TWI699412B - Paste composition, semiconductor device and electrical and electronic parts - Google Patents

Abstract

The present invention provides a paste composition that has high thermal conductivity, excellent heat dissipation, and enables semiconductor elements and light-emitting elements to be bonded to a substrate well without pressure.

The present invention is a paste composition, a semiconductor device that uses the paste composition as a die bonding paste, and an electrical and electronic component that uses the paste composition as an adhesive material for a heat dissipation member. The above-mentioned paste composition The material contains: (A) copper microparticles with a thickness or short diameter of 10 to 500 nm, and (B) a sintering aid containing an acid anhydride structure, and relative to 100 parts by mass of (A) copper microparticles, (B) sintering aid blending 0.01~1 parts by mass.

Description

Paste composition, semiconductor device and electrical and electronic parts

This embodiment relates to a paste composition and semiconductor devices and electrical and electronic components manufactured using the paste composition.

With the large-capacity, high-speed processing, and fine wiring of semiconductor products, the treatment of heat generated during the operation of semiconductor products, so-called thermal management, has attracted attention.

Therefore, a method of installing heat spreaders or heat sinks and other heat dissipating components in semiconductor products is generally adopted, and it is expected that the material of the heat dissipating component itself has a higher thermal conductivity.

In addition, in order to make the heat management more efficient, according to the form of the semiconductor product, a method of attaching the heat sink to the semiconductor element itself or the die base of the lead frame of the semiconductor element is used, or by exposing the die base to the package A method of making the surface of the body function as a heat sink (for example, refer to Patent Document 1).

Furthermore, there are also cases where semiconductor devices are attached to organic substrates with heat dissipation mechanisms such as thermal vias. In this case, high thermal conductivity is also required for the material adhering to the semiconductor device. In addition, in recent years, white light-emitting LEDs (Light Emitting Diodes) have been widely used in lighting devices such as backlights, ceiling lamps, or downlights for full-color LCD screens due to higher brightness. Of course However, due to the high current on caused by the higher output of the light-emitting element, there is a concern that the adhesive between the light-emitting element and the substrate may be discolored due to heat, light, etc., or the resistance value may change over time. In particular, the method of making the bonding between the semiconductor element and the lead frame completely rely on the adhesive force of the adhesive has the following concerns: when the solder is installed in electronic parts or electronic equipment, the bonding material loses the adhesive force at the melting temperature of the solder and peels off, resulting in failure Lights up. In addition, the higher performance of the white light emitting LED will cause the heat dissipation of the light emitting element chip to increase, and accordingly, the structure of the LED and the components used for it also require an improvement in heat dissipation.

Especially in recent years, power semiconductor devices using wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride, which have less power loss, have been popularly developed. The device itself has high heat resistance and can be operated at a temperature of 250°C or higher with a large current. The high temperature action. However, in order to take advantage of this characteristic, it is necessary to efficiently dissipate heat generated during operation, and a bonding material that is excellent in long-term high temperature heat resistance in addition to electrical conductivity and heat transfer is required.

As mentioned above, high thermal conductivity is required for the bonding material (die bonding paste, or heat dissipation member bonding material, etc.) used in the bonding of each component of semiconductor devices and electrical and electronic equipment. In addition, these materials also need to withstand the reflow process when the product is mounted on the substrate. Furthermore, there are many cases where large-area bonding is required, and it is also necessary to reduce the difference in thermal expansion coefficients between the components. Low stress caused by warpage.

Here, in order to obtain an adhesive with high thermal conductivity, metal fillers such as silver powder and copper powder, or ceramic fillers such as aluminum nitride and boron nitride are usually dispersed in the organic system as fillers at a high content rate. In the adhesive (for example, refer to Patent Document 2). However, as a result, with hardening The increase in the modulus of elasticity of the object may make it difficult to balance thermal conductivity and reflowability (not easy to peel off after the above reflow treatment).

However, recently, as a candidate for a bonding method that can withstand such requirements, a bonding method using silver nanoparticles that can be bonded at a lower temperature than bulk silver has been focused (for example, refer to Patent Document 3).

However, the conductivity of silver particles is very good, but due to the high price and the possibility of migration, research is underway to replace them with other metals. Therefore, copper particles, which are more economical than silver particles and have anti-migration properties, are currently attracting attention.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2006-086273

[Patent Document 2] Japanese Patent Laid-Open No. 2005-113059

[Patent Document 3] Japanese Patent Laid-Open No. 2011-240406

However, at the time of bonding by sintering of copper nanoparticles, a high temperature of 300°C is required to exhibit electrical conductivity. Furthermore, copper nanoparticles have a small particle size and are easily oxidized. Therefore, there are situations where it takes time to operate or process. Furthermore, in the sintering of copper particles, it is necessary to perform sintering in a reducing atmosphere from the viewpoint of removal of the surface oxide film.

Therefore, a paste composition containing copper particles that can be sintered at low temperature even if it is not in a reducing atmosphere, has excellent thermal conductivity, good bonding characteristics, and has reflow resistance and is manufactured using the paste composition Of semiconductor devices and electrical and electronic components.

The paste composition of this embodiment contains (A) copper microparticles with a thickness or short diameter of 10 to 500 nm, and (B) a sintering aid containing an acid anhydride structure, and the above-mentioned (A) copper microparticles are blended with respect to 100 parts by mass (B) 0.01 to 1 part by mass of sintering aid.

As described above, the paste composition of the present embodiment includes (A) copper particles having a thickness or short diameter of 10 to 500 nm, and (B) a sintering aid including an acid anhydride structure.

Hereinafter, the present invention will be described in detail with reference to an embodiment.

<Paste composition> (Copper particles)

The (A) copper microparticles used in this embodiment are not particularly limited as long as the thickness or short diameter is 10 to 500 nm. For the shape of the (A) copper fine particles, for example, spherical, plate, flake, scaly, dendritic, rod, linear, etc. can be used. Here, in terms of plate shape, flake shape, and scale shape, as long as the thickness satisfies the above range, and in terms of dendritic shape, rod shape, linear shape, and spherical shape, as long as the shortest diameter of the diameter satisfies The above range is sufficient. The so-called "diameter" here, for example, in terms of dendritic, rod, and linear shapes, means the vertical section relative to the long axis of these Surface, in terms of spherical shape, means the length of the diameter in the section through the center. In addition, the method of calculating the diameter does not necessarily need to confirm the cross-section, and it can also be calculated by a method using electron micrographs as described below.

(A) The sintering temperature of the copper fine particles is reduced by the thickness or the short diameter satisfying the above range as described above, so the sintering operation can be easily performed. The (A) copper fine particles may be fine particles that are self-sintered at 100°C to 250°C. Furthermore, the so-called self-sintering here refers to the phenomenon that a metal bond is formed between the copper particles after the copper particles in a dispersed state under a specific temperature condition are aggregated.

In this embodiment, the (A) copper fine particles can be coated with a compound that inhibits oxidation on the surface thereof. Examples of such a compound include amine compounds and carboxylic acid compounds. Furthermore, in this specification, the term “coating” means that a compound that inhibits the above-mentioned oxidation is attached to all or part of the surface of the copper fine particles.

The surface of the copper microparticles may be coated with an amine compound, or may be coated with an amine alcohol represented by the following chemical formula (1).

In this way, the copper particles on the surface covered by the amine compound are coordinately bonded to the coating layer, so the coating layer can be easily and easily removed and sintered at a low temperature. Furthermore, by combining with (B) a sintering aid containing an acid anhydride structure described below, the copper particles are appropriately dispersed and sintered at a low temperature.

[化1]

(In the formula, R ¹ may be the same or different, and independently represent a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, a hydroxyl group or a methoxy group, n and m represent an integer from 0 to 10, and m+n is 10 or less )

Such copper particles coated with an amine compound can be obtained by mixing a copper-containing compound, an amine compound, and a reducing compound in an organic solvent to form a mixture, and heating the mixture until the copper-containing compound is thermally decomposed temperature.

The copper microparticles obtained in this way are coated with organic ions and amine compounds derived from the copper-containing compound generated by decomposing the copper-containing compound. The low-temperature sinterability of copper particles coated on the surface with these components is excellent.

The raw materials used in the manufacture of copper microparticles in this embodiment will be described below.

<Copper Compounds>

The copper-containing compound used here is a material used to precipitate metallic copper into copper particles. The copper-containing compound is decomposed by heating and releases copper ions. The copper ion is reduced to become metallic copper. The copper-containing compound may also be one that is decomposed by heating and releases copper ions and organic ions derived from the copper-containing compound.

Examples of such copper-containing compounds include copper carboxylate, cuprous oxide, copper nitrate, and copper sulfate formed by combining carboxylic acids such as formic acid, oxalic acid, malonic acid, benzoic acid, and phthalic acid with copper. Wait.

(Amine compound)

The amine compound used here has only to have an amine group and form a complex with a copper-containing compound (a copper-containing compound-amine complex). For example, amino alcohol, alkylamine, alkoxyamine, etc. can be mentioned. The amine compound can be appropriately selected and used depending on the thermal decomposition conditions of the copper-containing compound used, the expected characteristics of the produced copper particles, and the like.

These amine compounds adhere to the surface of the copper microparticles obtained by thermally decomposing the copper-containing compound, and have a function of inhibiting oxidation of the copper microparticles.

As the amine compound, it may also be an amine alcohol. The amino alcohol may also be an alcohol having an amino group represented by the above chemical formula (1).

Specific examples of this amino alcohol include aminoethanol, aminomethylheptanol, propanolamine, 1-amino-2-propanol, 2-aminodibutanol, 2-diethylaminoethanol , 3-Diethylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-amino-1,2-propanediol Wait. From the viewpoint of sinterability, the amine alcohol may have a boiling point of 70 to 300°C. From the viewpoint of workability, amino alcohol can be liquid at room temperature.

As long as the alkylamine is an amine compound in which an aliphatic hydrocarbon group such as an alkyl group is bonded to an amine group, its structure is not particularly limited. Examples of the amine compound include an alkyl monoamine having one amino group and an alkyl diamine having two amino groups. Furthermore, the above-mentioned alkyl group may further have a substituent.

Specifically, as the alkyl monoamine, dipropylamine, butylamine, dibutylamine, Hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, 3-aminopropyltriethoxysilane, dodecylamine, oleylamine, etc.

Examples of alkyldiamines include ethylenediamine, N,N-dimethylethylenediamine, N,N'-dimethylethylenediamine, N,N-diethylethylenediamine, N,N '-Diethylethylenediamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, N,N-dimethyl-1,3-diaminopropane, N,N'-dimethyl-1,3-diaminopropane, N,N-diethyl-1,3-diaminopropane, 1,4-diaminobutane, 1,5-di Amino-2-methylpentane, 1,6-diaminohexane, N,N'-dimethyl-1,6-diaminohexane, 1,7-diaminoheptane, 1 , 8-Diaminooctane and so on.

Furthermore, in order to react with the copper-containing compound to efficiently form the above-mentioned copper-containing compound-amine complex, the alkyl monoamine may also be a primary amine (R ² NH ₂ ) or a secondary amine (R ³ R ⁴ NH) And other alkyl monoamines.

In addition, the alkylamine does not include the alkoxyamine described below.

As the alkoxyamine, as long as it is an amine compound having an alkoxy group, its structure is not particularly limited. For example, an alkoxy monoamine having one amino group and an alkoxy diamine having two amino groups can be mentioned. amine. Specifically, as the alkoxy monoamine, methoxyethylamine, 2-ethoxyethylamine, 3-butoxypropylamine, etc. can be cited, and as the alkoxydiamine, N- Methoxy-1,3-propanediamine, N-methoxy-1,4-butanediamine, etc. Regarding alkoxy amines, considering the coordination ability of copper produced by reduction, it can also be alkoxy monoamines such as primary amine (R ² ONH ₂ ) or secondary amine (R ³ (R ⁴ O)NH) .

Here, the substituent R ² of the primary amine described in the above-mentioned alkylamine and alkoxyamine represents an alkyl group, and may be an alkyl group having 4 to 18 carbon atoms. In addition, the substituents R ³ and R ^{4 of the} secondary amine represent an alkyl group, and together they may be an alkyl group with 4 to 18 carbon atoms. The substituents R ³ and R ⁴ may be the same or different. Furthermore, these alkyl groups may have substituents, such as a silyl group and a glycidyl group.

The boiling point of the amine compound may be 70°C or higher and 200°C or lower, or 120°C or higher and 200°C or lower. If the boiling point of the amine compound is 70°C or higher, there is no concern that the amine will volatilize during the heating step. If it is 200°C or lower, it can be removed during the sintering of copper particles, making it easy to sinter at low temperatures. Furthermore, the boiling point of the amine compound may be higher than the heating temperature in the heating step, or lower than the sintering temperature during use.

In addition, as the amine compound, one type may be used alone or two or more types may be used in combination.

<Reducing compound>

The reducing compound used here is not particularly limited as long as it reduces copper ions generated by the decomposition of the copper-containing compound and has a reducing ability to free metallic copper. Furthermore, regarding the reducing compound, the boiling point may be 70° C. or higher, or may be higher than the heating temperature in the heating step. Furthermore, the reducing compound may be a compound dissolved in the organic solvent (C) described below containing carbon, hydrogen, and oxygen.

As such a reducing compound, typically, a hydrazine derivative is mentioned. Examples of the hydrazine derivatives include hydrazine monohydrate, methylhydrazine, ethylhydrazine, n-propylhydrazine, isopropylhydrazine, n-butylhydrazine, isobutylhydrazine, second butylhydrazine, tertiary butylhydrazine, and n-pentylhydrazine , Isopentylhydrazine, neopentylhydrazine, third pentylhydrazine, n-hexylhydrazine, isohexylhydrazine, n-heptylhydrazine, n-octylhydrazine, n-nonylhydrazine, n-decylhydrazine, n-undecylhydrazine, n-dodecylhydrazine, cyclohexane Hydrazine, phenylhydrazine, 4-methylphenylhydrazine, benzylhydrazine, 2-phenylethylhydrazine, 2-hydrazinoethanol, acetylhydrazine, etc.

<Organic solvent>

When manufacturing the copper microparticles used in this embodiment, the above-mentioned copper-containing compound, amine compound, and reducing compound can be mixed in an organic solvent.

The organic solvent used here can be used without particular limitation as long as it can be used as a reaction solvent that does not hinder the properties of complexes and the like generated from the mixture obtained by the above mixing. The organic solvent may be an alcohol exhibiting compatibility with the aforementioned reducing compound.

In addition, since the reduction reaction by the copper ion of the reducing compound is an exothermic reaction, it may also be an organic solvent that does not volatilize in the reduction reaction. Therefore, the organic solvent has a boiling point of 70°C or higher, and may contain carbon, hydrogen, and oxygen. If the boiling point of the organic solvent is 70°C or higher, the production of copper ions produced by the decomposition of the copper-containing compound-alkanolamine compound complex, and the control of the precipitation of copper ions caused by the reduction of the produced copper ions It becomes easy and the shape of copper particles is stable.

Examples of the above-mentioned alcohols used as organic solvents include: 1-propanol, 2-propanol, butanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, 1,3-propanediol, 1,2 -Propylene glycol, butyl carbitol, butyl carbitol acetate, ethyl carbitol, ethyl carbitol acetate, diethylene glycol diethyl ether, butyl cellosolve, etc.

In addition, the above-mentioned amine alcohol and reducing compound are not included in this organic solvent.

The copper-containing compound, the amine compound, the reducing compound, and the organic solvent added as necessary can be used to produce copper fine particles as follows.

<Formation of the mixture>

The mixture is formed by first containing an organic solvent in a reaction container, and then mixing a copper-containing compound, an amine compound, and a reducing compound. The order of the mixing may be any order of mixing the above-mentioned compounds.

When the copper-containing compound and the amine compound are formed efficiently, the copper-containing compound and the amine compound can be mixed first, and mixed at 0~50℃ for about 5~30 minutes, and then the reducing compound is added for mixing .

During the mixing, with respect to the usage amount of each compound, 0.5 to 10 mol of amine compound amine alcohol and 0.5 to 5 mol of reducing compound can be prepared with respect to 1 mol of copper-containing compound. At this time, the organic solvent should just be an amount which can fully react each component. For example, about 50~2000mL can be used.

<The heating of the mixture>

In the next step, the mixture obtained by mixing the above is sufficiently heated to carry out the thermal decomposition reaction of the copper-containing compound. By this heating, the copper-containing compound forming the complex is decomposed into organic ions derived from the copper-containing compound and copper ions. The copper ions are reduced by the reducing compound, and metallic copper is precipitated and grown into copper fine particles.

In addition, at this time, the organic ion derived from the copper-containing compound generated at the same time as the precipitation of metallic copper tends to be located on the specific crystal plane of the precipitated metallic copper. Therefore, the growth direction of the produced copper particles can be controlled, and plate-shaped copper particles can be obtained efficiently.

In addition, the amine compound has a function of preventing the coarsening of the particles by adhering to the surface of the copper fine particles to reduce growth.

The heating temperature in the heating step of the mixture is a temperature that can thermally decompose and reduce the copper-containing compound to generate plate-shaped copper particles. The heating temperature may be 70°C to 150°C, or 80 to 120°C, for example. Furthermore, at this time, the heating temperature may be lower than the boiling point of the raw material components and the organic solvent. If the heating temperature is 70° C. or higher, the thermal decomposition reaction of the copper-containing compound proceeds stably, so copper fine particles can be efficiently produced. In addition, if the heating temperature is 150°C or less, the volatilization of the amine compound will be reduced, so the uniformity in the system can be maintained, and the thermal decomposition of the copper-containing compound can proceed stably, so copper particles can be produced efficiently.

The solids precipitated here can be dried under reduced pressure after being separated from organic solvents by centrifugal separation or the like. By this operation, the copper fine particles of this embodiment can be obtained.

<Shape and size of copper particles>

The copper microparticles of this embodiment are in a state in which the amine compound forms a coordination bond on the copper atom generated by the thermal decomposition of the complex formed by the copper-containing compound and the reducing agent in the amine compound as described above.

It is speculated that by the aggregation of these copper atoms, copper fine particles coated with an amine compound can be formed. In the case of using copper carboxylate as the copper-containing compound, it is presumed that the obtained copper fine particles are coated with amine compounds and organic ions derived from copper carboxylate generated by thermal decomposition of copper carboxylate. Such copper particles have specific characteristics and shapes derived from molecules on the coated surface.

Therefore, by appropriately selecting the types of copper-containing compound, amine compound, and reducing agent used, and the reaction temperature, copper particles of any shape and size can be obtained.

Furthermore, by adding amine alcohol as an amine compound and other amine compounds to the mixture of the copper-containing compound and the reducing agent, the copper fine particles produced by the thermal decomposition are also covered by the other amine compound. Thereby, the oxidation of copper particles can be reduced, and the growth direction of copper particles can be controlled.

If the growth direction of metallic copper is controlled in this way, the obtained copper microparticles have a plate shape.

The copper microparticles obtained by the above-mentioned copper microparticle manufacturing method can be fired at a low temperature. The paste composition using the copper microparticles can be fired even if it is not in a reducing atmosphere. In addition, even if the copper fine particles are fired at a low temperature, the electrical resistance can be lowered, and the amount of outgassing that can cause the voids is reduced, so that a dense sintered film can be obtained.

According to the above-mentioned method for producing copper microparticles, it is possible to efficiently produce copper microparticles that can be fired at a low temperature in the atmosphere by simple operations.

Furthermore, the shape of the obtained copper microparticles can be confirmed by observation with a scanning electron microscope (manufactured by JEOL Ltd., trade name: JSM-7600F; SEM). In addition, the sizes (thickness, short diameter, and long diameter) of the copper particles in this specification are in the form of an average value of 10 copper particles (n=10) randomly selected based on the same SEM observation image. Figure out. In addition, the average value is an arithmetic average value, and when calculating the average value, it may be 10 or more copper particles.

The (B) sintering aid containing an acid anhydride structure used in this embodiment is not particularly limited as long as it promotes the sintering of the (A) copper fine particles or densifies the sintered body obtained by sintering. The (B) sintering aid has a structure formed by dehydration and condensation of two oxygen-containing acid molecules. The sintering aid may also have a structure formed by intramolecular dehydration and condensation of carboxylates of compounds having multiple carboxyl groups.

In particular, since carboxylic acid anhydride has a high coordination ability on the surface of copper particles, it will replace the protective group on the surface of copper particles and coordinate carboxylic acid anhydride on the surface of copper particles. The dispersibility of copper particles with carboxylic anhydride coordinated on the surface will be improved. In addition, since carboxylic anhydride is excellent in volatility, low-temperature sinterability is improved.

As the (B) sintering aid, specifically, acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, trimethylacetic anhydride, caproic anhydride, heptanoic anhydride, capric anhydride, lauric anhydride, Myristic anhydride, palmitic anhydride, stearic anhydride, behenic anhydride, crotonic anhydride, methacrylic anhydride, oleic anhydride, linoleic anhydride, chloroacetic anhydride, iodoacetic anhydride, dichloroacetic anhydride, trifluoroacetic anhydride , Chlorodifluoroacetic anhydride, trichloroacetic anhydride, pentafluoropropionic anhydride, heptafluorobutyric anhydride, succinic anhydride, methylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, itaconic anhydride, maleic anhydride, Glutaric anhydride, diglycolic anhydride, benzoic anhydride, phenyl succinic anhydride, phenyl maleic anhydride, high phthalic anhydride, isatin anhydride, phthalic anhydride, tetrafluorophthalic anhydride Acid anhydride, tetrabromophthalic anhydride, etc.

Among these, compounds that do not contain aromatics have no possibility of generating voids and are excellent in low-temperature sintering properties.

The melting point of the (B) sintering aid used in this embodiment can be in the range of 40 to 150°C. If the melting point of the sintering aid is in this range, the sintering acceleration of the paste composition is improved, and workability such as the stability of the life of the paste composition is improved.

The boiling point of the (B) sintering aid used in this embodiment can be 100~300°C, or 100~275°C. If the boiling point is in this range, there is no risk of void generation. By blending this acid anhydride as a sintering aid, a paste composition with improved adhesive properties, thermal conductivity, and reflow peel resistance can be obtained.

Regarding the blending amount of the (B) sintering aid, when the (A) copper fine particles are set to 100 parts by mass, it can be 0.01 to 1 part by mass. If the blending amount of the sintering aid is 0.01 part by mass or more, the adhesive properties are improved, and if it is 1 part by mass or less, there is no possibility of voids, so a paste composition with improved thermal conductivity and reflow peel resistance can be obtained.

Furthermore, (C) an organic solvent may also be used for the paste composition of this embodiment.

As long as the (C) organic solvent used here is a solvent that functions as a reducing agent, a known solvent can be used. The (C) organic solvent may be an alcohol, for example, an aliphatic polyol. Examples of the aliphatic polyol include glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, glycerin, and polyethylene glycol. These organic solvents can be used alone or in combination of two or more.

Regarding the paste composition of this embodiment, since a dense sintered structure can be obtained by using alcohol as the organic solvent (C), it has high conductivity and is dense with substrates such as lead frames. Higher accessibility.

The mechanism is presumed as follows.

Since the junction is sandwiched between the semiconductor element and the substrate, the alcohol is partially reflowed due to heating during sintering. Therefore, the alcohol does not volatilize immediately, but temporarily stays at the joining site. At this time, the copper oxide partially present in the copper particles of the paste composition and the oxide metal (for example, copper oxide) present on the surface of the substrate to be joined are reduced to a metal (for example, copper) by alcohol. Thereafter, the copper particles are sintered with the reduced metal (for example, copper).

As a result, the paste composition at the bonding site forms a metal bond with high conductivity and high adhesion to the substrate.

(C) The boiling point of the organic solvent can be specifically 100 to 300°C, or 150 to 290°C. If the boiling point is 100°C or higher, the volatility will not become too high even at room temperature, the reduction ability based on the volatilization of the dispersion medium can be maintained, and stable adhesive strength can be obtained. In addition, if the boiling point is 300°C or less, sintering of the cured film (conductive film) is likely to occur, and a film with excellent density can be formed. In addition, it is possible to reduce the situation that the organic solvent does not volatilize and the organic solvent remains in the film.

When the organic solvent is blended, the blending amount may be 7-20 parts by mass when the copper particles are set to 100 parts by mass. If it is 7 parts by mass or more, the viscosity will not become too high and workability can be improved. If it is 20 parts by mass or less, the viscosity will not become too low, and the copper sinking in the paste can be reduced, thereby improving reliability.

Furthermore, (D) thermosetting resin can also be used for the paste composition of this embodiment.

The (D) thermosetting resin used in this embodiment is generally used as an adhesive The thermosetting resin can be used without particular limitation. The thermosetting resin may be a liquid resin, or a liquid resin at room temperature (25°C). Examples of the (D) thermosetting resin include cyanate ester resins, epoxy resins, radically polymerizable acrylic resins, maleimide resins, and the like. These can be used alone or in combination of two or more kinds. By making the paste composition of this embodiment contain (D) thermosetting resin, it can be set as the adhesive material (paste) which has moderate viscosity. In addition, if the paste composition of the present embodiment contains a thermosetting resin, the temperature of the paste composition will rise due to the heat of reaction at the time of curing, and the sinterability of the copper particles will be promoted.

Here, when the (D) thermosetting resin is blended, when the (A) copper fine particles are set to 100 parts by mass, they are blended so as to be 1-20 parts by mass. If the thermosetting resin is 1 part by mass or more, the adhesiveness obtained by the thermosetting resin can be sufficiently obtained, and if the thermosetting resin is 20 parts by mass or less, high thermal conductivity can be sufficiently ensured, so that Improve heat dissipation. In addition, the organic component does not become excessive, and deterioration due to light and heat is suppressed. As a result, the life of the light-emitting device can be increased. By setting it in such a blending range, the adhesive properties of the thermosetting resin can be easily utilized to reduce the contact between copper particles and maintain the mechanical strength of the entire adhesive layer.

In the paste composition of the present embodiment, in addition to the above components, a hardening accelerator, a stress reducing agent such as rubber or silicone, a coupling agent, and a defoaming agent, which are generally formulated in this composition, can be formulated as needed. , Surfactants, colorants (pigments, dyes), various polymerization inhibitors, antioxidants, solvents, and other various additives. Each of these additives may be used alone or in combination of two or more kinds.

The paste composition of this embodiment can be prepared by the following method: each of the above-mentioned components (A) to (B), optional components of (C) and (D), and additives such as coupling agents. The solvent and the like are thoroughly mixed, and thereafter, kneading is performed by a disperser, a kneader, a three-roll mill, etc., and then defoaming is performed. Furthermore, in this specification, paste compositions also include pastes or inks with lower viscosity. The viscosity of the paste composition of this embodiment can be, for example, 20~300Pa‧s, or 30~200Pa‧s.

In addition, the adhesive strength of the paste composition of this embodiment may be 20 MPa or more, 25 MPa or more, or 30 MPa or more.

Furthermore, the above-mentioned viscosity and bonding strength can be measured by the methods described in the examples.

The paste composition of the present embodiment obtained in this way has high thermal conductivity and excellent heat dissipation. Therefore, if it is used as a bonding material in a substrate or the like of an element or a heat dissipation member, the heat dissipation from the inside of the device to the outside can be improved, and the product characteristics can be stabilized.

Next, the semiconductor device and electric/electronic equipment of this embodiment will be described.

The semiconductor device of this embodiment uses the above-mentioned paste composition to bond a semiconductor element to a substrate which becomes an element support member. That is, here, the paste composition is used as a die bonding paste, and the semiconductor element and the substrate are bonded and fixed via the paste composition.

Here, the semiconductor element should just be a well-known semiconductor element, for example, a transistor, a diode, etc. are mentioned. Furthermore, as this semiconductor element, a light-emitting element, such as an LED, is mentioned. In addition, the type of light-emitting element is not particularly limited. For example, it can be exemplified by MOCVD (Metal Organic Chemical Vapor Deposition, metal organic chemical vapor deposition) method to make InN, AlN, Nitride semiconductors such as GaN, InGaN, AlGaN, and InGaAlN are formed on a substrate as a light-emitting layer. In addition, the element supporting member may include a supporting member formed of materials such as copper, copper-plated copper, PPF (Pre-Plating Frame), glass epoxy, ceramics, and the like.

The paste composition of this embodiment can also be attached to a substrate that has not been metal-plated. The semiconductor device obtained in this way has a dramatic improvement in the connection reliability of the temperature cycle after mounting. In addition, since the resistance value is sufficiently small and the change over time is small, it has the advantage of less reduction in output over time and long life even if it is driven for a long time.

In addition, the electric and electronic equipment of this embodiment is formed by using the above-mentioned paste composition to bond the heat-dissipating member to the heat-generating member. That is, here, the paste composition is used as a material for adhering a heat dissipation member, and the heat dissipation member and the heat generating member are bonded and fixed via the paste composition.

Here, as the heating member, the above-mentioned semiconductor element or a member having the semiconductor element may be used, or other heating members may be used. Examples of heat generating components other than semiconductor elements include optical pickups, power transistors, and the like. Moreover, as a heat dissipation member, a heat sink, a heat sink, etc. are mentioned.

As described above, by adhering the heat-radiating member to the heat-generating member using the above-mentioned paste composition, the heat generated in the heat-generating member can be efficiently released to the outside by the heat-radiating member, and the temperature rise of the heat-generating member can be suppressed. Furthermore, the heat-generating component and the heat-dissipating component can be directly bonded via the paste composition, or indirectly bonded with other components with higher thermal conductivity between them.

[Example]

Next, the present embodiment will be described in further detail with examples, but the present embodiment is not limited by these embodiments at all.

[Synthesis Example 1]

Copper citrate (5mmol), citric acid (3.75mmol), and butyl cellosolve (3ml) were added to a 50ml sample bottle, and mixed in an aluminum block heating mixer at 90°C for 5 minutes. 1-amino-2-propanol (60 mmol) was added thereto, and the mixture was heated for 5 minutes to prepare a copper precursor solution. The solution was cooled to room temperature, and then, hydrazinoethanol (20 mmol) dissolved in 3 mL of 1-propanol was added to the copper precursor solution in the sample bottle and stirred for 5 minutes.

It was heated and stirred again with an aluminum block heating mixer at 90°C for 2 hours. After 5 minutes, 2 mL of ethanol (Kanto Chemical, special grade) was added, and centrifugal separation (4000 rpm (1 minute)) was performed to obtain polyhedral powder-like copper particles 1 with a particle size of 0.22 μm. The copper particles 1 are coated with 1-amino-2-propanol on their surface.

[Synthesis Example 2]

Except that the 1-amino-2-propanol of Example 1 was replaced with 60 mmol of octylamine, in the same manner as in Synthesis Example 1, a plate-shaped powdery copper microparticle 2 with a particle size of 0.10 μm was obtained. The surface of the copper particles 1 is coated with octylamine.

(Examples 1 to 4, Comparative Example 1)

Mix the ingredients according to the composition (parts by mass) in Table 1, and knead with a roller to obtain a tree Fat paste. In addition, the characteristics of the obtained paste composition and its cured product were studied, and the following methods were used for evaluation. The results are shown in Table 1 together. Furthermore, the materials used in Examples 1 to 4 and Comparative Example 1 are as follows. Except for the copper microparticles obtained in Synthesis Examples 1 and 2, commercially available products were used.

[(A) Copper particles]

(A1): Commercially available copper particles (manufactured by Mitsui Metals, trade name: CH-0200; particle size: 0.16 μm)

(A2): Copper particles 1 (polyhedral shape, particle size 0.22μm)

(A3): Copper particles 2 (plate shape, particle size 0.10μm)

[(B) Sintering aid]

(B1): Sintering aid 1 (glutaric anhydride, manufactured by Wako Pure Chemical Industries Co., Ltd., melting point 50°C, boiling point 150°C)

(B2): Sintering aid 2 (succinic anhydride, manufactured by Wako Pure Chemical Industries, Ltd., melting point 118°C, boiling point 261°C)

[Other sintering aids]

Malonic acid (manufactured by Wako Pure Chemical Industry Co., Ltd., melting point 135℃)

[(C) Organic solvent]

(C1): Organic solvent 1 (diethylene glycol, manufactured by Tokyo Chemical Industry Co., Ltd.)

[(D) Thermosetting resin]

烷溶劑，回流30分鐘) (D1): Thermosetting resin 1 (diallyl bisphenol A diglycidyl ether type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name: RD-810NM; epoxy equivalent 223, hydrolyzable chlorine 150ppm (1N KOH-ethanol, two

Alkane solvent, reflux for 30 minutes)

(other)

Polymerization initiator: Dicumyl peroxide (manufactured by Nippon Oil & Fat Co., Ltd., trade name: Percumyl C; decomposition temperature in rapid heating test: 126°C)

<Evaluation method> [Viscosity]

The viscosity of the paste composition was measured at 25°C and 5 rpm using a D-type viscometer (3° cone).

[Thermal conductivity]

The thermal conductivity of the paste composition after curing is measured by the laser flash method according to JIS R 1611-1997 after curing at 200°C for 60 minutes.

[resistance]

The sample for resistance measurement was applied to a glass substrate (thickness 1 mm) by a screen printing method so as to have a thickness of 200 μm, and cured at 175°C, 200°C, 300°C, and 60 minutes.

The electrical resistance was measured by the four-terminal method using the product name "MCP-T600" (manufactured by Mitsubishi Chemical Corporation) on the obtained wiring.

[Die shear strength]

The sample for thermal bonding strength measurement is to use the obtained paste composition to fix a gold wafer with a gold vapor deposition layer on the back surface of the 4mm×4mm bonding surface on a pure copper frame and PPF (plated with Ni-PC/Au Copper frame), cured at 200°C for 60 minutes.

Adhesive strength under heat is measured after hardening and moisture absorption treatment (85°C, relative humidity 85%, 72 hours) using a fixed strength measuring device to measure the wafer shear strength under heat at 260°C.

[Adhesion strength after high temperature heat treatment]

After the high temperature heat treatment, the sample for the measurement of the thermal adhesion strength is obtained by using the obtained paste composition. The back gold wafer with the gold vapor deposition layer on the bonding surface of 4mm×4mm is fixed on the surface and Ni-PC/Au plating The coated Mo substrate is cured at 200°C for 60 minutes.

After the high temperature heat treatment, the thermal bonding strength (heat treatment) is performed by high temperature heat treatment (heat treatment at 250°C for 100 hours and 1000 hours), and then a fixed strength measuring device is used to shear the wafer at 260°C. The shear strength is measured.

The heat bonding strength after high temperature heat treatment (cold-heat cycle treatment) is for the cold-heat cycle treatment (the operation of heating from -40°C to 250°C and then cooling to -40°C is one cycle, and 100 cycles and 1000 cycles are performed) Each of the latter uses a fixed strength measuring device to measure the wafer shear strength when heated at 260°C.

[Heat and cold shock resistance]

The sample for measuring thermal shock resistance is to use the obtained paste composition to fix the back gold silicon wafer with gold vapor deposition layer on the 6mm×6mm bonding surface on the copper frame and PPF, and use the oven to carry out 200℃, 60 After heating and curing (OV curing) in minutes, the epoxy sealing material (trade name: KD-G3000C) manufactured by KYOCERA (stock) was used for molding under the following conditions.

Thermal shock resistance is performed at 85°C, 85% relative humidity, and 168 hours for moisture absorption. After that, IR reflow treatment (260°C, 10 seconds) and thermal cycle treatment (heating from -55°C to 150°C) The operation of cooling to -55°C is 1 cycle, performing 1000 cycles), and the number of internal cracks in each package after each treatment is observed with an ultrasonic microscope.

The evaluation result is based on 5 samples, indicating the number of samples with cracks.

Package body: 80pQFP (14mm×20mm×2mm thickness)

Chip: Silicon chip and gold-plated chip on the back

Lead frame: PPF and copper

Forming of sealing material: 175℃, 2 minutes

Post-mold curing: 175℃, 8 hours

From the above results, it can be seen that the paste composition of the present embodiment contains specific copper particles and a sintering aid containing an acid anhydride structure, and therefore has excellent thermal conductivity, excellent low-stress properties, good adhesive properties, and excellent reflow peel resistance.

In addition, the paste composition of the present embodiment has good adhesive strength especially when heated after high temperature treatment. Therefore, the paste composition can be used as a die bonding paste for device bonding or as a material for bonding heat dissipation members to obtain semiconductor devices and electrical and electronic equipment with excellent reliability.

Claims (6)

A paste composition comprising: (A) copper particles with a thickness or short diameter of 10 to 500 nm, and (B) a sintering aid containing acid anhydride with a melting point of 40 to 150°C and a boiling point of 100 to 300°C, the above (A) ) The copper microparticles are coated with an amine alcohol represented by the following chemical formula (1), and the (B) sintering aid is adjusted to 0.01 to 1 part by mass relative to 100 parts by mass of the (A) copper microparticles;

(In the formula, R ¹ may be the same or different, and independently represent a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, a hydroxyl group or a methoxy group, n and m represent an integer from 0 to 10, and m+n is 10 or less ). Such as the paste composition of claim 1, which further includes (C) an organic solvent, and the (C) organic solvent is an alcohol that functions as a reducing agent. The paste composition of claim 1 or 2, which further contains (D) a thermosetting resin. A semiconductor device comprising: a substrate, and a semiconductor element attached to the substrate via a hardened product of a die bonding material including the paste composition of any one of claims 1 to 3. The semiconductor device of claim 4, wherein the semiconductor element is a light-emitting element. An electric and electronic equipment comprising: a heat-generating component, and a heat-dissipating component adhered to the heat-generating component via a hardened product of the heat-dissipating component bonding material including the paste composition of any one of claims 1 to 3.