JPH0562068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a hot press suitable for bonding multilayer printed circuit boards of various electronic devices such as computers by applying pressure and heating.

[Background of the invention]

Conventionally, as shown in Japanese Patent Application Laid-open No. 59-215299, deformation of the heat insulating board and the bolster was absorbed by a buffer plate interposed between the bolster and the heat insulating board in a hot press to obtain a multilayer printed circuit board with a uniform thickness. An auxiliary ram inserted into the center of the hot plate on the buffer plate side of the bolster applies deformation to the buffer plate in the opposite direction to that of the heat insulating plate and the bolster, thereby creating a parallel state between the hot plates. A method of applying heat and pressure while heating is known.

With this method, if the bonding conditions are within a certain range, such as the size of the object to be bonded and the pressure applied, then by determining the optimal auxiliary ram diameter and auxiliary ram supply pressure, it is possible to create multiple layers of uniform thickness with simple operations. A printed circuit board is obtained.

However, when the bonding conditions change over a wide range, it is necessary to change the auxiliary ram cylinder diameter or the supply pressure each time, which poses problems such as requiring multiple operations.

[Purpose of the invention]

An object of the present invention is to provide a hot press that can apply an optimal pressure distribution to a bonded object with simple operation under a wide range of bonding conditions. [Summary of the Invention] The present invention achieves the above object. In order to do this, a plurality of auxiliary ram cylinders are provided symmetrically to the center of the hot plate, and the pressure generated when bonding the objects to be bonded is detected by a plurality of pressure detectors, and the pressure distribution is calculated from the pressure by a control device. The amount of deviation between the optimal pressure distribution according to preset bonding conditions and the pressure distribution is calculated, and the auxiliary ram cylinder is controlled so that this amount of deviation is minimized.

An example of the hot press of the present invention is shown below in Fig. 1.
This will be explained with reference to FIGS. 2 and 3.

The hot press of the present invention mainly includes a press body 1, a hydraulic device 2, a heating/cooling device 3, a control device 4, and the like.

In the press main body 1, a lower bolster 8 is placed on a ram 7 of a main ram cylinder 6 fixed to a lower press frame 5, and a lower heating plate 10 is mounted on the lower bolster 8 via a lower heat insulating plate 9. Tightening bolt 11
is fixed. Further, the intermediate hot plate 12 is supported by a counter cylinder 13, and the upper hot plate 14 at the top is thermally insulated by an upper heat insulating plate 15. Further, the upper bolster 20 has oil passages 18, 19 into which the auxiliary ram cylinders 16, 17, which serve as means for absorbing deformation of the heat insulating plate, are fitted so as to be movable in the vertical direction. There is. The buffer plate 21 receives the thrust of the ram cylinders 16 and 17 using the outer periphery of the upper bolster 20 as a fulcrum to apply smooth pressure distribution to the upper heat insulating plate 15, and is supported by tightening bolts 22. The lower frame 5, which houses the main ram cylinder 6 and the ram 7, has a support 23 and nuts 24, 25.
It is supported by etc.

In the above embodiment, the upper bolster 20 has been described, but the lower bolster 8 may also be used, and in a hot press with three or more stages, it is necessary to provide the upper and lower bolsters, respectively.

The heating and cooling device 3 includes a steam supply source 26, a cooling water supply source 27, a heating and cooling medium switching valve 28, a temperature regulator 29, and the like.

The hydraulic system 2 also includes an oil pump 30, a main ram pressure control valve 31, an oil cooler 32, a counter cylinder pressure adjustment valve 33, auxiliary ram pressure reducing valves 34, 35, and the like.

The control device 4 includes a plurality of pressure detectors 36, 37 attached to the buffer plate 21 of the press body 1, a converter 38, amplifiers 39a, 39b, 40a, 40b,
It is composed of data input/output devices 41, 42, a microcomputer 43, and the like.

Next, the operation of the hot press of the present invention will be explained.

First, an object to be bonded 44 such as a multilayer printed wiring board is inserted between the lower hot plate 10 and the intermediate hot plate 12 and between the intermediate hot plate 12 and the upper hot plate 14.
0, 12, 14 from the heating/cooling device 3, and at the same time, hydraulic pressure is supplied from the hydraulic device 2 to the main ram cylinder 6, and each hot plate 10, 1
2 and 14. At this time, control hydraulic pressure is supplied to the counter cylinder 13 in order to compensate for the weight of the hot plate itself. Also,
The pressure detector 3
6 and 37 detect the pressure of the object to be adhered 44, and this detected value is taken into the control device 4. The control device 4 calculates a pressure distribution from the pressure, and also calculates the amount of deviation (deviation pressure distribution) between this pressure distribution and an optimal pressure distribution according to preset bonding conditions.

Further, the control device 4 supplies hydraulic pressure corresponding to the deviation amount to the auxiliary ram cylinders 16 and 17 via the pressure reducing valves 34 and 35. At this time, with the thrust of the auxiliary ram cylinders 16 and 17, the buffer plate 21 is deformed toward the upper heat insulation plate 15 into the optimal convex shape calculated by the control device 4, using the nut 25 as a fulcrum, so that the upper heat insulation plate 1
5 receives this deformation, prevents concave deformation occurring on the side of the object to be bonded 44, and makes the thickness of the object to be bonded 44 uniform. The control oil pressure for the auxiliary ram cylinders 16 and 17 is calculated by the following procedure.

First, the detected pressures of the pressure detectors 36 and 37 shown in FIG.
The detection positions of the pressure detectors 36 and 37 stored in
The microcomputer 43 calculates the pressure distribution shown by the dotted line in FIG. Next, the calculated pressure distribution is compared with the optimal pressure distribution according to the bonding conditions etc. stored in the microcomputer 43 in advance (solid line in FIG. 3), and the deviation amount is minimized. The set values of the auxiliary ram cylinder pressure reducing valves 34 and 35 are controlled by the amplifiers 40a and 40b via the data input/output device 42. As a result, the buffer plate 21 is displaced by the reaction force of the auxiliary ram cylinder so as to approximate the optimum pressure distribution, thereby making the adherend 44 uniform in thickness.

In addition, if the flow time of the prepreg, which is the adhesive sheet of the adhered object 44, is input into the control device 4, and the buffer plate 21 is deformed into a more convex shape than usual when the prepreg is flowing, the resin of the fluid will be By causing the object 44 to flow from the center to the outer circumference due to the pressure difference and cross-sectional area difference between the center and the outer circumference of the multilayer printed wiring board, internal air bubbles that cause insulation defects can be removed to the outside.

According to this embodiment, by using multiple surface pressure detection and optimal surface pressure control functions and a plurality of auxiliary ram cylinders, it is possible to cause the buffer plate 21 to be optimally convexly deformed, and the heat insulating plates 9 and 15 can be deformed into a concave shape. Since it can absorb deformation, it has the effect of eliminating residual air bubbles when bonding multilayer printed wiring boards, producing wiring boards with high flatness accuracy, and reducing variations in dimensional changes of wiring boards.

〔Effect of the invention〕

The hot press of the present invention can accommodate a wide range of bonding conditions for objects to be bonded, and can apply an optimal pressure distribution to objects by simply setting conditions on the control device, thereby reducing dimensional changes. It becomes possible to mold objects to be adhered with few remaining air bubbles.

Therefore, when the object to be bonded is used for bonding work of multilayer printed wiring boards, for example, a great effect is exhibited.

[Brief explanation of drawings]

Fig. 1 is a front view showing the structure of the hot press of the present invention and a control system diagram for hydraulic pressure and heating/cooling, Fig. 2 is a system diagram of the control device, and Fig. 3 shows the detected pressure distribution of the auxiliary ram cylinder and the auxiliary ram cylinder. FIG. 3 is a diagram for explaining a set pressure distribution. DESCRIPTION OF SYMBOLS 1... Press body, 2... Hydraulic system, 3... Heating/cooling device, 4... Control device, 5... Lower frame, 6... Main ram cylinder, 7... Ram, 8...
...Lower bolster, 9...Lower heat insulating plate, 10...Lower hot plate, 12...Middle hot plate, 14...Upper hot plate, 15...
...Top insulation board, 16, 17...Auxiliary ram cylinder, 20...Top bolster, 21...Buffer board, 2
3... Strut, 36, 37... Pressure detector.

Claims (1)

[Claims] 1. In a hot press in which an auxiliary ram cylinder is fitted into a bolster so that it can move in the direction of pressing an object to be adhered, and the object to be adhered is heated and pressurized between hot plates,
a plurality of pressure detectors for detecting the pressure generated in the auxiliary ram cylinder during adhesion of the adherend; a pressure distribution is calculated from the pressure detected by the detectors; and the pressure distribution is preset. 1. A hot press, comprising: a control device that calculates an optimum deviation amount of pressure distribution according to bonding conditions; and the auxiliary ram cylinder is controlled so that the deviation amount is minimized.