CN104036845A - PCB (Printed Circuit Board) silver paste and manufacturing method thereof - Google Patents

Abstract

The invention provides a PCB silver paste. The PCB silver paste is manufactured by the following raw material by weight, glass powder 8 to 10, 10 to 15mum flake silver powder 40 to 50, nanoscale flake silver powder 15 to 20, silver coated nickel powder 10 to 15, bisphenol F-type epoxy resin 8 to 12, isopropyl myristate 1 to 2, tartaric acid 1 to 2, sebacic acid 2 to 3, nano chitin 0.3 to 0.5, polyvinyl alcohol 1 to 2, terpineol 4 to 6, 2-methyl imidazole 0.3 to 0.5, butylcarbitol 4 to 6, methyl cellosolve 3 to 5, and butyl carbitol acet 3 to 5. According to the silver paste of the invention, through using flake silver powder different in particle sizes, contact is tight, and conductive performance is good; the cost is saved through using the silver coated nickel powder; the production technology is unique, and silver powder can be prevented from being aggregated to influence the conductvie performance; and the printing performance is good, the circuit board yield is high, falling is not easy, and the use time is long.

Description

A kind of PCB printed circuit board (PCB) silver slurry and preparation method thereof

Technical field

The invention belongs to electric slurry technical field, relate in particular to a kind of PCB printed circuit board (PCB) silver slurry and preparation method thereof.

Background technology

In modern microelectronics industry, people require more and more higher to electronic devices and components, produce and adopt procedures, standardization to carry out reducing costs more, printed circuit board (PCB) (PCB) is exactly that this demand that is applicable to microelectronics industry is born, the electric slurries such as corresponding conductor paste, electrode slurry, dielectric paste and resistance slurry with regard to the new requirement of demand, grout slurry and printed circuit board (PCB) (PCB) match, and the research of 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., and inorganic binder is as glass powder, oxide powder etc., organic binder bond, other solvent and additive.Conventionally, function in electric slurry plays electric action mutually, have good electric conductivity, generally by metal dust or noble metal powder, is served as, 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 fixedly electric slurry and, to base material, generally by oxide powder and glass powder, is served as, but this composition is lower at the proportion of electric slurry, and what have does not even have; Organic binder bond mainly plays a part to make slurry to have certain shape, is easy to printing or coating, mainly containing macromolecule resin, little molecule resin etc. serves as, along with this part effect in electric slurry of the progress of chemical industry technology is more and more outstanding, especially when being applied to silk screen printing, the composition that changes organic binder bond just can change the printing of electric slurry, dry, sintering character.

In existing electric slurry field, it is high that silver is that slurry has conductance, and 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, cost is higher, and the silver powder major part in existing silver paste is micron-sized powder, and the thicknesses of layers of the slurry that it is made, printing performance etc. have significant limitation for present high-end precision instrument; On the other hand, printed circuit board (PCB) adopted printing conductive copper slurry to make conducting wire more in the past, but it is easily oxidized to exist conductive copper paste, and in the useful life of having reduced printed circuit board (PCB), conductive copper paste can not be printed as meticulousr circuit.Therefore size, shape, the kind that need to study metal dust in electrocondution slurry reduce costs, improve conductance to realize, improve the object of printing accuracy.

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

At present a lot of inorganic binders adopt glass dust, glass dust is made by materials such as metal oxide, silica, if fusing point is too high, also occur organic substance volatilized after glassy phase not yet start to melt, the phenomenon that the conducting wire that causes being obtained by conductive silver paste comes off from stock, scraps conducting wire; And in current glass dust, much contain the harmful substances such as plumbous, and unfavorable to environment, therefore need to develop the glass dust that performance is more excellent.

Summary of the invention

The object of the present invention is to provide a kind of PCB printed circuit board (PCB) silver slurry and preparation method thereof, this silver slurry good conductivity, has saved cost, and printing performance is good, and circuit board rate of finished products is high, difficult drop-off, and service time is long.

Technical scheme of the present invention is as follows:

A kind of PCB printed circuit board (PCB) silver slurry, is characterized in that being made by the raw material of following weight portion: glass dust 8-10,10-15 μ m flake silver powder 40-50, nano-grade silver powder 15-20, silver coated nickel powder 10-15, bisphenol f type epoxy resin 8-12, isopropyl myristate 1-2, tartaric acid 1-2, decanedioic acid 2-3, nano-chitosan 0.3-0.5, polyvinyl alcohol 1-2, terpinol 4-6, glyoxal ethyline 0.3-0.5, fourth carbitol 4-6, methyl cellosolve 3-5, fourth carbitol acetate 3-5;

Described glass dust is made by the raw material of following weight portion: borax 15-17, SiO ₂6-9, Bi ₂o ₃20-25, A1 ₂o ₃5-8, Li ₂o 3-5, MgO3-6, NaF2-4, TiO 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, SiO ₂, Bi ₂o ₃, A1 ₂o ₃, Li ₂o, MgO, NaF, TiO ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1100-1400 ℃ of heat fused, after stirring, carry out vacuum defoamation, vacuum degree is 0.10-0.14MPa, and the deaeration time is 6-9 minute, then pours in mould and shape, carry out again shrend, send in ball mill and pulverize, sieve, obtain 2-6 μ m powder, then mix with nepheline powder, nanometer jade powder, obtain.

The preparation method of described PCB printed circuit board (PCB) silver slurry, is characterized in that comprising the following steps:

(1) terpinol, fourth carbitol, polyvinyl alcohol, methyl cellosolve, fourth carbitol acetate, decanedioic acid, isopropyl myristate are mixed, add bisphenol f type epoxy resin, be heated to 80-83 ℃, being stirred to resin all dissolves, add again nano-chitosan to stir, with 500 object gauzes, filter, remove impurity and obtain organic carrier;

(2) glass dust, tartaric acid are mixed, under 5000-7000 rev/min of stirring, add 10-15 μ m flake silver powder, stir 10-20 minute, add again nano-grade silver powder, silver coated nickel powder, stir 10-20 minute, then add in organic carrier together with other residual componentss, in ball mill, mix and disperse 10-15 minute, ultrasonic dispersion 8-12 minute, obtains uniform slurry again;

(3) slurry step (2) being obtained carries out vacuum defoamation, and vacuum degree is 0.04-0.06MPa, and the deaeration time is 8-12 minute, then in three-high mill, grinds, rolling, reaches 3-5 micron to silver slurry fineness, obtains.

Beneficial effect of the present invention

Silver slurry of the present invention, by using the flake silver powder of different-grain diameter, makes contact closely, good conductivity; By using silver coated nickel powder, saved cost; The production technology of the present invention's silver slurry is unique, can prevent silver powder reunion and affect conductivity; Silver slurry printing performance of the present invention is good, and circuit board rate of finished products is high, difficult drop-off, and service time is long.

Embodiment

A kind of PCB printed circuit board (PCB) silver slurry, by following weight portion (kilogram) raw material make: glass dust 9,13 μ m flake silver powders 45, nano-grade silver powder 18, silver coated nickel powder 13, bisphenol f type epoxy resin 10, isopropyl myristate 1.5, tartaric acid 1.5, decanedioic acid 2.5, nano-chitosan 0.4, polyvinyl alcohol 1.5, terpinol 5, glyoxal ethyline 0.4, fourth carbitol 5, methyl cellosolve 4, fourth carbitol acetate 4;

Described glass dust by following weight portion (kilogram) raw material make: borax 16, SiO ₂7, Bi ₂o ₃23, A1 ₂o ₃6, Li ₂o 4, MgO 5, NaF 3, TiO ₂4, ZnO 6, K ₂o 1.5, anoxic cerium oxide 1.5, nepheline powder 3, nanometer jade powder 3; Preparation method is: by borax, SiO ₂, Bi ₂o ₃, A1 ₂o ₃, Li ₂o, MgO, NaF, TiO ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1200 ℃ of heat fused, after stirring, carry out vacuum defoamation, vacuum degree is 0.13MPa, and the deaeration time is 7 minutes, then pours in mould and shape, carry out again shrend, send in ball mill and pulverize, sieve, obtain 3 μ m powder, then mix with nepheline powder, nanometer jade powder, obtain.

The preparation method of described PCB printed circuit board (PCB) silver slurry, comprises the following steps:

(1) terpinol, fourth carbitol, polyvinyl alcohol, methyl cellosolve, fourth carbitol acetate, decanedioic acid, isopropyl myristate are mixed, add bisphenol f type epoxy resin, be heated to 82 ℃, being stirred to resin all dissolves, add again nano-chitosan to stir, with 500 object gauzes, filter, remove impurity and obtain organic carrier;

(2) glass dust, tartaric acid are mixed, under 6000 revs/min of stirrings, add 13 μ m flake silver powders, stir 15 minutes, add again nano-grade silver powder, silver coated nickel powder, stir 15 minutes, then add in organic carrier together with other residual componentss, in ball mill, mix and disperse 13 minutes, ultrasonic dispersion is 10 minutes again, obtains uniform slurry;

(3) slurry step (2) being obtained carries out vacuum defoamation, and vacuum degree is 0.05MPa, and the deaeration time is 10 minutes, then in three-high mill, grinds, rolling, reaches 4 microns to silver slurry fineness, obtains.

Test data:

The silver slurry that the present embodiment is obtained is printed onto on PCB circuit board by the mode of silk screen printing, is then warming up at 630 ℃ and solidifies and form conducting wire in 6 minutes, thereby obtain conducting wire plate.The wiring width that records conducting wire is 0.5mm, average film thickness 5 μ m, and wire distribution distance is 0.7mm, resistivity is 4.8 * 10 ^-5Ω m.

Producing in the manner described above 1000 of conducting wire plates in batches, is combined well with PCB circuit board in conducting wire, and svelteness continuously, has the conducting wire of 2 circuit boards to come off from stock, rate of finished products 99.8%.

Claims (2)

1. a PCB printed circuit board (PCB) silver slurry, is characterized in that being made by the raw material of following weight portion: glass dust 8-10,10-15 μ m flake silver powder 40-50, nano-grade silver powder 15-20, silver coated nickel powder 10-15, bisphenol f type epoxy resin 8-12, isopropyl myristate 1-2, tartaric acid 1-2, decanedioic acid 2-3, nano-chitosan 0.3-0.5, polyvinyl alcohol 1-2, terpinol 4-6, glyoxal ethyline 0.3-0.5, fourth carbitol 4-6, methyl cellosolve 3-5, fourth carbitol acetate 3-5;

Described glass dust is made by the raw material of following weight portion: borax 15-17, SiO ₂6-9, Bi ₂o ₃20-25, A1 ₂o ₃5-8, Li ₂o 3-5, MgO3-6, NaF2-4, TiO 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, SiO ₂, Bi ₂o ₃, A1 ₂o ₃, Li ₂o, MgO, NaF, TiO ₂, ZnO, K ₂o, anoxic cerium oxide mix, put into crucible and become liquid 1100-1400 ℃ of heat fused, after stirring, carry out vacuum defoamation, vacuum degree is 0.10-0.14MPa, and the deaeration time is 6-9 minute, then pours in mould and shape, carry out again shrend, send in ball mill and pulverize, sieve, obtain 2-6 μ m powder, then mix with nepheline powder, nanometer jade powder, obtain.

2. the preparation method that PCB printed circuit board (PCB) silver according to claim 1 is starched, is characterized in that comprising the following steps:

(1) terpinol, fourth carbitol, polyvinyl alcohol, methyl cellosolve, fourth carbitol acetate, decanedioic acid, isopropyl myristate are mixed, add bisphenol f type epoxy resin, be heated to 80-83 ℃, being stirred to resin all dissolves, add again nano-chitosan to stir, with 500 object gauzes, filter, remove impurity and obtain organic carrier;

(2) glass dust, tartaric acid are mixed, under 5000-7000 rev/min of stirring, add 10-15 μ m flake silver powder, stir 10-20 minute, add again nano-grade silver powder, silver coated nickel powder, stir 10-20 minute, then add in organic carrier together with other residual componentss, in ball mill, mix and disperse 10-15 minute, ultrasonic dispersion 8-12 minute, obtains uniform slurry again;

(3) slurry step (2) being obtained carries out vacuum defoamation, and vacuum degree is 0.04-0.06MPa, and the deaeration time is 8-12 minute, then in three-high mill, grinds, rolling, reaches 3-5 micron to silver slurry fineness, obtains.