CN115732486A

CN115732486A - Thin film LED chip matrix structure and manufacturing method

Info

Publication number: CN115732486A
Application number: CN202211368052.5A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Shanghai Dianshen Technology Co ltd
Current assignee: Shanghai Dianshen Technology Co ltd
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-03-03

Abstract

The invention discloses a thin film LED chip matrix structure and a manufacturing method thereof. Coating or pasting a film intermediate layer with a reducing functional group on the conductive circuit layer with the protrusions, wherein the surface of the film intermediate layer is in contact with the circuit layer; arranging thin film LED chips on the surface of the thin film interlayer; under the action of pressure and heat, the middle layer is melted, and the thin film LED chip penetrates through and is embedded into the middle layer; and the electrode of the thin film LED chip and the bulge of the conductive circuit layer are welded under the action of the reducing functional group contained in the thin film middle layer. The invention provides a thin film LED chip matrix structure and a manufacturing method thereof, and a thin film LED chip matrix with a reliable structure and a simple process can be obtained.

Description

Thin film LED chip matrix structure and manufacturing method

Technical Field

The invention relates to the technical field of photoelectric semiconductor display, in particular to a thin film LED chip matrix structure and a manufacturing method thereof.

Background

The micro LED is used as a novel display technology, is formed by taking an LED chip with a miniature size as a pixel, and has the characteristics of high brightness, high energy efficiency, high contrast and long service life compared with the existing mature LCD display and OLED display. The thin film LED chip is to meet the structural requirement of the chip size below 100um, remove the substrate of the LED by laser peeling to obtain the thin film chip with the thickness below 10um, and then transfer the thin film chip to a circuit in a large amount.

The thickness of the thin film LED chip is only 10um, the size of the thin film LED chip in the horizontal direction is 10-100 um, and the thin film LED chip is connected with a driving circuit, so that great difficulty exists. The traditional solder paste welding has the problems of difficult solder paste brushing and infirm welding; the anisotropic conductive adhesive has the problems of high cost, incapability of activating conductive particles by large-area hot pressing and poor connection reliability.

Meanwhile, the thin film LED chip also has a problem that a huge transfer process is complicated. Meanwhile, a typical thin film LED chip mass transfer requires at least three flips or transfers: the thin LED film chip is transferred from the sapphire substrate to a first middle adapter plate for the first time, and the electrode of the chip faces the first middle adapter plate; earning the thin film LED chip from the first intermediate adapter plate to the second intermediate adapter plate for the second time, wherein the chip electrode faces back to the second intermediate adapter plate; the third time is that the thin film LED chip is transferred to the circuit board, and the electrode of the chip faces the circuit board.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide a thin film LED chip matrix structure and a manufacturing method thereof.

The invention provides the following technical scheme:

the invention provides a thin film LED chip matrix structure which comprises a conductive circuit layer, a thin film middle layer and at least three inverted thin film LED chips, wherein the thin film middle layer covers the surface of the conductive circuit layer, and a plurality of thin film LED chips are fixed on the thin film middle layer at equal intervals.

As a preferred technical scheme of the invention, the conductive circuit layer is provided with a metal micro-protrusion electrode, and the height of the metal micro-protrusion is between 1um and 50 um.

In a preferred embodiment of the present invention, the film intermediate layer has a thickness of 10 μm or less, is a composite material containing a thermosetting component, and contains a reducing or acidic functional group for improving fluxing properties.

As a preferable technical scheme of the invention, the thickness of the thin film LED chip is less than 10um, the thickness of the thin film LED chip is lower than that of the thin film middle layer, the thin film LED chip comprises at least two electrodes, the electrodes comprise at least one weldable metal, and the electrodes of the thin film LED chip are in welding contact with the metal micro-protruding electrodes on the conductive circuit layer.

Correspondingly, the manufacturing method of the thin film LED chip matrix structure comprises the following steps:

step one, preparing a conductive circuit layer with a metal micro-protrusion on the surface;

step two, coating a film intermediate layer on the conducting circuit layer;

fixing the thin film LED chip on the thin film interlayer;

and step four, hot-pressing and bonding the thin film LED chip and the conducting circuit layer, enabling the bottom electrode of the thin film LED chip to be in contact with the metal micro-bump electrode on the surface of the conducting circuit layer, welding and contacting, and obtaining the thin film LED chip matrix after manufacturing.

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

the invention provides a thin film LED chip matrix structure and a manufacturing method thereof, and a thin film LED chip matrix with a reliable structure and a simple process can be obtained.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a diagram of a thin film LED chip matrix structure of the present invention (in the figure, a is a top view, and b is a front view);

FIG. 2 is a schematic view of a process for preparing a thin film LED chip matrix structure according to the present invention;

in the figure: 1. a conductive circuit layer; 2. a thin film intermediate layer; 3. a thin film LED chip.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation. Wherein like reference numerals refer to like parts throughout.

Example 1

Referring to fig. 1-2, the present embodiment is a thin film LED chip matrix and a method for manufacturing the same, wherein the thin film LED chip matrix includes a conductive circuit layer 1, a thin film intermediate layer 2, and at least three thin film LED chips 3.

The manufacturing process of the thin film LED chip matrix of the invention is as follows:

the preparation has bellied conducting wire layer 1, and the height of the little protruding of metal of conducting wire layer 1 is 2 ~ 5um, and there is the metal tin silver alloy of weldable at protruding top.

Then, a film intermediate layer 2 is applied on the conductive circuit layer 1 under a certain pressure and temperature. As a preferred embodiment of the invention, the thickness of the film intermediate layer 2 is 5-7 um, the film intermediate layer 2 is an epoxy resin precursor compound in a low polymerization state, and the film intermediate layer 2 contains components for removing oxidation and assisting welding.

The thin film LED chip 3 is transferred to the thin film intermediate layer 2 from the sapphire substrate in a laser stripping mode; the thickness of the thin film LED chip 3 is 7-8 um, and the size is 30umx60um; the defects, positions and angles of the thin film LED chip 3 are detected by AOI, photoluminescence and the like to confirm that the chip is not defective in advance, and the positions and deflection are within a design error range, so that the chip is ensured to be aligned with the protruding positions of the conducting circuit layer 1.

Then, at least placing a heat source on the bottom surface of the conductive circuit layer 1 and one surface of the top of the film thin LED chip 3 matrix for heating, so that the film middle layer 2 is melted; pressure is applied to the thin film LED chip 3 to embed it in the molten thin film interlayer 2. And welding the electrodes of the thin film LED chip 3 with the electrodes of the conductive circuit layer 1 at least by one of heating or ultrasonic vibration. Keeping a certain temperature to solidify the film intermediate layer 2;

step one, preparing a conductive circuit layer 1 with a metal micro-protrusion on the surface, as shown in (2-1) in fig. 2;

step two, coating a film intermediate layer 2 on the conductive circuit layer 1, as shown in (2-2) in fig. 2;

fixing the thin film LED chip 3 on the thin film interlayer 2 as shown in (2-3) of FIG. 2;

and step four, thermally pressing and bonding the thin film LED chip 3 and the conductive circuit layer 1, so that the bottom electrode of the thin film LED chip 3 is contacted with the metal micro-bump electrode on the surface of the conductive circuit layer 1, welding and contacting, and obtaining a thin film LED chip matrix after the manufacturing is finished, as shown in (2-4) in figure 2.

In fig. 1, a is a top view and b is a front view of the thin film LED chip matrix.

The thin film LED chip matrix with reliable structure and simple process can be obtained. The thin film LED chip matrix comprises a circuit layer, an intermediate layer and at least 3 thin film type LED chips. Coating or pasting a film intermediate layer 2 with a reducing functional group on the conductive circuit layer 1 with the protrusions, wherein the surface of the film intermediate layer 2 is in contact with the circuit layer; arranging thin film LED chips 3 on the surface of the thin film intermediate layer 2; under the action of pressure and heat, the film intermediate layer 2 is melted, and the film LED chip 3 penetrates through and is embedded into the film intermediate layer 2; the electrode of the thin film LED chip 3 and the protrusion of the conductive circuit layer 1 are welded under the action of the reducing functional group contained in the thin film middle layer 2.

In one embodiment of the thin film LED chip matrix, the conducting circuit layer 1 is a PCB printed circuit board, so that a low-cost and large-area thin film LED matrix can be realized; in another embodiment of the thin film LED chip matrix, the conductive circuit layer 1 is a glass plate containing ITO circuits or copper circuits, which can realize a transparent thin film LED matrix with high flatness and high chip density; in another embodiment of the thin film LED chip matrix, the conductive circuit layer 1 is a prefabricated silicon substrate containing a driving unit, which can realize an integrated module of the driving and light emitting units; in another embodiment of the thin film LED chip matrix, the conductive circuit layer 1 is a flexible circuit board, and a flexible thin film LED matrix can be realized.

In one embodiment of the present thin-film LED chip matrix, the metal micro-bumps on the conductive circuit layer 1 comprise at least one of gold, silver, copper, and tin.

In one embodiment of the present thin-film LED chip matrix, the thin-film interlayer 2 is a composite material containing an epoxy resin component. When the epoxy resin is coated on the conductive circuit layer 1, the number proportion of the residual uncrosslinked functional groups in the interior is more than 10% of the number proportion of all uncrosslinked functional groups of the epoxy resin precursor. In one embodiment of the present thin-film LED chip matrix, the thin-film interlayer 2 contains reductive functional groups which are one or more of hydroxyl, amino, aldehyde, and ketone groups. In one embodiment of the present thin-film LED chip matrix the thin-film interlayer 2 contains acidic functional groups that are one or a combination of carboxyl and sulfo groups.

In one embodiment of the present thin-film LED chip matrix, the thin-film interlayer 2 has a thickness of 5 to 7um, which is lower than the thickness of the thin-film LED chips 3.

In an embodiment of the thin film LED chip matrix, the precursor of the thin film intermediate layer 2 is in a film shape, and is applied on the conductive circuit layer 1 by a roller or vacuum bonding method, so as to obtain the thin film intermediate layer 2 with uniform film thickness and uniform material quality. In an embodiment of the thin film LED chip matrix, the precursor of the thin film intermediate layer 2 is in a liquid state, and is coated on the conductive circuit layer 1 by spin coating, and the viscosity and spin coating rotation speed of the precursor are adjusted, so that the film thicknesses with different thicknesses can be flexibly obtained.

In an embodiment of the thin film LED chip matrix, the thickness of the thin film LED chip 3 is 6-10 um, the thin film LED chip 3 includes two electrodes, the electrodes of the thin film LED chip 3 include gold-tin alloy, and the gold-tin electrodes of the thin film LED chip 3 and the micro-bump electrodes of the conductive circuit layer 1 form alloy welding.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described above, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a film LED chip matrix structure, its characterized in that includes thin film LED chip (3) of conducting wire layer (1), thin film intermediate level (2) and at least three flip-chip, the surface of conducting wire layer (1) coats and is stamped thin film intermediate level (2), and a plurality of thin film LED chips (3) are fixed in on thin film intermediate level (2) equidistant.

2. The thin film LED chip matrix structure of claim 1, wherein the conductive circuit layer (1) is provided with a metal micro-bump electrode, and the height of the metal micro-bump is between 1um and 50 um.

3. The thin film LED chip matrix structure of claim 1, wherein the thickness of said thin film interlayer (2) is less than 10um, said thin film interlayer is a composite material containing thermosetting component, said thin film interlayer contains reducing or acidic functional group for improving solderability.

4. A thin film LED chip matrix structure according to claim 3, wherein the thickness of said thin film LED chips (3) is below 10um, and the thickness of said thin film LED chips (3) is lower than the thickness of said thin film interlayer (2), said thin film LED chips (3) comprise at least two electrodes, said electrodes comprise at least one solderable metal, and the electrodes of said thin film LED chips (3) are in soldering contact with the metal micro-bump electrodes on said conductive circuit layer (1).

5. A manufacturing method of a thin film LED chip matrix structure is characterized by comprising the following steps:

step one, preparing a conductive circuit layer (1) with a metal micro-protrusion on the surface;

step two, coating a thin film intermediate layer (2) on the conductive circuit layer (1);

fixing the thin film LED chip (3) on the thin film intermediate layer (2);

and step four, hot-press bonding the thin film LED chip (3) and the conductive circuit layer (1) to enable a bottom electrode of the thin film LED chip (3) to be in contact with a metal micro-bump electrode on the surface of the conductive circuit layer (1) and to be in welding contact, and obtaining the thin film LED chip matrix after the manufacturing is finished.