CN1590571A - Tungsten copper functional composite material and its preparation technology - Google Patents

Abstract

The invention relates to a tungsten-copper functional composite material and a preparation process thereof. The composite material comprises the following components and contents (weight): 70% to 95% of tungsten and 5% to 30% of copper; the preparation process includes powder treatment and adding an inducer And mixing, compression molding, pre-sintering, infiltration and other steps. The alloy prepared by this process has the combination of low thermal expansion coefficient of tungsten and high thermal conductivity of copper, which can achieve good matching and sealing with semiconductor silicon, arsenic, gallium arsenide, aluminum oxide and beryllium oxide, and can be used as Heat sink substrates for CPU, IC, solid-state microwave tubes and other highly airtight packages.

Description

A kind of tungsten-copper functional composite material and its preparation process

technical field

The invention relates to an alloy and a preparation process thereof, in particular to a tungsten-copper two-phase metal composite material and a preparation process thereof.

Background technique

In recent years, the demand for substrates, inlays, connectors and heat dissipation components in large-scale integrated circuits and high-power microwave devices has expanded rapidly. The tungsten-copper composite material is composed of two materials with different properties, tungsten and copper. It inherits the respective advantages of the two materials and achieves properties that cannot be possessed by a single material. It can achieve the above-mentioned by changing the relative content of the constituent phases Requirements. The high thermal conductivity and heat resistance of tungsten-copper composite materials can increase the power of microelectronic devices, and the thermal expansion coefficient of tungsten-copper composite materials can match many semiconductor materials in microelectronic devices. However, because the current preparation process of tungsten-copper alloy has not passed the standard, the alloy material cannot meet the requirements for use.

Contents of the invention

The purpose of the present invention is to provide a tungsten-copper functional composite material with excellent material performance and reasonable manufacturing process and its preparation process in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A tungsten-copper functional composite material is characterized in that the composite material comprises the following components and contents (weight): 70-95% of tungsten and 5-30% of copper.

The components and content (weight) are: 80-90% of tungsten and 10-20% of copper.

The physical parameters of the composite material are: density 15.4-17.3 g/cm ³ , thermal conductivity 150-210 W/m·Kelvin (w/m·K), thermal expansion coefficient 6.5-8.3 ppm/°C.

A preparation process of tungsten-copper functional composite material is characterized in that the process comprises the following steps:

(1) Powder processing

Take tungsten powder with a Fibonacci average particle size of 5-15 microns, pass through 850-1050°C dry ammonia decomposition gas protection, keep warm for ≤60 minutes, and take -200 mesh electrolytic copper powder, pass through 300-450°C dry ammonia decomposition gas protection, heat preservation ≤60 minutes, standby;

(2) Add inducer and mixture

Use fine copper powder with a particle size of -500 mesh as an inducer and mix the above-mentioned tungsten powder evenly on a powder mixer;

(3) Compression molding

Put the above-mentioned mixture in the mold, and press it on a press, the pressure of the press is 6-8 tons/cm2;

(4) Pre-sintering

Pre-sintering the above-mentioned compacted green body at 1000-1200°C and keeping it warm for 30-120 minutes;

(5) Infiltration

The electrolytic copper powder prepared in step (1) is placed on the surface of the pre-sintered compact, and kept at a temperature of 1250-1400°C for 60-180 minutes to carry out infiltration treatment. Under protection, the tungsten-copper functional composite material is obtained;

The sum of the amount of fine copper powder added in the step (2) and the infiltration amount of the electrolytic copper powder in the step (5) is controlled at 5 to 30% (weight) of the composite material, and the step (2) The added amount of the tungsten powder is controlled to account for 70-95% (weight) of the composite material.

The added amount of the fine copper powder in the step (2) accounts for ≤5% (weight) of the composite material.

式中D为粉末混料机混料筒的直径，米。The speed of the powder mixer is within the critical speed range of 0.6 to 0.75 rpm, and the mixing time is 8 to 12 hours; the critical speed:

In the formula, D is the diameter of the mixing cylinder of the powder mixer, in meters.

The density of the green compact formed by pressing in the step (3) reaches 70-75% of the density of the composite material product.

The tungsten-copper composite material of the present invention is a two-phase pseudo-alloy composed of two metals, tungsten and copper. Tungsten and copper are immiscible in both liquid and solid states, and each maintains its original physical and mechanical properties after being evenly mixed. The addition of the inducer improves the compactness of the tungsten powder green body; improves the infiltration efficiency of copper and promotes the densification of the tungsten-copper material; ensures that the copper phase is fine and uniform. In order to avoid the mixing of impurities in the mixture, the present invention adopts dry mixing. In the mixing process, there are only two kinds of powders, tungsten powder and copper powder, and no other balls and solvents are added. The addition of the inducer copper powder increases the forming pressure of the tungsten copper powder, increases the density of the green body, and reduces the capillary pore size, which is beneficial to the formation of the tungsten copper skeleton and the infiltration of liquid phase copper. Because in the present invention, the tungsten-copper blank can obtain stable size control after being infiltrated with copper, so the density of the final product can be controlled by effectively controlling the size and weight of the pressed blank, and the densification of the product can be guaranteed. Using the infiltration method, the purpose of freely controlling the composition and properties of the composite material in a wide range can be achieved by changing the initial density and particle size of the low melting point skeleton metal. This alloy not only has the low thermal expansion coefficient of tungsten, but also has the high thermal conductivity of copper. It can achieve good matching and sealing with semiconductor silicon, arsenic, gallium arsenide, aluminum oxide, and beryllium oxide. It can be used as CPU, IC , solid-state microwave tubes and other highly airtight packaged heat sink substrates. As a tungsten-copper composite material used in microelectronic technology, the product of the invention has high density, high thermal conductivity and low expansion coefficient, and meets the requirements for use.

Detailed ways

Example 1

A tungsten-copper functional composite material comprises the following components and contents (weight): 85% tungsten and 15% copper.

The preparation process of the above-mentioned tungsten-copper functional composite material comprises the following steps:

(1) Powder processing

The tungsten powder is in accordance with the technical conditions of GB3458-1982 tungsten powder, the grade GW-1, and the Fischer average particle size is 5-15 microns; the electrolytic copper powder is in accordance with the GB5246-1985 electrolytic copper powder, the grade FTD1, -200 mesh 200 mesh sieve) powder.

The powder used in the present invention needs to undergo the following activation pretreatment, which is one of the characteristics of the present invention.

The tungsten powder is protected by 1000°C dry ammonia decomposition gas and kept warm for 30 minutes; the electrolytic copper powder is protected by 400°C dry ammonia decomposition gas and kept warm for 30 minutes.

(2) Add inducer and mixture

Adopt particle size to be the fine copper powder of -500 mesh as inducer and above-mentioned tungsten powder and mix evenly on powder mixer, wherein, tungsten powder consumption accounts for 85% (weight) of product total amount, and the add-on of fine copper powder is product total amount 4% (weight), the rotating speed of the powder mixer is within the critical speed range of 0.70 rpm, and the mixing time is 10 hours.

(3) Compression molding

The above-mentioned mixture is placed in a mold, and pressed on a press, the pressure of the press is 7.5 tons/cm 2 , and the density of the press-formed green body reaches about 73% of the density of the composite material product.

(4) Pre-sintering

The above-mentioned pressed green body was pre-sintered at 1100° C. and kept warm for 60 minutes.

(5) Infiltration

Place the electrolytic copper powder prepared in step (1) on the surface of the pre-sintered compact, the amount of the electrolytic copper powder accounts for 11% (weight) of the total product, and infiltrate at a temperature of 1350 ° C for 120 minutes treatment, the infiltration treatment process is carried out under the protection of dry ammonia decomposition gas, and the tungsten-copper functional composite material is obtained.

The physical parameters of the composite material prepared in this example are: density 16.25 g/cm 3 , thermal conductivity 176 w/m·K, thermal expansion coefficient 7.2 ppm/°C.

Example 2

A tungsten-copper functional composite material comprises the following components and contents (weight): 80% tungsten and 20% copper.

The preparation process of the above-mentioned tungsten-copper functional composite material comprises the following steps:

(1) Powder processing

The tungsten powder is in accordance with the technical conditions of GB3458-1982 tungsten powder, the grade GW-1, and the Fischer average particle size is 5-15 microns; the electrolytic copper powder is in accordance with the GB5246-1985 electrolytic copper powder, the grade FTD1, -200 mesh 200 mesh sieve) powder.

The powder used in the present invention needs to undergo the following activation pretreatment, which is one of the characteristics of the present invention.

The tungsten powder is protected by 1050°C dry ammonia decomposition gas and kept warm for 15 minutes; the electrolytic copper powder is protected by 450°C dry ammonia decomposition gas and kept warm for 10 minutes.

(2) Add inducer and mixture

Adopt granularity to be -500 purpose fine copper powder as inducer and above-mentioned tungsten powder and mix on powder mixer, wherein, tungsten powder consumption accounts for 80% (weight) of product total amount, and the add-on of fine copper powder is product total amount 2.5% (weight), the rotating speed of the powder mixer is within the critical speed range of 0.75 rev/min, and the mixing time is 12 hours.

(3) Compression molding

The above-mentioned mixture is placed in a mold and pressed into a press with a pressure of 7.0 tons/cm 2 , and the density of the pressed form reaches about 75% of the density of the composite product.

(4) Pre-sintering

The above-mentioned pressed green body was pre-sintered at 1200° C. and kept warm for 120 minutes.

(5) Infiltration

Place the electrolytic copper powder prepared in step (1) on the surface of the pre-sintered compact, the amount of the electrolytic copper powder accounts for 25% (weight) of the total product, and infiltrate at a temperature of 1400 ° C for 180 minutes treatment, the infiltration treatment process is carried out under the protection of dry ammonia decomposition gas, and the tungsten-copper functional composite material is obtained.

The physical parameters of the composite material prepared in this example are: density 15.52 g/cm ³ , thermal conductivity 200 w/m·K, thermal expansion coefficient 8.02 ppm/°C.

Example 3

A tungsten-copper functional composite material comprises the following components and contents (weight): 90% tungsten and 10% copper.

The preparation process of the above-mentioned tungsten-copper functional composite material comprises the following steps:

(1) Powder processing

The tungsten powder is in accordance with the technical conditions of GB3458-1982 tungsten powder, the grade GW-1, and the Fischer average particle size is 5-15 microns; the electrolytic copper powder is in accordance with the GB5246-1985 electrolytic copper powder, the grade FTD1, -200 mesh 200 mesh sieve) powder.

The powder used in the present invention needs to undergo the following activation pretreatment, which is one of the characteristics of the present invention.

The tungsten powder is protected by 950°C dry ammonia decomposition gas and kept warm for 60 minutes; the electrolytic copper powder is protected by 350°C dry ammonia decomposition gas and kept warm for 60 minutes.

(2) Add inducer and mixture

Adopt particle size to be the fine copper powder of -500 mesh as inducer and above-mentioned tungsten powder and mix on powder mixer, wherein, the consumption of tungsten powder accounts for 95% (weight) of product total amount, and the add-on of fine copper powder is product total amount 1% (weight), the rotating speed of the powder mixer is within the range of 0.60 critical speed, and the mixing time is 8 hours.

(3) Compression molding

The above mixture is placed in a mold, and pressed on a press with a pressure of 8 tons/cm ² , and the density of the press-formed green body reaches about 70% of the density of the composite material product.

(4) Pre-sintering

Pre-sinter the pressed green compact at 1000° C. and keep it warm for 30 minutes.

(5) Infiltration

Place the electrolytic copper powder prepared in step (1) on the surface of the pre-sintered compact, the amount of the electrolytic copper powder accounts for 4% (weight) of the total product, and infiltrate at a temperature of 1250 ° C for 60 minutes treatment, the infiltration treatment process is carried out under the protection of dry ammonia decomposition gas, and the tungsten-copper functional composite material is obtained.

The physical parameters of the composite material prepared in this example are: density 16.9 g/cm ³ , thermal conductivity 152.3 w/m·K, thermal expansion coefficient 6.35 ppm/°C.

Claims (7)

1. a tungsten copper functional composite material is characterized in that, this matrix material comprises following component and content (weight): tungsten 70～95%, copper 5～30%.

2. a kind of tungsten copper functional composite material according to claim 1 is characterized in that, described component and content (weight) are: tungsten 80～90%, copper 10～20%.

3. a kind of tungsten copper functional composite material according to claim 1 is characterized in that the physical parameter of described matrix material is: density 15.4～17.3 gram per centimeters ³, 150～210 watts of/meter Kelvins of thermal conductivity, thermal expansivity is 6.5～8.3ppm/ ℃.

4. the preparation technology of a tungsten copper functional composite material is characterized in that, this technology may further comprise the steps:

(1) powder treatment

Get the tungsten powder of 5～15 microns of Fei Shi mean particle sizes, through 850～1050 ℃ of dry decomposed ammonia body protections, be incubated≤60 minutes, other gets-200 purpose electrolytic copper powders, through 300～450 ℃ of dry decomposed ammonia body protections, is incubated≤60 minutes, and is stand-by;

(2) add inductor and batch mixing

Adopt granularity to mix on the powder mixer as inductor and above-mentioned tungsten powder for the thin copper powder of-500 purposes;

(3) compression moulding

Above-mentioned batch mixing is placed in the mould, and compression moulding on press, the pressure of press is 6～8 tons/centimetre ²

(4) presintering

The green compact of above-mentioned compression moulding through 1000～1200 ℃ of presintering, and are incubated 30～120 minutes;

(5) infiltration

The electrolytic copper powder of getting ready in the step (1) is placed one-tenth parison surface through presintering, be incubated 60～180 minutes down for 1250～1400 ℃ in temperature and carry out the infiltration processing, this infiltration treating processes is carried out under the protection of exsiccant decomposed ammonia body, obtains the tungsten copper functional composite material;

The molten milliosmolarity sum of the middle electrolytic copper powder of the add-on of thin copper powder and step (5) is controlled at 5～30% (weight) that account for matrix material in the described step (2), and the add-on of tungsten powder is controlled at 70～95% (weight) that account for matrix material in the described step (2).

5. the preparation technology of a kind of tungsten copper functional composite material according to claim 4 is characterized in that, the add-on of thin copper powder accounts for matrix material≤5% (weight) in the described step (2).

6. the preparation technology of a kind of tungsten copper functional composite material according to claim 4 is characterized in that, the rotating speed of described powder mixer is in 0.6～0.75 rev/min of critical speed range, and mixing time is 8～12 hours.

7. the preparation technology of a kind of tungsten copper functional composite material according to claim 4 is characterized in that, the green density of compression moulding reaches 70～75% of composite products density in the described step (3).