TW201801236A - Mechanical arm and a method for gripping a substrate - Google Patents

Abstract

This invention provides a mechanical arm and a method for gripping a substrate. The substrate can be taken out from a storage rejoin and put on the storage rejoin by the mechanical arm. The mechanical arm comprises a supporting disk, a contacting pad and an absorbing device mounted on the supporting disk. When the mechanical arm takes or puts the substrate, the thickness of the mechanical arm located at the storage rejoin is a sum of the thicknesses of the supporting disk and the contacting pad. Comparing our mechanical arm with a conventional mechanical arm, when our mechanical arm take or put the substrate, the mechanical arm occupies a smaller space in the storage rejoin, such that the risk of causing scratches on the substrate may be reduced without changing the precision of the mechanical arm.

Description

Method for grasping robot arm and substrate

The present invention relates to the field of semiconductor technology, and in particular, to a robot arm and a method for grasping a substrate.

Because the robotic arm can receive instructions and perform corresponding actions according to the received instructions, in the field of semiconductor manufacturing, robotic arms are usually used to transfer substrates between the substrate storage area and processing equipment to achieve automated production.

For example, during the processing of the wafer, the wafer is placed in a cassette, and a robot arm is used to grab the wafer in the cassette and transfer the wafer to a processing equipment. FIG. 1 is a schematic structural diagram of a robot arm grasping a wafer located in a cassette in the prior art. As shown in FIG. 1, the cassette 30 is provided with a plurality of card slots 31 for carrying wafers. When the robotic arm 20 is picking up and placing the wafer, it needs to align the gap between two adjacent slots 31 and move into the gap to pick up and place the wafer. However, since the distance a between two adjacent slots 31 in the cassette 10 is small, and the robot arm 20 also has a certain thickness b, the robot arm 20 may allow the The range of displacement deviation is limited. When the displacement deviation of the robot arm is too large, the problem that the robot arm scratches the wafer is extremely easy to occur. Especially with the development of the semiconductor industry, the size of the cassette tends to decrease, which will further increase the risk of the robot arm scratching the wafer. At the same time, due to the thickness limitation, the use of existing robotic arms will also be greatly restricted.

An object of the present invention is to provide a robot arm and a method for grasping a substrate, so as to improve the problem that the robot arm scratches the substrate when the substrate is picked up and placed.

In order to solve the above technical problem, the present invention provides a robotic arm through which the substrate located in the substrate storage area is taken and put, wherein the robotic arm includes: a robotic hand plate, and a contact disposed on the robotic hand plate Pad and adsorption device, the contact pad is used to support the substrate, the adsorption device is used to adsorb and fix the substrate, and when the robot arm picks up and places the substrate, the thickness of the robot arm located in the substrate storage area is the thickness of the robot hand plate And the thickness of the contact pad.

Another object of the present invention is to provide a method for grasping a substrate, including: providing a robot arm as described above, moving the robot arm to a substrate storage area, wherein the thickness of the robot arm located in the substrate storage area is mechanical The sum of the thickness of the hand plate and the thickness of the contact pad, and the contact pad is used to support the substrate; the adsorption device is used to adsorb and fix the substrate.

In the robot arm provided by the present invention, the substrate is fixed through an adsorption device to ensure that the substrate can be stably supported on the robot arm. And when the robot arm is used to pick up and place the substrate, the presence of the adsorption device does not increase the space occupied by the robot arm in the substrate storage area, so that the total thickness of the robot arm located in the substrate storage area only includes The thickness of the robot hand plate and the thickness of the contact pads reduce the space occupied by the robot arm in the substrate storage area, thereby making the range of displacement deviation that the robot arm can allow to be larger, so that the robot arm can be changed without changing. Based on the original accuracy, the risk of scratching the substrate is reduced.

Further, since the robot arm provided by the present invention occupies a small space when picking up and placing a substrate, when the space in the substrate storage area is small, for example, for a relatively small size The small cassette can cooperate with the robot arm provided in the present invention to take and place the substrate to ensure the safety of the substrate.

10‧‧‧ wafer

20‧‧‧ Robotic arm

21‧‧‧ Manipulator tray

22‧‧‧ support block

22a‧‧‧plane

22b‧‧‧plane

30‧‧‧ Cassette

31‧‧‧card slot

100‧‧‧ substrate

200‧‧‧ robotic arm

210‧‧‧ Manipulator tray

220‧‧‧ contact pad

230‧‧‧adsorption device

231‧‧‧ Suction cup

232‧‧‧Drive

200’‧‧‧ robotic arm

230’‧‧‧ Adsorption device

231’‧‧‧ Suction cup

232’‧‧‧ Vent

FIG. 1 is a schematic diagram of a structure of a robot arm grasping a wafer located in a cassette in the prior art; FIG. 2 is a schematic diagram of a structure of a wafer carried by a robotic arm in the prior art; FIG. 3 is a structure of a robotic arm in Embodiment 1 of the present invention 4 is a schematic structural diagram of a robot arm carrying a substrate in Embodiment 1 of the present invention; FIG. 5 is a schematic structural diagram of a robot arm in Embodiment 2 of the present invention; FIG. 6 is a schematic flowchart of a substrate grasping method provided by the present invention; FIG. 7 is a schematic structural diagram of grasping a substrate located in a cassette by using a robot arm provided by the present invention.

As described in the background art, in the semiconductor industry, a robot arm is generally used to pick up and place a substrate in a substrate storage area. For example, during wafer processing, the wafer is usually placed in a cassette, and the wafer is picked up and placed in the cassette by a robotic arm. However, due to the limitation of the distance a between two adjacent card slots in the cassette and the thickness b of the robotic arm, the problem that the robotic arm scratches the wafer when picking and placing the wafer is extremely easy to occur. For this reason, of course, the thickness of the robot arm can be directly reduced to increase the range of the displacement deviation that the robot arm can allow, thereby reducing the risk of the robot arm scratching the substrate. However, without changing the structure of the robot arm, the thickness of the robot arm cannot be reduced without limit.

Correspondingly, a robotic arm for grasping a wafer is taken as an example. FIG. A schematic structural diagram of a robot arm carrying a wafer. Referring to FIG. 2, the robot arm includes a robot hand plate 21 and a support block 22 provided on the robot hand plate 21. The support block 22 has a recess. The recess forms a plane 22a and a plane 22b, the plane 22a is used to support the wafer 10, and the plane 22b is used to clamp the wafer 10 to prevent the wafer from shaking. As shown in FIG. 2, the robot hand plate 21 needs to have a certain thickness b1 to ensure that it can carry the weight of the entire wafer 10; secondly, within the range of the deformation of the wafer 10, During the process, the central area of the wafer 10 will not be in contact with the robot hand plate 21, so the support block 22 also needs to have a certain thickness b2. As such, it is difficult to reduce the thickness of the robot arm 20 without changing the structure of the robot arm 20.

For this reason, the inventor of the present application provides a robot arm which can improve the problem of scratching the substrate by the robot arm on the basis of ensuring that the substrate can be supported and fixed.

The robot arm and the method for grasping the substrate provided by the present invention will be further described in detail below with reference to the drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and the scope of patent application. It should be noted that the drawings are in a very simplified form and all use inaccurate proportions, which are only used to facilitate and clearly assist the description of the embodiments of the present invention.

Embodiment one:

FIG. 3 is a schematic structural diagram of a robot arm in Embodiment 1 of the present invention, and FIG. 4 is a structural schematic diagram of a robot arm carrying a substrate in Embodiment 1 of the present invention. In this embodiment, the substrate is a wafer. As shown in FIG. 3 and FIG. 4, the robot arm 200 includes a manipulator plate 210, a contact pad 220 and an adsorption device 230 disposed on the manipulator plate 210. Wherein, the robot hand plate 210 bears the weight of the entire substrate 100 and has a certain thickness c1; the contact pad 220 is in contact with the substrate 100 The substrate is supported to reduce the contact area between the substrate 100 and the manipulator 210, and considering the deformation of the substrate 100, the contact pad 220 also needs to have a certain thickness c2; the adsorption device 230 is used for The substrate 100 is fixed by suction to prevent the substrate 100 from shaking. In addition, when the robot arm 200 picks up and puts the substrate 100 in the substrate storage area, the thickness c of the robot arm located in the substrate storage area is the sum of the thickness c1 of the robot hand tray and the thickness c2 of the contact pad.

Compared with the prior art, when the robot arm 200 provided by the present invention is used to pick up and place the substrate 100, the thickness c of the robot arm 200 located in the substrate storage area only includes the thickness c1 of the robot hand plate 210 and the thickness c2 of the contact pad, so that The space occupied by the robot arm 200 in the substrate storage area can be reduced, so that the range of the displacement deviation that the robot arm 200 can allow is larger. In this way, the original accuracy of the robot arm 200 can be reduced without reducing the original accuracy. The risk of scratching the substrate 100 is small. Further, since the robot arm 200 provided by the present invention occupies a small space when placing and placing the substrate 100, in a case where the space in the substrate storage area is small, for example, for a small-sized cassette, it can cooperate with the present invention. The robot arm 200 provided by the invention picks up and places the substrate 100 to further ensure the safety of picking and placing the substrate 100. In addition, in the robot arm 200 provided by the present invention, the substrate 100 is fixed through an adsorption device 230 to prevent the substrate 100 from shaking during the transfer process, that is, the robot arm 200 provided by the present invention can stably support the substrate 100, It can also reduce the risk of the robot arm 200 scratching the substrate 100 when selecting the substrate 100.

In this embodiment, the manipulator plate 210 may be a Y-shaped structure. Contact pads 220 are provided on three vertices of the Y-shaped structure, and an adsorption device 230 is provided on one of the vertices.

With continued reference to FIG. 3 and FIG. 4, the adsorption device 230 is a movable adsorption device, and the adsorption device 230 moves in a movement direction relative to the robot arm 200, that is, in this embodiment. When the robot arm 200 moves in the positive direction of the X axis, the corresponding adsorption device 230 moves in the negative direction of the X axis. When the robot arm 200 is used to pick up and place the substrate 100, the position of the adsorption device 230 is moved so that the adsorption device 230 is always located outside the substrate storage area, so that the adsorption device 230 can be eliminated from the robot arm 200 in the substrate storage area. The impact of footprint.

Further, the adsorption device 230 includes at least one suction cup 231 and a driving device 232 for driving the suction cup 231 to move. After the substrate 100 is carried on the robot arm 200, the driving device 232 then drives the suction cup 231 to move to the edge position of the substrate 100 to attract and fix the substrate 100. In this embodiment, the adsorption device 230 has two suction cups 231. When the substrate is suctioned and fixed, the two suction cups 231 are respectively located on the upper surface and the lower surface of the substrate 100. Further, the suction cup 231 has at least one vent hole, and is connected to a vacuum pumping device (not shown in the figure) through the vent hole, that is, the vacuum pumping device extracts the suction cup 231 and the suction cup 231 through the vent hole. The gas between the substrates 100 forms a vacuum state between the chuck 231 and the substrates 100 to realize the adsorption and fixation of the substrates 100. Preferably, the shape of the suction cup 231 matches the basic shape. For example, in this embodiment, the robot arm 200 is used for picking and placing a wafer, that is, the shape of the substrate 100 is circular, and the shape of the corresponding sucker 231 may be a circular arc. As shown in FIG. 3, the arc-shaped sucker 231 is fixed along the edge of the substrate 100 within a permissible area. The contact area g between the sucker 231 and the substrate 100 may be from the substrate 100. The range from 2 to 5 mm from the edge to the center can avoid affecting the effective area in the substrate 100, and the effective area is, for example, an area for forming a wafer in the wafer.

With continued reference to FIGS. 3 and 4, in this embodiment, four of the contact pads 220 are provided on the robot hand plate 210, and the four positions of the substrate 100 are transmitted through the four contact pads 220. The support substrate 100 is disposed so as to prevent the substrate 100 from contacting the robot hand plate 210 to prevent the robot hand plate 210 from rubbing against the lower surface of the substrate 100 and scratching the substrate. The contact pad 220 may have any shape, such as a rectangular shape, a circular shape, or an oval shape. In this embodiment, the contact pad 220 is circular. Preferably, the diameter of the circular contact pad 220 can range from 8 to 12 mm. The reason is that if the area of the contact pad 220 is too small, In the middle of the contact with the contact pad 220, a large contact stress will be generated, which will increase the formation amount of the substrate 100. If the area of the contact pad 220 is too large, the contact area with the substrate 100 will be increased accordingly. Preferably, considering the deformation of the substrate 100, the thickness of the contact pad 220 may be 1 to 2 mm, that is, the contact pad 220 has a certain thickness, so that the deformation caused by the substrate 100 may be avoided. A problem that the middle area of the substrate 100 contacts the robot hand plate 210 and is scratched by the robot hand plate 210. In addition, in order to improve the problem that the substrate may be scratched due to the friction between the contact pad 220 and the substrate, the contact pad 220 may be made of polyetheretherketone resin (Peek). On the one hand, the polyetheretherketone resin has good compression resistance, so the problem that the contact pad 220 cannot support the substrate 100 due to compression deformation does not occur; on the other hand, the polyetheretherketone resin also has a self-lubricating effect, so The contact pad 220 made of polyetheretherketone resin has a lower coefficient of friction with the substrate 100, so that the risk of the contact pad 220 scratching the substrate 100 can be reduced.

Embodiment two:

FIG. 5 is a schematic structural diagram of a robot arm according to a second embodiment of the present invention. As shown in FIG. 5, the difference from Embodiment 1 is that in this embodiment, the adsorption device 230 ′ is fixedly disposed on the robot hand plate 210 and penetrates the lower surface of the substrate 100 to fix the substrate 100. The thickness of the adsorption device 230 ′ is smaller than the thickness of the contact pad 220. That is, in this embodiment, since the adsorption device 230 'is used to adsorb the lower surface of the substrate 100, when the contact pad 220 supports the substrate 100 At the same time, the adsorption device 230 'is also located below the substrate 100 at the same time. Therefore, directly fixing the adsorption device 230' on the robot hand 210 can still achieve the adsorption function of the substrate 100, so that the robot arm 200 ' The structure is simpler. In addition, since the thickness of the adsorption device 230 ′ is smaller than the thickness of the contact pad 220, the presence of the adsorption device 230 ′ does not affect the overall thickness of the robot arm 200 ′. It is located in the substrate storage area when the base 100 is picked and placed. The thickness c of the inner robot arm 200 ′ is still the sum of the thickness c1 of the robot hand plate 210 and the thickness c2 of the contact pad 220.

Specifically, the adsorption device 230 ′ includes at least one suction cup 231 ′. Similar to the first embodiment, the suction cup 231 ′ may also be connected to a vacuum pumping device (not shown in the figure), and may be evacuated. The substrate 100 is attracted and fixed. Correspondingly, in this embodiment, at least one vent hole 232 'may be provided in the suction cup 231', and the vacuum device extracts the gas between the suction cup 230 'and the substrate through the vent hole 232'.

In addition, in this embodiment, the adsorption device 230 'adsorbs the lower surface of the substrate 100, and generally, the lower surface of the substrate 100 has little influence on the processing of the substrate 100. For example, during the processing of a wafer, the upper surface of the substrate 100 It is a main processing area when forming a wafer. Therefore, the adsorption device 230 ′ may be disposed in any region of the robot hand plate 210, for example, may be disposed in a central area of the robot hand plate 210, or may be similar to the first embodiment. The adsorption device 230 ′ is disposed on a vertex of the Y-shaped manipulator 210 and adopts a shape and size similar to those of the embodiment.

Of course, in order to further enhance the fixing strength of the adsorption device 230 ′ to the substrate 100, a plurality of suction cups 231 ′ may be provided on the robot hand plate 210, and the substrate 100 may be suction-fixed through the plurality of suction cups 231 ′ respectively. . Alternatively, the area of the chuck 231 'can be increased to increase the fixing strength to the substrate 100 and the like.

In addition, according to the robot arm described above, the present invention also provides a grasping base Plate method. FIG. 6 is a schematic flowchart of a substrate grabbing method provided by the present invention. As shown in FIG. 6, the substrate grabbing method includes: Step S01, providing a robot arm as described above, and moving the robot arm to In the substrate storage area, the thickness of the robot arm located in the substrate storage area is the sum of the thickness of the robot hand plate and the thickness of the contact pad, and the contact pad in the robot arm is used to support the substrate to be selected; step S02, using The suction device sucks and fixes the substrate.

Compared with the traditional method of grasping a substrate by a robotic arm, in the substrate grasping method provided by the present invention, the thickness of the robotic arm moved to the substrate storage area only includes the thickness of the robotic hand tray and the thickness of the contact pad, so The space occupied by the robot arm in the substrate storage area is relatively small, that is, the range of the displacement deviation that the robot arm can allow when picking up and placing the substrate is correspondingly increased, so that the positioning accuracy of the robot arm can not be changed. , Improve the problem that the robot arm scratches the substrate. In addition, the method for grasping a substrate provided by the present invention further includes using an adsorption device to adsorb and fix the substrate, so as to ensure that the substrate can be stably supported during the transfer process.

Taking the substrate in the cassette as an example, the method for grasping the substrate provided by the present invention is described in further detail below. FIG. 7 is a schematic structural diagram of grasping a substrate located in a cassette by using a robot arm provided by the present invention.

As shown in FIG. 6 and FIG. 7, in step S01, the robot arm 200 is moved into the cassette 30 and the contact pad 220 is used to support the substrate 100. The cassette 30 is provided with a plurality of clamping slots 31 for carrying the substrate 100. Specifically, the robot arm 200 moves to the gap between two adjacent slots 31 in the X direction, and the height of the robot arm 200 can be adjusted to make the contact pad 220 on the robot arm 200 contact and support the substrate 100.

As described in the background art, with the development of the semiconductor industry, the size of the cassette 30 tends to decrease, wherein, according to the distance between two adjacent slots 31 in the cassette 30 (slot pitch) a Different, there are many different cassettes. For example, there are currently at least a cassette having a slot pitch a of 4.5 mm and a cassette having a slot pitch a of 7.5 mm. For a cassette with a card slot pitch a of 4.5 mm, when a conventional robotic arm is used to pick and place a wafer, it will easily cause the problem of scratching the substrate. For details, please refer to FIG. 2. In order to ensure that the conventional robot arm 20 can bear the weight of the entire wafer and has the function of supporting and fixing the wafer, the robot arm plate 21 and the support block 22 of the robot arm 20 both need to have A certain thickness, and when picking up and placing a wafer, the robot hand plate 21 and the support block 22 need to enter the cassette 30. The thickness of the robot arm 21 is usually 2 mm, and the thickness of the support block 22 is usually 2.3 mm. That is, the total thickness of the robot arm 20 that needs to enter the cassette 30 is 4.3 mm. It can be seen that compared to a cassette with a slot a of only 4.5mm, the range of the displacement deviation that can be generated by the traditional robotic arm 20 when picking up and placing a wafer is only 0.2mm, so it must be extremely easy. This causes the problem that the robot arm 20 scratches the wafer. At the same time, due to the influence of the thickness and accuracy of the robot arm, the utilization rate of the cassette with the card slot pitch a of 4.5 mm is greatly limited.

However, continuing to refer to FIG. 7, in the substrate grasping method provided by the present invention, the thickness c of the robot arm 200 entering the cassette 30 only includes the thickness c1 of the robot hand 210 and the thickness c2 of the contact pad 220, Similarly, in order to ensure the weight of the entire wafer, the thickness c1 of the manipulator tray 210 is set to 2mm, and the thickness c2 of the contact pad 220 can be set to 1mm, that is, the robot arm 200 located in the cassette 30 The total thickness c is only 3 mm. In this way, for a cassette with a card slot pitch a of 4.5 mm, the range of the displacement deviation that the robot arm 200 may allow when gripping the substrate 100 is 1.5 mm, which is similar to that of a conventional robot arm. Compared with the substrate, The space occupied by the gap between the two card slots is smaller, so that the robot arm can allow a larger range of displacement deviation based on the existing alignment accuracy, thereby reducing scratches on the substrate risks of.

In step S02, an adsorption device is used to adsorb and fix the substrate. Specifically, the adsorption device may be a movable adsorption device, or may be directly fixed on the robot arm plate.

Wherein, when the adsorption device is a movable adsorption device, during the process of supporting the substrate on the robot arm 200 and removing the cassette 30, the adsorption device is moved to the edge position of the substrate to align the substrate. Adsorption and fixing are performed; when the adsorption device is fixedly disposed on a robot arm and penetrates the lower surface of the adsorption substrate to fix the substrate, the adsorption device can adsorb and fix the substrate while the contact pad contacts and supports the substrate.

The embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts between the embodiments, refer to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part may refer to the description of the method.

The above-mentioned embodiments merely illustrate the principle of the present invention and its effects, but are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field to which they belong without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the scope of patent application of the present invention.

100‧‧‧ substrate

200‧‧‧ robotic arm

210‧‧‧ Manipulator tray

220‧‧‧ contact pad

230‧‧‧adsorption device

231‧‧‧ Suction cup

232‧‧‧Drive

Claims (15)

A robotic arm is used to pick and place a substrate in a substrate storage area through the robotic arm. The robotic arm includes: a robotic hand tray; a contact pad and an adsorption device provided on the robotic hand tray; The contact pad is used to support the substrate, and the adsorption device is used to adsorb and fix the substrate. When the robot arm picks up and places the substrate, the thickness of the robot arm located in the substrate storage area is the mechanical thickness of the robot. The sum of the thickness of the hand plate and the thickness of the contact pad. The robot arm according to claim 1, wherein the adsorption device is a movable adsorption device, and when the robot arm picks up and puts the substrate, the adsorption device moves to the outside of the substrate storage area. The robot arm according to claim 2, wherein the suction device includes at least one suction cup and a driving device for driving the movement of the suction cup, and the suction cup is moved to an edge position of the substrate to suck and fix the substrate. The robot arm according to claim 3, wherein the suction device comprises two suction cups, and when the substrate is suction-fixed, the two suction cups are respectively located on an upper surface and a lower surface of the substrate. The robot arm according to claim 3, wherein the shape of the suction cup matches the shape of the substrate. The robot arm according to claim 5, wherein the substrate is circular, and the shape of the suction cup is circular. The robot arm according to claim 3, wherein a contact area between the suction cup and the substrate is from The edge of the substrate is 2 mm to 5 mm from the center. The robot arm according to claim 1, wherein the adsorption device is fixedly disposed on the robot hand tray, and the substrate is fixed by adsorbing the lower surface of the substrate, wherein the thickness of the adsorption device is less than that of the adsorption device. The thickness of the contact pad. The robot arm according to claim 8, wherein the suction device includes a suction cup. The robot arm according to one of claims 3 or 9, wherein the suction cup has at least one vent hole and is connected to a vacuum device through the vent hole. The robot arm according to claim 1, wherein the contact pad is rectangular, circular, or oval. The robot arm according to claim 1, wherein the thickness of the contact pad is 1 mm to 2 mm. A method for grasping a substrate, comprising: providing a robot arm according to claim 1, moving the robot arm into the substrate storage area, wherein a thickness of the robot arm located in the substrate storage area is the thickness of the robot arm; The sum of the thickness of the manipulator plate and the thickness of the contact pad, and the contact pad is used to support the substrate; the adsorption device is used to adsorb and fix the substrate. The method for grasping a substrate according to claim 13, wherein the adsorption device is a movable adsorption device, and the adsorption is moved during the process of supporting the substrate on the robot arm and moving out of the substrate storage area. The device is positioned on the substrate and the substrate is fixed by suction. The method for grasping a substrate according to claim 13, wherein the adsorption device is fixedly disposed on the robot hand tray, and the thickness of the adsorption device is smaller than the thickness of the contact pad, and the adsorption device adsorbs and fixes the substrate. Describing the lower surface of the substrate.