JP2010153415A - Electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus, suitably used for a television tuner etc., which has high grounding effect. <P>SOLUTION: The electronic apparatus 1 is mounted on a circuit substrate, and includes: an insulating substrate 2 on which electronic components 52 are arranged to form an electric circuit; a metallic housing 20 which houses the insulating substrate and has partition plates 26, 27, 28, and 29 extending over the insulating substrate to partition off the electronic components; and leg portions 81, 83, 85, and 87 protruding from the partition plates toward the insulating substrate to be grounded and further penetrating the housing 40 to be grounded to the circuit substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic apparatus suitable for use in a television tuner or the like.

This type of electronic device has an insulating substrate on which a wiring pattern is formed, and various electronic components are arranged on this pattern to form a desired electric circuit.
In addition, a metal antenna terminal and a ground terminal are attached to the insulating substrate, and when the electronic device is mounted on the mother substrate, each of the rod-shaped terminals electrically connects the insulating substrate and the mother substrate (for example, Patent Document 1).

  Specifically, a plurality of ground patterns are provided at predetermined positions on the insulating substrate in order to stabilize various performances required for the electric circuit. In the vertical electronic device described in Patent Document 1, the ground pattern of the insulating substrate placed vertically is collected on the ground terminal, and the ground pattern of the insulating substrate is connected to the mother substrate via the ground terminal. Electrically connected to the ground pattern.

JP 2007-128963 A

By the way, in addition to the vertical type described above, a plurality of ground patterns are also provided on the insulating substrate in the case of a down-type electronic device. In this down-type type, the ground pattern of the insulating substrate is a metal frame. Via, it is grounded to the ground pattern of the mother board.
Specifically, the frame has a side surface surrounding the insulating substrate and a shield plate extending on the insulating substrate. A plurality of ground frame inner legs protrude from the shield plate and are grounded to each ground pattern of the insulating substrate.

Furthermore, a frame outer leg for ground projecting toward the mother board is also formed on the side surface of the frame. The ground pattern of the insulating substrate is grounded to the ground pattern of the mother substrate via the frame inner leg, the shield plate, the side surface, and the frame outer leg.
However, when grounding via this frame, there is a problem that the grounding effect cannot be enhanced.

In other words, the grounding pattern of the insulating substrate is determined in advance at the position where the stabilization of performance is ensured, and the grounding pattern of the insulating substrate and the grounding pattern of the mother substrate are always separated even when viewed in a linear distance. is there.
Accordingly, an object of the present invention is to solve the above problems and provide an electronic device having a high grounding effect.

  A first invention for achieving the above object is an electronic device mounted on a circuit board, the electronic device containing an insulating substrate on which an electronic circuit is formed by arranging electronic components, and the insulating substrate. In addition, a metal housing having a partition plate that extends over the insulating substrate and partitions the electronic component, and projects from the partition plate toward the insulating substrate and is grounded to the insulating substrate, and further penetrates the housing. And a leg portion that is grounded to the circuit board.

According to the first invention, the electronic component is arranged on the insulating substrate, and a desired electric circuit is formed. This insulating substrate is housed in a metal housing, and this housing has a partition plate and extends over the insulating substrate to partition electronic components.
Here, the partition plate is formed with legs protruding toward the insulating substrate. The leg is grounded to the insulating substrate, and further, the tip of the leg extends toward the circuit board, penetrates the housing, and is grounded to the circuit board.

  In this way, the legs that are grounded to the insulating substrate are extended to the outside of the housing, and are directly grounded to the circuit board, so that the ground pattern of the insulating substrate and the ground pattern of the circuit board are compared to the conventional case. The distance is shortened and the grounding effect can be enhanced. As a result, it contributes to improvement of various performances required for electronic devices.

According to a second aspect of the present invention, in the configuration of the first aspect, the housing includes a frame body that surrounds the insulating substrate on a plurality of side surfaces, and the frame body is composed of one metal plate, and the side surface, the partition plate, The leg is integrally formed.
According to the second invention, in addition to the action of the first invention, the frame body is configured to be assembled from a single metal plate, and as described above, the length of the leg portion is increased. However, it can be easily formed from the same parts by bending or twisting, for example. Therefore, the grounding effect is enhanced while reducing the number of parts and the assembly work time as compared with the case of using leg parts which are parts different from the frame.

According to a third invention, in the configuration of the first or second invention, the housing includes a cover that covers the partition plate, and the cover is configured to be able to stand toward the circuit board in the vicinity of the leg portion. It has the cut-and-raised part grounded to the board | substrate.
According to the third invention, in addition to the effects of the first and second inventions, the leg portion is directly grounded to the circuit board as described above, and the cover is also connected to the circuit via the cut-and-raised portion. Since it is directly grounded to the substrate, the grounding effect of the entire electronic device is enhanced, making it difficult to receive jamming radio waves, and heat dissipation of this electronic device is also improved.

According to a fourth invention, in the configuration of the first to third inventions, the electric circuit processes a high-frequency signal.
According to the fourth invention, in addition to the operations of the first to third inventions, according to the configuration in which the distance between the ground pattern of the insulating substrate and the ground pattern of the circuit board is shortened as in the above-described leg portion. Since high-frequency energy is less likely to be radiated into the air, it has a particularly remarkable effect.

  According to the present invention, the legs that are grounded to the insulating substrate are extended to the outside of the housing and directly grounded to the circuit board, and an electronic device having a high grounding effect can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view of a high-frequency unit such as an electronic apparatus according to this embodiment, for example, a television tuner. The tuner 1 is formed in a substantially rectangular parallelepiped shape in a completed state, and a surface having the largest area of the tuner 1 is configured as a face-down type facing a mother board (circuit board).

Specifically, as shown in the figure, the insulating substrate 2 disposed inside the tuner 1 has a wide bottom surface 4 and a top surface 6 that are substantially rectangular in plan view.
Four narrow side surfaces 8 and 10 are formed on the periphery of the lower surface 4 and the upper surface 6, the side surface 8 and the side surface 10 intersect, and the side surfaces 8 and 8 face each other.

  Predetermined wiring patterns 12 made of copper foil or the like are provided at appropriate positions on the lower surface 4 and the upper surface 6 (FIG. 2), and are connected through a through hole or the like. An electronic component 52 such as a coil or a capacitor is mounted on the pattern 12 on the upper surface 6, and an electronic component 50 such as an IC chip is mounted on the pattern 12 on the lower surface 4, thereby forming a desired electric circuit for processing high-frequency signals. ing.

  Further, the ground pattern 14 is also provided with a copper foil or the like on the lower surface 4 of this embodiment (FIGS. 2 and 3), and is connected to the electric circuit. The pattern 14 of the present embodiment is provided, for example, at four positions at a position that ensures stabilization of various performances required for this electric circuit. In FIG. 3, illustration of the electronic components 50 and 52 and the connector 21 described later is omitted.

  Returning to FIG. 1 again, in the vicinity of the side surface 8, for example, a total of ten metal antenna terminals 60 are arranged with a predetermined interval. Each terminal 60 of the present embodiment is a square pin whose cross section is formed in a substantially square shape and extends along the vertical direction with respect to the upper surface 6 and the lower surface 4 (FIG. 2), and is viewed with the tuner 1 in a completed state. It penetrates the upper surface 6 and the lower surface 4.

The outer peripheral surface of each terminal 60 is fixed to the wiring pattern 12 with cream solder 92, and each terminal 60 is electrically connected to the pattern 12. On the other hand, each terminal 60 protrudes downward from a metal lower cover (housing) 40, and its tip 64 is electrically connected to the mother board.
More specifically, first, the insulating substrate 2 is housed in a metal frame (housing) 20.

The frame 20 has a substantially rectangular cylindrical shape in plan view, and the peripheral wall 22 and the peripheral wall 24 of the four peripheral walls (side surfaces) 22 and 24 intersect, and the peripheral walls 22 and 22 face each other. The inner sides of 22 and 24 abut against the side surfaces 8 and 10 of the substrate 2 to surround the substrate 2.
Further, a connector 21 is provided at an appropriate position on the left peripheral wall 24 as viewed in FIG. The television signal is input to the electric circuit via the connector 21, and an output signal optimum for the signal processing is output via the terminal 60. Further, a frame outer leg 25 is formed at the lower ends of the opposed peripheral walls 24, 24 and is grounded to the mother board as will be described later.

  On the other hand, the frame body 20 of the present embodiment extends along the formation direction of the peripheral wall 24 on the inner side thereof, along shield plate (partition plates) 26 and 28 that connect the peripheral walls 22 and 22, and the formation direction of the peripheral wall 22. It has a shield plate (partition plate) 27 that extends and connects the shield plate 26 and the peripheral wall 24, and a shield plate (partition plate) 29 that connects the shield plate 28 and the peripheral wall 24, and is disposed on the upper surface 6. Each electronic component 52 is partitioned.

These shield plates 26, 27, 28, and 29 are arranged so as to pass above the respective ground patterns 14.
An upper cover (housing) 30 is placed on the upper end portions of the shield plates 26 to 29 and the upper opening portions formed by the peripheral walls 22 and 24. The upper cover 30 is a substantially rectangular lid in plan view, and of the engaging portions 32, 34 extending downward from the peripheral edge of the main body 31, the engaging portion 32 is located outside the peripheral wall 22. Reference numerals 34 respectively engage with the outside of the peripheral wall 24 and cover the upper surface 6 of the substrate 2.

On the other hand, the lower end portions of the shield plates 26 to 29 are placed on the upper surface 6, and the lower cover 40 is placed in the lower opening portion formed by the peripheral walls 22 and 24.
The lower cover 40 is also a substantially rectangular lid in plan view, and the engaging portions 42 and 44 extend upward from the peripheral edge of the main body 41. In addition, among the engaging portions 42 and 42 facing each other on the near side and the far side in FIG. 1, a total of 10 extraction holes 45 equal to the number of terminals 60 are formed in the vicinity of the engaging portion 42 on the near side. It is installed.

Then, the engaging portion 42 is engaged with the outer side of the peripheral wall 22 and the engaging portion 44 is engaged with the outer side of the peripheral wall 24, whereby the lower surface 4 of the substrate 2 is covered with the lower cover 40. The tip 64 protrudes downward from the extraction hole 45.
By the way, in the present embodiment, the shield plates 26 to 29 described above also protrude downward from the lower cover 40.

Specifically, the insulating substrate 2 is provided with four holes 56, 57, 58, 59 penetrating the upper surface 6 and the ground pattern 14 on the lower surface 4 (FIGS. 1 to 3). Holes 46, 47, 48 and 49 are also formed in the cover 40 at positions facing these holes 56 to 59.
On the other hand, frame inner legs (leg portions) 81, 83, 85, and 87 are formed at the lower end portions of the shield plates 26 to 29 at positions facing the holes 56 to 59 of the substrate 2.

  More specifically, first, as shown in FIGS. 1 and 3, a frame inner leg 81 is formed on the shield plate 26 so as to protrude from the lower end surface toward the insulating substrate 2. The outer peripheral surface is fixed to the ground pattern 14 with cream solder 94 and the frame inner leg 81 is electrically connected to the pattern 14.

Further, the end portion 82 of the inner frame leg 81 is pulled out from the hole 46 of the lower cover 40 (FIGS. 1 and 3), and is exposed to the outside.
The shield plate 27 is also formed with a frame inner leg 83 projecting from the lower end surface toward the substrate 2. The frame inner leg 83 is fitted into the hole 57 and extends toward the lower cover 40, the outer peripheral surface thereof is fixed to the ground pattern 14 with cream solder 94, and the tip end portion 84 extends from the hole 47 of the lower cover 40. Has been pulled out.

As for the shield plate 28, a frame inner leg 85 protruding toward the substrate 2 is formed, the frame inner leg 85 is fitted into the hole 58, and its outer peripheral surface is fixed to the ground pattern 14 with cream solder 94. Further, the tip 86 is drawn out from the hole 48 (FIGS. 1 and 3).
The shield plate 29 is formed with frame inner legs 87 (FIGS. 1 and 2). The inner leg 87 of the frame is fitted into the hole 59, the outer peripheral surface thereof is fixed to the ground pattern 14 with cream solder 94, and the tip end portion 88 is drawn out from the hole 49.

  Further, as shown in FIG. 4, the front ends 82, 84, 86, 88 of the frame inner legs 81, 83, 85, 87 and the frame outer legs 25 positioned below the lower cover 40 are mother boards 70. The outer peripheral surface is fixed to the ground pattern 74 with cream solder 96, and the frame inner legs 81, 83, 85, 87 and the frame outer legs 25 are electrically connected to the pattern 74.

  As a result, each of the four ground patterns 14 connected to the electric circuit can be grounded to the ground pattern 74 of the mother board 70 via the shield plates 26, 27, 28, 29, the peripheral walls 22, 24 and the frame outer legs 25. In addition, the frame inner legs 81, 83, 85, 87 are directly grounded to the ground pattern 74 of the mother board 70.

  The tuner 1 described above first prepares the insulating substrate 2 having the holes 56 to 59 and applies the cream solder 94 to the ground pattern 14. Further, the cream solder 92 is also applied to the wiring pattern 12, and the terminals 60 and the electronic components 50 and 52 are arranged on the pattern 12. The electronic components 50 and 52 may be surface-mounted on the pattern 12 on the upper surface 6 or the lower surface 4 using solder balls.

  Here, the frame 20 of the present embodiment is cut out from a single metal plate. For example, the peripheral wall 24 and the shield plate 26 are respectively communicated with the left and right ends of the shield plate 27 as shown in FIG. Peripheral walls 22 and 22 are communicated with the front and rear ends of 26, respectively. Further, both the front and back ends of the shield plate 28 are communicated with these peripheral walls 22, and the shield plate 28 and the other peripheral wall 24 are communicated with both left and right ends of the shield plate 29.

  More specifically, these communicating portions are set to widths that can be bent and twisted, and these communicating portions are arranged on the outer peripheral frame 25 and the inner frame legs 81, 83, 85, 87 of the peripheral wall 24 and the shield plates 26-29. If it is provided on the side opposite to the side having the shape and is drawn on a single metal plate, cut out along the drawn line, and each communicating portion is bent or twisted in a predetermined direction, the peripheral walls 22 and 24, the shield plate 26 , 27, 28, 29, frame inner legs 81, 83, 85, 87, and frame outer legs 25 are integrally formed.

Next, as shown in FIG. 1, the frame body 20 is lowered from above the substrate 2, and the frame inner legs 81, 83, 85, and 87 are inserted into the holes 56 to 59, respectively.
Thereafter, the electronic components 50 and 52 and the terminals 60 and the wiring pattern 12 are soldered to the inner legs 81, 83, 85 and 87 and the ground pattern 14 in a reflow furnace (not shown).

  Subsequently, the upper cover 30 is lowered from above the frame body 20, and the upper surface 6 of the substrate 2 is covered with the upper cover 30. Further, the lower cover 40 is lifted from the lower side of the frame body 20, the tip 64 of the terminal 60 is taken out from the hole 45, and the tips 82, 84, 86, 88 of the frame inner legs 81, 83, 85, 87 from the holes 46-49. When each is pulled out and the lower surface 4 of the substrate 2 is covered with the lower cover 40, the tuner 1 can shield the electronic components 50 and 52 from the outside.

Then, if the tuner 1 is mounted on the mother board 70 and the tips 82, 84, 86, 88 of the frame inner legs 81, 83, 85, 87 and the frame outer legs 25 are fixed to the ground pattern 74 with solder, The ground pattern 14 of the collected substrate 2 is grounded to the mother substrate 70.
By the way, the above-described cover may also be grounded to the mother board 70.

  Specifically, the lower cover 40A shown in FIG. 5 also has engaging portions 42 and 44 extending upward from the peripheral edge of the main body 41 and a takeout hole 45 for the terminal 60, as in the above embodiment. Further, tongue-shaped cut-and-raised portions 46F, 47F, 48F, and 49F are formed at positions corresponding to the holes 46 to 49 described above.

  A slit is formed around the cut-and-raised portions 46F, 47F, 48F, and 49F, and when the tip portions of the cut-and-raised portions 46F to 49F are pushed downward, the direction shown in FIG. As shown in FIG. 6 correspondingly, the cut-and-raised portions 46F to 49F stand up toward the mother board 70, and at the same time, the tips 82, 84, 86, and 88 of the frame inner legs 81, 83, 85, and 87 can be pulled out. Holes 46H, 47H, 48H, and 49H are formed, respectively.

  As a result, the cut-and-raised portions 46F to 49F can be grounded to the ground pattern 74 of the mother board 70 in a state where the cut-and-raised portions 46F to 49F are close to the tips 82, 84, 86, and 88. The lower cover 40 </ b> A that is in contact and the upper cover 30 that is also in contact with the frame body 20 through the engaging portions 32 and 34 are also grounded to the mother substrate 70.

  As described above, according to the present embodiment, the electronic components 50 and 52 are arranged on the insulating substrate 2, and an electric circuit for processing a high-frequency signal is formed. The substrate 2 is housed in a metal frame 20, which has shield plates 26, 27, 28, and 29 and extends over the substrate 2 to partition the electronic component 52.

  Here, on the shield plates 26 to 29, ground frame inner legs 81, 83, 85, 87 projecting toward the substrate 2 are formed. These frame inner legs 81, 83, 85, 87 penetrate the substrate 2 and are electrically connected to the ground pattern 14 on the lower surface 4 with solder 94 to stabilize high-frequency performance. Reference numerals 81, 83, 85, and 87 extend toward the mother board 70, penetrate the lower cover 40 (40 </ b> A) in addition to the board 2, and are electrically connected to the ground pattern 74 of the mother board 70 with solder 96. .

  In this way, the frame inner legs 81, 83, 85, 87 that are grounded to the board 2 are extended to the outside of the lower cover 40 (40A) and are directly grounded to the mother board 70. The distance between the ground pattern 14 of the board 2 and the ground pattern 74 of the mother board 70, that is, the length of the ground is shortened, and the grounding effect can be enhanced.

As a result, high-frequency energy is less likely to be radiated into the air, which contributes to improvements in various performances required for the tuner 1, specifically, antenna terminal voltage, image rejection, IF rejection, and the like.
Further, the frame body 20 is constructed so that it can be assembled from a single metal plate. As described above, even if the length of the frame inner legs 81, 83, 85, 87 is increased, the same components can be obtained by bending or twisting. Can be easily formed. Therefore, the grounding effect can be enhanced while reducing the number of parts and the assembly work time compared to the case of using a ground terminal which is a separate part from the frame 20.

  Further, as in the embodiment of FIGS. 4 and 5, the frame inner legs 81, 83, 85, 87 are directly grounded to the mother substrate 70, and the cover 30 is provided via the cut-and-raised portions 46F, 47F, 48F, 49F. , 40 are also directly grounded to the mother board 70. Compared to the case where this cover is grounded to the mother board via the frame body, the grounding effect of the tuner 1 as a whole is enhanced, and the interference radio wave is prevented. In addition, it becomes difficult to receive, and the heat radiation of the tuner 1 is also improved. Furthermore, for example, the trouble of winding an aluminum tape or the like around the entire tuner becomes unnecessary.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. For example, a part of the configurations of the above embodiments can be omitted or arbitrarily combined so as to be different from the above.
Further, the frame body 20 of the above embodiment has the outer frame legs 25 for the ground on the peripheral wall 24, but the inner frame legs 81, 83, 85, 87 for the ground are directly on the ground pattern 74 of the mother board 70. The outer frame leg 25 can be omitted if it is grounded.

  Furthermore, the electronic device of the present invention can naturally be applied to devices other than the television tuner, and in any of these cases, the grounding effect can be enhanced as described above.

It is a disassembled perspective view of the high frequency unit concerning the 1st example. It is sectional drawing of the unit seen from the II-II line | wire of FIG. It is sectional drawing of the unit seen from the III-III line of FIG. It is a figure which shows the connection state to the mother board | substrate by the unit of FIG. It is a perspective view of the lower cover in 2nd Example. It is sectional drawing of the unit using the cover of FIG.

Explanation of symbols

1 High frequency unit (electronic equipment)
2 Insulating substrate 14 Ground pattern 20 Frame (housing)
22, 24 peripheral wall (side)
26, 27, 28, 29 Shield plate (partition plate)
30, 40 Cover (housing)
40A Lower cover (housing)
46, 47, 48, 49 holes 46F, 47F, 48F, 49F Cut-and-raised parts 50, 52 Electronic components 56, 57, 58, 59 holes 70 Mother board (circuit board)
74 Grounding pattern 81, 83, 85, 87 Frame inner leg (leg)
94, 96 solder

Claims (4)

An electronic device mounted on a circuit board,
An insulating substrate on which an electronic circuit is formed by arranging electronic components;
A housing made of metal having a partition plate for accommodating the insulating substrate and extending on the insulating substrate to partition the electronic component;
An electronic apparatus comprising: a leg portion protruding from the partition plate toward the insulating substrate and grounded to the insulating substrate; and a leg portion penetrating the casing and grounded to the circuit substrate. The electronic device according to claim 1,
The housing includes a frame body that surrounds the insulating substrate at a plurality of side surfaces,
The frame is composed of a single metal plate, and the side surface, the partition plate, and the legs are integrally formed. The electronic device according to claim 1 or 2,
The housing includes a cover that covers the partition plate,
The electronic device is characterized in that the cover is configured to be able to stand toward the circuit board in the vicinity of the leg part, and has a cut-and-raised part that is grounded to the circuit board. The electronic device according to any one of claims 1 to 3,
The electronic device is characterized in that the electric circuit processes a high-frequency signal.

Images