RU2662513C1 - Adhesive composition for electronic microwave technology - Google Patents

Abstract

FIELD: electronic equipment.

SUBSTANCE: invention relates to adhesive composition for microwave electronic technology. Composition comprises a binder, modified epoxy resin, reaction product of epoxy silane-silicone resin with tetrabutoxy titanate, with component ratio of 1:0.06, respectively, metal filler is finely-dispersed silver powder, diluent is product of reaction of phenol with epichlorohydrin, hardener. In this case, adhesive composition further comprises spreader – organofenoxysilane, powder of finely dispersed silver of metallic filler is made with dispersion of less than 20 mcm, hardener is made in form of solution of 4,4'-diphenylmethane diisocyanate in butyl acetate or solution of 4,4'-diphenylmethane diisocyanate in dimethylacetamide, in following ratio of components, mass%: binder – modified epoxy resin – product of interaction of epoxy-titanium silicone resin with tetrabutoxy titanate 10.2–11.0; metal filler – finely-dispersed silver powder 68.0–72.0; diluent – product of reaction of phenol with epichlorohydrin 10.6–12.5; hardener – in form of solution of 4,4'-diphenylmethane diisocyanate in butyl acetate 3.2–4.4; spreader – organofenoxysilane 4.0–4.1, or binder-modified epoxy resin-product of interaction of epoxy-titanium silicone resin with tetrabutoxy titanate 11.0–15.0; metal filler – finely-dispersed silver powder 68.0–72.0; diluent – product of reaction of phenol with epichlorohydrin 9.6–11.3; hardener – in form of solution of 4,4'-diphenylmethane diisocyanate in dimethylacetamide 2.7–3.7; spreader – organofenoxysilane 3.0–3.7.

EFFECT: increase in electrical and thermal conductivity, increase in homogeneity of structure and reducing the thickness of adhesive seam, increase in applicability by lowering the curing temperature of adhesive composition, reducing microwave losses.

1 cl, 1 tbl

Description

The invention relates to chemistry and metallurgy, and more particularly to adhesive compositions intended primarily for use in microwave electronic equipment and, above all, electronic solid state microwave technology.

The use of adhesive compositions instead of soldering is today a promising modern technology for connecting individual elements of products of microwave electronics, and in some cases the only possible one.

The main requirements for these adhesive compositions are to provide both high technical characteristics - high electrical and thermal conductivity, high mechanical strength of the elements of products of microwave electronic equipment, and their manufacturability.

The indicated requirements today are most met by electrical and heat-conducting adhesive compositions (hereinafter referred to as adhesive composition) based on a modified epoxy resin.

Known adhesive composition containing a binder based on a modified epoxy resin and its diluent, hardener and metal filler is silver powder, in which, in order to increase electrical and heat conductivity, heat resistance and processability, reduce viscosity, while maintaining high cohesive strength of the conductive adhesive composition and correspondingly high mechanical strength of the adhesive joint, the binder is an epoxynolac resin, and its diluent is diglycidyl ether, the hardener is the product the interaction of aminophenol with unsaturated organic acids, a metal filler is a powder of nanodispersed silver, while the adhesive composition additionally contains a mixture of a sizing additive and a spreading agent at a ratio of 1: 1, respectively, which is a mixture of organophenoxysiloxane and organophenoxysilane, and a solvent from the group of ethers of polyglycols in the following ratio components, wt. hours:

epoxy resin 2.2-1.4 diglycidyl ether 0.7-0.3 aminophenol reaction product with unsaturated organic acids 2.9-1.7 nanodispersed silver powder 72.0-82.0 a mixture of organophenoxysiloxane and organophenoxysilane with their ratio 1: 1, respectively 2.2-2.6 polyglycol ethers solvent rest

[RF patent 2412972. Conductive adhesive composition / Ershova T.N. et al. // Bull. - 2011 - No. 27].

The presence in the adhesive composition as a binder epoxy resin, due to its increased chemical activity (the presence of an increased number of active functional epoxy groups) and in combination with the proposed diluent, provides the adhesive composition:

on the one hand, the highest possible high content of the amount of metal filler with the lowest possible low content of the amount of binder and, accordingly, its extremely high bulk density relative to the bulk density of the binder, due to the use of the metal filler in the form of nanodispersed silver;

and on the other hand, maintaining a high cohesive and adhesive strength of the adhesive composition.

And, as a result, a significant increase in electrical and thermal conductivity while maintaining the mechanical strength of the adhesive joint.

The disadvantages of this adhesive composition are:

low productivity due to the length of time the preparation of the adhesive composition (9 hours) due to the high specific surface of the metal filler with its high content (72-82) wt. hours, respectively, requiring a longer time to ensure its full wettability;

limited application due to the high curing temperature of the adhesive (175 ° C).

This high-temperature mode is not suitable for a number of products of microwave electronic solid-state technology.

Known adhesive composition containing a modified epoxidian resin and hardener.

Which, with the aim of creating a high-tech heat-resistant adhesive composition having a low working viscosity, long viability at normal temperature, high mechanical strength and a long working resource in a wide temperature range, contains, as a modified epoxy resin, the product of the interaction of organosilicon resin with tetrabutoxy titanate with a ratio of 1: 0.06, respectively, and as a hardener - 4,4'-diphenylmethanediisocyanate, substituted dimethylamino m, with a ratio of components, wt. hours:

Modified epoxy resin 93.0-90.0;

Hardener 7.0-10.0

[RF patent 2238294. Heat-resistant adhesive composition / Ershova T.N. et al. // Bull. - 2004 - No. 29 /].

Known electro-and heat-conducting adhesive composition containing a binder - epoxy resin, a hardener and a metal filler, which, with the aim of high-strength contact connection of the elements of the electronic solid-state microwave technology - integrated and hybrid integrated circuits, while reducing the duration of installation operations and ensuring waste-free technology using precious metal, as the epoxy resin contains the product of the interaction of epoxytitanium silicone resin with tetrabutoxytitanate , with a component ratio of 1: 0.06, respectively, as a hardener - 4,4'-diphenylmethanediisocyanate substituted with dimethylamine, as a metal filler - fine silver powder, and additionally contains a diluent - the product of the interaction of phenol with epichlorohydrin, in the following ratio of components, wt. %:

binder - a product of interaction  epoxy titanium silicone resin with tetrabutoxy titanate in the ratio components 1: 0.06, respectively  13.5-24.3 hardener - 4,4'-diphenylmethanediisocyanate, dimethylamine substituted  1.5-2.7 metal filler - powder fine silver  70.0-80.0 the above diluent  3.0-5.0

[RF patent 2246519. Conductive adhesive composition / Ershova T.N. et al. // Bull. - 2005.20.02 /].

This electro- and heat-conducting adhesive composition (primarily of the prototype) due to the use of chemical affinity of the product of the interaction of organosilicon resin and tetrabutoxy titanate with a ratio of 1: 0.06, respectively (binder) and low viscosity (dynamic viscosity less than 0.09 Pa × s) of the condensation product phenol with epichlorohydrin (diluent), 4,4'-diphenylmethanediisocyanate substituted with dimethylamine (hardener), ensures the presence in the bulk mass of the adhesive composition of a large number high-strength heat-resistant chemical bonds such as -C-Si-C-, -C-Ti-C-, heat-resistant cyclic structures (phenyl units), active functional groups (epoxy, amine, hydroxyl) and during the chemical interaction between these components and subsequent curing adhesive composition under conditions of a short-term heat pulse provides the formation of high-strength spatial structures of the adhesive joint with finely dispersed silver particles evenly distributed in it.

However, this adhesive composition has several disadvantages, namely:

firstly, a metal filler - fine silver powder has a dispersion of up to 50 microns,

secondly, the hardener is crystalline.

This does not allow for the thickness of the adhesive joint less than 20 microns, which in turn determines the loss of microwave when used in microwave electronic products.

In addition, the second - increases the time and temperature of curing of the adhesive composition, the latter - limits its applicability, and especially in the electronic solid state microwave technology.

The technical result of the claimed adhesive composition for microwave electronics is to increase electrical and heat conductivity, increase the uniformity of the structure and decrease the thickness of the adhesive joint, expand applicability by lowering the curing temperature of the adhesive composition, and reduce losses of microwave elements of microwave electronic equipment (hereinafter referred to as microwave losses).

The specified technical result is achieved by the claimed adhesive composition for microwave electronic equipment containing a binder - a modified epoxy resin - the reaction product of an epoxytitanium-silicone resin with tetrabutoxy titanate, with a component ratio of 1: 0.06, respectively, a metal filler is a fine silver powder, a diluent is a product of the interaction of phenol with epichlorohydrin hardener.

Wherein

the adhesive composition further comprises a spreading agent - organophenoxysilane,

fine powder of silver metal filler made dispersion less than 20 microns,

the hardener is made in the form of a solution of 4,4'-diphenylmethanediisocyanate in butyl acetate,

or a solution of 4,4'-diphenylmethanediisocyanate in dimethylacetamide, in the following ratio, wt. %:

binder - modified epoxy resin is a reaction product epoxy titanium silicone resin with tetrabutoxy titanate  10.2-11.0 metal filler - powder fine silver  68.0-72.0 diluent is a product of interaction phenol with epichlorohydrin  10.6-12.5 hardener - in the form of a solution 4,4'-diphenylmethanediisocyanate in butyl acetate,  3.2-4.4 spreading agent - organophenoxysilane  4.0-4.1 or  binder - modified epoxy  resin is a reaction product epoxy titanium silicone resin  with tetrabutoxy titanate  11.0-15.0 metal filler - powder fine silver  68.0-72.0 diluent is a product of interaction phenol with epichlorohydrin  9.6-11.3 hardener - in the form of a solution 4,4'-diphenylmethane-diisocyanate in dimethylacetamide,  2.7-3.7 spreading agent - organophenoxysilane  3.0-3.7

Disclosure of the invention

The essential features of the claimed adhesive composition for microwave electronic equipment, proposed - different qualitative, different quantitative compositions of the components and additional functional additives, provide both individually and in combination, namely:

the presence in the adhesive composition of an additional spreading agent - organophenoxysilane - improves the wettability of the particles of the metal filler - fine silver powder, and thereby improves the wettability of the glued surfaces of the elements and, as a result, increases the uniformity of the structure and reduces the thickness of the adhesive joint when gluing elements of microwave electronic equipment before total elements of electronic solid state microwave technology.

The implementation of a fine powder of silver metal filler with a particle size of less than 20 microns provides an adhesive joint thickness of less than 20 microns and, as a result, reduces microwave losses.

The implementation of the hardener in the form of a solution of 4,4'-diphenylmethanediisocyanate in dimethylacetamide or a solution of 4,4'-diphenylmethanediisocyanate in butyl acetate ensures the transfer of the crystalline hardener to the liquid phase and thereby

firstly, the exclusion of the influence of the size of the hardener crystals on the homogeneity of the structure and the thickness of the adhesive joint,

secondly, a decrease in the working viscosity of the adhesive composition,

thirdly, lowering the curing temperature of the adhesive composition to less than 120 ° C.

And as a consequence,

- increasing the electrical and thermal conductivity of the adhesive composition,

- increasing the uniformity of the structure and reducing the thickness of the adhesive joint,

- extension of applicability,

- reduction of microwave losses.

The indicated quantitative ratio of the components of the adhesive composition, wt. % are optimal both for each component of the adhesive composition, and for the entire adhesive composition as a whole, which provide:

- increasing the electrical and thermal conductivity of the adhesive composition,

- increasing the uniformity of the structure and reducing the thickness of the adhesive joint,

- expanding applicability by reducing the curing temperature of the adhesive composition to less than 120 ° C,

- reduction of microwave losses.

Thus, the claimed adhesive composition fully provides the claimed technical result, namely, increasing electrical and thermal conductivity, increasing the uniformity of the structure and reducing the thickness of the adhesive joint, expanding applicability, and especially in electronic solid-state microwave technology.

When using other components and when the above-mentioned optimal quantitative ratios of the components go beyond the limits indicated in the claims, there is a violation of the above technical and technological advantages that provide the claimed technical result, namely:

the amount of binder as less than 10.2 and more than 11.0 wt. % undesirable, in the first case due to the deterioration of the wettability of the metal filler, in the second - violation of the optimal quantitative ratio of the binder and filler;

the amount of metal filler as less than 68.0, and more than 72.0 wt. % is not permissible, as it leads to a decrease in electrical and thermal conductivity;

the amount of diluent is less than 10.6 wt. % is unacceptable due to an increase in working viscosity and, accordingly, a decrease in electrical and thermal conductivity, and more than 12.5 wt. % undesirable due to violation of the optimal quantitative ratio of the binder and the metal filler;

the amount of hardener as less than 3.2, and more than 4.4 wt. % undesirable due to a violation in the process of a chemical reaction of curing the optimal quantitative ratio of the binder and hardener;

the amount of spreading agent as less than 4.0 or 3.0, and more than 4.1 or 3.7 wt. % undesirable due to deterioration in the wettability of glued surfaces.

Examples of specific performance of the claimed electro- and heat-conducting adhesive composition are considered for connecting the elements of a solid-state electronic equipment microwave - Submodule microwave KRPG.434857.015 SB (hereinafter products).

Example 1

The starting components are prepared, for which they are weighed:

a binder - a modified epoxy resin - the product of the interaction of epoxytitanium silicone resin with tetrabutoxy titanate with a ratio of components of 1: 0.06, respectively, of the brand SEDM-8 TU 2531-059-174111121-2015 in an amount of 10.6 wt. % (item 1);

metal filler - fine powder of PS-1 grade TU 1752-001-59839838-2003 in the amount of 70.0 wt. %, provide it with a dispersion of up to 20 microns (item 2);

diluent - the product of the interaction of phenol with epichlorohydrin - EPH TU 2225-510-00203521-1994 in an amount of 11.5 wt. % (item 3);

the spreading agent is organofenoxysilane of the Penta-75 brand TU 2437-242-40245042-2009 in an amount of 4.05 wt. % (item 4).

A hardener is prepared - in the form of a solution of 4,4'-diphenylmethanediisocyanate TU 2494-480-04872688-2006 in butyl acetate of the grade “GC” GOST 22300-76 in a total amount of 3.8 wt. % (item 5).

Then mix:

a binder - a modified epoxy resin - the product of the interaction of epoxytitanium silicone resin with tetrabutoxytitanate in the amount of 10.6 wt. % (item 1);

hardener - in the form of a solution of 4,4'-diphenylmethanediisocyanate TU 2494-480-04872688-2006 in butyl acetate in a total amount of 3.8 wt. % (item 5) and mix thoroughly.

Next, in this mixture in direct sequence add:

metal filler - fine silver powder in an amount of 70.0 wt. % (item 2);

the spreading agent is organophenoxysilane in an amount of 4.05, wt. % (item 4);

diluent - the product of the interaction of phenol with epichlorohydrin in an amount of 11.5 wt. % (item 3).

Next, everything is thoroughly mixed until a homogeneous mass.

Examples 2-7

Analogously to example 1, samples of the adhesive composition were prepared, but each having a different quantitative and qualitative content of the starting components, as indicated in the claims (examples 2-3 and 4-6), while two particular cases of its execution, when the hardener is in the form of a solution 4,4'-diphenylmethanediisocyanate in dimethylacetamide or a solution of 4,4'-diphenylmethanediisocyanate in butyl acetate, respectively.

Example 7 corresponds to the prototype.

The fabricated samples of the conductive adhesive composition were used to connect the elements of the product of the microwave solid-state electronic equipment - Submodule microwave KRPG.434857.015 SB.

Why, using a special needle, they take drops from the container of the claimed adhesive composition made from the container and place each of them under the microscope on the topology of the contact pads (the place of each necessary connection) of the elements of each product.

Then, the product elements are placed on these drops of the adhesive composition and slightly squeezed by their mounting stick.

Then the products are placed in an oven and the adhesive composition is cured at a temperature of 100 ° C for 4 hours. The curing mode is single-stage.

On the specified samples of the product were

measured:

- electrical conductivity, Ohm × cm - according to the KRPG method.25803.00024;

- thermal conductivity, W / m × K - according to the method of TV-04/08;

defined:

- uniformity of the structure of the glue line using the MBS-1 microscope;

- thickness of the adhesive joint by means of a K-7 thickness gauge.

The data are summarized in the table.

As can be seen from the table, the samples of the adhesive composition, the qualitative and quantitative content of the components of which are made according to the claimed claims (examples 1-3, 4-6) are two variants of the adhesive composition and, accordingly, the products have:

- electrical conductivity, Ohm * cm - (0.77, 0.98, 0.5) * 10 ^-3 or (0.75, 1.02 0.55) × 10 ^-3 examples (1-3 and 4-6 ) respectively;

- thermal conductivity, W / m × K - (19.8, 18.8 25.0) or (19.5, 18.5 25.0) (examples 1-3 and 4-6), respectively;

- homogeneity of the structure (0.1-20.0) / μm ² (examples 1-6);

- thickness of the adhesive joint (12.0, 17.5 7.0) or (12.5 18.0, 8.0) microns,

in contrast to the samples of the adhesive composition of the prototype, which has:

- electrical conductivity 5.0 × 10 ^-3 Ohm × cm;

- thermal conductivity 6.0 W / m × K;

- uniformity of the structure of the adhesive joint (20.0-50.0) / μm.

- thickness of the adhesive joint 50.0 μm.

Data on microwave losses are not presented due to their relatively small size, due to the extremely small thickness of the adhesive joint (less than 20 microns).

Thus, the claimed electro-and heat-conducting adhesive composition will provide in comparison with the prototype

increase:

- electrical conductivity, Ohm × cm - about 5 times;

- thermal conductivity, W / m × K - about 4 times;

- uniformity of the structure of the adhesive joint about 2 times,

decrease:

- thickness of the adhesive joint about 2.5 times,

- microwave losses.

Expanding applicability by reducing the curing temperature of the adhesive composition by about 20 ° C.

The claimed adhesive composition with the indicated technical characteristics is extremely relevant for microwave electronic equipment and other areas of technology.

Claims (8)

An adhesive composition for microwave electronics containing a binder - a modified epoxy resin - the product of the interaction of an epoxytitanium-silicone resin with tetrabutoxytitanate, with a component ratio of 1: 0.06, respectively, a metal filler is a fine silver powder, a diluent is a product of the interaction of phenol with epichlorohydrin, a hardener, characterized in , what the adhesive composition further comprises a spreading agent - organophenoxysilane, fine powder of silver metal filler made dispersion less than 20 microns, the hardener is made in the form of a solution of 4,4'-diphenylmethanediisocyanate in butyl acetate, or a solution of 4,4'-diphenylmethanediisocyanate in dimethylacetamide, in the following ratio, wt. %: binder - modified epoxy resin is a reaction product  epoxy titanium silicone resin with tetrabutoxy titanate  10.2-11.0 metal filler - powder fine silver  68.0-72.0 diluent is a product of phenol interaction  with epichlorohydrin  10.6-12.5 hardener - in the form of a solution 4,4'-diphenylmethanediisocyanate in butyl acetate,  3.2-4.4 spreading agent - organophenoxysilane  4.0-4.1 or binder - modified epoxy  resin is a reaction product epoxy titanium silicone resin with tetrabutoxy titanate  11.0-15.0 metal filler - powder fine silver  68.0-72.0 diluent - a product of the interaction of phenol with epichlorohydrin  9.6-11.3 hardener - in the form of a solution 4,4'-diphenylmethanediisocyanate in dimethylacetamide,  2.7-3.7 spreading agent - organophenoxysilane   3.0-3.7