JP3031060B2 - Electronic component bonding head device and electronic component bonding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding head device for an electronic component and a method for bonding an electronic component, and more particularly, to a method for easily setting a bonding load and an electronic component when a suction portion contacts the electronic component. To prevent damage.

[0002]

2. Description of the Related Art A die bonding process for mounting a die on a lead frame is performed as follows. That is, the lead frame is positioned on the transport rail, and a bond is applied to the lead frame by a dispenser or the like.
On the other hand, the electronic component cut into a predetermined shape from the wafer is pushed up by the ejector, the bonding head device is lowered, the pushed up electronic component is sucked by the suction portion of the bonding head device, and the device is raised. Pick up. Then, the electronic component is transferred to the lead frame side, the bonding head device is lowered again, the electronic components sucked by the suction portion are mounted on the lead frame, and the device is raised. As described above, the bonding head device performs the elevating operation at least twice (when picking up the electronic component pushed up by the ejector and when mounting the picked up electronic component on the lead frame) in one stroke of the die bonding process. Is going.

FIG. 8 is an exemplary view of a conventional bonding head device. In FIG. 8, LF is a lead frame, B is a bond, P is an electronic component, 110 is a supporting mechanism of the bonding head device, 120 is an upper part supported so as to be able to move up and down with respect to the supporting mechanism 110, and an electronic part is formed at a lower part. A movable mechanism having a suction part 122 for sucking the component P,
Reference numeral 30 denotes a moving unit for moving the support mechanism 110 in the XYZθ directions.

[0004] The movable mechanism 120 includes a suction nozzle 122a, a die collet 122b attached to a lower portion of the nozzle 122a, and a lifting rod 121 connected to an upper portion of the nozzle 122a.

The support mechanism 110 includes a holder 111,
An elevating rod 121 provided in the holder 111
The guide bushes 112 and 113 support the guide bushing vertically.

[0006] K is a bonding load setting spring that is attached at the upper end to the lower part of the holder 111 and at the lower end to the upper part of the nozzle 122a. As described above, in the conventional means, assuming that the pressing force by the moving means 130 moving in the XYZθ directions is constant, the bonding load for the bonding head device to press the electronic component against the lead frame is set only by the spring K. Was something.

[0007]

By the way, in the field of die bonding, large-variety, small-quantity production has been performed, and electronic components of various sizes are bonded.

Here, if the size of the electronic component is large, the contact area becomes large and a large amount of bonding is required. Therefore, it is necessary to apply a large bonding load and firmly bond. Conversely, small electronic components require a small bonding load to prevent damage to the electronic components.
As described above, when the size of the electronic component is different, an appropriate bonding load is different, and thus the setting of the bonding load is often changed.

However, if the bonding load is set only by the spring K as in the conventional means, the spring K must be replaced every time the setting is changed, and it is necessary to prepare various springs K. In addition, at the time of the replacement, it is necessary to stop the entire die bonding process, which causes a problem that the work yield is reduced.

The movable mechanism 120 is supported by the support mechanism 110 by a spring K. Then, as shown in FIG. 8B, when the holder 111 moves down to the lowest position, the following phenomenon may occur.

That is, when the holder 111 descends, an upward inertial force acts on the movable mechanism 120 due to its downward acceleration, and the spring K is in a state of being contracted from its natural length.

When the holder 111 reaches the lowermost position and stops, the upward acceleration becomes zero, and the inertia force does not act on the movable mechanism 120. Therefore, the spring K is released from the contracted state, and vibrates (expands or contracts).

As a result, the suction portion 122 located at the lower portion of the movable mechanism 120 repeatedly rises (FIG. 3C) and descends (FIG. 2B) (jumping phenomenon), thereby damaging the delicate electronic component P. There was a risk of doing.

In recent years, in order to speed up bonding, the acceleration and the inertial force have been increasing. Therefore, when the spring constant of the spring K is small, the amplitude of the vibration (expansion and contraction) increases, and the jumping phenomenon has become more remarkable.

Therefore, in the conventional means, the spring constant of the spring K is increased in order to suppress this jumping phenomenon. As described above, when the spring constant is increased, the amplitude is reduced. However, even in this case, the product of the spring constant and the amplitude (the force exerted on the electronic component P by the suction nozzle 122a) cannot be reduced, and the above-described problem that the electronic component P is easily damaged can not be solved. Did not.

FIG. 8 shows a state in which the picked-up electronic component is mounted on the lead frame during the two lifting operations of the bonding head device. When picking up the electronic component pushed up by the ejector, FIG. Have the same problems as described above.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a means that can change the setting of the bonding load without replacing the components and that is less likely to damage the electronic components.

[0018]

SUMMARY OF THE INVENTION The present invention comprises a support mechanism,
An upper part is supported so as to be able to move up and down with respect to the support mechanism, and a movable mechanism having a suction part for sucking an electronic component is provided at a lower part, based on a passive element provided in the support mechanism and a value set in the passive element based on a set value. The movable mechanism has control means for applying an external force that pushes down the support mechanism,
A bonding head device is configured.

Also, when the suction section is about to descend most,
The external force for pressing the movable mechanism against the support mechanism is reduced.

[0020]

According to the above arrangement, the external force for pushing down the movable mechanism is determined by the set value in the control means. Therefore, when changing the setting of the bonding load,
What is necessary is just to change this set value, and there is no need to replace any parts. In addition, by reducing the external force that pushes down the movable mechanism when the suction section is about to descend, the electronic component can be prevented from being damaged by preventing an excessive shock from being applied to the electronic component.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a perspective view of a bonding head apparatus and a die bonding apparatus using the apparatus according to an embodiment of the present invention, and FIG. 1B is an exploded view of the moving means (Zθ direction). FIG. 2, FIG. 2 is an assembly diagram of the bonding head device, FIG. 3 is a longitudinal sectional view of the same, FIG.
FIG. 5 is a longitudinal sectional view of the bonding head device when it is about to descend, FIG. 6 is an explanatory diagram of the operation, and FIG. 7 is a longitudinal sectional view of a bonding head device according to another embodiment.

As shown in FIGS. 1 and 2, this bonding apparatus includes a support mechanism 10, a movable mechanism 20,
Moving means 30 for moving the support mechanism 10 in the YZθ direction;
The passive element DP provided on the support mechanism 10 and the movable mechanism 20 based on the set value of the passive element DP
And a control means 40 for applying an external force for pushing down to 0.

Reference numeral 1 denotes a head unit, which has a suction unit 22 (consisting of a collet-type nozzle or the like, as will be described later) that sucks an electronic component P on the wafer W as an electronic component supply unit. LF is a substrate such as a lead frame on which the electronic component P is mounted (hereinafter simply referred to as a lead frame).

First, the moving means 30 of the support mechanism 10 will be described with reference to FIG.

Reference numeral 311 denotes a first direct motor comprising a linear motor, which has a horizontal guide 312 and a slider 313 which slides on the guide 312. The head 1 is mounted on the slider 313. Move in the horizontal direction Y. 314 is a coil provided on the guide 312, 315 and 316 are a yoke and a magnet provided on the lower surface of the slider 313. Slider 31
3 is provided with an air hole (not shown) constituting an air receiver, and slightly floats on the guide 312 to move in the lateral direction Y.

In FIG. 1B, reference numeral 321 denotes a head 1
Is a second direct motor composed of a linear motor provided in the first motor. Reference numeral 322 denotes a yoke on which the shaft 3 is inserted.
0 is concatenated. The movable mechanism 20 is supported by the support mechanism 10 so as to be able to move up and down, and a suction part 22 is provided at a lower end of the movable mechanism 20. The yoke 322 has a disk shape, and has a magnet 323 mounted on a peripheral surface thereof, and a coil 324 provided outside the magnet 323. Therefore, when the coil 324 is energized, the shaft 3 and the support mechanism 10 move up and down in the vertical direction Z, and as the support mechanism 10 moves up and down, the movable mechanism 20 and the suction part 22 at the lower end thereof become electronic components on the wafer W. The pick-up operation of P and the mounting operation of the electronic component P on the lead frame LF are performed.

Reference numeral 331 denotes a third direct motor comprising a linear motor.
3, a coil 334 is provided. A spline 4 is mounted on the shaft 3, and the spline 4 penetrates the center of the magnet 332 so as to be able to move up and down. When the coil 334 is energized, the shaft 3 and the support mechanism 10
Rotates in the θ direction about its axis.

The moving means 30 has the above-described configuration, and the operation of the moving means 30 will now be described.

The first direct motor 311 is driven to move the head unit 1 directly above the wafer W. Next, the second direct motor 321 is driven to drive the suction unit 2.
The electronic component P on the wafer W is picked up by lifting the electronic component 2 up and down. Then, the first direct motor 311
To move the head unit 1 directly above the lead frame LF, and drive the second direct motor 321 to
This electronic component P is mounted on the lead frame LF. By driving the third direct motor 331 during the above operation, the shaft 3 and the support mechanism 10 are rotated by θ,
The rotation angles of the suction unit 22 and the electronic component P are set.

Here, die bonding is performed in a clean room in order to prevent dust from adhering to the electronic component P. In the conventional means, a timing belt, a ball screw and the like are often used for the moving means. . Therefore, in the conventional means, dust is generated due to mechanical friction associated with driving of the timing belt and the like, and metal powder, belt powder, and grease powder are scattered, so that the cleanliness of the clean room is easily reduced.

On the other hand, in this means, since the timing belt, the ball screw, and the like are not used at all, the load on the direct motors 311, 321, and 331 is extremely small. The generation of dust due to friction does not occur, and the cleanliness of the clean room can be prevented from lowering.

That is, the moving means according to the present embodiment includes a head portion and a first direct motor for reciprocating the head portion in a lateral direction, and the head portion has a suction portion below. A second direct motor for moving the mechanism up and down and a third direct motor for rotating the support mechanism by θ are provided.

Note that the present means is provided for the electronic components P on the wafer W.
Is transferred to a displacement correction stage, where the displacement of the electronic component P in the XYθ directions is corrected, and then the electronic component P is picked up by the head unit 1 and mounted on a lead frame LF for die bonding. Applicable.

Next, with reference to FIG.
A detailed structure such as will be described. Now, in the support mechanism 10, reference numeral 11 denotes a horn-shaped holder.
A concave part 11a having a large diameter is formed in the center of the upper part of the upper part of the diaper. Reference numeral 11c denotes an open-to-atmosphere hole communicating with the concave portion 11a, and reference numeral 11d denotes a female screw portion provided vertically. Then, the guide bush 16 is connected to the circular hole 1.
The lifting rod 21, which will be described later, is supported by the guide bush 16 so as to be vertically movable with respect to the holder 11.

Reference numeral 12 denotes a diaphragm case mounted on the holder 11, and a circular hole 12a having a diameter larger than that of a boss 23b of a diaphragm plate 23 (described later) is formed in the center. Reference numeral 12b denotes a circular groove which is recessed on the outer peripheral side of the circular hole 12a of the case 12, and a peripheral thick portion DPa of the diaphragm DP is fitted into the circular groove 12b. Reference numeral 12c denotes a through hole opened at a position corresponding to the female screw portion 11d, and reference numeral 12d denotes a step portion which engages with the upper inner peripheral edge of the concave portion 11a of the holder 11.

Reference numeral 13 denotes a lid-shaped diaphragm case.
The case 13 rests on the case 12. 13a is a boss portion of the case 13, 13b is the same flange portion, and a circular hole 13c is opened in the center of the boss portion 13, and a through hole 13d is opened at a position corresponding to the through hole 12c of the flange portion 13b. Have been. The reduced diameter portion 15a of the pipe 15 is fitted into the circular hole 13c, and the through hole 13d,
The male screw part 14a of the bolt 14 is inserted through the male screw part 12c, and the male screw part 14a
1d.

In the movable mechanism 20, reference numeral 22 denotes a suction unit, of which 22a is a suction nozzle, which is connected to a suction system (not shown), and 22b is a die collet attached to a lower portion of the nozzle 22a. Reference numeral 21 denotes an elevating rod connected to the upper portion of the nozzle 22a, and reference numeral 21a denotes a reduced diameter portion of the rod 21.

Reference numeral 23 denotes a diaphragm plate.
a is a circular hole passing through the center of the plate 23, and the reduced diameter portion 21a of the lifting rod 21 is fitted into the circular hole 23a, and the lifting rod 21 and the diamond frame plate 23 are
Be linked. Reference numeral 23b denotes a boss of the plate 23, and a diaphragm DP, which is a passive element of the present embodiment, is in circumferential contact with the boss 23b. Reference numeral 23c denotes a flange portion of the plate 23. When the lower surface of the flange portion 23c contacts the bottom surface of the concave portion 11a, the movable mechanism 20 (diamond frame plate 23, lifting rod 21
And the lowering of the suction section 22) is restricted.

Further, DP is a diaphragm which is an example of a passive element, and a peripheral thick portion DPa of the diaphragm DP.
Is fitted into the circular groove 12b, and the holder 11 and the diaphragm cases 12, 13 are connected by the bolt 14. Then, as shown in FIG. 3, the space between the holder 11 and the diaphragm case 13 is opened to the first space S <b> 1 communicating with the flow path 15 b of the pipe 15 and to the atmosphere by the diaphragm DP in contact with the diaphragm plate 23. Into a second space S2. Then, the output (compressed air) of the control means 40 is supplied to the first space S1 via the pipe 15, and the output is controlled by a pressing force which presses the diaphragm DP.
2,...) Move up and down with respect to the support mechanism 10 (11, 12, 13).

Next, the control means 40 will be described in detail with reference to FIG. In FIG. 4, AS is a compressed air source, and V is a vacuum unit such as a vacuum pump.

RH is a high pressure setting regulator connected to the compressed air source AS, and the output pressure is 1 kg / m ²
It is constant before and after. RL is a low-pressure setting regulator using a single-acting variable actuator. The low-pressure setting regulator RL is connected to the output of the regulator RH, and controls the output pressure of the high-pressure setting regulator RH.
The pressure can be reduced to a low pressure that is finely divided into about 256 divisions. In FIG. 4, H indicates a high-pressure section and L indicates a low-pressure section.

SV1 is a first three-port solenoid switching valve for switching between high pressure and low pressure. The P port of the first switching valve SV1 is connected to the output of the low pressure setting regulator RL, and the R port is connected to the high pressure. Each is connected to the output section of the setting regulator RH. SV2 is the second 3 for switching between negative pressure and positive pressure.
Port solenoid-operated directional control valve.
The port is connected to the vacuum section V, and the R port is connected to the first switching valve SV.
1 of the second switching valve SV2.
The port communicates with the first space S1 located on the upper surface side of the diaphragm DP via the pipe 15.

Then, as shown in FIG. 4A, the first and second
When both of the switching valves SV1 and SV2 are demagnetized, the high pressure is applied to the first space S1 from the output of the high pressure setting regulator RH via the R port and the A port of the first and second switching valves SV1 and SV2. H compressed air is supplied, and the diaphragm DP is pressed downward by a large pressing force. Then, as shown in FIG. 3, the lower surface of the diaphragm plate 23 contacts the bottom surface of the concave portion 11a of the holder 11,
The suction part 22 is provided for the support mechanism 10 such as the holder 11.
It is in the lowest position.

As shown in FIG. 4 (b), when both the first and second switching valves SV1 and SV2 are excited from this state, the vacuum section V is connected to the P port and the A port of the second switching valve SV2. Through the first space S1. Then, the pressure in the space S1 decreases rapidly, and the pushing-down force also decreases rapidly.
Can freely move up and down.

Then, as shown in FIG. 4C, when the first switching valve SV1 is excited and the second switching valve SV2 is demagnetized, the output of the low pressure setting regulator RL outputs the first switching valve SV1. P port, A port and second switching valve SV
2 through the R port and the A port of the first space S1.
Communicate with Then, the low-pressure L compressed air is supplied, and the diaphragm DP is pushed downward by a relatively small pushing force. In this means, the low pressure setting regulator R
The bonding load is appropriately set according to the set value of L (see FIG. 5).

The first embodiment has the above-described configuration. Next, a bonding method using this bonding head device will be described with reference to FIG. In FIG. 6, the horizontal axis is time t. The vertical axis represents the height from the upper surface of the lead frame LF to the lower surface of the electronic component P in FIG. 6 (a), the speed of the movable part 20 in FIG. 6 (b), and the switching in FIGS. 6 (c) and (d). Excitation of valves SV1 and SV2
In the demagnetized state, the pressure in the first space S1 (proportional to the pressing force by the diaphragm DP) is shown in FIG.

At times t0 to t1, the first and second
Demagnetize both of the switching valves SV1 and SV2 of
The moving means 30 is driven (see FIG. 1) while maintaining the pressure in 1 at the high pressure H, and the support mechanism 10 and the movable mechanism 20 are lowered at a high speed. In this state, as shown in FIG.
Since the electronic component P sucked by the suction portion 22 is located significantly above the lead frame LF, there is no risk of breakage even when the electronic component P is lowered at a high speed, and the lower surface of the diaphragm plate 23 is pressed against the bottom surface of the concave portion 11a. Therefore, the movable mechanism 20 such as the suction unit 22 descends integrally with the support mechanism 10 such as the holder 11.

Next, between times t1 and t2, the first and second
Are excited, the space S1 is communicated with the vacuum portion V, and the pressure and the pressing force are rapidly reduced from the high pressure H state. The communication with the vacuum portion V is performed in order to rapidly reduce the pressure in the space S1 and improve the response speed.

Next, from time t2 to t3, only the second switching valve SV2 is demagnetized, and the space S1 is maintained at the low pressure L.
Here, as shown in FIG. 5, at time t3, the electronic component P is grounded to the lead frame LF. At this time, the electronic component P
And the suction part 22 receives a reaction force from the lead frame LF. However, since the pressure in the space S1 is low,
The external force pressing the movable mechanism 20 against the support mechanism 10 is weakened. Therefore, the movable mechanism 20 can slightly rise with respect to the support mechanism 10. Therefore, the reaction force is small and smoothly absorbed, and the electronic component P can be gently grounded to the lead frame LF.

Therefore, after the electronic component P is grounded to the lead frame LF as in the conventional means using only the spring K, the suction portion 22 vibrates vigorously up and down (jumping phenomenon) to damage the electronic component P. Never.

Next, from time t3 to t4, FIG.
As shown by the solid line, the pressure in the space S1 is maintained at a low pressure L,
Alternatively, if the bonding load is insufficient, the low-pressure setting regulator RL may be driven to gradually increase the low-pressure side pressure (see the broken line). Thereby, the electronic component P can be firmly bonded to the lead frame LF.

Then, from time t4 to t5 to t6, the first and second switching valves SV1 and SV2 are demagnetized, the pressure in the space S1 is maintained at a high pressure H, the moving means 30 is driven, and the supporting mechanism 10 and The movable mechanism 20 is raised.

FIG. 7 is a longitudinal sectional view of a bonding head device according to another embodiment. In this example, the passive element DPX is a plate 23X formed of an electromagnet 29 and a magnetic material. The control means is controlled by the electromagnet 29
Is a control means 50 for controlling the excitation state.

Then, the moving means 30 is driven, and the electronic component P sucked by the suction section 22 is moved to the lead frame L.
When the grounding is to be performed, the control means 50 is driven to make the plate 23X and the electromagnet 29 have the same polarity,
X and the electromagnet 29 are repelled. Thereby, the electronic component P
In this case, the effect of the reaction force received from the lead frame LF is reduced so that the electronic component P is not damaged. After the electronic component P is gently grounded to the lead frame LF, the control means 50 makes the plate 23X and the electromagnet 29 have different polarities so that a sufficient bonding load can be obtained.

The passive element of the present means is not limited to the diaphragm DP, the electromagnet 29 and the like, but may be variously conceived, for example, a combination of a diaphragm and a spring for biasing the diaphragm.

[0057]

According to the present invention, there is provided a support mechanism, and a movable mechanism having an upper part supported up and down with respect to the support mechanism and having a suction part at a lower part for sucking an electronic component. The bonding head device includes a passive element and control means for applying an external force that pushes down the movable mechanism to the support mechanism based on a set value of the passive element. Therefore, by changing the setting in the control means, it is possible to smoothly change the bonding load without replacing parts. Also, by reducing the external force when the suction section is about to descend,
Shock applied to the electronic component can be reduced, and damage to the electronic component can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a bonding apparatus according to the present invention.

FIG. 2 is an assembly view of the bonding head device according to the present invention.

FIG. 3 is a longitudinal sectional view according to the present invention.

FIG. 4 is a circuit diagram of control means according to the present invention.

FIG. 5 is a vertical cross-sectional view according to the present invention when trying to descend the lowest position.

FIG. 6 is an operation explanatory diagram according to the present invention.

FIG. 7 is a longitudinal sectional view according to the present invention.

FIG. 8 is a longitudinal sectional view of a conventional means.

[Explanation of symbols]

 DP passive element DPX passive element P electronic component 10 support mechanism 20 movable mechanism 22 suction unit 40 control means 50 control means

Claims (2)

(57) [Claims] 1. A bonding head device comprising: a support mechanism; and a movable mechanism having an upper portion supported to be movable up and down with respect to the support mechanism and having a suction portion at a lower portion for sucking an electronic component. An electronic component bonding head device comprising: a passive element to be used; and control means for applying an external force to push down the movable mechanism to the support mechanism based on a set value of the passive element. 2. The bonding of an electronic component according to claim 1, wherein, when bonding is performed by the bonding head device according to claim 1, an external force that pushes a movable mechanism to a support mechanism is weakened when the suction unit is about to descend. Method.