JPH0346549Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to electronic devices such as FM tuners and AM tuners, and particularly relates to a board fixing mechanism in which a printed circuit board is fixed inside a metal frame.

[Technical background and conventional technology]

High-frequency devices such as FM tuners and AM tuners consist of a small metal frame, a printed circuit board installed inside the frame, and a cover attached to the frame as necessary. The FM tuner or AM tuner is used by being mounted on a motherboard in a main unit such as a radio or stereo.

FIG. 6 is an exploded perspective view showing an example of a conventional electronic device such as a high-frequency device of this type, and FIGS. 7 and 8 are plan views showing the assembled structure thereof.

Reference numeral 1 indicates a metal frame. This frame body 1 is bent into a U-shape and has three side plates 1a, 1b,
1c is formed. Two opposing side plates 1a
Claws 1d and 1e are integrally provided at the open end portions of 1b and 1b. These claws 1d and 1e are for attachment to a motherboard (not shown) of a main unit such as a radio or stereo.

A protrusion 1f is provided at the lower end of the central side plate 1c, and the protrusion 1f is provided with a positioning protrusion 1g that protrudes inward of the frame. Similarly, the open ends of the two opposing side plates 1a and 1b are also provided with downwardly extending protrusions 1j, on which are formed positioning protrusions 1i that protrude inward.

Further, reference numeral 2 is a printed circuit board. A plurality of terminals 3 are attached to one location on the edge of the printed circuit board 2. Further, shallow notches 2a, 2b and 2c are formed in the other three edges of the printed circuit board 2.

As shown in FIG. 7, this electronic device is assembled by inserting the printed circuit board 2 into the frame 1 and
The two opposing side plates 1a and 1b are pressed against the two edges of the printed circuit board 2. As a result, the protrusion 1f of the frame 1 fits into the notch 2c of the printed circuit board 2, and the other protrusion 1j of the frame 1 fits into the other notches 2a and 2b of the printed circuit board 2. Become. Then, the positioning protrusions 1g and 1i of the frame 1 come into contact with the lower surface of the edge of the printed circuit board 2, and the printed circuit board 2
will be positioned. Thereafter, as shown in FIG. 8, the edge of the printed circuit board 2 and the inner surface of each side plate 1a, 1b, 1c of the frame 1 are fixed with solder 4.

[Problems with conventional technology]

However, the conventional electronic device having the above configuration has the following problems.

(1) When fixing the printed circuit board 2 to the frame 1, first press the two opposing side plates 1a and 1b of the frame 1 inward to position the frame 1 and the printed circuit board 2. Both are fixed by solder 4. At this time, it is necessary to carry out the soldering work while accurately positioning the frame 1 and the printed circuit board 2, so the assembly work requires skill and is also complicated.

(2) Press the two side plates 1a and 1b of the frame 1,
Although positioning with respect to the printed circuit board 2 is performed, when pressing the side plates 1a and 1b, there is a risk that the side plates 1a and 1b may be twisted or deformed, such as being slightly curved. If the side plates 1a, 1b and the printed circuit board 2 are fixed in the deformed state, a dimensional deviation will occur in the positional relationship of the side plates 1a, 1b, 1c. Therefore, frame 1
When a cover is attached to the vertical opening shown in FIG. 6, improper attachment is likely to occur.

[Purpose of invention]

The present invention has been developed by focusing on the above-mentioned conventional problems, and it is possible to accurately position the frame and the printed circuit board with a simple operation, and to efficiently solder the frame and the printed circuit board. It is an object of the present invention to provide a printed circuit board fixing mechanism for an electronic device, which prevents deviations in the dimensions of a frame body after assembly and allows reliable attachment of a cover.

[Summary of the idea]

The substrate fixing mechanism for electronic equipment according to the present invention has the following features:
and a second and third side plate bent from both ends of the first side plate to form three sides; a metal frame fixed to the inside of the metal frame; A board is provided with a terminal protruding from a portion of the body where there is no side plate, and each of the open ends of the second and third side plates of the metal frame is bent inward of the side plate, and a terminal of the board is provided. The device is characterized in that a small protrusion that fits into the hole and a fixing claw that is attached to the motherboard together with the terminal are formed.

In this invention, the small protrusion at the tip of the fixing piece provided on the side plate of the frame is fitted into the hole in the printed circuit board to position and temporarily fix the printed circuit board.
It becomes possible to accurately position the frame and printed circuit board and move on to the soldering work. It is also possible to perform automatic soldering using a dip solder tank while the frame and printed circuit board are positioned. Furthermore, since the frame and the printed circuit board are accurately positioned, the dimensional accuracy of the completed frame is also increased.
In addition, since the mutual positioning of the fixing claws provided on the metal frame and the terminals provided on the board is performed with high precision, there is no misalignment between the fixing claws and the terminals when attaching them to the motherboard. It can be installed without causing any problems.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings of FIGS. 1 to 5.

FIG. 1 is an exploded perspective view showing the frame and printed circuit board of an electronic device according to the present invention, FIG. 3 and 4 are plan views showing the assembled structure, and FIG. 5 is a sectional view showing the state in which the electronic device according to the present invention is attached to the mother board of the main device.

This embodiment shows a small electronic device such as an AM tuner or an FM tuner. Reference numeral 11 indicates a metal frame. This frame body 11 is bent into a U-shape to form three side plates 11a, 11b, and 11c. Two opposing side plates 11a and 1
Two claws 11d and two protruding claws 11e are provided at the open end of 1b. These claws 11d and 11e are for attachment to the motherboard. Also, the side plates 11a and 1
At the end of 1b, there is a protruding piece 1 that is continuous with the claw 11e on one side.
1j is provided, and this protrusion 11j is provided with
A positioning protrusion 11i that protrudes inward is formed. A pair of protrusions 11f are also provided at the lower end of the central side plate 11c, and a positioning protrusion 1g that protrudes inward is provided on these protrusions.

Furthermore, a fixing piece 11k is integrally provided at the open ends of the side plates 11a and 11b, and is bent inward from the middle of the pair of claws 11d and 11e. A small protrusion 11 formed in an L-shape is provided at the tip of the fixing piece 11k. This small protrusion 11
is formed into a tapered shape.

Reference numeral 12 is a printed circuit board. A plurality of terminals 13 are fixed to one edge of the printed circuit board 12. Moreover, shallow notches 12a, 12b, and 12c are formed in the other three edges of the printed circuit board 12. Furthermore, two fitting holes 12d are bored inside the notches 12a and 12b.

Next, the work of fixing the frame and the printed circuit board will be explained.

Projection piece 11f provided on side plate 11c of frame body 11
is fitted into the notch 12c of the printed circuit board 12. Further, the positioning protrusion 1 provided on the protruding piece 11f
1g comes into contact with the lower surface of the edge of the printed circuit board 12. Similarly, the protrusions 11j provided on the side plates 11a and 11b are connected to the notches 12 of the printed circuit board 12.
The positioning protrusion 11i that fits into the protrusions a and 12b and is provided on the protrusion 11j comes into contact with the lower surface of the edge of the printed circuit board 12.

In the assembly procedure, as shown in FIG. 3, one edge of the printed circuit board 12 is first aligned with the side plate 11c, and then the two side plates 11a and 11b are pressed against the edge of the printed circuit board 12. At this time, the small protrusion 11 at the tip of the fixing piece 11k provided on the two opposing side plates 11a and 11b touches the printed circuit board 1.
It is fitted into the fitting hole 12d of No.2.

That is, the three edges of the printed circuit board 12 are positioned by the projections 11f and 11j of the frame 11 and the positioning projections 11g and 11i, and the two opposing side plates 11a and 11b are positioned by the small projections 11. As a result, it is accurately positioned and temporarily fixed to the printed circuit board 12 (see FIG. 2).

In this way, the frame 11 and the printed circuit board 12
With the parts temporarily fixed, the soldering process is carried out using a deep solder tank, and as shown in Fig. 4,
The inner surface of the frame 11 and the edge of the printed circuit board 12 are fixed by solder 14. It goes without saying that it is desirable in terms of work efficiency to perform this soldering work simultaneously with the soldering work of various electronic components mounted on the printed circuit board 12.

Figure 5 shows the FM assembled as described above.
The cross-sectional view shows a state in which an electronic device such as a tuner or an AM tuner is attached to a mother board 20 of a main body of a device such as a radio or a stereo.
Claws 1 provided on side plates 11a and 11b of frame 11
1d and 11e and the terminals 13 provided on the printed circuit board 12 are inserted into the through holes of the motherboard 20, and the electronic device is positioned. and,
The soldering operation is then carried out together with other electronic components on the motherboard 20, and the claws 11d, 11e and the terminals 13 are fixed to the conductor pattern on the back surface of the motherboard 20 by solder 21.

In the illustrated embodiment, the fixed piece 11k is bent along the vertical bending line in FIG. 1, but the fixed piece 11k is bent along the horizontal bending line in FIG. The fixing piece 11k may be bent so that the thickness direction of the fixing piece 11k is in the vertical direction in FIG.
A fixing piece 1 is also attached to the side plate 11c at the center of the frame 11.
1k may be provided, and the printed circuit board 12 may be fixed to the frame 11 from three directions.

[Effect of idea]

As described above, according to the present invention, the following effects can be achieved.

(1) Since the frame and the printed circuit board are positioned and temporarily fixed by the fixing pieces provided on the side plates of the frame, the soldering process can proceed in this temporarily fixed state. Therefore, the frame and the printed circuit board can be easily and accurately positioned and soldered without using a jig or the like for positioning the frame and the printed circuit board.

(2) The frame and printed circuit board are accurately positioned by fitting the small protrusions on the fixing piece into the holes in the printed circuit board, so each side plate of the completed frame has an accurate dimensional relationship with each other. It is assembled at. Therefore, even when the cover is attached to the opening of the frame, there is no possibility that the cover will be improperly attached. Furthermore, since the mutual position of the fixing claws provided on the open end of the side plate of the frame body and the terminals provided on the board can be determined with high precision, when fixing to the motherboard, the fixing claws and the terminals can be easily aligned. There is no mutual positional deviation, and the mounting on the motherboard is ensured. In particular, as in the illustrated embodiment, the fixing piece 11
By making the small protrusion 11 at the tip of k into a tapered shape and strongly pressing it into the fitting hole 12d of the printed circuit board 12 for a strong fit, each side plate and the printed circuit board can be temporarily fixed reliably and accurately. become.

(3) Since the fixing piece is simply bent and formed on the side plate of the frame, no new parts are required and the structure is simple.

[Brief explanation of drawings]

Figures 1 to 5 show an embodiment of the present invention, with Figure 1 being an exploded perspective view showing the frame and printed circuit board, and Figure 2 showing the frame and printed circuit board assembled. 3 and 4 are plan views showing the fixing structure between the frame and the printed circuit board, and 5.
The figure is a sectional view showing the state in which the electronic device according to the present invention is attached to a motherboard, FIG. 6 is an exploded perspective view showing the frame and printed circuit board of a conventional electronic device, and FIG.
This figure and FIG. 8 are plan views showing a conventional fixing structure between a frame and a printed circuit board. 11...Frame body, 11a, 11b...Opposing side plates, 11c...Central side plate, 11d, 11e...
Nails for attaching mother board, 11g, 11i... Board positioning protrusion, 11k... Fixed piece, 11... Small protrusion, 12... Printed circuit board, 12d... Hole for fitting small protrusion, 13... Terminal, 14 , 21...Solder, 20...Mother board.

Claims (1)

[Scope of utility model registration request] A metal frame body configured with three sides by a first side plate and second and third side plates bent from both ends of the first side plate; It consists of a board with terminals protruding from the part of the frame body without side plates,
The open ends of the second and third side plates of the metal frame each have a small protrusion that is bent inward of the side plate and fitted into the hole of the board, and a small protrusion that is attached to the motherboard together with the terminal. A substrate fixing mechanism for an electronic device, characterized in that a fixing claw is formed.