JP2002231789A - Pickup method of semiconductor chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a pickup operation efficiently by shortening a time required for recognizing a chip. SOLUTION: When the positions of semiconductor chips 6 on a wafer sheet 5 are detected one stage after another in a predetermined order, the positions of the next stage adjacent thereto where the semiconductor chip 6 are absent are stored in a memory 16. After detecting the positions of the semiconductor chips of one stage on the wafer sheet 5 is finished, a pickup head 8 is moved to the nearest position (a) of the next stage that is obtained from the memory 16 and to the position not existing the following semiconductor chip 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for picking up semiconductor chips cut from a wafer and attached to a wafer sheet.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a semiconductor chip is cut out from a wafer composed of a large number of individual chips. The individual chips are cut out with the wafer attached to an adhesive wafer sheet, and the cut individual chips are peeled off from the wafer sheet and picked up. Conventionally, the positioning of the individual chips for pick-up is performed by position detection by image recognition, and the position of the semiconductor chips is detected by pattern-matching a screen imaged on a wafer sheet with a pattern of a reference semiconductor chip. It is carried out.

FIG. 4 is an explanatory diagram showing a pickup operation by a conventional pickup device.

As shown in FIG. 1, a wafer holding table 51 is provided.
Is a wafer sheet 5 on which a large number of semiconductor chips 52 are attached.
3, a camera provided above the wafer holding table 51 picks up an image of the semiconductor chip 52 on the wafer sheet 53, thereby detecting the position of the semiconductor chip 52, and detecting the position of the semiconductor chip 52 at the detected position. ) Picks up the semiconductor chip 52.

At this time, if the chip recognition result is "no chip", the pickup head is pitch-fed to search for a chip. If the chip cannot be found as a result of the pitch feeding of the set number of times (in the illustrated example, six times), the row is changed to the lower row, and the pickup head is pitch-fed in the reverse direction to search for the chip. Even if “no chip” is set, the pitch is fed the set number of times because the arrangement of the semiconductor chips 52 on the wafer sheet 53 is not necessarily constant pitch due to meandering, missing teeth, and skipping due to bonding. This is because it does not become a regular array.

[0006]

In the above conventional method,
The number of pitch feeds in the case of “no chip” needs to be set to a relatively large number, assuming that there are many lower chips. If the set number of pitch feeds in the case of “no chip” increases, the number of pitch feeds of the pickup head in the reverse direction increases accordingly, so that the time spent for the pick-up operation also increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of picking up a semiconductor chip, which can shorten the chip recognition time and perform an efficient pick-up operation.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-described problems, the present invention detects a position where there is no adjacent next-stage semiconductor chip when performing position detection of semiconductor chips on a wafer sheet one by one in a predetermined order. After the position detection of one stage of the semiconductor chip on the wafer sheet is completed, the pickup unit is moved based on the latest position without the next stage semiconductor chip acquired from the storage unit. It is what was constituted.

Thus, after the position detection of one stage is completed, the position of the semiconductor chip located in the next stage is not detected in a predetermined order, and the pickup unit is moved based on the latest position where there is no semiconductor chip in the next stage. By moving at once, it is possible to shorten the chip recognition time and perform an efficient pickup operation.

[0010]

The invention according to claim 1 is a method for picking up semiconductor chips stuck on a wafer sheet in a predetermined pattern, wherein the position of the semiconductor chips on the wafer sheet is detected in a predetermined order. When performing one step at a time, a position where there is no adjacent next-stage semiconductor chip is detected and stored in the storage means, and is obtained from the storage means after the position detection of one step of the semiconductor chip on the wafer sheet is completed. A pickup unit that moves the pickup unit based on a recent position where there is no next-stage semiconductor chip. The pickup unit can be moved at a stroke based on a recent position where there is no next-stage semiconductor chip without performing position detection in a predetermined order.

According to a second aspect of the present invention, there is provided a method of picking up semiconductor chips adhered to a wafer sheet in a predetermined pattern, wherein the position of the semiconductor chips on the wafer sheet is detected one by one in a predetermined order. At this time, the presence or absence of an adjacent next-stage semiconductor chip is detected and stored together with the position in the storage means, and after the position of the first-stage semiconductor chip on the wafer sheet has been detected, the next information obtained from the storage means is obtained. A method for picking up a semiconductor chip, characterized by moving a pickup unit to a position of a recent semiconductor chip in a step, and after detecting the position of one step,
The pickup unit can be moved at a stroke to the position of the next-most recent semiconductor chip without detecting the position of the next-stage semiconductor chip in a predetermined order.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a semiconductor chip pickup device according to an embodiment of the present invention.

First, the configuration of a semiconductor chip pickup device will be described with reference to FIG. In FIG. 1, a chip supply unit 1 is configured by connecting a wafer holding table 4 on a bracket 3 erected on an XY table 2. On the wafer holding table 4, a wafer sheet 5 on which a number of semiconductor chips (hereinafter, referred to as "chips") 6 are attached is mounted. An ejector unit 7 is provided below the wafer holding table 4. The pins 7a of the ejector unit 7 are aligned with the pickup positions of the chips 6, and the chips 6 on the wafer sheet 5 are pushed up by projecting the pins 7a upward.

Above the chip supply unit 1, a pickup head 8 mounted on a moving table 9 is disposed so as to be movable horizontally. Picked up by suction. The picked-up chip 6 is moved by the moving table 9 and the holding table 1
The work 11 is mounted on the work 11 placed thereon.

Above the wafer holding table 4, an imaging unit 12 having a camera 13 is provided. Imaging unit 12
Captures an image of the chip 6 on the wafer sheet 5, and image data obtained by the imaging is transmitted to the image recognition unit 14.
The image recognition unit 14 performs image processing on the image data and detects the position of the chip 6. The CPU 15 is an overall control unit that receives the recognition result of the image recognition unit 14 and controls each unit described below.

The storage unit 16 stores various data such as programs necessary for the operation of each unit, the size of the chip 6 to be recognized, and array data on the wafer sheet 5. The pickup head driving section 17 drives the pickup head 8 and the moving table 9 for moving the pickup head 8. The ejector driving section 18 drives the ejector unit 7. The XY table driving section 19 drives the XY table 2. The display monitor 20 displays a captured image of the chip 6 and a screen for operation and input. The key input unit 35 is an input device such as a keyboard, and performs operation input and data input.

Hereinafter, the pickup operation of the semiconductor chip device of FIG. 1 will be described with reference to FIG. 2 and FIG. FIG. 2 is a flowchart showing a pickup operation of the semiconductor chip pickup device of FIG. 1 by the pickup device, and FIG. 3 is an explanatory diagram showing the pickup operation.

As shown in FIG. 3, in a state in which a wafer sheet 5 on which a large number of chips 6 are adhered is mounted on the wafer holding table 4, in step S101 shown in FIG. Then, the position of the chip 6 to be picked up is detected by the image recognition unit 14 based on the image data obtained by the imaging. If a right direction in FIG. 3 and moves the pickup head 8, the image recognition unit 14 X ₁ in the imaging range A around the X ₀
The presence or absence of the chip 6 at the position is detected.

[0020] In step S102, CPU 15 receives the recognition result of the image recognition unit 14, or without chip 6 position of the X _1, in step S103, the next stage of stage that moves the current pickup head 8 Recognize At this time, the image recognition unit 14
Detecting the presence or absence of chip 6 position (position of the lower adjacent to the position X ₁ of the chip 6 to be picked up). Where a
Since there is no chip 6 at the position, the process proceeds from step S104 to step S105. Step S105
Then, the next-stage chip-less position a is stored in the storage unit 16.

[0021] Then, in step S106, the image recognition unit 14 detects the presence or absence of chip 6 position X ₁ of the stage currently moves the pickup head 8. If there is a chip in step S106, step S11
The number of no chips is cleared with 0, and the process returns to step S101. On the other hand, if there is no chip in step S106, the number of chipless times stored in the storage unit 16 is increased by one in step S107. Then, step S1
At 08, if the number of no chips is not the maximum set value, that is, the set number of pitch feeds ("4" in the illustrated example), the process returns to step S101. When the number of chipless times reaches the maximum set value, in step S109, the storage unit 16
The pickup head 8 is moved at a stroke to the next-stage chipless position a stored in the step (a). In step S110, the number of no chips is cleared, and the process returns to step S101.

As described above, the target X of the pickup
When recognizing the chip 6 at the position _1, the position of the next stage a is also recognized, and the presence or absence of the chip 6 is confirmed. If the chip 6 is not present, the position a is stored in the storage unit 16. By doing so, when the set number of pitch feeds is reached, the pickup head 8 is moved at a stroke to the position a of the latest chip 6 of the next stage stored in the storage unit 16 at last.

As a result, the position of the chip 6 located at the next stage is not detected in a predetermined order as in the prior art.
The pickup head 8 can be quickly moved to the next chip 6, so that the chip recognition time can be reduced and an efficient pickup operation can be performed.

If there is a chip 6 in the next stage in step S104, the number of no chips is cleared in step S110, and the process returns to step S101. That is, there is no chip 6 at the target position of the pickup, and the next stage position adjacent to the chip 6 (Y ₁ , FIG. 3)
Respectively the position of Y ₂ b, the position) of the c chip 6
In the case where there is, the chip recognition can be performed without leaving the chip row of the next stage even if there is a large number of chip rows, because the number of chipless times is not increased.

Therefore, in the past, it was necessary to set a relatively large number of chips 6 on the assumption that the number of chips 6 in the next stage was large.
It is possible to reduce the chip recognition time by reducing the set number of pitch feeds.

In this embodiment, the position where there is no chip 6 next to the stage to be picked up is stored in the storage unit 16, but the presence or absence of the chip 6 next to the stage to be picked up is stored together with the position. After the detection of the position of the first stage is completed, the pickup head 8 is determined based on the presence / absence of the next stage chip 6 stored in the storage unit 16 and its position.
May be moved to the position of the latest chip 6 at the next stage.

In this embodiment, the pickup head 8 is described as being moved as the pickup section of the present invention. However, the wafer holding table 4 for holding the wafer sheet 5 of the chip 6 instead of the pickup head 8 is described. Can be moved as a pickup unit.

[0028]

According to the present invention, when a semiconductor chip stuck on a wafer sheet in a predetermined pattern is picked up by a pickup unit, after the position detection of one stage is completed, the semiconductor chip positioned at the next stage is picked up. The pickup head can be moved at a stroke without performing the position detection in a predetermined order, so that the chip recognition time can be reduced and an efficient pickup operation can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a semiconductor chip pickup device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a pickup operation of the semiconductor chip pickup device of FIG. 1;

FIG. 3 is an explanatory diagram showing a pickup operation of the semiconductor chip pickup device of FIG. 1 by a pickup device;

FIG. 4 is an explanatory view showing a pickup operation by a conventional pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip supply part 2 XY table 3 Bracket 4 Wafer holding table 5 Wafer sheet 6 Semiconductor chip 7 Ejector unit 7a Pin 8 Pickup head 8a Nozzle 9 Moving table 10 Holding table 11 Work 12 Imaging part 13 Camera 14 Image recognition part 15 CPU 16 Storage Unit 17 Pickup head drive unit 18 Ejector drive unit 19 XY table drive unit 20 Display monitor 35 Key input unit

Claims (2)

[Claims] 1. A method for picking up semiconductor chips stuck on a wafer sheet in a predetermined pattern, wherein the position of the semiconductor chips on the wafer sheet is detected step by step according to a predetermined order, and the position of the next adjacent chip is determined. The position where there is no semiconductor chip is detected and stored in the storage unit, and the latest position where there is no next-stage semiconductor chip obtained from the storage unit after the detection of the position of one stage of the semiconductor chip on the wafer sheet is completed. A pickup method for a semiconductor chip, wherein the pickup section is moved based on the following. 2. A method for picking up semiconductor chips stuck on a wafer sheet in a predetermined pattern, the method comprising detecting a position of a semiconductor chip on the wafer sheet one by one in a predetermined order, and detecting a position of a semiconductor chip on an adjacent next stage. The presence / absence of the semiconductor chip is detected and stored together with the position in the storage means, and after the position detection of one step of the semiconductor chip on the wafer sheet is completed, the latest semiconductor chip of the next step obtained from the storage means is obtained. A pickup method for a semiconductor chip, comprising: moving a pickup unit to a position.