KR850000504Y1 - Shield device - Google Patents

Abstract

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Description

Sealed device

1 is a schematic exploded perspective view showing a shield device according to the present invention.

FIG. 2 is a side view showing a shield body constituting the apparatus shown in FIG.

3 is a front view showing a state in which the device shown in FIG. 1 is assembled.

Figure 4 is a side view showing in some cross-sectional view for explaining when soldering each shield device according to the present invention.

FIG. 5 is a side view showing in partial cross section illustrating a separate configuration when soldering the same. FIG.

Figure 6 is a perspective view showing a part after the brazing of the shield device according to the present invention.

7 is a schematic partial side cross-sectional view showing a state in which a cover is covered in the shield device according to the present invention.

The present invention relates to a shield device applicable to a tuner device used for a television receiver or the like.

Electronic tune-in TV tuners using voltage-controlled variable-capacitance diodes currently used in television receivers are framed and placed on one spherical side of a metal chassis composed of a viewing shield plate that seals the interior into a predetermined compartment. A printed wiring board having a pattern formed thereon is mounted, and various electrical components are soldered to form a predetermined circuit on the printed wiring board, and the electrical components are arranged in respective compartments.

On the other side of the printed wiring board, that is, on one side of the circuit pattern side, a shield plate constituting the bush shield plate electrically and mechanically maintained with the chassis is disposed and used for VHF and UHF arranged on the printed wiring board. This prevents unnecessary coupling between the circuits of the oscillation circuit, the input circuit, or the mixed circuit. Both openings of the metal chassis are covered with metal covers so as to seal these circuits and the whole parts, and the shielding effect is maintained. In such a tuner, after inserting an electrical component required for a printed wiring board, the substrate is placed in a chassis, and then passed through an automatic soldering tank of a sorting or dip type, whereby the electrical component and the circuit pattern of the printed wiring board are connected. Soldering and soldering of chassis and printed wiring boards are carried out, and then the shielding plates are manually soldered.

BACKGROUND ART In recent years, so-called chip components, which are formed by miniaturizing semiconductor components such as transistors and diodes, and general components such as resistors, capacitors, and inductors, have tended to be used for the electrical components attached to the printed wiring board. Since the chip parts are mounted on the opposite side to the generally arranged electrical parts of the printed wiring board, that is, on the circuit pattern side, in order to seal the circuit as in the prior art, the chip parts may also be mounted on the circuit pattern side of the board on which the chip parts and the like are mounted. It became necessary.

However, since the mounting of the shield plate is performed by hand after soldering of the substrate, the electric component and the chassis as described above, the workability is not good and the number of the workers is required as well. In addition, since the printed wiring board is heated twice, the circuit pattern part made of copper foil (thin copper) is peeled off from the substrate surface, deterioration in the reliability of soldering due to disconnection or uneven soldering amount by hand, or chip component. There were problems such as damage due to cracks due to heating.

In addition, there is an extremely high risk that the plate may bend and deform due to the heating of the printed wiring board itself, resulting in an imbalance in performance, adhesion, poor soldering, or cutting of a copper foil pattern. In addition, it is not good in handling and workability, such as deterioration of assembly work or dirty hands due to the change of the substrate size in order to perform the soldering work by hand after the automatic soldering is finished. This is a problem when attaching the shield plate, but even after the shield plate is attached, it is necessary to make earth connection between the chassis and the cover or the cover and the shield plate. Since the contact pressure is unbalanced due to the imbalance of the precision of the position of the seal, a material that exhibits stable characteristics even in a low contact pressure state such as a temperature gold is used for the shield plate, and these defects have various disadvantages such as being more expensive.

The present invention has been studied in view of this point, and relates to an improvement of a shield device that is simple in configuration and can achieve a reliable configuration. Hereinafter, a shield device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic structure of the whole of the present invention when the present invention is applied to an electronic tuner used in a television receiver. That is, it consists of the chassis 11 formed in the metal frame shape, the printed wiring board 12, and the shield body 13. As shown in FIG. The chassis 11 uses, for example, a metal plate having a lead as a main component on a surface of an iron plate, and a coating material coated with tin or the like applied thereto. The metal plate is generally referred to as a tertiary sheet.

This metal plate is cut and bent into a predetermined shape to form a frame chassis 11 as shown in the figure. The chassis 11 will be described again, and the chassis 11 has respective side plates 14a, 14b, 14c, and 14D, which are framed by the respective side plates 14a and 14d. It consists of a quadrilateral as a whole. And the partition plate 17 which divides the UHF tuner part 15 and the VHF tuner part 16 is integrally formed, and this partition plate 17 is integrally formed, and this partition plate 17 and An input part, an amplifier part, a local oscillation circuit part, and a mixer part are respectively disposed between the side plates 14c, and partition walls 18a-18c are integrally disposed so as to partition the inside of the UHF tuner part 15 again.

These side plates 14, partition plates 17, and partition walls 18 are arranged so that their plate surfaces are in the same direction as both opening directions of the frame of the chassis 11. In addition, in the partition board 17, projections 20 each fitted with a plurality of insertion holes 19 formed in the printed wiring board 12 protrude from the cross section of the partition board 17, and are partitioned in the same manner. The projection 21 also protrudes from the wall 18.

Then, the protrusion pieces 22 are formed inward from the plate surfaces of the side plates 14a, 14b, and 16d, and the protrusion pieces 22 are configured to be in contact with the plate surfaces of the printed wiring board 12. In addition, a plurality of planar pieces 22 are formed on each side plate 14 so as to be perpendicular to the plate surface of the side plate 14, but the pieces 22 are configured to be in contact with a cover (not shown).

The chassis 11 is provided with an insertion hole, a cutout, or the like for arranging a terminal for external lead-out, but is omitted because it is not directly related to the present invention. Referring to the printed wiring board 12 disposed in the chassis 11 formed as described above, the printed wiring board 12 has a predetermined circuit pattern 30 formed of copper foil on one side thereof, and the insertion hole as described above. Also, a predetermined number (19) is disposed at positions corresponding to the protrusions (20) and (21), respectively. Since the illustrated printed wiring board 12 is only an outline, detailed circuit pattern diagrams, component insertion holes, and the like are omitted, and in practice, various electrical components are discharged on the printed wiring board 12. For the sake of brevity.

The printed wiring board 12 is inserted into the chassis 11 from the noncircuit pattern side in the same direction as the arrow. The projections 20 and 21 are inserted into the insertion holes 19 of the printed wiring board 12, and the plate surface abuts on the protrusion pieces 22, so that the protrusions 22 and the plate surface come into contact with the protrusions 20. And the printed wiring board 12 is positioned at a predetermined position by contact with the end of 21, or the like.

The shield body 13 is held on the surface side of the circuit pattern 30 of the printed wiring board 12 again. As shown in FIG. 2, the seal body 13 has a structure in which narrow and long thin plates (thin plates) are connected as a whole.

Referring to the illustration, the four shield plates 41-44 in which the plate surface is discharged at right angles to the plate surface of the printed wiring board 12 are arranged so as to be in the same direction, and the inner two shield plates 42 and ( The shield plate 43 is shortly formed so that one end of the shield plates 41 and 44 on both sides thereof stops in the middle, and the shield plates are configured such that the plate surface is located in the orthogonal direction with the printed wiring board 12 between the ends thereof. 45).

Then, between the shield plates 41, 42, 43, and 44, the plate surfaces are arranged in a direction orthogonal to the plate surfaces of these shield plates 41-44, that is, the printed wiring board 12. The plate surface is connected by the connecting plate 46 in which the plate surface is arrange | positioned in such a relationship parallel to the plate surface of the.

These connecting plates 46 are located in the middle of the plate width of the shield plates 41-44. The shield plates 41-45 are formed in a plate shape, but the ones which are not necessary are cut out to form a space portion, and an attaching portion 47 for attaching on the printed wiring board 12 surface is provided with a shield plate 41. From -45).

The attachment leg portion 47 is configured such that an end portion 48 is formed and tapered at the tip, and the thin tip is inserted into a predetermined corresponding insertion hole 19 of the printed wiring board 12, and the printed wiring board is provided. The tip of the attachment leg 47 penetrating (12) is bent on the other side of the printed wiring board 12, twisted and fixed, so that the shield body 13 can be temporarily fixed on the printed wiring board 12. have.

For the end portion 48 of the attachment leg portion 47, the shield plates 42, 43, and 45 float on the circuit pattern 30 surface of the printed wiring board 12 to be in a non-contact state. However, since the attachment leg portion 47 is configured to be in contact with the earth (grounding) pattern portion of the printed wiring board 12, the shield body 13 becomes an earth voltage. And the earth pattern of the printed wiring board 12 on the shield plates 41-45, respectively, to ensure this earth potential or for the earth potential point circuit portion on the circuit pattern 30 of the printed wiring board 12. The connecting leg portion 49 in contact with the portion is appropriately installed.

The connecting leg 49 not only maintains the shield plate 13 at an earth potential but also prints the same length as the length from the shield plates 41-45 to the end 48 of the attaching leg 47. It also serves as an earth circuit for the wiring board 12. That is, the shield body 13 is provided by attaching the attachment leg portion 47 or the connection leg portion 49 to a portion of the circuit pattern of the printed wiring board 12 that requires an earth potential point, particularly near the center portion of the printed circuit board. Since it is possible to set the earth potential through the circuit, it is not necessary to form the shape on the pattern of the printed wiring board 12, and even if it is formed in an island-like pattern separated from the other, the circuit which easily forms an earth potential by forming and arranging as mentioned above is formed. I can assemble it. In the shield plates 41 and 44, the shield plates 41 and 44 themselves can be brought into contact with the earth pattern portion of the printed wiring board 12 to be soldered.

As a matter of course, the attachment leg portion and the connection leg portion may be provided. Alternatively, the plate body itself may be directly processed as in the case of the shield plates 41 and 44 by processing the shield plates 42, 43, and 45 itself. It is clear that you may solder with an earth pattern.

When it is necessary to take the earth more reliably, the solder joints can be made to have a large area when the click pieces 50 are soldered by the shield plates 41, 44, and the like.

These shield sieves 13 have a plane at a position approximately equal to the plate cross-sectional position in a direction orthogonal to the plate body on a cross section side opposite to the cross section on which the attachment leg portion 47 or the connecting leg portion 49 is provided. The bending piece 51 is installed.

Thus, the shield body 13 is formed, and this shield body 13 is attached to the circuit pattern side of the printed wiring board 12 in the arrow direction shown in FIG.

The front view of the tuner thus formed is shown in FIG. Also in FIG. 3, various electric parts, circuit pattern diagrams, etc. mounted on the printed wiring board 12 are abbreviate | omitted.

Thus, the method of integrally soldering and fixing the chassis 11, the printed wiring board 12 and the shield body 13 will be described with reference to FIG.

In FIG. 4, the chassis 11, the printed wiring board 12, and the shield body 13 are assembled in combination as described above. The assembly is placed so that the circuit pattern side of the printed wiring board 12 is positioned downward between the pallets 60 of the automatic soldering apparatus. The pallet 60 applies the flux (solvent) as it moves by driving on a conveyor track, and submerses in a dip type or automatic type soldering tank.

As a result, the chassis 11, the shield body 13, and the printed wiring board 12 were soldered, respectively, and the capacitor was temporarily fixed in advance with an adhesive or the like at a predetermined position on the circuit pattern side of the printed wiring board 12. The terminals of the electric component 62 disposed on the non-circuit pattern surface side of the chip component 61 and the printed wiring board 12 such as resistors and projecting through the terminal on the circuit pattern surface side are respectively prescribed by the printed wiring board 12. It is soldered together with the circuit pattern copper foil of.

Therefore, the connection between the three characters of the chassis 11, the printed wiring board 12, and the shield body 13, and the various electrical components 61, 62, and the circuit pattern of the printed wiring board 12 are collectively. Is done. At this time, since the printed wiring board 12 is sandwiched by the partition board 17, the partition wall 18, etc. of the chassis 11, and the shield body 13, the bending by the heating at the time of soldering is prevented more reliably.

In addition, although the three members of the chassis 11, the printed wiring board 12, and the shield body 13 are mutually connected at the time of this soldering, in the structure which makes this soldering connection, it is not limited to this example, Various modifications, Application is possible, for example, as shown in FIG. 5, the shape of the chassis 11 is formed to be smaller than the size of the printed wiring board 12, so that the printed wiring board 12 is not surrounded by the chassis 11 It is to be noted that the shield body 13 and the circuit pattern portion of the printed wiring board 12 may be soldered to each other at the peripheral portion thereof, and the chassis 11 and the printed wiring board 12 may be soldered, respectively, to integrate the whole. Nothing.

Of course, the shield body 13 is not soldered only at the periphery of the printed wiring board 12, but at the intermediate position of the printed wiring board 12 due to the presence of the attachment leg portion 47 or the connecting leg portion 49. It is obvious that even soldering. At the time of soldering, each bending piece 51 of the shield body 13 is formed with a deposition portion 70 of solder having a thickness of about 100 to 500 µ on the plane of the bending piece 51 as shown in FIG. .

This solder deposit portion 70 has a relatively large area because the chassis 11 and the shield body 13 are formed as round sheets as described above, and the solder portion is well buried in the flat portion where the coating portion is present. In addition, the surface cut by a press or the like, such as the cross section of the chassis 11, hardly adheres solder because the coating portion is removed and the bottom plate portion of the plate is exposed to the outside.

For this reason, the solder | pewter adheres well to the bending piece 51 and the connection board 46. FIG. However, since the connecting plate 46 is located in the middle of the shield body 13 which is struck below the surface of the bent piece 51, even if solder is attached, the tip of the solder is the shield body end 13 surface. It does not protrude from and does not adversely affect anything.

If the width of the connecting plate 46 is narrowed, the amount of lead adhesion decreases, so that it can be formed linearly if necessary. Therefore, as described above, the bent piece 51 is located on substantially the same plane as the cross sections of the shield plates 42, 43, and 45, so that the deposition portion 70 of the solder is the shield plate 42. The tip protrudes to the position which protrudes outward from the cross section of (43) and (45).

The solder deposit portion 70 has a softer surface strength than the material of the chassis 11 or the shield body 13 because of the solder. This solder deposit portion 70 can be used as a contact portion with the lid 75 as shown in FIG.

That is, the elastic piece 76 protruding inwardly is formed by standing up and formed in the place corresponding to the said solder deposit part 70 of the cover 75 which covers the opening part of the chassis 11, and this elastic piece 76 and The solder deposits 70 are elastically pressed.

As a result, by maintaining the strength of the elastic piece 76 relatively large, the solder deposition portion 70 deforms into a contact shape with the elastic piece 76 to match with the elastic piece 76, thus providing a larger area. Since the solder deposit portion 70 and the elastic piece 76 are in contact with each other, the electrical connection as well as the mechanically stable positional relationship can be maintained. The lid 75 is elastically fitted and held by the binding piece 77 composed of a plurality of protrusions arranged around the lid 75 with respect to the chassis 11. The other opening portion of the chassis 11 is also covered by the lid 75 in a similar manner, and the elastic piece 76 elastically with the protrusion piece 22 provided on the partition plate 17 or the like installed on the chassis 11. Configured to contact. Therefore, the circuit disposed in the chassis 11 is entirely sealed by the chassis 11 and the lid 75 and constitutes a tuner.

As described above, according to the present invention, since the shield body is soldered at the same time when soldering the printed circuit board and the components to the printed circuit board at the same time, only the shield body can be soldered manually by hand later, and the work man-hour is reduced. There is no heating on the substrate twice, and the deterioration of components, the peeling or cutting of the copper foil pattern, etc. are prevented.

In addition, since the shield body is attached at the same time when soldered to the printed wiring board, the phenomenon in which the substrate is warped can also be suppressed, and the adverse effect due to the warpage of the substrate can also be prevented.

In addition, if the three characters of the shield body, chassis and printed wiring board are soldered at the same time, the three characters will be automatically soldered to each other for better work improvement. As a result, the warpage of the board is further prevented, so that not only a uniform product can be obtained. In addition, when assembling these parts, the flux (solvent) for soldering is still applied, so it is easy to assemble and reduce the phenomenon of dirt. There is this.

In addition, when the shield body is used as part of the earth circuit, problems such as unevenness of the earth potential due to thin copper foil of the printed wiring board are also eliminated, and reduction of the ground portion of the circuit pattern provided on the printed wiring board is also eliminated. It is possible to improve the space factor of the substrate, the degree of freedom in circuit pattern design, the circuit impedance, or the circuit board strength.

In addition, if the solder deposit is used to contact the elastic piece of the cover, the hardness of the solder is soft, so that the elastic force is strengthened. I can improve it more. This is more effective in the high pressure part and smaller in the low pressure part so as to reduce the pressure fluctuation due to the dimensional error or the deformation of the elastic piece when a large number of contact points are required in the shielding body. There is an advantage that you do not have to.

In addition, even if it is automatically soldered in the state of attaching a shield body using a metal plate coated with a material that can be easily soldered as a shield sieve or a chassis material, the cross section other than the bent portion is exposed to the outside, so lead is hard to be buried. Even after the soldering is finished, the amount of lead attached to these cross sections is extremely small, and it is possible to finish it with a minimum amount of lead attached without any trouble, and to exert a large amount of lead only where necessary.

In addition, this invention is not limited to what was described in these description and drawings, Although various application and a modification are considered, such a case is also included in the scope of this invention.

Claims (1)

A printed wiring board 12 having a predetermined circuit pattern formed thereon, and a plane which is located on the circuit pattern side of the printed wiring board and is substantially orthogonal to the substrate surface so as to partition the circuit pattern, wherein the solder adhesive nose And a shielding body 13 comprising a plurality of shielding plates 41 to 45 which have been coated, and a bending piece 51 formed by bending substantially at right angles to the planar portion of the shielding plate. 12) A shielding device, wherein the shield body (13) is soldered.