Fixture for solving single-sided grinding pits and its control method

Abstract

The present invention relates to a jig for resolving single-sided grinding pits and a control method thereof. The jig, which belongs to the field of silicon wafer processing technology, comprises a grinding jig. A vacuum pump connected to the grinding jig is provided at the lower end of the grinding jig. A vacuum adsorption tube is provided between the vacuum pump and the grinding jig. A vacuum connection connector is provided between the vacuum adsorption tube and the grinding jig. The grinding jig comprises a jig mounting flange, a vacuum chamber is provided within the jig mounting flange, a vacuum exhaust hole connected to the vacuum adsorption tube is provided on the vacuum chamber, a silicon wafer positioning groove is provided between the jig mounting flange and the vacuum chamber, and an inner rubber ring is provided on the silicon wafer positioning groove that is slot-type and nested with the silicon wafer positioning groove. The jig has the characteristics of a simple structure, convenient operation, and good stability. The jig solves the problem of pits and scratches in silicon wafer processing. The yield rate of the processing process is improved while reducing production costs.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer processing equipment, and in particular to a jig for solving the problem of single-sided grinding pits and a control method thereof. Background Art

[0002] Currently, after semiconductor silicon wafers are cut into slices through wire cutting, grinding equipment is needed to thin the surface and remove the damaged layer on the surface. The grinding process often involves two processes: rough grinding and fine grinding.

[0003] During the single-side grinding process of silicon wafers by the DISCO machine, the silicon wafers will produce edge chipping and fragmentation defects. Some silicon powder and particles generated by this defective mode will splash onto the positioning table inside the machine. When the silicon wafer is transferred to the positioning table during the processing, the positioning table vacuum absorbs the silicon wafer, causing the particles to be deeply pressed into the front and back of the silicon wafer. However, the existing DISCO machine has obvious defects and cannot effectively clean the surface of the positioning table. The silicon slag is small and cannot be identified by the naked eye. Pits or dimple defects can only be observed through a microscope or Kuroda 300TT.

[0004] When the positioning table generates vacuum adsorption, the silicon wafer contacts the positioning table, and silicon slag is easily embedded in the front and back sides of the silicon wafer, causing 6-30μm pit defects on the front and back sides of the silicon wafer, causing serious product quality problems and leading to product scrapping. Summary of the Invention

[0005] This invention primarily addresses the shortcomings of the prior art by providing a jig for single-sided grinding pits and a control method thereof. The jig features a simple structure, convenient operation, and excellent stability. It solves the problems of pitting and scratching in silicon wafer processing, improves the yield rate during processing, and reduces production costs.

[0006] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0007] A jig for resolving single-sided grinding pitting includes a grinding jig, a vacuum pump connected to the grinding jig disposed at the lower end of the grinding jig, a vacuum adsorption tube disposed between the vacuum pump and the grinding jig, and a vacuum connection connector disposed between the vacuum adsorption tube and the grinding jig. The grinding jig includes a jig mounting flange, a vacuum chamber disposed within the jig mounting flange, a vacuum exhaust hole disposed in communication with the vacuum adsorption tube, a silicon wafer positioning groove disposed between the jig mounting flange and the vacuum chamber, and an inner rubber ring disposed in the silicon wafer positioning groove and nested with the silicon wafer positioning groove. By enlarging the vacuum exhaust hole, the actual contact range between the positioning platform and the silicon wafer is reduced.

[0008] Preferably, an outer rubber ring is provided between the inner rubber ring and the fixture mounting flange, and is nested and connected to the silicon wafer positioning groove. By adding the inner and outer rubber rings to the silicon wafer positioning groove, the contact area of ​​the silicon wafer during vacuum suction of the grinding fixture is reduced.

[0009] Preferably, the inner ring side of the outer rubber ring and the inner ring side of the inner rubber ring are both provided with a plurality of rubber ring replacement grooves communicating with the inner rubber ring and the outer rubber ring.

[0010] Preferably, a plurality of discharge holes are provided between the inner rubber ring and the outer rubber ring, and a plurality of discharge and air inlet pipes connected to the discharge holes are provided at the lower end of the silicon wafer positioning groove.

[0011] Preferably, the vacuum adsorption tube is provided with a pressure reducing valve connected to the vacuum adsorption tube.

[0012] A control method for a jig for single-sided grinding pits includes the following steps:

[0013] Step 1: Use an air compressor to clean the upper end surface of the grinding jig.

[0014] Step 2: Place the inner rubber ring and outer rubber ring on the silicon wafer positioning groove.

[0015] Step 3: Place the silicon wafer to be ground into the silicon wafer positioning groove. At this time, no air is entering the discharge air inlet pipe.

[0016] Step 4: The vacuum pump is running, and the air in the vacuum chamber is extracted through the vacuum exhaust hole connected to the vacuum connection joint seat and the vacuum adsorption tube to form a vacuum negative pressure to adsorb the silicon wafer on the silicon wafer positioning groove.

[0017] Step 5: Grind the silicon wafer on one side. After the single-side grinding process is completed, the vacuum pump stops running, the negative pressure in the vacuum chamber is eliminated, and then air is taken in through the discharge air inlet pipe to push the silicon wafer out through the removal air hole.

[0018] Preferably, the pressure value of -89Kpa applied by the vacuum pump is reduced to a pressure value of -60Kpa through a pressure reducing valve.

[0019] The present invention can achieve the following effects:

[0020] The present invention provides a jig and control method for single-sided grinding pits. Compared with existing technologies, this jig features a simple structure, convenient operation, and excellent stability. It solves the problems of pitting and scratching in silicon wafer processing, improves the yield rate during processing, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a side structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the top structure of the present invention.

[0023] In the figure: grinding jig 1, vacuum connection joint seat 2, vacuum adsorption tube 3, pressure reducing valve 4, vacuum pump 5, discharge and air inlet pipe 6, jig mounting flange 7, stripping air hole 8, silicon wafer positioning groove 9, inner rubber ring 10, outer rubber ring 11, vacuum chamber 12, vacuum exhaust hole 13, rubber ring replacement groove 14. DETAILED DESCRIPTION

[0024] The technical solution of the invention is further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0025] Example: Figure 1 and Figure 2 As shown, a jig for resolving single-sided grinding pitting includes a grinding jig 1. A vacuum pump 5 is provided at the lower end of the grinding jig 1 and communicates with the grinding jig 1. A vacuum suction tube 3 is provided between the vacuum pump 5 and the grinding jig 1. The vacuum suction tube 3 is provided with a pressure reducing valve 4 that communicates with the vacuum suction tube 3. A vacuum connection connector 2 is provided between the vacuum suction tube 3 and the grinding jig 1. The grinding jig 1 includes a jig mounting flange 7, within which a vacuum chamber 12 is defined. The vacuum chamber 12 is provided with a vacuum exhaust hole 13 that communicates with the vacuum suction tube 3. A silicon wafer positioning groove 9 is provided between the jig mounting flange 7 and the vacuum chamber 12. The silicon wafer positioning groove 9 is provided with an inner rubber ring 10 that is interlockingly connected to the silicon wafer positioning groove 9. An outer rubber ring 11 is provided between the inner rubber ring 10 and the jig mounting flange 7 and is interlockingly connected to the silicon wafer positioning groove 9. Two rubber ring replacement grooves 14 are symmetrically distributed and connected to the inner rubber ring 10 and the outer rubber ring 11 on the inner ring side of the outer rubber ring 11. Four stripping holes 8 are provided between the inner rubber ring 10 and the outer rubber ring 11, and four discharge and air inlet pipes 6 connected to the stripping holes 8 are provided at the lower end of the silicon wafer positioning groove 9.

[0026] A control method for a jig for single-sided grinding pits includes the following steps:

[0027] Step 1: Use an air compressor to clean the upper end surface of the grinding fixture 1.

[0028] Step 2: Place the inner rubber ring 10 and the outer rubber ring 11 on the silicon wafer positioning groove 9.

[0029] Step 3: Place the silicon wafer to be ground into the silicon wafer positioning groove 9 , while the discharge air inlet pipe 6 does not take in air.

[0030] Step 4: The vacuum pump 5 is running, and the air in the vacuum chamber 12 is extracted through the vacuum exhaust hole 13 connected to the vacuum connection connector 2 and the vacuum adsorption tube 3, thereby forming a vacuum negative pressure to adsorb the silicon wafer onto the silicon wafer positioning groove 9. The pressure value of -89 kPa applied by the vacuum pump 5 is reduced to -60 kPa through the pressure reducing valve 4.

[0031] Step 5: Single-side grinding of the silicon wafer is performed. After the single-side grinding process is completed, the vacuum pump 5 stops running, the negative pressure in the vacuum chamber 12 is eliminated, and then air is taken in through the discharge air inlet pipe 6 to push the silicon wafer out through the stripping air hole 8.

[0032] The overall contact area between the silicon wafer positioning groove 9 and the silicon wafer is reduced, an inner rubber ring 10 and an outer rubber ring 11 are added to the silicon wafer positioning groove 9, and the range of the vacuum exhaust hole 13 in the vacuum chamber 12 is increased. By installing a pressure reducing valve 4 under the machine to reduce the adsorption pressure, the contact between the silicon wafer positioning groove 9 and the rubber ring is reduced, and the problem of pits caused by the contact between the silicon slag remaining on the surface of the grinding jig 1 and the silicon wafer is solved.

[0033] In summary, this single-sided grinding fixture and its control method offer simple structure, convenient operation, and excellent stability. They address the issues of pitting and scratching in silicon wafer processing, improving processing yield while reducing production costs.

[0034] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the scope of the present invention are included in the patent scope of the present invention.

Claims

1. A control method for a jig for single-sided grinding pits, characterized by: The jig for solving the problem of single-sided grinding pits includes a grinding jig (1), a vacuum pump (5) connected to the grinding jig (1) is provided at the lower end of the grinding jig (1), a vacuum adsorption tube (3) is provided between the vacuum pump (5) and the grinding jig (1), a pressure reducing valve (4) connected to the vacuum adsorption tube (3) is provided on the vacuum adsorption tube (3), and a vacuum connection joint seat (2) is provided between the vacuum adsorption tube (3) and the grinding jig (1); the grinding jig (1) includes a jig mounting flange (7), a vacuum cavity (12) is provided in the jig mounting flange (7), a vacuum exhaust hole (13) connected to the vacuum adsorption tube (3) is provided on the vacuum cavity (12), a silicon wafer positioning groove (9) is provided between the jig mounting flange (7) and the vacuum cavity (12), and an inner rubber ring (10) is provided on the silicon wafer positioning groove (9) and is connected to the silicon wafer positioning groove (9) in a slot-like manner; An outer rubber ring (11) is provided between the inner rubber ring (10) and the fixture mounting flange (7) and is connected to the silicon wafer positioning groove (9) in a slot-type nested manner. A plurality of stripping air holes (8) are provided between the inner rubber ring (10) and the outer rubber ring (11). A plurality of discharge air inlet pipes (6) connected to the stripping air holes (8) are provided at the lower end of the silicon wafer positioning groove (9). The control method includes the following steps: Step 1: Use an air gun to blow clean the upper end surface of the grinding jig (1); Step 2: Place the inner rubber ring (10) and the outer rubber ring (11) on the silicon wafer positioning groove (9); Step 3: Place the silicon wafer to be ground into the silicon wafer positioning groove (9), and at this time, the discharge air inlet pipe (6) does not take in air; Step 4: The vacuum pump (5) is operated to extract the air in the vacuum chamber (12) through the vacuum exhaust hole (13) connected to the vacuum connection joint seat (2) and the vacuum adsorption tube (3), thereby forming a vacuum negative pressure to adsorb the silicon wafer onto the silicon wafer positioning groove (9); the pressure value of -89Kpa applied by the vacuum pump (5) is reduced to a pressure value of -60Kpa through the pressure reducing valve (4); Step 5: Single-sided grinding of the silicon wafer is performed. After the single-sided grinding process is completed, the vacuum pump (5) stops running, the negative pressure in the vacuum chamber (12) is eliminated, and then air is introduced into the discharge air inlet pipe (6) to push the silicon wafer out through the discharge air hole (8).

2. The control method for a jig for solving single-sided grinding pits according to claim 1, characterized in that: The inner ring side of the outer rubber ring (11) and the inner ring side of the inner rubber ring (10) are both provided with a plurality of rubber ring replacement grooves (14) that are connected to the inner rubber ring (10) and the outer rubber ring (11).

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