JP2006049466A - Mounting structure of electronic parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of electronic parts capable of securing electric conductivity and good heat dissipation performance obtained by bringing a supporting plate into surface contact with a mounting face certainly. <P>SOLUTION: This mounting structure 10 of electronic parts is provided with a supporting plate 13 capable of face contacting via a sheet 12 to a mounting face 11, and a tip 15 placed in the supporting plate 13. Two screws 16 which penetrate two places of the right and left edge in the edge 13A of the supporting plate 13 are attached by screw fitting in a thickness direction to the fitting hole 11A of a mounting face 11. Further, it is provided with a pressing member 18 which presses the tip 15 to the mounting face 11, comprising seats 19 by the side of the right and left in the supporting plate 13 placed by the pressing member 18 and tightened together by the screws 16, and a contact 21 connected with the seats 19 in the right and left sides in elastic contact with the upper surface 15A of the tip part 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mounting structure for an electronic component that includes a support plate that can be brought into surface contact with a mounting surface and a chip portion that is placed on the support plate, and that clamps a plurality of locations on the edge of the support plate.

For example, electronic components such as field effect transistors (hereinafter referred to as “FETs”) used in each electronic device are placed on a support plate that can be brought into surface contact with a metal mounting surface. And a plurality of screws that penetrate through a plurality of edges of the support plate in the thickness direction to the mounting surface.
The chip portion includes a chip body placed on the support plate and a box-shaped lid that covers the chip body. By bringing the support plate into surface contact with the mounting surface, good heat dissipation and electrical conductivity are obtained for the electronic component.

However, there may be a gap between the mounting surface and the center portion of the support plate due to manufacturing errors. If the gap is generated, desired heat dissipation and electrical conductivity cannot be obtained, and performance as an electronic device cannot be guaranteed.
In addition, thermal expansion due to self-heating of the electronic component may cause the support plate to bend and create a gap.

As countermeasures, a mounting structure has been proposed in which a copper foil sheet is interposed between the mounting surface and the support plate, or grease is applied between the mounting surface and the support plate. (For example, Patent Document 1).
JP 2002-353388 A

  By the way, as shown in FIG. 7, in the mounting structure 100 in which the sheet 103 is interposed between the mounting surface 101 and the support plate 102, screws 104 are passed through the left and right edges 102 </ b> A of the support plate 102. The screw 104 is screwed onto the mounting surface 101.

Since the mounting structure 100 only tightens the left and right edges 102A of the support plate 102 with screws 104, for example, due to manufacturing errors of the support plate 102 or thermal expansion of the support plate 102 due to self-heating of the chip portion 105, The mounting surface 101 and the central portion 102B of the support plate 102 are lifted upward.
For this reason, there is a limit in relaxing the gap generated between the mounting surface 101 and the central portion 102B of the support plate 102 with the metal stay sheet.

On the other hand, as shown in FIG. 8, when the mounting structure 110 that applies the grease 111 between the mounting surface 101 and the support plate 102 is employed, the gap is generated between the mounting surface 101 and the central portion 102 </ b> B of the support plate 102. It is possible to reduce the gap.
However, since the grease 111 does not have electrical continuity, if the mounting structure 110 is employed, the grounding (ground) of the chip portion 105 is weak or cannot be grounded, and thus the electrical characteristics may become unstable.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic component mounting structure in which good heat dissipation and electrical conductivity can be obtained by reliably bringing a support plate into surface contact with a mounting surface. And

  An electronic component mounting structure according to the present invention includes a support plate that can be brought into surface contact with a mounting surface, and a chip portion that is placed on the support plate. A mounting structure of an electronic component that is mounted by screwing a plurality of penetrating screws to the mounting surface, and includes a pressing member that presses the chip portion toward the mounting surface, and the pressing member includes the support It has a seat part mounted on a board and fastened together with the screw, and a contact part connected to the seat part and elastically contacting the upper surface of the chip part.

By fastening the seat portion of the pressing member to the support plate with a screw, the contact portion is elastically brought into contact with the upper surface of the tip portion, and the tip portion is pressed toward the mounting surface by the pressing member.
Thus, the entire support plate can be brought into uniform contact with the mounting surface by the screw tightening force and the elastic contact of the contact portion, and the support plate can be reliably brought into surface contact with the mounting surface.

  The electronic component mounting structure according to the present invention is characterized in that the pressing member includes a plurality of the seat portions, and the contact portions are connected to the seat portions.

  By tightening a plurality of seats together with screws, the tightening force of each screw is transmitted to the contact portion. Therefore, the pressing force of the contact portion with respect to the tip portion is increased, and the support plate can be more reliably brought into surface contact with the mounting surface.

  The electronic component mounting structure according to the present invention is characterized in that the contact portion is formed so as to contact only an edge portion on an upper surface of the chip portion.

By bringing the contact portion into contact with only the edge portion on the upper surface of the tip portion, it becomes possible to apply a pressing force by the contact portion to the side wall of the tip portion.
Therefore, the pressing force by the contact portion can be efficiently transmitted to the support plate through the side wall of the tip portion, and the support plate can be more reliably brought into surface contact with the mounting surface.

  According to the present invention, the entire support plate is brought into uniform contact with the mounting surface by the screw tightening force and the elastic contact of the contact portion, so that the support plate is reliably brought into surface contact with the mounting surface and good heat dissipation is achieved. And electrical conductivity can be obtained.

  As shown in FIGS. 1 to 2, the electronic component mounting structure 10 according to the first embodiment includes a support plate 13 that can be brought into surface contact with a metal mounting surface 11 via a sheet 12, and a support plate 13. And a plurality of (two) screws 16 penetrating through a plurality of locations (two locations at the left and right ends) of the edge portion 13A of the support plate 13 in the thickness direction. The pressing member 18 is attached by screwing into the mounting hole 11A of the surface 11 and presses the tip portion 15 toward the mounting surface 11. The pressing member 18 is placed on the support plate 13 and attached to the screw 16. The left and right side seat portions 19 are fastened together, and the contact portion 21 is connected to the left and right side seat portions 19 and elastically contacts the upper surface 15A of the chip portion 15.

The sheet 12 is obtained by embossing (unevening) a copper foil. When the support plate 13 is attached to the attachment surface 11 with the screws 16, the embossing of the sheet 12 is crushed by interposing the support plate 13 along the entire surface of the support plate 13 between the attachment surface 11 and the support plate 13. fill in. In addition, the sheet | seat 12 is + surface contact.
Here, the gap between the mounting surface 11 and the support plate 13 is generated when the support plate 13 is bent due to thermal expansion due to a manufacturing error of the support plate or self-heating of the chip portion 15.

  The support plate 13 is a substantially rectangular plate material in which the chip portion 15 is placed substantially at the center and the recesses 23 are formed in the left and right edge portions 13A. The left and right recesses 23 are formed so that the screws 16 can be inserted.

The chip unit 15 includes a chip main body 24 placed on the support plate 13 and a box-shaped lid unit 25 that covers the chip main body 24.
By bringing the support plate 13 into surface contact with the mounting surface 11 via the sheet 12, good heat dissipation and electrical conductivity can be obtained in the chip body 24.

The pressing member 18 has a plurality of seat portions 19 (two on the left and right sides as an example), and each seat portion 19 is connected to the contact portion 21.
The contact portion 21 includes a left and right vertical piece 27 and a pressing piece 28 that spans between the upper ends of the left and right vertical pieces 27, and is formed in a substantially M shape by the left and right vertical portions 27 and the pressing piece 28. . The holding piece 28 is formed in a substantially square shape by bending the central portion 28 </ b> A downward.

  The left seat 19 is provided at the lower end of the pair of left vertical pieces 27 and the right seat 19 is provided at the lower end of the pair of right vertical pieces 27 in a state where the pair of contact portions 21 are arranged at a predetermined interval. ing. In other words, the pair of contact portions 21 are attached to the left and right seat portions 19 at a predetermined interval.

The left-right seat 19 is formed with insertion holes 19A into which the screws 16 can be inserted.
The pressing member 18 is assembled by inserting screws 16 into the left and right insertion holes 19A and fastening the support plate 13 and the seat portion 19 together with the inserted screws 16. In this state, the central portion 28A of the pressing piece 28 comes into contact with the upper surface 15A of the chip portion 15 and presses the upper surface 15A of the chip portion 15.

Here, as shown in FIG. 3, when the center portion 28A of the pressing piece 28 comes into contact with the upper surface 15A of the tip portion 15, the interval between the seat portion 19 and the support plate 13 is set to S1.
On the other hand, the bending which occurs when the support plate 13 is attached to the attachment surface 11 via the sheet 12 in a state where the chip portion 15 is placed on the support plate 13 is defined as S2. The relationship between S1 and S2 is S1> S2.
As an example, S1 = 1 mm or more, and S2 = 20 μm (micron).

Therefore, as shown in FIG. 4, when the left and right seats 19 of the pressing member 18 are fastened together with the screws 16 to the support plate 13, the pressing member 18 (particularly, the pressing piece 28) is elastically deformed.
In this manner, by pressing the seat portion 19 of the pressing member 18 together with the support plate 13 with the screw 16, the central portion 28A of the contact portion 21 is brought into elastic contact with the upper surface 15A of the tip portion 15 so that the pressing member 18 The tip portion 15 is pressed toward the mounting surface 11.

  Therefore, the entire support plate 13 is uniformly brought into contact with the mounting surface 11 by the tightening force of the screw 16 and the elastic contact of the central portion 28 </ b> A of the contact portion 21. Can be contacted.

Furthermore, by tightening the left and right seats 19 together with the screws 16, the tightening force of each screw 16 is transmitted to the contact portion 21.
Therefore, by connecting the plurality of seats 19 to the contact part 21, it is possible to transmit the tightening force by the plurality of screws 16 to the contact part 21.
As a result, the pressing force of the contact portion 21 against the tip portion 15 is increased, and the support plate 13 can be brought into surface contact with the mounting surface 11 more reliably.

  Here, as shown in FIG. 5A, the electronic component mounting structure 10 has a pair of contact portions 21 arranged at a predetermined interval so that each contact portion 21 has an upper surface 15 </ b> A of the chip portion 15. It is formed so as to contact only the edge 15B.

In this way, by bringing the central portion 28A of the contact portion 21 into contact only with the edge portion 15B on the upper surface 15A of the tip portion 15, the pressing force F1 by the contact portion 21 can be applied to the side wall 15C of the tip portion 15. Become.
Therefore, the pressing force by the contact portion 21 is efficiently transmitted to the support plate 13 through the side wall 15C of the tip portion 15.

  On the other hand, as shown in the comparative example of FIG. 5B, the contact portion 59 of the pressing member 58 of the comparative example is integrally formed, and the central portion 15D of the tip portion 15 is pushed by the central portion 59A of the contact portion 59. When pressed with the pressure F2, the central portion 15D of the lid portion 25 may be deformed and come into contact with the chip body 24.

Furthermore, as shown in FIG. 6 (A), the electronic component mounting structure 10 has a pair of contact portions 21 arranged at a predetermined interval so that the contact portions 21 are twisted in the direction of the arrow. Even in this case, the pair of contact portions 21 can apply a pressing force to the edge portion 15B of the upper surface 15A of the tip portion 15.
Thereby, it becomes possible to apply the pressing force by the contact portion 21 to the side wall 15C of the tip portion 15, and the pressing force by the pair of contact portions 21 is efficiently transmitted to the support plate 13 through the side wall 15C of the tip portion 15.

On the other hand, as shown in the comparative example of FIG. 6B, if the contact portion 59 of the pressing member 58 of the comparative example is formed integrally, if the contact portion 59 is twisted in the direction of the arrow, the contact portion The pressing force is applied only to one edge 15B of the upper surface 15A of the tip 15 at the edge 59B of 59.
For this reason, the pressing force is biased toward the tip portion 15, and it is difficult to press the tip portion 15 against the support plate 15 uniformly.

  In the above-described embodiment, the example in which the pressing piece 28 of the pressing member 18 is bent in a substantially square shape and the upper surface 15A of the tip portion 15 is pressed by the central portion 28A has been described. It is also possible to form 28 in a curved shape.

Further, in the above-described embodiment, the example in which the mounting holes for the screws 16 are formed in the left and right edge portions 13A of the supporting portion 13 and the supporting plate 13 is tightened with the screws 16 inserted into the mounting holes has been described. In addition to the left and right edge portions 13 </ b> A, the front and rear edge portions can be tightened with screws 16.
In this case, the tightening force of the four screws 16 can be transmitted to the pressing piece 28 of the pressing member 18, so that the upper surface 15 </ b> A of the tip portion 15 can be pressed more strongly with the pressing piece 28.

  The present invention includes a support plate that can be brought into surface contact with the mounting surface, and a chip portion that is placed on the support plate, and is applied to an electronic component mounting structure that tightens a plurality of locations on the edge of the support plate. Is preferred.

It is a disassembled perspective view which shows the attachment structure of the electronic component which concerns on this invention. It is a perspective view which shows the attachment structure of an electronic component in this invention. It is a figure explaining the characteristic of the attachment structure of the electronic component which concerns on this invention. It is a side view of the electronic component mounting structure according to the present invention. It is a figure explaining the pressing force of the attachment structure of the electronic component which concerns on this invention. It is a figure explaining the case where the attachment structure of the electronic component which concerns on this invention is twisted. It is a side view which shows the attachment structure of the conventional electronic component. It is a side view which shows the attachment structure of another conventional electronic component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electronic component mounting structure 11 Mounting surface 13 Support plate 13A Edge of support plate 15 Chip portion (electronic component)
16 Screw 18 Pressing member 19 Seat part 21 Contact part

Claims (3)

A support plate that can be brought into surface contact with the mounting surface, and a chip portion that is placed on the support plate, and a plurality of screws that penetrate a plurality of locations in the edge of the support plate in the thickness direction are provided on the mounting surface. An electronic component mounting structure that is mounted by screwing,
A pressing member that presses the tip portion toward the mounting surface;
The pressing member is placed on the support plate and seated together with the screw;
An electronic component mounting structure comprising: a contact portion connected to the seat portion and elastically contacting the upper surface of the chip portion.   The electronic component mounting structure according to claim 1, wherein the pressing member includes a plurality of the seat portions, and the contact portions are connected to the seat portions.   3. The electronic component mounting structure according to claim 1, wherein the contact portion is formed so as to contact only an edge portion on an upper surface of the chip portion.

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