JPH05326580A - Bonding head device for electronic component and bonding method for electronic component - Google Patents

Abstract

PURPOSE:To provide a means which can change the setting of bonding load without exchanging a component and besides which is hard to break an electronic component. CONSTITUTION:A bonding head device is constituted, being equipped with a supporting mechanism 10 and a moving mechanism 20, whose top is supported capably of lifting up and down to this support mechanism 10 and besides which has a suction part 22 for sucking an electronic component P at the bottom, and having a passive element DP, which is provided for the support mechanism 10, and, in this passive element DP, a control means 40 which applies external force to lifting up or lowering the moving mechanism 20 to the support mechanism 10, based on the set value.

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 electronic parts and a method for bonding electronic parts, and more particularly, to facilitating the setting of a bonding load and, when the suction part comes into contact with an electronic part, the electronic part. Related to the means 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, an electronic component cut into a predetermined shape from the wafer is pushed up by an ejector, the bonding head device is lowered, the pushed up electronic component is sucked by the suction part of the bonding head device, and this device is raised. To pick up. Then, it 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 lifting 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.

Here, FIG. 8 is an illustration 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 this supporting mechanism 110, and an electronic part is provided on the lower part. A movable mechanism having a suction portion 122 for sucking the component P, 1
Reference numeral 30 is a moving means for moving the support mechanism 110 in the XYZθ directions.

The movable mechanism 120 is composed of a suction nozzle 122a, a die collet 122b attached to the lower portion of the nozzle 122a, and an elevating rod 121 connected to the upper portion of the nozzle 122a.

The support mechanism 110 includes a holder 111,
Elevating rod 121 provided in this holder 111
It is composed of guide bushes 112 and 113 for supporting the up and down freely.

K is a bonding load setting spring whose upper end is attached to the lower part of the holder 111 and whose lower end is attached to the upper part of the nozzle 122a. Thus, in the conventional means, assuming that the pushing-down 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. It was something.

[0007]

By the way, in the field of die bonding, a wide variety of products have been produced in small quantities, and various sizes of electronic components are bonded.

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 to firmly bond. Conversely, small electronic components require a small bonding load to prevent damage to the electronic components.
When the size of the electronic component is different, the appropriate bonding load is different. Therefore, 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 only necessary to prepare various springs K. In addition, it is necessary to stop the entire die bonding process at the time of replacement, so that there is a problem that 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 descends to reach the most descended position, the following phenomenon may occur.

That is, when the holder 111 descends, its downward acceleration causes an upward inertial force to act on the movable mechanism 120, so that the spring K is in a state of contracting less than its natural length.

When the holder 111 reaches the lowest position and stops, the upward acceleration becomes 0, and the inertial force does not act on the movable mechanism 120. Therefore, the spring K is released from the contracted state and vibrates (expands and contracts).

As a result, the suction portion 122 located under the movable mechanism 120 repeatedly rises ((c) in the figure) and descends ((b) in the figure) (jumping phenomenon) to damage the delicate electronic component P. There was a risk of

In recent years, the acceleration and inertial force have become larger and larger in order to increase the bonding speed. Therefore, when the spring constant of the spring K is small, the amplitude of the vibration (expansion and contraction) becomes large, and the jumping phenomenon becomes more remarkable.

Therefore, in the conventional means, the spring constant of the spring K is increased in order to suppress this jumping phenomenon. Thus, the larger the spring constant, the smaller the amplitude. However, even in this case, the product of the spring constant and the amplitude (the force exerted by the suction nozzle 122a on the electronic component P) cannot be reduced, and the above-mentioned problem that the electronic component P is easily damaged cannot be solved. There wasn't.

FIG. 8 shows a state in which the picked-up electronic component is mounted on the lead frame in the above-described two raising / lowering operations of the bonding head device. When picking up the electronic component pushed up by the ejector, However, there is a problem similar to the above.

Therefore, an object of the present invention is to provide a means capable of changing the setting of the bonding load without exchanging the parts, and moreover, not easily damaging the electronic parts.

[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 this support mechanism, and a lower part is provided with a movable mechanism having an adsorption part for adsorbing electronic parts. Based on a passive element provided in the support mechanism and a set value for this passive element. A control means for applying an external force that pushes down the movable mechanism with respect to the support mechanism,
A bonding head device is configured.

Further, when the suction section is going to descend to the maximum,
The external force that presses the movable mechanism against the support mechanism is weakened.

[0020]

According to the above construction, 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 bonding load,
It suffices to change this set value, and there is no need to replace any part. Moreover, when the suction part is about to descend, the external force that pushes down the movable mechanism is reduced, so that an excessive shock is not applied to the electronic component, and damage to the electronic component can be prevented.

[0021]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 (a) is a perspective view of a bonding head device according to an embodiment of the present invention and a die bonding device using this device, and FIG. 1 (b) is an exploded view of the main part of the moving means (Z.theta. Direction). 2 is an assembly view of the bonding head device, FIG. 3 is a longitudinal sectional view of the same, and FIG. 4 is a circuit diagram of a control means.
5 is a vertical sectional view of the same bonding head device when it is about to descend to the lowest position, FIG. 6 is an explanatory view of the same operation, and FIG. 7 is a vertical sectional view of a bonding head device according to another embodiment.

Now, as shown in FIGS. 1 and 2, in addition to the support mechanism 10 and the movable mechanism 20, this bonding apparatus is
Moving means 30 for moving the support mechanism 10 in the YZθ directions,
The passive element DP provided on the support mechanism 10 and the movable mechanism 20 based on the set value for the passive element DP are attached to the support mechanism 1
The control means 40 for applying an external force to push down to 0.

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

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 which is a linear motor and has a horizontal guide 312 and a slider 313 which slides on the guide 312. The head section 1 is mounted on the slider 313. Move in the lateral direction Y. Reference numeral 314 is a coil provided on the guide 312, and reference numerals 315 and 316 are a yoke and a magnet provided on the lower surface of the slider 313. Slider 31
3 has an air hole (not shown) forming an air receiver, which slightly floats above the guide 312 and moves in the lateral direction Y.

In FIG. 1B, reference numeral 321 denotes the head unit 1.
2 is a second direct motor including a linear motor provided in the. Reference numeral 322 is a yoke in which the shaft 3 is inserted and attached.
0s are concatenated. The movable mechanism 20 is supported by the support mechanism 10 so that the movable mechanism 20 can move up and down, and a suction portion 22 is provided at the lower end of the movable mechanism 20. The yoke 322 has a disk shape, a magnet 323 is attached to the peripheral surface thereof, and a coil 324 is 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 portion 22 at the lower end portion of the movable mechanism 20 are electronic components on the wafer W. The pickup operation of P and the mounting operation of the electronic component P on the lead frame LF are performed.

Reference numeral 331 is a third direct motor composed of a linear motor, and includes a magnet 332 and a core 33.
3, a coil 334 is provided. A spline 4 is attached to the shaft 3, and the spline 4 penetrates the center of the magnet 332 in a vertically movable manner. When the coil 334 is energized, the shaft 3 and the support mechanism 10
Rotates about its axis in the θ direction.

The moving means 30 is constructed as described above, and the operation of the moving means 30 will be described below.

The first direct motor 311 is driven to move the head unit 1 right above the wafer W. Then, the second direct motor 321 is driven to drive the suction unit 2
2 is moved up and down to pick up the electronic component P on the wafer W by suction. Then, the first direct motor 311
Is driven to move the head unit 1 directly above the lead frame LF, and the second direct motor 321 is driven,
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, etc. are often used as the moving means. .. Therefore, in the conventional means, dust is generated due to mechanical friction accompanying the driving of the timing belt and the like, and the metal powder, the belt powder, and the grease powder are scattered, and the cleanliness of the clean room is likely to deteriorate.

On the other hand, in this means, since the timing belt, the ball screw, etc. are not used at all, the load on the direct motors 311, 321, 331 is extremely small, and not only the operation speed can be increased, but also the mechanical operation is possible. It is possible to prevent dust from being generated due to friction and prevent the cleanliness of the clean room from deteriorating.

That is, the moving means according to the present embodiment comprises a head portion and a first direct motor for laterally reciprocating the head portion, and the head portion has a suction portion below. A second direct motor that moves the mechanism up and down and a third direct motor that rotates the support mechanism by θ are provided.

This means is used for the electronic parts P on the wafer W.
Is also mounted on a misalignment correction stage to correct the misalignment of the electronic component P in the XYθ directions, and then the head part 1 picks up the electronic component P and mounts it on the lead frame LF. Applicable.

Next, referring to FIG. 2, the support mechanism 10 will be described.
The detailed structure such as is explained. In the support mechanism 10, 11 is a mortar-shaped holder.
A large-diameter recess 11a is provided in the center of the upper part of the above, and a circular hole 11b having a smaller diameter than the above-mentioned recess 11 is continuously provided coaxially with the recess 11a. Further, 11c is an atmosphere opening hole communicating with the recess 11a, and 11d is a female screw portion provided vertically. Then, the guide bush 16 has the circular hole 1
An elevating rod 21 which will be described later and which is fitted into 1b is supported by the guide bush 16 so as to be elevatable 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 portion 23b of the diaphragm plate 23 (described later) is opened in the center. Reference numeral 12b denotes a circular groove provided on the outer peripheral side of the circular hole 12a of the case 12, and the peripheral wall thickness portion DPa of the diaphragm DP is fitted into the circular groove 12b. Reference numeral 12c is a through hole formed at a position corresponding to the female screw portion 11d, and 12d is a step portion that engages with an upper portion of the inner peripheral edge of the recess 11a of the holder 11.

13 is a lid-shaped diaphragm case,
The case 13 is placed on the case 12. 13a is a boss portion of the case 13, 13b is a flange portion thereof, 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. Has been done. The reduced diameter portion 15a of the pipe 15 is fitted into the circular hole 13c, and the through hole 13d,
The male screw portion 14a of the bolt 14 is inserted into the bolt 12c, and the male screw portion 14a is inserted into the female screw portion 1 of the holder 11.
It is adapted to be screwed into 1d.

In the movable mechanism 20, 22 is a suction portion, 22a of which is a suction nozzle, which is connected to a suction system (not shown), and 22b is a die collet mounted below the nozzle 22a. Reference numeral 21 is a lifting rod connected to the upper portion of the nozzle 22a, and 21a is a reduced diameter portion of the rod 21.

23 is a diaphragm plate,
a is a circular hole penetrating the center of the plate 23. 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 connected. Reference numeral 23b denotes a boss portion of the plate 23, and the diaphragm DP, which is a passive element of the present embodiment, makes a circumferential contact with the boss portion 23b. Reference numeral 23c is a flange portion of the plate 23, and the lower surface of the flange portion 23c is in contact with the bottom surface of the recess 11a, whereby the movable mechanism 20 (diamond frame plate 23, lifting rod 21).
And the lowering of the suction part 22) is restricted.

DP is a diaphragm which is an example of a passive element, and the peripheral wall thickness portion DPa of this diaphragm DP is shown.
Is fitted into the circular groove 12b, and the holder 11 and the diaphragm cases 12 and 13 are joined 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 atmosphere by the diaphragm DP in contact with the diaphragm plate 23 and the first space S1 communicating with the flow path 15b of the pipe 15. It is divided into a second space S2. Then, the output (compressed air) of the control means 40 is supplied to the first space S1 through the pipe 15, and this output depends on the pressing force for pressing 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 regulator for low pressure setting by a single-acting variable actuator, and the regulator RL for low pressure setting is connected to the output part of the regulator RH, and outputs the output pressure of the regulator RH for high pressure,
It is possible to make the low pressure finely divided into about 256 divisions. In FIG. 4, H indicates a high pressure portion and L indicates a low pressure portion.

SV1 is a first 3-port electromagnetic switching valve for switching between high pressure and low pressure. The P port of the first switching valve SV1 is at the output of the low pressure setting regulator RL, and the R port is at high pressure. Each of them is connected to the output section of the setting regulator RH. SV2 is the second 3 for switching between negative pressure and positive pressure.
It is a port solenoid directional control valve, and P of this second directional control valve SV2.
The port is the vacuum section V, and the R port is the first switching valve SV.
A of the second switching valve SV2 connected to the A port of No. 1
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 switching valves SV1 and SV2 are demagnetized, a high pressure is applied to the first space S1 from the output section 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. The 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 recess 11 a of the holder 11,
The suction unit 22 is provided with respect to the support mechanism 10 such as the holder 11.
It is in the most lowered position.

From this state, as shown in FIG. 4B, when both the first and second switching valves SV1 and SV2 are excited, the vacuum section V causes the second switching valve SV2 to have a P port and an A port. Through the first space S1. Then, the pressure in the space S1 suddenly decreases, and the pushing-down force also rapidly decreases.
You will be able to move up and down freely.

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 causes the first switching valve SV1 to change. P port, A port and second switching valve SV
The first space S1 through the R port and the A port of
Communicate with. Then, 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 is constructed as described above, and a bonding method using this bonding head device will be described with reference to FIG. In FIG. 6, the horizontal axis represents time t. Also, 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. 6A, the speed of the movable portion 20 in FIG. 6B, and the switching in FIG. 6C and FIG. Excitation of valves SV1 and SV2
In the demagnetized state, (e) in the figure, the pressure in the first space S1 (proportional to the pushing-down force by the diaphragm DP) is shown.

Now, at times t0 to t1, the first and second
Both the switching valves SV1 and SV2 are demagnetized and the space S
With the pressure inside 1 kept at high pressure H, the moving means 30 is driven (see FIG. 1) to lower the support mechanism 10 and the movable mechanism 20 at high speed. In this state, as shown in FIG.
Since the electronic component P sucked by the suction portion 22 is considerably above the lead frame LF, there is no risk of damage even if it is lowered at a high speed, and the lower surface of the diaphragm plate 23 is pressed against the bottom surface of the recess 11a. Therefore, the movable mechanism 20 such as the suction portion 22 descends integrally with the support mechanism 10 such as the holder 11.

Next, at times t1 to t2, the first and second
Both of the switching valves SV1 and SV2 are excited so that 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 reason for communicating with the vacuum section V in this way is to rapidly reduce the pressure in the space S1 and improve the response speed.

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

Therefore, like the conventional means using only the spring K, after the electronic component P is grounded to the lead frame LF, the suction portion 22 vibrates up and down violently (jumping phenomenon) and the electronic component P is damaged. There is no such thing.

Next, at times t3 to t4, FIG.
Keep the pressure in the space S1 at a low pressure L as indicated by the solid line,
Alternatively, in this case, when 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). As a result, the electronic component P can be firmly bonded to the lead frame LF.

At times 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 the high pressure H, the moving means 30 is driven, and the supporting mechanism 10 and The movable mechanism 20 is raised.

Now, FIG. 7 is a vertical sectional view of a bonding head device according to another embodiment. In this example, the passive element DPX is the plate 23X formed of the electromagnet 29 and the magnetic material. Further, the control means is the electromagnet 29
The control means 50 controls the excitation state of the.

Then, the moving means 30 is driven so that the electronic component P sucked by the suction portion 22 is moved to the lead frame L.
When trying to ground to F, the control means 50 is driven so that the plate 23X and the electromagnet 29 have the same polarity,
Repel X and electromagnet 29. As a result, the electronic component P
Is to reduce the influence of the reaction force received from the lead frame LF so that the electronic component P is not damaged. In addition, 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 different in polarity 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, etc., but various kinds of elements such as a combination of a diaphragm and a spring for urging the diaphragm are conceivable.

[0057]

The present invention includes a support mechanism, and a movable mechanism having an upper portion supported so as to be able to move up and down with respect to the support mechanism, and a lower portion having a suction portion for sucking an electronic component, which is provided in the support mechanism. A bonding head device is configured to include a passive element and a control unit that applies an external force that pushes the movable mechanism to the support mechanism based on a set value in the passive element. Therefore, by changing the setting in the control means, it is possible to smoothly change the bonding load without replacing the parts. Also, by reducing the external force when the suction part is about to descend,
It is possible to reduce the shock applied to the electronic components and prevent the electronic components from being damaged.

[Brief description of drawings]

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

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

FIG. 3 is a vertical 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 when attempting to descend to the lowest level according to the present invention.

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

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

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

[Explanation of symbols]

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

Claims (2)

[Claims] 1. A bonding head device, comprising: a support mechanism; and a movable mechanism having an upper part that is vertically movable with respect to the support mechanism and a lower part having a suction part that sucks an electronic component. A bonding head device for an electronic component, comprising: a passive element that is provided; and control means that applies an external force that pushes down the movable mechanism to the support mechanism based on a set value in the passive element. 2. The bonding head device according to claim 1, wherein when performing the bonding, an external force for pushing down the movable mechanism to the support mechanism is weakened when the suction part is about to descend to the minimum. Method.