Low-sheet-resistance tungsten-copper electronic paste for high-temperature co-fired multilayer ceramic substrate and preparation method of low-sheet-resistance tungsten-copper electronic paste

Abstract

The invention discloses low-sheet-resistance tungsten-copper electronic paste for a high-temperature co-fired multilayer ceramic substrate and a preparation method of the low-sheet-resistance tungsten-copper electronic paste, and relates to the technical field of high-temperature co-fired multilayer ceramic substrate processing. The tungsten-copper electronic paste is composed of 72-85 wt% of tungsten-copper powder, 10-23 wt% of an organic carrier and 5-8 wt% of a binding phase. The tungsten copper powder with the tungsten-coated copper structure is adopted, and the phenomenon that copper is burnt out in the high-temperature sintering process is avoided. And the adopted organic carrier can maintain the morphology characteristics of the printed slurry, and the resolution ratio reaches 100 microns, so that the slurry is not easy to agglomerate and precipitate. And the adopted bonding phase can be tightly combined on the aluminum oxide ceramic substrate, and the adhesive force reaches 5 (0) level. Compared with other tungsten-copper paste on the market, the tungsten-copper paste has the advantages of low sheet resistance value, good printing performance, stable performance, storage resistance and the like, and can achieve the results of low sheet resistance value, clear printed circuit, smooth surface and good film adhesion effect after being sintered at the high temperature of 1350 DEG C.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature co-fired multilayer ceramic substrate processing, and in particular to a low-square-resistance tungsten-copper electronic slurry for high-temperature co-fired multilayer ceramic substrate and a preparation method thereof. Background Art

[0002] High temperature co-fired multilayer ceramic substrate (HTCC) is often used in the packaging field of electronic devices with high thermal stability and mechanical strength requirements due to its good thermal stability and mechanical strength. However, due to its high co-firing temperature, the choice of conductive paste is limited. The use of low melting point metal materials such as Au, Ag, Cu, etc. will cause burnout during the sintering process. Therefore, materials with higher melting points such as W / Mo / W-Cu / Mo-Mn are generally used, but they will have poor conductivity and high square resistance, resulting in signal transmission loss.

[0003] To solve this problem, the present invention provides a tungsten-copper electronic paste for high-temperature co-fired multilayer ceramic substrates, which reduces power loss by reducing square resistance without causing the paste to burn out. Summary of the invention

[0004] The purpose of the present invention is to provide a low square resistance tungsten-copper electronic paste for high-temperature co-fired multilayer ceramic substrates and a preparation method thereof. A tungsten-copper powder with a tungsten-coated copper structure is used to avoid copper burnout during high-temperature sintering. The obtained tungsten-copper electronic paste has the advantages of low square resistance, not easy to oxidize, and a smooth surface without warping.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0006] A low square resistance tungsten copper electronic paste for high temperature co-fired multilayer ceramic substrate consists of 72-85wt% tungsten copper powder, 10-23wt% organic carrier and 5-8wt% bonding phase.

[0007] As the preferred technical solution of the present invention, the tungsten copper powder used in the low square resistance tungsten copper electronic paste is a tungsten-coated copper structure, with a copper content of 5-40%, a particle size of 0.2-27 μm, and a loose density of 0.87-4.62 g / cm 3 , tap density 1.21~9.26g / cm 3 .

[0008] The organic carrier used is composed of an organic solvent, a resin, a thickener and an auxiliary agent, wherein the proportions of the organic solvent, the resin, the thickener and the auxiliary agent in the organic carrier are 80-98wt%, 0.1-6.9wt%, 0.2-9.47wt% and 0.2-8.7wt% respectively.

[0009] Further preferably, the organic solvent in the organic carrier is selected from one or more of terpineol, alcohol ester dodecanol, propylene glycol, phthalic acid, diethylene glycol butyl ether, and tributyl citrate, the resin is selected from polyvinyl butyral, the thickener is selected from ethyl cellulose, and the auxiliary agent is selected from one or more of triethanolamine, N-methylacrylic acid, Span 85, hydrogenated castor oil, and lecithin.

[0010] The bonding phase used is composed of silicon dioxide, barium oxide, copper oxide, titanium dioxide, aluminum oxide, magnesium oxide and manganese dioxide, and the proportions of silicon dioxide, barium oxide, copper oxide, titanium dioxide, aluminum oxide, magnesium oxide and manganese dioxide in the bonding phase are 45-65wt%, 12-24wt%, 9-27wt%, 9-27wt%, 1-6wt%, 1-6wt% and 3-13wt%, respectively.

[0011] The present invention also proposes a method for preparing the low square resistance tungsten copper electronic paste, the steps of which are as follows:

[0012] Step 1: Preparation of organic carrier:

[0013] Prepare an organic carrier according to a preset ratio, place it in a water bath and heat it to 40-90°C, add a stirring rotor and stir for 4-8 hours, keep warm for 1-2 hours, and finally obtain an organic carrier;

[0014] Step 2: Mixing the conductive phase with the adhesive phase:

[0015] According to the preset ratio, mix the tungsten copper powder with the binder phase, and use a three-dimensional powder mixer to mix the powder at a uniform speed for 10 to 15 hours;

[0016] Step 3: Slurry grinding:

[0017] An organic carrier is added to the mixed conductive phase and the adhesive phase, and a mortar is used for preliminary grinding and dispersion. The ground slurry is secondarily ground with a three-roll grinder to obtain a low square resistance tungsten copper electronic slurry for high temperature co-fired multilayer ceramic substrates.

[0018] Compared with the prior art, the beneficial effects of the present invention are mainly manifested in:

[0019] 1. In view of the copper burning-out phenomenon of tungsten-copper slurry during high-temperature sintering, the present invention adopts tungsten-copper powder with a tungsten-coated copper structure to avoid the copper burning-out phenomenon during high-temperature sintering.

[0020] 2. The organic carrier used in the present invention can maintain the morphological characteristics of the slurry after printing, with a resolution of 100 μm, making it difficult for the slurry to agglomerate and precipitate.

[0021] 3. The bonding phase used in the present invention can achieve tight bonding on the alumina ceramic substrate, and the adhesion reaches level 5(0).

[0022] 4. Compared with other tungsten-copper pastes on the market, the tungsten-copper paste prepared by the present invention has low square resistance, good printing performance, stable performance, and storage resistance. After high-temperature sintering at 1350°C, it can achieve low square resistance, clear printed circuits, smooth surface, and good film adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The circuit printed on the alumina ceramic substrate by the tungsten-copper electronic paste prepared in Example 2 of the present invention is shown.

[0024] Figure 2 The figure shows the surface morphology of the tungsten-copper electronic paste prepared in Example 2 of the present invention after sintering on an alumina ceramic substrate. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0026] Example 1

[0027] This embodiment prepares a low square resistance tungsten copper electronic paste for high temperature co-fired multi-layer ceramic substrate, and its components and proportions are as follows:

[0028] 1. Tungsten copper powder 82wt%, which is a tungsten-coated copper structure, with a copper content of 25%, a particle size of 6.87μm, and a bulk density of 3.31g / cm 3 , tap density 7.85g / cm 3 .

[0029] 2. Organic carrier 12wt%, composed of:

[0030] 2.1. Organic solvent 87wt%: 15wt% pineol, 30wt% terpineol, 5wt% propylene glycol, 10wt% phthalic acid, 25wt% diethylene glycol butyl ether, and 2wt% tributyl citrate.

[0031] 2.2. Resin 5wt%: 5wt% polyvinyl butyral.

[0032] 2.3. Thickener 3wt%: 3wt% ethyl cellulose.

[0033] 2.4. Auxiliary agents 5wt%: 0.2wt% triethanolamine, 0.8wt% N-methylacrylic acid, 3wt% hydrogenated castor oil, 1wt% lecithin.

[0034] 3. The binder phase is 6wt%, and the composition is:

[0035] Silicon dioxide 48wt%, barium oxide 16wt%, copper oxide 12wt%, titanium dioxide 12wt%, aluminum oxide 4wt%, magnesium oxide 4wt%, and manganese dioxide 4wt%.

[0036] The preparation steps are as follows:

[0037] Step 1: Preparation of organic carrier:

[0038] The organic carrier was prepared according to a preset ratio, placed in a water bath and heated to 90° C., a stirring rotor was added and stirred for 8 h, and the mixture was kept warm for 1 h to finally obtain the organic carrier.

[0039] Step 2: Mixing the conductive phase with the adhesive phase:

[0040] According to the preset ratio, the tungsten copper powder is mixed with the binder phase, and the powder is mixed at a constant speed for 15 hours using a three-dimensional powder mixer.

[0041] Step 3: Slurry grinding:

[0042] An organic carrier is added to the mixed conductive phase and the adhesive phase, and a mortar is used for preliminary grinding and dispersion. The ground slurry is secondarily ground with a three-roll grinder to obtain a low square resistance tungsten copper electronic slurry for high temperature co-fired multilayer ceramic substrates.

[0043] Example 2

[0044] Tungsten copper powder with a copper content of 28% was selected for preparation, and the process was the same as that in Example 1.

[0045] Example 3

[0046] Tungsten copper powder with a copper content of 30% was selected for preparation, and the process was the same as that in Example 1.

[0047] The tungsten copper electronic paste of Example 1-3 was printed on an alumina green ceramic tape by screen printing, the screen mesh number was 325 mesh, and the square resistance and resistivity were tested after sintering at 1350° C. The results are shown in Table 1:

[0048] Table 1

[0049] Example 1 2 3 Square resistance / (mΩ / sq) 4.73 4.43 4.33 Resistivity / (Ω·m) <![CDATA[4.96×10 -8 ]]> <![CDATA[4.57×10 -8 ]]> <![CDATA[4.42×10 -8 ]]>

[0050] Combination Figure 1 , 2 It can be seen from Table 1 that the organic carrier used in the present invention can maintain the morphological characteristics of the slurry after printing, the resolution reaches 100μm, and the slurry is not easy to agglomerate and precipitate. Compared with other tungsten copper slurries on the market, it has low square resistance, good printing performance, stable performance, and storage resistance. After high-temperature sintering at 1350℃, it can achieve low square resistance, clear printed circuits, smooth surface, and good film adhesion.

[0051] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A low square resistance tungsten copper electronic paste for high temperature co-fired multilayer ceramic substrate, characterized in that: The invention is composed of 72-85wt% tungsten copper powder, 10-23wt% organic carrier and 5-8wt% bonding phase.

2. The low square resistance tungsten copper electronic paste according to claim 1, characterized in that: The tungsten copper powder used is a tungsten-coated copper structure with a copper content of 5-40%, a particle size of 0.2-27 μm, and a bulk density of 0.87-4.62 g / cm 3 , tap density 1.21~9.26g / cm 3 .

3. The low square resistance tungsten copper electronic paste according to claim 1, characterized in that: The organic carrier used is composed of an organic solvent, a resin, a thickener and an auxiliary agent, wherein the proportions of the organic solvent, the resin, the thickener and the auxiliary agent in the organic carrier are 80-98wt%, 0.1-6.9wt%, 0.2-9.47wt% and 0.2-8.7wt% respectively.

4. The low square resistance tungsten copper electronic paste according to claim 3, characterized in that: The organic solvent is selected from one or more of terpineol, alcohol ester dodecanol, propylene glycol, phthalic acid, diethylene glycol butyl ether, and tributyl citrate; the resin is selected from polyvinyl butyral; the thickener is selected from ethyl cellulose; and the auxiliary agent is selected from one or more of triethanolamine, N-methylacrylic acid, Span 85, hydrogenated castor oil, and lecithin.

5. The low square resistance tungsten copper electronic paste according to claim 1, characterized in that: The bonding phase used is composed of silicon dioxide, barium oxide, copper oxide, titanium dioxide, aluminum oxide, magnesium oxide and manganese dioxide, and the proportions of silicon dioxide, barium oxide, copper oxide, titanium dioxide, aluminum oxide, magnesium oxide and manganese dioxide in the bonding phase are 45-65wt%, 12-24wt%, 9-27wt%, 9-27wt%, 1-6wt%, 1-6wt% and 3-13wt%, respectively.

6. The method for preparing the low square resistance tungsten copper electronic paste according to any one of claims 1 to 5, characterized in that: Here are the steps: Step 1: Preparation of organic carrier: Prepare an organic carrier according to a preset ratio, place it in a water bath and heat it to 40-90°C, add a stirring rotor and stir for 4-8 hours, keep warm for 1-2 hours, and finally obtain an organic carrier; Step 2: Mixing the conductive phase with the adhesive phase: According to the preset ratio, mix the tungsten copper powder with the binder phase, and use a three-dimensional powder mixer to mix the powder at a uniform speed for 10 to 15 hours; Step 3: Slurry grinding: An organic carrier is added to the mixed conductive phase and the adhesive phase, and a mortar is used for preliminary grinding and dispersion. The ground slurry is secondarily ground with a three-roll grinder to obtain a low square resistance tungsten copper electronic slurry for high temperature co-fired multilayer ceramic substrates.

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