JPH09270486A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent imperfect contact by preventing the movement of connected portions of electronic components. SOLUTION: A pair of leads 80 and 82 of LED(light emitting diode) are connected with a wire 84, and this connecting portion is fixed with a fixing portion 86 made of a resin. Notch-shaped receiving portions 34 and 36 are formed at the leads 80 and 82. After bending the leads 80 and 82, the leads are passed through a heating furnace for hardening adhesive and also immersed into molten solder. At this time, the receiving portions 34 and 36 are deformed to prevent the movement of the connecting portion and a stress is decreased. That is, a residual stress acts as a result of the bending of the leads 80 and 82 and the fixing portion 86 made of resin is heated under this acting state, then the leads 8 and 82 move in a direction of bending by a residual stress. Because of this, the connection at the connecting portion is likely to be separated but the receiving portions 34 and 36 are deformed, stress is decreased and the connecting portion does not move. Thus, imperfect contact at the connecting portion decreases and the number of times of unlighted LEDs decreases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component such as a light emitting diode which is mounted on a wiring board by soldering.

[0002]

2. Description of the Related Art In general, a light emitting diode LED, which is a photoelectric conversion element, is pn-junctioned and emits light such as red by passing a forward current. This light emitting diode L
The structure of the ED is shown in FIG. Head 80A of anode 80 which is an anode lead and cathode 82 which is a cathode lead,
A bonding wire 84 is connected between 82A.
Head 80 with bonding wire 84 connected
A fixing portion 86 is formed by fixing A and 82A with a synthetic resin. Foot portions 80B and 82 of the anode 80 and the cathode 82
B protrudes from the fixing portion 86 except the root portions 80C and 82C.

Although the light emitting diode LED is not shown,
It is manufactured by the following procedure. Anode 80 and cathode 82
Is integrally formed by pressing so that the foot portions 80B and 82B are continuous. The bonding wire 84 is formed by spot welding or the like at the head 80A between the anode 80 and the cathode 82,
It is thermocompression bonded to 82A.

In this state, the heads 80A and 82A to which the bonding wires 84 are connected are inserted into a mold having the shape of the fixing portion 86 shown in FIG. 11, and the resin is melted in the mold in this inserted state. Inject the liquid. Thereby, the light emitting diode LED as shown in FIG. 11 is molded.

The light emitting diode LED is mounted on a printed wiring board using an automatic mounting apparatus. That is, the foot 80B,
82B is inserted into a lead insertion hole formed in a printed wiring board (not shown), and the foot portion 80 protruded from the lead insertion hole.
B and 82B are cut with a cutting tool (not shown) to an appropriate length, and the legs 80B and 82B are bent in a predetermined direction as appropriate.

Other electronic components are mounted on the printed wiring board by using an automatic mounting apparatus. Among the other electronic components to be mounted, there is one in which the electronic component is simply placed on the printed wiring board in a state where its foot is in contact with the wiring circuit conductor (land). Therefore, when soldering is performed by the solder dip method, since the printed wiring board is turned over, the electronic component that has just been placed falls.

Therefore, in order to prevent the electronic parts from falling,
Before soldering, a printed wiring board corresponding to the electronic component is coated with an adhesive to bond the electronic component, and then the adhesive is cured. For example, 130 °
A printed wiring board on which a plurality of electronic components are mounted is passed through a heating furnace that is held at ˜140 °. After that, the parts that cannot be mounted by the automatic mounting apparatus are manually inserted so that the feet correspond to the lead insertion holes.

Then, the printed wiring board 26 is set to 100 °
After holding at a temperature of ~ 130 ° for a predetermined time, the surface of the printed wiring board is exposed to, for example, 250 ° molten solder for 3 ~.
Dip for 4 seconds and solder.

[0009]

By the way, when the light emitting diode LED is mounted on the printed wiring board, the foot portion 8 is formed.
Although 0B and 82B are bent and plastically deformed, stress (residual stress due to plastic deformation) acts on the anode 80 and the cathode 82 by this bending. When the fixing portion 86 is heated (specifically, it is passed through a heating furnace for fixing the above-mentioned adhesive or immersed in molten solder), the heads of the anode 80 and the cathode 82 are joined to each other. 80
Since the fixing portion 86 in which A and 82A are solidified is made of synthetic resin, it is softened.

Then, due to the above-mentioned residual stress, the foot portion 80
B and 82B move in the direction of arrow P in FIG. 11A, and the head portions 80A and 82A of the anode 80 and the cathode 82 move. When the head portions 80A and 82A move, the connecting portion of the bonding wire 84 separates, resulting in poor contact. Therefore, when the light emitting diode LED is made to emit light, there arises a problem that the light emitting diode LED is in a state of not emitting light (non-lighting).

Therefore, an object of the present invention is to provide an electronic component capable of preventing the contact failure by preventing the movement of the connecting portion.

[0012]

An electronic component according to the present invention comprises a plurality of leads, a connecting portion for connecting the leads, a fixing portion for fixing the connecting portion with a resin, and a protruding portion from the fixing portion. A protruding portion of the lead that is bent, and provided on the lead, after the protruding portion is bent,
A fragile portion that reduces the stress associated with bending so that the connecting portion does not move.

In the electronic component according to the present invention, for example, after bending the protruding portion of the lead of the light emitting diode, the adhesive for positioning the electronic component placed on the printed wiring board by passing through the heating furnace is cured, Alternatively, when the electronic component is dipped in molten solder for soldering to the printed wiring board, the fragile portion is deformed and the stress is reduced so that the connection portion does not move. That is, the residual stress acts on the lead due to the bending of the protruding portion, and when the resin-made fixing portion is heated in this acting state, the lead moves in the bending direction due to the residual stress. Therefore, the connection of the connecting portion may be separated, but the stress is reduced by the deformation of the weak portion and the connecting portion does not move, so that the contact failure of the connecting portion is prevented and the non-lighting of the light emitting diode is reduced.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. The first embodiment is an example in which the electronic component of the invention is a light emitting diode LED. 1 to 6, parts corresponding to those in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted. In addition, in FIG.
It is a figure which shows the state mounted in No. 6.

In the first embodiment, the fixed portion 86 is
The stopper substrate 10 as a stopper is provided on the roots 80C and 82C sides of the anode 80 and the cathode 82. As shown in FIGS. 1B and 3, the stopper substrate 10 has a substantially rectangular planar shape.

The stopper board 10 has a pair of notch-shaped elongated holes 12 formed at a position substantially in the middle of the stopper board 10 in a direction orthogonal to the longitudinal direction thereof (the arrow L direction and the R direction in FIG. 1). 14 is formed. Long holes 12,14
Have their openings 12A and 14A facing in the same direction,
Moreover, the widths of the openings 12A and 14A are slightly larger than the diameters of the foot portions 80B and 82B of the anode 80 and the cathode 82. This is the foot 8 with respect to the long holes 12, 14.
0B and 82B can be easily inserted.

Further, the long holes 12 and 14 are formed in a linear shape and are continuously formed with the same width as the width of the openings 12A and 14A. Then, the openings 12A, 14 of the long holes 12, 14
A is provided at a position corresponding to each of the foot portions 80B and 82B.

The stopper substrate 10 is formed of a synthetic resin of glass and epoxy, which is highly heat resistant and is an insulator, as a material. Here, the reason why the high heat resistance is to be strong against heat is that it is necessary to endure this high temperature because it is immersed in a high temperature solution in the manufacture of the light emitting diode LED.

The reason why the insulator is used is as follows. This is because if the stopper substrate 10 is made of a conductor, the legs 80B and 82B are connected via the stopper substrate 10 and a large current flows through the stopper substrate 10 to cause a short circuit.
That is, even if the anode 80 and the cathode 82 are connected via the stopper substrate 10, a short circuit is prevented.

A lead insertion hole 26A is formed in the printed wiring board 26, as shown in FIG. On the lower surface of the printed wiring board 26, as shown in FIG. 1B,
An annular wiring circuit conductor (land) 20 is formed on the periphery of the lead insertion hole 26A. 80 feet on this land 20
Feet 80B, 8 so that B, 82B can be soldered
Bend 2B.

Next, the light emitting diode LED of this embodiment
Will be described. As shown in FIG. 4, a pair of legs 80B and 82B of the anode 80 and the cathode 82 are integrally formed by pressing through the connecting body 16, and the pair of anode 80 and the cathode 82 are successively formed. In the example of FIG. 4, only two sets are shown.

Further, the bonding wire 84 is spot welded or the like to the head 80A of the anode 80 and the cathode 82,
Connect to 82A. The heads 80A and 82A to which the bonding wires 84 are connected are inserted into the cavity 18A of the die 18 having the shape of the fixed portion 86 of FIG. 1, and the cavity 18A of the die 18 is inserted into the cavity 18A of FIG. The resin solution (fixed portion 86) shown in (4) is injected so that the injection port 18B of the cavity 18A is slightly left (see a pair of the anode 80 and the cathode 82 on the arrow L side in FIG. 5). In this state, as shown in FIG. 5, the stopper substrate 10 is inserted (slide) above the cavity 18A to the position shown in FIG. 3 with the elongated holes 12 and 14 corresponding to the legs 80B and 82B. Then, the stopper substrate 10 is brought into a state of being floated on the liquid surface of the dissolving liquid.
The reason why the stopper substrate 10 is located on the liquid surface of the dissolving liquid and does not sink is that the surface of the dissolving liquid is slightly solidified in the time required for the inserting operation of the stopper substrate 10.

After the stopper substrate 10 is positioned on the dissolving solution, the dissolving solution is poured again, and the solution is injected until it is filled into the injection port 18B of the cavity 18A (a pair of anodes 80 on the arrow R side in FIG. 5). Cathode 82). After the predetermined time has passed and the solution is cooled and solidified, the fixed portion 86 formed
Is pulled out from the cavity 18A of the mold 18. As a result, the fixing portion 86 of the light emitting diode LED as shown in FIG. 1 is molded.

After this, the legs 80B and 82B and the connecting body 16
And are cut at a position shown by a broken line in FIG. 6 by a press not shown. Then, taping as shown in FIG. 6 is performed.
That is, the strip 22 is arranged in a state of being pulled out in a direction orthogonal to the longitudinal direction of the legs 80B and 82B, and the adhesive tape 24 is attached to the strip 22 with the legs 80B and 82B sandwiched therebetween. Further, the light emitting diode LED is mounted on the printed wiring board 26 shown in FIG. 1 by using an automatic mounting device (not shown).

This mounting is carried out by an automatic mounting device, and the foot portion 80 fixed to the band 22 by the adhesive tape 24 shown in FIG.
B and 82B are pulled out along the longitudinal direction of the legs 80B and 82B (direction of arrow S in FIG. 6) to obtain the printed wiring board 2
6 into the lead insertion hole 26A. As shown in FIG. 1A, the bottom surface 86A of the fixing portion 86 of the light emitting diode LED is mounted on the printed wiring board 2 by this automatic mounting apparatus.
Repeat until it comes into contact with the surface of 6.

Thereafter, the leg portions 80B, 82B protruding from the lead insertion hole 26A are cut to an appropriate length (for example, the length shown in FIG. 2) with a cutting tool (not shown), and the leg portions 80B, 8B are cut.
Bend 2B in the appropriate direction. For example, as shown in FIG. 1B, the foot portions 80B, 82B are pressed by pressing claws (not shown) in the longitudinal direction of the stopper substrate 10 (in FIG. 1, arrow R direction, L direction).
Bend so that it is diagonal to the direction). In this bending direction, the axial directions of the bent legs 80B and 82B are parallel, and the tips of the legs 80B and 82B face the opposite side.

The bending direction of the legs 80B and 82B is
The direction other than the direction along the longitudinal direction of the long holes 12 and 14 of the stopper substrate 10 may be, for example, a V shape. here,
The reason that the stress is applied along the bending direction of the foot portions 80B and 82B is because the stress is applied along the bending direction of the foot portions 80B and 82B.
This is because the foot portions 80B, 82B move along the longitudinal direction of the elongated holes 12, 14 along the longitudinal direction of 2, 2 and 14 and do not function as stoppers.

In the same manner as in the conventional example, other electronic parts (including multi-legged electronic parts) not shown are placed on the adhesive applied to the printed wiring board 26 by using the automatic mounting apparatus, and the inside of the heating furnace is placed. Pass through to cure the adhesive.

Then, a component that cannot be mounted by the automatic mounting apparatus is manually inserted so that its foot corresponds to the lead insertion hole. The printed wiring board 26 is previously set to 100 ° to 13 °
After holding the temperature of 0 ° for a predetermined time, the printed wiring board 26 is dipped in the molten solder for several seconds to perform soldering.

By the way, the legs 80B and 82B are bent to be plastically deformed, and this bending causes stress on the anode 80 and the cathode 82 (residual stress due to plastic deformation).
Works. Fixing part 86 in this stressed state
Is heated (specifically, passing through a heating furnace or immersion of molten solder), the fixing portion 86 made of a synthetic resin that hardens the head portions 80A and 82A softens (thermally expands), so that the foot portion. 8
0B and 82B are the direction in which stress is applied, that is, the foot 80
It moves toward the bending direction of B and 82B (see the alternate long and short dash line in FIG. 1A).

In this case, the foot portions 80B and 82B come into contact with the peripheral edges of the elongated holes 12 and 14 of the stopper substrate 10, and the foot portion 80B
Movement of B and 82B is restricted. Therefore, the heads 80A and 82A corresponding to the connecting portions of the bonding wires 84
Is restricted and the bonding wire 84 is maintained in the connected state. Therefore, according to the present embodiment, the connection of the bonding wire 84 can be reliably maintained and the contact failure can be prevented, so that the light emitting diode LED can be prevented from being unlit. That is, the number of defective light emitting diodes LED is reduced, and the number of labor for replacement and the like is reduced.

In addition to the stopper substrate 10 shown in FIG. 3, the invention is not limited to the stopper substrate 10 shown in FIG. 3 as long as the legs 80B and 82B can be inserted into the elongated holes in the process of manufacturing the light emitting diode LED. As another example of the stopper substrate, the stopper substrate 28 shown in FIG. 7 may be used. Hereinafter, the structure and the mounting method of the stopper substrate 28 shown in FIG. 7 will be briefly described.

The elongated holes 30 and 32 formed in the stopper substrate 28 shown in FIG. 7 are orthogonal to the longitudinal direction of the stopper substrate 28, and the insertion ports 30A and 32A thereof are oriented in opposite directions. The other structure is the same as that of the stopper substrate 10 shown in FIG.

When inserting the foot portions 80B and 82B into the long holes 30 and 32 of the stopper substrate 28, the foot portion 82B is inserted into the long hole 32 as shown in FIG. 7A, for example. After that, the stopper board 28 is swung in the direction in which the insertion opening 30A of the slot 30 corresponds to the foot 80B (the direction of arrow CW in FIG. 7A), and the foot 80B is inserted into the slot 30 as shown in FIG. 7B.
Insert. The other mounting processes are the same as in the example of FIG.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 8 and 9. Second
The embodiment is an example in which the electronic component of the invention is a light emitting diode LED. 8 and 9, parts corresponding to those in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, the roots 80C and 82C of the anode 80 and the cathode 82 in the fixed portion 86 are each provided with one fragile portion 34 and 36 cut out in a substantially V shape. The fragile portions 34 and 36 have the foot 8 at the tip thereof.
It is formed up to the position of substantially the axial center of 0B and 82B, and is formed on the side where the anode 80 and the cathode 82 face each other.

Other configurations and the mounting process of the light emitting diode LED on the printed wiring board 26 are performed by the stopper board 1.
The description is omitted because it is the same as the first embodiment except the process of attaching 0 and 28.

When the fixing portion 86 is heated while the foot portions 80B and 82B are stressed, the head portion 80A,
When the fixing portion 86 made of synthetic resin that hardens 82A is softened, the foot portions 80B and 82B move in the stressed direction, that is, in the bending direction of the foot portions 80B and 82B.

In this case, in the present embodiment, the fragile portion 3
As shown in FIG.
As shown in A, only the foot portions 80B and 82B on the printed wiring board 26 side move under stress from the fragile portions 34 and 36, and the fragile portions 34 and 36 move to the head portions 80A and 82A without stress. Absent. Therefore, according to the present embodiment, it is possible to reliably maintain the connection of the bonding wire 84,
Since contact failure can be prevented, non-lighting of the light emitting diode LED can be prevented.

Further, according to this embodiment, the anode 8
0, since only the notched weak portions 34 and 36 are formed in the root portions 80C and 82C of the cathode 82, it is possible to easily and easily prevent non-lighting of the light emitting diode LED and reduce the manufacturing cost. The fragile portions 34 and 36 are connected to the anode 80.
If the cathode and the cathode 82 are integrally molded during press molding, they can be manufactured more easily, and the manufacturing cost can be further reduced, as compared with a case where they are manufactured by another step (for example, cutting with a drilling machine after press molding). It can be reduced.

In the fragile portion of the present invention, the head 80
If it is formed so that stress does not act on the A and 82A sides, the shape of each foot 80 is as shown in FIG. 10, for example.
Notches 38A, 38B and 4 on both sides of B and 82B, respectively
0A and 40B may be formed. In the case of FIG. 10, the notch 38A, 38B and 40A, 40B make the notch 38
It is necessary to set so that the A, 38B and 40A, 40B portions are not easily cut.

Although not shown, the shape of the fragile portion may be bellows-like, or a plurality of small holes may be formed.
Further, only the portion corresponding to the fragile portion of the lead may be molded with a material that easily elastically deforms.

In each of the above embodiments, the electronic component of the present invention is an example of a light emitting diode LED, but the electronic component is not limited to the light emitting diode, and the connecting portion is molded with resin. If so, it can be similarly applied to electronic parts such as capacitors and resistors.

[0044]

As described above, according to the present invention, since the lead is provided with the fragile portion for reducing the stress caused by bending so that the connecting portion does not move, the movement of the connecting portion of the electronic component is prevented. Therefore, contact failure can be prevented.

[Brief description of drawings]

FIG. 1 is a view showing a mounting state of a light emitting diode according to a first embodiment of the present invention, FIG. 1A is a sectional view, and FIG. 1B is a bottom view.

FIG. 2 is a sectional view of the light emitting diode shown in FIG. 1 before mounting.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a view for explaining the manufacturing process of the light emitting diode of FIG. 2, and a sectional view showing a state in which the head is inserted into the cavity of the mold.

5 is a diagram illustrating a manufacturing process of the light emitting diode of FIG. 2, and is a cross-sectional view showing a state in which a solution is injected into a cavity and a stopper substrate is put in the state of FIG.

FIG. 6 is a view for explaining the manufacturing process of the light emitting diode of FIG. 2, and is a front view showing a state where the light emitting diode is removed from the mold and taped from the state of FIG.

FIG. 7 is a plan view showing another embodiment of the stopper substrate according to the first embodiment of the present invention, and FIGS. 7A and 7B are views showing a process of attaching the stopper substrate to the foot portion of the light emitting diode.

FIG. 8 is a view showing a mounting state of a light emitting diode according to a second embodiment of the present invention, FIG. 8A is a sectional view, and FIG. 8B is a bottom view.

9 is a cross-sectional view before mounting the light emitting diode shown in FIG.

FIG. 10 is a cross-sectional view of a light emitting diode showing another embodiment of a fragile portion according to the second embodiment of the present invention.

FIG. 11 is a diagram showing a conventional light emitting diode, FIG. 11A is a front view thereof, and FIG. 11B is a plan view thereof.

[Explanation of symbols]

 34,36 Fragile part 38A, 38B Fragile part 40A, 40B Fragile part 80 Anode (lead) 80A Head (connecting part) 80B Foot part (protruding part) 82 Cathode (lead) 82A Head part (connecting part) 82B Foot part ( Protrusion part 84 Bonding wire (connecting part) 86 Fixing part LED Light emitting diode (electronic part)

Claims (1)

[Claims] 1. A plurality of leads, a connecting portion that connects these leads, a fixing portion that fixes the connecting portion with a resin, a protruding portion of the lead that projects from the fixing portion and is bent, An electronic component, comprising: a fragile portion that is provided on a lead and that reduces stress due to bending so that the connecting portion does not move after the protruding portion is bent.