CN207199666U - A kind of flip-chip COB substrates and light source product - Google Patents

Abstract

A kind of flip-chip COB substrates and light source product, the substrate include composite substrate, conductive circuit layer and insulating protective layer.Composite substrate by metal level with boron nitride layer is compound forms；Conductive circuit layer is arranged in the composite substrate and comprising the pad being arranged in pairs；Insulating protective layer is arranged on the same side of the composite substrate and exposes the pad with the conductive circuit layer.Therefore, the utility model comprehensively utilizes the advantage of various materials and obtains having concurrently the upside-down mounting COB substrates of high thermal conductivity, high reflectance, high stability and superior isolation performance and the LED encapsulation structure with high reliability or even bloom extraction efficiency.

Description

A flip-chip COB substrate and light source product

technical field

The utility model relates to a flip-chip COB substrate and a light source product.

Background technique

With the development of LED (Light Emitting Diode, Light Emitting Diode) technology and its wide application in the lighting industry, the market puts forward higher requirements for the luminous flux, light quality, reliability, and ease of installation of LEDs, so that COB ( The package form of chip on board) came into being.

With the continuous development of flip-chip (Flip-Chip) technology, the advantages of this structural chip will be fully displayed. Whether it is COB or Emitter package, the proportion of flip-chip technology products will continue to increase. However, there are contradictions between the various properties of the materials currently used in the packaging substrates involved in flip chip technology, such as thermal conductivity, insulation performance, stability and reflectivity. For example, mirror aluminum materials have high thermal conductivity, reflectivity and stability. properties, but its insulating electrical properties are poor; ceramic substrates have high stability and excellent insulation, but their reflectivity is low.

There are two main structures of flip-chip COB substrates commonly used at present: 1. Ceramic substrate (AlN or Al ₂ O ₃ )+copper foil. The base materials AlN and Al ₂ O ₃ have good insulation and thermal conductivity, but the thermal conductivity of Al ₂ O ₃ is only 20w/mk, and the heat dissipation performance is poor; AlN has high thermal conductivity compared to Al ₂ O ₃ , but the reflectivity is very low Poor and insufficient stability, not easy to co-fire with metal, high sintering temperature, complicated manufacturing process, the current domestic production technology is not mature, and the price is relatively high. 2. Metal substrate (Cu or Al) + insulating adhesive layer + copper foil. The thermal conductivity of copper and aluminum in the base material and the copper foil layer are very high, while the thermal conductivity of the insulating material epoxy (or silicone resin) is several hundred times worse than these two types of materials, resulting in the heat emitted by the LED chip The conduction to the insulating layer cannot diffuse out quickly, so that the heat is concentrated in the insulating layer, forming a thermal bottleneck. As a result, the junction temperature of the chip cannot be lowered, causing the light decay of the LED to increase rapidly, and the service life and reliability to be reduced.

Utility model content

In view of this, in order to overcome the defects and deficiencies in the prior art, the utility model provides a flip-chip COB substrate and a light source product.

Specifically, a flip-chip COB substrate proposed by the utility model includes:

The composite substrate is composed of a metal layer (1) and a boron nitride layer (2);

a conductive circuit layer (3), disposed on the boron nitride layer (2) of the composite substrate and comprising pads arranged in pairs; and

The insulating protective layer (4) is arranged on the same side of the composite base as the conductive circuit layer (3) and exposes the welding pad.

In a preferred embodiment, the material of the metal layer (1) of the composite substrate is aluminum or copper, and the thickness is 0.5-4 mm; the thickness of the boron nitride layer (2) of the composite substrate is set to 30- 100 microns; the boron nitride layer (2) is combined with the metal layer (1) by means of sputtering and vapor deposition.

In a preferred embodiment, the conductive circuit layer (3) is made of gold, silver or copper, and its thickness is 2-30 microns.

Specifically, the utility model proposes a light source product using a flip-chip COB substrate, which is characterized in that it includes the flip-chip COB substrate, a light-emitting chip (6), solder (5) and dam glue (8) and fluorescent glue (7), the chip (6) is welded on the conductive circuit layer (3) by solder (5), the periphery of the upper surface of the substrate is coated with dam glue (8), and the inside of the dam glue (8) is coated Covered with fluorescent glue (7).

As can be seen from the above description of the utility model, compared with the prior art, the utility model has the following beneficial effects:

The composite substrate of metal and boron nitride can well solve the conflicting problems among thermal conductivity, insulation, reflectivity and stability of existing flip-chip substrates. The advantages of various materials are comprehensively used to obtain a flip-chip COB substrate with high thermal conductivity, high reflectivity, high stability and excellent insulation performance, and an LED packaging structure with high reliability and even high light extraction efficiency.

The metal and boron nitride composite substrate has the following advantages: 1), high thermal conductivity: the thermal conductivity of boron nitride is 60W/mk, and the thermal conductivity of copper can reach 400W/mK; the composite substrate is better than the traditional alumina substrate or organic insulating layer The aluminum substrate has a higher thermal conductivity (the thermal conductivity of Al2O3 is 20W/mK, and the thermal conductivity of epoxy resin is 0.2W/mk); 2), good thermal shock resistance: the thermal expansion coefficient of boron nitride is 4.5×10 ^{- 6} /K, the thermal expansion coefficient of silicon is 4.1×10 ^-6 /K, the thermal expansion coefficient of sapphire is 8.8×10 ^-6 /K, high matching; 3), excellent electrical insulation performance: boron nitride breakdown voltage 30kv /mm; 4), good weather resistance: it has very good resistance to high temperature, high humidity, acid, high salt and other environments. At the same time, the composite substrate is composited by sputtering, vapor deposition and other processes, and the materials are tightly combined, and it is not easy to delaminate between different materials in extreme environments.

2. After many experiments, the thickness of the metal layer is 0.5-4 mm, and the thickness of the boron nitride layer is 30-100 microns. This thickness range is produced by taking into account the performance of thermal conductivity, insulation and mechanical strength, so that it conducts heat The effect is the best in terms of resistance, insulation and mechanical strength.

Description of drawings

FIG. 1 is a schematic top view of a flip-chip COB substrate.

FIG. 2 is a schematic cross-sectional view along line A-A of FIG. 1 .

FIG. 3 is a schematic top view of a light source product.

FIG. 4 is a schematic cross-sectional view along B-B of FIG. 3 .

Detailed ways

The utility model will be further described below through specific embodiments.

Referring to FIG. 1 and FIG. 2 , a flip-chip COB substrate includes: a composite substrate, a conductive circuit layer 3 and an insulating protection layer 4 .

The composite substrate is composed of a metal layer 1 and a boron nitride layer 2.

In this embodiment, the material of the metal layer 1 of the composite base is aluminum or copper, and the thickness is 0.5-4 mm; the thickness of the boron nitride layer 2 of the composite base is set to 30-100 microns; Layer 2 is combined with metal layer 1 by means of sputtering and vapor deposition.

The conductive circuit layer 3 is disposed on the boron nitride layer 2 of the composite substrate and includes pads arranged in pairs.

In this embodiment, the conductive circuit layer 3 is made of gold, silver or copper, and its thickness is 2-30 microns.

The insulating protection layer 4 is disposed on the same side of the composite substrate as the conductive circuit layer 3 and exposes the pad.

In this embodiment, the insulating protection layer 4 is disposed in the non-conductive area outside the light emitting area. The insulating protection layer 4 is a bismaleimide triazine system material layer and/or a low-temperature glass glaze layer, and the melting point of the low-temperature glass glaze layer is lower than 600°C.

Please refer to Figure 3 and Figure 4, which is a light source product using the above-mentioned flip-chip COB substrate, which includes the flip-chip COB substrate, light-emitting chip 6, solder 5, dam glue 8 and fluorescent glue 7, the chip 6 passes through The solder 5 is welded on the conductive circuit layer 3 , the outer surface of the upper surface of the substrate is coated with a dam glue 8 , and the inside of the dam glue 8 is coated with a fluorescent glue 7 .

The composite substrate of metal and boron nitride can well solve the conflicting problems among thermal conductivity, insulation, reflectivity and stability of existing flip-chip substrates.

The metal and boron nitride composite substrate has the following advantages: 1), high thermal conductivity: the thermal conductivity of boron nitride is 60W/mk, and the thermal conductivity of copper can reach 400W/mK; the composite substrate is better than the traditional alumina substrate or organic insulating layer The aluminum substrate has a higher thermal conductivity (the thermal conductivity of Al2O3 is 20W/mK, and the thermal conductivity of epoxy resin is 0.2W/mk); 2), good thermal shock resistance: the thermal expansion coefficient of boron nitride is 4.5×10 ^{- 6} /K, the thermal expansion coefficient of silicon is 4.1×10 ^-6 /K, the thermal expansion coefficient of sapphire is 8.8×10 ^-6 /K, high matching; 3), excellent electrical insulation performance: boron nitride breakdown voltage 30kv /mm; 4), good weather resistance: it has very good resistance to high temperature, high humidity, acid, high salt and other environments. At the same time, the composite substrate is composited by sputtering, vapor deposition and other processes, and the materials are tightly combined, and it is not easy to delaminate between different materials in extreme environments. After many experiments, the thickness of the boron nitride layer is The thermal conductivity of 30-100 microns is better.

The above is only a specific embodiment of the utility model, but the design concept of the utility model is not limited thereto, and any non-substantial modification of the utility model by using this concept should be an act of violating the protection scope of the utility model.

Claims (4)

1. A kind of 1. flip-chip COB substrates, it is characterised in that including：

   Composite substrate, by metal level (1) with boron nitride layer (2) is compound forms；

   Conductive circuit layer (3), is arranged in the composite substrate and comprising the pad being arranged in pairs；And

   Insulating protective layer (4), it is arranged on the same side of the composite substrate with the conductive circuit layer (3) and exposes the weldering Disk.
2. A kind of 2. flip-chip COB substrates as claimed in claim 1, it is characterised in that：The metal level (1) of the composite substrate Material be aluminium or copper, and thickness is 0.5-4 millimeters；The thickness of the boron nitride layer (2) of the composite substrate is arranged to 30-100 Micron；Boron nitride layer (2) is carried out compound by way of sputtering, being vapor-deposited with metal level (1).
3. A kind of 3. flip-chip COB substrates as claimed in claim 1, it is characterised in that：Conductive circuit layer (3) material is Gold, silver or copper, and its thickness is 2-30 microns.
4. A kind of 4. light source product of flip-chip COB substrates using described in claim 1,2 or 3, it is characterised in that：It includes Flip-chip COB substrates, luminescence chip (6), solder (5) and box dam glue (8) and fluorescent glue (7), luminescence chip (6) pass through Solder (5) is welded in conductive circuit layer (3), and surface periphery is coated with box dam glue (8) on substrate, and box dam glue applies within (8) It is covered with fluorescent glue (7).