JP2794666B2 - Lighting method of semiconductor chip - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for illuminating a semiconductor chip, and more particularly to a method for performing illumination for pattern recognition from below.

[Summary of the Invention]

The present invention is a method of illuminating a semiconductor chip in which a wafer fixing block provided at a lower portion of a wafer table of a semiconductor chip pickup device is made of a transparent material, and illumination for pattern recognition is performed from below.

[Conventional technology]

2. Description of the Related Art In recent years, semiconductor integrated circuits (hereinafter, abbreviated as ICs) have been highly integrated and highly functional, and production has been rationalized.

Under such an environment, the IC manufacturing process is also required to have high precision, labor saving and rationalization, and even in a die bonder having a part of the structure shown in FIG. Pattern recognition is employed as a position detecting means in the pickup step. (Electronic Materials, 1987, separate volume, pp. 121-122) An invention has also been proposed in which the position of an IC chip is detected by pattern recognition. (For example,
[Problem to be Solved by the Invention] In a pattern recognition device, illumination is required to capture an image of an IC chip with a video camera.
Illumination methods from the video camera side above the IC chip are widely used (see, for example, JP-A-63-208238).
An illumination method from the wafer fixed block side below the chip is also used. However, with the lighting method from the video camera side above the IC chip, the lighting may be unstable due to the surface condition of the IC chip. The response became complicated. The illumination method from the wafer fixing block side under the IC chip is not affected by the surface condition of the IC chip. It was necessary to reduce the productivity.

[Means to solve the problem]

Therefore, in order to solve the above-mentioned problems, the present invention provides a transparent or translucent sheet in which a wafer which can be divided into semiconductor chips is adhered to the upper surface, a wafer fixing block which sucks and fixes the sheet from the lower surface, A light source for illuminating the separated semiconductor chip, a video camera provided on the wafer fixing block, a push-up mechanism provided on the wafer fixing block, and a collet for vacuum-sucking the divided semiconductor chips. By performing pattern recognition by photographing the divided semiconductor chip, the position of the divided semiconductor chip is detected, the divided semiconductor chip is lifted by the push-up mechanism, and the semiconductor chip is picked up from the sheet by the collet. In the method, if the previous wafer fixing block is made of transparent material Moni, provided the light source on the outer peripheral portion of the wafer fixed block,
The divided semiconductor chips are illuminated by the light source through the fixed wafer fixing block and the sheet, and a shadow image of one divided semiconductor chip on the optical axis of the video camera is taken, thereby dividing the divided semiconductor chips. Performs pattern recognition including X-axis coordinate, Y-axis coordinate, angle θ, and shape defect of a semiconductor chip, and positions the collet and the divided semiconductor chip, thereby fixing the wafer even when illumination for pattern recognition is performed from below. We propose a lighting method for semiconductor chips that does not leave shadows from blocks on IC chips.

[Action]

The present invention provides a transparent or translucent sheet having an upper surface to which a wafer capable of being divided into IC chips is adhered, and a wafer fixing block for adsorbing and fixing the lower surface of the sheet with a transparent material. A semiconductor light source is provided on the outer periphery of the wafer fixing block, and the divided semiconductor chips are illuminated by the light source through the fixed wafer fixing block and the sheet while the wafer fixing block is literally fixed. 1 on axis
By taking a shadow image of the divided semiconductor chips, pattern recognition including the X-axis coordinate, the Y-axis coordinate, the angle θ, and the shape defect of the divided semiconductor chips is performed,
By positioning the collet and the divided semiconductor chip, illumination for pattern recognition can be performed from below without moving the wafer fixing block up and down.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 and FIG.

FIG. 1 is a side view showing a method of illuminating a semiconductor chip according to one embodiment of the present invention, and FIGS. 2A and 2B are diagrams showing the operation of a pickup device for picking up an IC chip illuminated by the method of illuminating a semiconductor chip of FIG. FIG.

In FIG. 1, 1 is a video camera for pattern recognition,
Numeral 2 denotes a wafer fixing block made of a transparent material having mechanical strength such as quartz glass or reinforced plastic, for example, a suction hole 3 for sheet suction provided on the upper surface, and a vacuum provided inside for generating suction force. The wafer fixing block 2 is configured together with the suction hollow section 4. The wafer fixing block 2 is provided with a push-up mechanism 5 in a hollow portion 4 therein, and a light source 6 for illumination is provided on an outer peripheral portion.
The light source 6 is desirably arranged so as to be coaxial with the video camera 1, and ring illumination is ideal. However, the ring illumination is not necessarily required as long as it has the same effect. Above the wafer fixing block 2, a transparent or translucent sheet 8 having an adhesive surface on the upper surface, affixing the wafer on the upper surface, and dicing the wafer into single IC chips 7 by dicing is provided with a wafer carrier ( (Not shown) and attached to a wafer table (not shown).

The method of illuminating a semiconductor chip and the method of recognizing a pattern of the present invention will be described below. As shown in FIG. 1, a sheet 8 attached to a wafer table (not shown) is slightly lifted above a horizontal plane by a wafer fixing block 2, the sheet 8 is stretched, and the interval between the IC chips 7 is slightly smaller than the dicing state. Spread and held. Then, the transparent wafer fixing block 5 is illuminated by the light source 6 while being fixed, and the IC chip 7 on the upper surface of the sheet 8 is imaged by the video camera 1 provided on the upper side, and a known method for binarizing the imaged image. Is used for pattern recognition. By pattern recognition, the IC chip 7 is located at the X coordinate value,
At the same time when the Y coordinate value and the angle θ are detected, a defective shape of the IC chip, that is, a crack or a chip is also detected.

Next, the operation of the pickup device will be described below. Second
As shown in FIG. 2A, the collet 9 moves between the camera 1 (not shown) and the wafer table (not shown), and the IC chip 7 is vacuum-adsorbed and prepared for pickup from the wafer table (not shown). Completed. The position and angle of the wafer table (not shown) or the collet 9 are corrected based on the numerical data of X, Y, and θ taken in by pattern recognition, and the IC chip 7 and the collet 9 are accurately positioned. Then, the wafer fixing block 2 discharges air from the hollow portion 4 and sucks the air near the suction hole 3 through the suction hole 3 to thereby suck the sheet 8 on the upper surface of the wafer fixing block 2.

Next, as shown in FIG. 2B, the push-up mechanism 5 moves upward. Since the sheet 8 is adsorbed on the upper surface of the wafer fixing block 2, the IC chip 7 directly below the collet 9 adhered by the adhesive on the upper surface of the sheet 8 is pressed by the push-up mechanism 5 against the adhesive force on the upper surface of the sheet 8. The sheet is lifted off the sheet 8, adsorbed by the collet 9, picked up, and transferred to the next die bonding step.

As described above, according to the method for illuminating a semiconductor chip of the present invention, the IC chip 7
Pattern recognition can be performed without being affected by the state of the chip 7 surface. Since the wafer fixing block 2 is made of a transparent material, there is no need to move the wafer fixing block 2 up and down when the IC chip 7 is illuminated.

〔The invention's effect〕

The present invention provides a transparent or translucent sheet having an upper surface to which a wafer capable of being divided into IC chips is adhered, and a wafer fixing block for adsorbing and fixing the lower surface of the sheet with a transparent material. A semiconductor light source is provided on the outer periphery of the wafer fixing block, and the divided semiconductor chips are illuminated by the light source through the fixed wafer fixing block and the sheet while the wafer fixing block is literally fixed. 1 on axis
By taking a shadow image of the divided semiconductor chips, pattern recognition including the X-axis coordinate, the Y-axis coordinate, the angle θ, and the shape defect of the divided semiconductor chips is performed,
By positioning the collet and the divided semiconductor chip, illumination for pattern recognition can be performed from below without moving the wafer fixing block up and down, and the illumination method is not affected by the surface condition of the IC chip. It is possible to respond to many models without changing and adjusting. In addition, the pattern can be recognized while the wafer fixing block is fixed, so that there is no loss in the time required to move the wafer fixing block up and down, and no displacement occurs due to moving the wafer fixing block up and down.

As described above, by adopting the semiconductor chip lighting method of the present invention, it is possible to satisfy the requirements of high precision, labor saving, and rationalization of the IC manufacturing process.

[Brief description of the drawings]

FIG. 1 is a side view showing a method of illuminating a semiconductor chip according to one embodiment of the present invention, FIGS. 2A and 2B are side views showing the operation of a pickup device, and FIG. 3 is a configuration diagram of a part of a die bonder. . In the figure, 1 ... video camera 2 ... wafer fixing block 3 ... suction hole 4 ... hollow portion 5 ... push-up mechanism 6 ... light source 7 ... IC chip 8 ... sheet 9 ... collet.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/52

Claims (1)

(57) [Claims] 1. A transparent or semi-transparent sheet having an upper surface adhered to a wafer capable of being divided into semiconductor chips,
A wafer fixing block for sucking and fixing the sheet from below, a light source for illuminating the divided semiconductor chips, a video camera provided on the wafer fixing block, and a push-up mechanism provided on the wafer fixing block; A collet for vacuum-sucking the semiconductor chip, wherein the video camera captures the divided semiconductor chip and performs pattern recognition, thereby detecting the position of the divided semiconductor chip, and using the push-up mechanism. A semiconductor chip lighting method for picking up the divided semiconductor chip and picking up the semiconductor chip from the sheet by using the collet; wherein the wafer fixing block is made of a transparent material, and the light source is provided on an outer peripheral portion of the wafer fixing block. The fixed wafer fixing block, and Through serial sheet, by the divided semiconductor chip illuminated by said light source, imaging the one divided shadow image of the semiconductor chip on the optical axis of said video camera,
A method of illuminating a semiconductor chip, comprising: performing pattern recognition including X-axis coordinates, Y-axis coordinates, an angle θ, and a shape defect of the divided semiconductor chip, and positioning the collet and the divided semiconductor chip.