TW202109712A - 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 present invention relates to a wafer transfer method and its equipment, in particular to a new wafer transfer method and its equipment.

The current front-end process of the semiconductor packaging process is to grind the wafers sent from the fab to a certain thickness and then cut the wafers to form multiple independent wafers, and then use a pick and place equipment and thimble equipment to take out each wafer. Place it on a corresponding position on a carrier board, and then you can start the subsequent packaging process.

The above-mentioned picking and placing equipment is coordinated with the ejector equipment for wafer transfer, wherein the ejector equipment is aligned with the wafer to be picked up, and the wafer is ejected upward, and then the wafer is vacuum sucked by the pickup and placing equipment, and then the wafer is moved And set on the corresponding position of the carrier; however, because the chips are adhered to a fixed tape with an adhesive layer, when the thimble device lifts the chip upwards, the adhesive layer is usually sticky. The wafer was damaged during the lifting process of the ejector 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 current wafer transfer methods that may cause damage to the wafers, the main purpose of the present invention is to provide a wafer transfer method and equipment.

The main technical means used to achieve the above purpose is to make the wafer transfer method include 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 chip to be picked up; (c) Lift up the chip to be picked up and pick up the chip. The bottom surface of the chip to be picked up is adhered with a local adhesive layer; (d) moving the picked up wafer to a carrier and heating the local adhesive layer on the bottom surface of the picked up wafer; and (e) Stick the picked up chip to the corresponding position of the carrier.

It can be seen from the above description that 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 wafer, the adhesive layer corresponding to the wafer to be picked up is lowered. The temperature reduces the viscosity before picking up; in this way, the bottom surface of the chip is picked up along with its corresponding adhesive layer, and then moved to a carrier, 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 increase the adhesiveness to smoothly stick to the corresponding position of the carrier.

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

It can be seen from the above description that the wafer transfer equipment of the present invention is mainly provided with a moving device on a platform. When a wafer that has been cut into multiple chips is placed on the moving device, the wafer will be first ordered to correspond to the bottom of the platform. The cooling device reduces the temperature of the adhesive layer corresponding to the chip to be picked up, reduces the viscosity of the adhesive layer corresponding to the chip to be picked up, and the moving device controls the wafer to move to the position of the ejector device under the platform; when the ejector device is aligned The chip to be picked up is accurate, that is, the chip is lifted. Since the adhesive layer on the bottom surface of the chip is less viscous, the chip can be easily picked up with a pickup device without damaging the chip.

The present invention is mainly aimed at improving the front-end 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 with a number of embodiments and drawings.

First, please refer to FIG. 1 and FIG. 2A to FIG. 2G, which are 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 adhesive layer 30 has a reduced viscosity at low temperatures and an increased viscosity at high temperatures; 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 on the inside of a frame 20, but it is not limited to this.

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

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

In step S14, move the picked up chip 11 to a carrier 60, as shown in FIG. 2F, and heat the local adhesive layer 30a on the bottom surface of the picked up chip 11 to restore or improve its 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-up wafer 11 can be moved first and then the local adhesive layer 30a can be heated, and vice versa, the local adhesive layer 30a can also be heated first, and then the picked-up wafer 11 can be moved.

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

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

The platform 41 includes a cooling area, a top crystal area and a moving device 42; wherein the moving device 42 is installed on the platform 41, and its moving range covers the cooling area and the top crystal area, and the moving device 42 The device 41 is for placing the blue glue 21 with a plurality of wafers 11 and its frame 20 thereon to move the blue glue 21 with a plurality of wafers 11 and its frame 20 to the cooling zone or the top crystal zone. . 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 above-mentioned cooling device 42 is arranged under the platform 41 and corresponds to the cooling zone, that is, corresponds 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 degrees to 2 degrees Celsius, but it is not limited to this.

The above-mentioned thimble device 44 is arranged under the platform 41 and 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 kept at a certain distance to provide negative pressure suction.

The heat source 51 is arranged on the moving path of the vacuum suction nozzle 50, and can be an infrared lamp or a heating device; in this embodiment, the heat source 51 provides a heating temperature of 110 to 150 degrees Celsius, but is 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, and the blue glue 21 and its The frame body 20 is set on the moving device 42 of the platform in the above-mentioned wafer transfer equipment 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 be picked up to the second opening 412 aligned with the platform 41, so that the ejector pin 441 of the ejector device 44 is aligned with the bottom surface of the wafer 11 to be picked up, and the blue glue 21 and the adhesive layer are lifted 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 released; then, as shown in FIG. 2F, the vacuum nozzle 50 moves to a carrier 60 after sucking the wafer 11, before placing the wafer 11 on the carrier 60 At this time, since the adhesive layer 30a on the bottom surface of the chip 11 is cooled and has low viscosity, a heat source 51 is provided to heat the adhesive layer 30 on the bottom surface of the chip 11 to restore or further increase the viscosity of the adhesive layer. Then, it is set to the corresponding position of the carrier board 60 to be adhered to the carrier board 60 to perform the subsequent packaging process.

Referring again to FIGS. 3A to 3C, the present invention is applied to a wire bonding and packaging process, that is, as shown in FIG. 2E, when the adhesive layer 30a of the chip 11 and its bottom surface is separated from the blue glue, the vacuum nozzle 50 moves to a The circuit substrate 60', and the adhesive layer 30a on the bottom surface of the chip 11 is heated, and then the chip 11 is adhered to the corresponding position on the circuit substrate 60'; Corresponding contacts are electrically connected. In other words, in this embodiment, compared to FIGS. 2A to 2G, the wafer 11 is transferred to the circuit substrate 60', but it is 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 wafer, the adhesive layer corresponding to the wafer to be picked is lowered. Temperature reduces the viscosity of the chip before picking; in this way, the bottom surface of the chip is picked up along with its corresponding adhesive layer, and then the adhesive layer on the bottom surface of the chip is heated during the process of moving to a carrier to make the adhesive The performance is restored or improved again, so as to smoothly stick to the corresponding position of the carrier; therefore, it can avoid the pulling and damage of the jacked chip due to the high viscosity of the adhesive layer.

The above are only the embodiments of the present invention and do 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. Anyone with ordinary knowledge in the relevant technical field, Without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make slight changes or modification into equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention is 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 solutions of the present invention.

10: Wafer 11: chip 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: A flow chart of the wafer transfer method of the present invention. Figures 2A to 2G: side plan views of different steps of the transfer method corresponding to Figure 1 of the present invention. Figures 3A to 3C: side plan views of different steps of the transfer method of the present invention corresponding to those in Figure 1;

Claims (10)

A wafer transfer method includes: (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 chip to be picked up; (c) Lift up the chip to be picked up and pick up the chip. The bottom surface of the chip to be picked up is adhered with a local adhesive layer; (d) moving the picked up wafer to a carrier and heating the local adhesive layer on the bottom surface of the picked up wafer; and (e) Stick the picked up chip to the corresponding position of the carrier. The wafer transfer method according to claim 1, wherein: In this step (b), the temperature of the adhesive layer corresponding to the chip to be picked is lowered to lower than normal temperature; and In this step (d), the local adhesive layer on the bottom surface of the picked-up chip is heated to a temperature higher than normal temperature. The chip transfer method according to claim 2, wherein in the step (b), the temperature of the adhesive layer corresponding to the chip to be picked is reduced to 0°C to 2°C. 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-up wafer is heated to a temperature higher than 110 to 150 degrees Celsius. The wafer transfer method according to any one of claims 1 to 3, wherein the step (c) is to pick up the wafer by vacuum sucking the wafer. A wafer transfer equipment, including: A platform includes a cooling zone, a top crystal zone and a moving device; wherein the moving device is arranged above the platform, and its moving range covers the cooling zone and the top crystal zone; A cooling device is arranged under the platform and corresponds to the cooling zone of the platform; and A thimble device is arranged under the platform and corresponds to the cooling zone of the platform, and the thimble device is arranged side by side with the cooling device. The wafer transfer equipment described in claim 6 further includes: A vacuum suction nozzle is arranged 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 device according to claim 7 or 8, wherein the platform is formed with a second opening in the top crystal region 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 degrees to 2 degrees Celsius; and The heat source provides a heating temperature of 110 to 150 degrees Celsius.

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