CN115047309A

CN115047309A - Automatic focusing and needle pressing method for probe station

Info

Publication number: CN115047309A
Application number: CN202210463088.5A
Authority: CN
Inventors: 李国强
Original assignee: Guangzhou Everbright Technology Co ltd
Current assignee: Guangzhou Everbright Technology Co ltd
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2022-09-13

Abstract

The invention discloses an automatic focusing and needle pressing method for a probe station, which comprises the following steps: receiving a signal that the image of the wafer is successfully identified and matched, and positioning the wafer; controlling the probe and a pressure sensing assembly which synchronously moves with the probe to perform needle pressing operation on the positioned wafer; when the probe is contacted with the surface of the wafer, a touch signal sent by the pressure sensing assembly is received, the probe is controlled to stop moving, and the operation of pressing the probe is completed. The invention can realize automatic identification and positioning and automatic needle pressing of the positioned wafer, improve the operation efficiency of the probe station and reduce the risk of scrapping products.

Description

Automatic focusing and needle pressing method for probe station

Technical Field

The invention relates to the technical field of probe stations, in particular to an automatic focusing and needle pressing method for a probe station.

Background

The probe station is mainly applied to the semiconductor industry and the photoelectric industry. Testing for integrated circuits and packages. The method is widely applied to the research and development of precise electrical measurement of complex and high-speed devices, and aims to ensure quality and reliability and reduce research and development time and cost of device manufacturing process. The process steps are crucial, the automation degree of the existing probe station can only automatically transfer the film, personnel manually search the pattern, the needle pressing is also manually performed, the automation degree is not high enough, and the production efficiency is low.

The probe station technology is to find out a test pattern on the surface of a wafer and confirm that a probe contacts a chip, so that the data is transmitted to a test instrument to test the whole wafer.

Most of probe stations in the current market manually find patterns, the probes are manually pressed, namely, a wafer stops after entering a machine station, the patterns to be tested are manually found, then the probes are manually descended little by using a knob, the force cannot be too large, the products can be punctured if the force is too large, the efficiency of the operation mode is low, and the risk of scrapping the products exists.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide an automatic focusing and needle pressing method for a probe station, which solves the technical problems of low operation efficiency and scrapped products of the existing probe station.

The purpose of the invention is realized by adopting the following technical scheme:

a probe station auto-focusing and needle pressing method comprises the following steps:

receiving a signal that the image of the wafer is successfully identified and matched, and positioning the wafer;

controlling the probe and a pressure sensing assembly which synchronously moves with the probe to perform needle pressing operation on the positioned wafer;

when the probe is contacted with the surface of the wafer, a touch signal sent by the pressure sensing assembly is received, the probe is controlled to stop moving, and the operation of pressing the probe is completed.

And further, controlling the linear driving device to drive the probe and the pressure sensing assembly which synchronously moves with the probe to perform probe pressing operation on the positioned wafer.

Further, the linear driving device comprises at least one baffle arranged on the probe station and a driving assembly arranged on the baffle and used for guiding the probe to move vertically and linearly.

Further, the driving assembly comprises a cross arm arranged on one side of the baffle, a sleeve which is rotatably inserted on the cross arm and is parallel to the moving direction of the probe, a screw rod which is inserted at the bottom of the sleeve in a threaded manner, a synchronous plate fixed at the bottom of the screw rod and a hanging rod arranged at the bottom of the synchronous plate;

one end of the probe, which is far away from the needle head of the probe, is arranged on the hanging rod;

one end of the synchronous plate is slidably clamped on the side wall of the baffle.

Furthermore, the driving assembly further comprises a first bevel gear arranged at the top of the sleeve, a second bevel gear which is rotatably inserted on the baffle and is matched with the first bevel gear, a stepping motor arranged on the baffle and a belt wheel arranged on an output shaft of the stepping motor, wherein a gear shaft of the second bevel gear is also provided with the belt wheel, and the two belt wheels are connected through a belt in a transmission manner.

Further, the pressure sensing assembly comprises a sensing needle head and two capacitors, the sensing needle head is provided with a vertical section and a horizontal section, the free end of the vertical section is flush with the needle head of the probe, the free end of the horizontal section extends between the two capacitors, and the horizontal section is rotatably connected to the suspender.

Further, the image of the wafer is identified and matched through an image sensor, and the image sensor comprises a CCD camera suspended above the probe station and a CCD lens installed on the CCD camera.

Furthermore, a working groove is formed in the probe station, a carrying disc for placing a vacuum chuck is arranged in the working groove, the vacuum chuck is used for carrying a wafer, a disc placing groove matched with the vacuum chuck is formed in the top of the carrying disc, and the carrying disc is connected with a displacement driving device;

the method for positioning the wafer comprises the following steps:

and controlling the displacement driving device to drive the carrying disc to move, and when receiving a signal that the image of the wafer is successfully identified and matched, controlling the displacement driving device to stop moving to realize the positioning of the wafer.

Furthermore, carry and be provided with two clamping jaws and action subassembly relatively on the dish, when vacuum chuck places carry on the dish, the action subassembly is used for guiding two the clamping jaw rotates in opposite directions, in order to with vacuum chuck presss from both sides the embrace.

Furthermore, a first through groove is horizontally arranged in the loading disc, two second through grooves vertically communicated with the first through groove are oppositely arranged on two sides of the top of the loading disc, a plate placing groove is formed in the bottom of the disc placing groove, and a third through groove is communicated between the bottom of the plate placing groove and the first through groove;

the action assembly comprises a pressing plate matched with the plate placing groove, a connecting rod which is inserted in the third through groove in a sliding mode, the top of the connecting rod is fixedly connected with the bottom of the pressing plate, a sliding ball arranged at the bottom of the connecting rod, inclined platforms which are oppositely arranged in the first through groove and are in sliding extrusion fit with the sliding ball, two fixed blocks which are respectively arranged on the two inclined platforms at the separated sides and are positioned in the first through groove, two racks which are respectively inserted on the two fixed blocks in a sliding mode, two transmission gears which are respectively arranged at the two ends of the first through groove, two first line wheels which are respectively coaxially arranged on the two transmission gears and are synchronous with the two transmission gears in motion, and second line wheels which are respectively and rotatably arranged at the notches at the tops of the two second through grooves;

a spring is sleeved on the outer side of the rack between the inclined table and the fixed block;

one end of each of the two clamping jaws is fixedly sleeved on the wheel shafts of the two second wire wheels;

two shaft slots are oppositely formed in the wall of the second through groove, two ends of a wheel shaft of the second wire wheel are rotatably inserted into the two shaft slots respectively, and a coil spring is arranged between the wheel shaft of the second wire wheel and the shaft slots;

a pull rope is wound on the second wire wheel, and the free end of the pull rope is bolted and fixed on the first wire wheel;

the elasticity value of the coil spring is smaller than that of the spring, when the spring is not deformed, the pressing plate protrudes to the outer side of the notch of the plate placing groove, the clamping jaw is in an unfolding state, and the coil spring is in an undeformed state.

Compared with the prior art, the invention has the beneficial effects that:

the invention can realize automatic identification and positioning and automatic needle pressing of the positioned wafer, improve the operation efficiency of the probe station and reduce the risk of scrapping products.

Drawings

FIG. 1 is a flow chart of a method for automatically focusing and pressing a probe station according to the present invention;

FIG. 2 is a schematic structural diagram of the automatic focusing and needle pressing method of the probe station of the present invention;

FIG. 3 is a schematic view of the structure of FIG. 2 from another state;

FIG. 4 is a schematic cross-sectional view of the vacuum chuck of FIGS. 2 and 3 mounted in a carrier plate;

FIG. 5 is a schematic cross-sectional view of the structure of the boat of FIG. 4 in another state;

FIG. 6 is a schematic diagram of electrical connections of the probe station auto-focusing and probe pressing method of the present invention.

In the figure: 10. a probe table 11 and a working groove;

20. a vacuum chuck;

30. an image sensor;

41. a sensing needle; 42. a capacitor;

50. a probe;

61. a cross arm; 62. a sleeve; 63. a screw; 64. a synchronization board; 65. a boom; 66. a first bevel gear; 67. a second taper tooth; 68. a pulley; 69. a stepping motor;

71. a carrying disc; 72. a disc placing groove; 73. a first bevel gear; 74. a second through groove; 75. placing the plate in a groove;

81. a clamping jaw; 82. pressing the plate; 83. a sliding bead; 84. a sloping table; 85. a fixed block; 86. a rack; 87. a transmission gear; 88. a first reel; 89. and a second wire wheel.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

1-6, a method for automatically focusing and pressing a probe station, comprising:

s1, the control component receives a signal that the image of the wafer is successfully identified and matched, and the wafer is positioned;

s2, controlling the probe and the pressure sensing component which synchronously moves with the probe by the control component to press the wafer after positioning;

s3, when the control component receives the contact pressure signal sent by the pressure sensing component when the probe contacts the surface of the wafer, the motion of the probe is controlled to stop, and the operation of pressing the needle is completed.

As a preferred implementation mode, the control component is a PLC or a single chip microcomputer.

In S1, a recognition image of the wafer is acquired by the image sensor 30, and the image sensor 30 includes a CCD camera suspended above the probe station 10 and a CCD lens mounted on the CCD camera. The CCD camera captures and recognizes images through the CCD lens, matches the same images preset by the program through data processing and obtaining, and if the capturing and matching are successful, controls the stepping motor 69 to start working. The CCD camera is characterized in that an optical image can be converted into a digital signal, the graph of the wafer is marked previously through program setting, and then the surface of the wafer is seen through the CCD lens to be identified and an image is captured.

In S2, the pressure sensing assembly is used to prevent the probe from pricking the wafer, and includes a sensing tip 41 and two capacitors 42, the sensing tip 41 has a vertical section (not shown) and a horizontal section (not shown), the free end of the vertical section is flush with the tip of the probe 50, and the free end of the horizontal section is located between the two capacitors 42. In this embodiment, the capacitor 42 may be mounted on the baffle plate by means of adhesive tape adhesion or by means of screws, and when the free end of the vertical section contacts the wafer, the generated reaction force may force the horizontal section to rotate obliquely, so that the free end of the horizontal section touches the capacitor 42 to generate a touch signal.

In S2, the control module controls the linear driving device to drive the probe and the pressure sensing module moving synchronously therewith to perform a stitch pressing operation on the positioned wafer. As a preferred embodiment, the linear driving means includes at least one blocking plate (not shown) provided on the probe station 10 and a driving assembly mounted on the blocking plate for guiding the probe 50 to move linearly in a vertical direction. The number of baffles in this embodiment is illustrated by two. The two baffles are respectively and symmetrically distributed on two sides of the vacuum chuck 20.

In a preferred embodiment, the driving assembly comprises a cross arm 61 disposed on the side of the baffle facing the vacuum chuck 20, a sleeve 62 rotatably inserted on the cross arm 61 and parallel to the moving direction of the probe 50, a screw 63 threadedly inserted at the bottom of the sleeve 62, a synchronizing plate 64 fixed at the bottom of the screw 63, and a suspension rod 65 disposed at the bottom of the synchronizing plate 64, wherein the end of the probe 50 away from the probe tip and the sensing tip 41 are mounted on the suspension rod 65. The horizontal section of the sensing needle 41 in the image sensor is rotatably connected to the suspension rod 65 through a pin shaft so as to facilitate the rotation of the suspension rod. When the sensing probe 41 does not contact the wafer, the horizontal section of the sensing probe 41 is always kept horizontal. When the sensing needle 41 contacts the wafer, the vertical section is acted by reverse and positive force to rotate the free end of the horizontal section downwards through the pin shaft. A touch signal, i.e., pressure feedback, is generated with the capacitance touching underneath, thereby stopping probe 50, indicating that probe 50 reaches the test point. The free end of the horizontal section is provided with a metal sheet matched with the capacitor, the capacitor 42 is touched through the metal sheet, the capacitor 42 transmits a stepping motor controller through a PLC signal, and then the stepping motor controller sends the stepping motor to stop working, and at the moment, the probe 50 just reaches the surface of the appointed wafer.

It is further preferred that one end of the synchronizing plate 64 is slidably engaged with the sidewall of the baffle. In this embodiment, the vertical spacing groove (not marking) of having seted up on the baffle, the slip joint has stopper (not marking) in the spacing groove, and synchronous board 64 end fixing can avoid synchronous board 64 to rotate when receiving sleeve 62, screw rod 63 drive on the stopper, makes screw rod 63 and synchronous board 64's moving direction keep in screw rod 63 axial. The screw 63 is extended from the sleeve 62 by the screw interaction between the guide sleeve 62 and the screw 63 by rotation of the guide sleeve 62, so as to move the synchronizing plate 64 in the axial direction of the screw 63,

further preferably, the driving assembly further includes a first bevel gear 66 disposed at the top of the sleeve 62, a second bevel gear 67 rotatably inserted into the baffle plate above the first bevel gear 66 and engaged with the first bevel gear 66, a stepping motor 69 mounted on the baffle plate, and a pulley 68 mounted on an output shaft of the stepping motor 69, wherein a pulley 68 is also disposed on a gear shaft of the second bevel gear 67, and the two pulleys 68 are connected by a belt transmission.

The stepping motor 69 of this embodiment has good control performance, and can be adjusted in a large range by changing the pulse frequency to achieve a rotation speed (or linear velocity) and can be rapidly started, braked and reversed, so that the probe 50 can more rapidly and accurately reach the designated range point, and the stepping motor 69 is electrically connected with the control assembly through the stepping motor controller. When the control assembly receives the touch signal, the control assembly sends a signal to the stepper motor controller, which then controls the stepper motor 69 to stop. After the image sensor 30 identifies and positions the wafer on the vacuum chuck 20, the control module controls the stepper motor 69 to start through the stepper motor controller, so as to push down the probe 50.

In S1, the probe pressing station 10 is provided with a working groove 11, the working groove 11 is provided with a carrying disc 71 for placing a vacuum chuck 20, the vacuum chuck is used for carrying a wafer, the top of the carrying disc 71 is provided with a disc placing groove 72 adapted to the vacuum chuck 20, the carrying disc 71 is connected with a displacement driving device, and the method for positioning the wafer includes:

and controlling the displacement driving device to drive the carrying disc to move, and controlling the displacement driving device to stop moving when receiving a signal that the image of the wafer is successfully identified and matched, so as to realize the positioning of the wafer.

The displacement driving device of this embodiment has at least one transmission direction for the carrying tray 71, and in this embodiment, the transmission direction of the displacement driving device is illustrated as X, Y, the displacement driving device may include corresponding tracks (not shown) in two directions of the X, Y axis and linear motors (not shown) corresponding to the respective guide rails, the bottom of the carrying tray 71 is fixed on the top of the corresponding track located above the corresponding track, the bottom of the track is installed on the top of the other guide rail, and the bottom of the working groove 11 is provided with a limit sliding groove for the other track to slide. The position of the carrier disc 71 in the axial direction X, Y can be adjusted by driving of each linear motor, so that the wafer on the vacuum chuck 20 can be moved to the image sensor for recognition.

In a preferred embodiment, two clamping jaws 81 and an actuating assembly are oppositely disposed on the carrier plate 71, and the actuating assembly is used for guiding the two clamping jaws 81 to rotate towards each other to clamp the vacuum chuck 20 when the vacuum chuck 20 is placed on the carrier plate 71.

Further preferably, a first through groove 73 is horizontally arranged in the carrying tray 71, two second through grooves 74 vertically communicated with the first through groove 73 are oppositely arranged on two sides of the top of the carrying tray 71, a plate placing groove 75 is arranged at the bottom of the tray placing groove 72, and a third through groove (not labeled) is communicated between the bottom of the plate placing groove 75 and the first through groove 73. The action component comprises a pressing plate 82 matched with the plate accommodating groove 75, a connecting rod (not marked) which is inserted in the third through groove in a sliding mode and the top of the connecting rod is fixedly connected with the bottom of the pressing plate 82, a sliding ball 83 arranged at the bottom of the connecting rod, inclined platforms 84 which are oppositely arranged in the first through groove 73 and are in sliding extrusion fit with the sliding ball 83, two fixing blocks 85 which are respectively arranged on the two inclined platforms 84 at the separated sides and are positioned in the first through groove 73, two racks 86 which are respectively inserted in the two fixing blocks 85 in a sliding mode, two transmission gears 87 which are respectively arranged at the two ends of the first through groove 73, two first line wheels 88 which are respectively coaxially arranged on the two transmission gears 87 and are synchronous with the two transmission gears 87 in motion, and second line wheels 89 which are respectively and rotatably arranged at the notches at the tops of the two second through grooves 74, and springs are sleeved on the outer sides of the racks 86 which are positioned between the inclined platforms 84 and the fixing blocks 85. One end of each clamping jaw 81 is fixedly sleeved on the wheel shaft of each second wire wheel 89.

Two shaft slots are oppositely arranged on the wall of the second through slot 74, two ends of the axle of the second wire wheel 89 are respectively inserted into the two shaft slots in a rotating way, and a coil spring is arranged between the axle of the second wire wheel 89 and the shaft slots. A pull rope is wound on the second wire wheel 89, and the free end of the pull rope is bolted and fixed on the first wire wheel 88. The spring force value of the coil spring is smaller than that of the spring.

When the spring is undeformed, the pressing plate 82 projects outside the notch of the plate accommodating groove 75, and the holding jaw 81 is in the deployed state. The coil spring is in an undeformed state.

In this embodiment, when the vacuum chuck 20 is placed in the tray placement groove 72 of the carrier tray 71, the pressing plate 82 is pressed into the tray placement groove 72, and the connecting rod and the sliding ball 83 are driven to move downward in the first through groove 73, so that the sliding ball 83 slides and extrudes the two ramps 84, the two ramps 84 are separated from each other, the two ramps 84 respectively drive the corresponding racks 86 to move away from each other, the two racks 86 respectively drive the two transmission gears 87 and the two first pulleys 88 to rotate, the two first pulleys 88 respectively drive the two second pulleys 89 to rotate through the pulling rope, so that the two second pulleys 89 respectively drive the two clamping jaws 81 to rotate toward each other, and the vacuum chuck 20 placed in the tray placement groove 72 is clamped and fixed. The design not only facilitates the taking and placing of the vacuum chuck 20 on the table body 10, but also automatically clamps and fixes the vacuum chuck 20 when the vacuum chuck 20 falls in the disc placing groove 72, so that the vacuum chuck 20 can be placed on the table body 10 more stably and reliably.

The above embodiments are only preferred embodiments of the present invention, and the scope of the present invention should not be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are intended to be covered by the claims.

Claims

1. A probe station automatic focusing and needle pressing method is characterized in that: the method comprises the following steps:

2. The probe station auto-focusing and needle pressing method of claim 1, wherein: and controlling the linear driving device to drive the probe and the pressure sensing assembly which synchronously moves with the probe to press the wafer after positioning.

3. The probe station auto-focusing and needle pressing method of claim 2, wherein: the linear driving device comprises at least one baffle arranged on the probe table and a driving assembly arranged on the baffle and used for guiding the probe to move vertically and linearly.

4. The probe station auto-focusing and needle pressing method of claim 3, wherein: the driving assembly comprises a cross arm arranged on one side of the baffle, a sleeve which is rotatably inserted on the cross arm and is parallel to the moving direction of the probe, a screw rod which is inserted at the bottom of the sleeve in a threaded manner, a synchronous plate fixed at the bottom of the screw rod and a hanging rod arranged at the bottom of the synchronous plate;

5. The probe station auto-focusing and needle pressing method of claim 4, wherein: the driving assembly further comprises a first bevel gear arranged at the top of the sleeve, a second bevel gear which is rotatably inserted into the baffle and is matched with the first bevel gear, a stepping motor arranged on the baffle and belt wheels arranged on an output shaft of the stepping motor, belt wheels are also arranged on a gear shaft of the second bevel gear, and the two belt wheels are connected through a belt in a transmission manner.

6. The probe station auto-focusing and needle pressing method of claim 4, wherein: the pressure sensing subassembly includes sensing syringe needle and two electric capacity, the sensing syringe needle has vertical section and horizontal segment, the free end of vertical section with the syringe needle of probe flushes mutually, the free end of horizontal segment extends two between the electric capacity, just the horizontal segment rotates to be connected on the jib.

7. The probe station auto-focusing and needle pressing method of claim 1, wherein: and identifying and matching the image of the wafer through an image sensor, wherein the image sensor comprises a CCD camera suspended above the probe station and a CCD lens installed on the CCD camera.

8. The probe station auto-focusing and needle pressing method of claim 1, wherein: a working groove is formed in the probe station, a carrying disc for placing a vacuum chuck is movably arranged in the working groove, the vacuum chuck is used for carrying a wafer, a disc placing groove matched with the vacuum chuck is formed in the top of the carrying disc, and the carrying disc is connected with a displacement driving device;

the method for positioning the wafer comprises the following steps:

9. The probe station auto-focusing and needle pressing method of claim 8, wherein: carry and be provided with two clamping jaws and action subassembly relatively on the dish, work as vacuum chuck places when carrying on the dish, action subassembly is used for guiding two the clamping jaw rotates in opposite directions, in order to incite somebody to action vacuum chuck presss from both sides and embraces.

10. The probe station auto-focusing and needle pressing method of claim 9, wherein: a first through groove is horizontally arranged in the loading disc, two second through grooves vertically communicated with the first through groove are oppositely formed in two sides of the top of the loading disc, a plate placing groove is formed in the bottom of the disc placing groove, and a third through groove is communicated between the bottom of the plate placing groove and the first through groove;

one ends of the two clamping jaws are respectively sleeved and fixed on wheel shafts of the two second wire wheels;