WO2022000204A1

WO2022000204A1 - Transfer head and manufacturing method therefor, chip transfer system, and chip transfer method

Info

Publication number: WO2022000204A1
Application number: PCT/CN2020/099029
Authority: WO
Inventors: 翟峰; 唐彪
Original assignee: 重庆康佳光电技术研究院有限公司
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2022-01-06

Abstract

The present invention relates to a transfer head and a manufacturing method therefor, a chip transfer system, and a chip transfer method. The transfer head is provided with pipelines, such that a micro flip LED chip and solder respectively directly flow out from a first pipeline and a second pipeline and through a third pipeline in the form of droplets, and fall into corresponding chip welding areas.

Description

Transfer head and manufacturing method thereof, chip transfer system and chip transfer method

technical field

The present invention relates to the field of semiconductor devices, and in particular, to a transfer head and a manufacturing method thereof, a chip transfer system and a chip transfer method.

Background technique

Micro Light Emitting Diode (Micro-LED) display technology has the advantages of high brightness, high response speed, low power consumption, long life, etc., and has become a research hotspot in pursuit of a new generation of display technology. In the process of manufacturing large and medium-sized Micro-LED displays, mass transfer of micro-LED chips and LED chip bonding processes are required. Therefore, a key technology facing micro-LED is to transfer micro-LED chips to the display backplane through mass transfer. In the related art, generally, a releasable adhesive layer is provided on the first temporary substrate, and the micro-LED chip is transferred from the growth substrate to the first temporary substrate through the adhesive layer, and then the micro-LED chip is transferred from the growth substrate to the first temporary substrate. The second temporary substrate transfers the micro-LED chips from the first temporary substrate to the display backplane. Such a chip transfer process is relatively complicated, and the transfer efficiency is low.

Therefore, how to realize the convenient and efficient transfer of micro-flip-chip LED chips is an urgent problem to be solved.

technical problem

In view of the above-mentioned deficiencies of the related art, the purpose of the present application is to provide a transfer head and a manufacturing method thereof, a chip transfer system and a chip transfer method, in order to solve the problem that the transfer process of the miniature flip-chip LED chip in the related art is complicated and low in efficiency The problem.

technical solutions

A transfer head comprising:

Transfer head body;

at least one transfer unit formed on the transfer head body;

The transfer unit includes a first pipeline, a second pipeline and a third pipeline located in the main body of the transfer head, the first ports of the first pipeline and the second pipeline are respectively located on the first surface of the transfer head, the first pipeline and the second pipeline The two ports are respectively located in the transfer head body, and are respectively communicated with the first port of the third pipeline, and the second port of the third pipeline is located on the second surface of the transfer head;

The first port of the first pipe is for the inflow of chip droplets wrapped with the micro-flip-chip LED chip, and flows into the third pipe through its second port; the first port of the second pipe is for the inflow of solder droplets, through its second port into the third pipe; the chip drips and solder drips flowing into the third pipe flow out through the second port of the third pipe.

When the structure of the above-mentioned transfer head is applied to the transfer of the micro-flip-chip LED chip, the micro-flip-chip LED chip and the solder can be directly transferred from the first pipe and the second pipe on the transfer head through the third pipe directly in the form of drops. The flow falls on the corresponding die bonding area (ie, the die bonding area), and the traditional transfer process using the first temporary substrate and the second temporary substrate is no longer required, which can simplify the transfer steps of the micro-flip-chip LED chip and improve the micro-flip chip. The convenience and transfer efficiency of LED chip transfer; at the same time, a new transfer method of micro flip-chip LED chip is provided.

Based on the same inventive concept, the present application also provides a method for making the above-mentioned transfer head, including:

forming a first substrate layer;

forming a photoresist layer on the first substrate layer;

After the photoresist is exposed and developed according to the pipeline distribution diagram, a photoresist layer is left in the corresponding areas where the first pipeline, the second pipeline and the third pipeline are arranged;

A second substrate layer covering the entire photoresist layer is provided on the first substrate layer;

After the photoresist layer is washed away with the target solution, the space originally occupied by the photoresist layer constitutes the first conduit, the second conduit and the third conduit.

The manufacturing method of the above-mentioned transfer head is simple, fast, and low-cost, and the above-mentioned transfer head can be produced and used quickly and at low cost, which is beneficial to popularization.

Based on the same inventive concept, the present application also provides a chip transfer system, which is characterized in that it includes a first container, a second container, a microfluidic control device, a connecting tube, and the transfer head shown above;

The first container is used to hold the solution mixed with the micro-flip-chip LED chips, and the micro-flip-chip LED chips are suspended in the solution, and the second container is used to hold the solder solution;

The first feed port and the second feed port of the micro-flow control device are respectively connected to the liquid outlets of the first container and the second container through connecting pipes, and the first and second feed ports of the level flow control device are respectively The first port of the first pipe and the second pipe are connected, and the second port of the third pipe is aligned with the chip bonding area on the circuit board for soldering the miniature flip-chip LED chip; the bit flow control device controls the solder solution in the second container Solder droplets are formed and flow into the second pipe, and flow out to the chip bonding area through the second port of the third pipe, and control the solution mixed with the micro-flip-chip LED chips in the first container to form chip droplets through the connecting pipe. The first pipe flows out through the second port of the third pipe and falls to the die bonding area.

The above chip transfer system realizes a new transfer process of micro-flip-chip LED chips. Compared with the traditional transfer process using the first temporary substrate and the second temporary substrate, the transfer steps of micro-flip-chip LED chips can be simplified and the micro-flip-chip transfer process can be improved. The convenience and transfer efficiency of LED chip transfer.

Based on the same inventive concept, the present application also provides a chip transfer method using the chip transfer system shown above, including:

The solder solution in the second container is controlled by the microfluidic control device to form solder droplets, which flow into the second pipe, and flow out to the chip bonding area through the second port of the third pipe, and control the packaged micro-flip in the first container. The solution of the LED chip forms the chip droplet and flows into the first pipe through the connecting pipe, and flows out to the chip bonding area through the second port of the third pipe;

The liquid solder in the die bonding area is cured to bond the chip to the die bonding area.

beneficial effect

Since the chip transfer system shown above is used to transfer the micro-flip-chip LED chips, the transfer process of the first temporary substrate and the second temporary substrate is no longer used, which can simplify the transfer steps of the micro-flip-chip LED chip and improve the micro-flip-chip LED chip. The convenience and transfer efficiency of chip transfer make the production of display panels more convenient and efficient, thereby shortening the system cycle of display versions to a certain extent and reducing the production costs of display panels.

Description of drawings

Figure 1-1 is a schematic diagram of the structure of the transfer head provided by the present invention 1;

Figure 1-2 is a schematic diagram 2 of the structure of the transfer head provided by the present invention;

FIG. 2 is a schematic diagram three of the structure of the transfer head provided by the present invention;

Figure 3-1 is a schematic diagram 4 of the structure of the transfer head provided by the present invention;

Figure 3-2 is a schematic diagram 5 of the structure of the transfer head provided by the present invention;

Fig. 3-3 is a schematic diagram 6 of the structure of the transfer head provided by the present invention;

3-4 are schematic diagrams of the structure of the transfer head provided by the present invention VII;

3-5 are schematic diagrams of the eighth structure of the transfer head provided by the present invention;

3-6 are schematic diagrams 9 of the structure of the transfer head provided by the present invention;

Fig. 4-1 is a schematic structural diagram ten of the transfer head provided by the present invention;

Figure 4-2 is a schematic diagram eleventh of the structure of the transfer head provided by the present invention;

4-3 is a schematic diagram twelve of the structure of the transfer head provided by the present invention;

4-4 are schematic diagrams of the structure of the transfer head provided by the present invention thirteen;

Figure 5-1 is a schematic diagram of the structure of the transfer head provided by the present invention thirteen;

Figure 5-2 is a schematic diagram of the connection of the transfer head shown in Figure 5-1;

6-1 is a schematic flowchart of a method for manufacturing a transfer head provided by an optional embodiment of the present invention;

Figure 6-2 is a schematic diagram of the process corresponding to the method of making the transfer head in Figure 6-1;

6-3 is a schematic structural diagram of a manufactured transfer head provided by an optional embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a chip transfer system provided by another optional embodiment of the present invention;

FIG. 8 provides a schematic diagram of the movement of the transfer head according to another optional embodiment of the present invention;

Description of reference numbers:

1-transfer head body, 11, 611- top surface, 12, 612 bottom surface, 13- first side, 14- second side, 2, 631- first pipe, 21, 6311, 741- first pipe of first pipe Ports, 22, 6312 - The second port of the first pipe, 3, 632 - The second pipe, 31, 6321, 742 - The first port of the second pipe, 32, 6322 - The second port of the second pipe, 4, 633 - the third pipe, 41, 6331 - the first port of the third pipe, 42, 6332 - the second port of the third pipe, 5 - the connecting pipe for transferring the chip drip 5, 6 - the connecting pipe for transferring the solder drip , 61-first substrate layer, 62-photoresist layer, 63-pipeline, 64-mask, 71-first container, 72-second container, 73-microfluidic control device, 74-transfer head, 75 -connecting pipe, 731-first through the feed port, 732-second feed port, 733-first discharge port, 734-second discharge port, 76-circuit board, 761-chip bonding area, 77- The form after the droplets converge.

Embodiments of the present invention

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the accompanying drawings. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of this application is provided.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application.

In the related art, the transfer process of the micro flip-chip LED chip is relatively complicated and has low efficiency.

Based on this, the present application hopes to provide a solution that can solve the above technical problems, the details of which will be described in the subsequent embodiments.

A transfer head provided by this embodiment includes:

The transfer head body; in this embodiment, the shape (for example, it can be a hexahedron, a pie or a sphere, etc.) and the material of the transfer head body are not limited;

It also includes at least one transfer unit formed on the transfer head body; wherein, the number of the transfer units can be flexibly set according to specific application scenarios. For example, for the application scenario of single-chip transfer, only one transfer unit may be formed on the transfer head body, and for the application scenario of single multi-chip transfer, multiple transfer units may be formed on the transfer head body.

In this embodiment, for each transfer unit, it includes but is not limited to the first pipeline, the second pipeline and the third pipeline located in the transfer head body, the first port of the first pipeline and the second pipeline (that is, the first pipeline). The feed ports of a pipeline and a second pipeline) are located on the first and second surfaces of the transfer head respectively (that is, the first port is exposed outside the transfer head body for external access), the first pipeline and the second The second port of the second pipe (that is, the outlet of the first pipe and the second pipe) is located in the transfer head body respectively, and is connected with the first port of the third pipe (the first port is also located in the transfer head body) are connected separately, and the second port of the third pipe is located on the third surface of the transfer head (that is, the second port is also exposed outside the transfer head body), so that the chips wrapped with the micro flip-chip LED chips can drip from the first The first port of the pipe flows into the first pipe, and flows into the third pipe through the second port of the first pipe, and the solder droplets can flow from the first port of the second pipe into the second pipe, and pass through the second pipe. The second port flows into the third pipe, and the chip drips and solder drips that flow into the third pipe flow out through the second port of the third pipe. Therefore, when the second port of the third pipe is aligned with the chip bonding area (ie the die bonding area), the chip droplets and solder droplets flowing into the third pipe can flow directly through the second port of the third pipe and fall to the chip on the welding area.

The chip droplet in this embodiment refers to a droplet wrapped with a micro-flip-chip LED chip. Of course, the micro-flip-chip LED chip can also be replaced with other micro-devices as required.

It should be understood that, based on the transfer head with the above structure, the specific positions of the transfer units provided on the transfer head, as well as the positional distribution and shape of the first pipeline, the second pipeline and the third pipeline of each transfer unit can also be Flexible settings according to specific application needs. For ease of understanding, this embodiment is hereinafter combined with some setting examples for ease of understanding.

In some examples of this embodiment, the first ports of the first pipe and the second pipe, and the second port of the third pipe may be arranged on the same surface of the transfer head body, that is, the first surface and the second surface. And the third side is the same side of the transfer head body. For example, see Figure 1-1 and Figure 1-2.

In Figure 1-1, the transfer head body 1 is provided with a first pipe 2, a second pipe 3 and a third pipe 4, wherein the combined shape of the first pipe 2, the second pipe 3 and the third pipe 4 is similar to " "mountain". The first port 21 of the first pipe 2, the first port 31 of the second pipe 3 and the second port 42 of the third pipe 4 are located on the same surface of the transfer head body 1, the second port 22 of the first pipe 2, the second port 42 of the third pipe 4 The second port 32 of the second pipe 3 is located inside the transfer head body 1 and communicates with the first port 42 of the third pipe 4 .

Compared with the first pipe 2 , the second pipe 3 and the third pipe 4 in FIG. 1-2 and FIG. 1-1 , the main difference lies in the combined shape of the first pipe 2 , the second pipe 3 and the third pipe 4 resembling an arrow.

However, it should be understood that when the first pipe, the first port of the second pipe, and the second port of the third pipe are arranged on the same surface of the transfer head body, the first pipe, the second pipe and the third pipe are in the transfer process. The distribution inside the head body is not limited to those shown in the above two figures. It can be flexibly set according to needs.

In some examples of this embodiment, the first ports of the first pipeline and the second pipeline may be located on the same surface, that is, the first surface and the second surface are the same surface of the transfer head body (for example, referred to as the top face), the second port of the third pipe can be arranged on a face different from the front face. See Figure 2 for an example.

In FIG. 2 , a first pipe 2 , a second pipe 3 and a third pipe 4 are arranged in the transfer head body 1 , wherein the combined shape of the first pipe 2 , the second pipe 3 and the third pipe 4 is "Y" shape. The first port 21 of the first pipe 2 and the first port 31 of the second pipe 3 are located on the top surface 11 of the transfer head body 1 , the second port 22 of the first pipe 2 and the second port 32 of the second pipe 3 are located on the top surface 11 of the transfer head body 1 . The inside of the transfer head body 1 communicates with the first port 42 of the third pipe 4 ; the second port 42 of the third pipe 4 is located on the bottom surface 12 of the transfer head body 1 (ie, the side opposite to the top surface 11 ).

For another example, in other setting examples, please refer to FIG. 3-1 , the difference from FIG. 2 is mainly that when the first ports of the first pipe 2 and the second pipe 3 extend to the top surface 11 , the The shape is slightly different. Please refer to Fig. 3-2. The main difference from Fig. 2 is that the first ports 41 of the third pipe have two and are located at different positions, and the second port 22 of the first pipe 2 is different from the first port 41 above. The port 41 communicates, and the second port 32 of the second pipe 3 communicates with the first port 41 below. Of course, it can also be set that the second port 22 of the first pipe 2 communicates with the lower first port 41 , and the second port 32 of the second pipe 3 communicates with the upper first port 41 . Please refer to FIG. 3-3 and FIG. 3-4 respectively. The main difference from that shown in FIG. 2 is that the distribution shape of the first pipe 2 and the second pipe 3 is the same as that when the first port extends to the top surface 11 . The shape is slightly different. The combined shape of the first duct 2, the second duct 3 and the third duct 4 shown in Figs. 3-1 to 3-4 is also in a "Y" shape as a whole. Of course, it should be understood that the "Y" shape in this embodiment is not limited to those shown in the above examples, and other modifications can also be used, which will not be repeated here.

In some other setting examples, please refer to FIGS. 3-5 , the main difference from that shown in FIG. 2 is that the first port 21 of the first pipe 2 and the first port 31 of the second pipe 3 are also located on the top surface 11 , but the second port 42 of the third conduit 4 is located on the first side 13 adjacent to the top surface 11 . The combined shape of the first pipe 2, the second pipe 3 and the third pipe 4 shown in Figs. 3-5 is also "Y" shaped as a whole. In this setting example, the combined shape of the first pipe 2 , the second pipe 3 and the third pipe 4 can also be other shapes. For example, please refer to FIGS. 3-6 , and the combined shape is similar to that of an arrow. shape.

In some examples of this embodiment, the first ports of the first conduit and the second conduit, and the second port of the third conduit may be disposed on different surfaces of the transfer head body, respectively. For example, see Figure 4-1 and Figure 4-4.

In Figure 4-1, the transfer head body 1 is provided with a first pipe 2, a second pipe 3 and a third pipe 4, wherein the combined shape of the first pipe 2, the second pipe 3 and the third pipe 4 is " Y" shape. The first port 21 of the first pipe 2 is located on the first side 13 of the transfer head body 1, the first port 31 of the second pipe 3 is located on the second side 14 of the transfer head body 1, and the second port 22 of the first pipe 2 , the second port 32 of the second pipe 3 is located inside the transfer head body 1 and communicates with the first port 42 of the third pipe 4 ; the second port 42 of the third pipe 4 is located on the bottom surface 12 of the transfer head body 1 .

The main difference between the transfer head shown in FIG. 4-2 and that shown in FIG. 4-1 is that the first port 21 of the first pipe 2 extends to the first side surface 13 , and the first port 31 of the second pipe 3 extends The shape of the second side surface 14 of the transfer head body 1 is slightly different from that shown in FIG. 4-1 , but the combined shape of the first pipe 2 , the second pipe 3 and the third pipe 4 is also a “Y” shape.

The main difference between the transfer head shown in Fig. 4-3 and that shown in Fig. 4-1 is that the combined shape of the first pipe 2, the second pipe 3 and the third pipe 4 is a "T" shape.

The main difference between the transfer head shown in FIG. 4-4 and that shown in FIG. 4-1 is that the first port 21 of the first pipe 2 is located on the first side 13 of the transfer head body 1 , and the first port 31 of the second pipe 3 is located on the first side 13 of the transfer head body 1 . Located on the top surface 14 of the transfer head body 1 , the second port 22 of the first pipe 2 and the second port 32 of the second pipe 3 are located inside the transfer head body 1 and communicate with the first port 42 of the third pipe 4 ; The second port 42 of the third pipe 4 is located on the bottom surface 12 of the transfer head body 1 .

It can be seen from the above examples that in this embodiment, the specific location distribution of the first pipeline, the second pipeline and the third pipeline on the transfer head body and the combined form can be set flexibly. For example, as shown in the above examples, the combined shape of the first pipe, the second pipe and the third pipe in this embodiment may be, but not limited to, a Y-shaped or T-shaped shape, and may also be other shapes. In some examples of this embodiment, when the first pipe, the second pipe and the third pipe are combined into a Y shape, the angle between the first pipe and the second pipe may be, but not limited to, 30° to 150°, for example It can be set to 30° to 60°, or 60° to 120°, etc. For example, the angle θ between the first pipe 2 and the second pipe 3 in FIG. 4-1 can be, but not limited to, 30°, 60°, 90° °, 100°, 120°, 140°, 150°, etc.

In order to further improve the chip transfer efficiency, as shown above, in this embodiment, a plurality of transfer units may be arranged on the transfer head body, and the plurality of transfer units are arranged in an array on the transfer head body, and the second ports of the plurality of third pipes The position distribution on the third surface corresponds to the position distribution of each chip bonding area on the circuit board for bonding the micro-flip-chip LED chips. For example, please refer to Fig. 5-1 for an example of an arrangement. In Fig. 5-1, a plurality of transfer units are formed, and the plurality of transfer units are arranged in an array. The position distribution of the third surface corresponds to the position distribution of each chip bonding area on the circuit board for bonding the micro flip-chip LED chips. That is, the distance between adjacent second ports 42 is the same as or substantially the same as the distance between the center points of adjacent die bonding pads. When in use, please refer to Fig. 5-2, the connecting pipe 5 for transmitting the chip drip can be connected to the first port of each first pipe 2, and the connecting pipe 6 for transmitting the solder drip can be used to connect with each first port. The first port of the second pipe 2 is connected. Then, through the connecting pipe 5 and the connecting pipe 6, the chip drop and the solder drop are respectively delivered to the transfer head to transfer and weld the chips. The chip droplets and solder droplets in this example can be delivered in, but not limited to, a single droplet.

When using the transfer head exemplified in this embodiment to transfer the micro-flip-chip LED chip, the micro-flip-chip LED chip and the solder can be directly dropped from the first pipe and the second pipe on the transfer head through the third pipe in the form of droplets. It directly flows out and falls on the corresponding chip bonding area, eliminating the need to use the traditional transfer process using the first temporary substrate and the second temporary substrate, which can simplify the transfer steps of micro-flip-chip LED chips and improve the convenience of micro-flip-chip LED chip transfer. performance and transfer efficiency; at the same time, it enriches the transfer methods of micro-flip-chip LED chips.

An optional embodiment:

It should be understood that, in this embodiment, the manufacturing method of the transfer head of the above example is not limited, as long as the transfer head of the above example structure can be obtained. For ease of understanding, this embodiment is described below in conjunction with a method for manufacturing the above-mentioned transfer head as an example, please refer to Figures 6-1 to 6-2, including but not limited to:

S601: Form a first substrate layer.

Here, the first substrate layer is a part of the body of the transfer head, and its material is not limited, for example, it may be, but not limited to, polydimethylsiloxane, polymethyl methacrylate, or thermoplastic polyurethane elastomer. In this example, the first substrate layer can be formed on the substrate, and the substrate can be, but not limited to, any one of a glass substrate, a sapphire substrate, a quartz substrate, and a silicon substrate.

Referring to FIG. 6-2 , the form of the formed first substrate layer 61 may refer to the form shown in S601 . However, it is not limited to this form.

S602: forming a photoresist layer on the first substrate layer. The photoresist layer in this embodiment may be a positive type photoresist layer or a negative type photoresist layer, which can be flexibly selected according to requirements.

Referring to FIG. 6-2 , the shape of the formed photoresist layer 62 may refer to the shape shown in S602 . However, it is not limited to this form. The sides of the first substrate layer of the photoresist layer 62 are flush.

S603: After exposing and developing the photoresist according to the channel distribution diagram, a photoresist layer is left in the corresponding regions where the first channel, the second channel and the third channel are arranged.

Referring to FIG. 6-2, a mask plate 64 can be used, and a corresponding pipeline distribution diagram is formed on the mask plate 64, and the formed photoresist layer 62 is exposed and developed, and the first pipeline and the second pipeline are arranged. All other photoresist layers except the corresponding area of the third pipe are removed, and the remaining photoresist layers form the first pipe, the second pipe and the third pipe, please refer to the form shown in Figure 6-2 corresponding to S603 .

S604: Disposing a second substrate layer covering the entire photoresist layer on the first substrate layer to form a transfer head body, see FIG. 6-2 corresponding to the form shown in S603.

S605: After the photoresist layer is washed away with the target solution, the space originally occupied by the photoresist layer constitutes the first conduit, the second conduit and the third conduit. Refer to the form shown in Fig. 6-2 corresponding to 63 in S605.

For a form of the final transfer head obtained in S605, please refer to Fig. 6-3, which includes a transfer head body, a Y-shaped pipe formed in the transfer head body, including a first pipe 631, a second pipe 632 and a first pipe 632. Three pipes 633 , the first port 6311 of the first pipe 631 and the first port 6321 of the second pipe are located on the top surface 611 , the second port 6312 of the first pipe 631 and the second port 6322 of the second pipe are located on the transfer head body 61 Inside, it is connected to the first port 6331 of the third pipe 633 , and the second port 6332 of the third pipe 633 is located on the bottom surface 612 .

It can be seen that the manufacturing method of the transfer head provided in this example is simple and feasible, which is beneficial to the mass production and promotion of the transfer head, and is beneficial to the control of the manufacturing cost of the transfer head.

Another optional embodiment:

For ease of understanding, this embodiment below describes a chip transfer system using the transfer head of the above example, as an example, please refer to FIG. 7 , which includes a first container 71 , a second container 72 , a microfluidic control Device 73, connecting tube 75, and transfer head 74, wherein:

The first container 71 is used to hold the solution mixed with the micro-flip-chip LED chips, and the micro-flip-chip LED chips are in a suspended state in the solution. In this embodiment, the solution in the first container 71 can be, but is not limited to, a polymer solution that will not cause damage to the LED chip. That's it.

The second container 72 is used to hold the solder solution; in one example, the solder solution contained in the second container 72 may be solder having self-aggregation properties or coffee cup effect properties. When the solder with self-aggregation properties is heated, the solder will shrink and accumulate at the electrodes of the chip within 1 min after reaching the set temperature. For solders with coffee cup effect properties (such as but not limited to nano-metal (such as nano-silver or nano-copper) inks), the solvent volatilizes under the thermal effect, the metal ions are precipitated and stacked together and solidified, there is a coffee ring effect, wherein the conductive The particles migrate to the edge and gather at the electrodes of the chip. Therefore, the use of solder with self-aggregation properties or coffee cup effect properties will not cause a short circuit as a whole.

The microfluidic control device has a first feeding port 731, a second feeding port 732, a first feeding port 733 and a second feeding port 734, wherein the first feeding port 731 and the second feeding port 732 are respectively connected by The pipe 75 is connected to the liquid outlets of the first container 71 and the second container 72, the first material outlet 733 and the second material outlet 734 are respectively connected to the first port 741 of the first pipe and the first port 742 of the second pipe, The second port of the third pipe is aligned with the chip bonding area 761 on the circuit board 76 for soldering the miniature flip-chip LED chip; the bit flow control device can be, but not limited to, a peristaltic pump, which can control the solder in the second container 72 The solution-forming solder droplets flow into the second pipe, and flow out to the chip bonding area 761 through the second port of the third pipe, and control the solution mixed with the micro flip-chip LED chips in the first container 71 to form chip droplets via The connecting pipe flows into the first pipe, and flows out through the second port of the third pipe to the die bonding area 761 , so as to complete the transfer and die bonding of the chip.

It should be understood that the micro-flip-chip LED chip in this embodiment includes, but is not limited to, an epitaxial layer and electrodes. This embodiment does not limit the specific structure of the epitaxial layer of the micro-flip-chip LED chip. The epitaxial layer of the LED chip may include an N-type semiconductor, a P-type semiconductor, and an active layer between the N-type semiconductor and the P-type semiconductor. The active layer may include a quantum well layer, and may also include other structures. In other examples, optionally, the epitaxial layer may further include at least one of a reflective layer and a passivation layer. The material and shape of the electrode in this embodiment are also not limited. For example, in an example, the material of the electrode may include but not limited to Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, at least one of Ag.

It should be understood that the micro-flip-chip LED chip in this embodiment may be a micro-LED flip-chip; in another example, the micro-flip-chip LED chip may be a mini-LED flip-chip.

It should be understood that the micro flip-chip LED chip in this embodiment can also be replaced with other micro devices according to requirements in other application scenarios.

In some application examples of this embodiment, the microfluidic control device controls the flow rate of the solder droplet and the chip droplet to be 1 mm/s to 10 mm/s, which can be flexibly set according to requirements.

In some application examples of this embodiment, the microfluidic control device can control the solder droplets and the chip droplets to flow into the third conduit at the same time, so that after the solder droplets and the chip droplets converge and combine in the third conduit, they flow through the third conduit. The second port of the pipe simultaneously flows out to the die bond pad. For example, when the path lengths of the solder droplets and the chip droplets flowing into the third pipeline are the same, the microfluidic control device can control the flow rates of the solder droplets and the chip droplets to be the same; When the path lengths are different, the microfluidic control device can control the flow rate of the shorter path to be lower than the flow rate of the longer path. In this application example, due to the higher density of the micro-flip-chip LED chip on the side where the metal electrodes are arranged, the center of gravity of the micro-flip-chip LED chip is deviated to the side where the metal electrodes are arranged, so it can be ensured that the micro-LED chip falls into the chip Always keep the side with the electrodes facing down when welding the area. In addition, in this application example, since the solder droplet has an affinity with the metal electrode, in the third pipe, after the solder droplet and the chip droplet are combined, the solder droplet is generally located in the micro-flip-chip LED chip arrangement There is a side with a metal electrode, so it can further ensure that the side with the electrode is always kept facing down when the micro LED chip falls into the chip bonding area, which improves reliability.

In other application examples of this embodiment, the microfluidic control device can control the solder droplet to flow into the third pipe first, and then the chip to flow into the third pipe after the droplet, which can also ensure that when the micro LED chip falls into the chip bonding area is located, its electrodes are located above the corresponding solder. That is to say, the microfluidic control device can control the chip dripping into the third pipeline later than the solder dripping, so that after the solder dripping flows out through the second port of the third pipeline and falls to the chip bonding area, the chip dripping will pass through the third pipeline. The outflow from the second port of the three-pipe falls to the die bonding area and is above the solder droplet. For example, when the path length of the solder droplet and the chip droplet flowing into the third pipe is the same, the microfluidic control device can control the flow rate of the solder droplet and the chip droplet to be greater than that of the chip droplet; for the solder droplet and the chip droplet to flow into the third pipe When the path length of the pipeline is different, when the path of the solder drop is short, the flow rate of the solder drop can be controlled to be the same as that of the chip drop, or slightly larger than the flow rate of the chip drop. When the path of the chip drop is short, it can be controlled. The flow rate of the solder droplet is controlled to be greater than the flow rate of the chip droplet to ensure that the solder droplet is limited to the chip droplet and falls on the chip bonding area.

Optionally, in some application scenarios of this embodiment, the chip transfer system may further include, but is not limited to, a mobile control device. The mobile control device includes a mobile carrier and a mobile drive device. The transfer head is arranged on the mobile carrier, and the mobile drive The device can drive and control the mobile carrier to move to a specified position, for example, drive and control the mobile carrier to move so that the position of the transfer head is aligned with the chip bonding area where the micro LED chip needs to be placed next. It should be understood that, in some application examples, at least one of the above-mentioned first container, second container and microfluidic control device may also be disposed on the moving carriage together with the transfer head, and move together with the moving carriage. An example of the movement control process is shown in FIG. 8 . After the transfer head 73 transfers one of the micro-flip-chip LED chips to the chip bonding area 761 , a form of convergence and combination of the solder solution and the chip solution is shown in FIG. 77 . shown, and then the mobile control device controls the transfer head to move to the next chip bonding area in the direction of the arrow in the figure.

This embodiment also provides a method for chip transfer by using the chip transfer system of the above example, including:

The liquid solder in the chip bonding area is cured (the solder may be cured by, but not limited to, thermal curing or laser welding), so that the chip is bonded to the chip bonding area.

Optionally, in order to improve the yield, in some application examples, before curing the liquid solder in the chip bonding area, the method further includes:

Detect the position of each chip in the chip bonding area, and remove or replace the chip with inaccurate position alignment. For example, through but not limited to infrared, charge-coupled element (charge Coupled device camera, CCD) camera, etc., for each micro-flip-chip LED chip on the chip bonding area, for the chip that is placed crookedly, or not in the chip bonding area, or the chip with the electrode side on top, etc. For chips with inaccurate positions, remove or replace such chips to avoid dead spots after soldering.

This embodiment also provides a display panel and a manufacturing method of the display panel. The display panel includes a circuit board, and a plurality of chip bonding areas (ie, die bonding areas) are arranged on the circuit board. In the manufacturing method of the display panel, the But it is not limited to the micro LED chip transfer method exemplified in the above embodiment, and the micro flip-chip LED chip is transferred to the corresponding chip bonding area to complete the bonding.

This embodiment also provides a display device, which can display various electronic devices using display panels made of micro LED chips, such as but not limited to various smart mobile terminals, PCs, monitors, and electronic advertising boards. etc., wherein the display panel of the display device can be made by, but not limited to, the manufacturing method of the above-mentioned display panel.

It can be seen that the chip transfer system and transfer method provided in this embodiment can be combined with microfluidic technology, and the micro-flip-chip LED chip (which can also be replaced with other micro-devices) and ink-type solder are passed through T-type or Y-type microfluidic control The chip pipes are transferred to the welding area of the circuit board together, and then the LED chips are welded to the electrodes of the backplane circuit by photon or laser sintering, so as to achieve electrical conduction. The transfer process is simple and efficient, which is more conducive to the application and promotion of micro-flip-chip LED chips.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims

A transfer head, characterized in that, comprising:

Transfer head body;

at least one transfer unit formed on the transfer head body;

The transfer unit includes a first pipeline, a second pipeline and a third pipeline located in the transfer head body, and the first ports of the first pipeline and the second pipeline are located on the first surface and the first surface of the transfer head, respectively. On both sides, the second ports of the first pipe and the second pipe are respectively located in the transfer head body and communicate with the first port of the third pipe, and the second port of the third pipe is located in the transfer head body. the third side of the transfer head;

The first port of the first pipe is for the chip droplets wrapped with the micro-flip-chip LED chip to flow into the third pipe; the first port of the second pipe is for the droplets of solder The liquid flows in and flows into the third pipe through the second port thereof; the chip droplets and solder drops flowing into the third pipe flow out through the second port of the third pipe.
The transfer head according to claim 1, characterized in that, the first surface and the second surface of the transfer head are two opposite surfaces, or are the same surface.
The transfer head of claim 2, wherein the first conduit, the second conduit and the third conduit are combined into a Y-shape or a T-shape.
The transfer head according to claim 3, wherein when the first pipeline, the second pipeline and the third pipeline are combined into a Y shape, the included angle between the first pipeline and the second pipeline is 30° to 150°.
The transfer head according to any one of claims 1-4, wherein the material of the transfer head body is polydimethylsiloxane, polymethyl methacrylate, or thermoplastic polyurethane elastomer.
The transfer head according to any one of claims 1-4, wherein a plurality of the transfer units are formed on the transfer head body, and the plurality of transfer units are arranged on the transfer head body Distribution, the position distribution of the second ports of the plurality of third pipes on the third surface corresponds to the position distribution of each chip bonding area on the circuit board for bonding the micro flip-chip LED chips.
A method of making a transfer head as claimed in any one of claims 1-6, characterized in that, comprising:

forming a first substrate layer;

forming a photoresist layer on the first substrate layer;

After exposing and developing the photoresist according to the pipeline distribution diagram, a photoresist layer is left in the corresponding areas where the first pipeline, the second pipeline and the third pipeline are arranged;

A second substrate layer covering all the photoresist layer is arranged on the first substrate layer;

After the photoresist layer is washed away with the target solution, the space originally occupied by the photoresist layer constitutes the first conduit, the second conduit and the third conduit.
A chip transfer system, characterized in that it comprises a first container, a second container, a microfluidic control device, a connecting pipe and the transfer head according to any one of claims 1-6;

The first container is used for holding the solution mixed with the micro-flip-chip LED chips, the micro-flip-chip LED chips are in a suspended state in the solution, and the second container is used for holding the solder solution;

The first feed port and the second feed port of the microfluidic control device are respectively connected to the liquid outlet of the first container and the second container through the connecting pipe, and the first discharge port of the bit flow control device The port and the second discharge port are respectively connected to the first ports of the first pipe and the second pipe, and the second port of the third pipe is aligned with the circuit board for soldering the micro-flip-chip LED chip. chip bonding area; the bit flow control device controls the solder solution in the second container to form solder droplets that flow into the second pipe, and flow out through the second port of the third pipe to the chip bonding and control the solution mixed with the micro flip-chip LED chips in the first container to form chip droplets into the first pipe through the connecting pipe, and flow out through the second port of the third pipe. to the die pad.
The chip transfer system according to claim 8, wherein the microfluidic control device controls the solder drop and the chip drop to flow into the third pipeline at the same time, so that the solder drop and all After the chip droplets are converged and combined in the third pipe, they flow out and fall to the chip bonding area through the second port of the third pipe at the same time.
9. The chip transfer system according to claim 8, wherein the microfluidic control device controls the chip droplets to flow into the third pipeline later than the solder droplets, so that the solder droplets pass through the After the second port of the third pipe flows out and falls to the chip bonding area, the chip dripping liquid flows out and falls to the chip bonding area through the second port of the third pipe, and is located in the solder dripping liquid. above.
The chip transfer system according to any one of claims 8 to 10, wherein the microfluidic control device controls the flow rate of the chip droplet and the solder droplet to be 1 mm/s to 10 mm/s .
The chip transfer system according to any one of claims 8-10, wherein the solder is solder with self-aggregation properties or coffee cup effect properties.

13. The chip transfer system according to any one of claims 8-10, further comprising a mobile control device, the mobile control device comprising a mobile carrier and a mobile drive device, and the transfer head is disposed on the On the mobile carrier, the mobile drive device controls the mobile carrier to move to a designated position.
A chip transfer method utilizing the chip transfer system described in any one of 8-13, characterized in that, comprising:

The solder solution in the second container is controlled by the microfluidic control device to form solder droplets that flow into the second pipe, and flow out and fall to the chip bonding area through the second port of the third pipe, and Controlling the solution encapsulating the micro-flip-chip LED chip in the first container to form a chip droplet flows into the first pipe through the connecting pipe, and flows out to the chip through the second port of the third pipe welding area;

The liquid solder in the die bonding area is solidified, so that the die is bonded to the die bonding area.
The chip transfer method according to claim 14, wherein before the solidifying the liquid solder in the chip bonding area, the method further comprises:

The position detection is performed on each chip in the chip bonding area, and the chips with inaccurate positional alignment are rejected or replaced.