Method and device for picking up and placing ultra-thin substrate chips

Abstract

The present invention discloses a method and apparatus for picking up and placing ultra-thin substrate chips. For ultra-thin chips only a few microns thick, this method involves dipping a volatile alcohol solution onto the surface of a tip, leveraging the principle of liquid surface tension to provide a holding force during chip pickup. Under a microscope, the tip, which holds the chip using surface tension, is manipulated close to the tip and the surface of the carrier on which it will be placed. The rapid spread of the solution on the carrier surface creates tension between the chip base and the carrier. The tip is then slowly lifted to place the ultra-thin substrate chip on the carrier surface. Finally, slow heating gently dries the volatile alcohol between the chip surface and the base and carrier, effectively placing the chip. This method avoids mechanical damage to ultra-thin chips only a few microns thick during mechanical pick-up and placement, providing a feasible method for effectively placing ultra-thin substrate chips in effective locations on packaging carriers.

Description

Technical Field

[0001] The present invention relates to a method and device for picking up ultra-thin substrate chips, and in particular to a method and device for picking up and placing ultra-thin substrate chips. Background Art

[0002] In the field of microwave and terahertz circuits, in order to reduce the parasitic losses caused by the substrate, it is often necessary to reduce the substrate of the chip to tens of microns or even less than ten microns. In the case of this chip thickness, after the chip is diced on the surface of the wafer, it can no longer be removed from the expanded wafer adhesive film surface using an automatic picker using the usual technical method. For such ultra-thin substrate chips, since the substrate of this type of chip only retains a few microns, its mechanical strength is not enough to support the chip suction operation in the vacuum suction nozzle. It is very easy to find chip breakage, causing the vacuum suction nozzle to be blocked and increasing the overall cost. Therefore, for this type of ultra-thin substrate chip, it is necessary to find a technical method that has lower mechanical strength to the chip during the pick-up and placement process and is conducive to actual operation. Summary of the Invention

[0003] Purpose of the invention: To address the above problems, the present invention proposes a method and device for picking up and placing ultra-thin substrate chips, which avoids the mechanical damage to ultra-thin substrate chips caused by using a machine vacuum suction head or manual chip picking during traditional chip picking and placement, thereby improving the chip processing yield.

[0004] Technical solution: The technical solution adopted by the present invention is a method for picking up and placing ultra-thin substrate chips, comprising the following steps:

[0005] (1) placing the temporary support base on which the ultra-thin substrate chip is split upside down into a temporary support material removal tank, wherein the temporary support material removal tank is filled with a temporary support material removal solution, and the ultra-thin substrate chip is sunk to the surface of the carrier located at the bottom of the temporary support material removal tank;

[0006] (2) lifting the carrier with the ultra-thin substrate chip on its surface from the solution, and drying the temporary support material remaining on the carrier and the chip surface to remove the solution;

[0007] (3) using the tip structure to dip the alcohol solution, the amount of alcohol solution dipped by the tip structure is to ensure that droplets are formed, and the droplets cover the entire end of the tip structure without dripping; moving the tip structure to a carrier carrying an ultra-thin substrate chip, operating the tip structure under a microscope to slowly approach the ultra-thin substrate chip to be picked up, and the droplet at the end of the tip structure contacts the ultra-thin substrate chip to achieve chip picking;

[0008] (4) removing the carrier, moving the chip placement carrier to the bottom of the ultra-thin substrate chip, and slowly moving the tip structure with the chip picked up close to the surface of the chip placement carrier under a microscope until the alcohol solution is observed to spread on the surface of the chip placement carrier, and then slowly lifting the tip structure, leaving the ultra-thin substrate chip attached to the surface of the chip placement carrier;

[0009] (5) Drying the alcohol solution on the ultra-thin substrate chip to achieve placement of the ultra-thin substrate chip.

[0010] The tip structure is a probe whose end diameter is in the range of 0.5 to 1 times the size of the ultra-thin chip.

[0011] As a preferred solution of the method for picking up and placing ultra-thin substrate chips according to the present invention, the temporary support material removal solution is a toluene solution or an environmentally friendly cleaning agent.

[0012] As a preferred solution of the method for picking up and placing ultra-thin substrate chips described in the present invention, the carrier is made of dust-free paper or filter paper.

[0013] As a preferred solution of the method for picking up and placing ultra-thin substrate chips according to the present invention, the alcohol solution is anhydrous ethanol or isopropyl alcohol.

[0014] As a preferred embodiment of the method for picking up and placing ultra-thin substrate chips described in the present invention, the drying process in step (2) adopts: a drying temperature of 40-50°C and a drying time of 1-2 hours; the drying process in step (5) adopts: a drying temperature of 40-45°C and a drying time of 0.5-1 hour.

[0015] As a preferred embodiment of the method for picking up and placing ultra-thin substrate chips described in the present invention, before moving the chip placement carrier in step (4), the chip placement carrier is pretreated, and the pretreatment adopts gas plasma cleaning, the gas adopts pure argon or oxygen, and the cleaning time is 4-5 minutes.

[0016] The present invention provides a device for picking up and placing ultra-thin substrate chips, comprising: a temporary support material removal tank, an operating arm, a pick-up liquid dipping tank, a microscope, a chip placement carrier fixture, and a heating plate;

[0017] The temporary support material removal tank includes a reaction tank, a carrier and a carrier lifting device; the reaction tank is filled with a temporary support material removal solution for removing the temporary support material; the carrier is movably placed at the bottom of the container and is used to carry the ultra-thin substrate chip after the temporary support material is removed; the carrier lifting device is used to lift the carrier from the bottom of the container;

[0018] The operating arm includes a moving structure and a tip structure, and the movement of the moving structure is controlled by an operating handle;

[0019] The pickup liquid dipping tank is located below the initial position of the operating arm and is filled with an alcohol solution;

[0020] The microscope comprises a plurality of microscope lenses of different magnifications;

[0021] The chip placement carrier fixture is used to clamp the chip placement carrier;

[0022] The heating plate is used for drying the carrier, the chip placement carrier and the ultra-thin substrate chip.

[0023] The tip structure includes a probe with a terminal diameter in the range of 0.5 to 1 times the size of the ultra-thin chip, and the probe is connected to the mobile structure through a base.

[0024] As a preferred solution of the device for picking up and placing ultra-thin substrate chips described in the present invention, the device also includes a display module for converting the image captured by the microscope lens to be displayed on a display.

[0025] Beneficial Effects: Compared to existing technologies, the present invention offers the following advantages: This method utilizes liquid surface tension to pick up and place ultra-thin substrate chips. This method cleverly leverages the tension of the alcohol liquid as a pickup force on the carrier surface to achieve chip pickup. During placement, the alcohol liquid tension is again utilized to adsorb the ultra-thin substrate chip onto the chip placement carrier, drying any remaining alcohol liquid to achieve placement. The entire process is simple and easy to operate, significantly improving chip processing yield. This method avoids mechanical damage to ultra-thin chips, which are only a few microns thick, during mechanical pick-up and placement, providing a viable method for effectively placing ultra-thin substrate chips on packaging carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of the method for picking up and placing ultra-thin substrate chips according to the present invention;

[0027] Figure 2 A schematic diagram of a segmented ultra-thin substrate chip on a temporary support base;

[0028] Figure 3 Schematic diagram of ultra-thin substrate chip separation;

[0029] Figure 4 Schematic diagram of the tip structure with alcohol solution device contacting and picking up the ultra-thin substrate chip;

[0030] Figure 5 Schematic diagram of an ultra-thin substrate chip placed on a carrier surface and dried;

[0031] Figure 6This is a module diagram of the ultra-thin substrate chip pick-up and placement device of the present invention;

[0032] Description of the drawings: 1 is a temporary supporting base, 2 is an ultra-thin substrate chip, 3 is a dewaxing solution, 4 is a filter paper, 5 is a probe, 6 is an ethanol solution, and 7 is a tube shell. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1

[0035] The method for picking up and placing ultra-thin substrate chips of the present invention is as follows: Figure 1 As shown, the following steps are included:

[0036] (1) The chips are separated into thin chips on the surface of the temporary support substrate, such as Figure 2 As shown, the ultra-thin substrate chip is placed in Remover 2112 wax remover and immersed for 24 hours to remove the wax remover used to temporarily bond the ultra-thin substrate chip to the temporary support base. The separated ultra-thin substrate chip will sink to the filter paper pre-placed at the bottom of the container due to gravity;

[0037] (2) Lift the filter paper with the ultra-thin substrate chip on the bottom surface of the container from bottom to top, ensuring that the chip on the surface does not fall off during the lifting process;

[0038] (3) Place the picked-up filter paper on a hot plate at 45°C and bake for 2 hours to completely evaporate the Remover 2112 solvent remaining on the filter paper and the ultra-thin substrate chip, then cool to room temperature. Figure 3 As shown;

[0039] (4) Place the dried filter paper carrying the ultra-thin substrate chip under a microscope, and adjust the magnification of the microscope so that the ultra-thin substrate chip on the surface of the filter paper can be observed at a farther focal length. Take another carrier with a pointed tip, such as a pointed probe, and ensure that the size of the tip is close to the size of the ultra-thin substrate chip. After dipping the tip of the probe in a small amount of ethanol solution, manually place it under a microscope and slowly touch the filter paper surface to pick up a single ultra-thin substrate chip. Due to the tension of the ethanol solution at the probe tip, the ethanol solution will quickly cover the chip surface, thereby realizing the picking force between the probe tip and the chip surface, such as Figure 4 As shown;

[0040] (5) The carrier where the chip is to be placed is first cleaned with pure argon plasma at a power of 100W for 4 minutes to increase the activation of the carrier surface and improve liquid wettability. The pretreated carrier is also placed under a microscope, and the probe with the ultra-thin chip picked up by the ethanol liquid in the previous step is slowly moved to the position on the carrier surface to be placed, and the chip is slowly lowered until the chip is observed to be in contact with the substrate under the microscope, and the ethanol solution wrapped in the chip is spread on the contacting carrier surface under the action of tension; after observing the phenomenon in the previous step, the probe tip is slowly lifted manually to break the liquid adhesion between the tip-ethanol-chip, so that the chip is attached to the carrier surface under the action of the surface tension of the ethanol solution;

[0041] (6) Place the carrier with the ultra-thin substrate chip attached in the previous step on a hot plate at 40°C and bake for 30 minutes to evaporate the ethanol solution on the surface and bottom of the chip that is in contact with the carrier, and finally form a placement contact between the chip and the carrier surface, as shown in FIG. Figure 5 As shown, preparation is completed for the subsequent further processes.

[0042] Example 2

[0043] The device for picking up and placing ultra-thin substrate chips according to the present invention is shown in the schematic diagram. Figure 6 As shown, it includes: a temporary support material removal tank, a manipulation arm, a pickup liquid dipping tank, a microscope, a chip placement carrier fixture and a heating plate;

[0044] The temporary support material removal tank includes a reaction tank, a carrier, and a carrier lifting device; the reaction tank is filled with a temporary support material removal solution for removing the temporary support material; the carrier is movably placed at the bottom of the container for carrying the ultra-thin substrate chip after the temporary support material is removed; the carrier lifting device is used to lift the carrier from the bottom of the container. The operating arm includes a moving structure and a tip structure, and the movement of the moving structure is controlled by an operating handle. The pickup liquid dipping tank is located below the initial position of the operating arm, and the tank is filled with an alcohol solution. The microscope includes multiple microscope lenses of different magnifications for magnifying the field of view to move the operating arm to the desired position. The chip placement carrier fixture is used to clamp the chip placement carrier, which is a structure for placing the ultra-thin substrate chip picked up by the tip structure. The chip placement carrier can be an external mounting carrier structure. The heating plate is used to dry the carrier, chip placement carrier, and ultra-thin substrate chip.

[0045] The tip structure includes a probe with a terminal diameter in the range of 0.5 to 1 times the size of the ultra-thin chip, and the probe is connected to the mobile structure through a base.

[0046] The device also includes a display module for converting the image collected by the microscope lens to be displayed on a display.

Claims

1. A method for picking up and placing ultra-thin substrate chips, characterized in that: The following steps are involved: (1) placing the temporary support base on which the ultra-thin substrate chip is split upside down into a temporary support material removal tank, wherein the temporary support material removal tank is filled with a temporary support material removal solution, and the ultra-thin substrate chip is sunk to the surface of the carrier located at the bottom of the temporary support material removal tank; (2) lifting the carrier with the ultra-thin substrate chip on its surface from the solution, and drying the temporary support material remaining on the carrier and the chip surface to remove the solution; (3) Dipping the tip structure into an alcohol solution, wherein the amount of alcohol solution dipped into the tip structure is sufficient to form a droplet, and the droplet covers the entire end of the tip structure without dripping; Move the tip structure to the carrier carrying the ultra-thin substrate chip, operate the tip structure slowly close to the ultra-thin substrate chip to be picked up under a microscope, and pick up the chip by contacting the ultra-thin substrate chip with the droplet at the end of the tip structure; (4) removing the carrier, moving the chip placement carrier to the bottom of the ultra-thin substrate chip, and slowly moving the tip structure with the chip picked up close to the surface of the chip placement carrier under a microscope until the alcohol solution is observed to spread on the surface of the chip placement carrier, and then slowly lifting the tip structure, leaving the ultra-thin substrate chip attached to the surface of the chip placement carrier; (5) Drying the alcohol solution on the ultra-thin substrate chip to achieve placement of the ultra-thin substrate chip.

2. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: The temporary support material removal solution is a toluene solution or an environmentally friendly cleaning agent.

3. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: The carrier is made of dust-free paper or filter paper.

4. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: The tip structure is a probe with a terminal diameter in the range of 0.5 to 1 times the size of the ultra-thin chip.

5. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: The alcohol solution is anhydrous ethanol or isopropyl alcohol.

6. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: The drying process in step (2) adopts: drying temperature 40-50° C., drying time 1-2 hours; the drying process in step (5) adopts: drying temperature 40-45° C., drying time 0.5-1 hour.

7. The method for picking up and placing ultra-thin substrate chips according to claim 1, wherein: Before moving the chip placement carrier in step (4), the chip placement carrier is pretreated, and the pretreatment adopts gas plasma cleaning, and the gas adopts pure argon or oxygen, and the cleaning time is 4-5 minutes.

8. A device for picking up and placing ultra-thin substrate chips, characterized in that: include: Temporary support material removal tank, operating arm, pick-up liquid dipping tank, microscope, chip placement carrier fixture and heating plate; The temporary support material removal tank includes a reaction tank, a carrier and a carrier lifting device; the reaction tank is filled with a temporary support material removal solution for removing the temporary support material; the carrier is movably placed at the bottom of the container and is used to carry the ultra-thin substrate chip after the temporary support material is removed; the carrier lifting device is used to lift the carrier from the bottom of the container; The operating arm includes a moving structure and a tip structure, and the movement of the moving structure is controlled by an operating handle; The pickup liquid dipping tank is located below the initial position of the operating arm and is filled with an alcohol solution; The microscope comprises a plurality of microscope lenses of different magnifications; The chip placement carrier fixture is used to clamp the chip placement carrier; The heating plate is used for drying the carrier, the chip placement carrier and the ultra-thin substrate chip.

9. The device for picking up and placing ultra-thin substrate chips according to claim 8, characterized in that: The tip structure includes a probe with a terminal diameter in the range of 0.5 to 1 times the size of the ultra-thin chip, and the probe is connected to the moving structure through a base.

10. The device for picking up and placing ultra-thin substrate chips according to claim 8, wherein: The device also includes a display module for converting the image collected by the microscope lens to be displayed on a display.

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