JP2705369B2 - Electronic equipment - Google Patents

Abstract

PURPOSE:To prevent the outflow of an adhesive used for the junction between a frame body and a circuit board. CONSTITUTION:This has a frame body 10, where a stairs-shaped stepped part 21 which has a horizontal plane 21h which contacts with the periphery on the side of the wiring face of a circuit board 50 and is joined with the circuit board with an adhesive is made at the inner sidewall, and at the wiring face of the circuit board is made the dummy wiring 54 by a circuit pattern which is made inside a minute interval apart from the inside boundary 21a of the contact area with the horizontal plane. It follows that the surplus adhesive, which is protruded out of the adhesive interposed between the horizontal plane and the circuit board, comes to be reserved in the minute space between the inside boundary and the dummy wiring, and the adhesive is prevented from flowing into the wiring face of the circuit board over the dummy wiring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having an improved mounting density, and more particularly to a device which facilitates bonding of a substrate to a frame and prevents occurrence of defective products.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus in which a circuit board on which a semiconductor integrated circuit is mounted is mounted in two stages in one package (for example, Japanese Patent Application Laid-Open No. 1-147850). In this device, a circuit board having a two-stage structure is attached in a package with an adhesive.

[0003]

However, in such an electronic device, there is no contrivance for joining the substrate to the package with an adhesive, and the extra adhesive that protrudes from the joint surface is reduced.
It protrudes onto its own substrate surface or falls on the substrate below. For this reason, the excess adhesive adheres to the electrical connection portion on the substrate to cause a connection failure or abnormal transmission of bonding power at the time of bonding, resulting in low-reliability bonding. In addition, the adhesive adheres to the electrical connection leads between the substrates, causing a connection failure. Further, the heat dissipation effect is deteriorated due to the adhesive, and the difference in the thermal expansion coefficient and the viscosity between the adhesive and the substrate, the connection lead, or the like causes distortion or cracks or deteriorates the characteristics. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it easy to join a circuit board into a package in an electronic device having the circuit board mounted thereon, and to provide an electronic circuit using an adhesive. And to prevent poor connection.

[0005]

In order to solve the above-mentioned problems, the present invention provides a case, which comprises a case, a horizontal surface which is in contact with a peripheral portion of a circuit board on a wiring surface side, and which is joined to the circuit board with an adhesive. A stepped portion having a frame having an inner wall formed on an inner side wall, and formed on a wiring surface of the circuit board at an inner side with a small interval from an inner boundary line of a contact area with a horizontal plane; Characterized in that a dummy wiring is formed by a circuit pattern. Another feature is that a notch is formed on the inner boundary side of the horizontal surface of the stepped portion.

[0006]

The peripheral portion on the wiring surface side of the circuit board and the horizontal surface of the stepped portion formed on the frame are joined by an adhesive. At this time, the excess adhesive flows out to the wiring surface of the circuit board over the inner boundary of the contact area with the horizontal surface of the circuit board.

However, on this circuit board, a dummy wiring of a circuit pattern is formed on the inner side with a small gap from the inner boundary. For this reason, excess adhesive is stored in the minute gap between the inner boundary line and the dummy wiring, and the adhesive is prevented from flowing over the dummy wiring and into the wiring surface of the circuit board. You. Therefore, it may adversely affect the electronic circuit mounted on the board,
It does not adhere to the connection portion on the substrate and cause a connection failure. In addition, the occurrence of cracks and the deterioration of the heat radiation effect due to the difference in thermal expansion coefficient and viscosity between the substrate and the adhesive are prevented. Further, since the notch is formed on the inner boundary side of the horizontal plane, the adhesive is stored in the space formed by the notch and the substrate, and does not leak to other portions.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments. FIG. 1 is a sectional view of an electronic device 1 according to the present embodiment, FIG. 2 is a perspective view of a frame body 10, and FIG.
FIG. 4 is a perspective view of an apparatus in which a lower first circuit board 50 is mounted, FIG. 4 is a perspective view of an apparatus in which a second circuit board 52 is mounted in the middle of the frame 10, and FIG. FIG.

(1) Overall Structure of the Apparatus As shown in FIG. 5, the frame body 10 is made of resin and has a substantially rectangular parallelepiped shape. The frame 10 has an upper opening 12 opened to the external space on the upper side in the illustrated state and a lower opening 11 opened to the external space on the lower side. On the inner surface of the frame 10, the first stepped portion 21, the second stepped portion 22, and the like are arranged in a stepwise manner from the side of the lower opening 11.
Third stepped portion 23, fourth stepped portion 24, fifth stepped portion 2
5 are formed. Each stepped part 21, 22, 23, 2
4 and 25 respectively have normals in the Y-axis direction (vertical axis direction)
21h, 22h, 23h, 24h, 25
h and the vertical surface 21 in which the normal line points in the X-axis direction (horizontal axis direction)
v, 22v, 23v, 24v, and 25v.

As shown in FIG. 6, a first circuit board 50 is formed by forming an insulating layer on a metal plate 40 made of aluminum.
A circuit pattern is formed on the surface of the insulating layer. The circuit board integrally formed on the metal plate 40 is usually called a metal board. And the first
The peripheral portion 50a (FIG. 6) of the circuit board 50 is bonded to the horizontal surface 21h of the first stepped portion 21 with an adhesive.
The lower opening 11 is shielded by a metal plate 40. still,
The height of the vertical surface 21v of the first stepped portion 21 is equal to the thickness of the metal substrate on which the metal plate 40 and the first circuit board 50 are integrated, and the bottom surface 13 of the frame 10 and the metal plate The back surface 41 of 40 forms the same plane.

As shown in FIGS. 1 and 3, a large current is applied to a power MO
A power supply circuit 51 including a so-called power element such as an S transistor and a power transistor is mounted.

As shown in FIGS. 1 and 19, the metal plate 43 is disposed on the third stepped portion 23. That is, the rear surface 44 of the metal plate 43 is provided on the horizontal surface 23 h of the third stepped portion 23.
Are joined by an adhesive. A second circuit board 52 is bonded to the surface 45 of the metal plate 43 with an adhesive. On the second circuit board 52, a control circuit 5 that handles a relatively small current and generates a small amount of heat is provided.
3 has been implemented. The power supply circuit 51 and the control circuit 53 are coated with the silicone gel 16 as shown in FIG. This gel may be another resin in addition to silicone. Since this gel has a heat insulating effect, if an element for handling a large current is formed on the second circuit board 52, the heat from the element causes the first circuit board 50 to generate heat due to the action of the gel thereon. The heat is accumulated between the second circuit board 52 and the second circuit board 52 and cannot go out of the device. According to the structure of the present invention, the heat generated from the elements formed on the first circuit board 50 can be radiated to the outside through the metal plate 40 having a high heat dissipation effect, Does not generate much heat, the heat does not stay inside the device.

A metal plate 46 for shielding the upper opening 12 is provided on the fifth stepped portion 25 of the frame 10. That is, the peripheral portion of the back surface 47 of the metal plate 46 is joined to the horizontal surface 25h of the fifth stepped portion 25 with an adhesive. And
The surface 48 of the metal plate 46 is in contact with the outside air. Thus, the case of the electronic device 1 is configured by the frame body 10, the metal plate 40, and the metal plate 46. In this apparatus, an aluminum metal plate 40 for shielding the lower opening 11 of the resin frame 10 and an aluminum metal plate 43 in the middle stage of the frame 10 are provided. Since the second circuit board 52 is provided, even when the present apparatus is placed in a high-temperature environment such as an engine room of an automobile, the warpage caused by the difference in the coefficient of thermal expansion between the resin of the frame body 10 and the metal plate. Is prevented, and a second circuit board 52 made of ceramics is formed.
Thus, a decrease in reliability such as cracks in the semiconductor device and poor bonding at the bonding portion on the second circuit board 52 is prevented. The upper opening 1 of the frame 10
Since the metal plate 46 made of aluminum is also provided in 2,
The warpage of the frame body 10 and the bonding failure of the bonding portion on the circuit board caused by the warpage are further prevented. In addition,
Since the apparatus having the structure shown in FIG. 1 of 1-147850 is composed of a resin frame and a metal lid member, the frame is warped due to the difference in the coefficient of thermal expansion between the resin and the metal. There is a possibility that the ceramic substrate provided inside may be broken or the reliability of the joint on the substrate may be deteriorated.

On the other hand, a connector case 14 is formed on one side of the frame 10, and lead pins 60 and 61 project inside the connector case 14. The lead pin 60 is formed by bending a metal plate on which a number of leads are formed in a comb shape shown in FIG. 7 as shown in FIG.
0 is embedded by insert molding. As shown in FIG. 1, a pin 60a formed at one end of the lead pin 60 protrudes into the internal space of the connector case 14, and a bonding portion 6 formed at the other end.
0b is installed on the horizontal surface 22h of the second stepped portion 22 in an exposed state. The bonding portion 60b is a bonding portion 81 of the wiring pattern on the first circuit board 50.
And are electrically connected by wire bonding.

Similarly to the lead pin 60, the metal plate shown in FIG. 9 is bent into the shape shown in FIG. 10, and the lead pin 61 is embedded in the frame 10 by insert molding. The pin 61a formed at one end of the lead pin 61 projects into the internal space of the connector case 14, and the bonding portion 61 formed at the other end.
b is installed on the horizontal surface 24h of the fourth stepped portion 24 in an exposed state. The bonding portion 82 of the wiring pattern on the second circuit board 52 and the bonding portion 61b of the lead pin 61 are electrically connected by wire bonding. In the lead pins 60 and 61, the frame portions 60c and 61 holding the respective leads in common are provided.
c is cut with a cutter after resin molding, and each lead is electrically insulated.

A connection lead 63 which electrically connects only the first circuit board 50 and the second circuit board 52 and does not project pins for taking out signals to the outside is inserted into the frame 10. It is buried by molding. The connection lead 63 is formed by bending a comb-shaped metal plate shown in FIG. 11 into a shape shown in FIG. The connection lead 63 is formed between the bonding portion 63 a exposed on the horizontal surface 22 h of the second stepped portion 22 and the horizontal surface 24 of the fourth stepped portion 24.
and a bonding portion 63b exposed on the top surface h, and a tip portion 63c thereof is bent downward of the frame body 10. Then, a frame 63 that holds each lead in common
d and 63e are cut by a cutter after resin molding, and the respective leads are mutually insulated. Then, the bonding portion 63
a is electrically connected to the bonding portion 81 of the wiring pattern on the first circuit board 50 by wire bonding, and the bonding portion 63b is electrically connected to the bonding portion 82 of the wiring pattern on the second circuit board 52 by wire bonding. It is connected to the. The connection leads 63 electrically connect a part of the wiring between the first circuit board 50 and the second circuit board 52.

Further, as shown in FIG. 2, a capacitor box 15 is formed on the side surface of the frame 10, and the capacitor box 15 has a capacitor 56, as shown in FIG.
57 are stored in a lying state. The capacitors 56 and 57 are connected to the first circuit board 5 due to the mounting space.
0 and cannot be arranged on the second circuit board 52. By housing the capacitors 56 and 57 having relatively large volumes and heights in the capacitor box 15 separately formed on the side surface of the frame body 10 as in the present embodiment, the overall mounting efficiency of the electronic device 1 can be improved. it can. The connection lead 64 electrically connected to the capacitor 56 is embedded in the frame 10 by insert molding. The connection lead 64 is shown in FIG.
Is bent into the shape shown in FIG. The connection lead 64 includes a bonding portion 64 a exposed on the horizontal surface 22 h of the second stepped portion 22, a terminal portion 64 b erected on the capacitor box 15, and a frame portion 64.
c. The frame portion 64c is cut by a cutter after the frame 10 is formed. Also, the bonding portion 64a
Is electrically connected to the wiring pattern of the first circuit board 50 by wire bonding, and the terminal portion 64b is connected to the leads 56a and 56b of the capacitor 56 by electric welding.

On the other hand, on the side opposite to the side where the connector case 14 of the frame 10 is formed, the comb-shaped metal plate shown in FIG. 15 is bent at a substantially right angle as shown in FIG. Bent into a U-shape (a shape with a handle in the U-shaped groove)
The connection lead 62 is embedded in the frame 10 by insert molding. The bonding portion 62 a formed at one end of the connection lead 62 is connected to the second stepped portion 2.
2 is installed on the horizontal surface 22h in an exposed state, and the intermediate portion 62
g is buried inside the frame body, the bonding portion 62b of the connection lead 62 is installed in an exposed state on the horizontal surface 24h of the fourth stepped portion 24, and the other tip portion 62c is connected to the first stepped portion 21.
Projecting into a groove 26 formed on the horizontal surface 21h of the first surface.
The frame portion 62d holding the respective leads in common is in a state of protruding into the groove 26 immediately after the molding of the frame body 10, but is thereafter cut by a cutter. Similarly, the frame portion 62e is cut after molding, and each lead is insulated and separated. At this time, cuts are formed in the frame portions 62d and 62e to facilitate cutting.

As shown in FIG. 1, the bonding portion 62a of the connection lead 62 and the bonding portion 83 of the wiring pattern of the first circuit board 50 are electrically connected by wire bonding. 62b and the bonding portion 84 of the wiring pattern of the second circuit board 52 are electrically connected by wire bonding. As described above, the electrical connection between the first circuit board 50 and the second circuit board 52 is performed using the connection leads 62.

Further, on the side of the frame 10 where the connection leads 62 are provided, adjacent to the connection leads 62, the connection leads 6 having the same shape as the connection leads 64 shown in FIG.
5 are buried. The connection lead 65 is composed of a bonding portion 65a exposed on the horizontal surface 22h of the second stepped portion 22, and a terminal portion 65b provided upright in the capacitor box 15. And the bonding section 6
5a and the wiring pattern of the first circuit board 50 are electrically connected by wire bonding, and the lead portion 57b of the capacitor 57 is connected to the terminal portion 65b by electric welding.

(2) Detailed Configuration of Metal Substrate (Metal Plate 40, First Circuit Board 50) On the first circuit board 50, as shown in FIG. 6, a circuit for the power supply circuit 51 shown in FIG. Wiring is formed.
Then, in a state where the first circuit board 50 is attached to the first stepped portion 21, the horizontal surface 21h of the first stepped portion 21 is formed.
From the inner boundary line 21a shown in FIGS.
Dummy wirings 54 are formed so as to protrude inwardly with a space therebetween. Further, a concave portion 55 where no wiring is formed is formed inside the dummy wiring 54.

The functions of the dummy wiring 54 and the concave portion 55 are as follows. When the first circuit board 50 formed on the metal plate 40 is bonded to the horizontal surface 21h of the first stepped portion 21 with an adhesive, the excess adhesive may pass over the inner boundary 21a of the horizontal surface 21h for the first time. Flows into the inside of the circuit board 50 of
The adhesion to the connection portion 59 of the integrated circuit 58 mounted on the first circuit board 50 causes a connection failure, or abnormal conduction of bonding power occurs during bonding, thereby lowering the reliability of bonding. In addition, they adhere to the bonding portions 81, 83, etc. of the circuit wiring and cause bonding failure. At this time, as shown in FIG. 17, the dummy wiring 54 formed on the first circuit board 50 is
It works to prevent inflow of water. That is, the excess adhesive 17 is stored in the minute gap Δ1 between the boundary line 21a of the horizontal surface 21h and the dummy wiring 54. In addition, there is a lot of excess adhesive, and it gets over the dummy wiring 54, and further,
Even if the adhesive flows into the inside of the first circuit board 50, the adhesive is trapped in the recess 55 formed inside the dummy wiring 54 and does not flow into the inside of the recess 55.
As a result, damage to the element by the adhesive is prevented,
The occurrence of wire bonding failure is prevented. The dummy wiring 54 is a line irrelevant to the electric wiring or a ground line.

(3) Detailed Configuration of First Stepped Part 21 The first stepped part 21 has a horizontal surface 21 as shown in FIG.
A notch 21b is formed on the inner boundary line 21a side of h. The notch 21b may be cut diagonally as shown in the figure, or may be cut in a square or U-shape as shown in FIGS. 18 (a) and 18 (b).

The function of the notch 21b is as follows. When the first circuit board 50 formed on the metal plate 40 is bonded to the first stepped portion 21 with an adhesive, the excess adhesive 17 is cut off by the notch 21b, the surface of the first circuit board 50, and the dummy. Wiring 54
Is stored between As a result, excess adhesive 17 is prevented from flowing into the first circuit board 50, and the influence of the adhesive on the integrated circuit 58 of the power supply circuit 51 can be prevented.

Further, the excess adhesive 17 is applied to the second stepped portion 22.
Of the lead pin 60, the bonding portion 63a of the connection lead 63, the bonding portion 64a of the connection lead 64, and the bonding portion 62a of the connection lead 62 disposed on the horizontal surface 22h. In addition, it is possible to prevent wire bonding failure from occurring due to the adhesive 17 adhering to the bonding portion 65a of the connection lead 65.

(4) Detailed configuration of the third stepped portion 23 As shown in FIG. 19, the horizontal surface 23h of the third stepped portion 23
The groove 23b is formed on the inner boundary line 23a side of the outer boundary line 23c.
A groove 23d is formed in the groove. The grooves 23b and 23d may have a triangular shape in addition to the illustrated square shape. or,
The structure may be similar to that of FIG.

A groove 23b formed in the third stepped portion 23;
The operation of 23d is as follows. When the metal plate 43 is bonded to the horizontal surface 23h of the third stepped portion 23 with an adhesive, excess adhesive 17 is stored in the groove 23b. As a result,
The surplus adhesive 17 is located on the second surface below the horizontal surface 23h.
Of the lead pin 60, the bonding portion 63a of the connection lead 63, the bonding portion 64a of the connection lead 64, and the connection lead 62, which are prevented from hanging down on the horizontal surface 22h of the stepped portion 22. Bonding part 62a and connection lead 6
5 can prevent wire bonding failure from occurring due to adhesion of the adhesive to the bonding portion 65a. Also, the groove 23b prevents the silicone gel 16 filled on the first circuit board 50 from rising on the horizontal surface 23h of the third stepped portion 23, so that the adhesive is easily attached to the horizontal surface 23h, Adhesion failure between 23h and metal plate 43 is prevented. The third of the silicone gel 16
In order to prevent the horizontal surface 23h of the stepped portion 23 from rising, the vertical surface 22v of the second stepped portion 22
A stepped portion projecting perpendicularly to v may be formed.

The excess adhesive 17 is also stored in the groove 23d. As a result, the extra adhesive 17 is removed from the third stepped portion 2.
3 and is attached to the wiring pattern of the second circuit board 52 joined on the metal plate 43, and is disposed on the horizontal surface 24h of the fourth stepped portion 24. Therefore, it is possible to prevent the bonding to the bonding portion 61b of the lead pin 61, the bonding portion 63b of the connection lead 63, and the bonding portion 62b of the connection lead 62, thereby preventing the occurrence of wire bonding failure.

(5) Specific Structure of the Metal Plate 43 As shown in FIGS. 19 and 20, the metal plate 43 has a shape slightly smaller than the shape shown by the outer boundary line 23c of the horizontal surface 23h of the third stepped portion 23. When the metal plate 43 is placed on the horizontal surface 23h, a small gap Δ2 is formed between the metal plate 43 and the vertical surface 23v. Several projections 43a are formed on the peripheral edge of the metal plate 43 toward the outside (in the direction of the vertical surface 23v). On the vertical surface 23v, several projections 23e are formed inward (in the direction of the metal plate 43).

The operation of the projections 43a and 23e is as follows. The protrusions 43a and 23e are provided on the third stepped portion 2 of the metal plate 43.
3 is for positioning when placed on the substrate 3, and for forming a minute gap Δ2 between the metal plate 43 and the vertical surface 23v. Further, the bonding portion 61b of the lead pin 61, the bonding portion 63b of the connection lead 63, and the bonding portion 6 of the connection lead 62
2b and the metal plate 43 are insulated and separated. The extra adhesive 17 is stored in the minute gap Δ2, and the adhesive 1
7 is prevented from racing up the vertical plane 23v. As a result, the extra adhesive 17 is removed from the vertical surface 23 of the third stepped portion 23.
v, and adheres to the wiring pattern of the second circuit board 52 joined to the metal plate 43, and the lead pins 61 arranged on the horizontal surface 24h of the fourth stepped portion 24. Adhesion to the bonding portion 61b and the bonding portion 62b of the connection lead 62 is prevented, and the occurrence of wire bond failure can be prevented.

(6) Detailed Configuration of Fifth Stepped Part 25 As shown in FIG.
A groove 25b is formed on the side of the inside boundary line 25a. The groove 25b may have a triangular shape in addition to the illustrated rectangular shape. Further, the structure may be the same as that shown in FIG.

The function of the groove 25b formed in the fifth stepped portion 25 is as follows. The metal plate 46 is the fifth stepped portion 25
Is bonded to the horizontal surface 25h with an adhesive. At this time, excess adhesive 17 is stored in this groove. As a result, the excess adhesive drips from the horizontal surface 25h, and the fourth stepped portion 24
Wire bonding failure due to the adhesion to the bonding 61b of the lead pin 61 and the bonding 62b of the connection lead 62 disposed in the wiring. Also, the adhesive 17 is prevented from adhering to the wiring pattern of the second circuit board 52. Also, the grooves 25b prevent the silicone gel 16 filled on the second circuit board 52 from rising to the horizontal surface 25h of the fifth stepped portion 25, and the adhesive is easily attached to the horizontal surface 25h, Poor adhesion between the horizontal surface 25h and the metal plate 46 is prevented. In order to prevent the horizontal surface 25h of the fifth stepped portion 25 of the silicone gel 16 from rising, a stepped portion that projects perpendicularly to the vertical surface 24v is provided on the vertical surface 24v of the fourth stepped portion 24. It may be formed.

(7) Detailed Configuration of Lead Pins 60 and 61 The lead pins 60 and 61 are respectively formed by bending the flat metal shown in FIGS. 7 and 9 into the shapes shown in FIGS. The pitch of each lead piece is determined by the bonding portion 60
It spreads from b, 61b toward the pins 60a, 61a. Since the distance between the leads on the pins 60a and 61a is widened and the distance between the leads on the bonding portions 60b and 61b is narrow in this manner, even if the inside of the frame 10 is narrow, the pin extraction efficiency is low. good. Also, lead pin 6
The cross-sectional shapes of 0 and 61 are trapezoidal as shown in FIG. Accordingly, the bonding portions 60b, 61b of the lead pins 60, 61 are respectively connected to the second stepped portions 2
2 are formed by insert molding on the horizontal surface 22h of the second step portion 24 and the horizontal surface 24h of the fourth stepped portion 24. At the time of manufacturing and wire bonding, the bonding portions 60b and 6 are formed.
1b is prevented from separating from the respective horizontal surfaces 22h, 24h.

(8) Detailed Configuration of Connection Leads 62, 63, 64, 65 The connection lead 62 is a metal plate having the shape shown in FIG.
Is bent in the shape shown in FIG. In the connection lead 62, the pitch of each lead is wider on the bonding portion 62b side than on the bonding portion 62a side. With this shape, the wiring patterns of the first circuit board 50 having a narrow bonding space and the second circuit board 52 having a wide bonding space can be electrically connected efficiently without reducing the number of leads. it can.

The connection lead 63 is obtained by bending the flat metal plate shown in FIG. 11 into the shape shown in FIG. 12, and the connection lead 64 is formed by converting the flat metal plate shown in FIG. 13 into the shape shown in FIG. It is bent. The connection lead 65 has the same shape as that of the connection lead 63. By using the connection leads 64 and 65 having this structure, the first circuit board 50 and the capacitors 56 and 57 provided in the capacitor box 15 formed on the frame 10 can be electrically connected.

The sectional shape of each of the connection leads 62, 63, 64, and 65 is trapezoidal as shown in FIG. Therefore, the bonding portions 62a, 63a, 64a, 65a of the connection leads 62, 63, 64, 65 are formed on the horizontal surface 22h of the second stepped portion 22 by insert molding. Of the bonding portions 62a, 63a, 64a, and 65a are prevented from separating from the horizontal surface 22h. Similarly, the bonding portions 62b and 63b of the connection leads 62 and 63
It is formed on the horizontal surface 24h of the fourth stepped portion 24 by insert molding.
The bonding portions 62b and 63b are prevented from coming off the horizontal surface 24h.

(9) Structure of the Back of the Frame 10 The back of the frame 10 is configured as shown in FIG.
The groove 26 from which the end portion 62c of the connection lead 62 and the frame portion 62d protrudes, and the groove 29 from which the end portion 63c of the connection lead 63 and the frame portion 63e protrude are formed. When the resin molding of the frame body 10 with the connection leads 62, 63 as inserts is completed, the respective frame portions 62d, 63e of the connection leads 62, 63 are cut in the grooves 26, 29.

Further, an intermediate portion 62f connected to the bonding portion 62a of the connection lead 62 embedded in the frame 10
(See FIG. 16) and an intermediate portion 60d connected to the bonding portion 60b of the lead pin 60 (see FIG. 8).
The windows 27 and 28 are formed at positions corresponding to. Among these, the window 27 is formed for placing a support plate 66 for supporting the connection lead 62 on the mold without deformation and displacement during the later-described manufacturing. Window 2
Reference numerals 7 and 28 are used to confirm whether the connection leads 62 and the leads of the lead pins 60 are formed without contact when the resin molding of the frame 10 is completed.

(10) Method of Manufacturing Electronic Device 1 The frame 10 is made up of lead pins 60 and 61, connection leads 62,
It is formed by resin molding using 63, 64 and 65 as inserts. As shown in FIG. 24, the mold mainly includes an upper mold 70, a lower mold 71, and a core (not shown). A cavity 72 for injecting resin is formed between the upper mold 70 and the lower mold 71. Lead pin 60,
61, 63, 64, 65 are supported on a core for forming the connector box 14.

On the other hand, the connection lead 62 is provided in the cavity 72 as follows. The tip 62c of the connection lead 62 and the frame 62d are inserted into the groove 68 formed in the lower die 71, and the frame 62e is
1 and the bonding portion 62b is
In contact with the cavity surface 72a. An intermediate portion 62f and an intermediate portion 62g following the bonding portion 62a are arranged in the cavity 72, and the intermediate portion 62f is supported by a comb-shaped support plate 66 protruding from a groove 69 formed in the lower die 71.

The method of supporting the connection lead 62 by the support plate 66 is described in detail in FIG. Each foot 66 of the support plate 66
is inserted into the gap between the leads of the connection lead 62, and each lead of the connection lead 62 is pressed in the direction of the upper die 70 by the base 66 b of the support plate 66. As a result, the connection lead 62
The gap between the leads is appropriately maintained, and the leads are prevented from coming into contact during the resin molding process.

Further, due to the pressing force f of the support plate 66 toward the upper mold 70, the bonding portions 62a and 62b
From the lower mold 71. As a result, the connection lead 62 is held in a proper posture in the cavity 72, and in the frame 10 after molding,
Bonding portions 62a and 62b of the connection lead 62 are horizontally exposed to a horizontal surface 22h of the second stepped portion 22 and a horizontal surface 24h of the fourth stepped portion 24, respectively.
Molding defects are prevented.

It should be noted that, as shown in FIG.
Is simply U-shaped, the connection leads 6
Since there is no intermediate portion (a portion corresponding to 62 g in FIG. 24) extending in the direction where the pressing force f of the support plate 66 acts on the bonding portion 620, the bonding portion 620 b in which the pressing force f comes into contact with the upper mold 70 does not exist. Difficult to communicate to. Therefore,
The force for pressing the bonding portion 620b against the upper die 70 is insufficient, and a gap is generated between the bonding portion 620b and the upper die 70. In this case, the resin may be injected into the gap and the bonding portion 620b may not be exposed. Further, the posture of the bonding portion 620b is inappropriate,
The bonding portion 620b may not be formed at a regular pitch.

However, by forming the connection lead 62 into a shape as shown in FIGS. 16 and 25, the bonding portion 62b is formed on the horizontal surface 24 of the fourth stepped portion 24 of the frame 10.
h can be appropriately formed. Since the pressing force f by the support plate 66 only needs to properly act on the connection lead 62, the shape of the connection lead 62 and the pressing force f by the support plate 66
May be as shown in FIG.

After the frame 10 is formed, the lead pins 6
0, 61, frame parts 60c, 61c, 62e, 62d, 63e, 63 of connection leads 62, 63, 64, 65
d and 64c are cut.

(11) Method for Connecting Capacitor 56 to Connection Lead 64 The terminal 64 b of the connection lead 64 is formed in a shape as shown in FIG. This terminal portion 64b is connected to the capacitor 5
Welding area 64 for electrically welding the six leads 56a, 56b
d is formed, and the welding area 64 d is formed in the notch 6
4f, the length of the welding region 64d in the axial direction (h-axis direction) is shorter than that in the width direction (d-axis direction). With such a configuration, the welding area 64 of the leads 56a and 56b is formed.
The contact area with respect to d can be reduced to increase the current concentration during electric welding. Further, since the leads 56a and 56b pass through the notch 64f, the leads 56a and 56b
Positioning of 56b and displacement during welding are prevented.
Also, the gap between the leads 56a and 56b is maintained, and no short circuit occurs even when the device is used in a place where vibration is severe. Also, the notch 64f and the leads 56a, 56
b are engaged, the vibration leads 56a, 5b
Transmission of 6b to the welded portion is alleviated, and peeling of the joint is suppressed.

The welding area 64d and the notch 64f may have the shapes shown in FIG. 29, and the current concentration can be increased during electric welding. As shown in FIG. 28, the lead 56a is inserted into the notch 6 as shown in FIG.
By bending the lead 56a through 4f, the positioning of the lead 56a and the displacement during welding are prevented. Similarly, even when the device is used in a place where vibration is severe, the occurrence of a short circuit between the leads is prevented, and the transmission of the vibration to the welded portion of the lead is eased. Is suppressed. Also, even when the electronic device 1 is installed in a place where vibration is severe, such as an engine room of an automobile, by providing such a notch portion 64f, the transmission of vibration to the terminal portion 64b is reduced, and an electric welding portion is provided. Is prevented from peeling off.

[0048]

According to the present invention, there is provided a frame body in which a stepped stepped portion having a horizontal surface and being in contact with a peripheral portion of a circuit board on a wiring surface side and having a horizontal surface joined with an adhesive is formed on an inner wall. And a dummy wiring is formed on the wiring surface of the circuit board by a circuit pattern wired on the inner side of the inner boundary line of the contact area with the horizontal plane at a small interval. Therefore, the excess adhesive extruded out of the adhesive interposed between the horizontal surface and the circuit board is stored in the minute gap between the inner boundary line and the dummy wiring. Over the wiring surface of the circuit board. Therefore, it does not adversely affect the electronic circuit mounted on the substrate or adhere to a connection portion (bonding portion) on the substrate to cause a connection failure. In addition, the occurrence of cracks and the deterioration of the heat radiation effect due to the difference in thermal expansion coefficient and viscosity between the substrate and the adhesive are prevented. In another invention, since the notch is formed on the inner boundary side of the horizontal surface of the stepped portion, excess adhesive for joining the horizontal surface and the substrate is stored in a space formed by the notch and the substrate, Does not flow outside. Therefore, there is an effect similar to the above.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an electronic device according to a specific example of the invention.

FIG. 2 is an exemplary perspective view showing a frame of the electronic device;

FIG. 3 is a perspective view showing a frame on which a first circuit board is mounted.

FIG. 4 is a perspective view showing a frame on which a second circuit board is mounted.

FIG. 5 is a sectional view showing a configuration of a frame.

FIG. 6 is a plan view showing a first circuit board.

FIG. 7 is a plan view showing a planar shape before bending a lead pin.

FIG. 8 is a perspective view showing a three-dimensional shape after bending the lead pin.

FIG. 9 is a plan view showing a planar shape of another lead pin before bending.

FIG. 10 is a perspective view showing a three-dimensional shape after bending the lead pin.

FIG. 11 is a plan view showing a planar shape of a connection lead before bending.

FIG. 12 is a perspective view showing a three-dimensional shape of the connection lead after bending processing.

FIG. 13 is a plan view showing a planar shape of another connection lead before bending processing.

FIG. 14 is a perspective view showing a three-dimensional shape of the connection lead after bending processing.

FIG. 15 is a plan view showing a planar shape of another connection lead before bending processing.

FIG. 16 is a perspective view showing a three-dimensional shape of the connection lead after bending processing.

FIG. 17 is a sectional view showing a detailed configuration of a first stepped portion.

FIG. 18 is a sectional view showing another configuration of the first stepped portion.

FIG. 19 is a sectional view showing a detailed configuration of a third stepped portion.

FIG. 20 is a plan view showing a configuration of a third stepped portion on which a metal plate is placed.

FIG. 21 is a sectional view showing a detailed configuration of a fifth stepped portion.

FIG. 22 is a sectional view showing a sectional structure of a lead.

FIG. 23 is a back view showing the concept of the back surface of the frame.

FIG. 24 is a cross-sectional view showing a relationship between a mold and connection leads according to a method of manufacturing a frame.

FIG. 25 is a perspective view showing a method of supporting connection leads during manufacturing of the frame.

FIG. 26 is a perspective view for explaining improper support due to an improper shape of the connection lead at the time of manufacturing the frame.

FIG. 27 is a perspective view showing a relationship between another shape of the connection lead and a method of supporting the connection lead when the frame is manufactured.

FIG. 28 is a perspective view showing a connection relationship between a terminal portion of the connection lead and the lead.

FIG. 29 is a plan view showing another structure of the terminal portion of the connection lead.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic device 10 ... Frame 11 ... Lower opening 12 ... Upper opening 13 ... Bottom 14 ... Connector case 15 ... Capacitor box 21 ... First stepped part 22 ... Second stepped part 23 ... Third
Stepped part 24 ... Fourth stepped part 25 ... Fifth stepped part 21h, 22h, 23h, 24h, 25h ... Horizontal plane 21v, 22v, 23v, 24v, 25v ... Vertical plane 21b ... Notch 23b, 23d ... Groove 23e: Projection 2
5b Groove 26, 29 Groove 27, 28 Window 40 Metal plate 43 Metal plate 43a Projection 46 Metal plate 50 First circuit board 52 Second circuit board 51 Power supply circuit 53 Control circuit 54 ... Dummy wiring 55 ... Recess 56,57 ... Capacitor 58 ... Integrated circuit 60 ... Lead pin 62 ... Lead pin 60a, 61a
... pins 60b, 61b ... bonding parts 62, 63, 64,
65 connection lead 62a bonding part 62b bonding part 62f, 62g middle part 63a, b, 64a, 65a
… Bonding part 64b, 65b… terminal part 66… support plate 70… upper die
71: Lower die 72: Cavity 81, 82, 83, 84: Bonding part

Claims (2)

(57) [Claims] 1. An electronic device in which a circuit board on which an electronic circuit is mounted is disposed in a case, the electronic device having a horizontal surface that is in contact with a peripheral portion of the circuit board on a wiring surface side and is bonded to the circuit board with an adhesive. A step-shaped stepped portion has a frame formed on an inner side wall, and is formed on a wiring surface of the circuit board at a minute distance from an inner boundary line of a contact area with the horizontal plane. An electronic device, wherein a dummy wiring is formed by a circuit pattern. 2. The electronic device according to claim 1, wherein a notch is formed on the inner boundary side of a horizontal plane of the stepped portion.