Method for actively encapsulating LED chip and encapsulation structure thereof

A technology for LED chips and packaging methods, applied in electrical components, circuits, semiconductor devices, etc., can solve the problems of many processes, air bubbles, and high costs, and achieve the effects of simple packaging equipment, high process repeatability, and short production time.

Inactive Publication Date: 2009-11-18
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although some researchers have discovered these phenomena, the previous packaging process suffered from the inability to achieve such a multi-layer packaging structure
[0004] In terms of phosphor coating technology, the chip replica coating method and its derivative technology are mainly used at present. This coating method has poor light and color uniformity.
Chinese patent 200610034012.1 proposes a long-distance phosphor film packaging structure with a thermal isolation layer, but in this type of packaging structure and packaging method, the phosphor film and the outermost lens need to be prepared in advance with a mold, and the packaging structure There is a clear interface between the layers, and it is necessary to vacuumize the air bubbles at the interface to prevent total reflection at the interface. The production efficiency is low and the quality is difficult to guarantee.
Traditional packaging uses epoxy resin such as AB glue, which is packaged by heat curing. It needs to cure and post-cure the epoxy resin at a temperature higher than 100 degrees for a long time (more than 1 hour). There are many processes and low production efficiency. , long cycle and high cost
It specifically includes the following disadvantages: 1) The difficulty of process control is air bubbles, lack of material, and black spots; 2) In actual production, manual dispensing is often used, and the efficiency is low; 3) It needs molds to form, and most of them need lenses. In order to meet the optical design; 4) Large-scale industrial production requires high equipment requirements, and it is difficult for general enterprises to have enough funds to buy good equipment; 5) Thermal curing itself may affect the chip, causing the chip to be damaged due to high temperature
[0006] At present, some researchers use photosensitive resin to encapsulate light-emitting diodes to improve packaging efficiency, such as US Patent 6958250, but the packaging process in this patent is similar to the current LED packaging process, which requires the use of molds
Chinese patent 200710032491.8 provides a light-curing packaging method that does not require a mold, but the shape of the lens formed by this method is not ideal, the interface with the packaging substrate and the chip base is not tight, the mushroom-shaped structure is easy to fall off under force, and the The intensity and time of passing current are sensitive, not suitable for automatic production

Method used

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  • Method for actively encapsulating LED chip and encapsulation structure thereof
  • Method for actively encapsulating LED chip and encapsulation structure thereof
  • Method for actively encapsulating LED chip and encapsulation structure thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] figure 2 It is a schematic diagram of LED three-layer structure lens embodiment 1 of the present invention, and its structure includes the following parts: LED package support 12 (including support pin 13 and support base), chip 11, gold wire 10 connecting chip and LED support and A lens made of three layers of material. The material of the first layer of lens 9 is the photosensitive resin PE1 configured according to Table 1, the material of the second layer of lens 8 is the photosensitive resin PEP1 mixed with phosphor powder, and the material of the third layer of lens 7 is the same as that of the first layer, also according to Table 1 Configured photosensitive resin PE1.

[0043] The implementation steps of this embodiment are as follows:

[0044] (a) chip 11 is installed in the reflective cup in the LED packaging support 12;

[0045] (b) Complete the circuit connection between the chip and the support by punching gold wires;

[0046] (c) if Figure 4 As shown,...

Embodiment 2

[0063] figure 2 It is also a schematic diagram of Embodiment 2 of the LED three-layer structure lens of the present invention. The difference from Embodiment 1 is that the material of the first layer lens 9 is transparent silica gel (tentatively named S1), and the materials of other layers are the same.

[0064] The implementation steps of this embodiment are as follows:

[0065] (a) chip 11 is installed in the reflective cup in the LED packaging support 12;

[0066] (b) Complete the circuit connection between the chip and the support by punching gold wires;

[0067] (c) if Figure 4 As shown, the LED 22 is placed on the experimental board 21, the electrodes at both ends are connected to the power supply, and the surface of the LED chip 22 is kept parallel to the plane of the experimental board 21, and the LED 22 (that is, the chip 11, the chip base and the packaging support 12) is used. Resin 23 is pre-impregnated to effectively remove the air bubbles on the surface of th...

Embodiment 3

[0082] image 3 It is a schematic diagram of Embodiment 3 of the LED three-layer structure lens of the present invention. The refractive index of the three-layer lens gradually decreases from the inside to the outside, so that the light output efficiency is obviously improved. Its structure includes the following parts: LED packaging bracket 19 (including bracket pins) 20 and support base), chip 18, gold wire 17 connecting the chip and the LED support, and a three-layer structure lens. The material of the first layer of lenses 16 is doped with nanoparticles (such as TiO 2 ) of photosensitive resin (temporarily named PEN1), the material of the second layer of lens 15 is a photosensitive resin mixed with phosphor powder (tentatively named PEP1), and the material of the third layer of lens 14 is undoped photosensitive resin (tentatively named PE1).

[0083] The implementation steps of this embodiment are as follows:

[0084] (a) chip 18 is installed in the reflective cup in the...

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Abstract

The invention discloses an active encapsulation method which utilizes the spontaneous light of a chip to initiate photosensitive resin polymerization for the in-situ preparation of a lens with an LED single layer and multilayer structure. The method includes the following steps: photosensitive resin liquid wave band light which is sensitive to specific wave band light is prepared; an LED semi-finished product which is processed by electrode connection and die bond is presoaked in photosensitive resin for die bond; the LED semi-finished product is inverted to be soaked in the photosensitive resin liquid, low working current is led into and enables the LED chip to be luminous, photosensitive resin is triggered to generate preliminary polymerization, and a photosensitive resin core is formed on the luminous surface of the LED chip; the LED semi-finished product is separated from the surface of the photosensitive resin liquid, and the drops of the photosensitive resin liquid need to be attached to the photosensitive resin core and a chip base; the intermediate working current is led into and enables the LED chip to be luminous, and the drops of the photosensitive resin liquid are stimulated to be solidified; after the solidification of the drops of the photosensitive resin liquid, high working current is led into a sample so as to enable the LED chip to be luminous, and then the steps of solidification and decoloration are carried out, or the sample is irradiated by sunlight, purple light or ultraviolet light to be decolourized; and finally the sample processed by solidification and decoloration is cleaned.

Description

technical field [0001] The invention belongs to the technical field of packaging of light-emitting diodes, and in particular relates to an active packaging method of LED chips and a packaging structure thereof. Background technique [0002] As the application fields of light-emitting diodes (LEDs) continue to expand, the requirements for LED luminous efficiency are getting higher and higher. The luminous efficiency of LEDs is divided into two types: internal quantum efficiency and external quantum efficiency. The internal quantum efficiency refers to the efficiency of the electron-hole pairs of the LED chip recombining in the PN junction region to generate photons that emit on the surface of the chip, and the external quantum efficiency refers to the total efficiency of the light emitted by the LED chip being extracted to the outside of the package. At present, the internal quantum efficiency of LED has generally reached more than 70%-90%, but the external quantum efficiency...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L33/00
Inventor 刘立林王钢杨建福蔡苗苗
Owner SUN YAT SEN UNIV
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