JPH0821600B2 - Mounting method for semiconductor pellets - Google Patents

Description

TECHNICAL FIELD The present invention relates to a semiconductor pellet mounting device.

[Conventional technology]

A conventional device configuration is shown in FIG. The conventional mounting device is arranged so that the wafer ring 5 in which the semiconductor pellets 4 are arranged is moved to the X-axis.
-Displacement amount of the semiconductor pellet 4 is measured by the TV camera on the XY table 3, the TV camera 7 and the image processing unit 8 on the XY table 3, and the displacement amount data is stored in the table control unit 6.
The semiconductor pellets 4 that have driven the XY table 3 are positioned by delivering the positioned semiconductor pellets to the pick-up nozzle 21 attached to the mount arm 1 and the lead pellets 11 on the transfer rail 10. It was fixed to. Reference numeral 2 denotes an arm drive unit that drives the arm 1.

When measuring the amount of positional deviation of the semiconductor pellet 4, the image processing unit 8 inspects the defective mark 17 on the surface of the semiconductor pellet 4, and if the defective mark 17 is detected, skips the mounting operation without performing the mounting operation. Reference numeral 9 is an apparatus control unit.

[Problems to be Solved by the Invention]

In the conventional semiconductor pellet mounting device described above,
In order for the image processing unit 8 to recognize the defective pellets, the characteristics of all the semiconductor pellets 4 were measured by the characteristic measuring device before setting the semiconductor pellets in the mounting device, and the defective pellets were marked with defective marks. A scratch mark, an ink mark, or the like is used as the defective mark.

The detection accuracy of the defective mark in the image processing unit 8 largely depends on the illumination state of the defective mark, and particularly when the scratch mark is used, the detection accuracy of the defective mark is low. Normally, the cross section of the defective mark 17 is V-shaped as shown in FIG. 6, and since it diffuses light, the defective mark 17 is seen from the upper surface of the semiconductor pellet 4 as shown in FIG.
Is blackened and can be detected by the image processing unit 8. However, if the tip of the needle that marks the defect is rounded, the bottom surface of the scratch becomes flat as shown in FIG. 8 and defective as shown in FIG. It cannot be recognized because only the edge of the mark turns black.

As described above, since the detection accuracy of the defective mark 17 in the image processing unit 8 is not stable, there is a drawback that a defective pellet is mounted.

An object of the present invention is to provide a mounting device that solves the above problems.

[Differences from the Prior Art of the Invention]

The present invention is different from the above-described conventional semiconductor pellet mounting device in that the electrical characteristics of the semiconductor pellet once picked up are measured in the intermediate stage, and only the good semiconductor pellet is mounted on the lead frame.

[Means for solving the problem]

In order to achieve the above object, a semiconductor pellet mounting device according to the present invention has a pellet positioning unit, a characteristic measuring unit, and a mounting unit, and is a non-defective product that has not been inspected.
Perform a characteristic test from mixed semiconductor pellets that do not have a defective product mark, select only good semiconductor pellets, and mount this on a lead frame In the mounting device, the pellet positioning unit includes a TV camera, an image processing unit,
It consists of a table control unit and an XY table. The TV camera is for picking up images of semiconductor pellets on the XY table in which good and defective products are mixed, and the image processing unit is for picking up an image taken by the TV camera. The table control unit controls the position of the XY table based on the output of the image processing unit, and the XY table is a semiconductor based on a command from the table control unit. Positioning of the pellet is performed. The characteristic measuring unit measures the characteristic by bringing the probe needle of the probe card into contact with the semiconductor pellet transferred from the XY table to the intermediate table by the pickup nozzle of the mount unit. Then, based on the detection electric signal from the probe card, it is determined whether the semiconductor pellet to be inspected is defectively discharged or mounted. The und section transfers the semiconductor pellets on the XY table to the intermediate table, selects only good semiconductor pellets based on the output of the characteristic measuring section, and mounts them on the lead frame.

〔Example〕

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

(Embodiment 1) FIG. 1 is a block diagram showing Embodiment 1 of the present invention. The mount arm 1 can be moved in the left / right and up / down directions by an arm drive unit 2. XY table 3 and transport rail
An intermediate stage 15 and a defective discharge nozzle 16 are arranged in the middle of 10. Probe card 14 on the intermediate stage 15
Are arranged, and the probe card drive unit 13 allows the probe card 14 to move up and down. The TV camera 7 is arranged on the XY table 3 and is connected to the image processing unit 8.

Semiconductor pellets 4 arranged on the wafer ring 5
Is taken by the TV camera 7, and the image processor 8 measures the amount of positional deviation of the semiconductor pellet 4. The measured positional deviation amount is transferred from the image processing unit 8 to the table control unit 6,
The table control unit 6 drives the XY table 3 according to the amount of positional deviation passed and positions the semiconductor pellet 4. The positioned semiconductor pellet 4 is picked up by the pickup nozzle 21 attached to the mount arm 1 and placed on the intermediate stage 15. After that, the mount arm 1 is once moved to the transport rail 10 side, and then the probe card 14 descends to the intermediate stage 15 to measure the electrical characteristics of the semiconductor pellet 4 by the characteristic measuring unit 12.

2 and 3 show the details of the intermediate stage. Correction claws 18 are arranged on the four sides of the intermediate stage 15, and after the semiconductor pellets 4 are placed in the center of the intermediate stage 15, the correction claws 18 move to the center and press in the four sides of the semiconductor pellets 4. The posture is corrected, and at the same time, the semiconductor pellet 4 is fixed by the vacuum force from the pellet suction hole. After that, the probe card 14 descends from above, the measuring needle 20 contacts the semiconductor pellet 4, and then the electrical characteristics are measured. The measurement result is transferred from the characteristic measuring unit 12 to the device control unit 9, and it is determined whether the defect is discharged or the lead frame is mounted.

After the electrical measurement is completed, the probe card 14 is raised, the correction claw 18 is retracted, the vacuum of the intermediate stage 15 is broken, and the pickup nozzle 21 picks it up again. The semiconductor pellets 4 thus picked up are dropped into the defective discharge nozzle 16 in the case of a defective product or mounted on the lead frame 11 in the case of a defective product according to a command from the device control unit 9.

Second Embodiment FIG. 4 is a configuration diagram of a second embodiment of the present invention. 22 is the second
It is attached to the mount arm 1 with the pickup nozzle of. The distance between the pickup nozzle 21 and the pickup nozzle 22 is equal to the distance from the pickup position of the semiconductor pellet 4 to the center of the intermediate stage 15, and the intermediate stage 15
Is intermediate between the pickup position of the semiconductor pellet 4 and the mount position on the lead frame 11. The arm drive unit 2 is movable not only in the vertical and horizontal directions but also in the front-back direction. In this embodiment, two pickup nozzles are arranged.
The reference numeral 21 serves to transfer the semiconductor pellet 4 from the XY table to the intermediate stage 15, and the pickup nozzle 22 serves to transfer the semiconductor pellet 4 from the intermediate stage 15 to the lead frame 11. While measuring the characteristics of the semiconductor pellet 4 in the intermediate stage 15, the mount arm 1 is retracted in the front-rear direction.

Since there are two pickup nozzles as described above, there is an advantage that the processing speed per semiconductor pellet is increased.

〔The invention's effect〕

As described above, according to the present invention, it is possible to mount only good semiconductor pellets by measuring electrical characteristics of semiconductor pellets once picked up in an intermediate stage, and to prevent defective semiconductor pellets from being mounted. it can. In addition, since the characteristics of all semiconductor pellets are checked in the equipment, the process of checking the characteristics and making a defect mark with another equipment can be omitted, and the probe can be used without marking the pellets as good or defective. Only non-defective pellets can be sorted based on the electrical signal detected by the card, and sorting errors due to mark reading can be prevented. Furthermore, the sorted non-defective pellets are mounted directly on the lead frame, so non-defective non-test・ A series of operations such as acceptance of pellets containing defective products, characteristic test, sorting and mounting can be efficiently processed in one process, and these operations are processed by one device. Compared with the case where the operations of (1) and (2) are processed by separate devices, there are no cases where human or mechanical errors occur.

[Brief description of drawings]

FIG. 1 is a configuration diagram of Embodiment 1 of the present invention, FIG. 2 is a detailed diagram of an intermediate stage in the present invention, and FIG. 3 is a diagram showing a state of an intermediate stage portion during characteristic measurement in the present invention, FIG. FIG. 5 is a configuration diagram of a second embodiment of the present invention, FIG. 5 is a configuration diagram of a conventional semiconductor pellet mounting device, and FIGS. 6 to 9 are views for explaining a defective mark detection state. 1 ... Mount arm, 2 ... Arm drive unit 3 ... XY table, 4 ... Semiconductor pellet 5 ... Wafer ring, 6 ... Table control unit 7 ... TV camera, 8 ... Image processing unit 9 ...... Device control unit, 10 Transport rail, 11 Lead frame, 12 Characteristics measurement unit, 13 Probe card drive unit, 14 Probe card, 15 Intermediate stage, 16 Defective ejection nozzle, 17 … Defective mark, 18 …… Correcting claw 19 …… Pellet suction hole, 20 …… Inspection needle 21,22 …… Pickup nozzle

Claims (1)

[Claims] 1. A step of arranging and positioning a wafer ring on which a plurality of semiconductor pellets, which have not been subjected to electrical characteristic inspection, are arranged on a table, and a step of picking up one semiconductor pellet on the table. The step of measuring the electrical characteristics of the one semiconductor pellet picked up, and if the electrical characteristics of the one semiconductor pellet are good according to the measurement result of the electrical characteristics, the one semiconductor pellet is mounted on a lead frame. If the product is defective, the semiconductor pellet mounting method including the step of discharging the one semiconductor pellet.