TWI421962B - Light emitting diode wafer sorting method - Google Patents

Description

Light-emitting diode wafer sorting method

The present invention relates to the sorting of wafer dies, and more particularly to a method of sorting a light emitting diode wafer.

Each grain on the wafer or the process relationship will have a good quality. To ensure that the selected die is qualified, electrical testing is usually performed to detect the electrical and optical properties of each die. Or use the image to identify whether there is any flaw in the appearance, and then select the qualified crystal grains.

There are two methods for sorting crystal grains: one is that the detection and sorting are performed by the same machine, and its advantages are reliable, but the speed is very slow, and the productivity is low; the second is to divide the detection and sorting into two. The machine is completed, that is, each die on a wafer is first detected by a spot test device, and classified according to different characteristics of each die, and a row-column is generated according to the row (Row- The column, RC) mode marks the output file of each die position, and then a sorting device (sorter) controls a pick-up device to sort and sort the dies belonging to the same level but dispersed everywhere according to the output file. Therefore, the picking device often needs to perform a jump operation to pick up the next die. However, the above-mentioned sorting method of marking each crystal grain position in a row-column (R-C) manner and provoking the next crystal grain by jumping action is liable to cause sorting errors due to the following factors:

1. In the process of crystal separation between the two steps of detection and sorting, chip epitaxy fragmentation, partial fragmentation or partial defects may occur, so that the actual crystal grain dispersion and the data stored in the sorting machine may occur. Inconsistent, resulting in difficulty in sorting.

2. The grain size is small and the spacing between the crystals is small, and when the crystal grains are selected and the thimble is lifted from the bottom to the bottom and adhered to the blue film as the support as the support, the separation and removal action is easy to involve the blue film and cause a little Shifting causes positional changes of other unselected dies, especially in the addition of hopping actions, which will increase the probability of sorting errors.

3. The grain is marked in a row-column (RC) manner, and accordingly it is a provocation. Although it is a simple and fast positioning and sorting method, it cannot provide sufficient accuracy to improve the provocation accuracy. .

In summary, it can be seen that although the grain is marked by the row-column (R-C) method before being sorted, there is no immediate monitoring, comparison, review, etc., which leads to subsequent sorting errors.

In view of this, the main object of the present invention is to provide a method for sorting a light-emitting diode wafer, which has the advantages of improving the accuracy of grain sorting and reducing the occurrence of errors.

In order to achieve the above object, the method for sorting a light-emitting diode wafer provided by the present invention comprises: generating a feature grain coordinate and a grain distribution wafer map, wherein the grain distribution wafer map records characteristic grain Position and indicate the characteristic grain position by a special mark; receive the grain distribution wafer map and the wafer by using a sorting device, and an image recognizer searches for each crystal according to the data of the die distribution wafer map The position of the grain, when the feature grain is covered in the pre-viewable range of the image identifier, the feature grain coordinates are read in and compared with the grain distribution wafer map, and if the visual recognition is a special mark, the feature is confirmed The actual position of the die coincides with the position of the feature grain recorded on the grain distribution wafer map.

In another method, after the grain distribution wafer map is generated, the grain distribution wafer map records the position of the characteristic grain, performs the wafer scanning, and generates a wafer die coordinate; and then compares the grain distribution a wafer map and the wafer die coordinates to confirm the grain position, and the wafer map and the feature grain coordinates of the grain distribution, if the special mark position and the feature grain position match, a sorting device is used Perform grain sorting.

In another method, a single measuring device is used to detect each die of the wafer, and a grain distribution wafer map of each die position is recorded by a first set of relative coordinates; then wafer scanning is performed and a wafer crystal is generated. a grain coordinate, wherein the die coordinates of the wafer are recorded with respective die positions, and the die positions are recorded and stored in a second set of relative coordinates and an absolute coordinate; and then the first set of relative coordinates and the second set are compared The grain position recorded relative to the coordinates, if the two errors are within a predetermined range, the grain position is recorded by the sorting device with the absolute coordinate recorded grain position.

The first figure shows a schematic diagram of a wafer after dicing, the wafer 100 includes a plurality of dies 101, and the dies 101 are distinguished by normal crystal grains 101a and non-functional dies (see Alignment Key) 101b, wherein the normal crystal grains 101a have different degrees of electrical and optical characteristics due to process relationships, and the characteristic crystal grains 101b are dispersed in the respective normal crystal grains 101a. In order to improve the correctness and reliability in the sorting process of the foregoing die 101, the present invention provides a sorting method of the following preferred embodiment: please cooperate with the comparison flowchart (1) shown in the second figure, wherein the characteristic crystal The formation of the particles 101b is performed by using a photomask during the fabrication of the wafer 100. In the wafer 100 process of the embodiment, a feature grain coordinate 200 is simultaneously generated, as shown in the third figure. That is, the preset position of the feature crystal grain 101b is indicated.

Then, each of the crystal grains 101 on the wafer 100 is subjected to characteristic detection including electrical and optical characteristics, and is classified according to the measured different characteristics of each crystal grain, and according to the probe. To generate a grain distribution wafer map 300, as shown in the fourth figure, the grain distribution wafer map 300 records the position of the normal crystal grain 101a and the position of the characteristic crystal grain 101b in a row-column (RC) manner. In the embodiment, the feature crystal 101b is represented by a cavity, and the black square indicates a void. It should be noted that, in addition to the voids representing the characteristic crystal grains 101b, a specific level of crystal grains from the graded crystal grains is selected as the characteristic crystal grains. In the embodiment, the probe card is exemplified by a probe card, but not limited thereto.

The die distribution wafer map 300 will be transmitted to a sorter having an image recognizer, the sorting device simultaneously receiving the wafer 100, and then the image recognizer will distribute the wafer map according to the die 300 data to find the position of each die 101, and after confirming the position, control a picking device (such as a vacuum suction robot) to perform the die 101 provocation. Under normal circumstances, the die 101 will be properly sorted out, and when the feature die 101b is included in the predictable range of the image recognizer, the sorting device will read the feature die coordinates 200. And performing a pattern comparison with the die distribution wafer map 300. If the visual recognition is a hole, the actual position of the feature die 101b and the position of the feature die 101b recorded by the die distribution wafer map 300 are confirmed. In agreement, this confirmation action helps to detect whether the grain 101 sorting is correct in time. In the case where the above position is consistent, the pick is correct. Conversely, if the actual position of the die 101 does not match the stored data during the separation process. When the image recognizer is identified as a non-void, and a normal die 101a indicates that the sorting is incorrect, the subsequent sorting action should be stopped immediately.

The die distribution wafer map 300 of the above embodiment is formed by the spotting device to form an output file, and then transmitted to the sorting device; of course, the die distribution wafer map 300 can also be in the form of a data. The way the network is transmitted is directly transmitted to the sorting device.

The above sorting method is to re-confirm the ratio of the positions of the characteristic crystal grains 101b during the provocation process of the crystal grain 101, and has the effect of finding a problem in time to interrupt the sorting action. In addition, the above-mentioned characteristic die coordinates 200 are received by the sorting device in advance, but they may also be stored in the implement other than the sorting device, and then read by the sorting device. In addition, the point measurement device, the sorting device, the image recognizer, and the capture device in the embodiment are both existing devices, and are not described herein.

It is also worth mentioning that the feature die coordinates 200 of the above embodiment are separately generated during the fabrication process of the wafer 100, and the die distribution wafer map 300 is generated by the spotting device detecting the wafer, however, the feature The generation of the die coordinates 200 and the die distribution wafer map 300 can also be generated as shown in the fifth figure when the spotting device detects the wafer. It is noted that the feature die coordinates 200 and the die distribution wafer map 300 can be stored separately in a separate manner, and the feature die coordinates 200 can also be stored in the die distribution wafer map 300.

Here, the feature die coordinates 200 and the die distribution wafer map 300 are generated by the spotting device to form an output file, and then transmitted to the sorting device; of course, the feature die coordinates 200 and the die distribution wafer map The 300 can also be transmitted as a data to the sorting device by means of network transmission.

The present invention further provides another sorting method. For example, please cooperate with the comparison flowchart (2) shown in FIG. 6 to include a feature grain coordinate 200 and a grain distribution wafer map in the whole alignment process. 300 and a wafer die coordinate 400 generated by scanning, wherein the feature die coordinates 200 and the grain distribution wafer map 300 are generated in the same manner as the above embodiment, and of course, the feature die coordinates 200 are also obtained. It is generated when the spotting device detects the wafer. The wafer die coordinates 400 are created and obtained by scanning the wafer 100 by using a scanning device with image scanning and identification functions after the die distribution wafer map 300 is completed.

In the comparison process, in the comparison process, the step of comparing the wafer distribution wafer map 300 with the wafer die coordinate 400, that is, the nest pattern I in the sixth figure, is firstly performed to confirm the position of the die 101 and appropriately compensate. Corresponding to the position error of the die 101, when the confirmation error is still within a predetermined range, the alignment of the die distribution wafer map 300 with the feature die coordinate 200 is performed, that is, the sixth figure. In the middle of the step of comparing Figure II, the comparison intention is to use the confirmation of the position of the feature die 101b to improve the alignment accuracy, if the cavity location of the die distribution wafer map 300 and the feature die 101b of the feature die coordinates 200 If the position is consistent, it means that the starting point of the grain sorting is set correctly, and the subsequent sorting operation can be carried out smoothly. Otherwise, the correction can be made in time.

Here, the die distribution wafer map 300 is generated by the spotting device to form an output file, and then transmitted to the sorting device; of course, the die distribution wafer map 300 can also be in the form of a data. The way of transmission is directly transmitted to the sorting device.

In this embodiment, the scanning device is part of the sorting device, but the scanning device may also be a separate device located between the spotting device and the sorting device, as shown in the seventh figure. c) The output of the wafer die coordinates 400 is obtained independently of another device (ie, a scanning device) other than the sorting device, which makes the wafer more flexible in the detection and sorting process.

Here, the wafer die coordinates 400 are generated by the scanning device to form an output file, and then transmitted to the sorting device; of course, the wafer die coordinates 400 can also be transmitted as a data in the form of a network. The way is directly transmitted to the sorting device.

The comparison process shown in the second figure above differs from the comparison process shown in the sixth and seventh figures in that the former is found in the process of grain sorting provocation by the confirmation of the location of the feature grain 101b. The problem is related to the purpose of interrupting the sorting action; the latter two are compared by a two-stage comparison to confirm whether the starting point of the grain sorting is set correctly or not. However, in any case, the present invention can achieve the correct sorting and reduce the effect of errors.

The method for sorting the light-emitting diode wafer of the present invention may be the steps disclosed in the following embodiments: please cooperate with the comparison flowchart (4) shown in the eighth figure, wherein the generation of the grain distribution wafer map 500 is the same. The wafers are generated by detecting a plurality of grains of the wafer through a spot measuring device. The grain distribution wafer map 500 records the positions of the respective grains in a first set of relative coordinates.

Then, a scanning device having an image scanning and identification function scans each of the crystal grains on the wafer, and simultaneously generates a wafer die coordinate 600, and the scanning device is a part of the sorting device, and the wafer die Coordinates 600 record the position of each die, and each die position is simultaneously recorded and stored in a second set of relative coordinates and an absolute coordinate. It must be noted that the second set of relative coordinates is generated by: The information provided by the group relative to the coordinate control scanning device changes the image recognition position to the top of the predetermined crystal grain, and the instantaneous image information of the scanning device compensates for the error of the corresponding crystal grain position to generate the second group of relative coordinates.

And then performing a comparison between the first set of relative coordinates and the recorded position of the second set of opposite coordinates, that is, the step of comparing the I in the eighth figure, if the error between the two is within a preset range, the score The device selects the die position recorded by the absolute coordinate to perform grain sorting. Otherwise, if the error between the first set of relative coordinates and the recorded position of the second set of opposite coordinates exceeds the preset range, the correction is performed in time or Suspend the sorting action.

Here, the grain distribution wafer map 500 is generated by the spotting device to form an output file, and then transmitted to the sorting device; of course, the grain distribution wafer map 500 can also be formed into a form of data. The way of transmission is directly transmitted to the sorting device.

The scanning device of the above embodiment is part of the sorting device, but the scanning device can also be a separate device located between the spotting device and the sorting device.

The above description is only for the preferred embodiments of the present invention, and the equivalent structures and manufacturing methods of the present invention and the scope of the patent application are intended to be included in the scope of the present invention.

100. . . Wafer

101. . . Grain

101a. . . Normal grain

101b. . . Characteristic grain

200. . . Characteristic grain coordinates

300. . . Grain distribution wafer map

400. . . Wafer die coordinates

500. . . Grain distribution wafer map

600. . . Wafer die coordinates

The first picture is a schematic diagram of a general wafer.

The second figure is a comparison flowchart (1) of a preferred embodiment of the present invention.

The third figure is a schematic diagram of a feature grain coordinate of a preferred embodiment of the present invention.

The fourth figure is a schematic diagram of a grain distribution wafer map in accordance with a preferred embodiment of the present invention.

The fifth figure is another alignment flowchart of the above preferred embodiment of the present invention, illustrating that the feature die coordinates and the die distribution wafer map system are simultaneously generated.

Figure 6 is a flow chart (2) of a comparison of preferred embodiments of the present invention.

Figure 7 is a flow chart (3) of a comparison of preferred embodiments of the present invention.

The eighth figure is a comparison flowchart (4) of a preferred embodiment of the present invention.

200. . . Characteristic grain coordinates

300. . . Grain distribution wafer map

Claims (17)

A method for sorting a light-emitting diode wafer, comprising the steps of: obtaining a feature grain coordinate and generating a grain distribution wafer map, wherein the grain distribution wafer map records the position of the characteristic grain and is a special The mark indicates the feature grain position; the grain distribution wafer map and the wafer are received by a sorting device, and an image recognizer searches for the die position according to the data of the die distribution wafer map, in the image When the feature dies are covered in the predictable range, the feature grain coordinates are read and compared with the grain distribution wafer map. If the visual identification is a special mark, the actual position of the feature dies is confirmed. The position of the characteristic crystal grains recorded on the grain distribution wafer map is consistent. The method for sorting a light emitting diode according to claim 1, wherein the sorting device continues to pick crystal when the actual position of the feature grain is confirmed to coincide with the position of the characteristic grain recorded by the grain distribution wafer map. grain. The method according to claim 1, wherein the characteristic die coordinates and the die distribution wafer map are generated by a spotting device detecting a wafer. The method according to claim 1, wherein the characteristic die coordinates are separately generated in a wafer fabrication process, and the die distribution wafer map is generated by a spot measuring device detecting a wafer. . The method of sorting a light emitting diode according to claim 1, wherein the special mark is a void pattern indicating a feature grain position. The method of sorting a light emitting diode according to claim 1, wherein the special mark is a position representing a predetermined level of the die. The method of claim 2, wherein the characteristic die coordinate is received with the die distribution wafer map for the sorting device. The method according to claim 1, wherein the characteristic die coordinate is read from outside the sorting device. A method for sorting a light-emitting diode wafer, comprising the steps of: generating a feature grain coordinate and a grain distribution wafer map, wherein the grain distribution wafer map records the position of the characteristic grain and is marked with a special mark Representing the characteristic grain position; performing wafer scanning and generating a wafer die coordinate; distributing the wafer map and the wafer die coordinates to confirm the grain position, and comparing the grain distribution crystal The circular map and the characteristic grain coordinates, if the special mark position coincides with the feature grain position, the grain sorting is performed by a sorting device. The method for sorting a light-emitting diode wafer according to claim 9 is to scan the wafer by a scanning device having an image scanning and identification function, and the scanning device is a part of the sorting device. The method for sorting a light-emitting diode wafer according to claim 9, wherein the wafer is scanned by a scanning device having an image scanning and identification function, and the scanning device is located in the spot measuring device and the sorting device. between. The method of claim 2, wherein the characteristic die coordinates and the die distribution wafer map are generated by a spotting device detecting a wafer. The method according to claim 9, wherein the characteristic die coordinates are separately generated in a wafer fabrication process, and the die distribution wafer map is generated by a spot measuring device detecting a wafer. . The method of claim 2, wherein the special mark is a void pattern representing a feature grain position. The method of sorting a light emitting diode according to claim 9, wherein the special mark is a position representing a predetermined level of the die. A method for sorting a light-emitting diode wafer, comprising the steps of: detecting a die of a wafer by using a point measuring device, and generating a grain distribution wafer map, wherein the grain distribution wafer map is in a first group relative Coordinates record each die position; perform wafer scanning and generate a wafer die coordinate, the wafer die coordinates record each die position, and the die position is a second set of relative coordinates and an absolute coordinate Mode record storage; if the error between the first set of relative coordinates and the second set of relative coordinates is recorded, if the error between the two is within a preset range, a sorting device records the die position with the absolute coordinate Perform grain sorting. The method for sorting a light-emitting diode according to claim 16, wherein the information provided by the first set of relative coordinates is used to control a scanning device to change the image recognition position to above the predetermined die, and the image information of the scanning device is compensated. The error of the corresponding grain position, and accordingly the second set of relative coordinates.