Chip transfer device with floating positioning function and chip floating positioning method

Abstract

The present invention relates to a chip transfer device with a floating positioning function and a chip floating positioning method. Specifically, when a chip is placed in a chip placement groove, a control unit controls a pneumatic switching valve to connect at least one ventilation hole to a positive pressure source, and the air flow flowing out from the positive pressure source through the ventilation hole blows towards the lower surface of the chip, causing at least one chip to form an air float. Accordingly, when the chip placement groove is connected to the positive pressure source, gas is blown towards the lower surface of the chip in the chip placement groove through the ventilation hole, causing an air float phenomenon of the chip in the chip placement groove to reduce the error displacement of the chip offset. Once the blowing air flow is cancelled, the chip can completely fall into the chip placement groove to achieve the positioning function.

Description

Technical Field

[0001] The present invention relates to a chip transfer device with a floating positioning function and a chip floating positioning method, especially a positioning method suitable for thin chips and a transfer device using this method. Background Art

[0002] Positioning of unpackaged chips (die) has always been one of the important problems for semiconductor manufacturing equipment or test equipment manufacturers. Because the chips before packaging are quite thin, light in weight, and prone to breakage and being scrapped when under improper force, so both the picking and placing process and the transfer process are quite vulnerable to the influence of the external environment and the positioning fails.

[0003] For further illustration, please refer to FIG. 1 together, which is a schematic diagram of the existing picking and placing process of thin chips. Among them, taking the placement of chip C into chip slot Sc as an example, when picking and placing device P transfers chip C above chip slot Sc, picking and placing device P will not directly press chip C into chip slot Sc. Because once the positions of chip C and chip slot Sc are offset, the downward pressure of picking and placing device P is likely to cause chip C to be crushed. Therefore, picking and placing device P will release the suction when chip C is above chip slot Sc and at a specific height H, allowing chip C to naturally fall into chip slot Sc.

[0004] However, because chip C is extremely light in weight and quite thin in volume, and during the falling process, the air flow velocity below chip C is slow, so the pressure is relatively high; moreover, when air passes through the outer edge of chip C, vortices will be generated, and after the vortices are generated, the air pressure at that place will be reduced. Furthermore, since the vortices are alternately generated on the four side end faces of chip C, the pressures at the four side edges of chip C are inconsistent, so that chip C is prone to yaw during the falling process and it is difficult to completely fall into chip slot Sc.

[0005] However, most of the existing technologies solve the above problems by starting from the design of chip slot Sc, that is, chamfers Cf are provided at the four side edges of chip slot Sc, so that the four side end faces of chip C can slide into chip slot Sc along the chamfers Cf of chip slot Sc during the falling process. However, in the case of a large offset amount, for example, when the four side end faces of chip C exceed the chamfers Cf of chip slot Sc, chip C still cannot completely fall into chip slot Sc with the assistance of the chamfers Cf.

[0006] In addition, please refer to together Figure 1B, which is a schematic diagram of the existing thin chip C being stuck at one end on the chamfer Cf due to yaw; because both the chamfer Cf and the chip C are rigid bodies, there is friction between them, and in addition, the weight of the chip C1 itself is quite light, and its own weight is difficult to directly overcome this friction. Therefore, even if one end of the chip C happens to fall on the chamfer Cf, there is a high probability that due to the friction between the two, the chip C will be stuck on the chamfer Cf and cannot smoothly slide into the groove. Summary of the Invention

[0007] The main object of the present invention is to provide a chip transfer device and a chip floating positioning method with a floating positioning function, so that the chip can be placed quite completely and stably into the chip placement groove before, during, and even after the transfer process.

[0008] To achieve the above object, a chip transfer device with a floating positioning function of the present invention transfers at least one chip from a first position to a second position. The chip transfer device mainly includes a chip carrier, a pneumatic switching valve, and a control unit; wherein, the upper surface of the chip carrier includes at least one chip placement groove, and each chip placement groove is provided with at least one ventilation hole; in addition, the pneumatic switching valve includes a first inlet end and an outlet end, the first inlet end is connected to a positive air pressure source, and the outlet end is connected to at least one ventilation hole of the chip carrier; the control unit is electrically connected to the pneumatic switching valve and controls the pneumatic switching valve to connect at least one ventilation hole to the positive air pressure source. Wherein, when at least one chip is placed into at least one chip placement groove, the control unit controls the pneumatic switching valve to connect at least one ventilation hole to the positive air pressure source, and the air flow flowing out from the positive air pressure source through at least one ventilation hole blows towards the lower surface of at least one chip, causing at least one chip to form an air float.

[0009] As described above, the present invention connects the chip placement groove to the positive air pressure source, that is, by blowing gas towards the lower surface of the chip in the chip placement groove, causing the chip to produce a continuous floating phenomenon under the influence of the air flow; once the blowing air flow is cancelled, the chip can completely fall into the chip placement groove. Accordingly, the present invention uses the air flow to blow towards the chip to make the chip produce an air float phenomenon in the chip placement groove, so as to reduce the error displacement of the chip offset. Once the blowing air flow is cancelled, the chip can completely fall into the chip placement groove to achieve the positioning function.

[0010] Further explanation, in the present invention, the pneumatic switching valve further includes a second inlet end, which is connected to a negative air pressure source; and the control unit can first control the pneumatic switching valve to connect at least one ventilation hole to the positive air pressure source, and then control the pneumatic switching valve to connect at least one ventilation hole to the negative air pressure source. In other words, the present invention can first perform floating positioning, and after the positioning is completed, use negative pressure to vacuum adsorb the chip to firmly fix the chip in the chip placement groove.

[0011] Furthermore, when at least one chip is placed into at least one chip placement slot and the chip carrier is at the first position, the control unit can first control the pneumatic switching valve to connect at least one ventilation hole to the positive pressure source first, and then the control unit can control the pneumatic switching valve to connect at least one ventilation hole to the negative pressure source and continue until the chip carrier moves to the second position. In other words, the present invention can complete the positioning before the chip is transferred, and adsorb the chip with the negative pressure source to fix it, and then transfer the chip. Accordingly, it can also be ensured that the chip will not fall out again during the transfer process of the chip.

[0012] On the other hand, in the present invention, the pneumatic switching valve may further include a third inlet end which can be connected to the external atmospheric pressure; when at least one chip is placed into at least one chip placement slot and the chip carrier is at the first position, the control unit can control the pneumatic switching valve to connect at least one ventilation hole to the positive pressure source, the negative pressure source and the external atmospheric pressure in sequence, and then the chip carrier moves to the second position. In other words, the present invention can also complete the positioning before the chip is transferred, and does not force the application of negative pressure during the transfer process, that is, the inside of the chip placement slot is at atmospheric pressure, and the chip is fixed in the chip placement slot by its own gravity. Accordingly, there is no need to additionally provide connecting pipelines or joints for positive pressure and negative pressure on the transfer path of the chip placement slot and at the second position, making the overall device more streamlined, and the assembly and maintenance costs can be greatly reduced.

[0013] Preferably, the present invention may further include a pressure sensing unit which is electrically connected to the control unit; wherein, when the control unit controls the pneumatic switching valve to connect at least one ventilation hole to the negative pressure source, the control unit can control the pressure sensing unit to detect the gas pressure inside the chip placement slot. Once the gas pressure is higher than a predetermined value, the control unit can send a warning message or control the pneumatic switching valve to connect at least one ventilation hole to the positive pressure source again. That is, when adsorbing the chip with negative pressure, the present invention can additionally detect the gas pressure inside the chip placement slot through the pressure sensing unit, and judge whether the chip has been positioned accordingly; because if the positioning is not completed, a large amount of air leakage will occur, resulting in an increase in the gas pressure inside the chip placement slot, and the control unit can issue a warning message or perform floating positioning again.

[0014] Moreover, at least one ventilation hole of the chip carrier of the present invention can be funnel-shaped; each chip placement slot can include a chip slot part and an air storage slot part, and the horizontal cross-sectional area of the air storage slot part can be smaller than that of the chip slot part, and the air storage slot part can be located below the chip slot part, and at least one ventilation hole can be located at the bottom surface of the air storage slot part. In addition, the chip slot part can be gradually expanded towards the upper surface of the chip carrier, and the air storage slot part can also be gradually expanded towards the chip slot part, and a step part can be included between the air storage slot part and the chip slot part; wherein, the chip is placed on the step part, and the chip slot part with a gradually expanding opening can assist in chip positioning.

[0015] To achieve the above object, a method for floating positioning of a chip according to the present invention includes the following steps: First, a chip is provided to a chip placement groove, and at least one ventilation hole is opened on the bottom surface of the chip placement groove, which communicates with the outlet end of a pneumatic switching valve, and the pneumatic switching valve further includes a first inlet end communicating with a positive air pressure source; then, the pneumatic switching valve is controlled to switch so that at least one ventilation hole communicates with the positive air pressure source, and the air flow flowing out from the positive air pressure source through at least one ventilation hole blows towards the lower surface of at least one chip, causing at least one chip to form an air float.

[0016] As described above, according to the method for floating positioning of a chip provided by the present invention, first, the ventilation hole on the bottom surface of the chip placement groove is communicated with the positive air pressure source to provide an air flow to blow towards the lower surface of the chip, causing the chip to float under the influence of the air flow. Once the air flow is cancelled, the chip can smoothly and completely fall into the chip placement groove. Thus, the method provided by the present invention can ensure that the chip is completely positioned in the chip placement groove.

[0017] Moreover, the method for floating positioning of a chip provided by the present invention can further ensure that the chip does not fall out of the chip placement groove during the transfer process of the chip, that is, the chip placement groove moves from the first position to the second position, and a negative pressure can be continuously applied to the chip placement groove during the movement to make the chip more firmly accommodated in the chip placement groove; on the other hand, after the positioning is completed at the first position, the negative pressure can be no longer applied to simplify the complexity of the device and reduce the cost.

[0018] In addition, in the method provided by the present invention, when the chip placement groove is communicated with a negative air pressure source, the gas pressure in the chip placement groove is detected by a pressure sensing unit. Once the chip is not completely positioned and a large amount of air flows into the chip placement groove, resulting in the gas pressure being higher than the predetermined value, the at least one ventilation hole can be communicated with the positive air pressure source again, that is, floating positioning is performed again. Of course, it is not limited to floating positioning again, and a warning message can also be directly sent. Description of the Drawings

[0019] Figure 1A It is a schematic diagram of the process of picking and placing an existing thin chip.

[0020] Figure 1B It is a schematic diagram of an existing thin chip with one end stuck on a chamfer due to friction caused by yaw.

[0021] Figure 2 It is a system architecture diagram of the first embodiment of the present invention.

[0022] Figure 3 It is a transfer schematic diagram of the first embodiment of the present invention.

[0023] Figure 4AIt is a perspective view of the chip carrier of the present invention.

[0024] Figure 4B It is a partial cross-sectional view of the chip placement groove of the present invention.

[0025] Figure 4C It is a partial cross-sectional view of the chip placement groove of the present invention, which shows the chip floating phenomenon caused by air flow in the groove.

[0026] Figure 5A It is a perspective view of another embodiment of the chip placement groove of the present invention.

[0027] Figure 5B It is a partial cross-sectional view of another embodiment of the chip placement groove of the present invention.

[0028] Figure 6 It is a system architecture diagram of the second embodiment of the present invention. Detailed implementation

[0029] Before the chip transfer device and the chip floating positioning method with floating positioning function of the present invention are described in detail in this embodiment, it should be particularly noted that in the following description, similar components will be represented by the same component symbols. Furthermore, the drawings of the present invention are only for illustrative purposes, and they may not be drawn to scale, and not all details may be presented in the drawings.

[0030] Please refer to Figure 2 and Figure 3 , Figure 2 is the system architecture diagram of the first embodiment of the present invention, Figure 3 is the transfer schematic diagram of the first embodiment of the present invention. As shown in the figure, the chip transfer device of this embodiment mainly includes a chip carrier 2, a pneumatic switching valve 3 and a control unit 4. Among them, the chip carrier 2 of this embodiment can be a shuttle for transferring chips in a chip detection device, such as Figure 3 shown, which can move between the first position P1 and the second position P2; and the first position P1 is the position for loading chips, that is, through the pick&place device D p to transfer the chip C to be tested from the chip carrier tray (not shown in the figure) to the chip carrier 2. In addition, the second position P2 is the test position, that is, the position where the upper test head T h presses down to contact the chip C to be tested and performs the test.

[0031] Furthermore, please refer to Figure 4A and Figure 4B , Figure 4A is the perspective view of the chip carrier of the present invention, Figure 4Bis a partial cross-sectional view of the chip carrier of the present invention; the upper surface 20 of the chip carrier 2 in this embodiment includes a plurality of chip placement grooves 21, and each chip placement groove 21 is provided with a vent hole 210. In this embodiment, each chip placement groove 21 includes a chip groove portion 211 and an air storage groove portion 212. The air storage groove portion 212 is located below the chip groove portion 211, and the vent hole 210 is located at the bottom surface of the air storage groove portion 212; moreover, the horizontal cross-sectional area of the air storage groove portion 212 is smaller than that of the chip groove portion 211, so the step difference between the two forms a step portion 213, whereby the chip C can be placed and supported.

[0032] In addition, the chip groove portion 211 of this embodiment is gradually expanding towards the upper surface 20 of the chip carrier 2, and the air storage groove portion 212 is gradually expanding towards the chip groove portion 211; that is to say, the openings of the air storage groove portion 212 and the chip groove portion 211 towards the upper side are both gradually expanding. Among them, the intention of the air storage groove portion 212 and the chip groove portion 211 having gradually expanding openings is to facilitate guiding the airflow, so that the blowing airflow can evenly dissipate towards the four side edges. In addition, the gradually expanding opening of the chip groove portion 211 can also assist in positioning to guide the chip C to fall into the chip groove portion 211.

[0033] Furthermore, the air pressure switching valve 3 in this embodiment is a solenoid valve, which includes a first inlet end 31, a second inlet end 32 and an outlet end 33, and the first inlet end 31 is connected to the positive air pressure source P Pos , the second inlet end 32 is connected to the negative air pressure source P Neg , and the outlet end 32 is connected to the vent hole 210 of the chip carrier 2. In addition, the control unit 4 in this embodiment can be an independent programmable logic controller (PLC), or can be the main controller of the entire test equipment. It is electrically connected to the air pressure switching valve 3 and controls the air pressure switching valve 3 to make the vent hole 210 communicate with the positive air pressure source P Pos or the negative air pressure source P Neg . In other words, the control unit 4 can control the air pressure switching valve 3 to switch the outlet end 33 to communicate with the first inlet end 31 or the second inlet end 32 to perform blowing or suction.

[0034] The operation method of this embodiment is described in detail below. First, when the chip carrier 2 is located at the first position P1, the picking and placing device D p moves the chip C to be tested from the chip carrier tray (not shown in the figure) to the chip carrier 2 and places the chip C corresponding to the chip placement groove 21; then, the control unit 4 first controls the air pressure switching valve 3 to make the vent hole 210 communicate with the positive air pressure source P Pos , so the air flow will spray upward from the vent hole 210 and blow towards the chip C, thereby making the chip C produce the effect of air floating and micro-movement. Please see Figure 4C , Figure 4CIt is a partial cross-sectional view of the chip placement groove of the present invention, which shows the chip floating phenomenon caused by air flow in the groove.

[0035] Specifically, the blowing air flow in this embodiment makes the chip C float. In addition to helping the chip C to be centered, as Figure 4C shown, since the blowing air flow continuously flows out from the four side edges of the chip C, and the air flow itself just forms an excellent lubricating fluid, it can eliminate the rigid surface friction between the chip C and the gradually expanding opening (chamfer) of the chip groove portion 211, so that the chip C can smoothly and completely slide into the chip groove portion 211. In this embodiment, the chip C to be transferred is a CMOS chip. The blowing air pressure only needs to be between 2 kPa and 4 kPa, and the size of the CMOS chip is 7.3 mm × 6.5 mm.

[0036] Furthermore, after blowing for several seconds, the control unit 4 controls the air pressure switching valve 3 to connect the vent hole 210 to the negative air pressure source P Neg , so as to generate negative pressure in the air storage groove portion 212 of the chip placement groove 21 to adsorb the chip C. In other words, after the floating positioning step, once the blowing is cancelled, the chip C can completely fall into the chip groove portion 211 of the chip placement groove 21. Then, through the negative air pressure source P Neg to generate suction force to firmly fix the chip C to the chip placement groove 21. Finally, the chip carrier 2 is controlled to move to the second position P2. However, during the entire transfer process, the negative air pressure source P Neg is always connected to the vent hole 210, so the chip placement groove 21 always adsorbs the chip C to ensure that the chip C will not come out again during the transfer process of the chip C.

[0037] Please refer to Figure 5A and Figure 5B , Figure 5A which is a perspective view of another embodiment of the chip placement groove 21 of the present invention, Figure 5B and is a partial cross-sectional view of another embodiment of the chip placement groove 21 of the present invention; as shown in the figure, the main difference between the chip placement groove 21 of this embodiment and the previous embodiment lies in the form of the vent hole 210. The vent hole 210 of this embodiment is funnel-shaped. Its main purpose is that the gas pressure increases and the flow rate decreases at the outlet of the funnel-shaped vent hole 210, so it can provide a more uniform and smooth blowing effect and avoid excessive swinging during the floating positioning process of the chip C.

[0038] Please refer to Figure 6, which is the system architecture diagram of the second embodiment of the present invention; the main difference between the second embodiment and the foregoing first embodiment is that the second embodiment further includes a pressure sensing unit 5, which is electrically connected to the control unit 4 and is used to sense the gas pressure in the chip placement groove 21. In addition, the pneumatic switching valve 3 of this embodiment further includes a third inlet end 30, which is connected to the external atmospheric pressure P atm .

[0039] The operation method of the second embodiment is described in detail below. First, when the chip carrier 2 is in the first position P1 and the chip C is placed corresponding to the chip placement groove 21; then, the control unit 4 also first controls the pneumatic switching valve 3 to connect the vent hole 210 to the positive pressure source P Pos , to blow air to produce a floating positioning effect on the chip C. Furthermore, the control unit 4 also controls the pneumatic switching valve 3 to connect the vent hole 210 to the negative pressure source P Neg , so that the chip C is firmly fixed in the chip groove portion 211 of the chip placement groove 21. Then, the control unit 4 also controls the pneumatic switching valve 3 to connect the vent hole 210 to the external atmospheric pressure P atm , and moves the chip carrier 2 to the second position P2.

[0040] In other words, in the second embodiment, the chip C is positioned before being transferred, and negative pressure is not forcibly applied during the transfer process; accordingly, there is no need to separately provide positive pressure and negative pressure connecting pipelines or joints on the transfer path of the chip placement groove 211 and at the second position P2, making the overall device more streamlined and significantly reducing the assembly and maintenance costs.

[0041] In addition, a pressure sensing unit 5 is specially provided in the chip placement groove 21 of the second embodiment. When the control unit 4 controls the pneumatic switching valve 3 to connect the vent hole 210 to the negative pressure source P Neg , the control unit 4 simultaneously controls the pressure sensing unit 5 to detect the gas pressure in the chip placement groove 21, and through the judgment of the control unit 4, once the gas pressure is higher than the predetermined value, it means that the chip C is not completely placed in the chip groove portion 211 of the chip placement groove 21, so there is an air gap between the chip C and the chip placement groove 211, resulting in a large amount of air flowing into the chip placement groove 211, thereby increasing the inward gas pressure, indicating that the positioning is not completed. At this time, the control unit 4 will control the pneumatic switching valve 3 to connect the vent hole 210 to the positive pressure source P Pos again, that is, to perform floating positioning again; however, in other embodiments of the present invention, it is not limited to floating positioning again, and a warning message can also be sent through the control unit 4, such as a sound and light message or a warning message on the display screen.

[0042] In short, in the second embodiment of the present invention, when the chip C is adsorbed by negative pressure, the gas pressure in the chip placement groove 21 can be detected by the pressure sensing unit 5, and based on this, it can be determined whether the chip C has been positioned; because if the positioning is not completed, a large amount of air leakage will occur, resulting in an increase in the gas pressure in the chip placement groove 21, and the control unit 4 can issue a warning message or perform floating positioning again accordingly.

[0043] The above embodiments are only examples for convenience of description. The scope of the rights claimed by the present invention should be subject to the scope described in the claims, rather than being limited to the above embodiments.

[0044] Symbol Description

[0045] 2: Chip carrier

[0046] 3: Air pressure switching valve

[0047] 4: Control unit

[0048] 5: Pressure sensing unit

[0049] 20: Upper surface

[0050] 21: Chip placement groove

[0051] 30: Third inlet end

[0052] 31: First inlet end

[0053] 32: Second inlet end

[0054] 33: Outlet end

[0055] 210: Vent hole

[0056] 211: Chip groove part

[0057] 212: Air storage groove part

[0058] 213: Step part

[0059] C: Chip

[0060] D p : Pick-and-place device

[0061] P1: First position

[0062] P2: Second position

[0063] P atm : External atmospheric pressure

[0064] P Pos : Positive air pressure source

[0065] P Neg : Negative air pressure source

[0066] T h : Test head.

Claims

1. A chip transfer device with a floating positioning function transfers at least one chip from a first position to a second position. The chip transfer device includes: A chip carrier platform, whose upper surface includes at least one chip placement groove, and each chip placement groove is provided with at least one ventilation hole; A pneumatic switching valve, which includes a first inlet end, a second inlet end and an outlet end. The first inlet end is connected to a positive air pressure source, the second inlet end is connected to a negative air pressure source, and the outlet end is connected to the at least one ventilation hole of the chip carrier platform; And A control unit, which is electrically connected to the pneumatic switching valve and controls the pneumatic switching valve to connect the at least one ventilation hole to the positive air pressure source or the negative air pressure source; Wherein, when the at least one chip is placed in the at least one chip placement groove, the control unit controls the pneumatic switching valve to connect the at least one ventilation hole to the positive air pressure source, and the air flow flowing out of the positive air pressure source through the at least one ventilation hole blows towards the lower surface of the at least one chip, so that the at least one chip forms an air float; then the control unit controls the pneumatic switching valve to connect the at least one ventilation hole to the negative air pressure source.

2. The chip transfer device according to claim 1, wherein, When the at least one chip is placed in the at least one chip placement groove and the chip carrier platform is at the first position, the control unit first controls the pneumatic switching valve to connect the at least one ventilation hole to the positive air pressure source, and then the control unit controls the pneumatic switching valve to connect the at least one ventilation hole to the negative air pressure source and continues until the chip carrier platform moves to the second position.

3. The chip transfer device according to claim 1, wherein, The pneumatic switching valve further includes a third inlet end, which is connected to the external atmospheric pressure; when the at least one chip is placed in the at least one chip placement groove and the chip carrier platform is at the first position, the control unit controls the pneumatic switching valve to connect the at least one ventilation hole to the positive air pressure source, the negative air pressure source and the external atmospheric pressure in sequence, and then the chip carrier platform moves to the second position.

4. The chip transfer device as claimed in claim 1, further comprising a pressure sensing unit electrically connected to the control unit; wherein, When the control unit controls the pneumatic switching valve to connect at least one ventilation hole to the negative air pressure source, the control unit controls the pressure sensing unit to detect the gas pressure in the chip placement groove. Once the gas pressure is higher than a predetermined value, the control unit sends a warning message or controls the pneumatic switching valve to connect the at least one ventilation hole to the positive air pressure source again.

5. The chip transfer device according to claim 1, wherein, Each chip placement groove includes a chip groove part and an air storage groove part. The horizontal cross-sectional area of the air storage groove part is smaller than that of the chip groove part. The air storage groove part is located below the chip groove part, and the at least one ventilation hole is located at the bottom surface of the air storage groove part.

6. A chip floating positioning method includes: (A) Providing a chip to a chip placement groove on a chip carrier platform. The bottom surface of the chip placement groove is provided with at least one ventilation hole, and the at least one ventilation hole is connected to the outlet end of a pneumatic switching valve. The pneumatic switching valve further includes a first inlet end connected to a positive air pressure source and a second inlet end connected to a negative air pressure source; (B) The pneumatic switching valve is controlled to switch so that the at least one ventilation hole is connected to the positive air pressure source, and the air flow flowing out of the positive air pressure source through the at least one ventilation hole blows towards the lower surface of at least one chip, so that the at least one chip forms an air float; And (C) The air pressure switching valve is controlled to switch so that the at least one ventilation hole communicates with the negative air pressure source.

7. The chip floating positioning method according to claim 6, wherein, In steps (A) and (B), the chip carrier is located at the first position; in step (C), the air pressure switching valve continuously makes the at least one ventilation hole communicate with the negative air pressure source until the chip carrier moves to the second position.

8. The chip floating positioning method according to claim 6, wherein the air pressure switching valve further includes a third inlet end communicating with the external atmospheric pressure; in steps (A), (B), and (C), the chip carrier is located at the first position; after step (C), there is further a step (D), after the air pressure switching valve makes the at least one ventilation hole communicate with the external atmospheric pressure, the chip carrier moves to the second position.

9. The chip floating positioning method according to claim 7, wherein, In step (C), a pressure sensing unit is further provided to detect the gas pressure in the chip placement groove, and once the gas pressure is higher than a predetermined value, step (B) is repeated.

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