JPH0528799Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a printed circuit board fixing structure for fixing a printed circuit board of an electronic device to a metal frame that also serves as a shield case.

[Prior Art] FIGS. 1 and 2 show an embodiment of the present invention, and since the structure is almost the same as the conventional example except for the claw portion, these figures and FIG. A conventional example will be explained with reference to FIGS.

When fixing the printed circuit board 1 to the metal frame 2,
A notch is made in the side surface of the metal frame 2 to form a claw 3 connected to the frame 2 at the base end, and the claw 3 is connected to the frame 2 at the base end.
A fixing structure is used in which the circuit board is bent inside the frame body 2 and the claws 2 and a circuit formed on the printed circuit board 1 are soldered. According to this, both mechanical fixing and electrical grounding can be achieved by using the above circuit as a grounding circuit.

In the above case, instead of fixing the claws 3 by simply soldering, an appropriate member fixed to the frame 2 on the opposite side of the board 1 from the claws 3 (for example, as shown in FIG. By applying a plurality of shield plates 4) assembled perpendicularly to the board 1 and holding the board 1 between them and the claws 3, the fixing is firm and the positioning is accurate, and the soldering work is made easier. It also becomes easier.

Conventionally, the structures of the above-mentioned claws shown in FIGS. 7 to 10 have been adopted. 7th
The figure shows a simple rectangular nail 3a, and FIG. 7 is formed on the claw 3b.

[Problems to be solved by the invention] However, in the above-mentioned conventional techniques, there were the following problems to be solved.

That is, these claws 3a and 3b hold the substrate 1
In order to fix the board 1, the board 1 is placed on the shield plate 4 and positioned, and then the claws 3a and 3b are bent inward. In this case, there is a method in which the bending is stopped with a gap S between the board 1 and the board 1 as shown in FIG. There is a method of soldering the circuit board 1 in close contact with the circuit surface 1a of the board 1.

However, in the former case, since the board 1 is not pressed down sufficiently during soldering, the board 1 wobbles vertically or horizontally, and as the solder shrinks, the board 1 is lifted off the shield plate 4. Otherwise, a positional shift may occur between the substrate 1 and other members. On the other hand, in the latter case, since the claws 3a and 3b are bent deeply, the claws, especially near the base end 6, elastically deform the substrate 1, causing the substrate 1 to warp or crack. Furthermore, soldering is not easy, and since the amount of solder is small, the solder joints tend to peel off due to distortion or temperature changes. Furthermore, it is difficult to automate soldering.

The object of this invention is to provide a printed circuit board fixing structure that allows easy soldering and sufficient fixing and positioning using simple means.

[Means for Solving the Problems] In order to solve the above-mentioned problems, this invention includes a metal frame that surrounds the peripheral edge of a printed circuit board at a position corresponding to the peripheral edge of the circuit board, and a base end portion communicating with the base end portion, a constriction portion and a presser portion extending upward from the base end portion, and
A first claw that can be bent inside the metal frame from the constriction part is provided, the first claw has a base end on the distal end side of the presser part, and the first claw can be bent inside the metal frame. A ground conductive circuit is formed on the printed circuit board at a position corresponding to the second claw, and each of the first and second claws is bent inside the metal frame. , a protrusion is formed by a second claw, the tip of the protrusion by the second claw is brought into contact with the ground conductive circuit, and in this state, the first and second claws and the ground conductive circuit are soldered. It is attached.

[Function] In the printed circuit board fixing structure having such a configuration, the first and second claws are bent inside the metal frame, and the second claw forms the protrusion, so that the tip of the protrusion is fixed. It comes into contact with the surface of the printed circuit board and elastically presses the board using the elastic force of the metal frame. The protrusion forms a certain gap between the tip of the claw and the printed circuit board surface, so by flowing molten solder into this gap, a sufficient amount of solder can be applied while the board is fixed and positioned. Soldering is performed using solder.

[Embodiments] Hereinafter, embodiments of this invention will be described with reference to the drawings of FIGS. 1 to 6. Note that in FIGS. 1 and 2, the parts other than the claws are the same as those of the conventional example, so the reference numerals are the same and the explanation will be omitted.

In the present invention, as shown in FIG. A constricted portion 8 is formed between the shield plate 6 and the shield plate 6 at a specific position, that is, at a position corresponding to the upper surface of the shield plate 4 when the substrate 1 is placed on the shield plate 4. It's summery. A second pawl 9 is formed on the holding portion 5 with its base end facing toward the distal end of the first pawl 3. These claws 3 and 9 are usually molded at once by punching using a metal mold to form incisions.

A method for fixing the printed circuit board 1 using the claws 3 and 9 formed by the cuts as described above will be described.

First, as shown in FIG. 2, the printed circuit board 1 is placed on the shield plate 4 and housed in the metal frame 2.
Next, while pressing the holding part 5 of the first claw 3 from the inside with a suitable jig, the tip of the second claw 9 is pushed from the outside and bent inward to form the protrusion 10. Although this bending angle is approximately 30 degrees in the figure, it may be set to any appropriate angle. Next, press the holding part 5 of the first claw 3 from the outside and push it inward as shown in FIG.
degree) to bend. At this time, the first claw 3 is locally formed with a narrow constriction 8, and this position corresponds to the upper surface of the substrate 1, so that the bending position does not vary. In addition, since the elastic force due to bending is not so large, the substrate 1
The substrate 1 is prevented from cracking or warping without applying excessive force to the substrate 1. In this state, the side and top corners of the board 1 are held down by the proximal end 6 of the first claw 3, and the circuit surface 1a is held down by the protrusion 10, thus restricting horizontal and vertical movement. be done.

In this state, as shown in FIG. 5, an automatic soldering machine 13 consisting of a heating pipe 12 containing molten solder 11 is used to apply solder 11 between the claws 3 and 9 and the circuit surface 1a of the board 1. Let it flow into the gap S,
Connect the solder 11 to the first claw 3, the second claw 9 and the circuit surface 1.
A and A are respectively fixed to form a fixing structure as shown in FIG. At this time, the solder 11 naturally flows into the gap S since the first claw 3 forms a gap S that expands outward between the first claw 3 and the circuit surface 1a.
Furthermore, since the second claw 9 protrudes into the gap S, the second claw 9 increases the adhesion area of the solder 11 and increases the fixing strength.

In this embodiment, the protrusion 10 is formed by making a notch in the joint surface of the tip of the claw 3, but other suitable methods such as press molding may be used.

[Effects of the invention] As detailed above, this invention includes a metal frame that surrounds the peripheral edge of the printed circuit board, a base end that connects to the metal frame at the bottom, and a base end that extends upward from the base end. A constriction portion and a presser portion are formed, and
A first claw that is bendable from the constriction to the inside of the metal frame is provided, and the first claw has a base end on the distal end side of the presser part and is bendable to the inside of the metal frame. A second pawl is provided and a second pawl is provided on the printed circuit board.
A ground conductive circuit is formed at a position corresponding to the claw, the first and second claws are each bent inside the metal frame, and the second claw forms a protrusion,
The tip of the protrusion formed by the second claw is brought into contact with the ground conductive circuit, and in this state, the first and second claws and the ground conductive circuit are soldered. When the claw is bent, the tip of the protruding part of the second claw comes into contact with the board and presses the board with a moderate elastic force, so the board does not move during soldering and does not distort or crack the board. The occurrence of is suppressed. Further, since an appropriate gap is formed by the protrusion, the soldering work is facilitated, and a sufficient amount of solder is ensured, and the area to which the solder is attached is increased, so that the fixing strength is increased.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an embodiment of this invention, Fig. 2 is an inverted perspective view of Fig. 1, Fig. 3 is an enlarged view of the main parts of the embodiment, and Figs. 4 to 6 are its fixing. A diagram showing the process, FIGS. 7 and 8 are diagrams showing a conventional example,
FIGS. 9 and 10 are diagrams showing the fixing process. 1... Printed circuit board, 2... Frame, 3... First
claw, 5... presser plate, 6... base end, 8... constriction, 9... second claw, 10... protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] A metal frame surrounding the periphery of the printed circuit board has a base end that connects to the metal frame at the bottom and a base end extending upward from the base end at a position corresponding to the periphery of the board. A constriction part and a presser part were once formed, and a first claw that can be bent from the constriction part to the inside of the metal frame is provided, and the first claw has a proximal end on the distal end side of the presser part. a bendable second claw is provided inside the metal frame; a ground conductive circuit is formed on the printed circuit board at a position corresponding to the second claw; Each of the second claws is bent inside the metal frame, a protrusion is formed by the second claw, and the tip of the protrusion formed by the second claw is brought into contact with the ground conductive circuit. A fixed structure for a printed circuit board, characterized in that first and second claws and a ground conductive circuit are soldered.