JPH0729855A - Expanding method of semiconductor wafer - Google Patents

Abstract

PURPOSE:To obtain an expanding method which can expand the interval between semiconductor chips with good accuracy and simply in the manufacture of a semiconductor integrated circuit. CONSTITUTION:In an expanding method in the manufacture of a semiconductor integrated circuit, a semiconductor wafer 1 which has been fixed and bonded to an elastic sheet 2 is cut along dicing lines 6,...6, and each interval between semiconductor wafer chips 1',...1' which have been 'diced is then expanded by stretching the sheet 2. The expanding method is featured in such a way that the sheet is stretched until the diced semiconductor chips 1',1' on both rnds reach a prescribed interval 7, and the wafer ships l', 1' on both ends are measured by an optical sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expanding method capable of accurately and easily expanding the distance between semiconductor wafer chips when manufacturing a semiconductor integrated circuit.

[0002]

2. Description of the Prior Art Prior to manufacturing a semiconductor integrated circuit, a semiconductor wafer chip such as a diced IC or FET is transferred to a lead frame or package and mounted by a bonding material such as solder, gold or resin. It is necessary to dice a semiconductor wafer fixed on a tape having elasticity and to stretch the tape so that the distance between the diced wafer chips becomes a predetermined size.

3A and 3B are views for explaining a conventional expanding method. FIG. 3A is a vertical sectional view before expanding, and FIG. 3B is a sectional view after expanding. is there. An elastic sheet 2 is fixed to the ring 3, and the wafer 1 fixed on the sheet 2 is cut in the vertical and horizontal directions according to the dicing lines 6 ... The ring 3 is pulled in the axial direction of the cylindrical tube 4 arranged inscribed therein, and the wafer chips 1 ′ ... 1 ′ cut as shown in FIG. 7 ... 7 is opened. The intervals 7 ... 7 are determined by the distance of the pulled ring 3, and the position of the ring 3 is optically controlled by the laser light 5 irradiated on the outer circumference of the cylindrical tube 4.

[0004]

The size of wafer chips 1 '... 1'to be diced is small in the case of FET and large in the case of LSI. When this is expanded by the conventional method, when the wafer chip is small and the number of dicing lines 6 ...
········································· 7 becomes narrower, on the contrary, when the wafer chip is large, the interval 7 ... That is, in the conventional method, the intervals 7 ... 7 obtained by expanding change depending on the number of dicing lines 6 ... 6 to be cut, so it is necessary to adjust after expanding once. It was difficult to make it constant regardless of the number. Therefore, an object of the present invention is to provide a method for expanding a semiconductor wafer that solves the above problems.

[0005]

According to a method of expanding a semiconductor wafer according to the present invention, a semiconductor wafer fixed on an elastic sheet is diced at the time of manufacturing a semiconductor integrated circuit, and then the above-mentioned wafer is diced. -An expanding method of expanding the distance between the diced semiconductor wafer chips by stretching the sheet, characterized in that the sheet is expanded until the wafer chips at the both ends of the diced have a predetermined distance, The wafer chip is measured by the optical sensor.

In the above method, it is preferable to keep the ambient temperature at about 65 ° C. when the elastic sheet is stretched and the distance between the semiconductor wafer chips fixed thereon is widened.

[0007]

If the number of dicing lines and the distance between adjacent dicing lines are known, the positions of the wafer chips at both ends after expansion are determined. The distance can be uniquely determined by stretching the pitch. That is, since the position of the wafer chip is directly measured by the laser light, the interval can be determined more accurately than before. Further, since the sheet is expanded while the ambient temperature is maintained at about 65 ° C., it is possible to suppress variations in the intervals of the semiconductor wafer chips due to the positions between the sheets or within the sheet as much as possible.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. 1A and 1B are views showing a configuration of an embodiment according to the present invention. FIG. 1A is a vertical sectional view before expanding and FIG. 1B is a vertical sectional view after expanding. Note that the same elements as those in FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted. In FIG. 1, the upper surface of the sheet 2 is irradiated with laser light 5 and 5 at a predetermined interval from a detection device (not shown), and the time when the reflected light returns is measured. As shown in FIG. 2B, when the wafer chips 1 ', 1'at both ends on the sheet are pulled to both sides and irradiated with the laser light 5, 5, the time during which the reflected light returns is the thickness thereof. Since it is shortened by that amount, it can be measured by the optical sensor that the wafer chips 1 ', 1'at both ends have moved to a predetermined interval. Sheet 2 is a vinyl chloride V-made by Nitto Denko.
8-M was used.

2A and 2B are views for explaining an embodiment of the present invention. FIG. 2A is a plan view before expanding and FIG. 2B is a plan view after expanding. A GaAs wafer 1 having a diameter of 3 inches (76 mmφ) fixed to the sheet 2 is laid along a vertical and horizontal dicing line 6
... 6 was cut and the sheet 2 was expanded by 150% while pulling down the ring 3 having an inner diameter of 150 mm. To expand the wafer chips 1'a and 1'b on both ends to 1 "a and 1" b, the optical sensor method described in FIG. 1 was used. In order to improve the accuracy of expanding, the same measurement was performed on the wafer chips 1 ″ c and 1 ″ d on both ends in the vertical direction.

Further, the dimension of the sheet 2 that is stretched may change depending on the ambient temperature, and the sheet 2 may vary depending on the position between sheets or within the sheet. Therefore, expanding was performed in the range of 65 ± 2 ° C. As a result, 1mm x
1 mm wafer chip 1 "... 1" spacing 7 ... 7
Is 0.5 mm, and the wafer chip 1 ″ ... By a collet (not shown) in the die bonding process.
It was possible to secure a space for transporting 1 "to the lead frame or the package.

[0011]

As described above, according to the present invention, the positions of the wafer chips at both ends after expanding are determined if the number of dicing lines and the adjacent intervals are known. The distance can be uniquely determined by stretching the sheet while measuring. Further, since the position of the wafer chip is directly measured by the laser light and the sheet is expanded while keeping the ambient temperature at about 65 [deg.] C., the interval can be determined more accurately than before.

[Brief description of drawings]

1A and 1B are views showing a configuration of an embodiment according to the present invention, in which FIG. 1A is a vertical sectional view before expanding and FIG. 1B is a vertical sectional view after expanding.

FIG. 2 is a diagram for explaining an embodiment of the present invention,
FIG. 7A is a plan view before expanding, and FIG. 7B is a plan view after expanding.

3A and 3B are views for explaining a conventional expanding method, wherein FIG. 3A is a vertical sectional view before expanding and FIG. 3B is a sectional view after expanding.

[Explanation of symbols]

 1: Wafer 1 ′, 1 ″: Wafer chip 2: Sheet 3: Ring 4: Cylindrical tube 5: Laser light 6: Dicing line 7: Interval

Claims (3)

[Claims] 1. When manufacturing a semiconductor integrated circuit, a semiconductor wafer fixed on an elastic sheet is diced,
Thereafter, the sheet is stretched to expand the distance between the diced semiconductor wafer chips, and the sheet is stretched until the diced wafer chips at both ends have a predetermined distance. Semiconductor wafer expanding method. 2. The method of expanding a semiconductor wafer according to claim 1, wherein the distance between the wafer chips at both ends is measured by an optical sensor. 3. The semiconductor wafer extract according to claim 1, wherein the ambient temperature is maintained at about 65 ° C. when the elastic sheet is stretched and the interval between the semiconductor wafer chips fixed thereon is widened. How to pan.