JPH0528072U - Printed circuit board warp prevention structure - Google Patents

Abstract

(57) [Abstract] [Purpose] When the SMT parts, chip parts, etc. are mounted on both sides of the collective substrate and reflowed, the collective substrate does not warp due to heat. [Structure] A discarding substrate portion 4 is provided around the entire outer periphery of a collecting substrate portion 1 in which small substrates 2 are arranged in parallel, and only one of the vertical or horizontal division grooves 5 corresponding to the collecting substrate portion 1 is disposed. Provide up to the edge.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a board warp prevention structure when components are mounted on a multi-sided double-sided board and flowed or reflowed.

[0002]

[Prior Art]

 Conventionally, most of the printed circuit boards used mainly in industrial equipment, such as surveillance TV cameras, use double-sided boards with through-holes, and with the miniaturization of equipment, it is easy to handle small boards with high mounting density. It is often used as an aggregate substrate. An example of the process of mounting various components on the aggregate substrate is as follows. First, a solder paste is printed on the surface by a mask, SMT components, etc. are placed on the surface, and passed through a reflow oven such as far infrared rays. After the mounting process on the front surface, the adhesive is applied by the dispenser to the position where the chip parts are placed in the back surface process, the chip parts are mounted by the chip part mounting machine, and the adhesive is solidified through the drying oven. Perform post-flow soldering. After that, the board is washed and hand-soldered parts are attached and divided to complete the product.

[0003]

[Problems to be solved by the device]

 As described above, as shown in FIG. 2, in order to collect the small substrates 2 and to treat them as one large substrate 1, all the vertical and horizontal division grooves 3 are cut in a V shape and the front and back are aligned. Since it is provided up to the end of the discarded substrate 4, by mounting SMT parts etc. on the surface and passing it through a reflow oven, the substrate warps due to the split grooves due to heat, and due to the dispenser performed in the process on the back side. There was a problem that the application of adhesive and the mounting of chip parts by the chip part mounting machine were not performed accurately.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in a printed circuit board in which a waste board part having a required width is provided around the entire outer circumference of a collective board part in which small boards are arranged in parallel, Provided is a method for preventing warpage of a printed circuit board, characterized in that only one of vertical and horizontal corresponding dividing grooves for dividing a part is provided up to the end of the discarded substrate.

[0005]

[Action]

 As described above, in the printed circuit board in which the waste board portion having the required width is provided around the entire outer circumference of the collective board portion in which the small boards are arranged side by side, the waste board portion is divided from the waste board portion. By providing only one of the vertical or horizontal corresponding dividing groove to the end of the waste board, it is possible to easily mount the parts on the front and back of the collective board and then divide it into a small board. Since the dividing line does not pass through the provided waste board portion having the required width, the warpage due to the heat of the reflow furnace can be almost eliminated.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of an embodiment of a printed circuit board warp prevention structure according to the present invention.

In the figure, reference numeral 1 denotes an aggregate substrate portion in which small substrates 2 are arranged side by side through a dividing groove 3, and a waste substrate portion 4 having a required width is provided around the entire outer periphery of the aggregate substrate portion 1. Are provided through the dividing groove 5. Only one of the vertical and horizontal sides of the opposing dividing groove 5 is provided up to the end of the discarding substrate portion 4 so that the small substrate 2 can be divided and taken out. Further, these dividing grooves 3 and 5 are provided at positions where the front surface and the back surface are coincident with each other so that they can be easily divided.

[0008]

[Effect of the device]

 As described above, in the printed circuit board in which the waste board portion having the required width is provided around the entire outer circumference of the collective board portion in which the small boards are arranged side by side, the waste board portion is divided from the waste board portion. By providing only one of the vertical or horizontal corresponding dividing groove to the end of the waste board, it is possible to easily mount the component on the collective board and then divide it into small boards. Since there is no dividing groove in the waste board of the required width, the warpage due to the heat of the reflow furnace can be almost eliminated. It is remarkable that improving the value contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a printed circuit board warp prevention structure according to the present invention.

FIG. 2A is a plan view of an example of a conventional collective substrate;
FIG. 3B is a sectional view showing a warped state.

[Explanation of symbols]

 1 Assembly board part 2 Small board 3 Dividing groove 4 Discarding board part 5 Dividing groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Inoue 1116 Suenaga, Takatsu-ku, Kawasaki City Inside Fujitsu General Limited

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board, wherein a waste board portion having a required width is provided on the entire outer circumference of a collective board portion in which small boards are arranged side by side so that the waste board portion is divided from the collective board portion. A method for preventing warpage of a printed circuit board, characterized in that only one of the vertical and horizontal sides of the corresponding dividing groove is provided up to the end of the discarded circuit board.