JPH0288908A - Position detector - Google Patents

Abstract

PURPOSE:To detect a position with high accuracy by reading out two places on partial surface patterns of semiconductor dies selected beforehand in a comparatively higher magnification. CONSTITUTION:A table 2, on the upper face of which a sheet 1 arranged nearly to line up with plural semiconductor dies 3 is placed, is provided to perform a parallel movement and a rotation with the specified angle in accordance with a position control information to be supplied. An optical system 9, by which the 1st and 2nd wiring patterns formed on the semiconductor dies 3 with the distance (l) between the centers of the wiring patterns are picked up as reference patterns then the image is formed, an image pickup camera 4 and an A-D converter 5 are also provided. Further, a pattern matching part 6 to output a position error information for the signal corresponding to the 1st and 2nd wiring patterns and the reference patterns signal PD, and a control part 7 to output the position control information by calculating the position deviation amount based on the position error information are provided. The position is thereby set with high accuracy for even the semiconductor dies having the length of one side longer than 10mm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a position detection device, and more particularly to a position detection device used for positioning a semiconductor die in a die bonding process during semiconductor device assembly.

[Conventional technology]

Conventionally, this type of semiconductor die position detection device uses an optical system 9b with a relatively low magnification to obtain an overall image of a large number of semiconductor dies 3 arranged in a row on a sheet 1, as shown in FIG. 1. Take an image with the imaging camera 4 through the camera. The image signal from the imaging camera 4 was converted into a binary pattern signal and displayed as a binary image 18 on the monitor 17, as shown in FIG.

The binarized image 18 of the semiconductor die 3 is displayed on the monitor 17 even if the size of the semiconductor die 3 changes due to the zoom lens of the optical system 9b.
The position coordinates of the intersection point 22° 23.24, 25, 26.27 between the line segment of the broken line 21 within the field of view of the monitor 17 and the outer edge of the binarized image 18 of the semiconductor die 3 From the center position coordinates of the semiconductor die 3 and the reference line 28.
Calculate the inclination angle θ3 with

The table (not shown) on which the semiconductor die 3 is placed can be moved to align the semiconductor die 3 with the reference position according to the center position coordinates and inclination angle θ1 thus obtained.

[Problem to be solved by the invention]

In the conventional position detection device described above, it is assumed that the binarized image has a size such that at least one semiconductor die can be completely contained within the field of view of the monitor.

Therefore, when dealing with a wide range of targets such as a semiconductor die with a side length of 1 to 10 mm, measures such as changing the magnification of the zoom lens in the optical system to always keep the size of the read pattern constant are necessary. The disadvantage is that it requires

In addition, for semiconductor dies whose length on one side exceeds 10 mm, the magnification of the zoom lens must be set quite low, and the resolution must be set to the minimum precision necessary for the collet to pick up the semiconductor die ( There is a drawback that it becomes impossible to obtain a diameter of about 0.1 mm.

[Means to solve the problem]

The position detection device of the present invention includes a table on which a plurality of semiconductor dies are arranged in a substantially aligned manner, and which performs parallel translation along reference lines of horizontal and vertical axes and rotation by a specified angle according to position control information; The selected first and second wiring patterns among the wiring patterns formed on the surface of the semiconductor die are used as first and second standard patterns, respectively, and the selected semiconductor die surface of the semiconductor die is used as the first and second wiring patterns. and first and second optical systems that form an image with the second wiring pattern as the target center; an imaging camera that captures the formed image and outputs an image signal; and an imaging camera that captures the formed image and outputs an image signal; An A-D converter for converting into a signal compares the binary image pattern signal with standard pattern signals corresponding to the first and second standard patterns, and determines the position between the two pattern positions according to the comparison result. The device includes a pattern matching unit that outputs error information, and a control unit that calculates a positional deviation amount of the binary pattern signal with respect to the standard pattern signal based on the position error information and outputs the position control information. Ru.

〔Example〕

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

FIG. 1 is a block diagram of a first embodiment of the present invention, and FIG. 2 is a side view of the optical system of the first embodiment of FIG.

As shown in FIGS. 1 and 2, a sheet 1 on which a plurality of semiconductor dies 3 are arranged in a substantially aligned manner is placed on the top surface, and the reference lines of the horizontal and vertical axes are aligned according to the supplied position control information. a table 2 that performs parallel translation along and rotation by a specified angle;
The first and second wiring patterns selected from among the wiring patterns imprinted on the surface of the semiconductor die 3 and having the distance l between the centers are used as the first and second standard patterns, respectively. An optical system 9 as a first and second optical system that picks up the semiconductor die surface at a distance l and forms an image, an imaging camera 4 that captures the image and outputs an image signal, and converts the image signal into a digital signal. An A-D converter 5 that outputs a binary image pattern signal, a signal corresponding to the first and second wiring patterns of the binary image pattern signal, and a standard pattern signal corresponding to the first and second standard patterns. a pattern matching unit 6 that outputs positional error information between signals corresponding to the first and second wiring patterns and the standard pattern signal PD by comparing the signals corresponding to the first and second wiring patterns PD; The control unit 7 calculates the positional deviation amount of the signal corresponding to the pattern with respect to the standard pattern signal PD and outputs position control information.

In FIGS. 1 and 2, a sheet 1 is fixed on a table 2, and an enlarged image of the surface of the semiconductor guide 3 on the sheet 1 is captured by an imaging camera 4 through an optical system 9. The signal is digitized by an AD converter 5 to obtain a binary image pattern signal.

Next, FIG. 3 is a pattern image diagram of a standard pattern signal displayed on a monitor to explain the operation of the first embodiment shown in FIG. 1, and FIG. 4 is a pattern image diagram of the first embodiment shown in FIG. FIG. 2 is a pattern image diagram of a binary image pattern signal displayed on a monitor for explaining the operation of FIG.

As shown in FIG. 3, the standard pattern for obtaining the pattern image P 1 + P 2 corresponding to the standard pattern signal PD consists of the first and second wiring patterns having characteristics among the wiring patterns on the semiconductor guide 3. It can be set by the distance l shown in FIG. Note that the distance l can be changed using an adjuster not shown in FIG.

Further, as shown in FIG. 4, pattern images 10 and 11 corresponding to the binary image pattern signal (pattern images 10 and 11 each have two objects in the optical system 9 in FIG. ) is obtained. Note that the broken lines are pattern images p, , P2 corresponding to the standard pattern signal PD.

Returning to FIG. 1 again, the pattern matching section 6 converts the standard pattern signals PD corresponding to the pattern images P, , P2 into binary values corresponding to the first and second wiring patterns in the pattern image 10.11. The image pattern signals are compared to check whether there is a point where the degree of coincidence is higher than a predetermined reference value, and if there is a point, the position of the standard pattern with respect to the first and second wiring patterns of the pattern image 10.11 is determined. Note that the standard pattern signal PD corresponding to the pattern images P, , P2 and the binary image pattern signal corresponding to the pattern image 10.11 are input to the pattern matching section 6 at the same time.

The control unit 7 controls the pattern image p1.in the pattern image 10.11.
From the position p2, the center position coordinates of the semiconductor gouer 3 and the inclination angle θ from the reference line 281 are calculated.

Based on the information on the center position 1 coordinate and the tilt angle θ obtained from the control unit 7, the control unit 7 supplies position control information to the table 2, and moves the position of the table 2.

FIG. 5 is a pattern image diagram in which a binary image pattern signal from a semiconductor die obtained by controlling the position of the table is displayed on the monitor 17.

The control unit 7 follows a preset sequence so that the positions of all the semiconductor dies 3 on the sheet 1 are detected by detecting the positions of the individual semiconductor dies 3 on the sheet 1. Therefore, the table 2 is moved and controlled to perform the above position detection for each semiconductor die 3.

FIG. 6 is a side view of the optical system used in the second embodiment of the invention.

As shown in FIG. 6, two optical systems 9 are used in the second embodiment.
．． This embodiment differs from the first embodiment shown in FIG. 1 in that an imaging camera 4 is separately coupled to each of the two locations to pick up the wiring patterns at two locations on the semiconductor die 3 as respective image signals.

In the second embodiment, since the optical system is separated, the configuration of the optical system is simplified, and the settings of the optical system for selecting the first and second wiring patterns as standard patterns on the surface of the semiconductor guide are easy. It has the advantage of being easier.

〔Effect of the invention〕

As explained above, the present invention reads two parts of a preselected part of the surface pattern of a semiconductor die at relatively high magnification. Even for a semiconductor die having a length of more than 10 parts, the present invention has the effect of enabling more accurate position detection with the same image input time as the conventional method.

[Brief explanation of the drawing]

1 is a block diagram of the first embodiment of the present invention, FIG. 2 is a side view of the optical system of the first embodiment of FIG. 1, and FIG. 3 is a block diagram of the first embodiment of the invention.
1 is a pattern image diagram of a standard pattern signal displayed on a monitor to explain the operation of the first embodiment in the figure; FIG. 4 is a monitor to explain the operation of the first embodiment in FIG. The pattern image diagram of the binary image pattern signal displayed above, FIG. 5 is a pattern image diagram of the binary image pattern signal from the semiconductor guide obtained by controlling the position of the table, displayed on the monitor, and FIG. 7 is a side view of an optical system used in a second embodiment of the present invention, FIG. 7 is a side view of an optical system used in an example of a conventional position detection device, and FIG. 8 shows the operation of the position detection device shown in FIG. It is a pattern image diagram of a binary image pattern signal displayed on a monitor for explanation. DESCRIPTION OF SYMBOLS 1... Sheet, 2... Table, 3... Semiconductor die, 4... Imaging camera, 5... A-D converter, 6...
...Pattern matching section, 7...Control section, 8...
Epi-illuminator, 9.9-. 9b...Optical system, 10.11
...Pattern image corresponding to the binary image pattern signal, 1
2. ...Objective lens, 13...Mirror 14...
Prism, 15... Lens, 16... Condenser lens, 17... Monitor, 18... Binarized image, 19
...Half mirror 20...Coaxial illuminator, 21...
Broken line, 22, 23° 24.25.26.27... Intersection, 28-. 28b...Reference line, P1 * P2.
・Pattern image corresponding to standard pattern signal, PD...
・Standard pattern signal, θ. θ1...Inclination angle.

Claims (1)

[Claims] a table on which a plurality of semiconductor dies are arranged in a substantially aligned manner on an upper surface, and which performs parallel translation along reference lines of horizontal and vertical axes and rotation at a specified angle according to position control information; The selected first and second wiring patterns among the selected wiring patterns are used as first and second standard patterns, respectively, and the selected semiconductor die surface of the semiconductor die is set as a target for the first and second wiring patterns. first and second optical systems that form an image as a center; an imaging camera that captures the formed image and outputs an image signal; and A-D conversion that converts the image signal into a binary image pattern signal. a pattern matching unit that compares the binary image pattern signal with standard pattern signals corresponding to the first and second standard patterns and outputs position error information between the positions of both patterns according to the comparison result; A position detection device comprising: a control section that calculates a positional deviation amount of the binary pattern signal with respect to the standard pattern signal based on the position error information and outputs the position control information.