KR20210033599A - A room-temperature fast curing conductive adhesive - Google Patents

Abstract

The present invention relates to a room temperature high-speed curing conductive adhesive mainly comprising: an M-phenyl dimethyl ester epoxy resin; a rosin-modified oil-soluble phenolic resin; polyether; an M-phenyl dimethyl ester epoxy resin curing agent; a curing accelerator; copper powder; and nano silica. The conductive adhesive of the present invention can be cured within 20 minutes at room temperature, can be stored stably at room temperature for 2 months or more, and has shear strength of more than 14 MPa.

Description

Room temperature fast curing conductive adhesive {A ROOM-TEMPERATURE FAST CURING CONDUCTIVE ADHESIVE}

The present invention relates to a room temperature fast curing conductive adhesive belonging to the field of electronic materials, a method of manufacturing the same, and a method of application thereof.

As electronic components and components are becoming more compact and lighter, the conventional Sn/Pb solders used in the microelectronic packaging industry have not been able to meet the process requirements. Therefore, as a novel material, conductive adhesives are widely used in electronic components instead of solder. Conductive adhesives are special adhesives having specific conductive properties after curing and drying; This conductive adhesive is prepared by adding a curing agent, a conductive filler and other additives to the organic polymer matrix resin. The conductive adhesive has a conductive performance close to that of a metal after curing, and can form a conductive loop between the connected materials by connecting the conductive materials with the same or different types, and thus the conductive adhesive is considered an excellent substitute for Sn/Pb solder. The conductive adhesive with copper powder has a conductive performance very similar to that of the conductive adhesive with silver powder, has a relatively good joint strength, and a low production cost, thus attracting great interest. However, current conductive adhesives generally have a problem that the curing time is too long, on the one hand, many applications requiring high-speed curing, such as coating of electroless plated products in which the conductive adhesive must cure completely within minutes or tens of minutes Difficult to satisfy the needs; On the other hand, long curing times will lead to long production cycles that are undesirable for production.

In order to solve the above problems present in the prior art, the present invention provides an M-phenyl dimethyl ester epoxy resin conductive adhesive that can be cured at room temperature at high speed, and a method of manufacturing and applying the same.

The M-phenyl dimethyl ester epoxy resin conductive adhesive of the present invention mainly consists of parts by weight of the following components:

M-phenyl dimethyl ester epoxy resin 100,

Rosin-modified oil-soluble phenolic resin 50-150,

Polyether 2-10,

M-phenyl dimethyl ester epoxy resin curing agent 50-90,

Hardening accelerator 3-6,

Copper powder 200-1600, and

Nano silica 2-4.

M-phenyl dimethyl ester epoxy resin conductive adhesive of the present invention

(1) Weigh the copper powder, add 1% to 3% of a silane coupling agent based on the total weight of the copper powder to obtain a blend, add an appropriate amount of organic solvent to this blend, and ultrasonicate the resultant. Ultrasonically transforming with a grinder for 30 to 40 minutes, pouring the transformed product into an evaporation dish, and performing vacuum drying; And

(2) Add M-phenyl dimethyl ester epoxy resin, M-phenyl dimethyl ester epoxy resin curing agent, curing accelerator, rosin-modified oil-soluble phenolic resin, polyether and nanosilica to the product prepared in step (1) at room temperature. To obtain a mixture, and vacuum stirring the mixture for 30 to 40 minutes to obtain an M-phenyl dimethyl ester epoxy resin conductive adhesive.

In addition, the present invention provides a method of applying the M-phenyl dimethyl ester epoxy resin conductive adhesive, comprising applying the conductive adhesive to the surface of a substrate in an atmospheric environment, and curing the conductive adhesive at room temperature. .

Compared with the conductive adhesive of the prior art, the present invention has the following advantages and advantageous effects:

(1) By exothermic polymerization of rosin-modified oil-soluble phenolic resin and polyether under room temperature in an atmospheric environment, the conductive adhesive of the present invention achieves high-speed curing at room temperature without further heating by a curing time of less than 20 minutes. The conductive adhesive of the present invention has a shear strength higher than 14 MPa, and has excellent heat resistance, weather resistance and moisture resistance; Can be stored at room temperature for at least 2 months without gelation.

(2) By adding a specific ratio of nano-silica to the conductive adhesive, the conductive adhesive of the present invention achieves remarkable reinforcing and toughness effects and achieves high-speed curing while improving the joint strength by 30%.

(3) By surface-treating the copper powder and adjusting its amount within the range described in the present invention, the obtained conductive adhesive has a volume resistivity of less than ^{2x10 -6 Ω·m.}

The invention is described in more detail by the following exemplary embodiments, but the invention is not limited to the specific embodiments described below.

Example 1

500 parts by weight of copper powder was weighed, 10 parts by weight of KH550 dissolved in absolute ethanol was added thereto, and the obtained blend was ultrasonically stirred for 30 minutes, dried in a vacuum dryer and sealed.

In the obtained product containing copper powder, 100 parts by weight of M-phenyl dimethyl ester epoxy resin, 100 parts by weight of rosin-modified oil-soluble phenolic resin, 5 parts by weight of polyether, 60 parts by weight of methylhexahydrophthalic anhydride, 5 parts by weight Parts of MY-24 and 3 parts by weight of nanosilica were continuously added at room temperature under a nitrogen gas atmosphere to obtain a mixture, and the mixture was uniformly mixed and placed in a vacuum drying oven to remove air bubbles, and M-phenyl dimethyl ester epoxy resin conductive adhesive A was obtained.

Example 2

1500 parts by weight of copper powder was weighed, 25 parts by weight of KH550 dissolved in absolute ethanol was added thereto, and the obtained blend was ultrasonically stirred for 30 minutes, dried in a vacuum dryer and sealed.

In the obtained product containing copper powder, 100 parts by weight of M-phenyl dimethyl ester epoxy resin, 130 parts by weight of rosin-modified oil-soluble phenolic resin, 7 parts by weight of polyether, 75 parts by weight of methylhexahydrophthalic anhydride, 4 parts by weight Parts of MY-24 and 2.5 parts by weight of nanosilica were continuously added at room temperature under a nitrogen gas atmosphere to obtain a mixture, and the mixture was uniformly mixed and put in a vacuum drying oven to remove air bubbles, and M-phenyl dimethyl ester epoxy resin conductive adhesive B was obtained.

Example 3

1300 parts by weight of copper powder was weighed, 17 parts by weight of KH550 dissolved in absolute ethanol was added thereto, and the obtained blend was ultrasonically stirred for 30 minutes, dried in a vacuum dryer and sealed.

In the obtained product containing copper powder, 100 parts by weight of M-phenyl dimethyl ester epoxy resin, 125 parts by weight of rosin-modified oil-soluble phenolic resin, 7.5 parts by weight of polyether, 80 parts by weight of methylhexahydrophthalic anhydride, 3 parts by weight Parts of MY-24 and 3.5 parts by weight of nanosilica were continuously added at room temperature under a nitrogen gas atmosphere to obtain a mixture, and the mixture was uniformly mixed and put in a vacuum drying oven to remove air bubbles, and M-phenyl dimethyl ester epoxy resin conductive adhesive C was obtained.

Example 4

800 parts by weight of copper powder was weighed, to which 8 parts by weight of KH550 dissolved in absolute ethanol was added, and the obtained blend was ultrasonically stirred for 30 minutes, dried in a vacuum dryer and sealed.

In the obtained product containing copper powder, 100 parts by weight of M-phenyl dimethyl ester epoxy resin, 90 parts by weight of rosin-modified oil-soluble phenolic resin, 3.5 parts by weight of polyether, 70 parts by weight of methylhexahydrophthalic anhydride, 4 parts by weight Part of MY-24 and 2 parts by weight of nanosilica were continuously added at room temperature under a nitrogen gas atmosphere to obtain a mixture, and the mixture was uniformly mixed and put in a vacuum drying oven to remove air bubbles, and M-phenyl dimethyl ester epoxy resin conductive adhesive D was obtained.

Example 5

1000 parts by weight of copper powder was weighed, 20 parts by weight of KH550 dissolved in absolute ethanol was added thereto, and the obtained blend was ultrasonically stirred for 30 minutes, dried in a vacuum dryer and sealed.

In the obtained product containing copper powder, 100 parts by weight of M-phenyl dimethyl ester epoxy resin, 140 parts by weight of rosin-modified oil-soluble phenolic resin, 9 parts by weight of polyether, 90 parts by weight of methylhexahydrophthalic anhydride, 6 parts by weight Parts of MY-24 and 3 parts by weight of nanosilica were continuously added at room temperature under a nitrogen gas atmosphere to obtain a mixture, and the mixture was uniformly mixed and placed in a vacuum drying oven to remove air bubbles, and M-phenyl dimethyl ester epoxy resin conductive adhesive E was obtained.

Comparative Example 1

M-phenyl dimethyl ester epoxy resin conductive adhesive X was prepared in the same manner as in Example 1, except that low-molecular polyamide was used instead of methylhexahydrophthalic anhydride and the curing accelerator MY-24, and rosin-modified oil-soluble phenolic Resin and polyether were not used.

Comparative Example 2

M-phenyl dimethyl ester epoxy resin conductive adhesive Y was prepared in the same manner as in Example 1, except that nanosilica was not used.

Comparative Example 3

M-phenyl dimethyl ester epoxy resin conductive adhesive Z was prepared in the same manner as in Example 1, except that 5 parts by weight of nanosilica was used.

Test Methods:

(1) Volume resistivity: Tested according to GB/T1410-2006.

(2) Shear strength: The bonded iron sheet for testing according to GB/T 7124-2008 was left in the air and cured at room temperature for 20 minutes.

(3) Storage stability: The obtained conductive adhesive was filled in a 5 ml transparent syringe and stored for 2 months at room temperature, followed by visual inspection for gelation, delamination or precipitation.

(4) Curing time: This is the time period required for the M-phenyl dimethyl ester epoxy resin conductive adhesive to achieve a stable volume resistivity and stable adhesive strength.

The results are presented in Table 1 below:

conductivity
glue Curing time
(min) Volume resistivity
(Ω·m) Shear strength
(MPa) Storage stability
(25℃, 2 months) A 13 1.5x10 ^-6 Ω·m 15.3 No gelation, no delamination or precipitation B 11 1.0x10 ^-6 Ω·m 14.9 No gelation, no delamination or precipitation C 8 1.2x10 ^-6 Ω·m 14.7 No gelation, no delamination or precipitation D 14 1.4x10 ^-6 Ω m 14.1 No gelation, no delamination or precipitation E 4 1.2x10 ^-6 Ω·m 15.6 No gelation, no delamination or precipitation X 700 2.3x10 ^-6 Ω m 13.6 Gelation, precipitation Y 16 1.4x10 ^-6 Ω m 10 No gelation, no delamination or precipitation Z 15 1.7x10 ^-6 Ω m 11.4 No gelation, no delamination or precipitation

As can be seen from Table 1, the conductive adhesive employing the curing system of the present invention can be cured at high speed at room temperature within 15 minutes, and has improved shear strength and improved storage stability compared to the conductive adhesive not employing the curing system of the present invention. ; In addition, compared to the conductive adhesive X-Z, all the conductive adhesives of the present invention were kept at substantially the same level without lowering the volume resistivity.

What has been described above are only embodiments of the present invention, and specific known structures and properties are not described herein. Without departing from the spirit of the present invention, a person of ordinary skill in the art can make many changes and modifications, and all such changes and modifications should be considered to be within the protection scope of the present invention, and do not affect the implementation effect and patent practicability of the present invention. It should be noted that it does not. The scope of protection claimed herein should be based on the content of the claims, and certain embodiments and analogs thereof mentioned herein may be used to describe the content of the claims.

Claims (5)

As a room temperature high-speed curing conductive adhesive mainly composed of parts by weight of the following components,
M-phenyl dimethyl ester epoxy resin 100,
Rosin-modified oil-soluble phenolic resin 50-150,
Polyether 2-10,
M-phenyl dimethyl ester epoxy resin curing agent 50-90,
Hardening accelerator 3-6,
Copper powder 200-1600, and
Nano silica 2-4,
The copper powder is surface-modified by a silane coupling agent, and the conductive adhesive is a room temperature high-speed curing conductive adhesive that can be cured at room temperature within 20 minutes. The method of claim 1,
The M-phenyl dimethyl ester epoxy resin: The M-phenyl dimethyl ester epoxy resin curing agent: The weight ratio of the curing accelerator is in the range of 40-50: 30-40: 1-2 at room temperature high-speed curing conductive adhesive. The method of claim 1,
Room temperature fast curing conductive adhesive that the conductive adhesive can be stably stored at room temperature for 2 months or more. The method of claim 1,
Room temperature high-speed curing conductive adhesive wherein the conductive adhesive has a shear strength of more than 14 MPa. The method of claim 1,
The conductive adhesive has a volume resistivity (volume resistivity) is 2x10 ^{- 6} Ω · m at room temperature under high speed curing conductive adhesive.