CN114390886A

CN114390886A - Micro device transfer method and device

Info

Publication number: CN114390886A
Application number: CN202111651933.3A
Authority: CN
Inventors: 邵志龙; 金小萍; 全大英
Original assignee: China Jiliang University Shangyu Advanced Research Institute Co Ltd
Current assignee: China Jiliang University Shangyu Advanced Research Institute Co Ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-22
Anticipated expiration: 2041-12-30
Also published as: CN114390886B

Abstract

The invention discloses a micro device transfer method and a device; the method breaks through the conventional way that the components are mounted from top to bottom by the SMT technology, and is mounted from bottom to top. Namely, the circuit board is placed face down, the micro device is placed on the tray in advance, the tray and the device on the tray are picked up by the mechanical arm of the SMT and moved to the position below the position to be pasted, the tray is lifted until the device on the tray is attached to the circuit board, and the process is repeated. Due to the adoption of a batch processing mode, the method and the device are particularly suitable for a transfer process in the production of huge micro devices such as miniLEDs or micro LED screens.

Description

Micro device transfer method and device

Technical Field

The invention belongs to the technical field of Surface Mount Technology (SMT), and particularly relates to a micro device transfer method and device.

Background

At present, a display screen has appeared, in which a backlight module is formed by arranging micro light emitting diode (MiniLED) devices, and one display screen adopts a plurality of backlight modules, and each backlight module can independently adjust the brightness, so that the display performance of the display screen is better. The smaller the size of the backlight LED of the display screen is, the better the display performance is, but the problem is that the time required for transferring the huge amount of MiniLED devices to the circuit board is greatly increased. Furthermore, the screen display performance will be further enhanced if each pixel of the display screen directly uses a smaller size light emitting diode (Micro-LED), in which case one screen will contain millions or even tens of millions of light emitting diodes (non-OLEDs). The speed bottlenecks that the prior art deals with such a huge number of transfer tasks limit the development of the industry.

Disclosure of Invention

The invention aims to provide a micro device transfer method and a micro device transfer device.

In a first aspect, the present invention provides a micro device transferring method, which comprises the following specific steps:

step one, the circuit board coated with the solder paste or the viscose is conveyed to a mounting area.

And step two, if the mounting surface of the circuit board is upward and enters the mounting area, the circuit board at the mounting area is clamped by the circuit board clamping and turning mechanism and turned over by 180 degrees.

And step three, the material moving module conveys the tray provided with the plurality of micro devices to the position right below the circuit board. The opening of the tray is arranged; the welding feet of the micro devices in the tray are all arranged upwards. The relative positions of all the micro devices in the tray correspond to the relative positions of all the device mounting points on the circuit board respectively.

And fourthly, the tray is lifted by the material moving module, so that each micro device in the tray is in contact with each device mounting point on the circuit board.

And step five, after all the micro devices in the tray are adhered to all the device mounting points on the circuit board, the material moving module drives the tray to descend, and the tray is separated from the chip.

And step six, finishing the device mounting by the circuit board and outputting a mounting area.

Preferably, after the step five is executed, whether the situation that no micro device is pasted on the device mounting point exists on the circuit board is checked, and if the situation exists, the material moving module grabs the single micro device and is pasted on the circuit board.

Preferably, in the fourth step, the upper supporting mechanism is used for abutting against the middle position of the circuit board from the upper part, so that the circuit board is kept stable.

Preferably, the bottom of the upper supporting mechanism is provided with a sucker.

In a second aspect, the present invention provides a micro device transfer apparatus, which includes a feeding module, a material transferring module, a conveying and overturning module, and a container. The conveying turnover module comprises a cross beam, a circuit board clamping turnover mechanism and a conveyor. The conveyer is used for conveying the circuit board to the mounting area. The crossbeam is fixed above the conveyor. The circuit board clamping and overturning mechanism comprises two clamping units arranged at intervals. The clamping unit comprises a circuit board groove-shaped clamp, a turnover shaft and a turnover shaft driving mechanism. The turnover shaft driving mechanism is arranged on the cross beam; the bottom end of the turnover shaft driving mechanism is provided with a turnover shaft. The axis of the turnover shaft is parallel to the conveying direction of the circuit board. The circuit board groove-shaped clamp is fixed at the end part of the turnover shaft. The turnover shaft driving mechanism can perform lifting motion under the driving of the power element; the turnover shaft driving mechanism can drive the turnover shaft to move along the conveying direction of the circuit board and rotate around the conveying direction of the circuit board. The material moving module is used for conveying the single micro device or the tray provided with the plurality of micro devices output by the material supply module to the mounting area and mounting the micro device or the tray on the mounting surface of the circuit board.

Preferably, the conveyor is provided with two conveying belts at intervals. The two conveying belts are respectively used for supporting and conveying two sides of the circuit board.

Preferably, the conveying turnover module further comprises an upper supporting mechanism. The upper supporting mechanism is arranged below the cross beam and is positioned between the two clamping units. Go up supporting mechanism and include vertical connecting pipe, first sucking disc, spacing pole head and flexible negative pressure pipe. The vertical connecting pipe is connected to the cross beam in a sliding mode and driven by a power element to lift. The bottom end of the vertical connecting pipe is coaxially provided with a first sucker and a limiting rod head; the limiting rod head is positioned in the first sucking disc and used for limiting the first sucking disc. The first suction disc is connected to an external vacuum source through a negative pressure pipe.

Preferably, a limit sensor is installed at the bottom end of the limit rod head.

Preferably, the material moving module comprises a pair of X-axis guide rails, an X-axis sliding block, a Y-axis guide rail, a Y-axis sliding block, a second sucking disc and a suction nozzle which are arranged in parallel; two parallel X-axis guide rails are fixed on the frame. The two X-axis sliding blocks are respectively connected with the two X-axis guide rails in a sliding manner and driven by a power element to slide. The Y-axis guide rail is arranged between the two X-axis sliding blocks. The Y-axis sliding block is installed on the Y-axis guide rail and can slide along the axis direction of the Y-axis guide rail and rotate around the axis direction of the Y-axis guide rail. The sliding and the rotation of the Y-axis sliding block are driven by a power element. The second sucking disc and the suction nozzle are both arranged on the Y-axis sliding block and can perform telescopic motion relative to the Y-axis sliding block (9) under the driving of the power element. The second sucking disc and the suction nozzle are respectively used for sucking the tray and a single micro period; the second suction cup and the suction nozzle are both connected to a vacuum source.

Preferably, the feeding module comprises a first feeder and a second feeder; the first feeder is used for outputting a tray which is provided with micro devices and has an upward opening. The second feeder is used for outputting a single micro device.

Preferably, a container is arranged below the conveying turnover module and used for collecting empty trays.

The invention has the following beneficial effects:

1. the invention improves the transfer speed of a huge number of micro devices, and particularly solves the industrial problem of too low transfer speed in the process of producing miniLED screens or micro LED screens.

2. The invention changes the working mode that one suction nozzle of the traditional SMT chip mounter only picks up one device at a time, improves the transfer speed of a huge amount of micro devices, reduces the energy consumption of each unit of transfer amount, and accords with the great trend of energy conservation and emission reduction.

Drawings

Fig. 1 is a flow chart of a micro device transfer method.

Fig. 2 is a schematic structural diagram of an SMT pick & place machine using the transfer method.

Detailed Description

The micro device transfer method is further described with reference to the drawings and the embodiments.

Example 1

As shown in fig. 1 and 2, a micro device transfer apparatus includes a supply module, a transfer module, a second feeder 14, a conveying turn-over module, and a container 15. Fig. 2 is a schematic diagram of a chip mounter employing the transfer method, and for simplification of description, conventional parts such as a frame and a negative pressure mechanism in the basic structure of the chip mounter are not shown, and the parts are marked mainly as an innovation point and an auxiliary description device of the present invention. In fig. 2, portions indicated by reference numerals 1 to 5 are conveying turn-over modules; the parts indicated by reference numerals 6 to 11 are material moving modules; the parts indicated by

reference numerals

12 and 13 are feed modules; reference numeral 14 denotes a second feeder.

As shown in fig. 2, the conveying turnover module includes a beam 1, an upper support mechanism 2, a circuit board clamping and turning mechanism 3, and a conveyor 4. The conveyor 4 is arranged on the frame; two conveyer belts are arranged on the conveyer 4 at intervals. The two conveying belts are respectively used for supporting and conveying two sides of the circuit board.

Two ends of a cross beam 1 positioned on the top of the conveyor 4 are fixed on the frame, and circuit board clamping and overturning mechanisms 3 arranged in pairs are arranged below the two ends of the cross beam. The circuit board clamping and overturning mechanism 3 comprises two clamping units arranged at intervals. The clamping unit comprises a circuit board groove-shaped clamp 3-1, a turnover shaft 3-2 and a turnover shaft driving mechanism 3-3. The turnover shaft driving mechanism 3-3 is arranged on the cross beam; the bottom end of the turnover shaft driving mechanism 3-3 is provided with a turnover shaft 3-2. The axis of the turnover shaft 3-2 is parallel to the conveying direction of the circuit board. A circuit board groove-shaped clamp 3-1 is fixed at the end part of the turnover shaft 3-2. The turnover shaft driving mechanism 3-3 can perform lifting motion under the driving of a power element; the turnover shaft driving mechanism 3-3 can drive the turnover shaft 3-2 to move along the conveying direction of the circuit board and rotate around the conveying axis of the circuit board.

Under the action of the turnover shaft driving mechanism 3-3, the clamp 3-1 can perform transverse movement, lifting movement and turnover movement, so that the clamp 3-1 can adapt to circuit boards of different sizes, and a space can be made for conveying the circuit boards by lifting. The lifting motion of the turnover shaft driving mechanism 3-3 and the transverse movement of the turnover shaft 3-2 are realized by an electric push rod; the rotation of the turning shaft is realized by a motor.

The upper supporting mechanism 2 is installed below the cross beam and located between the two clamping units. The upper supporting mechanism 2 comprises a vertical connecting pipe, a first sucker 2-1, a limiting rod head 2-2 and a flexible negative pressure pipe 2-3. The vertical connecting pipe is connected to the cross beam in a sliding mode and driven by a power element to lift. The bottom end of the vertical connecting pipe is coaxially provided with a first sucker 2-1 and a limiting rod head 2-2; the limiting rod head 2-2 is positioned in the first sucking disc 2-1 and used for limiting the first sucking disc 2-1 and avoiding the first sucking disc 2-1 from excessively extruding the circuit board. The first suction cup 2-1 is connected to an external vacuum source through a negative pressure tube 2-3. The inner side of the limiting rod head 2-2 is connected with the outer side of the flexible negative pressure pipe 2-3 in a sealing mode, and the end face of the limiting rod head is not flat, so that a gas medium can flow conveniently. When the upper surface of the circuit board is contacted with the first sucker 2-1, the circuit board 5 can be supported from the upper part by the negative pressure in the negative pressure pipe 2-3 and the limiting rod head. Therefore, the upper supporting mechanism can eliminate or weaken the warping of the large circuit board, and therefore the pasting success rate is improved.

The material moving module comprises a pair of X-axis guide rails 6, a pair of X-axis sliding blocks 7, a Y-axis guide rail 8, a Y-axis sliding block 9, a second suction cup 10 and a suction nozzle 11 which are arranged in parallel; two parallel X-axis guide rails 6 are fixed on the frame. The two X-axis sliding blocks 7 are respectively connected with the two X-axis guide rails 6 in a sliding mode and driven by a power element to slide. The Y-axis guide rail 8 is installed between the two X-axis sliders 7. The Y-axis slider 9 is mounted on the Y-axis guide rail 8, and can slide in the axial direction of the Y-axis guide rail 8 and rotate around the axial direction of the Y-axis guide rail 8. The sliding and rotating of the Y-axis slide block 9 are driven by a power element. The second suction cup 10 and the suction nozzle 11 are both mounted on the Y-axis slider 9, and both can be driven by a power element in the Y-axis slider to move along the respective axial directions. The suction nozzle 11 can suck the single micro device output by the second feeder 14; the second suction cup 10 and the suction nozzle 11 are both connected to a vacuum source through an air tube.

The rotation range of the Y-axis sliding block is not less than 90 degrees; the power elements for driving and their corresponding transmission mechanisms are not shown. The driving mechanism not shown can be composed of a conventional motor, a reduction gear, a rack or a screw, which is not the innovation point of the invention, and is not described in detail.

The feeder module comprises a first feeder 12; the first feeder 12 is used to continuously output trays on which micro devices are arrayed and which have an upward opening at the take-out frame 13. The first feeder 12 continuously supplies the transport overturning module with trays containing the devices, which are transported together with the trays onto the extracting rack 13. The second feeder 14 is used for the transfer module to provide a single device. A container 15 is mounted below the transport turnover module for collecting empty trays.

As shown in fig. 1, the transferring method of the micro device transferring apparatus is as follows:

s1) is moved into the wiring board with the device mounting surface facing down. Conveying the circuit board coated with the soldering paste or the viscose to a mounting area; the mounting area is positioned right below the upper supporting mechanism 2; the circuit board clamping and overturning mechanism 3 and the upper supporting mechanism 2 move to the position of the conveyor 4 at the moment, and a space is made for the circuit board to enter the mounting area. After the circuit board groove-shaped clamps 3-1 of the two clamping units descend to the two sides of the circuit board, the circuit board groove-shaped clamps move relatively, so that the circuit board is clamped by the two circuit board groove-shaped clamps 3-1.

The circuit board is turned over to the surface to be mounted downwards, and the specific process is as follows: the two clamping units drive the circuit board to rise, and then the two clamping units drive the circuit board groove-shaped clamp 3-1 to turn over 180 degrees, so that the surface of the circuit board faces downwards; then, the upper support mechanism 2 is lowered, so that the position restricting rod head 2-2 is brought into contact with the circuit board. If the device mounting surface is facing downward before the circuit board is moved in, the circuit board does not need to be turned over.

S2) the material moving module picks up the device. The transfer module picks the tray of devices from the picking rack 13 of the first feeder 12 (and should pick from below the tray together with the devices on the tray) and may also pick a single device from the second feeder 14.

S3) the material transfer module moves the picked-up device to below the mounting surface of the circuit board. During this movement of the transfer module, if the device is placed on a tray, the transfer module should adjust the moving speed and the inclination angle of the second suction cup 10 to prevent the device from falling off during the movement. If a single component is picked up, the suction nozzle 11 needs to be adjusted from the tilt angle at the time of pickup to a vertical upward direction.

S4) moving the material moving module upwards and mounting the device. If the device to be mounted is placed on the tray, the Y-axis slider (mounting head) 9 adjusts the direction of the tray to be parallel to the circuit board, and drives the second suction cup 10 to ascend and mount. If a single device is required to be mounted at this time, the Y-axis slide block 9 should drive the suction nozzle 11 to ascend until the device is attached to the corresponding position of the circuit board.

S5) if the tray-loading device is picked up by the material moving module for the last time, moving the empty tray to a recovery position, and if not, entering S6. When empty trays are placed, the material moving module can enable the trays to fall into the recovery container 15 by self by utilizing the inertia of the trays so as to reduce the movement overhead of the material moving module.

S6), judging whether the transfer task of the current circuit board is completed, if not, returning to the step S2), and if so, moving the circuit board out. Before the removal, whether the circuit board is turned to be the device upward or not can be determined according to the requirements of the subsequent process. The sequence of the turning steps after the completion of the mounting of the board and before the removal is the reverse of that in S1.

S7), the whole transfer task is determined whether to be completed, if not, the first step is returned to, and if so, the transfer task is ended.

According to the method, if the micro devices are arranged on the tray in advance according to the mounting requirements of the circuit board, the working efficiency of the material moving module (manipulator) can be improved by m times and n times, wherein m and n are respectively the number of rows and columns of the micro devices arranged on the tray. The main purpose of picking up a single device for mounting is leakage repairing. The chip mounter implementing the transfer method has higher requirement on the movement speed of the material transfer module, and the chip mounter has low requirement on the movement speed, so that the equipment cost of the transfer process can be reduced.

Claims

1. A micro device transfer method, comprising the steps of:

step one, conveying the circuit board coated with soldering paste or viscose to a mounting area;

step two, if the mounting surface of the circuit board is upward and enters a mounting area, the circuit board at the mounting area clamps and turns the circuit board by 180 degrees by the circuit board clamping and turning mechanism;

thirdly, the material moving module conveys the tray provided with the plurality of micro devices to the position right below the circuit board; the opening of the tray is arranged; the bonding pads of the micro devices in the tray are all arranged upwards; the relative positions of all the micro devices in the tray correspond to the relative positions of all the device mounting points on the circuit board respectively;

lifting the tray by the material moving module to enable each micro device in the tray to be in contact with each device mounting point on the circuit board;

step five, after all the micro devices in the tray are adhered to the mounting points of all the devices on the circuit board, the material moving module drives the tray to descend, and the tray is separated from the micro devices;

2. The micro device transfer method according to claim 1, wherein: and after the step five is executed, checking whether the situation that no micro device is adhered to the device installation point exists on the circuit board, and if so, grabbing the single micro device by the material moving module and attaching the single micro device to the circuit board.

3. The micro device transfer method according to claim 1, wherein: in the fourth step, the upper supporting mechanism supports against the middle position of the circuit board from the upper part, so that the circuit board is kept stable.

4. A micro device transfer method according to claim 3, wherein: and the bottom of the upper supporting mechanism is provided with a sucker.

5. The utility model provides a micro device transfer device, includes the feed module, moves the material module and carries turn-over module, its characterized in that: the conveying turnover module comprises a cross beam (1), a circuit board clamping turnover mechanism (3) and a conveyor (4); the conveyor (4) is used for inputting or outputting the circuit board to the mounting area; the cross beam is fixed above the conveyor (4); the circuit board clamping and overturning mechanism (3) comprises two clamping units which are arranged at intervals; the clamping unit comprises a circuit board groove-shaped clamp (3-1), a turnover shaft (3-2) and a turnover shaft driving mechanism (3-3); the turnover shaft driving mechanism (3-3) is arranged on the cross beam; the bottom end of the turnover shaft driving mechanism (3-3) is provided with a turnover shaft (3-2); the axis of the turnover shaft (3-2) is parallel to the conveying direction of the circuit board; a circuit board groove-shaped clamp (3-1) is fixed at the end part of the turnover shaft (3-2); the turnover shaft driving mechanism (3-3) can perform lifting motion under the driving of a power element; the turnover shaft driving mechanism (3-3) can drive the turnover shaft (3-2) to move along the conveying direction of the circuit board and rotate around the conveying direction of the circuit board; the material moving module is used for conveying the single micro device or the tray provided with the plurality of micro devices output by the material supply module to the mounting area and mounting the micro device or the tray on the mounting surface of the circuit board.

6. The micro device transfer apparatus according to claim 5, wherein: two conveying belts are arranged on the conveyor (4) at intervals; the two conveyer belts are respectively used for supporting two sides of the circuit board and conveying the circuit board.

7. The micro device transfer apparatus according to claim 5, wherein: the conveying turnover module also comprises an upper supporting mechanism (2); the upper supporting mechanism (2) is arranged below the cross beam and is positioned between the two clamping units; the upper supporting mechanism (2) comprises a vertical connecting pipe, a first sucker (2-1), a limiting rod head (2-2) and a flexible negative pressure pipe (2-3); the vertical connecting pipe is connected to the cross beam in a sliding manner and is driven by the power element to lift; the bottom end of the vertical connecting pipe is coaxially provided with a first sucker (2-1) and a limiting rod head (2-2); the limiting rod head (2-2) is positioned in the first sucking disc (2-1) and used for limiting the first sucking disc (2-1); the first suction cup (2-1) is connected to an external vacuum source through a negative pressure pipe (2-3).

8. The micro device transfer apparatus according to claim 7, wherein: and a limiting sensor is arranged at the bottom end of the limiting rod head (2-2).

9. The micro device transfer apparatus according to claim 5, wherein: the material moving module comprises a pair of X-axis guide rails (6), an X-axis sliding block (7), a Y-axis guide rail (8), a Y-axis sliding block (9), a second sucking disc (10) and a sucking nozzle (11) which are arranged in parallel; two parallel X-axis guide rails (6) are fixed on the frame; the two X-axis sliding blocks (7) are respectively connected with the two X-axis guide rails (6) in a sliding manner and driven by a power element to slide; the Y-axis guide rail (8) is arranged between the two X-axis sliding blocks (7); the Y-axis sliding block (9) is installed on the Y-axis guide rail (8) and can slide along the axial direction of the Y-axis guide rail (8) and rotate around the axial direction of the Y-axis guide rail (8); the sliding and the rotation of the Y-axis sliding block (9) are driven by a power element; the second suction cup (10) and the suction nozzle (11) are both arranged on the Y-axis sliding block (9) and can perform telescopic motion relative to the Y-axis sliding block (9) under the driving of a power element; the second sucking disc (10) and the suction nozzle (11) are respectively used for sucking the tray and a single micro device; the second suction cup (10) and the suction nozzle (11) are both connected to a vacuum source; and a container (15) is arranged below the conveying turnover module and used for collecting empty trays.

10. The micro device transfer apparatus according to claim 5, wherein: the supply module comprises a first supply (12) and a second supply (14); a first feeder (12) for outputting trays containing micro devices and having an upward opening; the second feeder (14) is used for outputting a single micro device.