Composition, Low Halogen and Fast Curing Conductive Adhesive and Its Preparation Method

Abstract

The present invention refers to a composition, a low halogen and fast curing conductive adhesive and its preparation method. The composition includes the following raw materials measured by weight: epoxy resin 5-15 parts, curing agent 0.5-3 parts, acrylic acid component 5-12 parts, initiator 0.5-2 parts, flexibilizer2-5 parts, wetting dispersant 0.1-1 parts, coupling agent 0.1-1 parts, antioxidant 0.1-1 parts, defoamer 0.1-1 parts and conductive silver filler 75-85 parts. The low halogen and fast curing conductive adhesive of the present invention has the advantages of fast curing (within 10 min), low halogen content, high bond strength, good moisture-heat aging resistance, good electric conductivity and thermal conductivity and so on, and has wide application prospects in the field of microelectronic packaging.

Claims

1. A composition for preparing a low halogen and fast curing conductive adhesive, characterized in that, it includes the following raw materials measured by weight: epoxy resin 5-15 parts, curing agent 0.5-3 parts, acrylic acid component 5-12 parts, initiator 0.5-2 parts, flexibilizer 2-5 parts, wetting dispersant 0.1-1 parts, coupling agent 0.1-1 parts, antioxidant 0.1-1 parts, defoamer 0.1-1 parts and conductive silver filler 75-85 parts; the epoxy resin is at least one selected from electronic grade low halogen bisphenol-A epoxy resin, bisphenol-F epoxy resin, dicyclopentadienol epoxy resin and naphthol epoxy resin; the acrylic acid component is acrylic monomers with a molecular weight of 100 to 400 and a hydrophobic structure; the flexibilizer is electronic grade bisphenol-F epoxy resin modified by nano silica or core-shell structural rubber particles.

2. The composition of claim 1, characterized in that, the acrylic monomers are at least one selected from benzyl phenoxyel acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, dicyclopentadienol acrylate, trimethylolpropanetriacrylate, methyl methacrylate, cyclohexyl methacrylate, isobornyl 2-methyl-2-propenoate, benzyl methacrylate, glycidyl methacrylate, trihydroxymethylcyclohexyl methacrylate and trimethylolpropanetrimethacrylate.

3. The composition of claim 1, characterized in that, the curing agent is at least one selected from 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole and 1-cyanoethyl-2-undecylimidazole.

4. The composition of claim 1, characterized in that, the initiator is at least one selected from tert-butyl peroxybenzoate, tert-butyl peroxyacetate, benzoyl peroxide and tert-butyl peroxy-2-ethylhexanoate.

5. The composition of claim 1, characterized in that, the conductive silver filler consists of flaky silver powders with an average diameter of 1 μm to 20 μm, near spherical silver powders with an average particle size of 0.2 μm to 5 μm, and nanometer silver powders with an average particle size of 20 nm to 50 nm.

6. The composition of claim 5, characterized in that, the mass ratio of the flaky silver powders, the near spherical silver powders and the nanometer silver powders is 60-90:10-30:1-5.

7. The composition of claim 5, characterized in that, the average diameter of the flaky silver powders is 1 μm to 15 μm.

8. The composition of claim 5, characterized in that, the average particle size of the near spherical silver powders is 1 μm to 3 μm.

9. A preparation method of a low halogen and fast curing conductive adhesive using the composition of claim 1, characterized in that, it includes the following steps: (1) putting epoxy resin, curing agent, acrylic acid component, initiator, flexibilizer, wetting dispersant, coupling agent, antioxidant and defoamer into a blender to disperse to obtain a liquid mixture; (2) adding conductive silver filler into the liquid mixture, dispersing in a blender, and then defoaming to obtain the low halogen and fast curing conductive adhesive.

10. The preparation method of claim 9, characterized in that, in step (1), the dispersing lasts for 1 min to 3 min.

11. The preparation method of claim 9, characterized in that, in step (1), the blender is in a mode of revolution and rotation synchronous agitation.

12. The preparation method of claim 9, characterized in that, in step (2), the dispersing lasts for 1 min to 3 min.

13. The preparation method of claim 9, characterized in that, in step (2), the defoaming lasts for 30 min to 60 min.

14. The preparation method of claim 9, characterized in that, in step (2), the defoaming is under the condition of −0.1 MPa.

15. The preparation method of claim 9, characterized in that, in step (2), the blender is in a mode of revolution and rotation synchronous agitation.

16. A low halogen and fast curing conductive adhesive prepared by the preparation method of claim 9.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The technical solutions of the present invention will be clearly and completely described in combination with the embodiments of the present invention.

[0044] The parts in the following examples is measured by weight.

EXAMPLE 1

[0045] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 2 min: 2 parts of electronic grade bisphenol-A epoxy resin 328 (Huayi, Shanghai), 2 parts of naphthol epoxy resin HP-4032 (DIC Corporation, Japan), 3 parts of electronic grade bisphenol-F epoxy resin 370 (Huayi, Shanghai), 0.6 parts of curing agent 1-cyanoethyl-2-methylimidazole, 4 parts of isobornyl acrylate, 3 parts of glycidyl methacrylate, 0.6 parts of tert-butyl peroxybenzoate, 2 parts of flexibilizer MX139 (KANEKA, Japan), 0.2 parts of wetting dispersant VATIX 2017 (Vatix, Beijing), 0.2 parts of coupling agent SCA-E87M (NANJING CAPATUE CHEMICAL CO., LTD), 0.2 parts of antioxidant RIANOX 1010 (Rianlon, Tianjin), 0.2 parts of defoamer VATIX 1030 (Vatix, Beijing). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 2 min: 60 parts of flaky silver powders (with an average diameter of 5 μm), 20 parts of near spherical silver powders (with an average particle size of 0.6 μm) and 2 parts of nanometer silver powders (with an average particle size of 35 nm). The obtained mixture was defoamed for 30 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 10 min at 170° C.

EXAMPLE 2

[0046] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 2 min: 2 parts of electronic grade bisphenol-A epoxy resin NPEL-127E (Nanya, Taiwan), 3 parts of naphthol epoxy resin HP-4032 (DIC Corporation, Japan), 3 parts of electronic grade bisphenol-F epoxy resin JE-8672 (Jiadida, Shenzhen), 0.8 parts of curing agent 1-benzyl-2-methylimidazole, 4 parts of trihydroxymethylcyclohexyl methacrylate, 4 parts of glycidyl methacrylate, 0.8 parts of tert-butyl peroxyacetate, 2 parts of flexibilizer MX139 (KANEKA, Japan), 0.1 parts of wetting dispersant BYK-W969 (BYK, Germany), 0.1 parts of coupling agent SCA-E87E (NANJING CAPATUE CHEMICAL CO., LTD), 0.1 parts of antioxidant RIANOX 3114 (Rianlon, Tianjin), 0.1 parts of defoamer BYK-A530 (BYK, Germany). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 3 min: 65 parts of flaky silver powders (with an average diameter of 12 μm), 12 parts of near spherical silver powders (with an average particle size of 1.5 μm) and 3 parts of nanometer silver powders (with an average particle size of 30 nm). The obtained mixture was defoamed for 40 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 5 min at 175° C.

EXAMPLE 3

[0047] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 2 min: 2 parts of electronic grade bisphenol-A epoxy resin 328 (Huayi, Shanghai), 2 parts of dicyclopentadienol epoxy resin HP-7200 (DIC Corporation, Japan), electronic grade bisphenol-F epoxy resin JE-8672 (Jiadida, Shenzhen), 0.8 parts of curing agent 1-cyanoethyl-2-methylimidazole, 2 parts of dicyclopentadienol acrylate, 2 parts of isobornyl 2-methyl-2-propenoate, 3 parts of glycidyl methacrylate, 0.8 parts of tert-butyl peroxybenzoate, 3 parts of flexibilizer NANOPDX E500 (EVONIK, Germany), 0.1 parts of wetting dispersant VATIX 2018 (Vatix, Beijing), 0.1 parts of coupling agent Silok 6634E (Silok, Guangzhou), 0.1 parts of antioxidant RIANOX 245 (Rianlon, Tianjin), 0.1 parts of defoamer BYK-320 (BYK, Germany). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 2 min: 70 parts of flaky silver powders (with an average diameter of 8 μm), 10 parts of near spherical silver powders (with an average particle size of 1.4 μm) and 1 part of nanometer silver powders (with an average particle size of 40 nm). The obtained mixture was defoamed for 50 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 8 min at 170° C.

EXAMPLE 4

[0048] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 1 min: 3 parts of dicyclopentadienol epoxy resin HP-7200 (DIC Corporation, Japan), 5 parts of electronic grade bisphenol-F epoxy resin JE-8672 (Jiadida, Shenzhen), 1 part of curing agent 2-ethyl-4-methylimidazole, 6 parts of dicyclopentadienol acrylate, 5 parts of glycidyl methacrylate, 0.6 part of benzoyl peroxide, 1 part of flexibilizer NANOPDX E500 (EVONIK, Germany), 0.1 parts of wetting dispersant BYK-W969 (BYK, Germany), 0.1 parts of coupling agent Silok 6634E (Silok, Guangzhou), 0.1 parts of antioxidant RIANOX 1076 (Rianlon, Tianjin), 0.1 parts of defoamer BYK-320 (BYK, Germany). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 2 min: 64 parts of flaky silver powders (with an average diameter of 3 μm), 12 parts of near spherical silver powders (with an average particle size of 0.4 μm) and 2 parts of nanometer silver powders (with an average particle size of 25 nm). The obtained mixture was defoamed for 40 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 8 min at 175° C.

EXAMPLE 5

[0049] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 1 min: 6 parts of naphthol epoxy resin HP-4032 (DIC Corporation, Japan), 8 parts of electronic grade bisphenol-F epoxy resin 370 (Huayi, Shanghai), 1 part of curing agent 2-undecylimidazole, 3 parts of benzyl methacrylate, 2 parts of glycidyl methacrylate, 0.6 parts of tert-butyl peroxyacetate, 2 parts of flexibilizer MX139 (KANEKA, Japan), 0.1 parts of wetting dispersant VATIX 2017 (Vatix, Beijing), 0.1 parts of coupling agent SCA-E87M (NANJING CAPATUE CHEMICAL CO., LTD), 0.1 parts of antioxidant RIANOX 3114 (Rianlon, Tianjin), 0.1 parts of defoamer BYK-A530 (BYK, Germany). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 2 min: 60 parts of flaky silver powders (with an average diameter of 18 μm), 15 parts of near spherical silver powders (with an average particle size of 1.8 μm) and 2 parts of nanometer silver powders (with an average particle size of 45 nm). The obtained mixture was defoamed for 60 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 5 min at 175° C.

EXAMPLE 6

[0050] The following components were accurately weight and put into a blender using the revolution and rotation synchronous agitation mode to mix for 2 min: 10 electronic grade bisphenol-F epoxy resin JE-8672 (Jiadida, Shenzhen), 1 part of curing agent 1-cyanoethyl-2-methylimidazole, 4 parts of isobornyl acrylate, 4 parts of glycidyl methacrylate, 0.6 parts of tert-butyl peroxybenzoate, 3 parts of flexibilizer MX139 (KANEKA, Japan), 0.1 parts of wetting dispersant VATIX 2018 (Vatix, Beijing), 0.1 parts of coupling agent SCA-E87E (NANJING CAPATUE CHEMICAL CO., LTD), 0.1 parts of antioxidant RIANOX 245 (Rianlon, Tianjin), 0.1 parts of defoamer BYK-A530 (BYK, Germany). Then the following components were added to the above obtained liquid mixture and put into a blender using the revolution and rotation synchronous agitation mode to disperse for 2 min: 65 parts of flaky silver powders (with an average diameter of 15 μm), 10 parts of near spherical silver powders (with an average particle size of 1.5 μm) and 2 parts of nanometer silver powders (with an average particle size of 35 nm). The obtained mixture was defoamed for 60 min under the condition of −0.1 MPa to obtain the low halogen and fast curing conductive adhesive. The curing condition of this low halogen and fast curing conductive adhesive is 6 min at 175° C.

[0051] Test 1 Halogen Content Test

[0052] The chlorine content and bromine content of the samples obtained by the above examples were measured using X fluorescence spectrometer based on EN 14582:2007 test standard.

[0053] Test 2 Viscosity Test

[0054] The viscosity of the samples obtained by the above examples were measured using rotary viscometer at room temperature.

[0055] Test 3 Volume Resistivity Test

[0056] The volume resistivity of the samples obtained by the above examples were measured based on the four probe method and ASTM D257-2007 test standard.

[0057] Test 4 Thermal Conductivity

[0058] The thermal conductivity of the samples obtained by the above examples were measured using a laser thermal conductivity instrument and based on ASTM E1461-07 test standard.

[0059] Test 5 Shear Strength Test

[0060] The shear strength of the samples obtained by the above examples were measured using a universal mechanical testing machine and based on ASTM D1002 test standard.

[0061] Test 6 Moisture-Heat Aging Resistance (M-H Aging Resistance)

[0062] The moisture-heat aging resistance of the samples obtained by the above examples were measured under the condition of 85° C. and 85% humidity under GB2423.03 test standard.

[0063] The results of the above tests are shown in Table 1 below.

TABLE-US-00001 TABLE 1 test results of examples 1-6 Viscosity Halogen Decline of after Curing (chlorine) Volume Thermal Shear M-H aging mixing time content resistivity conductivity strength resistance (mPa .Math. S) (min) (ppm) (10.sup.−4Ω .Math. cm) (W/m .Math. K) (MPa) (%) Example 1 8180 10 90 2.6 3.4 16  7% Example 2 8250 5 76 4.2 2.8 17  8% Example 3 8050 8 65 1.3 3.9 20  4% Example 4 7980 8 85 7.8 2.3 21  6% Example 5 8140 5 68 9.5 2.1 19  7% Example 6 7560 6 82 8.5 2.0 19 13%

[0064] The above description is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and the like within the spirit and principle of the present invention shall be included in the protection scope of the present invention.