JPH06177184A - Paste application device in bonding device for semiconductor pellet - Google Patents

Abstract

PURPOSE:To realize easy and accurate setting of the height of a nozzle. CONSTITUTION:A ball screw 27 is screwed into a ball screw 24a supported to a guide 24 arranged in the direction of the arrow A and supported vertically to a moving element 26 which is movable in the direction of the arrow A being driven by a motor 25. Further, a syringe 31 is installed through a fixture 30 in the moving element 29 which is screwed into the ball screw 27 and movable vertically being driven by a pulse motor 28 to make the syringe 31 movable in the direction of the arrow A and also vertically, and on the moving locus of the syringe 31 is arranged a reference table 34 provided with a detector 39 for detecting a relative movement between a shaft 36 for supporting a table 35 and a case 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste applying apparatus in a semiconductor pellet bonding apparatus for applying paste on an island of a lead frame.

[0002]

2. Description of the Related Art In a semiconductor pellet bonding apparatus, a semiconductor pellet (hereinafter simply referred to as "pellet") is bonded onto an island of a lead frame supplied from a supply section, and a lead frame having the pellet mounted therein is stored in a storage section. The operation is carried out to.

By the way, when the pellets are bonded onto the islands of the lead frame, it is necessary to perform an operation of applying an adhesive, that is, a paste for bonding the pellets onto the islands.

The paste applying operation will be described below with reference to FIGS.
Will be explained.

FIG. 3 is a side view showing the configuration of a conventional paste coating apparatus. FIG. 4 is a diagram showing the operation of the conventional paste coating apparatus.

First, when the lead frame 1 is transported on the transport rail 2 and positioned on the support table 2a provided at the paste coating position, the paste coating device 3 drives the pulse motor 4 and the pulse motor 4 is driven. The mover 6 descends due to the rotation of the connected ball screw 5. Along with the lowering of the mover 6, the syringe 8 detachably supported by the mover 6 via the attachment 7 descends. Then, the tip of the nozzle 8a provided at the lower end of the syringe 8 is lowered to the coating height a of the paste 9 and then the pulse motor 4 is stopped, whereby the syringe 8 is stopped.

When the syringe 8 is positioned at the coating height a, the coating controller 10 operates to coat a predetermined amount of paste 9 from the inside of the syringe 8 onto the island (not shown) of the lead frame 1. When the application of the paste 9 is completed, the pulse motor 4 is driven in the reverse direction, the syringe 8 is raised to the standby position, and the application operation is completed. The standby position is the movement origin o of the syringe 8. Further, the coating height a is a position where an appropriate gap t1 is formed between the surface of the lead frame 1 and the tip of the nozzle 8a of the syringe 8, and it is necessary to accurately set the coating height a in order to coat the paste 9 well.

[0008]

However, in the coating device 3 described above, the coating height is changed due to a change in the tip position of the nozzle 8a due to the replacement of the syringe 8 or a change in the lead frame plate thickness due to a change in the type of the lead frame 1. Since the gap t1 at the height a changes, it is necessary to reset the coating height a each time the syringe 8 is replaced or the product type is changed. And this coating height a
In the setting operation, first, the pulse motor 4 is driven by the operator's manual operation to gradually lower the syringe 8 from the standby position (origin o) and confirm the tip position of the nozzle 8a of the syringe 8 while checking the lead frame. Nozzle 8a on surface b
The tip is brought into contact, and the moving distance ◆ 1 of the nozzle 8a from the origin o to the lead frame surface b is obtained from the driving amount of the pulse motor 4 at this time, and from this moving distance ◆ 1 and the gap t1, from the origin o. This is done by calculating the moving distance ♦ 2 of the nozzle 8a to the coating height a. However, during this work, the operator is forced to perform the difficult work of lowering the syringe 8 to a position where the nozzle 8a abuts on the lead frame 1 while visually confirming the tip end position of the nozzle 8a, which causes great fatigue. In addition, there is a problem that the nozzle 8a is damaged due to an operation error. Further, there is a problem that a stable bonding operation cannot be performed due to a difference in working time depending on the skill level of the operator.

The present invention, without being affected by human
An object of the present invention is to provide a paste coating apparatus in a semiconductor pellet bonding apparatus that can easily and accurately set the nozzle height during paste coating.

[0010]

SUMMARY OF THE INVENTION The present invention is a paste coating apparatus in a semiconductor pellet bonding apparatus for coating a paste at a predetermined position on a lead frame, the syringe having a coating nozzle, and a syringe capable of filling the paste, A first moving means for supporting the syringe so as to be movable back and forth in the application direction of the paste; a second moving means for supporting the first moving means so as to be movable in a direction orthogonal to the moving direction; It is characterized by comprising a reference table arranged on the movement trajectory and a detection means for detecting the contact of the nozzle with the reference table.

[0011]

According to the present invention, the syringe having the coating nozzle and capable of filling the paste is movably supported in the coating direction of the paste by the first moving means, and the first moving means is the second moving means. Is movably supported in a direction orthogonal to the moving direction of the first moving means, and a reference table is arranged on the moving path of the syringe in the first and second moving means, and the detecting means is used. Since the contact of the nozzle with the reference table is detected, it is possible to easily know the tip position of the nozzle, and based on the position of the reference table, the nozzle of the nozzle with respect to the lead frame at the time of applying the paste is detected. The height can be set accurately.

[0012]

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

FIG. 1 is a side view showing the structure of a paste coating apparatus in a semiconductor pellet bonding apparatus of the present invention. FIG. 2 is a diagram showing the operation of the paste coating apparatus in the semiconductor pellet bonding apparatus of the present invention.

In the figure, the paste coating device 20 includes a guide rod 24 arranged in a direction (arrow A direction) orthogonal to the carrying direction of the lead frame 23 on the carrying rail 22 installed on the base 21, and a guide bar 24. Of the pulse motor 25 supported in parallel with the longitudinal direction of the pulse motor 25.
5 is screwed into the rotatable ball screw 24a by the drive of 5,
By the rotation of the ball screw 24a, a mover 26 that is movable in the direction of arrow A, a ball screw 27 that is vertically supported by the mover 26, and a ball screw 27 that is screwed into the ball screw 27 and is driven by a pulse motor 28. By a rotation of 27, a movable element 29 that is movable in the vertical direction, a syringe 31 that is detachably attached to an attachment 30 provided on the movable element 29, is connected to the syringe 31, and is filled in the syringe 31. Coating controller 3 for controlling the coating of the paste 32
3 and 3.

The syringe 3 on the side of the carrier rail 23
A reference table 34 mounted on a column (not shown) protruding from the base 21 is located on the movement path of 1. The reference table 34 includes a table 35 having a smooth table surface c, and a case 37 in which a shaft 36 supporting the table 35 is attached movably in the axial direction of the shaft 36.
And between the table 35 and the case 37 to urge the table upward, and an abutting portion (not shown) provided on the shaft 36 abuts a stopper (not shown) provided in the case 37. And a spring 38 that elastically supports the table 35. Further, a detector 39 for detecting relative movement of the shaft 36 with respect to the case 37 is provided in the case 37, and the detector 39 is connected to the control device 40. The control device 40 has a setting unit 41 and is connected to the pulse motors 25, 27 and the coating control unit 33, and comprehensively controls the coating device 20. The table surface c of the reference table 34 is set at a position having a predetermined relative distance ◆ 3 with the support surface d of the support table 22a of the lead frame 23 provided corresponding to the application position of the paste 32 on the transport rail 22. The relative distance ◆ 3 is stored in the setting unit 41 in advance.

Further, the suction nozzle 42 of the lead frame 23 is attached to the mover 29 together with the syringe 31, and the carrier rail 22 and the stocker 43 which is provided adjacent to the carrier rail 22 and accommodates the lead frames 23 in a stacked state,
And a reject space 44 that accommodates the defective lead frame 23.

Next, the operation will be described.

First, when performing the coating operation, an operation panel (not shown) is operated to switch to the coating height a setting mode. Based on this switching signal, the control device 40 drives the pulse motor 25 to move the syringe 31 onto the reference table 34. Next, the pulse motor 28 is driven to lower the syringe 31 onto the reference table 34. Then, the pulse motor 28 is stopped based on the detection signal of the detector 39 output by detecting the relative movement between the shaft 36 and the case 37 caused by the contact of the tip of the nozzle 31a with the table surface c. At this time, the control device 40 detects the drive amount from when the pulse motor 28 starts driving to when it stops, and the moving distance ◆ 4 of the nozzle 31a from the origin o to the table surface c is detected from this detected value. Calculated by calculation. Then, the calculation result and the setting unit 41 are set in advance.
Based on the relative distance ♦ 3 between the table surface c of the reference table 34 and the support surface d of the support table 22a set to, the gap t1, and the thickness t2 of the lead frame 1 to be supplied, from the origin o. Moving distance to coating height a 5
To calculate. Then, the following coating operation is performed on the basis of the moving distance 5.

First, the pulse motor 25 is driven and the mover 26 is moved to position the suction nozzle 42 on the stocker 43. Next, by driving the pulse motor 28 and lowering the mover 29, the suction nozzle 42
Is lowered and brought into contact with the lead frame 23 stacked in the stocker 43. This contact is detected by a detector (not shown), and the pulse motor 28 is stopped based on this detection signal. After that, a vacuum is generated in the suction nozzle 42 and the suction nozzle 42 is raised to suck the lead frame 23. After that, the thickness of the lead frame 23 sucked by the suction nozzle 42 is detected by a thickness detecting means (not shown), and the lead frame 2 is detected based on the detected value.
It is decided to take two sheets of No. 3. When it is determined that the two nozzles are taken, the suction nozzle 42 is moved onto the reject space 44, and the vacuum of the suction nozzle 42 is released.
The two lead frames 23 taken into the reject space 44 are discharged. Further, when it is determined that the number of the lead frames 23 is one, the suction nozzle 42 is set to the transport rail 22.
And move the lead frame 23 onto the transport rail 22.
To place.

The lead frame 23 placed on the transport rail 22 is transported on the transport rail 22, and an unillustrated island at the head position is positioned on the support table 22a, which is the application position of the paste 32. Next, mover 26
The movement of the syringe moves the syringe 31 onto the support table 22a. Then, the syringe 31 is lowered to the coating height a by driving the pulse motor 28. Next, according to a command from the dispense controller 33, a predetermined amount of paste 32 is applied onto the island. After the application of the paste 32 is completed, the syringe 31 moves up to the standby position. After that, the lead frame 23 is transported on the transport rail 22 at each island pitch, and the paste 32 is sequentially applied onto the islands. Then, the lead frame 23 on which the paste 32 has been applied is carried on the carrying rail 22 and sent to a bonding process (not shown).

While the coating operation is repeated, when the paste 32 in the syringe 31 is used up and replaced with a new cylinder 31, the gap t1 at the coating height a is changed, the operation described above is performed. The coating height a can be automatically corrected.

According to the present invention, the reference table 34 having the table surface c is provided at a predetermined relative distance to the support table 22a, and the nozzle 3 for the reference table 34 is provided.
The tip position of the nozzle 31a is detected by detecting the contact of the tip of 1a, and the moving distance ◆ 4 from the origin o of the nozzle 31a to the coating height a at that time is calculated, and coating is performed based on this moving distance ◆ 4. Since the moving distance ♦ 5 to the height a is calculated, the coating height a can be set easily and accurately without any intervention of human operation.

The table 35 is elastically supported by a spring 38, and stops the pulse motor 28 when the nozzle 31a comes into contact with the table surface c and stops the descending of the syringe 31. When the nozzle 31a contacts the surface c, the nozzle 21a is not damaged.

In the above embodiment, the moving element 29 is provided with the syringe 31 and the suction nozzle 42, but a moving mechanism may be provided for each of the syringe 31 and the suction nozzle 42.

In the above embodiment, the reference table 34 having the table surface c is provided at a predetermined relative distance to the support table 22a, and the tip of the nozzle 31a is brought into contact with the reference table 34 in the reference table 34. Nozzle 31a by detecting with the detector 39
Although the configuration has been described in which the tip position is detected, the reference table 34 does not necessarily have to be provided alone, and may be provided in combination with other components. For example, the table surface c of the reference table 34 is replaced with the support surface d of the support table 22a.
Alternatively, a detecting means for detecting the contact of the nozzle 31a with the support table 22a may be provided on the mounting tool 30 side.

[0026]

According to the present invention, it is possible to easily and accurately set the nozzle height during paste application.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a paste coating apparatus in a semiconductor pellet bonding apparatus of the present invention.

FIG. 2 is a diagram showing an operation of a paste coating apparatus in the semiconductor pellet bonding apparatus of the present invention.

FIG. 3 is a side view showing a configuration of a conventional paste coating device.

FIG. 4 is a diagram showing an operation of a conventional paste coating device.

[Explanation of symbols]

 20 paste application device 22 transport rail 23 lead frame 24, 27 ball screw 26, 29 mover 31 syringe 31a nozzle 32 paste 33 application control unit 34 reference table 35 table 36 shaft 37 case 39 detector 40 control device 41 setting unit

Claims (1)

[Claims] 1. A paste applicator in a semiconductor pellet bonding apparatus for applying a paste at a predetermined position on a lead frame, the syringe having an applicator nozzle and capable of filling the paste, and the syringe in a paste application direction. First moving means for movably supporting it, second moving means for movably supporting the first moving means in a direction orthogonal to its moving direction, and a reference arranged on the moving path of the syringe. A paste applying apparatus in a semiconductor pellet bonding apparatus, comprising: a table; and a detection means for detecting contact of the nozzle with the reference table.