Semiconductor chip LGSS cutting equipment and cutting method

Abstract

The invention discloses LGSS cutting equipment and a cutting method for a semiconductor chip, and the method comprises the steps: pasting a layer of elastic stretching film on the back surface of a wafer, then removing the metal at a cutting position through laser, carrying out the thermal guidance splitting cutting at the cutting position through laser energy, and finally rapidly separating the chip through a film expansion mode. By means of the cutting mode, heat can be dispersed in time, too large cutting channels caused by heat energy diffusion of laser are prevented, chippings generated after cutting are effectively prevented from being splashed to the surfaces of wafers, cracks, edge breakage and surface scratching of workpieces are prevented, the surfaces of the workpieces are smooth and clean, slag residues do not exist, the machining precision is high, the cutting faces are smooth, flat and burr-free, and cutting gaps are narrow. Therefore, the product yield and the processing efficiency are effectively improved, and the equipment and material cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor chip preparation, and in particular to a semiconductor chip LGSS cutting device and a cutting method. Background Art

[0002] When the semiconductor chip based on the whole wafer is prepared, it needs to be cut to obtain the chip of the required size. The commonly used cutting technology is laser cutting, that is, the back metal layer is removed in advance for the back cutting part, and then the laser beam is directly applied to the cutting part on the surface of the chip for cutting. Although this method can quickly achieve cutting, it has obvious disadvantages, that is, it will cause the melting and collapse of part of the metal on both sides of the cutting part and the silicon at the cutting part, resulting in uneven cutting part and large chip loss due to the wide cutting gap (usually greater than 25μm). Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a semiconductor chip LGSS cutting device, including a manipulator, and a feeding mechanism, a laminating mechanism, a cutting mechanism and a film expanding mechanism corresponding to the manipulator in sequence;

[0004] The robot is used to grab the wafers in the feeding mechanism and place them on the laminating mechanism for laminating, then grab the wafers after laminating and place them on the cutting mechanism for cutting, and then grab the cut wafers and place them in the film expanding mechanism for film expanding.

[0005] Wherein: the feeding mechanism comprises a wafer table and a wafer box placed on the wafer table, wherein the wafer box contains wafers.

[0006] Wherein: the coating mechanism includes a supporting platform 1, a vacuum suction cup arranged on the supporting platform 1, a steel ring arranged on the supporting platform 1 and located at the radial outer ring of the vacuum suction cup and the steel ring is arranged concentrically with the vacuum suction cup, and a roller assembly corresponding to the top of the vacuum suction cup.

[0007] Wherein: the cutting mechanism comprises a base, an X guide rail and a Y guide rail arranged on the base, and a positioning table 1 moving along the X guide rail and the Y guide rail;

[0008] The cutting mechanism also includes a gantry, and a laser cutter 1 and a laser cutter 2 arranged on the gantry, wherein the laser cutter 1 is used for laser metal removal of the cutting portion of the wafer on the positioning table 1, and the laser cutter 2 is used for laser cutting of the cutting portion of the wafer on the positioning table 1.

[0009] Wherein: the film expansion mechanism includes a machine platform and a film expansion component arranged on the machine platform;

[0010] The film expansion assembly includes a support platform 2 and a support platform 3 arranged on the support platform 2; a positioning platform 2 is arranged on the support platform 2, and an outer film expansion ring corresponding to the radial outer ring of the positioning platform 2; a cylinder 1 is arranged on the support platform 3, and an inner film expansion ring driven by the cylinder 1 and corresponding to the radial inner ring of the outer film expansion ring, and the positioning platform 2, the outer film expansion ring and the inner film expansion ring are concentrically arranged; a cylinder 2 and a pressure block driven by the cylinder 2 are also arranged on the support platform 3 for pressing and fixing the outer film expansion ring.

[0011] The present invention also provides a semiconductor chip LGSS cutting method, comprising the following steps:

[0012] S1. First, a layer of elastically stretchable film is attached to the back of the wafer;

[0013] S2, then, the metal laser is removed from the front cutting position of the wafer after the back film is attached to expose the silicon base;

[0014] S3, then, laser cutting is performed on the wafer at the corresponding cutting position, specifically, heat is generated by the laser and combined with the crystal orientation of the silicon wafer for thermal guidance to achieve wafer cutting;

[0015] S4, film expansion, that is, using stretching equipment to stretch the film to both sides, through the elastic stretching deformation of the film, drive the cracks after wafer cutting to move symmetrically to both sides, thereby achieving slitting.

[0016] Compared with the prior art, the present invention is a LGSS [Laser, Groving (removal of metal from the surface of the laser cutting position), Seamless (seamless laser cutting), Spread (film expansion)] cutting equipment and cutting method for semiconductor chips, which is achieved by attaching a layer of elastically stretchable film to the back of the wafer, then removing the metal at the cutting position by laser, and then thermally guiding the splitting and cutting by laser energy at the cutting position, and finally quickly separating the chip by film expansion. This cutting method can disperse heat in time, prevent the thermal energy diffusion of the laser from causing the cutting path to be too large, effectively prevent the debris after cutting from splashing onto the surface of the wafer, prevent the workpiece from cracking, collapsing and scratching the surface, the workpiece surface is smooth, no slag residue, high processing accuracy, smooth and flat cutting surface without burrs, and narrow cutting gap, thereby effectively improving the product yield and processing efficiency, saving equipment and material costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0018] Figure 2 It is a schematic diagram of the three-dimensional structure of the laminating mechanism of the present invention;

[0019] Figure 3 It is a schematic diagram of the three-dimensional structure of the cutting mechanism of the present invention;

[0020] Figure 4 It is a schematic diagram of the side structure of the cutting mechanism of the present invention;

[0021] Figure 5 It is a schematic diagram of the main structure of the film expansion mechanism of the present invention;

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the film expanding assembly of the film expanding mechanism of the present invention.

[0023] The numbers in the figure indicate: 10. wafer table; 11. wafer box; 12. wafer; 20. robot; 30. coating mechanism; 31. support platform 1; 32. vacuum suction cup; 33. steel ring; 34. roller assembly; 40. cutting mechanism; 41. base; 42. X guide rail; 43. Y guide rail; 44. positioning platform 1; 45. gantry; 46. laser cutter 1; 47. laser cutter 2; 50. film expansion mechanism; 51. machine table; 52. film expansion assembly; 521. support platform 2; 522. support platform 3; 523. cylinder 1; 524. inner film expansion ring; 525. cylinder 2; 526. pressure block; 527. outer film expansion ring. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0025] See also Figure 1-6 The present embodiment provides a semiconductor chip LGSS cutting device, including a robot 20, and a feeding mechanism, a coating mechanism 30, a cutting mechanism 40 and a film expanding mechanism 50 corresponding to the robot 20 in sequence; the robot 20 is used to grab the wafer in the feeding mechanism and place it on the coating mechanism 30 for filming, then grab the wafer after filming and place it on the cutting mechanism 40 for cutting, and then grab the wafer after cutting and place it in the film expanding mechanism 50 for film expanding.

[0026] The feeding mechanism includes a wafer table 10 and a wafer box 11 placed on the wafer table 10 , wherein the wafer box 11 contains wafers 12 .

[0027] Wherein: the coating mechanism 30 includes a supporting platform 31, a vacuum suction cup 32 arranged on the supporting platform 31, a steel ring 33 arranged on the supporting platform 31 and located at the radial outer ring of the vacuum suction cup 32 and the steel ring 33 is arranged concentrically with the vacuum suction cup 32, and a roller assembly 34 corresponding to the vacuum suction cup 32.

[0028] The cutting mechanism 40 includes a base 41, an X-guide rail 42 and a Y-guide rail 43 disposed on the base 41, and a positioning table 44 moving along the X-guide rail 42 and the Y-guide rail 43;

[0029] The cutting mechanism 40 also includes a gantry 45, and a laser cutter 46 and a laser cutter 47 arranged on the gantry 45. The laser cutter 46 is used for laser metal removal of the cutting portion of the wafer 12 on the positioning table 44, and the laser cutter 47 is used for laser hidden cutting of the cutting portion of the wafer 12 on the positioning table 44.

[0030] Wherein: the film expansion mechanism 50 includes a machine platform 51 and a film expansion assembly 52 disposed on the machine platform 51;

[0031] The film expansion assembly 52 includes a support platform 2 521 and a support platform 3 522 arranged on the support platform 2 521; a positioning platform 2 is arranged on the support platform 2 521, and an outer film expansion ring 527 corresponding to the radial outer ring of the positioning platform 2 is arranged; a cylinder 1 523 is arranged on the support platform 3 522, and an inner film expansion ring 524 driven by the cylinder 1 523 and corresponding to the radial inner ring of the outer film expansion ring 527 is arranged, and the positioning platform 2, the outer film expansion ring 527 and the inner film expansion ring 524 are arranged concentrically; a cylinder 2 525 and a pressure block 526 driven by the cylinder 2 525 are also arranged on the support platform 3 522 for pressing and fixing the outer film expansion ring 527.

[0032] The semiconductor chip LGSS cutting method based on the above-mentioned cutting equipment has the following working principle:

[0033] S1. First, a layer of elastically stretchable film is attached to the back of the wafer 12. Specifically, the wafer 12 in the wafer box 11 is grasped by the robot 20 and placed on the vacuum suction cup 32 of the film coating mechanism 20 for adsorption and positioning with the back facing upwards. Then, the film is covered on the surface of the wafer 12, and a circle of the film is pressed by the steel ring 33. Then, the film is tightly attached to the back of the wafer 12 by rolling with the roller assembly 34.

[0034] S2. Then, the metal laser at the cutting position of the front side of the wafer 12 after the back side film is pasted is removed to expose the silicon base. Specifically, the wafer 12 after the film is pasted is grabbed by the robot 20 and placed on the positioning table 44 of the cutting mechanism 40, and then the positioning table 44 is driven to move along the X guide rail 42 and the Y guide rail 43 and the laser cutter 46 is used to remove the laser metal at the cutting position of the wafer 12 on the positioning table 44 (the laser metal removal technology is to focus a short pulse laser on the wafer surface, and the pulse laser is continuously absorbed by the Low-K layer or the metal material. After absorbing a certain amount of energy, the Low-K layer or the metal material will be instantly vaporized or melted, thereby achieving the effect of material removal. This technology belongs to the prior art and will not be described in detail);

[0035] S3, then, the wafer 12 is seamlessly laser cut at the corresponding cutting position, specifically, the positioning table 1 44 is driven to move along the X rail 42 and the Y rail 43 and the laser cutter 2 47 is used to laser cut the cutting position of the wafer 12 on the positioning table 1 44 (the seamless laser cutting technology uses an infrared laser to create a pressure crack inside the wafer through the heat generated by the laser to achieve full wafer cutting. This technology belongs to the prior art and will not be described in detail);

[0036] S4, film expansion, specifically, the wafer 12 after laser cutting is grabbed by the robot 20 and placed on the positioning table 2 of the film expansion assembly 52, and then the outer film expansion ring 527 is used to press the outer edge of the film and the outer film expansion ring 527 is pressed and fixed by the pressure block 526 driven by the cylinder 2 525, and then the inner film expansion ring 524 is driven by the cylinder 1 523 to press the film corresponding to the radial inner ring of the outer film expansion ring 527, and finally, the lifting mechanism at the bottom of the positioning table 2 is used to drive the positioning table 2 to rise, so as to achieve the stretching of the film, and then the elastic stretching deformation of the film drives the wafer 12 to move symmetrically to both sides along the breaking point after laser cutting, so as to achieve the slitting of the wafer 12.

[0037] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A semiconductor chip LGSS cutting equipment, characterized in that: It comprises a robot (20), and a feeding mechanism, a film laminating mechanism (30), a cutting mechanism (40) and a film expanding mechanism (50) which correspond to the robot (20) in sequence; The robot (20) is used to grab the wafers in the feeding mechanism and place them on the laminating mechanism (30) for laminating, then grab the wafers after laminating and place them on the cutting mechanism (40) for cutting, and then grab the wafers after cutting and place them in the film expanding mechanism (50) for film expanding.

2. The semiconductor chip LGSS cutting equipment according to claim 1, characterized in that: The feeding mechanism comprises a wafer table (10) and a wafer box (11) placed on the wafer table (10), wherein the wafer box (11) contains wafers (12).

3. The semiconductor chip LGSS cutting equipment according to claim 2, characterized in that: The coating mechanism (30) includes a supporting platform (31), a vacuum suction cup (32) arranged on the supporting platform (31), a steel ring (33) arranged on the supporting platform (31) and located on the radial outer ring of the vacuum suction cup (32), and the steel ring (33) is arranged concentrically with the vacuum suction cup (32), and a roller assembly (34) corresponding to the top of the vacuum suction cup (32).

4. The semiconductor chip LGSS cutting equipment according to claim 3, characterized in that: The cutting mechanism (40) comprises a base (41), an X-guide rail (42) and a Y-guide rail (43) arranged on the base (41), and a positioning table (44) moving along the X-guide rail (42) and the Y-guide rail (43); The cutting mechanism (40) further comprises a gantry (45), and a laser cutter 1 (46) and a laser cutter 2 (47) arranged on the gantry (45), wherein the laser cutter 1 (46) is used for laser metal removal at a cutting position of a wafer (12) on the positioning platform 1 (44), and the laser cutter 2 (47) is used for laser thermal guidance cutting at a cutting position of a wafer (12) on the positioning platform 1 (44).

5. The semiconductor chip LGSS cutting equipment according to claim 4, characterized in that: The film expansion mechanism (50) comprises a machine platform (51) and a film expansion component (52) arranged on the machine platform (51); The film expansion assembly (52) includes a second support platform (521) and a third support platform (522) arranged on the second support platform (521); a second positioning platform is arranged on the second support platform (521), and an outer film expansion ring (527) corresponding to the radial outer ring of the second positioning platform; a cylinder (523) is arranged on the third support platform (522), and an inner film expansion ring (524) driven by the cylinder (523) and corresponding to the radial inner ring of the outer film expansion ring (527); the second positioning platform, the outer film expansion ring (527) and the inner film expansion ring (524) are arranged concentrically; the third support platform (522) is also provided with a second cylinder (525) and a pressure block (526) driven by the second cylinder (525) for pressing and fixing the outer film expansion ring (527).

6. A semiconductor chip LGSS cutting method, characterized in that: The steps include: S1. First, a layer of elastically stretchable film is attached to the back of the wafer; S2, then, the metal laser is removed from the front cutting position of the wafer after the back film is attached to expose the silicon base; S3, then, laser cutting is performed on the wafer at the corresponding cutting position, specifically, heat is generated by the laser and combined with the crystal orientation of the silicon wafer for thermal guidance to achieve wafer cutting; S4, film expansion, that is, using stretching equipment to stretch the film to both sides, through the elastic stretching deformation of the film, drive the cracks after wafer cutting to move symmetrically to both sides, thereby achieving slitting.

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