiment of the present invention will be described below with reference to FIG. The drawing shows the configuration of a hot press according to the present invention, and the same reference numerals as those in FIG. 3 represent the same or corresponding ones. Reference numeral 12 denotes a cooling water supply circuit for supplying cooling water to each cooling passage (not shown) of the lower heating plate 5 and the upper heating plate 7, and includes a water supply valve 13 and a strainer 14. Reference numeral 15 is a cooling water source, 16 is a cooling water discharge circuit for discharging the cooling water flowing through the cooling passages of the lower heating plate 5 and the upper heating plate 7, and is provided with a strainer 17 and a drain valve 18. 19 is a water supply valve 13 and a drain valve
A drain circuit that removes the cooling water that leaks from 18 and enters the cooling passages of the upper and lower heating plates is connected to the cooling water discharge circuit 16 before the drain valve 18. In addition, the drain circuit 19 has a first
A drain valve 20, a second drain valve 21, and a strainer 22 are provided.

Next, the operation of this embodiment will be described.

When cooling the lower heating plate 5 and the upper heating plate 7, a cooling water supply circuit
The water supply valve 13 of 12 and the drain valve 18 of the cooling water discharge circuit 16 are opened, the cooling water flows through the strainer 14 and the water supply valve 13, flows through the cooling passage in the lower heating plate, and passes through the strainer 17 and the drain valve 18. Will be discharged. When the upper and lower heating plates are heated, the water supply valve 13 and the drain valve 18 are closed, and the flow of the cooling water to the cooling passage is shut off. At the time of this heating, the water supply valve 13 and the drain valve 18 are not structured to completely shut off the cooling water even when they are closed. Therefore, the cooling water leaks from these valves and the upper and lower heating plates 7, 5 It will enter the cooling passage. Therefore, when the first drain valve 20 and the second drain valve 21 of the drain circuit 19 are opened, the leaked cooling water is discharged to the outside through the drain circuit 19. As a result, no cooling water remains in the upper and lower hot plates,
Since the surfaces of the upper and lower heating plates have a uniform temperature distribution, it is possible to obtain a good multilayer printed wiring board with little variation in adhesion. Further, since the cooling water does not remain in the cooling passage, the heating rate of the heating plate can be improved.

FIG. 1 shows another embodiment of the present invention. The difference from FIG. 2 is that the drain circuit 19 before the first drain valve 20 has an air supply valve.
24 and a strainer 25 are connected to the air blow circuit 23, the air supply valve 24 is opened before the heating of the heating platen, and the air sent from the blower 26 is supplied to the upper and lower cooling plates of each cooling passage and the cooling water supply circuit.
12, the strainer 22 of the drain circuit 19 and the second drain valve 21 are circulated in this order to blow off the water droplets remaining in the cooling passage.

According to this embodiment, even water droplets remaining in the cooling passages of the upper and lower heating plates 7 and 5 can be removed, so that the heating speed of the heating plate can be further improved.

[Effects of the Invention] As described above, according to the present invention, since the cooling water that leaks from the water supply valve and the drain valve and tries to enter the cooling passage of the heating plate is removed via the drain circuit, The temperature distribution on the surface of the hot platen can be made uniform, and an adherend such as a multilayer printed wiring board with little variation in adhesion can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a hot press of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional hot press. 1 ... Lower bolster, 2 ... Upper bolster, 5 ... Lower heating plate, 7 ... Upper heating plate, 9 ... Ram cylinder, 12 ... Cooling water supply circuit, 13 ... Water supply valve, 16 ... Cooling Water drain circuit, 18 ...
… Drain valve, 19 …… Drain circuit, 20 …… First drain valve, 21
…… Second drain valve, 23 …… Aeblo circuit, 24 …… Air supply valve.

Claims (1)

[Claims] 1. A lower bolster and an upper bolster arranged to face each other, a lower heating plate fixed to an upper surface of the lower bolster and an upper heating plate fixed to a lower surface of the lower bolster, and one bolster. And a ram cylinder that moves the ram toward the other bolster, insert an adherend such as a multilayer printed wiring board between the lower heating plate and the upper heating plate, and heat both heating plates with an electric heater, While moving one bolster by a cylinder to pressurize and bond the adherend, cooling the both hot plates after the pressurizing and adhering process is passed through cooling water through a cooling passage provided in the hot plate. In the hot press configured as described above, the cooling water that leaks from the water supply valve of the cooling water supply circuit and the drain valve of the cooling water discharge circuit into the cooling passage at the inlet and the outlet of the cooling passage. Hot press which is characterized in that a drain circuit to be out.