GB2319397A

GB2319397A - A mounting structure for a printed circuit board

Info

Publication number: GB2319397A
Application number: GB9721520A
Authority: GB
Inventors: Hiroto Kinuyama
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1996-11-08
Filing date: 1997-10-13
Publication date: 1998-05-20
Anticipated expiration: 2017-10-13
Also published as: JPH10145058A; CN1087899C; CN1182347A; KR100266828B1; JP3267521B2; GB9721520D0; KR19980042181A; GB2319397B; MX9708623A

Abstract

A metal housing for a printed circuit board has on its side walls mounting structures (3) which are formed by cutting the structure out of the wall such that the structure has a narrow portion (3a) attached at one end to the wall and a wide portion (3b) attached to the other end of the narrow portion and arranged to be pushed into resilient contact with the wall when the circuit board is mounted in position. The circuit board rests on a retaining section (3c) and may engage with the narrow portion by means of a recess in the periphery of the board (see Fig.1). An aperture (3d) allows a conductive layer at the periphery of the circuit board to be soldered to the structure. Applications include TV equipment.

Description

MOUNTING STRUCTURE FOR PRINTED BOARD The present invention relates to a mounting structure for a printed board which is suited for use in an electronic apparatus such as a television tuner.

In a mounting structure for a printed board to be used in an electronic apparatus of this type, as shown in Figs. 7 to 10, a box-shaped frame 10 formed of a metal plate is provided, on side walls 11, with L-shaped mounting leaves 12 each of which is louvered inward and has a support leaf 12a and a convex section 12b.

The support leaf 12a and the convex section 12b of each mounting leaf 12 are formed, as shown in Fig. 10, by louvering along a louver line E shown in Fig. 9.

Furthermore, a printed board 15 in which a conductive layer 14 is formed on an insulating substrate 13 is provided with holes 13a at the positions opposed to the convex sections 12b.

The convex sections 12b of the mounting leaves 12 are respectively inserted through the holes 13a of the printed board 15, and the lower surface of the printed board 15 is retained by the support leaves 12a of the mounting leaves 12. After that, the convex sections 12b and the conductive layer 14 are joined by solder 16, whereby the printed board 15 is mounted to the frame 10.

Since the printed board 15 is mounted by means of the L-shaped mounting leaves 12 in the conventional printed board mounting structure, when it expands or contracts according to the temperature of the external environment, the mounting leaves 12 do not have any spring, and therefore, cracking may occur to the solder 16 which connects the printed board 15 with the frame 10.

Furthermore, the L-shaped mounting leaves 12 are cantilevered, the inductance thereof increases, which lowers the performance.

Still furthermore, since only the rod-like convex sections 12b are soldered, the soldering strength is weak, and therefore, the applied solder is apt to peel off.

As a first means for solving the above problems, there is provided a mounting structure for a printed board wherein a side plate of a frame formed of a solderable metal plate is provided with a mounting section composed of a narrow section connected at one end to the side plate and a wide section formed at the end of the narrow section, a recessed section formed on a printed board is fitted on the mounting section so that the end of the wide section is brought into contact with the side plate, and a conductive layer formed on the periphery of the recessed section of the printed board is soldered onto the mounting section.

Furthermore, as a second solving means, the mounting section is provided with a louvered retaining section, and the printed board is retained by the retaining section.

Still furthermore, as a third solving means, the wide section of the mounting section is shaped like a trapezoid which has a long side at the end and a short side at a portion connected to the narrow section.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a printed board mounting structure according to an embodiment of the present invention.

Fig. 2 is an enlarged sectional view showing the principal part of the printed board mounting structure according to the embodiment.

Fig. 3 is an explanatory view showing a method of forming the printed board mounting structure according to the embodiment.

Fig. 4 is an enlarged perspective view showing the principal part of the printed board mounting structure according to the embodiment.

Fig. 5 is an explanatory view showing a method of forming a printed board mounting structure according to another embodiment of the present invention.

Fig. 6 is an enlarged perspective view showing the principal part of the printed board mounting structure according to the embodiment.

Fig. 7 is a plan view showing a conventional printed board mounting structure.

Fig. 8 is an enlarged sectional view showing the principal part of the conventional printed board mounting structure.

Fig. 9 is an explanatory view showing a method of forming the conventional printed board mounting structure.

Fig. 10 is an enlarged perspective view showing the principal part of the conventional printed board mounting structure.

A printed board mounting structure according to an embodiment of the present invention will be described with reference to Figs. 1 to 4.

A box-shaped frame 1 of a television tuner or the like which is formed of a solderable metal plate is provided, on side plates 2 thereof, with mounting sections 3 louvered and bent into a dogleg shape to project into the frame 1.

The mounting sections 3 are each composed of a narrow section 3a connected to the side plate 2 at one end, a wide section 3b located at the other end of the narrow section 3a, a retaining section 3c louvered on the narrow section 3a and a cutout section 3d.

The wide section 3b is shaped like a trapezoid, which has a long side at one end and a short side at the end portion connected to the narrow section 3a.

The louvered and bent mounting section 3 is shorter than a hole 2a formed by cutting as shown in Figs. 2 and 4.

As a result, the long end of the wide section 3b is partly opposed to the part of the side plate 2 that is not cut out.

Furthermore, the narrow section 3a, the wide section 3b, the retaining section 3c and the cutout section 3d of the mounting section 3 are formed, as shown in Fig. 4, by louvering along a louver line A for the narrow section 3a and the wide section 3b and a louver line B for the retaining section 3c shown in Fig. 3, and bending.

When the trapezoidal wide section 3b is formed, the cutout hole 2a is gradually narrowed, and the end of the wide section 3b is opposed to a part of the side plate 2 that is not cut out, by slight bending of the mounting section 3, which allows flexibility in the bending degree of the mounting section 3.

A printed board 4 comprises a planar insulating substrate 5, a conductive layer 6 formed on the insulating substrate 5 and recessed sections 7 formed at the side ends of the insulating substrate 5.

The conductive layer 6 is also provided on the peripheries of the recessed sections 7, and electric components such as a resistor or a capacitor are soldered thereon, though not illustrated herein.

Such a printed board 4 is first inserted into the frame 1 so that the recessed sections 7 thereof are respectively matched with the mounting sections 3.

Then, the mounting sections 3 are pressed toward the side plates 2 by the printed board 4, the ends of the wide sections 3b are brought into resilient contact with the respective side plates 2, and the printed board 4 is retained at the lower surface thereof by the retaining sections 3c.

After that, the printed board 4 is mounted to the frame 1 by connecting the conductive layer 5 with the mounting sections 3 by solder 8.

The solder 8 also spreads into the cutout sections 3d defined by forming the retaining sections 3c, whereby high solderability of the printed board 4 is achieved.

Moreover, even if the printed board 4 expands or contracts after soldering, the spring of the mounting sections 3 absorbs the expansion or contraction.

Figs. 5 and 6 illustrate another embodiment of the present invention. Mounting sections 3 in this embodiment are each provided with a narrow section 3a, a wide section 3b, a retaining section 3c and a cutout section 3d similarly to the foregoing embodiment, and each have the same structure as in the foregoing embodiment except in that the wide section 3b is shaped like a rectangle.

The mounting sections 3 are each formed, as shown in Fig. 6, by louvering along a louver line C for the narrow section 3a and the wide section 3b and a louver line D for the retaining section 3c shown in Fig. 5, and bending.

According to the present invention, since the wide sections of the mounting sections are brought into contact with the side plate when the printed board is mounted, the mounting sections can offer spring and thereby absorb the expansion and contraction of the printed board.

Accordingly, it is possible to provide a mounting structure which causes no cracking in the solder for connecting the printed board and the frame.

Since each mounting section is connected to the side plate at one end, and in contact with the side plate at the other end, that is, supported at both ends, it is possible to reduce the inductance thereof to almost half of that of the prior art, and to thereby obtain improved performance.

Furthermore, a cutout section is defined by forming the louvered retaining section, and solder spreads into the cutout section, which makes it possible to increase solderability and to thereby provide a mounting structure without solder peeling.

Still furthermore, since the bending of the mounting section can be made flexible by shaping the wide section of the mounting section like a trapezoid, it is possible to provide a mounting structure suitable in terms of design and manufacture.

Claims

1. A mounting structure for a printed board wherein a side plate of a frame formed of a solderable metal plate is provided with a mounting section composed of a narrow section connected at one end to said side plate and a wide section formed at the other end of said narrow section, a recessed section formed on a printed board is fitted on said mounting section so that the end of said wide section is brought into contact with said side plate, and a conductive layer formed on the periphery of said recessed section of said printed board is soldered onto said mounting section.

2. A mounting structure for a printed board according to Claim 1, wherein said mounting section is provided with a louvered retaining section, and said printed board is retained by said retaining section.

3. A mounting structure for a printed board according to Claim 1 or Claim 2, wherein said wide section of said mounting section is shaped like a trapezoid which has a long side at the end and a short side at a portion connected to said narrow section.

4. A mounting structure for a printed board substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.