CN104952514A - Easily printed PCB (printed circuit board) silver paste and preparation method thereof - Google Patents

Abstract

The invention relates to an easily printed PCB (printed circuit board) silver paste, made with, by weight, 12 to 16 parts of glass frit, 7 to 9 parts of thermosetting acrylic resin, 2 to 4 parts of hydroxymethyl cellulose, 3 to 5 parts of butyl acetate, 6 to 8 parts of tributyl citrate, 0.4 to 0.7 part of oxidized castor oil, 1 to 2 parts of N-phenyl-2-naphthylamine, 0.2 to 0.5 part of cobalt acetate, 1 to 2 parts of anhydrous lanolin, 5 to 7 parts of ethylene glycol monobutyl ether, 5 to 7 parts of xylene, 7 to 10 parts of 1 to 5 nm copper powder, 55 to 60 parts of 1 to 5 micrometers silver powder, 2 to 4 parts of silver-coated TiO2 microspheres, and 4 to 7 parts of silver-coated SiO2 microspheres. The silver paste has good dispersity and levelling property and ease of printing, the printed circuit is continuous and clear, and no pores and cracks occur after drying; with the use of the low-melting glass frit, the adhesion to PCB is good, and shedding rarely occurs; with the use of the conductive micro-powder such as copper powder, consumption of the silver powder is reduced without affecting the conductivity.

Description

A kind of easily printing PCB silver slurry and preparation method thereof

Technical field

The invention belongs to electric slurry technical field, particularly relate to a kind of easily printing PCB silver slurry and preparation method thereof.

Background technology

In modern microelectronic industry, people require more and more higher to electronic devices and components, production adopts procedure more, standardization is carried out reducing costs, printed circuit board (PCB) (PCB) is exactly that this demand being applicable to microelectronics industry is born, match with the electric slurry such as resistance slurry, grout slurry and printed circuit board (PCB) (PCB) with regard to the conductor paste of the new requirement of demand, electrode slurry, dielectric paste accordingly, the research carrying out new conductor paste is also just imperative.

In general, the main component of electric slurry includes function mutually as metal, noble metal powder etc., inorganic binder as glass powder, oxide powder etc., organic binder bond, other solvent and additive.Usually, function in electric slurry plays electric action mutually, have good electric conductivity, is generally served as by metal dust or noble metal powder, conventional metal dust has copper powder, aluminium powder, zinc powder, nickel powder etc., and conventional precious metal powder has bronze, silver powder, platinum powder, palladium powder etc.Inorganic binder plays fixing electric slurry to base material, and generally served as by oxide powder and glass powder, but this composition is lower at the proportion of electric slurry, what have does not even have; Organic binder bond mainly works to make slurry have certain shape, is easy to printing or coating, mainly contain macromolecule resin, Small molecular resin etc. to serve as, along with this part effect in electric slurry of progress of chemical industry technology is more and more outstanding, especially, when being applied to silk screen printing, the composition changing organic binder bond just can change the printing of electric slurry, drying, sintering character.

In existing electric slurry field, it is high that silver system slurry has conductance, stable performance, with the feature such as substrate bond strength is large, is widely used in the production of the electronic devices and components such as integrated circuit, multi-chip module, thin film switch.But silver is precious metal, and cost is higher, and the silver powder major part in existing silver paste is micron-sized powder, and the thicknesses of layers, printing performance etc. of its slurry made have significant limitation for present high-end precision instrument; On the other hand, the conductive copper paste of the many employing printings of printed circuit board (PCB) in the past makes conducting wire, but it is easily oxidized to there is conductive copper paste, reduces the useful life of printed circuit board (PCB), and conductive copper paste can not be printed as meticulousr circuit.Therefore need the size of metal dust in research electrocondution slurry, shape, kind to realize the object reducing costs, improve conductance, improve printing accuracy.

Binding agent in conductive silver paste has a significant impact for the rate of finished products of circuit printing, such as the volatility etc. of viscosity, caking property, adhesive force, levelability, film forming, solvent all can impact the printing performance of circuit, there is pore, the phenomenons such as open circuit, also there will be glassy phase after organic substance has volatilized sometimes not yet to start to melt, the phenomenon causing conducting wire to come off from stock, makes conducting wire scrap, and therefore the performance need of organic binder bond improves.

A lot of inorganic binder adopts glass dust at present, glass dust is made up of the material such as metal oxide, silica, if fusing point is too high, also occur organic substance volatilized after glassy phase not yet start melt, the phenomenon causing the conducting wire obtained by conductive silver paste to come off from stock, makes conducting wire scrap; And a lot of containing harmful substances such as lead in current glass dust, unfavorable to environment, therefore need to develop the more excellent glass dust of performance.

Summary of the invention

The object of the present invention is to provide a kind of easily printing PCB silver slurry and preparation method thereof, this silver slurry good dispersion, good leveling property, easily prints, and the circuit of printing is continuous, clear, after drying, pore-free, crack, good with pcb board caking property, difficult drop-off, save the consumption of silver powder, but do not affect electric conductivity.

Technical scheme of the present invention is as follows:

One is printing PCB silver slurry easily, it is characterized in that being made up of the raw material of following weight portion: glass dust 12-16, thermosetting acrylic resin 7-9, CMC 2-4, butyl acetate 3-5, tributyl citrate 6-8, blown castor oil 0.4-0.7, N-phenyl-2-naphthylamine 1-2, cobalt acetate 0.2-0.5, wool grease 1-2, ethylene glycol monobutyl ether 5-7, dimethylbenzene 5-7,1-5nm copper powder 7-10,1-5 μm of silver powder 55-60, silver-colored coated TiO ₂the SiO that microballoon 2-4, silver are coated ₂microballoon 4-7;

Described glass dust is made up of the raw material of following weight portion: borax 15-17, Si0 ₂6-9, Bi ₂0 ₃20-25, A1 ₂0 ₃5-8, Li ₂0 3-5, MgO3-6, NaF2-4, Ti0 ₂3-6, ZnO4-7, K ₂o1-2, anoxic cerium oxide 1-2, nepheline powder 2-4, nanometer jade powder 2-5; Preparation method is: by borax, Si0 ₂, Bi20 ₃, A1 ₂0 ₃, Li ₂0, MgO, NaF, Ti0 ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1100-1400 DEG C of heat fused, vacuum defoamation is carried out after stirring, vacuum degree is 0.10-0.14MPa, and inclined heated plate is 6-9 minute, then pours in mould and shape, carry out shrend again, send into pulverizing in ball mill, sieve, obtain 2-6 μm of powder, then mix with nepheline powder, nanometer jade powder, to obtain final product.

The preparation method of described easy printing PCB silver slurry, is characterized in that comprising the following steps:

(1) by butyl acetate, tributyl citrate, wool grease, dimethylbenzene mixing, add thermosetting acrylic resin, CMC, be heated to 80-85 DEG C, be stirred to resin all to dissolve, add blown castor oil again to stir, filter with 400 object gauzes, removing impurity obtains organic carrier;

(2) ethylene glycol monobutyl ether is mixed with N-phenyl-2-naphthylamine, 1-5nm copper powder, under stirring at 5000-7000 rev/min, stir 10-20 minute, then add the coated TiO of silver ₂the SiO that microballoon, silver are coated ₂microballoon, stirs 10-20 minute, then adds 1-5 μm of silver powder, stirs 10-20 minute, then adds in organic carrier together with other residual componentss, mixing dispersion in ball mill, then ultrasonic disperse 4-6 minute obtains uniform slurry;

(3) slurry that step (2) obtains is carried out vacuum defoamation, vacuum degree is 0.05-0.07MPa, and inclined heated plate is 8-12 minute, then carries out grinding in three-high mill, rolling, reaches 3-5 micron, to obtain final product to silver slurry fineness.

Beneficial effect of the present invention

Silver slurry good dispersion of the present invention, good leveling property, easily prints, and the circuit of printing is continuous, clear, after drying, pore-free, crack, with the use of glass dust of the present invention, fusing point is low, good with pcb board caking property, difficult drop-off; By using the conductive fine powders such as copper powder, saving the consumption of silver powder, but not affected electric conductivity.

Embodiment

One is printing PCB silver slurry easily, is made up of the raw material of following weight portion (kilogram): glass dust 14, thermosetting acrylic resin 8, CMC 3, butyl acetate 4, tributyl citrate 7, blown castor oil 0.6, N-phenyl-2-naphthylamine 1.5, cobalt acetate 0.3, wool grease 1.5, ethylene glycol monobutyl ether 6, dimethylbenzene 6,3nm copper powder 8,3 μm of silver powder 57, silver-colored coated TiO ₂the SiO that microballoon 3, silver are coated ₂microballoon 6;

Described glass dust is made up of the raw material of following weight portion (kilogram): borax 16, Si0 ₂7, Bi ₂0 ₃23, A1 ₂0 ₃6, Li ₂04, MgO 5, NaF 3, Ti0 ₂4, ZnO 6, K ₂o 1.5, anoxic cerium oxide 1.5, nepheline powder 3, nanometer jade powder 3; Preparation method is: by borax, Si0 ₂, Bi20 ₃, A1 ₂0 ₃, Li ₂0, MgO, NaF, Ti0 ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1200 DEG C of heat fused, vacuum defoamation is carried out after stirring, vacuum degree is 0.13MPa, and inclined heated plate is 7 minutes, then pours in mould and shape, carry out shrend again, send into pulverizing in ball mill, sieve, obtain 3 μm of powder, then mix with nepheline powder, nanometer jade powder, to obtain final product.

The preparation method of described easy printing PCB silver slurry, comprises the following steps:

(1) by butyl acetate, tributyl citrate, wool grease, dimethylbenzene mixing, add thermosetting acrylic resin, CMC, be heated to 83 DEG C, be stirred to resin all to dissolve, add blown castor oil again to stir, filter with 400 object gauzes, removing impurity obtains organic carrier;

(2) ethylene glycol monobutyl ether is mixed with N-phenyl-2-naphthylamine, 3nm copper powder, stir 15 minutes under stirring at 6000 revs/min, then add the coated TiO of silver ₂the SiO that microballoon, silver are coated ₂microballoon, stirs 15 minutes, then adds 3 μm of silver powder, stirs 15 minutes, then adds in organic carrier together with other residual componentss, mixing dispersion in ball mill, then ultrasonic disperse obtains uniform slurry in 5 minutes;

(3) slurry that step (2) obtains is carried out vacuum defoamation, vacuum degree is 0.06MPa, and inclined heated plate is 10 minutes, then carries out grinding in three-high mill, rolling, reaches 4 microns, to obtain final product to silver slurry fineness.

Test data:

The mode of the silver slurry silk screen printing obtained by the present embodiment is printed onto in PCB, solidifies and forms conducting wire in 6 minutes, thus obtain conducting wire plate at being then warming up to 630 DEG C.The wiring width recording conducting wire is 0.6mm, average film thickness 5 μm, and wire distribution distance is 0.9mm, and resistivity is 4.5 × 10 ^-5Ω m.

Produce conducting wire plate 1000 pieces in batches in the manner described above, conducting wire is combined with PCB well, svelteness, continuously, has the conducting wire of 6 pieces of circuit boards to come off from stock, rate of finished products 99.4%.

Claims (2)

1. one kind is easily printed PCB silver slurry, it is characterized in that being made up of the raw material of following weight portion: glass dust 12-16, thermosetting acrylic resin 7-9, CMC 2-4, butyl acetate 3-5, tributyl citrate 6-8, blown castor oil 0.4-0.7, N-phenyl-2-naphthylamine 1-2, cobalt acetate 0.2-0.5, wool grease 1-2, ethylene glycol monobutyl ether 5-7, dimethylbenzene 5-7,1-5nm copper powder 7-10,1-5 μm of silver powder 55-60, silver-colored coated TiO ₂the SiO that microballoon 2-4, silver are coated ₂microballoon 4-7;

Described glass dust is made up of the raw material of following weight portion: borax 15-17, Si0 ₂6-9, Bi ₂0 ₃20-25, A1 ₂0 ₃5-8, Li ₂0 3-5, MgO3-6, NaF2-4, Ti0 ₂3-6, ZnO4-7, K ₂o1-2, anoxic cerium oxide 1-2, nepheline powder 2-4, nanometer jade powder 2-5; Preparation method is: by borax, Si0 ₂, Bi20 ₃, A1 ₂0 ₃, Li ₂0, MgO, NaF, Ti0 ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1100-1400 DEG C of heat fused, vacuum defoamation is carried out after stirring, vacuum degree is 0.10-0.14MPa, and inclined heated plate is 6-9 minute, then pours in mould and shape, carry out shrend again, send into pulverizing in ball mill, sieve, obtain 2-6 μm of powder, then mix with nepheline powder, nanometer jade powder, to obtain final product.

2. the preparation method of easy printing PCB silver slurry according to claim 1, is characterized in that comprising the following steps:

(1) by butyl acetate, tributyl citrate, wool grease, dimethylbenzene mixing, add thermosetting acrylic resin, CMC, be heated to 80-85 DEG C, be stirred to resin all to dissolve, add blown castor oil again to stir, and the viscosity controlling resin is at 3000-6000 centipoise, filter with 400 object gauzes, removing impurity obtains organic carrier;

(2) ethylene glycol monobutyl ether is mixed with N-phenyl-2-naphthylamine, 1-5nm copper powder, under stirring at 5000-7000 rev/min, stir 10-20 minute, then add the coated TiO of silver ₂the SiO that microballoon, silver are coated ₂microballoon, stirs 10-20 minute, then adds 1-5 μm of silver powder, stirs 10-20 minute, then adds in organic carrier together with other residual componentss, mixing dispersion in ball mill, then ultrasonic disperse 4-6 minute obtains uniform slurry;

(3) slurry that step (2) obtains is carried out vacuum defoamation, vacuum degree is 0.05-0.07MPa, and inclined heated plate is 8-12 minute, then carry out grinding in three-high mill, rolling, reach 3-5 micron to silver slurry fineness, viscosity is 10000-20000 centipoise, to obtain final product.