JPH0462860B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an apparatus for correcting warpage of a printed wiring board using a resin laminate as a substrate.

[Prior Art] Printed wiring boards are subjected to various external influences such as heating, humidification, and pressurization during the processing process, so that warpage occurs to a greater or lesser extent.

Therefore, various studies have been made to dehumidify the printed wiring board and correct the warpage of the printed wiring board.

Conventionally, the aging treatment was carried out by stacking the materials in multiple stages, one above the other, in a dryer, for example.

[Problems to be Solved by the Invention] However, in the case of dryers that are stacked vertically in multiple stages for aging treatment, because of the stacking, dehumidification can only be done from the end faces, resulting in insufficient dehumidification. There was also the problem that it took a long time (several hours).

The present invention has been made in view of the above points, and is capable of efficiently and reliably dehumidifying printed wiring boards and correcting warpage, and in addition, enables efficient and uniform heating of printed wiring boards. An object of the present invention is to provide a printed wiring board warpage correction device that can correct the warpage of a printed wiring board.

[Means for Solving the Problems] The printed wiring board warp straightening device according to the present invention includes a dehumidifying device B that dehumidifies a large number of printed wiring boards A in an upright state with gaps between them; A heating device C for straightening warpage that heats a large number of printed wiring boards A while standing upright with gaps between them.
and a press device D that presses the printed wiring board A heated by the heating device C to a state where the warp is corrected. By adopting such a configuration, the above-mentioned object of the present invention can be achieved. has been achieved.

[Function] Therefore, the dehumidifier B dehumidifies a large number of printed wiring boards A while standing upright with gaps between them, and dehumidifies each of the large number of printed wiring boards A evenly from both sides in a short time, and then the dehumidifier A large number of printed wiring boards B, which have been dehumidified in B, are placed upright with gaps between them and are efficiently heated in a heating device C to straighten the warpage, and then pressed in a press device D to straighten the warp. be.

[Example] The present invention will be described in detail below based on examples.

An embodiment of the present invention is shown in FIGS. 1-4. In FIG. 1, 1 is the main body of the apparatus, with a loading section 10 at the front, an unloading section 11 at the rear, and a dehumidifying device B and a heating device C between the loading section 10 and the unloading section 11 in order from the loading section 10 side. , a press device D are provided. The dehumidifying device B is formed by a circulating hot air dryer or the like in which a blower is driven by a motor, and is designed to uniformly dehumidify the printed wiring board A. The heating device C is also configured to uniformly heat the printed wiring board A by blowing hot air using a circulating dryer or the like whose blower is driven by a motor. In the drawings of FIGS. 1 and 2, a dehumidifying device B and a heating device C are connected, and an opening/closing partition 2 is provided between the dehumidifying device B and the heating device C. Also,
An inlet shutter 14 and an outlet shutter 1 are provided at the entrance of the dehumidifying device B and the outlet of the heating device C, respectively.
5 to open and close each. Further, a conveyor 3 formed by a birch conveyor is provided so as to extend from the carry-in section 10 through the dehumidifying device B and the heating device C to the carry-out section 11. Along the upper side of the conveyor 3, as shown in FIG. 3, several (for example, 11) guide bars 4 are arranged parallel to the conveyor 3 and are fixedly attached to a conveyor frame 18 or the like. Each guide bar 4 includes a carry-in side guide bar 4a provided in the carry-in section 10, and a dehumidifier internal guide bar 4 provided in the dehumidifier B.
b, a heating device internal guide bar 4c provided in the heating device C, and a delivery side guide bar 4d provided in the delivery section 11. In addition, the carry-in guide bar 4a, the dehumidifying device guide bar 4b, and the heating device guide bar 4c can also be formed as one continuous piece.

Further, a press device D is provided on the upper surface of the unloading section 11 between the heating device internal guide bar 4c and the unloading guide bar 4d. The press device D is formed by several (for example, 11) cooling plates 5, such as aluminum plates or stainless steel plates, whose front and back surfaces are polished to flat surfaces, and one end of each cooling plate 5 is One is a fixed cooling plate 5a, and the other is a movable cooling plate 5. Of these cooling plates 5, a fixed cooling plate 5a is fixed on the unloading section 11,
As shown in FIG. 4, a rod 21 projects horizontally from the fixed cooling plate 5a in a direction perpendicular to the guide bar 4.
Each movable cooling plate 5b is slidably passed through and suspended from the cooling plate 5, and a connecting device 22 such as a chain or wire is stretched between each cooling plate 5 to regulate the widening of the interval between each cooling plate 5. It's like this. For example, each cooling plate 5 is formed to have a thickness of 20 mm, and the length of the connector 22 is set so that the distance between each cooling plate 5 is 7 mm at maximum. As shown in FIG. 3, the tip of a rod 24 of a cylinder 6 such as an air cylinder is connected to a movable cooling plate 5b located at the end opposite to the fixed cooling plate 5a.
By operating the cylinder 6 and protruding the rod 24, each movable cooling plate 5a is pressed down in sequence, and conversely, by drawing the rod 24 into the cylinder 6, each movable cooling plate 5a is connected. It is designed so that it can be pulled apart in order by the action of the tool 22.

Here, the printed wiring board to be corrected in the present invention is one in which the substrate is formed of a resin laminate. That is, prepreg is created by impregnating a base material such as glass cloth or paper with a varnish of thermosetting resin such as epoxy resin or phenolic resin and drying it. After creating a metal foil-clad laminate by stacking foils and forming them under heat and pressure, the metal foil of this metal foil-clad laminate is further etched or perforated. A printed wiring board using a resin laminate as a substrate can be obtained.

However, when dehumidifying the printed wiring board of the lever and correcting the warpage, first
The printed wiring boards A are fed one by one onto the conveyor 3 between each guide bar 4a, and each printed wiring board A is separated and supported by the guide bar 4a, so that the printed wiring boards A are placed vertically on the conveyor 3.
A plurality of printed wiring boards A are set on top as one set. Since the printed wiring boards A are supported on the conveyor 3 in this upright state, a large number of boards (for example, 10 boards) can be set as one set, and production efficiency can be ensured. Even a small device can dehumidify a large number of printed wiring boards A at the same time and can also heat them for straightening them, making it possible to make the entire device compact. The printed wiring board A is then conveyed into the dehumidifier B by the running drive of the conveyor 3. Then, in this dehumidifier B, 80℃~
It dehumidifies by heating at 140℃ for 10 to 15 minutes. In the dehumidifier B, each printed wiring board A is supported by a guide bar 4b and held in an upright position, and in this state, warm air is blown from below to dehumidify it. Heat is circulated to both the front and back sides of the printed wiring board A located in the area, allowing for efficient and uniform dehumidification. Moreover, since there is a guide bar 4b between each printed wiring board A, a gap is created between each printed wiring board A, and the hot air is uniformly in contact with the entire surface of each printed wiring board A. A can be more uniformly dehumidified. When the dehumidification is completed, the opening/closing partition 2 is opened, the conveyor 3 is run, and a large number of printed wiring boards A are sent into the heating device C, where they are heated at 120° C. to 170° C. for 3 minutes. In heating device C, each printed wiring board A
is supported by a guide bar 4c and held in an upright position, and is heated in this state, but the printed wiring board A in an upright position receives heat efficiently and uniformly on both its front and back surfaces. It can be heated to. Moreover, since the guide bar 4c exists between each printed wiring board A, a gap is created between each printed wiring board A, and heat is uniformly distributed over the entire surface of each printed wiring board A. can be heated more evenly. As a result, the temperature difference between each part of the printed wiring board A is set to within 5°C, and the temperature difference between the front and back sides of the printed wiring board A is set to within 3°C. Further, the conveyor 3 is operated intermittently at predetermined time intervals, and several sets of printed wiring boards A are sequentially introduced into a dehumidifying device B and a heating device C to be dehumidified, and then heated to straighten the warp. However, at the stage when it is introduced into the heating device C from the dehumidifying device B, the first printed wiring board A, which has already been introduced into the heating device C, reaches a temperature higher than the glass transition point of the resin of the board. The printed wiring board A is now in a heated state, and at this point, the printed wiring board A is brought out from the heating device C to the unloading section 11 as the conveyor 3 is driven. Here, if the resin constituting the resin laminate serving as the substrate of printed wiring board A is, for example, epoxy resin, the glass transition point is
Since the temperature is 120 to 150°C, printed wiring board A is heated to a temperature higher than this temperature.

Each printed wiring board A that has been heated in this way and has come out to the unloading section 11 is attached to each guide bar 4c.
It is inserted and set between each cooling plate 5 arranged corresponding to the rear end. Then, the cylinder 6 is actuated, the rod 24 protrudes, and the movable cooling plates 5a are sequentially slid and pressed toward the fixed cooling plate 5b, and the printed wiring board A is pinched between the cooling plates 5, and the cooling plate 5a is pressed. Apply pressure with the flat surface of the printed wiring board A to correct the warpage. By heating the printed wiring board A to a temperature equal to or higher than the glass transition point of the resin and then applying pressure, it is possible to correct the warpage while removing the residual stress in the printed wiring board. For example, it is sufficient to apply pressure of 5 to 100 kg to printed wiring board A having a size of 30 cm x 50 cm. Also, in this way, the cooling plate 5 is connected to the printed wiring board A.
By bringing the printed wiring boards A into contact with the cooling plate 5, the heat of the printed wiring boards A is absorbed and radiated by the cooling plate 5, and each printed wiring board A can be cooled to a temperature below the glass transition point and further printed. It is possible to cool the wiring board A to a temperature of 50 to 60°C at which it can be handled. Thereafter, the cylinder 6 is operated again to draw the rod 24 into the cylinder 6, and each movable cooling plate 5b is successively separated by the action of the coupling tool 22 and returned to its original state. Then, as the conveyor 3 operates, each printed wiring board A between the cooling plates 5 is moved from between the cooling plates 5 to between the guide bars 4d and carried out, and one set of printed wiring boards coming out from the heating device C next. Wiring board A is inserted between cooling plates 5 and set. Thereafter, in the same manner, the printed wiring boards A that are sequentially carried into the carry-in section 10 are dehumidified by the dehumidifying device B, then heated by the heating device C, and then cooled while being pressurized by the press device D to dehumidify and straighten the warpage. The printed wiring boards A can be sequentially carried out from the carry-out section 11.

When printed wiring board A is heated to a temperature above the glass transition point of the resin to correct the warpage as described above, and then cooled to a temperature below the glass transition point, the printed wiring board dehumidifies. At the same time, the warp is fixed in the corrected state, and the warp can be reliably corrected without returning the warp. for example
In a printed wiring board with a size of 250mm x 300mm
A 1.0mm warp can be corrected to 0.1mm or less.

Another embodiment of the invention is shown in FIG.
In this embodiment, a dehumidifying device B and a heating device C are separated. In addition, in this embodiment, the dehumidifier B
An example in which dehumidification is performed is shown. That is, in the example shown in FIG. 5, the transfer device E is placed next to the dehumidifying device B, the heating device C is placed next to the transfer device E, and the press device D is placed next to the heating device C. be. That is, press device D
The maximum number of printed wiring boards A that can be pressed at one time is about 10 due to constraints such as precision and efficiency. Sequential dehumidifier B
When printed wiring boards A made up of 50 boards are dehumidified by dehumidifying device B and exit from the outlet of dehumidifying device B, they are transferred to a transfer device E as a set of 10 boards, and then The sheets are sent to a heating device C to be heated, and then pressed in a press device D in sets of 10 sheets. Here, the transfer device D may be disposed next to the heating device C, and in this case, the heating device C can also heat 50 sheets as one set. In addition, in FIG. 5, a large number of round bars 7 are erected horizontally on the conveyor 3 in the dehumidifying device B, and a printed wiring board A is erected between the round bars 7 as shown in FIG. It is positioned and fed using a push member 8.

Another embodiment of the dehumidifier B is shown in FIG. That is, in each of the above-mentioned embodiments, an example in which the dehumidifier B is linear is shown, but in the case of a linear shape, a large space is required for the installation area of the dehumidifier B. In the embodiment shown in FIG. 6, the installation area of the dehumidifying device B can be reduced by making the line of the dehumidifying device B a line that circulates while meandering up and down. In FIG. 6, inside the dehumidifying device B, there is a line L that circulates in a meandering manner up and down as indicated by the arrow, and a large number of cars F move along this line L. Then, put a large number of printed wiring boards A (for example, a set of 30 boards) into the car F from the part A in Fig. 6, which is the entrance to the dehumidifier B. A guide bar is provided to support the board A in an upright position.While moving along the line L, the dehumidifier B
Take it out from part B in Figure 6, which is the exit of
A set of 30 printed wiring boards A is transferred to a heating device C, which is the next process, as a set of 10 boards by a transfer device (the transfer device is not shown in Fig. 6).
The heating device C then sends the press device D to the press device D. Further, in FIG. 6, the heating device C and the press device D are omitted.

[Effects of the Invention] As described above, the present invention includes a dehumidifying device that dehumidifies a large number of printed wiring boards in an upright state with gaps between them, and a dehumidifying device that dehumidifies a large number of printed wiring boards that have been dehumidified by the dehumidifying device through a gap. The system consists of a heating device for straightening warpage that heats the printed wiring boards while they are standing upright, and a press device that applies pressure to correct the warping of the printed wiring boards heated by the heating device. It is possible to dehumidify the printed wiring board efficiently and reliably by uniformly dehumidifying the air.
Further, it is possible to efficiently and uniformly heat a dehumidified printed wiring board in an upright state in order to correct the warpage, and then press it with a press device to ensure correction of the warp.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a schematic front view of the same, Fig. 3 is an exploded perspective view of a part of the same device, and Fig. 4 is a part of the same device. 5A and 5B are a schematic sectional view and a perspective view of a conveyor portion of another embodiment of the present invention, and FIG. 6 is a schematic perspective view of another embodiment of the dehumidification device of the present invention. A is a printed wiring board, B is a dehumidifier, C is a heating device, and D is a press device.

Claims (1)

[Claims] 1. A dehumidifying device that dehumidifies a large number of printed wiring boards standing up with a gap in between, and a heating device for straightening warpage that heats a number of printed wiring boards that have been dehumidified by the dehumidifying device while standing up with a gap in between. 1. An apparatus for correcting warpage of a printed wiring board, comprising: a press device that presses a printed wiring board heated by a heating device to a state where the warp is corrected;