CN103390715B - A kind of LED of AlSiC composite base plate encapsulation - Google Patents

Abstract

The invention discloses an LED packaged with an AlSiC composite substrate, comprising an AlSiC composite heat dissipation substrate whose surface is sequentially plated with a copper film and a silver film, an LED light source module, a gold wire and an alumina ceramic frame; the LED light source module is packaged in an AlSiC on the composite heat dissipation substrate; the alumina ceramic frame is arranged on the outside of the LED light source module and bonded to the LED light source module; the alumina ceramic frame is plated with two copper film electrodes, and the two copper film electrodes are connected to each other through gold wires and The positive and negative poles of the LED light source module are connected. The thermal expansion coefficient of the LED and the AlSiC composite substrate of the invention matches that of the LED chip material, and the LED chip packaged on the board is not easy to fall off, thereby improving the service life of the LED.

Description

A kind of LED packaged with AlSiC composite substrate

technical field

The invention relates to an LED packaged on a board, in particular to an LED packaged with an AlSiC composite substrate.

Background technique

With the development of microelectronic devices in the direction of high performance, light weight and miniaturization, microelectronics puts forward more and more stringent requirements for packaging materials. Traditional packaging materials include silicon substrates, metal substrates, and ceramic substrates. Silicon and ceramic substrates are difficult to process, high in cost, and low in thermal conductivity; the thermal expansion coefficient of metal materials does not match that of microelectronic chips, which will cause thermal stress and warp during use. Therefore, it is difficult for these traditional packaging materials to meet the demanding requirements of packaging substrates. This is especially important for high power LEDs.

Newly developed heat dissipation substrate materials at home and abroad include metal core printed circuit board (MCPCB), copper-clad ceramic board (DBC) and metal-based low-temperature sintered ceramic substrate (LTCC-M). Among them, the thermal conductivity of the metal core printed circuit board is limited by the insulating layer, the thermal conductivity is low, and on-board packaging cannot be realized; the copper-clad ceramic board adopts a direct bonding method to bond ceramics and metals together, which improves the thermal conductivity. At the same time, the thermal expansion coefficient is controlled in an appropriate range, but the reaction ability of metal and ceramics is low, and the wettability is not good, which makes the bonding difficult, the interface bonding strength is low, and it is easy to fall off; The requirements for dimensional accuracy are high and the process is complicated. There are also problems of poor wettability and easy falling off of metal and ceramics.

Contents of the invention

In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the object of the present invention is to provide an LED packaged with an AlSiC composite substrate, the AlSiC composite substrate matches the thermal expansion coefficient of the LED chip material, and the LED chip packaged on the board is not easy to fall off, improving LED lifespan.

The object of the present invention is achieved through the following technical solutions:

An LED packaged with an AlSiC composite substrate, comprising an AlSiC composite heat dissipation substrate whose surface is sequentially plated with a copper film and a silver film, an LED light source module, a gold wire, and an alumina ceramic frame; the LED light source module is packaged on the AlSiC composite heat dissipation substrate The alumina ceramic frame is arranged on the outside of the LED light source module, and is bonded to the LED light source module; two copper film electrodes are plated on the alumina ceramic frame, and the two copper film electrodes pass through the gold wire and the LED light source module respectively. Positive and negative connections.

The copper film includes a first layer of copper film and a second layer of copper film. The first layer of copper film is prepared on the surface of the AlSiC composite heat dissipation substrate by electroless plating, and the second layer of copper film is prepared on the surface of the AlSiC composite heat dissipation substrate by electroplating. Surface preparation of the first copper film.

The thickness of the first layer of copper film is 0.8-1 μm.

The thickness of the second layer of copper film is 10-20 μm.

The silver film is prepared by cyanide-free electroplating.

The LED light source module is packaged on an AlSiC composite heat dissipation substrate by adopting a COB (chip on board, COB for short) packaging process.

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

(1) The present invention adopts AlSiC composite heat dissipation substrate. AlSiC composite materials are cheap in raw materials, can form complex shapes near net, and have high thermal conductivity, adjustable expansion coefficient, high specific stiffness, and low density. The LED structure of the present invention is simple , Good heat dissipation performance, the composite substrate and the thermal expansion coefficient of the LED chip material match, so that the LED chip packaged on the board is not easy to fall off, the service life of the LED is improved, and it has the advantages of high power density, high reliability and light weight. .

(2) The AlSiC composite heat dissipation substrate of the present invention is sequentially coated with a first layer of copper film, a second layer of copper film and a silver film. After silver coating, the reflectivity of the substrate can be improved, and the light extraction efficiency of the LED light source module can be improved. It is suitable for high-efficiency large Manufacture of power LEDs.

(3) The present invention uses an alumina ceramic frame package, and uses the ceramic frame as an insulating layer. AlSiC is a semiconductor material with a certain degree of conductivity. Directly making copper film electrodes on AlSiC substrates may cause short circuits. Therefore, on the AlSiC substrate, paste a ceramic frame around the LED chip, and make electrodes and other circuits on the ceramic, which can prevent the occurrence of short circuits. At the same time, the ceramic frame is low in cost, easy to install, and suitable for mass production.

Description of drawings

FIG. 1 is a cross-sectional view of an LED packaged with an AlSiC composite substrate according to Embodiment 1 of the present invention.

FIG. 2 is a top view of an LED packaged with an AlSiC composite substrate according to Embodiment 1 of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

As shown in Figures 1 and 2, an LED packaged with an AlSiC composite substrate in this embodiment includes an AlSiC composite heat dissipation substrate 1 coated with a copper film 2 and a silver film 3 on the surface in sequence, an LED light source module 4, a gold wire 6 and An alumina ceramic frame 8; the LED light source module 4 is packaged on the AlSiC composite heat dissipation substrate 1 using a COB packaging process; the alumina ceramic frame 8 is arranged outside the LED light source module 4 and bonded to the LED light source module 4; Two copper film electrodes 7 are plated on the alumina ceramic frame 8, and the two copper film electrodes 7 are respectively connected to the positive and negative poles of the LED light source module 4 through gold wires 6, and the transparent silica gel 5 wraps the gold wire 6, the copper film electrodes 7 and the Gold wire 6 connected parts.

The copper film includes a first layer of copper film and a second layer of copper film. The first layer of copper film is prepared on the surface of the AlSiC composite heat dissipation substrate by electroless plating, with a thickness of 0.8 μm; the second layer of copper film It is prepared on the surface of the first layer of copper film by electroplating, with a thickness of 10 μm.

The size of the LED light source module 4 can be 30mm*30mm, 40mm*40mm or 50mm*50mm, corresponding to LED light source modules with powers of 20W-40W, 40W-60W, 60W-100W respectively.

The preparation process of the LED packaged with the AlSiC composite substrate in this embodiment is as follows:

(1) Polish the unpolished AlSiC composite substrate to a mirror surface. After polishing, soak the AlSiC composite substrate with acetone and absolute ethanol respectively, and put it into an ultrasonic cleaner for cleaning for 15 minutes, so as to remove grease and other sundries attached to the substrate.

(2) Metallize the AlSiC composite substrate: the first layer of copper film is plated on the surface of the AlSiC composite substrate by electroless plating, with a thickness of 0.8 μm. The purpose of plating the first layer of copper film is to make the AlSiC composite substrate conductive and prepare for subsequent electroplating. The size of the first layer of copper film is consistent with the size of the LED light source module.

(3) Electroplating is used to plate a second layer of copper film on the surface of the first layer of copper film. The position and size of the second layer of copper film are consistent with those of the first layer of copper film, and the thickness is 10 μm.

(4) Plating a silver film on the surface of the second layer of copper film by cyanide-free electroplating, electroplating for 30 minutes at room temperature, the position and size of the silver film are consistent with the second layer of copper film.

(5) After the silver-plated film on the AlSiC composite substrate is processed, the LED light source module is packaged on the silver film according to the traditional on-board packaging method. An aluminum oxide frame is glued on the outside of the LED light source module; two copper film electrodes are plated on the aluminum oxide frame. Use gold wires to connect the two copper film electrodes to the positive and negative electrodes of the LED light source module respectively. Finally, wrap the gold wire, the part where the copper film electrode is connected to the gold wire with transparent silica gel.

Example 2

This embodiment is the same as Embodiment 1 except the following features.

The thickness of the first copper film of the LED packaged with the AlSiC composite substrate in this embodiment is 1 μm, and the thickness of the second layer copper film is 20 μm.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the embodiment, and any other changes, modifications, substitutions and combinations made without departing from the spirit and principle of the present invention , simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present invention.

Claims (5)

1. the LED with the encapsulation of AlSiC composite base plate, it is characterised in that include that surface is coated with copper successively The AlSiC composite radiating substrate of film and silverskin, LED light source module, gold thread and aluminium oxide ceramics frame；Institute State LED light source module to be encapsulated on AlSiC composite radiating substrate；Described aluminium oxide ceramics frame is located at LED Outside light source module, bonding with LED light source module；It is coated with two copper film electricity on described aluminium oxide ceramics frame Pole, two copper film electrodes are connected with the positive and negative electrode of LED light source module by gold thread respectively；Described copper film bag Including ground floor copper film and second layer copper film, described ground floor copper film uses the method for chemical plating to be combined at AlSiC Prepared by the surface of heat-radiating substrate, described second layer copper film uses electric plating method in the surface system of ground floor copper film Standby.

2. the LED of AlSiC composite base plate according to claim 1 encapsulation, it is characterised in that institute The thickness stating ground floor copper film is 0.8-1 μm.

3. the LED of AlSiC composite base plate according to claim 1 encapsulation, it is characterised in that institute The thickness stating second layer copper film is 10-20 μm.

4. the LED of AlSiC composite base plate according to claim 1 encapsulation, it is characterised in that institute Stating silverskin uses the method for cyanideless electro-plating to prepare.

5. the LED of AlSiC composite base plate according to claim 1 encapsulation, it is characterised in that institute Stating LED light source module uses COB packaging technology to be encapsulated on AlSiC composite radiating substrate.