TWI691013B - Chip picking and placing method and equipment - Google Patents

Abstract

The present invention relates a chip picking and placing method and equipment thereof. In the picking and placing method, an adhesive with viscosity that is proportional to temperature is required and multiple chips are mounted on a carrier through the adhesive. Before one of the chips is picked up, the adhesive is cooled down to decrease the viscosity thereof. Then, when the chip is picked up, a part of the adhesive mounted on a bottom of the picked chip is also picked up at the same time. The picked chip is moved to another carrier and a heating source on a moving path heats the part of the adhesive on the bottom of the picked chip to increase the viscosity thereof. Therefore, the picked chip is mounted on a corresponding position on the carrier through the part of the adhesive on the bottom thereof again.

Description

Wafer transfer method and equipment

The invention relates to a wafer transfer method and equipment, in particular to a new wafer transfer method and equipment.

At present, the first stage of the semiconductor packaging process is to grind the wafers sent from the fab to a certain thickness and then cut the crystals to form multiple independent wafers, and then take out each wafer with a pick and place device and a thimble device. Place it in the corresponding position of a carrier board, and then you can start to enter the packaging process in the later stage.

The above picking and placing equipment cooperates with the thimble equipment to carry out wafer transfer, wherein the thimble equipment will align the wafer to be picked up and eject the wafer upward, and then the vacuum is sucked by the picking and placing equipment to move the wafer And set on the corresponding position of the carrier board; however, because the chips are adhered to a fixed tape with an adhesive layer, when the thimble device lifts the wafer upward, the adhesive layer is more viscous, which usually causes The wafer is damaged during the lifting of the thimble device.

Therefore, it is necessary to improve the current wafer transfer method and related equipment to avoid damage during the wafer transfer process.

In view of the fact that the current wafer transfer method will cause damage to the wafer, the main object of the present invention is to provide a wafer transfer method and its equipment.

The main technical means used to achieve the above purpose is that the wafer transfer method includes the following steps: (a) Obtain a wafer that has been cut into multiple chips, and the chips are adhered to an adhesive layer, and the viscosity of the adhesive layer is proportional to the temperature; (b) Reduce the temperature of the adhesive layer corresponding to a wafer to be picked up; (c) The wafer to be picked up is lifted up, and the wafer is picked up, and a partial adhesive layer is adhered to the bottom surface of the picked wafer; (d) move the picked wafer to a carrier board and heat the local adhesive layer on the bottom surface of the picked wafer; and (e) Adhere the picked wafer to the corresponding position on the carrier board.

As can be seen from the above description, the wafer transfer method of the present invention uses an adhesive layer whose viscosity is proportional to the temperature to provide temporary adhesion and fixation of the wafers, and before picking up the wafers, the adhesive layer corresponding to the wafers to be picked up is reduced Temperature to reduce its viscosity before picking up; in this way, the bottom surface of the chip is picked up together with its corresponding adhesive layer, and then moved to a carrier board, and a heat source is provided on the moving path to the bottom surface of the chip The adhesive layer is heated to restore or further improve the adhesion, so as to adhere to the corresponding position of the carrier board smoothly.

The main technical means used to achieve the above purpose is that the wafer transfer equipment includes: A platform includes a cooling zone, a top crystal zone and a mobile device; wherein the mobile device is arranged above the platform, and its moving range covers the cooling zone and the top crystal zone; A cooling device is provided below the platform and corresponds to the cooling area of the platform; and A thimble device is arranged below the platform and corresponds to the cooling area of the platform, and the thimble device is arranged side by side with the cooling device.

As can be seen from the above description, the wafer transfer device of the present invention is mainly provided with a mobile device on a platform. When a wafer that has been cut into multiple chips is placed on the mobile device, the wafer will first correspond to the wafer below the platform The cooling device reduces the temperature of the adhesive layer corresponding to the wafer to be picked, reduces the viscosity of the adhesive layer corresponding to the wafer to be picked, and then the mobile device controls the wafer to move to the position of the thimble device under the platform; The wafer to be picked up is lifted up, because the adhesion of the adhesive layer on the bottom surface of the wafer is reduced, the wafer can be easily picked up with a pick-up device without damaging the wafer.

The present invention is mainly directed to the improvement of the first-stage process steps of the semiconductor packaging process, that is, the wafer transfer method and equipment. The technical content of the present invention will be described in detail below in conjunction with multiple embodiments and drawings.

First, please refer to FIGS. 1 and 2A to 2G, which is a flowchart of an embodiment of the wafer transfer method of the present invention, which includes the following steps.

In step S11, a wafer 10 that has been diced into multiple chips is obtained, as shown in FIG. 2A, and the chips 11 are adhered to an adhesive layer 30, and the temperature of the adhesive layer 30 is proportional to the viscosity That is, the viscosity of the adhesive layer 30 decreases at low temperature and increases at high temperature; in this embodiment, the chips 11 are adhered to a blue adhesive 21 through the adhesive layer 30 at normal temperature and pressure Above, the blue glue 21 is fixed inside a frame 20, but not limited to this.

In step S12, reduce the temperature of the adhesive layer corresponding to a wafer to be picked up, as shown in FIG. 2C; in this embodiment, the temperature of the adhesive layer 30a is reduced to below normal temperature, which can be reduced to about 0 to 2 degrees Celsius To make the adhesive layer 30a harden and reduce its viscosity, but not limited to this; and the cooling of the adhesive layer 30 can be partially processed, or all of them can be cooled at once.

In step S13, the wafer 11 to be picked up is lifted upward, as shown in FIG. 2E, and the wafer 11 is picked up from the adhesive layer 30, so that the lowered local adhesive layer 30a is adhered to the bottom surface of the wafer 11; in this embodiment For example, the wafer 11 is picked up by vacuum suction.

In step S14, the picked wafer 11 is moved to a carrier 60, as shown in FIG. 2F, and the local adhesive layer 30a on the bottom surface of the picked wafer 11 is heated to restore or enhance the viscosity; in this embodiment The heating temperature is higher than normal temperature, and the heating temperature can be 110 to 150 degrees Celsius, but not limited to this. In this step, the picked wafer 11 can be moved first and then the local adhesive layer 30a can be heated. On the contrary, the local adhesive layer 30a can be heated first, and then the picked wafer 11 can be moved.

In step S15, the picked wafer 11 is adhered to the corresponding position of the carrier board 60, as shown in FIG. 2G, and the wafer 11 transfer operation is completed.

Referring again to FIG. 2B, an embodiment of the wafer transfer apparatus 40 of the present invention includes a platform 41, a cooling device 43, and a thimble device 44; in addition, as shown in FIGS. 2E and 2F, it may further include A vacuum suction nozzle 50 and a heat source 51.

The platform 41 includes a cooling zone, a top crystal zone, and a mobile device 42; wherein the mobile device 42 is disposed on the platform 41, and its moving range covers the cooling zone and the top crystal zone, and the movement The device 41 is for placing the blue glue 21 and the frame 20 carrying the plurality of wafers 11 thereon to move the blue glue 21 and the frame 20 carrying the plurality of wafers 11 to the cooling area or the top crystal area . In this embodiment, the cooling zone corresponds to the first opening 411 of the platform 41, and the top crystal zone corresponds to the second opening 412 of the platform 41.

The cooling device 42 is disposed below the platform 41 and corresponds to the cooling zone, that is, to the first opening 411 of the platform 41, so as to reduce the temperature of the cooling zone. In this embodiment, the cooling device 42 provides a cooling temperature of 0°C to 2°C, but not limited to this.

The thimble device 44 is disposed below the platform 41 and is arranged side by side with the cooling device 43, that is, the thimble device 44 corresponds to the top crystal area, that is, corresponds to the second opening 411 of the platform 41, and the thimble device 44 is provided with There is at least one thimble 441, which is controlled to extend upward and pass through the second opening 412 of the platform 41.

The above-mentioned vacuum suction nozzle 50 is arranged above the platform 41, as shown in FIG. 2E, and maintains a certain distance to provide negative pressure suction.

The heat source 51 is disposed on the moving path of the vacuum suction nozzle 50, and may be an infrared lamp or a heating device thereof. In this embodiment, the heat source 51 provides a heating temperature of 110 to 150 degrees Celsius, but not limited to this.

When a wafer is adhered to a blue glue 21 with an adhesive layer 30, after grinding and cutting, as shown in FIG. 2A, a plurality of chips 11 are formed on the blue glue 21, the blue glue 21 and its The frame 20 is disposed on the moving device 42 of the platform in the wafer transfer apparatus 40. As shown in FIG. 2B, the moving device 42 aligns the position of the wafer 11 to be picked up with the first opening 411 of the platform 41. As shown in FIG. 2C, the cooling device 43 cools the local adhesive layer 30a corresponding to the wafer 11 to be picked up to reduce its viscosity; at this time, as shown in FIG. 2D, the moving device 42 on the platform 41 Move the cooled wafer 11 to the second opening 412 aligned with the platform 41, align the ejector pin 441 of the ejector device 44 with the bottom surface of the wafer 11 to be picked up, and lift the blue glue 21 and the adhesive layer upward 30 and the wafer 11 to be picked up, at the same time, a vacuum suction nozzle 50 has been aligned with the top surface of the wafer 11, and the lifted wafer 11 is sucked and moved upward, as shown in FIG. 2E, the wafer 11 Together with the corresponding local adhesive layer 30a, the blue glue is detached; then, as shown in FIG. 2F, the vacuum nozzle 50 will move to a carrier board 60 after adsorbing the wafer 11 before placing the wafer 11 on the carrier board 60 At this time, since the adhesive layer 30a on the bottom surface of the wafer 11 is cooled and the viscosity is low, a heat source 51 is provided to heat the adhesive layer 30 on the bottom surface of the wafer 11 to restore or improve the viscosity of the adhesive layer. Afterwards, it is set to the corresponding position of the carrier board 60 to be adhered to the carrier board 60 for the subsequent packaging process.

Referring again to FIGS. 3A to 3C, the present invention is applied to the wire bonding packaging process, that is, as shown in FIG. 2E, when the chip 11 and the adhesive layer 30a on the bottom surface are separated from the blue glue, the vacuum nozzle 50 moves to a The circuit substrate 60', and after the adhesive layer 30a on the bottom surface of the wafer 11 is heated, the wafer 11 is adhered to the corresponding position on the circuit substrate 60'; then, by the wire bonding process, the wafer 11 and the circuit substrate 60' The corresponding contacts are electrically connected. In other words, in this embodiment, as compared with FIGS. 2A to 2G, the wafer 11 is transferred to the circuit substrate 60', but not limited to this.

In summary, the wafer transfer method of the present invention uses an adhesive layer whose viscosity is proportional to temperature to provide temporary adhesion and fixation of the wafers, and before picking up the wafers, the adhesive layer corresponding to the wafers to be picked up is reduced Temperature to reduce the viscosity before picking up; in this way, the bottom surface of the chip is picked up together with its corresponding adhesive layer, and then moved to a carrier board to heat the adhesive layer on the bottom surface of the chip to make the adhesive It can be restored or improved again to stick to the corresponding position of the carrier board smoothly; therefore, it can avoid the damage caused by the high viscosity of the adhesive layer pulling the lifted wafer.

The above is only an embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field of the art, Within the scope of not departing from the technical solution of the present invention, when the technical contents disclosed above can be used to make some modifications or modifications to equivalent embodiments of equivalent changes, but any content that does not depart from the technical solution of the present invention, based on the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

10: Wafer 11: Wafer 20: Frame 21: Blue glue 30: Adhesive layer 40: Wafer transfer equipment 41: Platform 42: Mobile device 43: Cooling device 44: Thimble device 50: vacuum nozzle 51: heat source 60: Carrier board 61: circuit board

Figure 1: Flow chart of the wafer transfer method of the present invention. 2A to 2G: side plan views of the present invention corresponding to the different steps of the transfer method of FIG. 3A to 3C: Side plan views of the present invention corresponding to different steps of the transfer method of FIG.

Claims (10)

A wafer transfer method, including: (a) Obtain a wafer that has been cut into multiple chips, and the chips are adhered to an adhesive layer, and the viscosity of the adhesive layer is proportional to the temperature; (b) Reduce the temperature of the adhesive layer corresponding to a wafer to be picked up; (c) The wafer to be picked up is lifted up, and the wafer is picked up, and a partial adhesive layer is adhered to the bottom surface of the picked wafer; (d) move the picked wafer to a carrier board and heat the local adhesive layer on the bottom surface of the picked wafer; and (e) Adhere the picked wafer to the corresponding position on the carrier board. The wafer transfer method according to claim 1, wherein: In this step (b), the temperature of the adhesive layer corresponding to the wafer to be picked down is lower than normal temperature; and In this step (d), the local adhesive layer on the bottom surface of the picked wafer is heated to above normal temperature. The wafer transfer method according to claim 2, wherein in the step (b), the temperature of the adhesive layer corresponding to the wafer to be picked up is reduced to 0 to 2 degrees Celsius. The wafer transfer method according to claim 2 or 3, wherein in the step (d), the local adhesive layer on the bottom surface of the picked wafer is heated to 110 to 150 degrees Celsius above. The wafer transfer method according to any one of claims 1 to 3, wherein the step (c) sucks the wafer by vacuum to pick up the wafer. A wafer transfer equipment, including: A platform includes a cooling zone, a top crystal zone and a mobile device; wherein the mobile device is arranged above the platform, and its moving range covers the cooling zone and the top crystal zone; A cooling device is provided below the platform and corresponds to the cooling area of the platform; and A thimble device is arranged below the platform and corresponds to the cooling area of the platform, and the thimble device is arranged side by side with the cooling device. The wafer transfer equipment according to claim 6, further comprising: A vacuum nozzle installed above the platform; and A heat source is correspondingly arranged on the moving path of the vacuum suction nozzle. The wafer transfer apparatus according to claim 7, wherein the platform is formed with a first opening in the cooling zone to correspond to the cooling device. The wafer transfer apparatus according to claim 7 or 8, wherein the platform has a second opening formed in the top crystal area system to correspond to the ejector pin device. The wafer transfer equipment according to claim 7, wherein: The cooling device provides a cooling temperature of 0 to 2 degrees Celsius; and The heat source provides a heating temperature of 110 to 150 degrees Celsius.

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