JPS6013306B2 - wire bonder - Google Patents

Description

Detailed Description of the Invention The present invention utilizes a parallelogram mechanism so that the vertical movement of the tool can always be maintained perpendicular to the workpiece regardless of variations in the height of the bonding point, and also eliminates the need for tools that are likely to occur during high-speed bonding. In order to prevent the wire from bouncing up and down, it is equipped with a spring-holding machine using a leaf spring, and the lifting movement of the tool and the gripping movement of the clamp are mechanically synchronized to ensure that the size of the ball formed at the tip of the wire is constant. The present invention relates to a wire bonder which is equipped with a clamp opening/closing mechanism to easily and reliably perform uniform and good bonding at high speed.

A tool 2 in a conventional wire bonder is fixed to one end of a tool holding arm 1 as shown in FIG. The end face of the tool 2 is momentarily pressed against the surface to be bonded by circular reciprocating motion of the tool holding arm 1 with the shaft 4 as the fulcrum.

However, in this wire bonder having a conventional structure, if there are variations in the height of the surface to be bonded, for example, the thickness of the workpiece 5, a problem arises in that uniform and good bonding cannot be performed. That is, if the central axis of the tool 2 during bonding is perpendicular to the surface of the workpiece 5', an annular impression will be formed as shown in FIG. 3A, and ideal bonding will be achieved. When the angle is not right, for example, as shown in Fig. 2, when the surface of the tool 5 is higher than the ideal position a or lower than the ideal position c, the tool end face is not evenly pressed against the work surface, and if the work surface is high, the As shown in Figure 3B, the left part is a chipped indentation, and when the work surface is low, the right part is chipped as shown in Figure 3C, which prevents good bonding. The present invention was made in order to eliminate such drawbacks, and the vertical movement of the tool 2 always acts in the vertical direction, so that the tool 2 is always perpendicular to the work surface regardless of the height of the bonding point, that is, the work surface. To provide a wire bonder that can perform ideal bonding by adjusting the wire bonding conditions.

The present invention will be explained in detail below based on the embodiments shown in FIGS. 4 to 7. A front link 8 that holds the tool holder 6 and clamp 7 that attaches the tool 2 to the lower end.
The left end of the upper link 9 is pivotally supported at the upper end by a pin 10, and the left end of the lower link holder is pivotally supported by a pin turtle 2 at the lower end of the front link 8.

The right ends of the upper link 9 and the lower link 11 are supported on the body 15 by shafts 3 and i4, respectively. The distance between pins IQ and 12 is equal to the distance between axes 13 and 14, and the distance between pin 10 and axis 13 is equal to the distance between pin turtle 2 and axis 14, so these pins 10
, 12, and the wires 3 and 4 form a parallelogram, and the front link 8 held by pins 0 and 2 forms a parallelogram.
is always moving parallel to the line connecting Nezumi 3 and i4, so the front link 8 that holds the tool 2 perpendicular to the workpiece 5 is always perpendicular to the workpiece 5 regardless of the height of the workpiece 5. I will keep it.

Therefore, the indentation of the tool 2 always becomes circular as shown in FIG. 3A, and perfect bonding can be performed in all directions.
A first bonding cam 7, a second bonding cam 18, and a clamp opening/closing cam 19 are coaxially attached to the cam 6 for moving the tool 2 up and down.

The rattan 14 has an arm 20 and a spring hanger 2.
1 is fixed to the shaft 14, and the lower link 11 and the Y-shaped bell cranks 22 and 23, which are interlocked with each other by the first bonding cam 17 and the second bonding cam 18', are attached to the shaft 14, respectively. has been done.

One ends of the bell cranks 22 and 23 are provided with rollers 24 and 25 that come into contact with the first bonding cam 17 and the second bonding cam 18, respectively, and adjustment screws 26 and 27 are screwed through the ends of the bell cranks 22 and 23, respectively. A shoulder pin 28 is fixed to the arm 20, and the shoulder pin 28 passes through a vertical hole 55 provided in the lower link 11 so that its shoulder portion 29 engages with the lower surface of the lower link 91. ing. The right end portion of a spring plate spring 30 that prevents the tool 2 from bouncing in the vertical direction is fixed to the upper surface of the lower link 11 by a screw 56. It is designed to engage with the shoulder portion 32 of the layered adjustment screw 31 screwed into the lower protrusion 57 . Spring 33 is tool 2
Its lower end is attached to the right end extending to the right from the wisteria 14 of the lower link turtle, and the upper end is attached to the adjustment screw 3 provided on the body 15. The spring 35 that always urges the tool 2 downward is used to balance the weight of the front link 8, upper link 9, lower link, etc., and its left end is closer to the right end of the upper link g. It is fixed to the upper end of a spring hanger 36 provided in an upright state, and its right end is fixed to an adjustment screw 37 provided on the body 15.

The spring 38 acts to rotate the weight 4 in a clockwise direction, and one end of the spring 38 is engaged with the spring hanger 21, and the other end is engaged with a spring hanger (not shown) provided on the body 15.

The turtle figure shows tool 2 in the bonding position (first and second
When 0 is the first bonding, the first bonding cam 17 and the roller 24 provided at one end of the bell crank 22 are in contact (with the second bonding cam 18). During the second bonding, the second bonding cam 18 and the roller 25 provided at one end of the bell crank 23 are in contact (no contact with the roller 25 provided at one end of the bell crank 23). 1 Bonding cam 17 and bell crank 22
The outer peripheries of the first bonding cam 17 and the second bonding cam 18 are shaped so that they do not come in contact with the roller 24 provided at one end, so that the first bonding portion of the workpiece 5 is By adjusting the adjustment screws 26 and 21 according to the height of the second bonding part and the second bonding part, the upper surface of the arm 20 is in contact with the tips of the adjustment screws 26 and 27, so that the arm 20 can be moved clockwise or counterclockwise. The tool 2 is rotated by interlocking the lower link 11 which is lifted by the shoulder pin 28' fixed to the arm 20.
The lower limit position can be adjusted. In order to reliably apply a predetermined pressure to the tool 2 during both the first bonding and the second bonding, bonding is performed just before the lowering limit of the tool 2, so during bonding, the shoulder 29 of the shoulder pin 28 fixed to the arm 2 A slight gap a is created between the lower link 11 and the bottom surface of the lower link 11, and the spring 33 applies a predetermined pressure to the tool 2 that is pre-adjusted by the adjustment screw 34. There is a slight gap b between the lower surface of the left end of the holding plate spring 30 and the shoulder part 32 of the shoulder adjustment screw 31.
By adjusting the shoulder adjustment screw 31 so that this occurs, the spring plate spring 30 will not press the tool 2 at all, but the tool 2 will be in the loop position after the first bonding or the second bonding. Or, when it is in the reset position (Fig. 5), this gap b disappears and the lower surface of the left end of the ZO spring plate spring 30 is at the shoulder part 3 of the shoulder adjustment screw 31.
Since the tool 2 is pressed downward to prevent the tool 2 from bouncing, high-speed and stable bonding work is possible. Figure 6 is a main side view showing the clamp mechanism, and the lever 39 and bell crank 40 for opening and closing the clamp 7 are mounted on the Z13. There are left and right adjusting screws 42 and a lock nut 43 for adjusting the amount, as well as a button 44 having a conical hole in the head.

A ball bearing 45, which is loosely attached to the shaft 14, is sandwiched between the ends of the left and right adjustment screws 42, leaving a gap c between them and one of the adjustment screws 42. bell crank 401
This is provided with a roller 46 that engages with the clamp opening/closing cam 19, and the lower left end of the bell crank 40 is provided with an adjustment screw 4.
It is designed to engage with the right end of 1. spring turtle 7
is for giving the clamp 7 a closing motion, and its upper end engages with the right end of the bell crank 40, and its lower end engages with a spring hanger 438 provided on the body 15. Fig. 7 is a view of the clamp viewed from above and shows the clamp in its closed state. , an adjustment screw 52, and a pin 53 for maintaining the relative position of the left and right claws 7a and 7b, with the right claw 7b attached below the front link 8.

A push rod 54 is held between the conical head hole of the pin 51 and the conical head hole of the button 44 provided at the lower end of the lever 39. The left and right ends of the push rod 64 are spherical, and the distance between the centers of these two spherical surfaces is equal to the distance between the pin 12 and the shaft 14.The push rod 54 is provided parallel to the line connecting the pin 12 and the shaft 14. As shown in Fig. 6, the outer peripheral shape of the clamp opening/closing cam 19 is such that a recessed part is provided in a part of the 0 circle with an inclined surface 19a from the ○ circle. is the second
This shows the state at the time of bonding. ``Since the roller 46 is riding on the same 0 circle of the clamp opening/closing cam 19, the contact between the lower left end of the bell crank 40 and the right end of the adjustment screw 4 is broken and the clamp is removed. Due to the tension of the spring 58, the left pawl 7a is turned clockwise around the lever pin 49 and opened, and the lever 39 is moved around the shaft 13 via the adjustment screw 52, pin 51, push rod 54 and button 44. Because it is turned counterclockwise, the right end of the left adjustment screw 42 and the outer diameter of the ball bearing 45 come into contact with each other, and the left end of the right adjustment screw 42 and the ball bearing 45 contact each other.
A gap c is formed between the outer diameter of the bell crank 40 and a gap d is formed between the right end of the adjusting screw 41 and the lower left end of the bell crank 40.
When the cam hammer 6 rotates from the state shown in FIG. 6, the tool 2 begins to rise. At this time, the spring 47 acts to rotate the bell crank 40 clockwise about the shaft 13, so the roller 46 is rotated by the clamping cam. According to the rotation of 19-Z, the bell crank 4 falls along the inclined surface 19a on its outer periphery.
0 rotates clockwise, the gap d between the lower left end of the bell crank 40 and the right end of the adjustment screw 41 disappears, and the lever 39
is turned clockwise, the gap c between the left end of the right adjusting screw 42 and the outer diameter of the ball bearing 405 disappears, and a gap c is created between the right end of the left adjusting screw 42 and the outer periphery of the ball bearing 405. . During this time, clockwise rotation of the lever 39 moves the left pawl 7a to the hinge pin 49 via the button 44, push rod 54L, pin 51 and adjustment screw 52.
The tackle clamp 7 is closed by turning it counterclockwise against the tension of the spring 50 around the center, but the closing timing is determined by the size of the gap d between the right end of the adjustment screw 41 and the lower left end of the bell crank 40. In other words, if the gap d is large, the number of times the clamp opening/closing cam 19 is calibrated from the position shown in FIG. 6 until the clamp 7 is closed becomes large.
Therefore, the amount of rotation of the vertical movement cams of the tool 2 fixed to the same cam shaft 16 as the clamp opening/closing cam turtle 9, that is, the first bonding cam 7 and the second bonding cam 18, increases, and the workpiece 5 of the tool 2 increases. Since the height from the tool 2 increases, the amount of protrusion of the wire 3 from the tip of the tool 2 increases. If the upper clearance d is reduced by 4 degrees, the amount of protrusion of the wire 3 from the tip of the ring 2 will also be reduced. Clamp 7
After the clamp 7 closes and grips the wire 3, the clamp 7 continues to rise together with the tool 2, tears off the wire 3 at the bonding point, and reaches the reset position. Since the gap d can be freely changed by adjusting the adjustment screw 41, the amount of protrusion of the wire 3 from the tip of the tool 2 can be adjusted at an appropriate time while the tool 2 is rising toward the reset position after the second bonding. The clamp 7 can be closed to grip the wire 3, and since the lifting movement of the tool 2 and the gripping movement of the clamp 7 are mechanically synchronized, the tool 2 is always kept constant according to the adjustment of the adjustment screw 41. Therefore, when the tool 2 rises to the reset position and squeezes the pole at the tip of the wire 3 using hydrogen flame, etc., a constant ball size can be obtained. Become.

After a ball is formed at the tip of the wire 3 protruding from the tip of the tool 2, when the first bonding cam 17, second bonding cam 18, and clamping cam 19 for vertical movement of the tool 2 rotate to the reset position. roller 4
6 rides on the same circular part of the clamp opening/closing cam 19 again, and the clamp 7 is opened. The above is the structure and operation of this embodiment. The tool of the present invention is provided at the end of the front link, which has a parallelogram-like combination on the side surface and moves up and down in the vertical direction. ``As the tool is always vertically moved up and down, even if there are vertical variations in the surface to be bonded, that is, the work surface, the tool can be positioned perpendicular to the work surface to achieve ideal bonding. There are certain effects that can be achieved.

3 Also, according to the present invention, the spring plate spring 30
The spring-holding mechanism prevents the tool 2 from bouncing during bonding, making high-speed bonding possible.Furthermore, by providing a clamp opening/closing mechanism that works with the vertical movement of the tool, the upward movement of the tool 2 is prevented. The gripping motion of the clamp 7 is mechanically synchronized to obtain a constant pole size, which is effective in achieving uniform and good bonding.

[Brief explanation of the drawing]

FIG. 1 is a schematic view of essential parts of a conventional wire bonder, FIG. 2 is an enlarged sectional view of a tool, and FIG. 3 shows the shape of an indentation made by the tool. Figures 4, 5, 6 and 7 show an embodiment of the present invention, with Figure 4 being a side view of the main part when it is in the bonding position to Figure 5 being in the reset position. FIG. 6 is a side view of the main part at a certain time, FIG. 6 is a side view of the main part showing the clamp mechanism, and FIG. 7 is a view of the clamp viewed from above. 1...
Tool holding arm, 2...tool, 3. ．．・…Wire−
, 4...axis, 5...workpiece, 6...tool holder, 7
... Clamp, 8 ... Front link, 9 ... Upper link, 10 ... Pin, 011 ... Lower link, 12
...Pin, 13, 1 Tortoise...Shaft, 15...Body, 16...
...Cam track, 17...Cam for first bonding, 18...
Second bonding cam, 19... Clamp opening/closing cam, 20... Arm, 21... Spring hanger, 22
, 23... Bell crank, 24, 25... Roller, 2
6, 27...Adjustment screw, 28...Shoulder pin, 2
9...Scrap part 30...Bounce plate spring,
39...Shoulder adjustment screw, 32...Shoulder adjustment screw
33...Spring, 34...Adjustment screw
35...Spring, 36...Spring hanger, 37...Adjustment screw, 38...Spring,
39...Lever, 40...Bell crank, 41,4
2...adjustment screw, 43...lock nut "44"
... Button, 45 ... Ball bearing, 46 ... Roller, 47 ... Spring, 48 ... Spring hanger "49 ... Hinge pin, 50 ... Spring, 51 ...
... Pin, 52 ... Adjustment screw, 53 ... Pin, 54 ... Push rod, 55 ... Vertical hole, 56 ... Screw, 57 ... Protrusion. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1 In a wire bonder, shafts 13 and 14 are provided at two points vertically spaced apart from each other on the body of the wire bonder, and a hot spring is supported by the shaft 13 at one end and has a shaft hole at the other end. A lower link 11 whose one end is supported by the shaft 14 and whose other end is provided with shaft holes at positions that maintain equal spacing between the shaft holes at both ends of the upper link 9. and pins 10 and 12 are provided between two points equal to the distance between the shafts 13 and 14, one pin 10 fits into the shaft hole of the upper link 9, and the other pin 1
A wire bonder characterized in that 2 has a front link 8 fitted into a shaft hole of a lower link 11 and a tool 2 provided on the front link 8.