JPH08181459A - Metal cap caulking mounting structure of small-sized electronic element on printed circuit board - Google Patents

Abstract

PURPOSE: To eliminate the shrink of a brazing material, to reduce the cost, to obviate the reflow heat damage of a printed circuit board and to obtain a method which does not need a jig to fix a cap by fundamentally eliminating a reflowing step, and brazing by once reflowing even when the brazing is required. CONSTITUTION: A caulking hole 6 of partial cut is provided at the peripheral edge of the printed circuit board 1 of a small-sized electronic element, a wide terminal leg 7 of an end is provided at the position corresponding to the hole 6, forced in the hole 6, and caulked fixedly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for caulking a small electronic element on a printed circuit board by caulking a metal cap.

[0002]

2. Description of the Related Art Conventionally, in order to mount a metal cap on a printed circuit board of a small electronic element, the printed circuit board 1 shown in FIG. 21a or a method such as that disclosed in Japanese Patent Laid-Open No. 3-85793 is used. To the circuit board, braze the metal cap 2 shown in FIG. 21b as shown in FIG. 21c, or
Alternatively, the printed circuit board 1 having the insertion holes 3 on the periphery as shown in FIG. 22a is reflowed, and the leg 4 made of stainless steel or nickel alloy shown in FIG. 22b, which is plated with copper alloy + Ni or Sn or the like. The attached metal cap 5 is covered as shown in FIG. 22C, and the leg 4 is inserted into the insertion hole 3 in the peripheral edge of the printed circuit board 1 for reflow. As a similar example, there is JP-A-2-285695. By the way, in the mounting method of the metal cap described above, the reflow process is performed twice before the cap is mounted, and the sink mark of the brazing material occurs the second time. Also, the two reflow processes result in a cost loss. In addition, the printed circuit board is subject to two reflow heat damages. In addition, a separate jig was required for temporarily fixing the cap 2 and the cap 5.

[0003]

Therefore, according to the present invention, basically, the reflow process is eliminated, and even if temporary brazing is required, brazing is performed by one reflow, the occurrence of sink marks of the brazing material is eliminated, and the cost is reduced. In addition, the printed circuit board reflow heat damage is eliminated, and a metal cap caulking mounting structure for a small electronic element on a printed circuit board that does not require a jig for fixing the cap is further provided. is there.

[0004]

In order to solve the above-mentioned problems, a metal cap caulking mounting structure of a small electronic element on a printed circuit board according to the present invention has a partial cut on a peripheral portion of the printed circuit board of the small electronic element. A caulking hole is provided, and a terminal tip with a wide tip is provided at a position corresponding to the caulking hole at the peripheral portion of the metal cap, and the terminal leg is press-fitted into the caulking hole to be caulked and fixed. It is a feature. The printed circuit board is made of an inorganic or organic material and has circuits on one side, both sides, or multiple layers. The metal cap is made of a bendable metal, and has a surface plated with brazing or cap protection.

[0005]

As described above, in the metal cap caulking mounting structure for a small electronic element of the present invention on a printed circuit board, a partially cut caulking hole formed in the peripheral portion of the printed circuit board is provided with the above-mentioned metal cap peripheral portion. Since the wide tip of the wide tip of the tip provided at the position corresponding to the caulking hole is press-fit and fixed by caulking, the reflow process is eliminated, and even if temporary brazing is required, brazing can be done with one reflow. The occurrence of sink marks on the brazing material is eliminated. Further, the cost is reduced by eliminating the reflow process. Furthermore, reflow heat damage to the printed circuit board is eliminated. In addition, no jig is needed to fix the metal cap.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a caulking mounting structure of a small electronic element on a printed circuit board according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the outline of a printed circuit board 1. In the peripheral portion, that is, in the middle of the four sides, through holes for caulking 6 of through holes, which are partially cut round holes, are provided. Corresponding to this, terminal legs 7 having wide tip portions are provided on the peripheral portion of the metal cap 2 of FIG. 2, that is, on the middle lower side of the four sides. The terminal leg 7 is press-fitted into the caulking hole 6 as shown in FIG. 3 and is caulked and fixed.

Next, another embodiment will be described with reference to the drawings. FIG. 4 is a perspective view showing the outline of the printed circuit board 1. In the peripheral portion, that is, in the middle of the four sides, there are provided through holes 8 for caulking through holes, each of which is a partially cut long hole. Correspondingly, a pair of terminal legs 9a and 9b are provided at the peripheral edge of the metal cap 2 in FIG. 5, that is, on the lower middle side of each of the four sides, and the outer ends of the tip ends of the pair of terminal legs 9a and 9b are provided. It is bulging laterally and wide. The terminal legs 9a and 9b are press-fitted into the caulking hole 8 as shown in FIG. 6 and fixed by caulking. The width dimension of the tip end portion 7a of the terminal leg 7 of the metal cap 2 and the bulging portion width dimension of the pair of terminal legs 9a and 9b are set to a as shown in FIGS. The inside diameter of the caulking holes 6 and 8 is b as shown in FIGS. 9 and 10, the opening width of the outer edge is c, and the length of the terminal leg 7 of the metal cap 2 and the pair of terminal legs 9a and 9b is d. And the thickness of the printed circuit board 1 is e, these dimensions are a>b> c and d ≦ e. Specifically, a =
0.7 mm, b = 0.6 mm, c = 0.4 mm, d, e = 0.8 mm. The caulking holes 6 and 8 of the partially cut through hole of the printed circuit board 1 are formed by cutting the outer shape of the printed wiring board P shown in FIGS. 11 and 12 which is created through drilling to plating pattern formation at a dotted line portion. What is done,
The outer shape is cut by any of die processing, router processing, shearing processing, laser processing, and the like.

According to the metal cap caulking mounting structure of each of the above embodiments, the terminal leg 7 is provided in the caulking holes 6 and 8.
13 and the widened portion of the pair of terminal legs 9a and 9b are shown in FIG.
And, as shown in FIG. 14, pressure contact is made, so that the electrical connection is surely made. Also, the caulking holes 6 and 8 are
Since it is formed by partially cutting and leaving about 1/2 or more and about 4/5 of the through hole, the opening edge becomes an overhang, and the terminal leg 7 and the pair of terminal legs 9a and 9b are displaced to the outside of the printed circuit board 1. Absent. However, a brazing material for soldering or the like is plated in the caulking holes 6 and 8 in advance, and the terminal leg 7 of the metal cap 2 and the pair of terminal legs 9a and 9 are formed.
By pre-plating brazing material on b, caulking +
Even when brazing is required, it can be brazed at the same time as other mounting parts by one reflow.

The shapes of the terminal leg 7 of the metal cap 2 and the pair of terminal legs 9a and 9b are not limited to those of the above-described embodiment, and the wedge shapes shown in FIGS. 15 and 16 are shown in FIGS. The outer peripheral tooth shape shown and the eyelet shape shown in FIGS. 19 and 20 may be used. In short, any shape may be used as long as it can be easily inserted into the caulking holes 6 and 8 and has an anchor effect that makes it difficult to pull out after caulking. Further, the caulking holes 6 and 8 are independent, but they may be combined. Also, printed circuit board 1
However, in the case of having a circuit only on one side, the caulking holes 6 and 8 are formed by partially cutting non-through holes.

[0010]

As can be seen from the above description, according to the caulking mounting structure of the small electronic element on the printed circuit board of the present invention, the reflow process is eliminated, and even if brazing is required, one reflow is required. Since it can be brazed, the sink mark of the brazing material does not occur, the cost is reduced by eliminating the reflow process, the reflow heat damage of the printed circuit board is eliminated, and no jig is required to fix the metal cap Becomes

[Brief description of drawings]

FIG. 1 is a perspective view of a printed circuit board in an embodiment of a metal cap caulking mounting structure of the present invention.

FIG. 2 is a perspective view of a metal cap in an embodiment of the metal cap caulking mounting structure of the present invention.

3 is a perspective view showing an embodiment of a metal cap caulking mounting structure of the present invention in which the metal cap of FIG. 2 is caulked and fixed to the printed circuit board of FIG.

FIG. 4 is a perspective view of a printed circuit board according to another embodiment of the metal cap caulking mounting structure of the present invention.

FIG. 5 is a perspective view of a metal cap in another embodiment of the metal cap caulking mounting structure of the present invention.

6 is a perspective view showing another embodiment of the metal cap caulking mounting structure of the present invention in which the metal cap of FIG. 5 is caulked and fixed to the printed circuit board of FIG.

FIG. 7 is a diagram showing the dimensions of the terminal legs of the metal cap of FIG.

8 is a diagram showing the dimensions of the terminal legs of the metal cap of FIG.

FIG. 9 is a diagram showing dimensions of caulking holes of the printed circuit board of FIG. 1.

FIG. 10 is a diagram showing dimensions of caulking holes of the printed circuit board of FIG. 4.

11 is a diagram showing a method of forming a caulking hole of the printed circuit board of FIG. 1.

12 is a diagram showing a method of forming a caulking hole of the printed circuit board of FIG.

13 is a diagram showing an electrical connection state between a terminal leg and a caulking hole in the metal cap caulking mounting structure of FIG. 3.

14 is a diagram showing a state of electrical connection between a terminal leg and a caulking hole in the metal cap caulking mounting structure of FIG. 6.

15 is a diagram showing a modified example of the terminal leg of FIG. 7.

16 is a diagram showing a modification of the terminal leg of FIG.

17 is a diagram showing a modification of the terminal leg of FIG. 7.

18 is a diagram showing a modification of the terminal leg of FIG.

19 is a diagram showing a modification of the terminal leg of FIG. 7.

20 is a diagram showing a modification of the terminal leg of FIG.

21A to 21C are diagrams showing an example of a conventional metal cap mounting process on a printed circuit board.

22A to 22C are diagrams showing another example of a conventional metal cap mounting process on a printed circuit board.

[Explanation of symbols]

 1 printed circuit board 2 metal cap 6 caulking hole 7 terminal leg 8 caulking hole 9a, 9b a pair of terminal legs

Claims (3)

[Claims] 1. A printed circuit board of a small electronic element is provided with a partially cut caulking hole at a peripheral portion thereof, and a terminal leg having a wide tip is provided at a position corresponding to the caulking hole at a peripheral portion of a metal cap. A metal cap caulking mounting structure for a small electronic element on a printed circuit board, wherein the terminal leg is press-fitted into the caulking hole and is caulked and fixed. 2. The metal for a printed circuit board of a small electronic device according to claim 1, wherein the printed circuit board is made of an inorganic or organic material and has a circuit on one side, both sides or multiple layers. Cap caulking mounting structure. 3. The metal cap according to claim 1 or 2, wherein the metal cap is made of a bendable metal, and has an anchor effect having a surface brazed or plated for cap protection. Metal caulking mounting structure for small electronic devices on printed circuit boards.