阅读说明：本技术 一种吸盘转台和加工系统 (Sucking disc revolving stage and system of processing ) 是由 刘远航 陶红飞 付永旭 路新春 于 2021-10-28 设计创作，主要内容包括：本发明公开了一种吸盘转台和加工系统,其中吸盘转台包括：按照由上至下的顺序固定连接的吸盘、底座和轴承,以及与轴承连接的驱动机构；吸盘包括多孔盘和承载件,承载件上部具有用于容纳多孔盘的凹部；所述承载件内部设有第一通道,所述底座内部设有第二通道,用于向所述多孔盘输送流体；所述第一通道与所述第二通道通过相对的孔直接连通,以避免污染物在承载件和底座之间积聚。加工系统包括吸盘转台和磨削工具。本发明能够解决吸盘与底座之间残留磨削等污染物的问题,提高磨削稳定性以及研磨效果。(The invention discloses a sucker turntable and a processing system, wherein the sucker turntable comprises: the sucking disc, the base and the bearing are fixedly connected in sequence from top to bottom, and the driving mechanism is connected with the bearing; the suction cup comprises a porous plate and a bearing member, wherein the upper part of the bearing member is provided with a concave part for accommodating the porous plate; a first channel is arranged in the bearing piece, and a second channel is arranged in the base and used for conveying fluid to the porous disc; the first channel is in direct communication with the second channel through opposing apertures to avoid the accumulation of contaminants between the carrier and the base. The machining system includes a chuck turntable and a grinding tool. The invention can solve the problem of residual pollutants such as grinding and the like between the sucking disc and the base, and improves the grinding stability and the grinding effect.)

1. A suction cup turntable, comprising: the sucking disc, the base and the bearing are fixedly connected in sequence from top to bottom, and the driving mechanism is connected with the bearing;

the suction cup comprises a porous plate and a bearing member, wherein the upper part of the bearing member is provided with a concave part for accommodating the porous plate; a first channel is arranged in the bearing piece, and a second channel is arranged in the base and used for conveying fluid to the porous disc; the first channel is in direct communication with the second channel through opposing apertures to avoid the accumulation of contaminants between the carrier and the base.

2. The suction cup turntable of claim 1, wherein the hole for communicating the first channel with the second channel is located near the edge to increase a flow rate of the fluid supplied to the edge of the porous plate to remove contaminants that tend to accumulate at the edge.

3. The suction cup turntable of claim 2, wherein the first channel comprises a first transverse passage communicating the first transverse passage with the upper surface of the carrier to supply fluid to the porous plate, a first longitudinal passage communicating the first transverse passage with the lower surface of the carrier to communicate with the second channel.

4. The suction cup turntable of claim 3, wherein the second longitudinal passage is disposed proximate an edge of the suction cup.

5. The suction cup turntable of claim 4, wherein the first longitudinal passage comprises an edge-adjacent passage opposite the second longitudinal passage and an inboard passage, the inboard passage being remote from the edge-adjacent passage to further increase fluid flow within the edge-adjacent passage.

6. The suction cup turntable of claim 3, wherein the plurality of first transverse passageways are radially distributed.

7. The suction cup turntable of claim 3, wherein said second channel comprises a second transverse channel and a third longitudinal channel, the third longitudinal channel communicating the second transverse channel with the upper surface of the base, the third longitudinal channel communicating with said second longitudinal channel through a straight bore.

8. The suction cup turntable of claim 7, wherein the plurality of second transverse passageways are radially distributed.

9. The suction cup turntable of claim 7, further comprising a supply tube in communication with the second transverse passage.

10. A processing system, comprising:

the chuck table according to any one of claims 1 to 9, which is used for placing a workpiece thereon and is rotatable independently;

a grinding tool for grinding a workpiece.

Technical Field

The invention relates to the technical field of ultra-precise grinding of wafers, in particular to a sucker turntable and a processing system.

Background

In the semiconductor industry, electronic circuits such as ICs (Integrated circuits) and LSIs (Large Scale Integrated circuits) are formed on the surface of a semiconductor wafer to manufacture semiconductor chips. Before the wafer is divided into semiconductor chips, the back surface of the wafer opposite to the device surface on which the electronic circuits are formed is ground by a grinding and thinning apparatus, thereby thinning the wafer to a predetermined thickness.

In the thinning process, the wafer is fixed in position through the vacuum adsorption effect of the sucker turntable, and meanwhile, the flatness of the sucker turntable directly influences the thickness consistency of the wafer after grinding. In the grinding process, pollutants such as grinding water, fine grinding chips and silicon powder can be accumulated inside the sucker turntable, and local protrusions on the surface of the sucker turntable are caused after a long time, so that the consistency of wafers is poor, and the yield is low.

Disclosure of Invention

The embodiment of the invention provides a sucker turntable and a processing system, and aims to at least solve one of the technical problems in the prior art.

A first aspect of an embodiment of the present invention provides a chuck turntable, including: the sucking disc, the base and the bearing are fixedly connected in sequence from top to bottom, and the driving mechanism is connected with the bearing;

the suction cup comprises a porous plate and a bearing member, wherein the upper part of the bearing member is provided with a concave part for accommodating the porous plate; a first channel is arranged in the bearing piece, and a second channel is arranged in the base and used for conveying fluid to the porous disc; the first channel is in direct communication with the second channel through opposing apertures to avoid the accumulation of contaminants between the carrier and the base.

In one embodiment, the apertures for communicating the first and second channels are located near the edge to increase the flow of fluid to the edge of the perforated disc to remove contaminants that tend to accumulate at the edge.

In one embodiment, the first channel comprises a first transverse passage communicating the first transverse passage with the upper surface of the carrier for supplying fluid to the porous disc, a first longitudinal passage communicating the first transverse passage with the lower surface of the carrier and a second longitudinal passage communicating the first transverse passage with the lower surface of the carrier and thus with the second channel.

In one embodiment, the second longitudinal passageway is disposed proximate an edge of the suction cup.

In one embodiment, the first longitudinal channel includes an edge-proximal channel opposite the second longitudinal channel and an inboard channel distal from the edge-proximal channel to further increase fluid flow within the edge-proximal channel.

In one embodiment, the plurality of first transverse passages are radially distributed.

In one embodiment, the second passage comprises a second transverse passage and a third longitudinal passage, the third longitudinal passage communicating the second transverse passage with the upper surface of the base, the third longitudinal passage communicating with the second longitudinal passage through a directly connected orifice.

In one embodiment, the plurality of second transverse passages are radially distributed.

In one embodiment, the suction cup turret further comprises a supply tube in communication with the second lateral passage.

A second aspect of an embodiment of the present invention provides a processing system, including:

the suction cup turntable which is used for carrying the workpiece and can rotate independently;

a grinding tool for grinding a workpiece.

The embodiment of the invention has the beneficial effects that: the problem of remain pollutants such as grinding between sucking disc and the base can be solved, grinding stability and grinding effect are improved.

Drawings

The advantages of the invention will become clearer and more readily appreciated from the detailed description given with reference to the following drawings, which are given by way of illustration only and do not limit the scope of protection of the invention, wherein:

fig. 1 is a perspective view of a wafer processing system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a wafer processing system for grinding;

FIG. 3 is a schematic illustration of semi-contact grinding;

FIG. 4 is a simplified perspective view of a half-contact grinding operation;

fig. 5 is a perspective view of a chuck table according to an embodiment of the present invention;

fig. 6 is a sectional view of a chuck turntable provided in accordance with a first embodiment of the present invention;

FIG. 7 is an exploded view of the suction cup turntable of FIG. 6;

FIG. 8 is a perspective view of the suction cup of FIG. 6;

FIG. 9 is a perspective view of the base of FIG. 6;

fig. 10 is a sectional view of a chuck turntable provided in accordance with a second embodiment of the present invention;

fig. 11 is a sectional view of a chuck turntable according to a third embodiment of the present invention.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention for the purpose of illustrating the concepts of the invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In addition to the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious based on the disclosure of the claims and the specification thereof, and these technical solutions include technical solutions which make any obvious replacement or modification of the embodiments described herein. It should be understood that, unless otherwise specified, the following description of the embodiments of the present invention is made for the convenience of understanding, and the description is made in a natural state where relevant devices, apparatuses, components, etc. are originally at rest and no external control signals and driving forces are given.

Further, it is also noted that terms used herein such as front, back, up, down, left, right, top, bottom, front, back, horizontal, vertical, and the like, to denote orientation, are used merely for convenience of description to facilitate understanding of relative positions or orientations, and are not intended to limit the orientation of any device or structure.

In order to explain the technical solution of the present invention, the following description is made with reference to the accompanying drawings in combination with the embodiments.

In the present application, the workpiece may be a wafer (wafer), a chip, a silicon wafer, a substrate or a substrate (substrate), which means and actually functions equivalently. The processing system is described with reference to a wafer processing system.

Fig. 1 is a perspective view of a portion of a wafer processing system 1 according to an embodiment of the present application, the wafer processing system 1 being used for grinding a wafer, the wafer processing system 1 including:

a rotatable workbench 10 for carrying a wafer W, a sucker turntable 11 which is arranged on the workbench 10 and can be independently rotated for carrying the wafer;

a grinding tool 20 for grinding the wafer W;

and a thickness measuring device 30 for measuring the thickness of the wafer to obtain the grinding surface shape of the wafer.

Fig. 1 shows a table 10, and a plurality of chuck turntables 11 for holding and rotating a wafer are arranged on the table 10, and the wafer W is placed on the chuck turntables 11. In addition, a driving device, a support shaft system and the like are provided inside the table 10. The worktable 10 can rotate around the vertical central axis thereof so that the worktable 10 drives the plurality of sucker rotary tables 11 to integrally rotate and move, thereby realizing the position conversion of the sucker rotary tables 11 among different stations.

As a specific embodiment, as shown in fig. 1, three independently rotatable chuck turntables 11 are uniformly distributed on a worktable 10, and the three chuck turntables 11 may be completely identical in structure and function and may be implemented by porous ceramics. The centers of the three sucker rotary tables 11 and the center connecting line of the workbench 10 form an included angle of 120 degrees. The three chuck tables 11 correspond to three stations, i.e., a rough grinding station, a finish grinding station, and a loading and unloading station, wherein two stations opposite to the grinding tool 20 are used for rough grinding and finish grinding, respectively, and one station is left for loading and unloading and cleaning of wafers. The three sucker rotary tables 11 can be driven to switch among the three stations through the rotation of the workbench 10, so that the sucker rotary tables 11 can carry the wafers to circularly move according to the sequence of the loading and unloading station, the rough grinding station, the fine grinding station and the loading and unloading station. The embodiment can realize full-automatic loading and unloading and continuous grinding and cleaning of the wafer.

A grinding tool 20 is shown in fig. 1, and the grinding tool 20 includes a rough grinding portion for rough grinding the wafer W and a fine grinding portion for fine grinding the wafer W.

The rough grinding section includes a rough grinding wheel 21, a rough grinding spindle, and a rough grinding feed mechanism. The rough grinding wheel 21 is mounted at the end of the rough grinding main shaft and is driven to rotate by the rough grinding main shaft. The rough grinding main shaft is connected with the rough grinding feeding system to move up and down, so that axial plunge grinding is realized, and the wafer can reach the thickness required by the rough grinding process.

The refining section comprises a refining wheel 22, a refining spindle and a refining feed mechanism. The refiner grinding wheel 22 is mounted at the end of the refiner spindle and is driven in rotation by the refiner spindle. The fine grinding main shaft is connected with the fine grinding feeding system to move up and down, so that the axial plunge grinding is realized, and the wafer can reach the thickness required by the fine grinding process.

Also shown in fig. 1 is a thickness measuring device 30, which includes a contact thickness detecting device and a non-contact thickness detecting device, and can realize on-line monitoring of the thickness of the wafer. It should be noted that, in an embodiment of the present invention, the wafer thickness refers to the entire thickness from the upper surface to the lower surface of the wafer, rather than the thickness of the coating film laid on the wafer surface.

In addition, in the implementation, the wafer processing system 1 further includes a grinding fluid supply unit for spraying a grinding fluid, which may be deionized water, onto the wafer surface to aid grinding during rough grinding and/or finish grinding.

Fig. 2 shows the working principle of grinding using the grinding wheel and the chuck table 11, as shown in the figure, a vacuum adsorption type rotary chuck table 11 is used for grinding, a wafer is adsorbed on the vacuum chuck table 50 and is driven to rotate, the center of the wafer coincides with the center of the chuck table 11, the grinding wheel is pressed on the wafer to rotate and is fed along the axial direction F according to a certain feeding speed, and therefore the wafer is ground.

Fig. 3 and 4 show a semi-contact grinding mode adopted in the present disclosure in a schematic simplified diagram, in fig. 3, a thick black double-layer dashed line shows a position of a grinding wheel, a thin dotted line shows a position of a chuck turntable 11, and a black solid area shows a grinding area, that is, an area where the grinding wheel contacts with a wafer when the grinding wheel grinds the wafer, and two end points of the area may be a wafer center and an edge.

As shown in fig. 4, during grinding, the spindle of the grinding tool 20 and the rotation axis of the chuck table 11 have an angle θ therebetween, so that the grinding tool 20 is in contact with only a radius region of the wafer W for grinding, thereby achieving semi-contact grinding, i.e., a grinding region shown by a black solid region in fig. 3, that is, a grinding wheel is in contact with only a center-to-edge region of the wafer W for grinding.

The sucker rotary table 11 needs to realize the functions of vacuum adsorption, water vapor flushing and the like through a specific pipeline. The chuck turntable 11 comprises a chuck 50, a base 60 and a bearing 80, the chuck 50 may be made of porous ceramic, the porous ceramic may allow silicon powder and other small particles to penetrate through during a vacuum adsorption process, for example, micron-sized contaminants to be accumulated in a pipeline of the chuck turntable 11, the contaminants inevitably enter a gap between the chuck 50 and the base 60 during a water vapor flushing process and are not easily discharged, and after a long time, local protrusions are generated on the surface of the chuck 50, which may cause poor wafer consistency.

In order to solve the above problems, as shown in fig. 5 to 9, an embodiment of the present invention provides a chuck turntable 11 for wafer processing, including: the suction cup 50, the base 60 and the bearing 80 are fixedly connected in this order from the top, and a driving mechanism (not shown) is connected to the bearing 80.

The suction cup 50 comprises a porous plate 51 and a carrier 52, the carrier 52 has a recess 53 at the upper part for accommodating the porous plate 51, the carrier 52 is provided with a first channel 54 inside, and the base 60 is provided with a second channel 61 inside for conveying fluid to the porous plate 51; the first channel 54 communicates directly with the second channel 61 through opposing apertures to avoid the accumulation of contaminants between the carrier 52 and the base 60.

Wherein the number, location, shape and size of the holes interconnecting the first channel 54 and the second channel 61 are identical.

As shown in fig. 6, the second channel 61 of the base 60 is directly connected to the first channel 54 of the chuck 50, and when the chuck 50 is vacuum-sucked by the channel or the fluid is sprayed from bottom to top to the chuck 50 for rinsing, the material passing through the channel, whether solid or fluid, can only pass through the channel that is straight from top to bottom, and there is no other space for containing contaminants and no space for remaining between the chuck 50 and the base 60.

In one embodiment, the porous plate 51 and the carrier 52 constituting the suction cup 50 are tightly coupled together, e.g., glued. The upper surface of the porous plate 51 is a holding surface for holding the wafer by suction, and the porous plate 51 is made of porous ceramic or microporous ceramic to realize vacuum adsorption of the wafer. The carrier 52 has a recess 53 for exposing the holding surface and accommodating the porous plate 51, and the material of the carrier 52 is dense ceramic.

In one embodiment, the base 60 may be made of ceramic or stainless steel. The bearing 80 is an air bearing, and the suction cup 50 and the air bearing are installed through the base 60.

As shown in fig. 6 and 7, the suction cup turntable 11 further includes a supply pipe 90 communicating with the second passage 61 of the base 60, the supply pipe 90 being located below the base 60 and penetrating the bearing 80. The second passage 61 is connected to a fluid source through a supply tube 90 extending through a central bore of the bearing 80. In this embodiment, the first channel 54 and the second channel 61 are connected to the fluid source by the supply pipe 90, and the supply pipe 90 may be made of the same material as the base 60, for example, ceramic or stainless steel. In addition, an outer side surface of the supply pipe 90, which extends into the base 60 and contacts the base 60, is provided with a ring-shaped seal groove 93, in which an elastic material is provided to seal, thereby preventing fluid from flowing in or out from a gap between contact surfaces of the supply pipe 90 and the base 60, which contact each other.

Wherein, the fluid source can be a vacuum source, a gas source and/or a liquid source.

In one embodiment, the apertures for communicating the first and second channels 54, 61 are located near the edge to increase the flow of fluid to the edge of the perforated disc 51 to remove contaminants that tend to accumulate at the edge.

In one embodiment, the first channel 54 comprises a first transverse passage 55, a first longitudinal passage 56 and a second longitudinal passage 57, the first longitudinal passage 56 communicating the first transverse passage 55 with the upper surface of the carrier 52 to supply fluid to the porous disc 51, the second longitudinal passage 57 communicating the first transverse passage 55 with the lower surface of the carrier 52 and thus with the second channel 61. Wherein the plurality of first transverse passages 55 are radially distributed.

The second longitudinal passage 57 is provided near the edge of the suction cup 50.

The first longitudinal passages 56 include an edge-proximal passage opposite the second longitudinal passage 57 and an inboard passage that is distal from the edge-proximal passage to further enhance fluid flow within the edge-proximal passage.

In one embodiment, the second channel 61 comprises a second transverse channel 62 and a third longitudinal channel 63, the third longitudinal channel 63 communicating the second transverse channel 62 with the upper surface of the base 60, the third longitudinal channel 63 communicating with the second longitudinal channel 57 through a straight hole. Wherein the plurality of second transverse passages 62 are radially distributed.

Three specific examples provided by the present application are described below.

First embodiment

As shown in fig. 6 to 8, the first channel 54 inside the suction cup 50 comprises a first transverse passage 55, a first longitudinal through hole 56 and a second longitudinal passage 57 communicating. A first transverse passage 55 is provided inside the carrier 52 for communicating a plurality of first longitudinal through holes 56 and a second longitudinal passage 57. A first longitudinal through hole 56 and a second longitudinal passageway 57 extend from the first transverse passageway 55 up or down through the upper surface of the carrier 52 or the lower surface of the carrier 52.

As shown in fig. 8, the first passage 54 includes a plurality of communicating cross-type first lateral passages 55 which are multiply crossed, uniformly distributed and communicated at a central position. Each first transverse passage 55 is provided with a plurality of first longitudinal through holes 56 and second longitudinal passages 57 which are uniformly distributed, so that uniform loading vacuum or gas-liquid flushing is realized on the suction cup 50.

In one specific application, as shown in fig. 8, six first transverse passages 55 are arranged inside the suction cup 50 and distributed at equal angles, and each first transverse passage 55 is provided with 3 sets of symmetrically distributed first longitudinal through holes 56 which are communicated with the porous plate 51 upwards and 1 set of symmetrically distributed second longitudinal passages 57 which are communicated with the base 60 downwards. Further, the downward second longitudinal passages 57 correspond in position to the outermost 1 group of upward first longitudinal through holes 56.

As shown in fig. 6, 7 and 9, the second channel 61 inside the seat 60 comprises a second transverse passage 62 and a third longitudinal passage 63. A second transverse passage 62 is provided inside the seat 60 for communicating with a plurality of third longitudinal passages 63. A third longitudinal passageway 63 extends upwardly from the second transverse passageway 62 through the upper surface of the base 60 to communicate with the second longitudinal passageway 57.

As shown in fig. 9, the second channel 61 includes a plurality of communicating second transverse passages 62 of a cross type which are multiply crossed, uniformly distributed and communicated at a central position. Each second transverse passage 62 is provided with a third longitudinal passage 63 for communication with the second longitudinal passage 57.

In one specific application, as shown in fig. 9, six second transverse passages 62 are disposed inside the base 60 and are distributed at equal angles, and each second transverse passage 62 is provided with 1 set of symmetrically disposed third longitudinal passages 63 which are communicated with the second longitudinal passages 57 upward. Further, the third longitudinal passage 63 communicates with the 1 outermost group of the second longitudinal passages 57.

As shown in fig. 7 to 9, the suction cup 50, the base 60 and the bearing 80 are respectively provided with mounting holes 70, and the suction cup 50, the base 60 and the bearing 80 can be fixedly connected by using the mounting holes 70 and screws. Specifically, the first mounting hole 70a is located in the circumferential direction of the suction cup 50, the second mounting hole 70b is located in the outer circumferential direction of the base 60, the third mounting hole 70c is located in the inner circumferential direction, and the fourth mounting hole 70d is located in the circumferential direction of the bearing 80.

The first mounting hole 70a corresponds to the second mounting hole 70b, and the third mounting hole 70c corresponds to the fourth mounting hole 70 d.

Second embodiment

As shown in fig. 10, the first channel 54 inside the suction cup 50 comprises only a plurality of first longitudinal through holes 56, the plurality of first longitudinal through holes 56 may be evenly distributed inside the carrier 52, the first longitudinal through holes 56 extending directly to the lower surface of the carrier 52.

The second channel 61 inside the base 60 comprises a second transverse passage 62 and third longitudinal passages 63 communicating with the first longitudinal through holes 56 in a one-to-one correspondence, the number of the third longitudinal passages 63 being the same as the number of the first longitudinal through holes 56, all the first longitudinal through holes 56 forming passages in a one-to-one correspondence with the third longitudinal passages 63.

Third embodiment

As shown in fig. 11, the first channel 54 includes only a plurality of first longitudinal through holes 56, the first longitudinal through holes 56 penetrating the upper and lower surfaces of the carrier 52, and the second channel 61 includes second lateral passages 62 and third longitudinal passages 63 communicating with the first longitudinal through holes 56 in a one-to-one correspondence.

Further, a sealing element 66 is added at the interface of each first longitudinal through hole 56 and the third longitudinal passage 63, further preventing contaminants from diffusing between the carrier 52 and the base 60.

In addition, in one embodiment, the driving mechanism includes a pulley, a belt and a motor located below the bearing 80, the bearing 80 is connected with the pulley, the pulley is connected with the motor through the belt to realize electric rotation, and the suction cup 50 is driven to rotate through the motor control and the transmission of the belt, the pulley and the bearing 80.

In one embodiment, the chuck table 11 further comprises a swivel. The bottom end of the bearing 80 is fixed with a rotary joint, the rotary joint is connected with the supply pipe 90, and the supply pipe 90 is communicated with a fluid source through the rotary joint.

In summary, the embodiment of the present invention arranges the fluid channel inside the suction cup 50, so as to ensure the uniformity of vacuum adsorption and fluid flushing; the fluid passage between the sucker 50 and the base 60 is realized only by reducing the connecting area through straight holes and the like, the quantity and the area of the fluid passage between the contact surfaces of the sucker 50 and the base 60 can be reduced, the risk that particle impurities enter the space between the sucker 50 and the base 60 through the passage can be reduced, further, the surface deformation of the sucker 50 caused by the particle deposition between the sucker 50 and the base 60 is avoided, the wafer consistency is prevented from deteriorating gradually along with the operation of equipment, the consistency precision is kept when the wafer is ground, the frequency of surface shape finishing on the sucker 50 is reduced, the stability of the equipment is effectively improved, and the cost and the maintenance time are reduced.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of respective portions and their mutual relationships. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly show the structure of the elements of the embodiments of the invention.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.