Wafer clamp and indium column stripping method

Abstract

The invention discloses a wafer clamp and an indium column stripping method, and aims to fix a wafer, facilitate the taking of the wafer, easily strip an indium metal layer in cooperation with a washing technique, and prevent the indium metal layer from damaging an indium column. The wafer clamp comprises a disc body, a lifting rod and a pressing block, the lifting rod is connected with the disc body, at least two limiting columns are arranged on the side, opposite to the lifting rod, of the disc body, grooves are formed in the outer walls of the limiting columns, and the bottoms of the grooves are used for making contact with the peripheral wall of a wafer; the pressing block is fixed on the disc body in a detachable manner so as to press the wafer in the groove, and belongs to the technical field of chip processing.

Description

Technical Field

[0001] The present invention belongs to the technical field of chip processing, and more specifically, relates to a round wafer clamp and an indium column stripping method. Background Art

[0002] The infrared focal plane hybrid chip is the core component of the infrared focal plane detector assembly. The hybrid chip is prepared by interconnecting the infrared focal plane array chip and the silicon readout circuit chip through indium pillar flip-chip. A very important process that affects the pass rate of the infrared focal plane hybrid chip is the wafer indium pillar peeling.

[0003] At present, most indium column stripping uses a wet stripping method, which is to place the wafer on a hanging basket, soak it and then rinse it directly. The indium metal layer can easily scratch the indium column, and the wafer is not fixed and can easily fall off during rinsing. Summary of the invention

[0004] The main purpose of the present invention is to provide a wafer clamp, which is designed to fix the wafer and facilitate the removal of the wafer. The indium metal layer can be easily peeled off with a flushing technique to prevent the indium metal layer from damaging the indium column; at the same time, an indium column peeling method is provided.

[0005] According to a first aspect of the present invention, there is provided a wafer clamp, comprising a plate body, a lifting rod and a pressure block, wherein the lifting rod is connected to the plate body, and at least two limiting columns are provided on a side of the plate body facing away from the lifting rod, and the outer wall of the limiting column is provided with a groove, and the bottom of the groove is used to contact the outer peripheral wall of the wafer;

[0006] The pressing block is fixed on the disk body in a detachable manner to press the wafer tightly into the groove.

[0007] In the above-mentioned wafer clamp, the disk body is in the shape of a disk, and there are three limiting pillars which are circumferentially arranged around the axis of the disk body.

[0008] In the above-mentioned wafer clamp, the groove is an annular groove.

[0009] In the above-mentioned wafer clamp, a guide groove is provided on the side of the disk body facing away from the lifting rod, and the guide groove extends radially along the disk body. The pressure block is slidably matched with the guide groove and can adjust its position along the extension direction of the guide groove.

[0010] In the above-mentioned wafer clamp, the pressing block is provided with a long waist hole, and the extending direction of the long waist hole is parallel to the extending direction of the guide groove;

[0011] It also includes a screw, a threaded hole is provided at the bottom of the guide groove, and the screw passes through the long waist hole and is threadedly connected with the threaded hole.

[0012] In the above-mentioned wafer clamp, the pressing block comprises a body, and the body is provided with a guide portion adapted to the guide groove;

[0013] A clamping portion is provided at one end of the main body close to the axis of the disk body, and a limiting tooth is provided at one end of the clamping portion facing away from the disk body. The limiting tooth protrudes in a direction close to the axis of the disk body, and a gap is provided between the limiting tooth and the disk body.

[0014] In the above-mentioned wafer clamp, a surface of the limiting tooth facing the disk body is an inclined surface, and the inclined surface is inclined toward the disk body in a direction away from the axis of the disk body.

[0015] In the above-mentioned wafer clamp, a plurality of first support columns are provided on a side of the plate body facing away from the lifting rod, and the plurality of first support columns are circumferentially arranged around the axis of the plate body;

[0016] The distance between the side of the groove away from the disk body and the disk body is a first distance, the distance between the side of the groove close to the disk body and the disk body is a second distance, and the height of the first support column is less than the first distance and greater than the second distance.

[0017] In the above-mentioned wafer clamp, a plurality of second support columns are provided on the side of the disk body facing away from the lifting rod, and the plurality of second support columns are circumferentially arranged around the axis of the disk body, and the height of the second support columns is greater than the height of the limiting columns.

[0018] According to a second aspect of the present invention, there is provided an indium pillar stripping method, which relates to the wafer clamp as described in the first aspect, and comprises the following steps:

[0019] Step 1: Use a wafer fixture to clamp the wafer, immerse the wafer in the degumming solution, and heat it for a predetermined time;

[0020] Step 2: Take out the wafer from the degumming liquid, use a syringe to spray the degumming liquid on the edge of the wafer, rinse it until the indium metal layer swells, and use tweezers to peel off the indium metal layer.

[0021] In the above-mentioned indium column stripping method, in step 1, heating is performed in a water bath at a temperature of 75° C. to 85° C.

[0022] In the above-mentioned indium column stripping method, in step 1, the heating time is 0.8 to 1.2 hours.

[0023] In the above-mentioned indium column stripping method, in step 2, after removing the indium metal layer, acetone is used to rinse off the degumming liquid on the wafer; then, alcohol is used to rinse the readout circuit on the wafer, and then drying is performed.

[0024] One of the above technical solutions of the present invention has at least one of the following advantages or beneficial effects:

[0025] In the present invention, a limiting column is arranged on the disk body to locate the position of the round wafer. The outer wall of the limiting column is provided with a groove. When the pressure block presses the round wafer into the groove, the round wafer can be fixed. At the same time, a gap is left between the round wafer and the disk body to ensure that the round wafer is in a suspended state. The round wafer can be easily taken by relying on the lifting rod. When the indium column is peeled off, it is more convenient for the operator to spray the degumming liquid due to the clamping of the clamp. The expansion of the indium metal layer can be observed more intuitively, and the indium metal layer can be easily peeled off to avoid the indium metal layer damaging the indium column during flushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0027] Figure 1 is a front view of the wafer clamp of the present invention;

[0028] Figure 2 is a three-dimensional diagram of a wafer clamp of the present invention;

[0029] Figure 3 The wafer clamp of the present invention Figure 2 A partial enlarged view of A;

[0030] Figure 4 It is a schematic structural diagram of a pressing block of a wafer clamp of the present invention.

[0031] Among them, the reference numerals of the figures are:

[0032] 1. disk body; 11. guide groove; 2. lifting rod; 3. pressure block; 31. long waist hole; 32. main body; 33. guide part; 34. clamping part; 35. limiting tooth; 351. inclined surface; 4. limiting column; 41. groove; 5. screw; 6. first support column; 7. second support column; a. first spacing; b. second spacing. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] Reference Figures 1 to 4As shown, according to the first aspect of the present invention, a wafer clamp is provided, comprising a plate body 1, a lifting rod 2 and a pressing block 3, wherein the lifting rod 2 is connected to the plate body 1, and at least two limiting columns 4 are provided on the side of the plate body 1 facing away from the lifting rod 2, and the outer wall of the limiting column 4 is provided with a groove 41, and the bottom of the groove 41 is used to contact the outer peripheral wall of the wafer, and the pressing block 3 is fixed to the plate body 1 in a detachable manner. When in use, the wafer is inserted into the groove 41, and the pressing block 3 is used to press the wafer to the bottom of the groove 41, so that the wafer can be fixed;

[0035] At the same time, a gap is left between the round wafer and the disk body 1 to ensure that the round wafer is in a suspended state; the round wafer can be easily picked up by relying on the lifting rod 2, and when the indium column is peeled off, it is more convenient for the operator to spray the degumming liquid due to the clamping of the clamp, and the expansion of the indium metal layer can be observed more intuitively, and then the indium metal layer can be easily peeled off to avoid the indium metal layer damaging the indium column during washing.

[0036] In this embodiment, the disk body 1 is disk-shaped, and there are three limiting columns 4 which are circumferentially arranged around the axis of the disk body 1. Specifically, the three limiting columns 4 and the pressing block 3 are evenly distributed at four positions of the axis of the disk body 1. The three limiting columns 4 can well locate the position of the wafer, and the pressing block 3 presses the wafer against the middle limiting column 4.

[0037] In this embodiment, the groove 41 is an annular groove, which is easy to process and convenient to install.

[0038] Preferably, the side of the annular groove close to the disk body 1 is connected to the disk body 1 by an annular slope, and the outer diameter of the annular slope gradually increases in the direction close to the disk body 1, so that the annular slope has a guiding function. After the wafer touches the annular slope, it can slide along the annular slope into the annular groove.

[0039] In this embodiment, a guide groove 11 is provided on the side of the disc body 1 facing away from the lifting rod 2. The guide groove 11 extends along the radial direction of the disc body 1. The pressing block 3 is slidably matched with the guide groove 11. The pressing block 3 is provided with a long waist hole 31. The extension direction of the long waist hole 31 is parallel to the extension direction of the guide groove 11.

[0040] It also includes a screw 5. The bottom of the guide groove 11 is provided with a threaded hole. The screw 5 passes through the long waist hole 31 and is threadedly connected with the threaded hole.

[0041] During actual use, the screw 5 is not tightened first. After the round wafer is put in, the outer wall of the round wafer is allowed to touch the bottom of the groove 41, and the pressing block 3 can be pushed to slide along the guide groove 11. After the pressing block 3 presses the round wafer, the screw 5 is tightened to complete the fixation of the pressing block 3.

[0042] Specifically, the pressing block 3 includes a body 32, and a guide portion 33 adapted to the guide groove 11 is provided on the body 32. The guide portion 33 is located in the guide groove 11 to ensure that the pressing block 3 is adjusted along the guide groove 11.

[0043] A clamping portion 34 is provided at one end of the main body 32 close to the axis of the disk body 1, and the clamping portion 34 contacts the outer peripheral wall of the round crystal, thereby clamping the round crystal; a limiting tooth 35 is provided at the end of the clamping portion 34 facing away from the disk body 1, and the limiting tooth 35 protrudes along the direction close to the axis of the disk body 1. A gap is provided between the limiting tooth 35 and the disk body 1, and the gap can accommodate the round crystal. The round crystal can be restricted between the disk body 1 and the limiting tooth 35 by the limiting tooth 35 and is not easy to loosen.

[0044] Preferably, the side of the limiting tooth 35 facing the disc body 1 is a slope 351, which is inclined toward the disc body 1 in a direction away from the axis of the disc body 1. The slope 351 mainly serves as a guide to ensure that the pressing part 34 can press against the outer peripheral wall of the round wafer.

[0045] In this embodiment, a plurality of first support columns 6 are provided on the side of the tray body 1 facing away from the lifting rod 2, and the plurality of first support columns 6 are circumferentially arranged around the axis of the tray body 1;

[0046] The spacing between the side of the groove 41 away from the disc body 1 and the disc body 1 is a first spacing a, and the spacing between the side of the groove 41 close to the disc body 1 and the disc body 1 is a second spacing b. The height of the first support column 6 is less than the first spacing a and greater than the second spacing b. The thickness of the wafer is less than the width of the groove 41, that is, the thickness of the wafer is less than the difference between the first spacing a and the second spacing b.

[0047] The first support column 6 is mainly used to support the side of the wafer close to the disk body 1 to ensure that there is a gap between the wafer and the disk body 1. During immersion, the degumming liquid can fully contact the wafer, and the first support column 6 can ensure that the wafer will not move up and down after being pressed. Therefore, the height of the first support column 6 needs to be limited to ensure that the first support column 6 can push the wafer that has been stuck in the groove 41.

[0048] In this embodiment, a plurality of second support columns 7 are provided on the side of the disk body 1 facing away from the lifting rod 2. The plurality of second support columns 7 are circumferentially arranged around the axis of the disk body 1. The height of the second support columns 7 is greater than the height of the limiting columns 4. The second support columns 7 are mainly used to ensure that after the disk body 1 is immersed in the degumming liquid, the wafer can be suspended in the air so that the degumming liquid can fully contact the wafer. Therefore, the second support columns 7 can support the disk body 1 in the container containing the degumming liquid.

[0049] According to a second aspect of the present invention, there is provided an indium pillar stripping method, which relates to the above-mentioned wafer clamp and comprises the following steps:

[0050] Step 1: Use the wafer clamp to clamp the wafer. Relying on the pressing block 3 and the limiting column 4, the pressing block 3 presses the wafer onto the limiting column 4. Then the plate 1 can be moved by the lifting rod 2 to move the wafer. Then, the wafer is immersed in a beaker containing the debonding solution. Then, the beaker is placed in a water bath and heated at 80°C for 1 hour.

[0051] Step 2: Take out the wafer from the beaker, lift the wafer by the lifting rod 2, use a syringe to spray the degumming liquid on the edge of the wafer to rinse, until the indium metal layer swells, and use tweezers to peel off the indium metal layer; in this way, the indium metal layer is prevented from scratching the indium column, and then continue to use the syringe to spray the degumming liquid to rinse off the remaining indium metal layer until there is no indium metal layer left on the surface of the wafer;

[0052] Next, use acetone to rinse off the degumming liquid on the wafer; then use alcohol to rinse the readout circuit on the wafer for 5 minutes. Use an alcohol spray gun when spraying alcohol. Set the pressure of the alcohol spray gun to 0.1-0.2Mpa, and then dry it.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wafer clamp, It is characterized in that It includes a disc body, a lifting rod and a pressure block, wherein the lifting rod is connected to the disc body, and at least two limiting columns are arranged on the side of the disc body facing away from the lifting rod, and the outer wall of the limiting column is provided with a groove, and the bottom of the groove is used to contact the outer peripheral wall of the round wafer; The pressing block is fixed on the disk body in a detachable manner to press the wafer tightly into the groove.

2. The wafer holder according to claim 1, It is characterized in that The disc body is disc-shaped, and the number of the limiting columns is three and they are circumferentially arranged around the axis of the disc body.

3. The wafer clamp according to claim 1, It is characterized in that The groove is an annular groove.

4. The wafer clamp according to claim 2, It is characterized in that A guide groove is provided on one side of the disc body facing away from the lifting rod. The guide groove extends in the radial direction of the disc body. The pressing block is slidably matched with the guide groove and can adjust its position along the extending direction of the guide groove.

5. The wafer holder according to claim 4, It is characterized in that The pressing block is provided with a long waist hole, and the extension direction of the long waist hole is parallel to the extension direction of the guide groove; It also includes a screw, a threaded hole is provided at the bottom of the guide groove, and the screw passes through the long waist hole and is threadedly connected with the threaded hole.

6. The wafer holder according to claim 4, It is characterized in that The pressing block comprises a body, and the body is provided with a guide portion adapted to the guide groove; A clamping portion is provided at one end of the main body close to the axis of the disk body, and a limiting tooth is provided at one end of the clamping portion facing away from the disk body. The limiting tooth protrudes in a direction close to the axis of the disk body, and a gap is provided between the limiting tooth and the disk body.

7. The wafer holder according to claim 6, It is characterized in that A side of the limiting tooth facing the disc body is an inclined surface, and the inclined surface is inclined toward the disc body in a direction away from the axis of the disc body.

8. The wafer holder according to claim 2, It is characterized in that A plurality of first support columns are provided on a side of the disk body facing away from the lifting rod, and the plurality of first support columns are circumferentially arranged around the axis of the disk body; The distance between the side of the groove away from the disk body and the disk body is a first distance, the distance between the side of the groove close to the disk body and the disk body is a second distance, and the height of the first support column is less than the first distance and greater than the second distance.

9. The wafer holder according to claim 2, It is characterized in that A plurality of second support columns are provided on a side of the disk body facing away from the lifting rod. The plurality of second support columns are circumferentially arranged around the axis of the disk body. The height of the second support columns is greater than the height of the limiting columns.

10. A method for stripping an indium column, It is characterized in that The wafer clamp according to any one of claims 1 to 9 comprises the following steps: Step 1: Use a wafer fixture to clamp the wafer, immerse the wafer in the degumming solution, and heat it for a predetermined time; Step 2: Take out the wafer from the degumming liquid, use a syringe to spray the degumming liquid on the edge of the wafer, rinse it until the indium metal layer swells, and use tweezers to peel off the indium metal layer.

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