Silicon wafer chucking method

Abstract

The present application relates to a kind of silicon wafer chuck adsorption methods, before slicing, telescopic mechanism is positioned after driving chuck to extend set length to make chuck contact with silicon rod;Chucking generates negative pressure and absorbs the surface of crystal bar, keeps the position of chuck, and chuck keeps suction force;Telescopic mechanism locks travel;In telescopic mechanism is released after the surface of silicon rod and before locking travel, release the pressure on the surface of silicon rod.The telescopic end has locking device to prevent movement;Telescopic device controls chuck to release the pressure on the surface of silicon rod after contacting the surface of silicon rod, so that telescopic device can have the ability of adaptive adjustment before locking travel to avoid the axial pressure on silicon rod to be too large and break;Telescopic mechanism locking travel does not generate additional stress to silicon wafer, and cutting process and product quality are stable.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of wafer chuck adsorption method. BACKGROUND

[0002] The existing sheet silicon crystal is formed by cutting silicon rod, and the wafer chuck is used for adsorption to realize the transfer of silicon wafer in the process of cutting. The existing wafer chuck mechanism generally adopts three-axis sliding table or multi-degree-of-freedom mechanical arm to drive the wafer chuck with negative pressure suction function to adsorb the silicon wafer. Generally, in the process of cutting the silicon wafer, the linear cutting tool has a downward pressure on the silicon wafer. When the linear cutting tool is in the last stage, the pre-stress of the wafer chuck contact structure is controlled to contact the silicon wafer, which causes the silicon wafer to break in the cutting process, especially when the upper half of the silicon wafer is cut to more than half. SUMMARY

[0003] In order to solve the problem that the existing wafer chuck type silicon wafer is broken due to the stress of the wafer chuck driven by the pneumatic or hydraulic telescopic device during cutting.

[0004] The technical scheme of the present application is as follows: a wafer chuck adsorption method, using a wafer chuck assembly, the wafer chuck assembly includes a wafer chuck capable of generating negative pressure and a telescopic mechanism for driving the wafer chuck to extend and retract towards the silicon wafer.

[0005] The specific steps are as follows:

[0006] S1: Before slicing, the telescopic mechanism is positioned to drive the wafer chuck to extend a set length to contact the wafer chuck with the silicon rod;

[0007] S2: The wafer chuck generates negative pressure to suck the surface of the crystal rod, keeps the position of the wafer chuck, and the wafer chuck keeps the suction force;

[0008] S3: The telescopic mechanism is locked in stroke;

[0009] S4: After the cutting tool cuts the silicon rod, the silicon wafer is adsorbed on the wafer chuck.

[0010] After step S1 is completed, the telescopic mechanism releases the pressure on the surface of the silicon rod before step S3. Preferably, the wafer chuck assembly is arranged on a wafer chuck frame, and the wafer chuck assembly is arranged on a moving assembly to drive the wafer chuck assembly to approach or move away from the silicon rod. The wafer chuck assembly or the wafer chuck frame has a first sensor for sensing the extension length of the wafer chuck.

[0011] Preferably, the telescopic mechanism positioning includes the following steps:

[0012] (1) The telescopic mechanism drives the wafer chuck to extend, the telescopic mechanism releases the pressure on the wafer chuck, and the wafer chuck assembly is moved to contact the end of the silicon rod;

[0013] (2) When the suction cup encounters the silicon rod, the retractable end of the telescopic mechanism is pushed back by the silicon rod, and the first sensor gives a warning;

[0014] In step S1, the telescopic mechanism drives the suction cup to extend by a set length greater than the stroke distance of the suction cup assembly away from the end face of the silicon rod, and the suction cup contacts the surface of the silicon rod.

[0015] Preferably, the suction cup holder is vertically arranged, and the telescopic mechanism is fixed horizontally on the suction cup holder, and the retractable end of the telescopic mechanism is horizontally arranged and fixedly connected with the suction cup.

[0016] Preferably, in the re-taking step, the difference between the length of the second extension and the stroke distance of the suction cup assembly away from the end face of the silicon rod is less than the compression allowance of the suction cup.

[0017] Preferably, a second sensor for sensing the distance between the suction cup and the silicon rod is arranged on the suction cup holder or the suction cup assembly; the specific steps are as follows: when the second sensor senses that the distance between the suction cup and the silicon rod reaches a set distance, the moving assembly drives the suction cup assembly to move towards the end of the silicon rod at a reduced speed.

[0018] Preferably, a vacuum generator is arranged on the suction cup holder, and the suction cup is in communication with the vacuum port of the vacuum generator to realize the negative pressure generated by the suction cup.

[0019] Preferably, the first sensor is a contact sensor, and a slider capable of contacting the retractable end of the telescopic mechanism is fixed on the retractable end of the telescopic mechanism, the retractable end of the telescopic mechanism is pushed back by the silicon rod, the slider contacts the contact sensor, and the moving assembly stops moving.

[0020] The suction cup is located above the conveying platform, the moving assembly comprises a moving plate fixed on the suction cup holder, a moving motor is fixed on the lower part of the moving plate, a gear is fixed on the output end of the moving motor, and the conveying platform is fixed with a rack engaged with the gear.

[0021] Preferably, the telescopic mechanism is a locking cylinder, and in step (4), the locking mechanism of the locking cylinder works to limit the stroke of the locking cylinder, and the telescopic mechanism releases the pressure on the surface of the silicon rod to release the pressure in the locking cylinder.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) The retractable end has a locking device to prevent movement; the telescopic device controls the suction cup to release the pressure on the surface of the silicon rod after contacting the surface of the silicon rod, so that the telescopic device has the ability of self-adaptive adjustment before the locking stroke to avoid excessive axial pressure on the silicon rod and breakage; after the locking stroke of the telescopic mechanism, no additional stress is generated on the silicon wafer, and the cutting process and product quality are stable.

[0024] (2) The application utilizes the sensor and the control of the air pressure of the telescopic device to realize the more accurate process of the contact after the positioning of the suction cup and the silicon wafer, and the ranging error caused by the photoelectric sensor is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The structure schematic diagram of the suction cup assembly in the embodiment of the application;

[0026] Figure 2 For Figure 1 The partial enlarged schematic diagram;

[0027] Figure 3 The structure schematic diagram of the suction cup assembly;

[0028] Figure 4 The structure schematic diagram of the suction cup assembly;

[0029] In the figure: 10-suction cup holder, 20-suction cup, 30-second sensor, 40-first sensor,

[0030] 50-locking cylinder, 510-telescopic rod, 520-sliding block, 60-moving plate, 610-moving plate, 620-moving motor, 630-gear, 640-rack. DETAILED DESCRIPTION

[0031] The application will be described in detail below in combination with the drawings and specific embodiments.

[0032] Referring to Figures 1-3 A silicon wafer suction cup suction method utilizes a suction cup assembly, the suction cup assembly comprises a suction cup capable of generating negative pressure and a telescopic mechanism capable of driving the suction cup to stretch and retract towards a silicon wafer,

[0033] The specific steps are as follows:

[0034] S1: before slicing, the telescopic mechanism drives the suction cup to stretch out a set length to make the suction cup contact with a silicon rod after positioning;

[0035] S2: the suction cup generates negative pressure to suck the surface of the crystal rod, keeps the position of the suction cup, and the suction cup keeps the suction force;

[0036] S3: the telescopic mechanism is locked in stroke;

[0037] S4: after the cutting tool cuts the silicon rod, the sliced silicon wafer is suctioned on the suction cup.

[0038] After the completion of step S1, the telescopic mechanism releases the pressure on the surface of the silicon rod before step S3.

[0039] In step S, the telescopic mechanism releases the pressure on the suction cup, and the inner cavity of the cylinder is thus retracted due to the resistance of the crystal rod when the suction cup encounters the end face of the silicon rod in step (2).

[0040] In the embodiment, the telescopic end has a locking device for preventing the telescopic end from moving, which can lock the locking stroke of the telescopic mechanism; the telescopic device controls the cylinder to leak after the suction cup contacts the surface of the silicon rod, so that the cylinder can be self-adaptively adjusted before the locking stroke to avoid excessive axial pressure on the silicon rod from breaking; no additional stress is generated on the wafer after the locking stroke of the telescopic mechanism, and the cutting process and product quality are stable.

[0041] In the embodiment, the telescopic mechanism is fixed on a vertically arranged suction cup holder 10, and the telescopic end of the telescopic mechanism is transversely arranged and fixedly connected with the suction cup 20. The suction cup holder 10 is perpendicular to the telescopic direction of the telescopic mechanism, and during operation, the telescopic direction of the suction cup 20 is towards the end face of the silicon rod to be cut.

[0042] The suction cup holder 10 is provided with a vacuum generator, and the suction cup is in communication with the vacuum port of the vacuum generator to generate negative pressure.

[0043] In the embodiment, the telescopic mechanism is a locking cylinder 50, and in step S3, the locking cylinder 50 itself has a locking mechanism. When it is necessary to limit the stroke of the locking cylinder, the locking mechanism is used to lock the stroke, and the telescopic mechanism releases the pressure on the surface of the silicon rod by using the cylinder leak operation on the locking cylinder.

[0044] In the embodiment, the first sensor 40 is fixed on the suction cup holder 10, and the first sensor 40 is a contact sensor. The telescopic mechanism positioning includes the following steps:

[0045] (1) The telescopic mechanism drives the suction cup to extend, the telescopic mechanism releases the pressure on the suction cup, and the suction cup assembly is moved to make the suction cup close to and contact the end of the silicon rod;

[0046] (2) When the suction cup encounters the silicon rod, the telescopic end of the telescopic mechanism is pushed back by the silicon rod, and the first sensor 40 gives an early warning;

[0047] In step S1, the telescopic mechanism drives the suction cup to extend by a set length greater than the stroke distance of the suction cup assembly away from the end face of the silicon rod, and makes the suction cup contact the surface of the silicon rod.

[0048] In an embodiment of the present application, the telescopic rod 510 of the locking cylinder 50 is fixed with a slider 520 capable of contacting the telescopic rod 510. When the telescopic rod of the locking cylinder 50 is pushed back by the silicon rod, the slider 520 contacts the contact sensor 40, and the moving assembly stops moving.

[0049] After the suction cup assembly completes the suction of the wafer once, the suction cup assembly positioning and wafer taking steps are performed, and the specific steps are as follows:

[0050] (1) The moving mechanism retreats by a set length, the suction cup releases the negative pressure, the silicon wafer is transported away, the locking cylinder 50 drives the suction cup 20 to extend by a set length, the locking cylinder 50 releases the pressure on the suction cup 20, the moving mechanism moves the suction cup assembly to make the suction cup 20 close to and contact the end of the silicon rod;

[0051] (2) When the suction cup encounters the silicon rod, the extension end of the locking cylinder 50 is pushed back by the silicon rod; the first sensor is a contact sensor, which stops retracting until the contact sensor pre-alarm is contacted with the slider;

[0052] (3) The moving assembly drives the suction cup frame to move away from the end face of the silicon rod by a distance, then the locking cylinder 50 drives the suction cup to extend again, the second extension length of the locking cylinder 50 is greater than the travel distance of the suction cup assembly away from the end face of the silicon rod, and the suction cup contacts the surface of the silicon rod;

[0053] The suction cup generates negative pressure to suck the surface of the crystal bar, the locking cylinder 50 releases the pressure on the suction cup, the locking cylinder 50 locks the stroke, and the position of the suction cup is kept, and the suction cup keeps the suction force;

[0054] (4) After the cutting tool cuts the silicon rod, the cut silicon wafer is adsorbed on the suction cup;

[0055] (5) Repeat steps (1) to (5) to complete multiple cutting and wafer taking.

[0056] In an embodiment of the present application, a second sensor for sensing the distance between the suction cup and the silicon rod is arranged on the suction cup frame or the suction cup assembly; when the moving mechanism moves the suction cup to close to and contact the end of the silicon rod, the second sensor senses that the distance between the suction cup and the silicon rod reaches a set distance, and then the moving mechanism drives the suction cup assembly to move towards the end of the silicon rod at a reduced speed.

[0057] In the embodiment, the second sensor 30 is an optical sensor for distance measurement.

[0058] In an embodiment of the present application, the suction cup is located above the conveying platform, the moving mechanism includes a moving plate 610 fixed to the suction cup frame, a moving motor 620 fixed to the lower part of the moving plate 610, a gear 630 fixed to the output end of the moving motor, and a rack 640 fixed to the conveying platform and engaged with the gear 630.

[0059] When the moving motor 620 drives the gear 630 to rotate, the moving plate moves along the length direction of the rack, i.e. along the direction of the conveying platform, thereby achieving the overall movement of the suction cup assembly. The moving motor can be a servo variable frequency motor, which can control the moving speed according to the sensing condition of the optical sensor.

[0060] In order to ensure that the suction cup 20 uniformly adsorbs the silicon wafer and makes the adsorption process uniform in stress, a plurality of suction cups are arranged, the suction cups 20 are arranged in a cross shape, and each suction cup is driven by an independent locking cylinder 50.

[0061] The above merely illustrates the embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process conversion, or direct or indirect application in other related technical fields, which is made according to the content of the present application, shall be included in the patent protection scope of the present application.

Claims

1. A method for suctioning a silicon wafer by a silicon wafer chuck, characterized by, The invention discloses a suction disc assembly, which comprises a suction disc capable of generating negative pressure and a telescopic mechanism capable of driving the suction disc to stretch out and retract towards a silicon wafer. The specific steps are as follows: S1: Before slicing, the telescopic mechanism is positioned and then drives the suction disc to stretch out to a set length so that the suction disc contacts the silicon rod; S2: The suction disc generates negative pressure to suck the surface of the crystal rod, keeps the position of the suction disc, and the suction disc keeps the suction force; S3: The telescopic mechanism is locked in stroke; S4: After the cutting tool cuts the silicon rod, the sliced silicon wafer is adsorbed on the suction disc; After step S1 is completed, the telescopic mechanism releases the pressure on the surface of the silicon rod before step S3; The suction disc assembly is arranged on a suction disc holder, and the suction disc assembly is arranged on a moving assembly to drive the suction disc assembly to approach or move away from the silicon rod. The telescopic mechanism positioning comprises the following steps: (1) The telescopic mechanism drives the suction disc to stretch out, the telescopic mechanism releases the pressure on the suction disc, and the moving assembly moves the suction disc to approach and contact the end of the silicon rod; (2) When the suction disc meets the silicon rod, the telescopic end of the telescopic mechanism is pushed back by the silicon rod, and the first sensor gives a warning; In step S1, the telescopic mechanism drives the suction disc to stretch out to a set length which is greater than the stroke distance of the suction disc assembly moving away from the end surface of the silicon rod, and the suction disc contacts the surface of the silicon rod.

2. The method of claim 1, wherein the method further comprises: The suction disc holder is vertically arranged, the telescopic mechanism is fixed horizontally on the suction disc holder, and the telescopic end of the telescopic mechanism is horizontally arranged and fixedly connected with the suction disc.

3. The method of claim 1, wherein the method further comprises: After the suction disc assembly completes the step of sucking the silicon wafer once, the step of positioning the suction disc assembly and taking the wafer again is performed, The specific steps are as follows: (1) The moving mechanism retreats by a set length, the suction disc releases the negative pressure, the silicon wafer is transferred away, the locking cylinder drives the suction disc to stretch out by a set length, the locking cylinder releases the pressure on the suction disc, the moving assembly moves the suction disc to approach and contact the end of the silicon rod; (2) When the suction disc meets the silicon rod, the telescopic end of the telescopic mechanism is pushed back by the silicon rod; the first sensor is a contact sensor which contacts the slider to stop retracting until the contact sensor gives a warning; (3) The moving assembly drives the suction disc holder to move away from the end surface of the silicon rod by a distance, then the locking cylinder drives the suction disc to stretch out again, the length of the second stretching of the locking cylinder is greater than the stroke distance of the suction disc assembly moving away from the end surface of the silicon rod, and the suction disc contacts the surface of the silicon rod; The suction disc generates negative pressure to suck the surface of the crystal rod, the locking cylinder releases the pressure on the suction disc, the locking cylinder is locked in stroke, the position of the suction disc is kept, and the suction disc keeps the suction force; (4) After the cutting tool cuts the silicon rod, the sliced silicon wafer is adsorbed on the suction disc; The steps (1) to (5) are repeated to complete multiple slicing and wafer taking; In the step of taking the wafer again, the difference between the length of the second stretching and the stroke distance of the suction disc assembly moving away from the end surface of the silicon rod is less than the compression allowance of the suction disc.

4. The method of claim 1, wherein the method further comprises: The suction disc holder or the suction disc assembly is provided with a second sensor for sensing the distance between the suction disc and the silicon rod; the specific steps are as follows: after the second sensor senses that the distance between the suction disc and the silicon rod reaches a set distance, the moving assembly drives the suction disc assembly to move towards the end of the silicon rod at a reduced speed.

5. The method of claim 1, wherein the method further comprises: The suction disc holder is provided with a vacuum generator, and the suction disc is in communication with the vacuum port of the vacuum generator to generate negative pressure.

6. The method of claim 2, wherein the step of applying a vacuum to the silicon wafer chuck comprises the step of: The first sensor is a contact sensor, a slider capable of contacting the telescopic end of the telescopic mechanism is fixed on the telescopic end, the telescopic end is pressed back by the silicon rod, the slider contacts the contact sensor, and the moving assembly stops moving.

7. The method of claim 1, wherein the method further comprises: The moving assembly comprises a moving plate fixed on the suction plate frame, a moving motor is fixed on the lower part of the moving plate, a gear is fixed on the output end of the moving motor, and the conveying platform is provided with a rack engaged with the gear.

8. The method of claim 4 or 5, wherein the method further comprises: The telescopic mechanism is a locking cylinder, in step S3, the locking mechanism of the locking cylinder works to limit the stroke of the locking cylinder, and the telescopic mechanism releases the pressure on the surface of the silicon rod to leak in the locking cylinder.

Images