JPS5816207Y2 - Soldering structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a soldering structure for a board used in an electronic tuner circuit of, for example, a television receiver.

2. Description of the Related Art In general, for example, an electronic tuner circuit of a television receiver or the like is configured such that a board is disposed within a box-shaped chassis and is shielded from the outside.

This substrate is usually made of phenol resin, glass epoxy resin, etc., and a copper foil or ζ-turn is formed on the lower surface of the substrate by etching or the like using copper or the like.

In other words, Figure 1 shows the pattern, and the substrate 1
Metal plate 1 as a frame whose surroundings also serve as a chassis
It is surrounded by 2 and 1.

In the structure described above, the board is usually grounded through the metal plate 12, and the ground portion of the copper foil pattern formed on the bottom surface of the board and the metal plate 12 are connected by soldering. It was attached and grounded.

That is, FIG. 2 shows the back side of the board opening shown in FIG. 1, and the copper foil patterns 21, 22, 23, 24, 2
Grounding parts 27, 28, 29, 30, 31, 32 are provided so that 5, 26 are grounded at various places on each side of the base falcon,
It is connected to the metal plate 12 by solder.

FIG. 3 is a tsubo-sized diagram of the installation section, in which the metal plate 12 and the copper foil pattern 22 are soldered with solder 35.

However, with the above-mentioned grounding method, accidents often occur in which the solder is easily cut.

The applicant has focused on the above points, and conducted a temperature cycle test to test the reliability of the substrate, and conducted experiments to determine the degree of expansion and contraction of the substrate.

In the above experiment, the board button including the copper foil pattern and the parts placed on the potato board, the solder of the part and the upper foil pattern, the frame, and the butter, etc. It has been confirmed that the outer part of the garment is expandable.

FIG. 4 shows the pattern of expansion and contraction of the substrate, and it was confirmed that the corners 41, 42, 43, and 44 of the substrate each extended toward the outside (indicated by the arrows in the figure).

From this, it can be seen that the degree of expansion and contraction of the substrate is particularly remarkable at each corner portion 41, 42, 43, and 44 of the substrate.

Furthermore, it is clear that the degree of expansion and contraction of the substrate varies depending not only on the temperature but also on the material of the substrate.

If we consider a substrate surrounded by a frame from the above perspective, the expansion and contraction of the substrate will be particularly noticeable at its corners.

In the above case, since the material forming the substrate and the material forming the frame are different for the button, the degree of expansion and contraction of the substrate and the degree of expansion and contraction of the frame are naturally different.

As a result, different expansion and contraction forces are transmitted to the grounding portion between the copper foil pattern formed on the lower surface of the substrate and the frame, and a force for completely cutting the solder is applied.

If the above phenomenon is repeated, the solder may crack and eventually break as time passes.

As a result, the circuit formed on the board cannot operate normally because the ground cannot be connected, which becomes a major factor in reducing reliability.

This idea was made to eliminate the above-mentioned drawbacks; it does not change the electrical characteristics, and it also has a structure that connects to the frame as before, minimizing the degree of expansion and contraction of the board due to temperature rise. An object of the present invention is to provide a soldering structure that can eliminate solder breakage and improve the reliability of a circuit.

That is, FIG. 5 shows an embodiment for achieving the above object.

In the figure, I is a substrate.

Further, Σ3 is a frame made of a metal plate.

The frame 52 has a rectangular tube shape that has a larger outer circumference than the substrate 1 and surrounds the edge of the substrate 0, for example, halfway in the vertical M direction.

The degree of expansion and contraction of this substrate was tested by the applicant as described above.

As a result, the part with the least degree of expansion and contraction on the board is 53 on each side,
It was confirmed from the measurement results that it was at the center of 54°55.56.

Therefore, the soldering portions 57, 58, 59, 60 are configured such that the copper foil pattern (not shown) of the board is grounded at the center of each side 53, 54, 55, 56 of the board.

And the soldered parts 5 on each side 53, 54, 55° 56 of the board
7, 58, 59, 60 and the frame 52 are soldered.

In addition, in the above embodiment, soldering was performed at the center of each side of the board, but it is not necessarily necessary to solder all of the sides, and the soldering points may be soldered to the extent that the electrical characteristics of the circuit are not affected. can be reduced.

According to the soldering structure of this invention, since the solder is applied to the part of the board that has the least degree of expansion and contraction, the solder is not cut and the reliability of the circuit on the board can be improved.

Do soldering again? Since the race is the same as before, the electrical characteristics will not change.

Since the soldering point is placed in the center of each side of the board, there are fewer soldering points compared to the conventional method, which also improves workability.

As described above, this invention can provide a soldering structure that can improve circuit reliability and work efficiency without changing the conventional electrical characteristics.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the board shielded by the frame, Figure 2 is an explanatory diagram showing the copper foil pattern on the board and soldering of the pattern, and Figure 3 is for grounding the copper foil pattern and the frame. Fig. 4 is an explanatory drawing showing the expansion and contraction state of the board, and Fig. 5 is an explanatory drawing showing an embodiment of this invention, and shows the state in which the center of each side is soldered. figure. I... Board, 52... Frame, 53, 54° 55
．． 56...Each side of the board, 57, 58, 59°60...
・Soldering part.

Claims (1)

[Scope of utility model registration request] A board on which a grounding solder part of copper foil/<turn is set on at least one of the sides forming the peripheral part, and a copper foil/<turn solder part for grounding is set in the middle part where there is little expansion and contraction due to temperature changes, and the part is arranged along the peripheral part of this board. A metal plate having a part of its inner peripheral surface connected to the grounding soldering part, and a soldering failure that occurs due to a temperature change between the board and the metal plate when the soldering part and the metal plate are soldered. A soldering structure characterized by preventing.