JPH05259233A - Wafer marking device - Google Patents

Abstract

PURPOSE:To adjust size automatically so that the size of a defective mark put on a semiconductor wafer is kept constant at all times even when the viscosity of ink for displaying the defective mark changes. CONSTITUTION:An ink applicator member 4 made of wire moves in the axial direction while penetrating an ink vessel 2 pushes out ink from the front end of the cylindrical body 3 of the ink vessel 2. A solenoid 6 is mounted on the reverse side to the cylindrical body 3 of the ink vessel 2, and the member 4 is coupled with the core 7 of the solenoid 6. A first stroke adjusting nut 9 is screwed to a shaft screw 8 unified with a core 7. The first stroke adjusting nut 9 is engaged with a second stroke adjusting nut 21 operated by the spline gear 15a of a stepping motor 15. The stepping motor 15 is operated by the command of a computer is response to information from a TV camera that monitors ink applied to a semiconductor wafer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer marking apparatus for giving a defective mark to a defective chip among a large number of semiconductor chips formed on a semiconductor wafer.

[0002]

2. Description of the Related Art A conventional wafer marking device will be described with reference to FIG. A small-diameter cylindrical body 3 is formed at the tip of an ink container 2 containing ink 1 for displaying a defective mark, and the inside of the cylindrical body 3 is used as an ink pouring member and is about 0.1 to 1 mm.
The φ nylon wire 4 penetrates through a slight gap.
The nylon wire 4 passes through the ink container 2 and is connected to a core 7 of a solenoid (moving member) 6 provided integrally with the ink container 2 via a fixing member 5 on the side opposite to the ink cylinder 2. The shaft screw 8 provided integrally with the core 7 is the solenoid 6
The first stroke adjusting nut 9 is screwed onto the shaft screw 8.

An arm portion 10 is provided on the frame 6a of the solenoid 6, and a screw portion 10a formed at the tip thereof.
The second stroke adjusting nut 11 is screwed into the. Further, the solenoid 6 is connected to a controller (not shown) via a lead wire 12.

In the above conventional apparatus, the nylon wire 4 moves integrally with the core 7 in the predetermined stroke axis direction by exciting the solenoid 6 with the output of the controller. There is a small gap between the nylon wire 4 and the cylinder 3,
Further, since the ink 1 has a viscosity, the ink 1 in the reservoir of the ink container 2 is drawn into the minute gap as the nylon wire 4 slides in the cylinder 3. Then, the ink 1 adheres to the surface of the nylon wire 4, flows out to the tip of the cylindrical body 3 together with the nylon wire 4, and is ejected to the tip of the nylon wire 4 in the form of water droplets. Therefore, the larger the stroke of the nylon wire 4 is, the more ink 1 is applied as the defective mark 14 on the semiconductor wafer 13. The stroke of nylon wire 4 is 1st and 2nd
It is determined by the distance L between the stroke adjusting nuts 9 and 11.

By the way, the viscosity of the ink 1 decreases with time after mixing as shown in FIG. If the stroke of the nylon wire 4 is the same, as the ink viscosity decreases, the nylon wire 4
The amount of ink ejected from the tip of the ink is reduced, and the defective mark 14 is gradually reduced.

The defect mark 14 is used for recognizing a defective product when a semiconductor wafer is diced into chips and then picked up to assemble a semiconductor device. Normally, this recognition is performed by an industrial TV. Pattern recognition is performed. Specifically, the defective mark 14 is pattern-recognized by an industrial TV, and the defective mark 14 is not picked up.
Causes the next chip to skip. This defective mark 1
In the pattern recognition of No. 4, there is a minimum size that can be recognized depending on the resolution of the industrial TV and the algorithm of the pattern recognition software.

[0007]

From the above, although the size of the defective mark is always required to be a certain size or more, the conventional apparatus reduces the ink viscosity with the passage of time. Along with this, there is a problem that the amount of ink poured out decreases due to the movement of the nylon wire along the same stroke axis, and the size of the defective mark gradually decreases.

Further, a human visually monitors that the defective mark does not become smaller than the recognizable minimum size, and when the mark size becomes small, the temporary device is stopped, and the first and second stroke adjusting nuts 9 shown in FIG. 11, the stroke of the ink pouring member 4 may be adjusted. However, this requires both the work of monitoring and correcting the mark size.

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

[0010]

A wafer marking device according to the present invention comprises an ink pouring member made of a wire rod that moves axially through an ink container and pours ink from a pouring port of the ink container onto a semiconductor wafer. Based on the information from the moving means for moving the ink pouring member along the axis, the stroke adjusting means for adjusting the stroke of the ink pouring member, the TV camera for monitoring the ink on the semiconductor wafer, and the TV camera. It is characterized by including a control means for sending a command to the stroke adjusting means and controlling the command.

The moving means comprises a solenoid and a core connected to the ink pouring member, and the stroke adjusting means includes a stepping motor and a mechanism for converting rotational movement into linear movement in the stepping motor. And a locking member that regulates the movement of the core.

Further, according to the present invention, the axial movement of the ink pouring member and the stroke adjustment may be performed by a stroke operation / stroke adjusting means which operates according to a command from the control means. It is preferable that the stroke adjusting means / stroke adjusting means is composed of a stepping motor, and the ink pouring member and the stepping motor are linked via a rotation / linear motion converting mechanism.

[0013]

When the ink viscosity decreases with the lapse of time and the ink pouring amount from the ink pouring member decreases, the TV camera monitors this and sends the information to the control means. The stroke adjusting means operates according to a command from the control means to increase the stroke amount of the ink pouring member. As a result, a fixed amount of ink is always poured as a defective product mark on the defective chip of the semiconductor wafer.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same elements as those of the related art will be described with the same reference numerals.

FIG. 1 is a schematic view of the present invention, and FIG. 2 is a detailed view of the mark applying device A of FIG. Explaining with reference to FIG. 2, a nylon wire 4 as an ink pouring member penetrates through a cylindrical body 3 formed at the tip of an ink container 2 containing the ink 1. A solenoid 6 is provided on the opposite side of the cylinder 3 of the ink container 2 via a fixing member 5, and the nylon wire 4 extends through the ink container 2 toward the solenoid 6 and has a core 7 at its core 7. Are united together.

A shaft screw 8 is provided integrally with the core 7, and the shaft screw 8 is provided with a first stroke adjusting nut 9. The solenoid 6 has the frame 6a.
It is used in combination with a spring (not shown) provided inside, and this spring is urged to return the core 7 moved forward by the excitation of the solenoid 6 to the original position.

The second stroke adjusting nut 21 for restricting the stroke of the first stroke adjusting nut 8 is screwed onto the screw shaft 20 fixed at a predetermined position by any means. The second stroke adjusting nut 21 is provided with a spline gear 1 of a stepping motor 15 which is a driving means thereof.
5a is engaged. The stepping motor 15 and the solenoid 6 are the central processing unit (hereinafter CP) of the control means that constitutes the feedback control device 17 shown in FIG.
It operates by the signal from 16).

The feedback control device 17 is
The CPU 16, the stepping motor 15, and the TV camera 18 provided above the mark giving device A and constantly monitoring the mark giving position A are connected to each other.
Therefore, the image information monitored by the TV camera 18 is C
The instruction from the CPU 16 is sent to the PU 16 and is transmitted to the stepping motor 15, whereby the spline gear 1
The stroke of the nylon wire 4 is adjusted by rotating 5a by a predetermined amount in the forward and reverse directions.

That is, when the solenoid 6 is ON, the first stroke adjusting nut 9 is in contact with the solenoid 6 side. At this time, the nylon wire 4 sends out the ink 1 in the ink container 2 and the defective mark. 14 is a state applied to the semiconductor wafer 13. Also solenoid 6
When is OFF, the first and second stroke adjusting nuts 9 and 21 are in contact with each other by the action of a spring (not shown), that is, in a standby state. Generally, the larger the distance L between the first and second stroke adjusting nuts 9 and 21 is, the more the amount of the ink 1 that is sent out increases,
The defective mark 14 becomes larger, and conversely, the smaller the stroke, the smaller the defective mark 14. Further, the defective mark 14 becomes smaller even if the viscosity of the ink 1 increases.

In this embodiment, when the viscosity of the ink 1 increases and the defective mark 14 becomes smaller, the information is taken in by the TV camera 18 and sent to the CPU 16. C
PU16 is a stepping motor 15 for stroke adjustment
Is rotated in the direction of increasing stroke to prepare for the next defective mark operation. The next defective product mark 14 has a stroke larger than that of the previous ink operation of the ink pouring member 4, so that the mark size becomes large. By repeating this operation, the stroke of the nylon wire 4 can be increased as the ink viscosity increases, and the defective product mark 14 having a constant size can always be provided on the semiconductor wafer 13.

In the first embodiment, the TV camera 18 may be equipped with a magnifying lens, if necessary, and an illuminating device for illuminating the defective mark 14 may be added. The stepping motor 15 and the second stroke adjusting nut 21 may be connected in any arbitrary configuration as long as the rotational movement thereof can be converted into a linear movement. For example, a worm is formed on the shaft of the stepping motor 15 while A worm may be formed on the second stroke adjusting nut 21, and the second stroke adjusting nut 21 may be slidably fitted on the spline shaft.

Next, a second embodiment will be described with reference to FIGS. In the second embodiment, the stroke operation and stroke adjustment of the nylon wire 4 are directly performed by the stepping motor 25. Therefore, the worm gear 24 is attached to the motor shaft 25a of the stepping motor 25, while the spiral shaft that non-rotatably penetrates the fixing member 5 of the ink container 2 with the key 22 at the end of the nylon wire 4. The gear 23 is provided, and the shaft gear 23
And the worm gear 24 described above mesh with each other. The other structure is the same as that of the first embodiment.

According to the second embodiment, the nylon wire 4 is stroked by the stepping motor 25 via the worm gear 24 and the shaft gear 23, and the number of operating pulses of the stepping motor 25 is increased or decreased by a command from the CPU 16 to reduce the nylon. The stroke of line 4 can also be adjusted.
In the second embodiment as well, the stepping motor 25
The linking structure between the nylon wire 4 and the nylon wire 4 is not limited to the illustrated example, and a pinion and a rack may be used as long as they can transmit the rotational motion of the stepping motor 25 to the nylon wire 4 as a linear motion.

[0024]

As described above, according to the wafer marking apparatus of the present invention, the viscosity of the defective mark ink applied to the semiconductor wafer changes, and the size is automatically adjusted even if the mark size decreases. Therefore, it is not necessary to monitor and adjust humans, which was necessary in the past. Further, since the mark is recognized at the same time as the marking, it is possible to prevent marking mistakes and the like, and there is an effect that the conventionally required check after marking is unnecessary.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a wafer marking apparatus according to a first embodiment of the present invention.

FIG. 2 is a detailed view of a portion A of FIG.

FIG. 3 is an explanatory diagram of a wafer marking device according to a second embodiment of the present invention.

4 is a cross-sectional view of the screw shaft of FIG.

FIG. 5 is a side view showing a conventional wafer marking device by cutting a part thereof.

FIG. 6 is a graph showing the relationship between viscosity and time elapsed after ink preparation.

[Explanation of symbols]

1 ... Ink, 2 ... Ink container, 3 ... Cylindrical body, 4 ... Nylon wire, 6 ... Solenoid, 7 ... Core, 8 ... Shaft screw, 9 ... First
Stroke adjusting nut, 13 ... Semiconductor wafer, 14 ... Defective mark, 16 ... CPU, 17 ... Feedback control device, 18 ... TV camera, 21 ... Second stroke adjusting nut, 25 ... Stepping motor.

Claims (4)

[Claims] 1. An ink container that moves axially through an ink container,
An ink pouring member composed of a wire rod for pouring ink from the pouring port of the ink container to the semiconductor wafer, a moving means for axially moving the ink pouring member, and a stroke adjusting means for adjusting the stroke of the ink pouring member. A wafer marking device including a TV camera for monitoring ink on the semiconductor wafer and a control means for sending a command to the stroke adjusting means on the basis of information from the TV camera to control the stroke adjusting means. 2. The moving means comprises a solenoid and a core connected to the ink pouring member, and the stroke adjusting means includes a stepping motor and a mechanism for converting rotational movement into linear movement by the stepping motor. 2. A coupling member that is connected via a locking member that restricts movement of the core.
Wafer marking device described. 3. Moving axially through the ink container,
An ink pouring member made of a wire material for pouring ink from the pouring port of the ink container to the semiconductor wafer, a stroke operation and stroke adjusting means for moving the ink pouring member by a predetermined stroke axis line, and monitoring the ink of the semiconductor wafer A wafer marking apparatus including a TV camera and a control means for sending a command to the stroke adjusting / stroke adjusting means based on information from the TV camera and controlling the command. 4. The stroke adjusting device for combined stroke operation is a stepping motor, and the ink pouring member is linked with the stepping motor through a rotation / linear motion converting mechanism. Wafer marking device.