JP3145221B2 - Frame clamp device for lead frame welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame clamping device for holding a lead frame in a lead frame welding machine for spot welding with light emitting side and light receiving side lead frames such as an optical coupling element being opposed to each other.

[0002]

2. Description of the Related Art Generally, in a lead frame welding machine for spot welding a lead frame of an optical coupling device, an upper electrode 1 and a lower electrode 2 are connected to both lead frames 3, 4 as shown in FIG. As shown in FIG. 7 (B), the lower electrode 2 rises from the standby position in a state separated from the
It contacts the light emitting side lead frame 3. And FIG.
As shown in (C), the upper electrode 1 descends and comes into contact with the light-receiving-side lead frame 4, and the lead frames 3 and 4
The current flows while being pressurized by the two lead frames 3,
4 is spot-welded.

At this time, a spark is generated, or the upper electrode 1 bites into the light receiving side lead frame 4 as shown in FIG. 7D, so that the light receiving side lead frame 4 sticks up when the upper electrode 1 separates. Leave on the way. As a result, the lead frames 3 and 4 vibrate.

A light emitting element 5 and a light receiving element 6 are mounted on the lead frames 3 and 4 as shown in FIG. As shown in FIGS. 8B and 8C, there is a problem that the Au wire 7 is deformed by vibration or the Au wire 7 is broken. A frame clamp device is used to prevent these.

As a lead frame clamping method, there is a method of clamping a place distant from the spot welding position, or a method of clamping the entire lead frame but not holding down only the spot welding position.

(Prior art 1) In the former method, FIG.
0, the light emitting side lead frame 3 is placed on the rail 8 on which the light emitting side and light receiving side lead frames 3 and 4 are placed facing each other so as to enter the positioning pins 9a, and then the light receiving side lead frame 4 is placed on the positioning pins 9b. And put it in.

Next, when the claw clamp cylinder 10 is operated, the rod 11 of the claw clamp cylinder 10 moves in the direction of arrow A as shown in FIG. FIG. 9, FIG.
As shown at 10, the intermediate portions between the joints 14 of the lead frames 3 and 4 are pressed by the frame pressing claws 13 from both right and left sides of the rail 8.

Then, the joint 1 of the lead frames 3 and 4
In this configuration, the upper and lower electrodes 1 and 2 of the spot welding device are in contact with the lead frame 4 and the lead frames 3 and 4 are joined.

9 to 11, reference numeral 15 denotes a presser pawl holder, 16 denotes a pawl clamp arm, 17 denotes a pawl clamp cylinder auxiliary spring, and 18 denotes a clamp jig.

(Prior art 2) In the latter method, FIG.
13, when both lead frames 3 and 4 are placed on the rail 19 and the clamping cylinder 20 is operated, the clamp plate 21 moves in the direction of arrow C as shown in FIG.
As shown in FIG. 13, the entire lead frames 3, 4 are pressed by the clamp plates 21 on both the left and right sides of the rail 19. However, the positions of the positioning pins 9a and 9b are not pressed because they are notched.

Then, the joint 1 of the lead frames 3 and 4
In this configuration, the upper and lower electrodes 1 and 2 of the spot welding device are in contact with the lead frame 4 and the lead frames 3 and 4 are joined.

In FIGS. 12 to 14, reference numeral 22 denotes a clamp holder, reference numeral 23 denotes a spill vertical bearing, reference numeral 24 denotes a block alignment jig, reference numeral 25 denotes a jig support, and reference numeral 26 denotes a connection plate.

[0013]

However, the frame clamping device of the prior art 1 uses the principle of leverage to press a place away from the joint 14 of the lead frames 3 and 4 with the frame pressing claws 13. Further, when mounting the lead frames 3 and 4, it is necessary to move the frame pressing claws 13 to a position where the frame pressing claws 13 do not contact the lead frames 3 and 4, so that the length of the frame pressing claws 13 cannot be increased. Only the outer ends of 3, 4 are pressed. Therefore, it is not possible to prevent the vibration that occurs at the time of sparking and when the upper electrode 1 separates.

In the prior art 2, the lead frames 3, 4 are pressed by the clamp plate 21, but the positioning pins 9a, 9
Since the clamp plate 21 is cut off at the location where b is located, the vicinity of the joint portion 14 is not pressed.

Further, since the clamp plate 21 is long and is held only by its own weight, the lead frame 3,
4 cannot be pressed uniformly. For this reason, it is impossible to prevent the Au wire 7 from being deformed or cut due to vibration.

In order to solve this problem, a method of reducing the welding current at the time of welding has been employed. However, in this method, the welding strength is weakened, and the joining portions of the lead frames 3 and 4 are reduced at a later step. 14 sometimes left.

In view of the above, it is an object of the present invention to provide a frame clamp device for a lead frame welding machine that can prevent vibration during welding without reducing welding strength.

[0018]

As shown in FIGS. 1 and 2, a means for solving the problem according to the present invention comprises a connecting portion 34 in which one lead frame 31 and the other lead frame 32 are arranged to face each other.
In the lead frame welding machine for spot welding, a mounting table 33 on which both the lead frames 31, 32 are mounted.
Positioning pins 36a, 36b which are erected near the joint 34 on the mounting table 33 and penetrate through the positioning holes 35a, 35b of the lead frame;
A frame pressing member 38 having a hole 37 through which the hole 6b is inserted and pressing the vicinity of the joint portion 34, an urging means 39 for pressing the frame pressing member 38 in the pressing direction, and moving the frame pressing member 38 vertically and horizontally. A moving means 40 is provided, and a vibration isolating member 43 is attached to a contact surface of the frame pressing member 38 with the lead frames 31 and 32.

[0019]

In the above-mentioned means for solving the problems, the lead frame 3
When spot welding is performed by disposing the first and second opposed parts 32 and 32, the positioning pins 36a and 36b of the rail 33 are passed through the positioning holes 35a and 35b of the lead frames 31 and 32,
The lead frames 31 and 32 are mounted. Then, the two lead frames 31 and 32 are arranged so that the joint portions 34 of the lead frames 31 and 32 overlap.

Next, when the moving means 40 is operated, the frame holding member 38 moves up and down and horizontally, and the positioning pins 36a and 36b are inserted into the holes 37 of the frame holding member 38.

The anti-vibration member 43 is connected to the lead frame 3.
1 and 32, which presses the vicinity of the joint 34 to prevent vibration during spot welding and presses the lead frames 31, 32 in the pressing direction by the urging means 39.
When the lead frame 55 is separated, the lead frames 31 and 32 do not lift.

[0022]

FIG. 1 is a side view of a frame clamp device of a lead frame welding machine showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a side view of the frame clamp device before clamping.

As shown in FIGS. 1 to 3, a frame clamping device of a lead frame welding machine for an optical coupling element according to this embodiment includes a rail 33 on which a light emitting side lead frame 31 and a light receiving side lead frame 32 are placed. Positioning pins 36 erected near the upper joint 34 and penetrating the positioning holes 35a, 35b of the lead frames 31, 32.
a, 36b, a frame pressing claw 38 having a hole 37 through which the positioning pins 36a, 36b are inserted, and pressing the vicinity of the joint 34; an urging means 39 for pressing the frame pressing claw 38 in the pressing direction; A moving means 40 for vertically and horizontally moving the frame holding claw 38 is provided.

The frame holding claws 38 are formed in a crank shape having a rectangular cross section, and are mounted at equal intervals on a holder mounting plate 42 via a holding claw holder 41. And it is provided symmetrically across the rail 33,
With a total of eight frame holding claws 38, the lead frame 31,
You are holding 32.

The contact surfaces of the frame pressing claws 38 with the lead frames 31 and 32 are
The rail 33 is formed flat so as to press from the vicinity of the joining portion 34 to the vicinity of the outer end, and the vicinity of the outer end of the rail 33 is cut out in a substantially U-shape.

A rubber vibration isolating member 43 is attached to the end of the contact surface of the frame pressing claw 38 with the lead frames 31 and 32, and when the frame pressing claw 38 presses the lead frames 31 and 32, Lead frame 3
1, 32.

The holder mounting plate 42 is supported by an L-shaped claw moving plate 44 via a claw vertical linear guide 45 so as to be vertically movable.

The claw moving plate 44 is fixed to a claw moving LM guide 46, and the claw moving LM guide 46 is supported on a table 47 so as to be horizontally movable.

The urging means 39 includes a holder mounting plate 42
The holder mounting plate 42 is always urged downward by a spring provided between the holder mounting plate 42 and the claw moving plate 44.

The moving means 40 includes a frame holding claw 38
And a claw moving cylinder 49 for horizontally moving the frame holding claw 38.

The claw vertical motor 48 is attached to the claw moving plate 44, and a claw vertical cam 51 provided at the end of the motor shaft 50 is in contact with a claw vertical bearing 52 provided on the holder mounting plate 42. The operation of the claw vertical motor 48 causes the holder mounting plate 42 to move up and down along the claw moving plate 44 via the claw vertical cam 51.

The claw moving cylinder 49 includes a table 47
The claw moving plate 44 attached on the top and fixed to the tip of the rod shaft 53 is moved to the table 4 via the claw moving LM guide 46.
7 to move horizontally.

The moving means 40 includes a switch for stopping the claw vertical motor 48 when the frame pressing claw 38 reaches the raised position from the initial position and operating the claw moving cylinder 49, and a horizontal movement from the raised position. When the position is reached, the pawl moving cylinder 49 is stopped, and the pawl vertical motor 48 is stopped.
And a switch for stopping the claw vertical motor 48 when the pressing position is reached from the horizontal movement position.

1 and 3, reference numeral 54 denotes an upper electrode of a spot welding apparatus, 55 denotes a lower electrode, 56 denotes a clamp jig, 57
Is a jig mounting plate, 58 is a jig vertical bearing, 59 is a jig vertical cam, and 60 is a jig vertical LM guide.

In the above configuration, when the light emitting side lead frame 31 and the light receiving side lead frame 32 are spot-welded while facing each other, first, the light emitting side lead frame 31
The light emitting side lead frame 31 is placed on the positioning hole 35a through the positioning pin 36a on one side of the rail 33. The other positioning pin 36b of the rail 33 is inserted into the positioning hole 35b of the light receiving side lead frame 32.
And the light-receiving-side lead frame 32 is placed thereon, and is arranged so that the joint portions 34 of the two lead frames 31 and 32 overlap.

Next, when the left and right claw vertical motors 48 are operated, the right and left frame pressing claws 38 are driven by the claw vertical cams 51.
Goes up. When the frame holding claw 38 reaches the raised position, the claw vertical motor 48 stops, and the left and right claw moving cylinders 49 operate to move the frame holding claw 38 horizontally toward the center.

Then, the frame holding claw 38 is inserted into the hole 37 of the frame holding claw and the positioning pins 36a, 3 on the rail 33.
When reaching the horizontal movement position where 6b coincides, the pawl movement cylinder 35 stops.

Thereafter, the claw vertical motor 48 operates to lower the frame holding claw 38 to the holding position, the positioning pins 36a and 36b are inserted into the holes 37 of the frame holding claw 38, and the vibration isolating member 43 is connected to the lead frames 31, 32. And presses the vicinity of the joint portion 34. At this time, the frame pressing claws 38 are pressed by a total of four springs 39 provided between the holder mounting plate 42 and the claw moving plate 44.

Then, the lower electrode 55 of the spot welding device rises and comes into contact with the light emitting side lead frame 31, and the upper electrode 5
The spot welding is started when 4 descends and comes into contact with the light receiving side lead frame 32. When the spot welding of the first joint 34 is completed, the lead frames 31 and 32 move by the movement of the table 47, and the joints 34 are sequentially welded from the near side.

At this time, the lower electrode 55 of the spot welding device is used.
4A requires a stroke of 75 mm to the light emitting side lead frame 31 as shown in FIG. 4A, so that the welding tact time becomes slow.

This distance is longer than the stroke of the lower electrode 55 of the conventional frame clamp device shown in FIGS. 4B and 4C (40 mm in the prior art 1 and 5 mm in the prior art 2). In order to shorten the stroke, the following measures were taken.

The cylinder for moving the lower electrode 55 up and down is
A two-stage stroke cylinder 61 as shown in FIG. 5 was used.

The two-stage stroke cylinder 61 is similar to that shown in FIG.
When the first stroke cylinder 62 is operated from the lowermost position of (A), it moves to the standby position of FIG. 5B, and when the second stroke cylinder 63 is operated, it moves to the welding position of FIG. 5C. I do.

When the spot welding is started, first, the first stroke cylinder 62 and the second stroke cylinder 63 are simultaneously operated. Then, the lower electrode 55 is
The first joint 34 is welded by rising 75 mm from the lowermost position shown in FIG. 6A to the welding position shown in FIG.

When the first welding is completed, the second stroke cylinder 63 is actuated, and as shown in FIG.
5 descends 25 mm and moves to the standby position. Then, the lead frame 3 is moved from the standby position to the next joint 34.
The first and second cylinders move to operate the second stroke cylinder 63, so that the lower electrode 55 rises by 25 mm to weld the joint 34.

Similarly, the second stroke cylinder 63
Are operated to sequentially weld the joints 34. When the welding of the last joint portion 34 is completed, the first stroke cylinder 62 and the second stroke cylinder 63 are simultaneously operated, and the lower electrode 55 is lowered to the lowest position as shown in FIG. The welding operation is completed.

As described above, when welding the plurality of joints 34 provided on the lead frames 31 and 32, since the two-stage stroke cylinder 63 is used, it is not necessary to move the lower electrode 55 by 75 mm each time. 2 after the second
It only needs to be moved by 5 mm. Therefore, the moving time of the lower electrode 55 is reduced, and spot welding can be performed in the same time as in the related art.

When welding the joints 34 of the lead frames 31, 32, as shown in FIG. 1, a frame pressing claw 38 provided with an anti-vibration member 43 near the joints 34 is used.
Since the lead frames 31 and 32 are pressed, vibration due to spark during welding is prevented. And since it clamps firmly with the spring 39, the upper electrode 54 does not stick to the light receiving side lead frame 32 after welding, and does not lift. Therefore, the wire-bonded Au
Deformation and cutting of the line can be prevented.

Since vibration during welding is suppressed,
A large amount of current can be passed during welding, and welding strength is increased. Therefore, a defect such as separation of the joint portion 34 of the lead frames 31 and 32 in a later process does not occur, and stable production can be secured.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention.

For example, instead of the claw vertical motor 48 for vertically moving the frame pressing claw 38, a cylinder may be used to directly attach the frame pressing claw 38 to the frame pressing claw 38 and perform vertical movement and pressing of the lead frame by the cylinder.

[0052]

As is apparent from the above description, according to the present invention, the frame holding member provided with the vibration isolating member allows
Since the vicinity of the joint of the lead frame is held down, vibration due to spark during welding can be prevented. Since the pressing means presses the lead frame in the holding direction, the lead frame does not stick together and is lifted after welding, so that deformation and cutting of the wire-bonded Au wire can be prevented.

Further, since vibration during welding is suppressed, a large amount of current can be flowed during welding, and welding strength is increased. Therefore, there is an excellent effect that troubles in the post-process are eliminated and stable production can be secured.

[Brief description of the drawings]

FIG. 1 is a side view of a frame clamping device of a lead frame welding machine showing one embodiment of the present invention.

FIG. 2 is a plan view of a frame clamp device.

FIG. 3 is a side view of the frame clamping device before clamping.

FIG. 4A is a diagram showing the position of a lower electrode of the present invention,
(B) is a diagram showing the position of the lower electrode of the prior art 1, and (C) is a diagram showing the position of the lower electrode of the prior art 2.

5A is a diagram showing a two-stage stroke cylinder at a lowermost position, FIG. 5B is a diagram showing a two-stage stroke cylinder at a standby position, and FIG. 5C is a diagram showing two stages at a welding position; Diagram showing stroke cylinder

FIG. 6A is a diagram showing a lower electrode at a lowermost position;
(B) is a diagram showing the lower electrode at the welding position, and (C) is a diagram showing the lower electrode at the standby position.

7A is a diagram showing the upper and lower electrodes of the spot welding apparatus at the standby position, FIG. 7B is a diagram showing the lower electrode in contact with the light emitting side lead frame, and FIG. The figure which shows an electrode, (D) is the figure which the upper electrode after welding cut into the light receiving side lead frame.

8A is a diagram when a light receiving / emitting element is mounted on a lead frame and arranged to face each other, FIG. 8B is a diagram when the Au wire is deformed, and FIG. 8C is a diagram when the Au wire is broken.

FIG. 9 is a side view of a frame clamp device according to the related art 1.

FIG. 10 is a plan view of the same frame clamp device.

FIG. 11 is a side view of the frame clamp device before the clamp.

FIG. 12 is a side view of a frame clamp device according to the related art 2.

FIG. 13 is a plan view of the same frame clamp device.

FIG. 14 is a side view of the frame clamp device before clamping.

[Explanation of symbols]

 REFERENCE SIGNS LIST 31 light emitting side lead frame 32 light receiving side lead frame 33 mounting table 34 joint 35 a, 35 b positioning hole 36 a, 36 b positioning pin 37 hole 38 frame pressing member 39 urging means 40 moving means 43 vibration damping member

Claims (1)

(57) [Claims] 1. A lead frame welding machine for spot-welding a joint by arranging one lead frame and the other lead frame to face each other, and a mounting table on which the two lead frames are mounted, and a joint on the mounting table. A positioning pin that stands upright and penetrates a positioning hole of the lead frame; a frame pressing member that has a hole through which the positioning pin is inserted and presses the vicinity of the joint; and a bias that presses the frame pressing member in the pressing direction. Means for moving the frame holding member up and down and horizontally, and a vibration isolating member attached to a contact surface of the frame holding member with the lead frame. Clamping device.