JPH0440120B2 - - Google Patents

Description

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

[Prior art]

A conventional multi-stage hot press used for bonding multilayer printed wiring boards presses and heats a multilayer printed wiring board 2 held between jig plates 1 as shown in FIGS. 1 and 2. A hot plate 3, an intermediate hot plate 4, a lower hot plate 5, a heat insulating plate 7 that insulates the heat of the upper hot plate 3 from the press frame 6, and a ram 9 of a ram cylinder 8 that uses the heat of the lower hot plate 5 as a pressurizing source. The main components are a heat insulating plate 11 that insulates the upper lower bolster 10, a thrust guide 12 that guides the intermediate hot plate 4 and the lower hot plate 5, a guide rail 13 fixed to the press frame 6, and the work of the intermediate hot plate 4. It is composed of an arm 14 attached to a thrust guide 12 that determines a setup position, and a stopper 15 attached to a press frame 6 that receives the arm 14.

Next, the operation of the press will be explained. First, when the ram 10 is lowered to the lowest position and the intermediate heating plate 4 is placed on the stopper 15 as shown in FIG. 1, the multilayer printed wiring board 2 is placed between the jig plates 1 is inserted between each hot plate, and sends pressure oil to the ram cylinder 8 to raise the ram 9, passing through the intermediate hot plate 4 to the upper and lower hot plates 3,
A multilayer printed wiring board is formed by applying pressure and heating for 5 minutes.

The life of a press for stacking and bonding multiple layers of printed wiring boards is to maintain uniform temperature and pressure distribution, which creates multilayer printed wiring boards with little variation in dimensional changes.

In order to obtain uniform temperature and pressure distribution, it is necessary to improve the mechanical parallelism of the pressurizing section and apply pressure uniformly. However, it is difficult to apply uniform pressure due to the effects of warping of the jig plate 1 due to thermal cycles, variations in the thickness distribution of the adhesive substrate, insertion position of the printed circuit board (misalignment with the center of the ram), distortion of the frame, etc.

Therefore, in the multi-stage adhesive hot press, a slide guide mechanism is added to the intermediate hot plate 4 as shown in FIG. This mechanism utilizes the isotropy of the coefficient of thermal expansion of the hot plate, and the slide angle θ is determined by the mounting position of the slide guide as shown in equation (1), so that even if the hot plate changes in temperature, it will not slide θ= tan ^-1 Lh/Ll...(1) The gap δ is kept unchanged. Furthermore, in order to regulate the inclination α between the hot plates, as is clear from FIG. 3, the gap δ between the guide surfaces must be made small and the guide width H must be made large relative to the guide interval L. However, by reducing the gap δ in the guide part,
There is a mechanical limit to increasing the guide width H, and it is difficult to regulate the parallelism between the hot plates to 0.05/500 mm or less.

[Purpose of the invention]

In view of the above points, an object of the present invention is to enable the parallelism between hot plates into which multilayer printed wiring boards are inserted to be constantly corrected during bonding.

[Summary of the invention]

Detect gaps at multiple locations between a set of hot plates,
The parallelism of the hot plate is corrected by a hot plate attitude control cylinder installed near the gap detector of the lower movable hot plate of the set of hot plates. This amount of correction is determined by taking the value detected by the gap detector into the control unit, calculating the parallelism to obtain the amount of parallelism correction, and then converting the correction amount into pressure, which is applied to the pressure control valve of the cylinder for controlling the attitude of the hot plate. It outputs a command value to and controls the posture of the hot plate using the pressure difference.

In addition, the relationship between the clearance correction amount and the pressure value is stored in the control device, and if a malfunction occurs (for example, a foreign object gets caught between the hot plates) and correction is not possible, a warning is sent to the operator. Add functionality.

[Embodiments of the invention]

Embodiments of the press of the present invention will be described below with reference to FIGS. 4 to 6. 4 to 6, the same reference numerals as in FIG. 1 indicate the same parts. The multi-stage adhesive press of the present invention includes a press main body part 16 and a heating device part 1.
7, a hydraulic device 18, a control section 19, and the like.

The press main body 16 includes an upper heating plate 20, an intermediate heating plate 21, and a lower heating plate 22 that press and heat the object to be adhered, and a heat insulating plate 23 and a lower heating plate 22 that insulate the heat of the upper heating plate from the press frame 25. It consists of a heat insulating plate 24 that insulates the heat from the lower bolster 26, a thrust guide 27 guided by the intermediate heating plate 21 and the lower heating plate 22, and a guide rail 28 fixed to the press frame 25,
A displacement detector 29 is attached between each hot plate, and three seat plates 30 are attached to the intermediate hot plate, which are connected to a cylinder rod 32 of a hot plate attitude control cylinder 31.

The heating device section 17 includes a plurality of control valves and controllers for heating and cooling, and is connected to a hot plate. The hydraulic system 18 similarly includes valves for pressure control, switching, speed control, etc., piping, a hydraulic pump 33, etc., and controls the hot plate attitude via a ram cylinder 8 that operates the lower bolster 26 and a pressure control valve 35. It is connected to the cylinder 31.

The control unit 19 has an interface in the operation panel 36 for operating this device that receives and receives signals from the displacement detector 29, control amount data, and pressure signals that electrically transmit calculation results to the pressure control valve 35 of the hydraulic system. Part 37,
It has a built-in control section 41 composed of an arithmetic device section 38, a storage device section 39, and a control device section 40 that controls these.

Next, the operation of the press of the present invention will be explained. Prior to starting the multi-stage press, first, the electric oil pump 33 of the hydraulic system is driven, the hot plate is set to the starting state according to the heating conditions, and the control panel 36 is also set to the operation preparation conditions. When the starting conditions for each device are met, a substrate to be bonded is inserted between each hot plate, and operation is started.

When the pressurized oil from the electric oil pump 33 is supplied to the ram cylinder 8 at the same time as the start of operation, the ram 9 starts to rise, and the substrate 2 to be adhered is pressurized and heated by the hot plate. At this time, the lower hot plate 22 and the intermediate hot plate 21 are guided by a slide guide 27 and a guide rail 28 fixed to the press frame 25. After the pressurization by the ram 9 of the ram cylinder 8 is completed, the displacement between the hot plates is detected by the displacement detector 29, and the amount of displacement between the hot plates is detected by the interface section 37 of the controller 41.
The data is then taken into the arithmetic unit 38.

l ₁ ^- _x = (l ₁₁ + l ₁₂ l ₁₃ )/3 …(2) l ₁₁ −l ₁ ^- _x = δ ₁₁ …(3) l ₁₂ −l ₁ ^- _X = δ ₁₂ …(4) l ₁₃ − l ₁ ^- _X = δ ₁₃ ...(5) where l ₁₁ - ₁₃ : Displacement amount of the 1st stage l ₁ ^- _x : Average displacement of the 1st stage δ ₁₁ - δ ₁₃ : Correction of each measurement point of the 1st stage The calculation unit 38 calculates equations (2) to (5) (same for other stages) for each interval between hot plates, and calculates the displacement correction amount δ and the attitude control cylinder in advance as shown in Fig. 7. A pressure relational expression is stored in the storage unit 39, and from the calculation result δ and the data of this relational expression,
The correction pressure of the attitude control cylinder 31 near the displacement measurement position is determined, and the pressure control valve 35 of each hot plate attitude control cylinder 31 of the hydraulic device 18 is instructed to adjust the parallelism between the hot plates by the hot plate attitude control cylinder 31. This is to be corrected.

Additionally, if a foreign object is caught between the hot plates, the output of the ram cylinder 8 will generally be lower than the output of the attitude control cylinder 3.
Since the output is much larger than that of No. 1, it is impossible to correct the attitude of the hot plate. The method for detecting this state is such that the calculation unit determines that the amount of displacement between the hot plates exceeds a certain value and correction is no longer possible, and generates an alarm signal to notify the operator.

According to this embodiment, the dynamic parallelism between the hot plates is controlled to change depending on the warping of the jig carried into the adhesive press, the carrying position, etc. of the laminated substrate, and any carrying method or treatment is possible. Uniform pressure can be applied even depending on the condition of the ingredients, an increase in mechanical clearance, etc., and as a result, uniform heating can be achieved. As a result, the laminated board undergoes uniform dimensional shrinkage, and a highly reliable multilayer printed wiring board is completed. That is, the variation in dimensional change of the bonded multilayer printed wiring board can be reduced by about 50% compared to the conventional press-formed board.

〔Effect of the invention〕

According to the multi-stage hot press of the present invention, the dynamic parallelism between the hot plates can be maintained with high accuracy during pressurization and heating of the adherend.

Therefore, it is highly effective in bonding objects such as multilayer printed wiring boards.

[Brief explanation of drawings]

Figure 1 is a front view showing the structure of a conventional multi-stage hot press, Figure 2 is a sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view taken along the line -
The figure is a diagram for explaining the relationship between the gap and the inclination of the hot plate guide part, Figure 4 is a front view showing the structure of the multi-stage hot press of the present invention, Figure 5 is a sectional view taken from the side shown in Figure 4, and Figure 6 7 is a system diagram of the hydraulic system in the multi-stage hot press of the present invention, and FIG. 7 is a graph showing the pressure and displacement correction amount δ of the hot plate attitude control cylinder in the multi-stage hot press of the present invention. 1...Jig board, 2...Multilayer printed wiring board to be bonded, 3...Upper heating plate, 4...Intermediate heating plate, 5...Lower heating plate, 7...Insulating board, 8...Ram cylinder, 9...
... Ram, 11 ... Heat insulation plate, 16 ... Press body section, 17 ... Heating device section, 18 ... Hydraulic device, 1
9...Control unit, 20...Upper heating plate, 21...Intermediate heating plate, 22...Lower heating plate, 23, 24...Insulating plate, 2
9...Displacement detector, 31...Hot plate attitude control cylinder, 32...Cylinder rod, 33...Hydraulic pump, 35...Pressure control valve, 36...Operation panel,
37...Interface section, 38...Arithmetic device section, 39...Storage device section, 40...Control device section,
41...Controller.

Claims (1)

[Claims] 1. In a multi-stage hot press in which an object to be bonded is inserted between hot plates and the bonded object is crimped by heating and pressurizing, a plurality of displacement detectors for detecting displacement between the hot plates, and a movable one of the hot plates are used. The parallelism correction amount of the hot plate is determined based on the detection signal from the hot plate attitude control cylinder connected to the side hot plate and the displacement detector, and the control pressure of the hot plate attitude control cylinder is determined from this correction amount. is calculated so that the control cylinder maintains the dynamic parallelism during pressurization and heating of the hot plate, and when the detection signal from the displacement detector exceeds a predetermined value, the parallelism is corrected. A multi-stage hot press characterized in that it is equipped with a control section that issues an alarm when it becomes impossible.