JPH02214658A - Warping correction device for printed wiring board - Google Patents

Abstract

PURPOSE:To prevent cracks and cuts from generating and correct warping securely by applying vibration when warping of a printed wiring board is corrected while the printed wiring board is supported from both sides. CONSTITUTION:A warping correction means 2 is constituted of a lower supporting section 2a and a pressurizing unit 2b, and warping of a printed wiring board 1 is corrected by pressing downward respective four corners of an upper surface of the printed wiring board 1 by means of four pressurizing rods 2d constituting a pressurizing unit 2b in the state of retaining the center of lower surface of the printed wiring board 1 on the lower supporting section 2a and applying vibration by a vibrating means 3. Plastic deformation of the printed wiring board is accelerated by vibration by said arrangement when stress is applied to the printed wiring board 1 by the pressurizing unit 2b, and the warping can be corrected by comparatively small stress to prevent the printed wiring board 1 from getting cracked or cut out.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial 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 undergo heating, humidification,
Due to various external influences such as pressurization, warpage occurs to a greater or lesser extent.

Therefore, various studies have been made to correct the warpage of printed wiring boards.

In order to correct the warpage of the printed wiring board 1, for example, when the printed wiring board 1 has a convex warp on the bottom surface as shown in FIG. 2(a), the method is as shown in FIG. I turned it upside down, held the end in my hand, and bent it in the opposite direction to straighten it.

[Invention tries to solve 4! lj[] However, in the case of the above-mentioned warp which is manually re-curved, it is not only troublesome because it is done manually, but it is even more troublesome as the bending has to be repeated many times. However, to correct the warp by hand, you have to bend it strongly in the opposite direction to the warp direction, and if the surface is more than elastically deformed, you need to take into account the springback and apply force until it does not recover. When the printed wiring board 1 has perforations, V-cuts, etc., if it is bent more strongly than elastic deformation, it often cracks or chips, and there is a problem in that it cannot be corrected by any means.

Therefore, for example, as shown in FIG. 6, the back side of the printed wiring board 1 is supported by a support plate 10, and in this state, pressure is applied from above by a pressure device 11 to correct the warpage of the printed wiring board 1. However, in this case as well, it is necessary to bend the board beyond its elastic deformation and apply pressure until it fully recovers, taking springback into account.
If there are perforations, V-cuts, etc. in the material, bending it more strongly than elastic deformation will often result in cracking or chipping, resulting in problems that cannot be corrected.

The present invention has been made in view of the above points, and is capable of reducing deformation when stress is applied for straightening, thereby preventing cracks, chips, etc. of printed wiring boards, and ensuring reliability. It is an object of the present invention to provide a warpage correction device for a printed wiring board that can correct warpage.

[Means for Solving the Problems 1] The printed wiring board warpage correction device according to the present invention includes a warpage correction means 2 that supports a printed wiring board 1 from both sides and corrects warpage, and a warpage straightener vi2 that is vibrated. It is characterized by comprising a vibration means 3 for applying vibration, and by adopting such a configuration, the above-mentioned object of the present invention is achieved.

[Function l] Therefore, when correcting the warpage of the printed wiring board 1 while supporting the printed wiring board 1 from both sides with the warpage straightener Fi2, by applying vibration with the vibrating means 3, it is possible to print the printed wiring board by applying only a small stress. The plastic deformation of the wiring board has been accelerated and the warpage has been corrected.

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

FIG. 1 shows an example of the warpage correction IIA of the present invention. That is, the warp correction device is composed of a warp correction means 2 for straightening the printed wiring board 1 and a vibration means 3 for applying vibration during the correction.

In FIG. 1, the warpage correction means 2 is composed of a lower support portion 2a and a pressure unit 2b. Pressure 22) 2b is four pressure rods 2 with rubber material 2C provided at the lower end to prevent damage.
d, and the pressure unit 2b is vertically movable by a vertical drive mechanism (not shown). As the lower support part 2a, for example, a suction clamp that supports the printed wiring board 1 in a suction state is used, but it may also be a lower support part that simply supports the printed wiring board 1 on it. Vibration is applied to n2m by a vibration means 3 such as a vibrator.

On the other hand, the printed wiring board 1 to be corrected in the present invention has a board formed of a resin laminate. That is, prepreg is created by impregnating a base material such as glass cloth or paper with varnish of thermosetting resin such as epoxy resin or phenolic resin and drying it, and then multiple sheets of prepreg and metal foil such as INM are made. After creating a metal foil-clad laminate by stacking them and forming them under heat and pressure, the resin laminate can be used as a substrate by etching or drilling holes in the metal foil of the metal foil-clad laminate. A printed wiring board 1 can be obtained.

Therefore, in order to correct the warpage of the printed wiring board 1,
The printed wiring board 1 is supported from above and below by the warp correction means 2 while the warp is corrected by the warp correction means 2. In this case, the warp correction means 2 corrects the warp while the vibration means 3 applies vibration. That's what I do. That is, in the embodiment shown in FIG. 1, the warpage correction means 2 is composed of a lower support part 2a and a pressurizing unit 2b. While holding the center of the lower surface of the printed wiring board 1, the four pressure rods 2d forming the pressing unit 2b press the four corners of the upper surface of the printed wiring board 1 downward, and the vibration means 3 presses the four corners of the upper surface of the printed wiring board 1 downward. By applying vibration, the warpage of the printed wiring board 1 is corrected. In this case, by correcting the warp with the warp correction means 2 while applying vibration, when stress is applied to the printed wiring board 1 by the pressure (2) 2b, the printed wiring board 1 can be corrected by applying vibration.
The plastic deformation of the printed wiring board 1 is accelerated, and the deformation of the printed wiring board 1 under stress is reduced to 1/2 to 1/10 compared to when straightening the warp by hand. It is something that can be done. That is, FIG. 2(a) shows an example of the printed circuit board 1 before warping is corrected.
This printed wiring board 1 has a size of 30 cm x 30 cm, a thickness of 1.6 cm, and is curved in a 3-1 convex shape so that the lower surface side is convex. In order to correct the warpage of the printed wiring board 1, conventionally, as shown in Figure 2 (b), the printed wiring board 1 is held upside down, held by hand, and bent by about 30 degrees in the opposite direction to the warp. It was necessary to repeat this several times to correct the warping, but in the present invention, as shown in Fig. 1 above (
By applying vibration (IKHz) when the printed wiring board 1 shown in a) is turned upside down and the warp is corrected by the warp correction means 2, the deformation due to stress is within 10+ue as shown in Fig. 2 (e). The warp can be corrected by applying stress only once for about 1 to 10 seconds without repeatedly applying stress. In the present invention, the desired amount of warp may be corrected by constantly checking the amount of warp using a laser string distance gauge or a differential transformer, and the warp correction means 2 may be corrected while applying vibration in this way. In devices that correct warpage, the deformation under stress is small as described above, so even if V-grooves 6, perforations, etc. are formed on the printed wiring board 1 as shown in FIG. This means that it is possible to prevent the printed wiring board 1 from breaking at the 6 or perforation portions, and it is possible to correct warping even in the printed wiring board 1 having these grooves 6 or perforations.

FIG. 4 shows another embodiment of the invention.

In this embodiment, the warp correcting hand Pi2 is constructed of two plate-shaped spring steels 2e, and a vibration means 3 applies vibration to one of the spring steels 2e.

Then, the printed wiring board 1 to be straightened is held between the spring steels 2e from both sides, and in this state, the warp of the printed wiring board 1 is straightened by applying pressure as shown by the arrow in Fig. 4. However, when correcting the warpage, the vibrator stage 3 applies vibration while correcting the warpage. In this embodiment, warpage is corrected while supporting both sides of the printed wiring @ 1 with plate-shaped spring steel 2e, so this is particularly effective in the case of printed wiring board 1 with V grooves 6 and perforations. When stress is applied to straighten the warp, ■ Groove 6
This makes it possible to further prevent breakage from occurring at the perforations.

Further, FIG. 5 shows still another embodiment of the present invention. In this embodiment, the printed wiring board 1 is held between two plate-shaped spring steel sheets 2e constituting the warpage correction means 2, and is held in place by being held from both sides.In this state, pressure is applied as shown by the arrow in FIG. 5, and vibration is applied. In order to correct the warpage while applying vibration by the child stage 3, an elastic sealing member 4 is interposed between the outer peripheries of the two pieces of spring steel 2e, and a suction device r! connected to the spring steel 2e is inserted. 15, the air in the area surrounded by the two pieces of spring steel 2e and the sealing member 4 is sucked to create a slight vacuum, and the printed wiring board 1 and the spring steel 2e are brought into close contact with each other. Ah, and since the printed wiring board 1 and the spring steel 2e can be brought into closer contact with each other in this way, the printed wiring board 1 with V-grooves 6 and perforations can be made even more compact than the embodiment shown in FIG. This is effective and can further prevent breakage from the grooves 6 and perforations when stress is applied to correct warpage.

Effects of the Invention 1 As described above, the present invention includes a warpage correction means for correcting warpage by supporting a printed wiring board from both sides, and a vibration means for imparting vibration to the warpage correction means. When correcting the warpage of a printed wiring board while supporting the printed wiring board from both sides using the warpage correction means, the warpage can be corrected while applying vibration, and therefore, plastic deformation of the printed wiring board can be achieved by simply applying a small stress. It is accelerated and the warp is corrected, and the printed wiring board may be cracked during the warp correction.
This prevents chipping and allows for reliable correction of warpage.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, and FIGS. 2(a) and (b)
)(c) is a perspective view of a printed wiring board before warpage correction, an explanatory diagram of conventional warpage correction by hand, an explanatory diagram of warpage correction according to the present invention, and FIG. 3 is a printed wiring board with V-grooves. FIG. 4 is a cross-sectional view of another embodiment of the present invention, FIG. 5 is a cross-sectional view of still another embodiment of the present invention, and FIG. 6 is a cross-sectional view of a conventional example. 1 is a printed wiring board, 2 is a warpage correction means, and 3 is a vibration means.

Claims (1)

[Claims] (1) A warpage correction device for a printed wiring board, comprising a warpage correction means for correcting warpage by supporting the printed wiring board from both sides, and a vibration means for imparting vibration to the warpage correction means.