阅读说明：本技术 便于散热的dfn封装器件 (DFN packaging device convenient for heat dissipation ) 是由 马磊 党鹏 杨光 彭小虎 王新刚 庞朋涛 任斌 王妙妙 于 2019-02-22 设计创作，主要内容包括：本发明公开了一种便于散热的DFN封装器件,其环氧绝缘体的原料包括以下重量份组分：环氧树脂80～100份、线型酚醛树脂50～70份、液体丁腈橡胶12～18份、焦碳酸二乙酯3～8份、硅微粉65～90份、聚乙二醇单辛基苯基醚0.1～1.5份、3-氨基丙基三乙氧基硅烷2～5份、醋酸丁酸纤维素2～6份、5-氟-2-甲氧基苯胺0.3～2份、2,4,6-三(二甲氨基甲基)苯酚0.5～5份、脱模剂1～5份、阻燃剂10～25份；该便于散热的DFN封装器件散热效果、力学性能优异,封装结构稳定可靠,具有广阔的应用前景。(The invention discloses a DFN packaging device convenient for heat dissipation, wherein the raw materials of an epoxy insulator comprise the following components in parts by weight: 80-100 parts of epoxy resin, 50-70 parts of novolac resin, 12-18 parts of liquid nitrile rubber, 3-8 parts of diethyl pyrocarbonate, 65-90 parts of silica powder, 0.1-1.5 parts of polyethylene glycol mono-octyl phenyl ether, 2-5 parts of 3-aminopropyl triethoxysilane, 2-6 parts of cellulose acetate butyrate, 0.3-2 parts of 5-fluoro-2-methoxyaniline, 0.5-5 parts of 2,4, 6-tris (dimethylaminomethyl) phenol, 1-5 parts of a release agent and 10-25 parts of a flame retardant; the DFN packaging device convenient for heat dissipation has the advantages of excellent heat dissipation effect and mechanical property, stable and reliable packaging structure and wide application prospect.)

1. The utility model provides a DFN encapsulates device convenient to heat dissipation which characterized in that: the LED packaging structure comprises a radiating pad (1) positioned in an epoxy insulator (6), a chip (3) and a conductive pad (4), wherein the chip (3) is positioned on the radiating pad (1), a plurality of conductive pads (4) are arranged on the periphery of the radiating pad (1), and the conductive pad (4) is connected with the chip (3) through a lead (5);

a sunken groove (11) for embedding the chip (3) is formed in the central area of the heat dissipation coil (1), so that a cofferdam part (12) is formed in the edge area of the heat dissipation coil (1), silver paste layers (2) are arranged between the bottom of the sunken groove (11) and the cofferdam part (12) and the lower surface and the side wall of the chip (3), a plurality of heat exchange blind holes (13) extending into the heat dissipation coil (1) are formed in the bottom of the sunken groove (11), and silver paste filling parts (21) are arranged in the heat exchange blind holes (13);

the epoxy insulator (6) comprises the following raw materials in parts by weight: 85 parts of epoxy resin, 50 parts of novolac resin, 18 parts of liquid nitrile rubber, 3 parts of diethyl pyrocarbonate, 65 parts of silicon micropowder, 1.5 parts of polyethylene glycol mono-octyl phenyl ether, 3 parts of 3-aminopropyl triethoxysilane, 2 parts of cellulose acetate butyrate, 0.3 part of 5-fluoro-2-methoxyaniline, 0.5 part of 2,4, 6-tris (dimethylaminomethyl) phenol, 2 parts of a release agent and 25 parts of a flame retardant.

2. The DFN packaged device for facilitating heat dissipation of claim 1, wherein: the depth of the sinking groove (11) is not more than the thickness of the chip (3).

3. The DFN packaged device for facilitating heat dissipation of claim 1, wherein: the flame retardant is borate and/or molybdate.

4. The DFN packaged device for facilitating heat dissipation of claim 1, wherein: the silicon micropowder is fused silicon micropowder.

Technical Field

The invention belongs to the technical field of semiconductor devices, and particularly relates to a DFN packaging device convenient for heat dissipation.

Background

The DFN is a leadless package, which is square or rectangular, a large-area exposed bonding pad is arranged at the center of the bottom of the package for heat conduction, and a conductive bonding pad for realizing electrical connection is arranged around the periphery of the package surrounding the large bonding pad. DFN packages provide excellent electrical performance and are widely used because they do not have gull-wing leads, as do conventional SOIC and TSOP packages, have short conductive paths between inner leads and pads, low self-inductance, and low wiring resistance within the package.

Due to poor fluidity or non-uniform curing of the epoxy resin composition during the packaging process, the internal gas is not completely exhausted, so that the packaged device absorbs moisture to cause reliability failure, and the generation of the internal gas hole may cause the thermal conductivity to be reduced to cause electrical failure or heat loss. Therefore, it is an endeavor of those skilled in the art to provide a DFN package device with low incidence of internal voids to facilitate heat dissipation.

Disclosure of Invention

The invention aims to provide the DFN packaging device convenient for heat dissipation, which has the advantages of excellent heat dissipation effect and mechanical property, stable and reliable packaging structure and wide application prospect.

In order to achieve the purpose, the invention adopts the technical scheme that: a DFN packaging device convenient for heat dissipation comprises a heat dissipation pad, a chip and a conductive pad, wherein the heat dissipation pad, the chip and the conductive pad are arranged in an epoxy insulator;

a sunken groove for embedding the chip is formed in the central area of the heat dissipation welding disc, so that a cofferdam part is formed at the edge area of the heat dissipation welding disc, silver paste layers are respectively arranged between the bottom of the sunken groove and the cofferdam part as well as the lower surface and the side wall of the chip, a plurality of heat exchange blind holes extending into the heat dissipation welding disc are formed in the bottom of the sunken groove, and silver paste filling parts are arranged in the heat exchange blind holes;

the epoxy insulator comprises the following raw materials in parts by weight: 85 parts of epoxy resin, 50 parts of novolac resin, 18 parts of liquid nitrile rubber, 3 parts of diethyl pyrocarbonate, 65 parts of silicon micropowder, 1.5 parts of polyethylene glycol mono-octyl phenyl ether, 3 parts of 3-aminopropyl triethoxysilane, 2 parts of cellulose acetate butyrate, 0.3 part of 5-fluoro-2-methoxyaniline, 0.5 part of 2,4, 6-tris (dimethylaminomethyl) phenol, 2 parts of a release agent and 25 parts of a flame retardant.

The technical scheme of further improvement in the technical scheme is as follows:

1. in the above scheme, the depth of the sink groove is not greater than the thickness of the chip.

2. In the scheme, the flame retardant is borate and/or molybdate.

3. In the above scheme, the silica fume is fused silica fume.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. according to the DFN packaging device convenient for heat dissipation, the middle part of the heat dissipation welding disc is provided with the sinking groove matched with the chip, so that when the chip is pasted, a worker places silver paste into the sinking groove and installs the corresponding chip into the sinking groove; at this moment, the chip lower part inlays in the heavy groove, not only can its bottom bond with the heavy groove bottom through the silver thick liquid layer that forms, the lateral wall of chip lower part also can pass through silver thick liquid layer with the inner wall of the external cofferdam portion of heavy groove and bond each other, not only the area of contact on chip and silver thick liquid layer increases to some extent, and the area of contact on silver thick liquid layer and heat dissipation pad also increases to make in the unit interval, more heat is between chip and silver thick liquid layer, conduct between silver thick liquid layer and the heat dissipation pad, and then improve DFN encapsulation semiconductor device's radiating effect.

2. According to the DFN packaging device convenient for heat dissipation, the sink groove is arranged in the central area of the heat dissipation welding disc, so that workers can conveniently calibrate the mounting position of a chip, the accurate mounting of the chip is realized, and the packaging quality of the chip is improved; meanwhile, the chip is embedded in the sinking groove, the position of the chip can be positioned, and the arrangement of silver paste is matched to protect the chip and a lead wire connected with the chip, so that the packaging quality is improved; in addition, the heat transfer blind hole is seted up to heavy groove bottom, and setting up of heat transfer blind hole can hold partial silver thick liquid, avoids unnecessary silver thick liquid to spill over heavy groove, treats to have silver thick liquid filling portion in the heat transfer blind hole after, the area of contact of silver thick liquid and heat dissipation dish further increases, and the encapsulation radiating effect obtains further promotion.

3. According to the DFN packaging device convenient for heat dissipation, the liquid nitrile rubber is added into an epoxy resin system in the epoxy insulator formula, 2,4, 6-tri (dimethylaminomethyl) phenol is used as a curing accelerator, and diethyl pyrocarbonate and 5-fluoro-2-methoxyaniline are additionally added, so that the crosslinking density of a cured product is improved, the overall mechanical property of the epoxy insulator is enhanced, and the stability of a packaging structure is effectively ensured.

4. According to the DFN packaging device convenient for heat dissipation, the epoxy insulator adopts epoxy resin and linear phenolic resin, and polyethylene glycol mono-octyl phenyl ether and cellulose acetate butyrate are added, so that the interaction force between a resin system and an inorganic filler is reduced, the fluidity of the composition is obviously improved, the occurrence rate of internal pores after packaging can be effectively reduced, the problem of electric failure caused by reduction of heat conductivity due to the pores is avoided, and the packaging yield is improved.

Drawings

Fig. 1 is a schematic structural diagram of a DFN packaged device convenient for heat dissipation according to the present invention.

In the above drawings: 1. a heat-dissipating pad; 11. sinking a groove; 12. a cofferdam portion; 121. a step portion; 13. heat exchange blind holes; 2. a silver paste layer; 21. a silver paste filling part; 3. a chip; 4. a conductive pad; 5. a lead wire; 6. an epoxy insulator.

Detailed Description

The invention is further described below with reference to the following examples:

example (b): a DFN packaging device convenient for heat dissipation comprises a heat dissipation pad 1, a chip 3 and conductive pads 4, wherein the heat dissipation pad 1, the chip 3 and the conductive pads 4 are positioned in an epoxy insulator 6, the chip 3 is positioned on the heat dissipation pad 1, a plurality of conductive pads 4 are arranged on the periphery of the heat dissipation pad 1, and the conductive pads 4 are connected with the chip 3 through a lead 5;

a sunken groove 11 for embedding the chip 3 is formed in the central area of the heat dissipation pad 1, so that a cofferdam part 12 is formed in the edge area of the heat dissipation pad 1, silver paste layers 2 are respectively arranged between the bottom of the sunken groove 11 and between the cofferdam part 12 and the lower surface and the side wall of the chip 3, a plurality of heat exchange blind holes 13 extending into the heat dissipation pad 1 are formed in the bottom of the sunken groove 11, and silver paste filling parts 21 are arranged in the heat exchange blind holes 13;

the depth of the sinking groove 11 is not more than the thickness of the chip 3;

the raw materials of the epoxy insulator 6 comprise the following components in parts by weight: 85 parts of epoxy resin, 50 parts of novolac resin, 18 parts of liquid nitrile rubber, 3 parts of diethyl pyrocarbonate, 65 parts of silicon micropowder, 1.5 parts of polyethylene glycol mono-octyl phenyl ether, 3 parts of 3-aminopropyl triethoxysilane, 2 parts of cellulose acetate butyrate, 0.3 part of 5-fluoro-2-methoxyaniline, 0.5 part of 2,4, 6-tris (dimethylaminomethyl) phenol, 2 parts of a release agent and 25 parts of a flame retardant.

The fine silica powder is fused fine silica powder, the fine silica powder D50 is 4 to 8 μm, and the fine silica powder D100 is 10 to 25 μm.

The release agent is stearate, and the flame retardant is borate.

The preparation method of the raw material of the epoxy insulator 6 comprises the following steps:

s1, mixing 65-90 parts of silicon micropowder, a flame retardant and 3-aminopropyltriethoxysilane uniformly, and carrying out surface treatment;

s2, adding epoxy resin, novolac resin, liquid nitrile rubber, diethyl pyrocarbonate, polyethylene glycol mono-octyl phenyl ether, cellulose acetate butyrate, 5-fluoro-2-methoxyaniline, 2,4, 6-tri (dimethylaminomethyl) phenol and a release agent, and uniformly mixing;

s3, mixing the mixture at 90-110 ℃ for 3-5 minutes, cooling the product, crushing and sieving.

Comparative examples 1 to 3: the epoxy insulator comprises the following raw materials in parts by weight:

TABLE 1

Components	Comparative example 1	Comparative example 2	Comparative example 3
				Epoxy resin	80	90	100
Phenol novolac resin	50	30	70
				Liquid nitrile rubber	5	18	12
Pyrocarbonic acid diethyl ester	8	-	5
				Silicon micro-meterPowder	65	90	75
Polyethylene glycol Monooctyl phenyl Ether	0.1	1.5	-
				3-aminopropyltriethoxysilane	2	5	4
Cellulose acetate butyrate	-	3	6
				5-fluoro-2-methoxyaniline	2	0.3	-
2,4, 6-tris (dimethylaminomethyl) phenol	0.5	2	5
				Release agent	2	1	5
Flame retardant	10	25	15

The fine silica powder is fused fine silica powder, the fine silica powder D50 is 4 to 8 μm, and the fine silica powder D100 is 10 to 25 μm.

The release agent in comparative example 1 was stearic acid and the flame retardant was borate; the release agent in comparative example 2 was stearate and the flame retardant was borate; the release agent in comparative example 3 was oxidized polyethylene wax and the flame retardant was molybdate.

The preparation process is the same as the embodiment.

The properties of the epoxy insulators prepared in the above examples and comparative examples 1 to 3 are shown in table 2:

TABLE 2

In each of examples and comparative examples, the molding conditions of the epoxy insulator were as follows: the mold temperature is 180 ℃, and the injection pressure is 700kg/cm²Curing time 2 min.

As shown in the evaluation results in table 2, the epoxy insulators in the embodiments have better overall mechanical properties and flowability than the comparative examples, and when used in DFN packaged devices, the stability of the packaging structure can be ensured, the incidence of internal voids after packaging can be reduced, and the packaging yield can be improved.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.