阅读说明：本技术 探针自我校正系统及其方法 (Probe self-calibration system and method thereof ) 是由 李茂杉 余昱熙 于 2019-01-17 设计创作，主要内容包括：一种探针自我校正方法,其步骤包含有：更换一探针卡,该探针卡具有至少一探针,该探针具有一针尖；采集一水平位置图像,一图像采集单元采集该探针卡的水平位置图像,该水平位置图像具有至少一针尖的图像；计算水平差异量,由一控制单元计算该水平位置图像中的该针尖的水平差异量,该控制单元具有该探针卡更换前的该探针卡的位置参数,该位置参数包含一水平位置参数及一垂直位置参数；以及补正水平测量位置,该控制单元结合该水平位置参数与该水平差异量成为补正后的水平位置参数,再由该控制单元补正该探针卡的水平测量位置。(A probe self-calibration method includes the steps of: replacing a probe card, wherein the probe card is provided with at least one probe, and the probe is provided with a probe point; acquiring a horizontal position image, wherein an image acquisition unit acquires the horizontal position image of the probe card, and the horizontal position image is provided with an image of at least one needle point; calculating the horizontal difference, and calculating the horizontal difference of the needle point in the horizontal position image by a control unit, wherein the control unit is provided with position parameters of the probe card before the probe card is replaced, and the position parameters comprise a horizontal position parameter and a vertical position parameter; and correcting the horizontal measurement position, wherein the control unit combines the horizontal position parameter and the horizontal difference to form a corrected horizontal position parameter, and then the control unit corrects the horizontal measurement position of the probe card.)

1. A probe self-calibration method includes the steps of:

replacing a probe card, wherein the probe card is provided with at least one probe, and the probe is provided with a probe point;

acquiring a horizontal position image, wherein an image acquisition unit acquires the horizontal position image of the probe card, and the horizontal position image is provided with an image of at least one needle point;

calculating the horizontal difference, and calculating the horizontal difference of the needle point in the horizontal position image by a control unit, wherein the control unit is provided with position parameters of the probe card before the probe card is replaced, and the position parameters comprise a horizontal position parameter and a vertical position parameter; and

correcting the horizontal measurement position, combining the horizontal position parameter and the horizontal difference to obtain a corrected horizontal position parameter, and correcting the horizontal measurement position of the probe card by the control unit.

2. The probe self-calibration method of claim 1, wherein the horizontal position parameter comprises an X-axis position parameter, a Y-axis position parameter, or an angular position parameter; the horizontal difference amount includes an X-axis position difference amount, a Y-axis position difference amount, or an angular position difference amount.

3. The probe self-calibration method of claim 1, further comprising a step of calculating a vertical difference, wherein the control unit controls the probe card to approach a load cell in a vertical direction, and if a change in the value of the load cell is detected, the control unit determines that the probe is in contact with the load cell, and the control unit calculates the vertical difference of the probe accordingly.

4. The probe self-calibration method of claim 1, further comprising a step of calculating a vertical difference, wherein the control unit controls the probe card to approach a reference pad in a vertical direction, the image capturing unit captures an image of the probe tip and transmits the image to the control unit, when the control unit detects a relative displacement of the probe tip in a horizontal direction, the control unit determines that the probe tip has contacted the reference pad, and the control unit calculates a difference between the vertical position and the vertical position parameter at the moment to be a vertical difference.

5. The probe self-calibration method according to claim 3 or 4, further comprising a step of correcting a vertical measurement position by the control unit combining the vertical position parameter and the vertical difference amount into a corrected vertical position parameter, and correcting the vertical measurement position of the probe card by the control unit.

6. The probe self-calibration method of claim 1, wherein the image capturing unit further comprises a reference mark, and the horizontal difference is a difference between positions of the tip and the reference mark.

7. The probe self-calibration method of claim 6, wherein the fiducial mark is a cross-hair or a fiducial mark.

8. A probe self-calibration system applied to at least one probe card comprises:

a carrying platform;

a control unit;

the mobile unit is arranged on the carrying platform, is electrically connected with the control unit and is controlled by the control unit to carry the probe card; and

and the image acquisition unit is electrically connected with the control unit and acquires an image of the probe card.

9. The probe self-calibration system of claim 8, wherein the image capture unit is located above, below, or to one side of the probe card; the carrier has a load cell or a reference pad.

10. The probe self-calibration system of claim 8, wherein the image capturing unit further comprises a fiducial mark, the fiducial mark being a cross-hair or a fiducial mark.

Technical Field

A system and method for self-calibrating a probe, and more particularly, to a system and method for calibrating a probe card to correct a measurement position by obtaining a difference from an image.

Background

In the semiconductor industry, chips, wafers, or panels are subjected to electrical inspection at various stages during the fabrication process. In the conventional electrical inspection method, an inspection machine having a probe card is used to inspect a panel, a chip or a wafer placed on a carrier.

During the inspection, the probe tip of the probe card contacts the position to be inspected of the object to be inspected, and the inspection result is transmitted back to the control unit of the inspection machine, so that the control unit can further determine whether the object to be inspected is good or bad according to the inspection result. However, after the probe card is used for a period of time, the probe is difficult to avoid the problem of deformation or damage, so the industry has been to directly replace the probe card.

Because of the machining and manufacturing factors, the dimensions of any two probe cards with the same specification are still slightly different from each other at microscopic angles, so the new probe card needs to manually correct the position of the probe and the product.

The calibration is performed manually, so the time consumption is very high, and the accuracy is poor. There is a room for discussion of a position calibration apparatus or method that can improve accuracy and reduce time cost.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a probe self-calibration method and system thereof, which obtains a vertical difference or a horizontal difference through an acquired image, and combines the vertical difference or the horizontal difference with a vertical position parameter or a horizontal position parameter to obtain a corrected vertical position parameter or horizontal position parameter, so as to correct a vertical measurement position or a horizontal measurement position of a probe card, and achieve the effects of reducing time cost and improving accuracy.

To achieve the above object, the present invention provides a probe self-calibration method, which comprises the steps of:

replacing a probe card, wherein the probe card is provided with at least one probe, and the probe is provided with a probe point;

acquiring a horizontal position image, wherein an image acquisition unit acquires the horizontal position image of the probe card, and the horizontal position image is provided with an image of at least one needle point;

calculating the horizontal difference, and calculating the horizontal difference of the needle point in the horizontal position image by a control unit, wherein the control unit is provided with position parameters of the probe card before the probe card is replaced, and the position parameters comprise a horizontal position parameter and a vertical position parameter; and

correcting the horizontal measurement position, combining the horizontal position parameter and the horizontal difference to obtain a corrected horizontal position parameter, and correcting the horizontal measurement position of the probe card by the control unit.

In one embodiment, the horizontal position parameter includes an X-axis position parameter, a Y-axis position parameter, or an angle position parameter; the horizontal difference amount includes an X-axis position difference amount, a Y-axis position difference amount, or an angular position difference amount.

In one embodiment, the method further includes a step of calculating a vertical difference, wherein the control unit controls the probe card to approach a load cell in a vertical direction, if a change in a value of the load cell is detected, the probe is determined to contact the load cell, and the control unit calculates the vertical difference of the probe according to the change. Or the control unit controls the probe card to approach a reference pad in the vertical direction, the image acquisition unit acquires an image of the needle point and transmits the image to the control unit, when the control unit detects that the needle point has relative displacement in the horizontal direction, the control unit judges that the needle point contacts the reference pad, and the control unit calculates the difference value of the vertical position relative to the vertical position parameter at the moment to form a vertical difference value.

The present invention further provides a probe self-calibration system applied to at least one probe card, the probe self-calibration system comprising:

a carrying platform;

a control unit;

the mobile unit is arranged on the carrying platform, is electrically connected with the control unit and is controlled by the control unit to carry the probe card; and

and the image acquisition unit is electrically connected with the control unit and acquires an image of the probe card.

In summary, the present invention provides a probe self-calibration system and method thereof, which utilizes an image capturing unit to capture an image of a tip of a probe card, a control unit obtains a horizontal difference and a vertical difference according to the image, and corrects a horizontal position parameter or a vertical position parameter according to the horizontal difference or the vertical difference. Thereby, the position correction can be performed without using the product as a reference sheet. Meanwhile, the position of the probe can be corrected without manual operation. Therefore, the invention can achieve the advantages of improving the precision and reducing the time cost.

Drawings

FIG. 1 is a schematic diagram of a probe self-calibration system according to the present invention.

FIG. 2 is a schematic view of a fiducial mark.

FIG. 3 is a flow chart of a probe self-calibration method according to the present invention.

Description of the reference numerals: 10-a stage; 100-load cell or reference pad; 11-a control unit; 12-a mobile unit; 13-an image acquisition unit; 130-fiducial markers; 14-a probe card; 140-a probe; 141-a needle tip; S1-S6-step.

Detailed Description

Referring to fig. 1, the present invention is a probe self-calibration system, which includes a carrier 10, a control unit 11, a moving unit 12 and at least one image capturing unit 13.

The carrier 10 has a load cell or reference pad 100. The carrier 10 can be used to carry a device under test, which can be a chip, a wafer or a panel.

The moving unit 12 is provided on the stage 10. The moving unit 12 is electrically connected to the control unit 11. The mobile unit 12 is provided with at least one probe card 14. The probe card 14 has at least one probe 140. Each probe 140 has at least one tip 141. The control unit 11 can control the movement of the moving unit 12 to transfer the probe card 14.

The image capturing unit 13 is electrically connected to the control unit 11 and is located above, at one side of, or below the moving unit 12, and the position is adjusted according to actual requirements. Referring to fig. 2, the image capturing unit 13 further includes a reference mark 130, and the reference mark 130 can be simultaneously included in the image during image capturing. The fiducial mark 130 may be a cross-hair or a fiducial mark.

The positional relationship (positional parameters) among the carrier 10, the moving unit 12, the probe card 14, the needle point 141 on the probe card 14, and the image capturing unit 13 is stored in the control unit 11 after the initial setting is completed, so that the moving unit 12 can move the probe card 14 in space relative to the carrier 10, that is, the probe card 14 can move or rotate relative to the carrier 10.

Referring to fig. 3, the present invention is a probe self-calibration method, comprising the steps of:

in step S1, a probe card is replaced. The probe card 14, which is located in the mobile unit 12 and has been used for a while, is removed and a new probe card 14 is replaced. The probe card 14 has at least one probe 140. Each probe 140 has at least one tip 141.

Since the components of the stage 10, the moving unit 12 and the image acquisition unit 13 are not changed, the mutual position relationship is still kept unchanged; however, since another probe card 14 is replaced, the positional relationship between the probe card 14 and the moving unit 12 after the replacement is changed, and therefore, correction is required.

If the mutual positional relationship among the components of the stage 10, the moving unit 12 and the image capturing unit 13 is further described above, the control unit 11 can be used to retrieve the mutual positional relationship among the stage 10, the moving unit 12 and the image capturing unit 13 again through an initialization operation if there is a change caused by human factors during the process of replacing the probe card 14.

In step S2, a horizontal position image is acquired. The image pickup unit 13 located above, on one side or below the moving unit 12 picks up a horizontal position image of the probe 140 of the probe card 14. The horizontal position image includes an image of at least one tip 141. The image pickup unit 13 transmits the horizontal position image to the control unit 11. Referring to fig. 2, the horizontal position image includes a reference mark 130, and the horizontal difference is the difference between the positions of the needle point 141 and the reference mark 130 in the horizontal position image. The fiducial mark 130 may be a cross-hair or a fiducial mark.

For example, the control unit 11 controls the moving unit 12 to transfer the replaced probe card 14 to a reference point of a known positional relationship according to the position parameter corresponding to the probe card 14 before replacement, at this time, the image acquired by the image acquiring unit 13 is as shown in fig. 2, the reference mark 130 is a position where the tip 141 of the probe 140 of the probe card 14 before replacement is expected to appear, however, the position of the tip 141 of the probe 140 of the probe card 14 after replacement has a significant difference from the reference mark 130.

In addition, the probe card 14 is not limited to be replaced and then controlled to move to the reference point, the reference point is a predetermined position where the positional relationship of each component is known, and the control unit 11 knows the mutual positional relationship of the stage 10, the moving unit 12 and the image acquisition unit 13 at the position of the reference point.

In the present invention, the probe card 14 can be replaced with another probe card 14 before replacement, while the control unit 11 knows the positional relationship among the stage 10, the moving unit 12, the image pickup unit 13, and the probe card 14; that is, the fiducial mark 130 shown in FIG. 2 is where the tip 141 of the probe 140 on the probe card 14 should appear before it is replaced.

In step S3, a level difference amount is calculated. The control unit 11 calculates the level difference of at least one tip 141 in the horizontal position image, the control unit 11 has a position parameter of the probe 140 on the probe card 14 before replacing the probe card 14, and the control unit 11 controls the moving unit 12 to transfer the probe card 14 to move relative to the stage 10 in the space according to the position parameter.

The position parameters include a horizontal position parameter and a vertical position parameter. The horizontal position parameter comprises an X axial position parameter, a Y axial position parameter or an angle position parameter; the horizontal difference amount includes an X-axis position difference amount, a Y-axis position difference amount, or an angular position difference amount.

In step S4, the horizontal measurement position is corrected. The control unit 11 combines the horizontal position parameter and the horizontal difference amount to obtain a corrected horizontal position parameter, and the control unit 11 controls the moving unit 12 by using the corrected horizontal position parameter so that the moving unit 12 corrects the horizontal measurement position of the probe card 14, that is, the control unit 11 combines the horizontal position parameter corresponding to the probe 141 before replacement with the horizontal difference amount calculated in step S3 to correct the horizontal position parameter to obtain the horizontal position parameter of the probe 141 after replacement.

To be more specific, the control unit 11 may transfer the probe card 14 to the transfer unit 12 to move using the corrected horizontal position parameter, and at this time, if the image acquisition unit 13 acquires an image, the corrected needle point 141 overlaps the reference mark 130.

Step S5, calculating a vertical difference, if the load Cell or the reference pad 100 is a load Cell, the control unit 11 controls the moving unit 12 to move vertically so that the probe card 14 approaches a load Cell (L oad Cell) in the vertical direction, if it is detected that the value of the load Cell changes, the control unit 11 determines that the probe 141 contacts the load Cell, and the control unit 11 calculates the vertical difference before and after replacing the probe 140 according to the moving distance of the moving unit 12 transferring the probe card 14 in the vertical direction and the vertical position parameter before replacing the probe card 14.

Alternatively, if the load cell or reference pad 100 is a reference pad. The control unit 11 controls the moving unit 12 to make the probe card 14 approach a reference pad in the vertical direction, the image capturing unit 13 captures an image of the needle point 141 and transmits the image to the control unit 11, when the control unit 11 detects that the needle point 141 is displaced in the horizontal direction according to the image, the control unit 11 determines that the needle point 141 has contacted the reference pad, and the control unit 11 calculates the vertical difference before and after replacing the probe card 140 according to the moving distance of the moving unit 12 in the vertical direction for transferring the probe card 14 and the vertical position parameter before replacing the probe card 14.

In another implementation, after step S5, the probes 141 on the replaced probe card 14 are overlapped with the reference marks 130 disposed on the image capturing unit 13, and when the probe card 14 is vertically transferred by the moving unit 12 such that the probes 140 touch the reference pads 100, the probes 140 are elastically deformed by the contact force such that the tips 141 are not overlapped with the reference marks 130, so that the control unit 11 can determine that the probes 140 touch the reference pads, and the control unit 11 calculates the vertical difference before and after the probes 140 are replaced according to the moving distance of the probe card 14 in the vertical direction transferred by the moving unit 12 and the vertical position parameter before the probe card 14 is replaced.

In step S6, the vertical measurement position is corrected. The control unit 11 combines the vertical position parameter and the vertical difference to form a corrected vertical position parameter, and the control unit 11 provides the vertical position parameter to the moving unit 12, so that the moving unit 12 corrects the vertical measurement position of the probe card 14, that is, the control unit 11 can move the probe card 14 by transferring through the moving unit 12 according to the corrected vertical position parameter, so that the control unit 11 can control the moving unit 12 to transfer the replaced probe card 14 relative to the stage 10.

In summary, the present invention provides a probe self-calibration system and method thereof, wherein an image of a tip 141 of a probe 140 of a probe card 14 is captured by an image capturing unit 13, a control unit 11 obtains a horizontal difference and a vertical difference of the tip 141 before and after replacement of the probe card 14 according to the image, and corrects a horizontal position parameter or a vertical position parameter according to the horizontal difference or the vertical difference. Thereby, the position correction can be performed without using the product as a reference sheet. Meanwhile, the position of the probe can be corrected without manual operation. Therefore, the invention can achieve the advantages of improving the precision and reducing the time cost.