JPS6146053B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for recognizing the position of a semiconductor element in a method for dropping a solution onto a semiconductor element.

(b) Prior Art and Problems As is well known, when a semiconductor memory device is irradiated with alpha rays, written information is lost. Therefore, various measures have been taken to solve the above problem.

One of the countermeasures against this problem is to mount the elements of the semiconductor memory device (hereinafter simply referred to as chips) in a predetermined package, and then apply resin onto the chips.

To apply the resin, the position of the chip mounted on the package is recognized, and the resin liquid dropping tool is moved to that position to drip the resin liquid onto the chip.

However, it is not always easy to recognize the location of the chips mounted on the package. That is, the chip is fixed onto the package using a wax material, usually consisting mainly of gold (Au), and the wax material spreads around the chip. Moreover, since there is not much difference between the binary signal of the reflected light from the wax material surface and the binary signal of the reflected light from the chip surface, it is not possible to clearly distinguish between the two. Therefore, there is a problem in that it is difficult to accurately detect the position of the chip, and therefore it is difficult to automatically apply the above-mentioned resin liquid.

(c) Object of the Invention An object of the present invention is to solve the above-mentioned problems and provide a chip position recognition method that facilitates chip position recognition.

(d) Structure of the Invention The feature of the present invention is to take advantage of the fact that the memory cell part is easily distinguishable from other parts in binary data.
A region where a certain number or more of consecutive binary data indicating that the amount of reflected light of the light irradiated on the semiconductor element is low is detected, and a binary value is generated at the outer edge of the region. The purpose of this method is to recognize the position where the converted data changes as the periphery of the memory cell portion, and to determine the center position of the chip from the position of this periphery and the mutual positional relationship of the memory cell portion with respect to the chip which has been stored in advance.

(e) Examples of the invention The present invention will be explained below by way of an example.

FIG. 1 is a system configuration diagram showing the main parts of the above embodiment, where 1 is a sample to be processed, 2 is a chip, 3 is a package, 4 is a stage, 5 is a TV camera, 6 is a lens system, and 7 is a solution droplet. Tool, 8 is drive unit, 9 is
TV camera driver, 10 is a TV monitor, 11 is a position detection circuit, 12 is a control system, 13 is a storage device, 1
4 is an arithmetic circuit.

In this embodiment, before starting the process of applying the resin liquid to the chip, the top of the chip 2 is first imaged by the TV camera 5 using the lens system 6, and the chip 2 is displayed on the TV monitor 10 via the TV camera driver 9. A binarized image (see Figure 2) is displayed. In the binarized image displayed on the screen of the TV monitor 10 at this time, as described above, it is difficult to clearly distinguish between the image of the chip 2 and the wax material 15 spread around it.

In contrast, the inventors of the present application have discovered that the effective reflectivity of the memory cell portion 3 of the chip 2 is lower than that of other surrounding portions, and that by appropriately selecting the slice level, the memory cell portion 3 of the chip 2 has a It has been found that the cell portion 3 can be easily identified. This is because the wiring width in the memory cell portion 3 is narrower than in other parts of the chip 2, and the wiring pattern is formed densely, so that the unevenness is more severe than in other parts. Therefore, the irradiated light is diffusely reflected and the amount of light incident on the TV camera 10 is reduced, resulting in the same result as if the reflectance had become low.

The present invention attempts to recognize the position of the memory cell section 3 by utilizing this phenomenon.
In the captured image data, the signal level of the portion corresponding to the memory cell portion 3 is lower than that of other surrounding portions. Therefore, by binarizing this at an appropriate slice level, the binarized data can be made to have continuous "0" in the memory cell section 3 and "1" around the memory cell section 3. can.

Therefore, if "0" continues over a certain length in the binary data of the chip 2, that area can be recognized as the memory cell section 3. It is determined in accordance with the type, and in the binarized data obtained by imaging the chip 2, an area where "0" continues beyond the above-mentioned standard length is detected, and this is stored in the memory cell section 3. recognized as By detecting the position where the binary data changes from "0" to "1" at the outermost periphery of this area, the position of the periphery of the memory cell section 3 can be recognized.

Therefore, first, two cursors 16 and 17 are drawn on the TV monitor 10 in the vertical and horizontal directions, and these are made to coincide with the four sides of the memory cell section 3 as shown in the figure. The positions of the cursors 16 and 17 at this time are detected by the position detection circuit 11, and this position data is stored in the storage device 13 via the control system 12.

Next, the non-binarized image of chip 2 is displayed on the TV again.
It is displayed on the monitor 10. This time, the periphery of chip 2 can be clearly identified, so the cursors 16 and 17 are aligned with the four sides of chip 2, respectively. The positions of these cursors 16 and 17 are also the same as before.
It is stored in 3. From these two positional data, the mutual positional relationship of the memory cell section 3 with respect to the chip 2 can be obtained.

With the above steps, preparations for detecting the position of the chip are completed.

In order to apply the resin liquid to the chip 2, the memory cell section 3 is imaged by the TV camera 5, the video signal is binarized by the position detection circuit 11, and from this binarized data, a low level of light intensity is detected. Find an area in which the length of consecutive "0"s indicating that 0 exceeds a preset reference length. Since this area is the memory cell section 3 as mentioned above, the binary data changes from "0" to "1" at the outermost periphery of this area.
Detects the position that changes. As described above, the positional coordinates of the periphery of the memory cell section 3 have been detected.

These position coordinates are sent to the arithmetic circuit 14, which performs a correction calculation using the two sets of position data read out from the storage device 13 based on commands from the control system 12, and calculates the center position of the chip 2. . Then, calculate the difference with the current position coordinates of the TV camera 5,
Output as a correction amount. Based on this correction amount, the drive section 8 moves the solution dropping tool 7 to a position directly above the center of the chip 2.

After this, drop the resin liquid as usual and chip 2.
The surface is coated with resin.

As described above, in this embodiment, the memory cell part 3 is detected by utilizing the fact that the effective reflectance of the memory cell part in the chip is different from other parts, and the memory cell part 3 is fixed on the package with wax material. The position of the chip 2 can be clearly detected.

(f) Effects of the Invention As explained above, according to the present invention, the position of the chip can be easily recognized and the resin liquid can be applied automatically.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing the main parts of an embodiment of the present invention, and FIG. 2 is a diagram for explaining the position detection method of the above embodiment. In the figure, 1 is a sample to be processed, 2 is a semiconductor element, 3 is a package, 5 is a TV camera, 6 is a lens system, 7 is a solution dropping tool, 8 is a drive unit, and 10 is a
11 is a position detection circuit, 12 is a control system, 13 is a storage device, and 14 is an arithmetic circuit.

Claims (1)

[Claims] 1 The mutual positional relationship of the memory cell portion formed on the surface of the semiconductor element with respect to the semiconductor element and the reference length serving as the recognition standard of the memory cell portion are stored in advance, and the semiconductor element is fixed to the package with wax material. When performing positioning, in the binarized data of the captured image of the semiconductor element to be positioned, data indicating that the amount of reflected light of the light irradiated to the semiconductor element is at a low level continues beyond the reference length. A region is detected, the detected region is recognized as a memory cell section, and a position where the binary data changes between the recognized memory cell section and other parts around it is determined in the memory cell section. A method for recognizing the position of a semiconductor element, characterized in that the position of the center of the semiconductor element is determined from the recognized position of the peripheral edge of the memory cell portion and the mutual positional relationship.