Carrying disc for negative pressure adsorption, carrying device for negative pressure adsorption and stripping platform

Abstract

The invention relates to a carrying disc for negative pressure adsorption, which is a plate body and comprises a carrying surface and a bottom surface. A gas channel is formed in the carrying disc and communicated with the bearing face and the bottom face, and the gas channel forms a plurality of ventilation openings in the bearing face. The total opening area of the plurality of ventilation openings on the bearing surface is smaller than 50% of the area of the carrying disc and larger than 0.2% of the area of the carrying disc. The heat conductivity coefficient of the carrying disc is greater than 100W / mK; wherein W is watt (watt), m is meter length, and K is absolute temperature scale.

Description

Technical Field

[0001] The invention relates to a wafer thinning process, and in particular to a carrier plate, a carrying device and a stripping platform for negative pressure adsorption of a carrier substrate in a wafer stripping operation. Background Art

[0002] The current wafer process is developing towards thinning, but in the current wafer thinning process, the gradually thinned wafer has insufficient stress strength and is prone to breakage. Therefore, before the thinning process, the wafer will be bonded to a carrier substrate to improve the mechanical strength, and then the wafer will be subjected to thinning processes such as chemical mechanical polishing.

[0003] After the thinning process, the wafer and the carrier substrate need to be heated to weaken the bonding strength, and then the carrier substrate is peeled off by a vacuum carrier substrate peeling device, and then the carrier substrate is placed on a cooling platform for cooling and recycling.

[0004] In the above process, the wafer also needs to be fixed on the carrier. For wafer fixation, force must be applied evenly to the outer side of the wafer so that the wafer is evenly stressed during the process of peeling off the carrier substrate to avoid warping or breaking of the wafer. Summary of the invention

[0005] Based on the above technical issues, the present invention provides a carrier plate for negative pressure adsorption, a negative pressure adsorption carrying device and a peeling platform, which can apply a uniformly distributed negative pressure adsorption force to the sheet product.

[0006] The present invention proposes a carrier for negative pressure adsorption, the carrier is a plate body, including a bearing surface and a bottom surface. A gas channel is formed inside the carrier, connecting the bearing surface and the bottom surface, and the gas channel forms a plurality of ventilation openings on the bearing surface. The total opening area of ​​the plurality of ventilation openings on the bearing surface is less than 50% of the area of ​​the carrier and greater than 0.2% of the area of ​​the carrier. The thermal conductivity of the carrier is greater than 100W / mK; wherein W is watt, m is meter, and K is the absolute temperature scale.

[0007] Preferably, the material of the carrier is a porous medium, and the gaps in the porous medium are at least partially connected to form a gas channel.

[0008] Preferably, the porous medium is a sintered material.

[0009] Preferably, the material of the carrier is airtight, and the carrier further comprises a plurality of through holes, the plurality of through holes connect the carrier surface and the bottom surface to serve as gas passages, and the plurality of through holes form the plurality of ventilation openings on the carrier surface.

[0010] Preferably, the carrier further comprises a plurality of grooves, the plurality of grooves extending on the carrying surface and at least extending to one through-hole, the plurality of through-holes and the plurality of grooves together forming the plurality of ventilation openings on the carrying surface.

[0011] The present invention also provides a bearing device for negative pressure adsorption, comprising a bearing platform and the aforementioned carrier plate. The top surface of the bearing platform has a mounting groove. The carrier plate is escalably disposed in the mounting groove of the bearing platform.

[0012] Furthermore, the supporting device for negative pressure adsorption also includes an adsorption component, which is arranged in the installation groove, and the adsorption component is used to be connected to the vacuum adsorption hole of the exhaust device and the air guide groove connected to the vacuum adsorption hole.

[0013] The present invention also proposes a peeling platform for peeling a wafer from a carrier substrate, comprising a base, a carrying device, a cooling plate and a carrier substrate peeling device. Two movable guides are arranged on two opposite sides of the base. The carrying device is arranged on the base and is located between the two movable guides. The carrying device has a carrying platform and a carrier plate as described above. The top surface of the carrying platform has a mounting groove. The carrier plate is movably arranged in the mounting groove of the carrying platform, and the carrying surface is used to carry the wafer combined with the carrier substrate. The cooling plate is arranged on the base and is located between the two movable guides. The carrier substrate peeling device comprises a movable seat and a vacuum suction cup. The movable seat is movably combined with the two movable guides; the vacuum suction cup is movably arranged on the movable seat, and is used to adsorb on the carrier substrate to peel the carrier substrate from the wafer, and move the carrier substrate to the cooling plate of the plate cooling device.

[0014] Preferably, each movable guide member is provided with a guide groove, and the movable seat includes two pillars and a bracket connecting the two pillars, the two pillars are respectively inserted into each guide groove so that the movable seat can be movably combined with the movable guide member, and the vacuum suction cup is movably arranged on the bracket.

[0015] Preferably, the peeling platform also includes a first linear drive and a second linear drive; the first linear drive is arranged on the base and connected to one of the two pillars, and is used to drive each of the two pillars to move along each guide groove; the vacuum suction cup is connected to the bracket through the second linear drive, and is used to drive the vacuum suction cup to move toward the base or away from the base.

[0016] Preferably, through the plate cooling device and the peeling platform with the plate cooling device proposed in the present invention, the positive adhesive force generated by the glue on the bottom surface of the carrier substrate will not occur, thereby avoiding the problem of failure to pick up the carrier substrate during the subsequent transfer of the carrier substrate, reducing the error rate of the peeling operation, and effectively improving the yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a cross-sectional schematic diagram and a top view of a carrier plate used for negative pressure adsorption in Application Example 1 of an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the enlarged cross section of a local area.

[0019] Figure 3 It is a cross-sectional schematic diagram and a top view of a carrier plate used for negative pressure adsorption in Application Example 2 of an embodiment of the present invention.

[0020] Figure 4 yes Figure 3 Schematic diagram of the enlarged cross section of a local area.

[0021] Figure 5 It is a cross-sectional schematic diagram and a top view of a carrier plate used for negative pressure adsorption in Application Example 3 of an embodiment of the present invention.

[0022] Figure 6 yes Figure 5 Schematic diagram of the enlarged cross section of a local area.

[0023] Figure 7 It is a three-dimensional diagram of a peeling platform in an embodiment of the present invention, revealing a state where the carrier plate is separated.

[0024] Figure 8 It is a three-dimensional diagram of a peeling platform in an embodiment of the present invention.

[0025] Fig. 9 and Fig.10 It is a cross-sectional schematic diagram of a carrier plate, a wafer to be peeled off, and its carrier substrate in an embodiment of the present invention.

[0026] Figures 11 to 15 It is a three-dimensional diagram of a peeling platform in an embodiment of the present invention, used to reveal the process of peeling off the carrier substrate.

[0027] Explanation of the reference numerals: 1-peeling platform; 110-carrying plate; 110a-carrying surface; 110b-bottom surface; 110c-gas channel; 110d-ventilation opening; 114-groove; 120-heating device; 210-base; 212-side; 220-carrying device; 222-carrying platform; 222a-installation groove; 223-adsorption component; 223a-vacuum adsorption hole; 223b-air guide groove; 222a; installation groove; 224-top rod; 225-heater; 230-cooling plate; 240-carrier substrate peeling device; 242-moving seat; 244-vacuum suction cup; 260-first linear drive; 250-moving guide; 252-guide groove; 270-second linear drive. DETAILED DESCRIPTION

[0028] See also Figures 1 to 7 As shown, a carrier plate 110 for negative pressure adsorption disclosed in an embodiment of the present invention is used to be arranged on the peeling platform 1.

[0029] Figures 1 to 6 The following are application examples 1( Figure 1 and Figure 2 )、Application Example 2( Figure 3 , Figure 4 and Figure 7 ) and Application Example 3( Figure 5 and Figure 6 ). The carrier plate 110 is a plate having a carrying surface 110a and a bottom surface 110b. The carrier plate 110 is used for placing a thin-film product thereon. The thin-film product may be a thinned wafer (wafer 3 combined with a carrier substrate 4), or other wafer semi-finished products / finished products.

[0030] like Figures 1 to 7 As shown, a gas channel 110c is formed inside the carrier 110, connecting the carrying surface 110a and the bottom surface 110b, and the gas channel 110c forms a plurality of ventilation openings 110d on the carrying surface 110a. The thermal conductivity characteristic of the carrier 110 is that the thermal conductivity (k value) is greater than 100W / mK (k>100WmK); wherein the aforementioned physical units include: W is watt, m is meter, and K is the absolute temperature scale. Specifically, the carrier 110 is connected to the heating device 120. The heating device 120 can be an electric heating wire, a ceramic electric heating tube, etc., fixed to the bottom surface 110b or connected to the bottom surface 110b of the carrier 110 through a heat-conducting component (such as a metal rod, a metal block). The heating device 120 can quickly heat the carrier 110. The large thermal conductivity k>100WmK helps to quickly increase the temperature of the carrier 110 and accelerate the process of stripping the carrier substrate 4. At the same time, the large thermal conductivity makes the temperature distribution on the carrier 110 more uniform, thereby avoiding the problem of excessive temperature gradient on the carrier 110 causing the thinned wafer to be heated unevenly and cracked.

[0031] In addition, the total opening area (C) of the vent opening 110d on the carrying surface 110a is less than 50% of the area (A) of the carrier 110 on the carrying surface 110a, and greater than 0.2% of the area (A) of the carrier 110 (50%*A>C>0.2%*A), that is, the opening ratio (OA) of the carrying surface 110a is: 50%>OA>0.2%. The vent opening 110d refers to the hole and the concave portion formed in the gas channel 110c on the carrying surface 110a, including the groove and the groove portion extending horizontally on the carrying surface 110a, and is not limited to the hole that penetrates the carrier 110 and connects the carrying surface 110a and the bottom surface 110b.

[0032] like Figure 1 and Figure 2As shown, the material of the carrier 110 of Application Example 1 is a porous medium, and the gaps of the porous medium are at least partially connected to form a gas channel, so that air can pass between the carrier surface 110a and the bottom surface 110b. The porous medium can be a sintered material, such as SiC, and the powder of the sintered material is heated at a high temperature so that the powder is combined to form the carrier 110. SiC has a higher thermal conductivity and oxidation resistance than general ceramic materials. Sintered materials do not exclude metals, that is, the carrier 110 can be manufactured through a powder metallurgy process. It should be noted that the opening ratio (OA) of 50%>OA>0.2% refers to the opening ratio (OA) of the carrier surface 110a, that is, the proportion of the portion on the carrier surface 110a that does not constitute a plane, rather than the overall porosity of the porous medium.

[0033] like Figure 3 and Figure 4 As shown, the material of the carrier 110 of Application Example 2 is airtight, such as metal. The carrier 110 also includes a plurality of through holes, which connect the carrier surface 110a and the bottom surface 110b to serve as gas channels 110c. At the same time, the through holes are the gas channels 110c of Application Example 2, and the through holes form the plurality of ventilation openings 110d on the carrier surface 110a.

[0034] like Figure 5 and Figure 6 As shown, the material of the carrier 110 of Application Example 3 is airtight, such as metal. The carrier 110 also includes a plurality of through holes and grooves 114, and the plurality of through holes connect the carrier surface 110a and the bottom surface 110b to serve as gas channels 110c. The grooves 114 extend on the carrier surface 110a and extend to at least one through hole. The through holes and grooves 114 together form the plurality of ventilation openings 110d on the carrier surface 110a.

[0035] See also Figure 7 , Figure 8 and Fig. 9 As shown, based on the above wafer thinning carrier 110 , the present invention provides a wafer thinning stripping platform 1 . The stripping platform 1 includes a base 210 , a carrying device 220 , a cooling plate 230 and a carrier substrate stripping device 240 .

[0036] like Figure 7 and Figure 8 As shown, two movable guide members 250 are disposed on two opposite sides 212 of the base 210 , and a guide groove 252 is disposed on the movable guide member 250 . The carrying device 220 is disposed on the base 210 and is located between the two movable guide members 250 .

[0037] like Figure 7 and Figure 8As shown, the carrying device 220 has a carrying platform 222, an adsorption assembly 223, the aforementioned wafer thinning tray 110, and a plurality of ejector pins 224. The tray 110 is used for placing the wafer 3 to be peeled and its carrier substrate 4 on its carrying surface 110a.

[0038] like Figure 7 , Fig. 9 and Fig.10 As shown, a mounting groove 222a is provided on the top surface of the carrier 222, for the carrier 110 to be raised and lowered thereon. The mounting groove 222a is a shallow groove, and the carrier 110 faces the mounting groove 222a with the bottom surface 110b, and the depth of the mounting groove 222a is substantially the same as the thickness of the carrier 110. The top surface of the carrier 222 may also be free of the mounting groove 222a, so that the carrier 110 can be directly raised and lowered on the top surface of the carrier 222. The carrier 222 is provided with a heater 225 such as an electric heating tube to heat the carrier 110, and indirectly heat the wafer 3 and the carrier substrate 4 placed on the carrier 110.

[0039] like Figure 7 , Fig. 9 and Fig.10 As shown, the adsorption component 223 and the top rod 224 are disposed in the mounting groove 222a. The adsorption component 223 can be a vacuum adsorption hole 223a connected to the air extraction device and an air guide groove 223b connected to the vacuum adsorption hole to generate negative pressure.

[0040] like Figure 7 , Fig. 9 and Fig.10 As shown, the top rod 224 is disposed in the mounting groove 222a. The bottom surface 110b of the carrier 110 is directly or indirectly connected to the top rod 224, and the bearing surface 110a faces upward. A plurality of top rods 224 are movably disposed on the carrier platform 222, and can rise or fall relative to the carrier platform 222 to lift or lower the carrier 110. That is, the carrier 110 is movably disposed in the mounting groove 222a of the carrier platform 222.

[0041] like Fig.10 As shown, when the plurality of push rods 224 descend relative to the carrier 222, the carrier 110 descends to the mounting groove 222a, and the bottom surface 110b is attached to the mounting groove 222a. At this time, the vacuum adsorption hole 223a is evacuated by the exhaust device, and the vacuum adsorption hole 223a and the air guide groove 223b connected to the vacuum adsorption hole 223a can generate negative pressure to attract airflow through the carrier, and generate negative pressure on the bearing surface of the carrier, so as to adsorb the wafer 3 and the carrier substrate 4 placed on the carrier 110. At this time, the heater 225 is used to heat the carrier 222, so that the wafer 3 and the carrier substrate 4 can be indirectly heated through the carrier 110.

[0042] like Figure 7 and Figure 8 As shown, the cooling plate 230 is disposed on the base 210 and is located between the two movable guides 250. The cooling plate 230 is adjacent to the carrier device 220 for placing the carrier substrate 4 to be cooled thereon.

[0043] like Figure 7 and Figure 8 As shown, the carrier substrate peeling device 240 includes a moving seat 242 and a vacuum suction cup 244. The moving seat 242 includes two pillars 2421 and a bracket 2422 connecting the two pillars 2421. The two pillars 2421 are respectively inserted into two guide grooves 252 so that the moving seat 242 is movably combined with the moving guide member 250, so that the moving seat 242 can move relative to the base 210 in a long axis direction. At the same time, the peeling platform 1 also includes a first linear driver 260, which is disposed on the base 210 and connected to the moving seat 242, especially connected to one of the two pillars 2421.

[0044] like Figure 7 and Figure 8 As shown, the vacuum suction cup 244 is movably disposed on the bracket 2422 of the movable seat 242, and is connected to the bracket 2422 through the second linear actuator 270. The vacuum suction cup 244 is used to be adsorbed on the carrier substrate 4, and the second linear actuator 270 is used to drive the vacuum suction cup 244 to move toward the base 210 (descend) or away from the base 210 (ascend). At the same time, the second pillar 2421 driven by the first linear actuator 260 moves along the guide groove 252, which can drive the vacuum suction cup 244 to move along the long axis direction.

[0045] See also Figures 8 to 15 As shown, it is the process of peeling the carrier substrate 4 from the wafer 3. There is an adhesive on the surface of the carrier substrate 4, and the wafer 3 is first temporarily attached (bonded) to the carrier substrate 4. The carrier substrate 4 can be but is not limited to a glass substrate, and the carrier substrate 4 is used to enhance the mechanical strength of the wafer 3. The wafer 3 is then placed in a thinning device together with the carrier substrate 4, and the surface of the wafer 3 is ground by chemical mechanical grinding or the like to reduce the thickness of the wafer 3 and flatten the surface of the wafer 3. The carrier substrate 4 enhances the mechanical strength to prevent the wafer 3 from warping during the thinning process.

[0046] like Figure 8 and Fig. 9 As shown, the multiple push rods 224 of the carrying device 220 rise first to drive the carrier 110 to rise, and the wafer 3 to be peeled and its carrier substrate 4 are moved by a robot arm or other handling equipment and placed on the carrier 110, with the wafer 3 facing the upper surface 110a of the carrier 110.

[0047] like Fig.10 and Fig.11 As shown, the top rod 224 then descends to make the upper surface 110a of the carrier plate 110 substantially flush with the carrier platform 222. Fig.10 As shown, the vacuum device evacuates the vacuum adsorption hole 223a, and generates negative pressure attraction at the vent opening 110d through the gas channel 110c to adsorb the wafer 3. At the same time, the carrier 222 also indirectly starts to heat the wafer 3 and the carrier substrate 4 through the carrier plate 110, so that the bonding structure is weakened, for example, the adhesive used for bonding is softened.

[0048] like Fig.12 and Fig.13 As shown, the second linear actuator 270 drives the vacuum chuck 244 to descend to contact the carrier substrate 4, and the vacuum chuck 244 vacuum-absorbs the carrier substrate 4. The second linear actuator 270 drives the vacuum chuck 244 to ascend to peel the carrier substrate 4 from the wafer 3.

[0049] like Fig.14 and Fig.15 As shown, the driving second pillar 2421 of the first linear actuator 260 moves along the guide groove 252, thereby moving the vacuum suction cup 244 and the carrier substrate 4 to the plate cooling plate 230, and placing the carrier substrate 4 on the cooling plate 230. At this time, the carrier substrate 4 is cooled by a cooling device disposed inside or outside the cooling plate 230, such as a liquid cooling device for liquid cooling the cooling plate 230, or an air cooling device for providing a cooling airflow to the cooling plate 230.

[0050] The carrier substrate 4 that has been cooled can be picked up by other mechanical arms or a carrier substrate peeling device and moved to the transfer plate. Similarly, the wafer 3 on the carrier plate 110 can be picked up by other mechanical arms or a carrier substrate peeling device and moved to its transfer plate.

[0051] As mentioned above, the vent openings 110d are evenly arranged on the carrying surface 110a, and can evenly adsorb the wafer 3, so that the wafer 3 is evenly stressed and will not be warped or broken when the carrier substrate 4 is peeled off. The total opening area (C) of the vent openings 110d is less than 50% of the area (A) of the carrier 110 of the carrying surface 110a, and greater than 0.2% of the area (A) of the carrier 110 (50%*A>C>0.2%*A). Therefore, sufficient and even adsorption force can be generated on the wafer 3.

[0052] By means of the negative pressure adsorption carrier 110, the negative pressure adsorption carrier device 220 and the peeling platform 1 proposed in the present invention, when fixing a thin product such as a thin wafer, a more evenly distributed negative pressure adsorption force can be applied to the thin product to avoid the thin product being subjected to concentrated force. Therefore, the present invention can effectively avoid the problem of warping and breaking of the thin product during the manufacturing process, for example, when the wafer 3 is peeled off from the carrier substrate 4.

[0053] The above is only one embodiment of the present invention and is not intended to limit the scope of the present invention. That is, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of protection requested by the present invention.

Claims

1. A carrier plate for negative pressure adsorption, the carrier plate is a plate body, including a bearing surface and a bottom surface, characterized in that: A gas channel is formed inside the carrier plate, connecting the carrier surface and the bottom surface, and the gas channel forms a plurality of ventilation openings on the carrier surface; The total opening area of ​​the plurality of ventilation openings on the carrying surface is less than 50% of the area of ​​the carrier and greater than 0.2% of the area of ​​the carrier; and The thermal conductivity of the carrier is greater than 100 W / mK, wherein W is watt, m is meter, and K is absolute temperature scale.

2. The carrier plate for negative pressure adsorption according to claim 1, characterized in that: The material of the carrier is a porous medium, and the gaps of the porous medium are at least partially connected to form the gas channel.

3. The carrier plate for negative pressure adsorption according to claim 2, characterized in that: The porous medium is a sintered material.

4. The carrier plate for negative pressure adsorption according to claim 1, characterized in that: The material of the carrier is airtight, and the carrier further comprises a plurality of through holes, the plurality of through holes communicate the carrier surface and the bottom surface to serve as the gas passage, and the plurality of through holes form the plurality of ventilation openings on the carrier surface.

5. The carrier plate for negative pressure adsorption according to claim 4, characterized in that: The carrier plate further includes a plurality of grooves extending on the carrier surface and at least extending to one through hole. The through holes and the grooves together form the plurality of ventilation openings on the carrier surface.

6. A carrying device for negative pressure adsorption, characterized in that: Included are: A bearing platform, the top surface of which has a mounting groove; and The carrier according to any one of claims 1 to 5 is movably arranged in the mounting groove of the carrier platform.

7. The carrying device for negative pressure adsorption according to claim 6, characterized in that: It also includes an adsorption component, which is arranged in the installation groove. The adsorption component is used to connect to the vacuum adsorption hole of the air extraction device and the air guide groove connected to the vacuum adsorption hole.

8. A peeling platform for peeling a wafer from a carrier substrate, characterized in that: Included are: A base having two movable guide members disposed on two opposite sides thereof; A carrying device is disposed on the base and located between the two movable guide members; the carrying device has: A bearing platform, the top surface of which has a mounting groove; and The carrier according to any one of claims 1 to 5, which is movably disposed in the mounting groove of the carrier platform, and the carrying surface is used to carry the wafer combined with the carrier substrate; A cooling plate, disposed on the base and located between the two movable guide members; The carrier substrate peeling device includes a movable seat and a vacuum suction cup; wherein the movable seat is movably coupled to the two movable guides; the vacuum suction cup is movably arranged on the movable seat for adsorbing on the carrier substrate to peel the carrier substrate from the wafer and move the carrier substrate to the cooling plate of the plate cooling device.

9. The stripping platform according to claim 8, characterized in that: A guide groove is set on each of the movable guide members, and the movable seat includes two pillars and a bracket connecting the two pillars. The two pillars are respectively inserted into each of the guide grooves so that the movable seat can be movably combined with the movable guide member, and the vacuum suction cup is movably set on the bracket.

10. The stripping platform according to claim 8, characterized in that: It also includes a first linear drive and a second linear drive; the first linear drive is arranged on the base and connected to one of the two pillars, and is used to drive each of the two pillars to move along each of the guide grooves; the vacuum suction cup is connected to the bracket through the second linear drive, and is used to drive the vacuum suction cup to move toward the base or away from the base.

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