KR20060000784A - Composition of photosensitive conductor paste and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a composition of a photosensitive conductor paste and a method for manufacturing the same, comprising: (a) 55 to 75 wt% of a low-temperature cofired conductive metal powder; (b) 10 to 40% by weight of a vehicle comprising 2-hydroxy ethyl methacrylate and n-butyl methacrylate and comprising a solutiond organic binder having an acidic functional group, a monomer and a photoinitiator; (c) 0.1 to 5% by weight glass frit for plastic shrinkage control; (d) 0.5 to 1.5 weight percent dispersant; (e) It is a photosensitive conductor paste composition containing 1-8 weight% of organic solvents.

Therefore, the present invention provides a photosensitive conductor paste composition suitable for low temperature co-fired ceramic lamination process technology, when forming a fine lead in the green sheet with a paste, high resolution, less residues of line spacing after development, The plastic shrinkage behavior with the green sheet is matched to reduce the warpage of the substrate.

Photosensitive, conductor, paste, organic binder, resolution

Description

Composition of photosensitive conductor paste and method for manufacturing thereof {Composition of photosensitive conductor paste and method for manufacturing the same}             

1 is a flowchart for explaining a method of manufacturing a photosensitive conductor paste according to the present invention.

2 is an organic binder structure diagram of an embodiment according to the present invention

The present invention relates to a composition of a photosensitive conductor paste and a method of manufacturing the same. More particularly, the present invention provides a high resolution when forming fine wires in a green sheet, less residues in line spacing after development, and green. The present invention relates to a composition of a photosensitive conductor paste suitable for low temperature co-fired ceramic lamination process technology, in which plastic shrinkage behavior with a sheet is matched to reduce warpage of a substrate, and a method of manufacturing the same.

With the miniaturization of mobile communication devices, satellite broadcasting receivers, computers, and the like, miniaturization, complexation, high functionality, and high precision have been in progress for high frequency electronic components used in them. There is a need for a response to speeding up signal transmission.

To form the wiring pattern of the high frequency electronic component, a pattern is printed on an insulating substrate by using a conductive paste in which a metal powder such as silver, gold, copper, etc., and a vehicle made of an organic binder or an organic solvent are mixed, and the pattern is dried. By baking, the method of forming a predetermined wiring pattern is generally used.

Although the printing process using a screen is generally used for formation of such a thick-film lead, when it is desired to refine the thick-film lead by this method, it is difficult to form the width, the spacing, the pitch, etc. of the lead at 75 μm or less, or the yield is reduced. do.

And it is recognized that the wire width and the space | interval of at least about 50 micrometers are the miniaturization limits of the screen printing method.

On the other hand, Japanese Patent Laid-Open Nos. 5-287221, 8-227153 and the like have proposed a method of forming fine wires by a photolithography method using a photosensitive conductor paste.

In addition, US Patent Nos. 5,032,478, 5,049,480 and the like have been proposed for the composition of the photosensitive conductor face which can be developed by an aqueous solution and which can be fired in a non-oxidizing atmosphere.

In addition, Korean Patent No. 10-03512230 and Korean Patent Publication No. 2003-0006639 have also been proposed a photosensitive paste composition and a method of forming a fine wire using the same.

These methods apply a photosensitive paste composed of a conductive metal powder (or dielectric ceramic powder), an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain, a photoreactive compound, a photoinitiator, and the like to an insulating substrate, followed by exposure and drying. These are methods of patterning by photolithography including development.

On the other hand, multilayer ceramic chip or module technology using low temperature co-fired ceramic is becoming common for miniaturization and high functionalization of electronic components. In this case, it is preferable to use a green sheet composed of ceramic powder, an organic binder, a plasticizer, and a dispersant instead of an insulating substrate. is average.

At this time, the circuit pattern formation on the green sheet uses a screen printing process, and has a limitation in implementing wires similar to the resolution on the plastic substrate.

In order to overcome such a process limit for miniaturization and high integration, a photosensitive conductor paste product has been released, but there is a difficulty in practical application with low resolution or low co-firing consistency with the green sheet.

In particular, after the developing process, residues remain at the line intervals of the fine wires, resulting in problems such as deterioration in resolution or shrinkage rate during firing, resulting in warpage of the substrate after firing.

Accordingly, the present invention has been made to solve the above problems, the present invention has a high resolution when forming a fine wire in the green sheet, less residues of the line interval after development, firing with the green sheet SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive conductor paste composition and a method for producing the same, which are suitable for low temperature co-fired ceramic lamination process technology by matching shrinkage behavior to reduce warpage of a substrate.                         

A preferred aspect for achieving the above objects of the present invention,

(a) 55 to 75% by weight of the conductive metal powder for low temperature simultaneous firing;

(b) 10 to 40% by weight of a vehicle comprising 2-hydroxy ethyl methacrylate and n-butyl methacrylate and comprising a solutiond organic binder having an acidic functional group, a monomer and a photoinitiator;

(c) 0.1 to 5% by weight glass frit for plastic shrinkage control;

(d) 0.5 to 1.5 weight percent dispersant;

(e) A photosensitive conductor paste composition containing 1 to 8% by weight of an organic solvent is provided.

Another preferred aspect for achieving the above objects of the present invention is a solution of an organic binder, monomer containing 2-hydroxy ethyl methacrylate and n-butyl methacrylate, and having an acidic functional group. A first step of mixing the photoinitiator to produce a vehicle;

A second step of mixing a low temperature simultaneous firing conductive metal powder, a glass frit, and a dispersant into the vehicle made in the first step;

There is provided a method for producing a photosensitive conductor paste composition comprising a third step of adding a organic solvent to the mixture made in the second step to form a paste.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

The photosensitive conductor paste of the present invention comprises (a) low temperature co-conductive conductive metal powder, (b) an organic binder having an acidic functional group, (c) a photopolymerizable monomer, (d) a photoinitiator, and (e) plastic shrinkage control. It is characterized by containing a glass frit for (f) and an organic solvent.

In particular, the organic binder can be developed by an aqueous solution, and preferably has a composition that can be removed cleanly without leaving a residue in the line interval after development.

Hereinafter, the present invention will be described in detail.

(1) Conductive metal powder for low temperature simultaneous firing

The conductive powder used in the present invention is at least one metal powder selected from Ag, Cu, Au, Pd, Pt, Ni, the shape may be spherical, plate-like, rod-shaped, etc., in particular, the use of spherical powder with good dispersibility is preferable. .

The average particle diameter of these powders is in the range of 0.5 to 5 μm, preferably in the range of 1 to 3 μm.

The specific surface area is 0.2-4 m ² / g, the density is in the range 2-6 g / cc, more preferably the specific surface area is 0.5-2 m ² / g, and the density is 3-5 g / cc. .

The weight of the conductive metal powder in the total weight in the photosensitive conductor paste is preferably in the range of 55 to 75% by weight, more preferably in the range of 60 to 68%.

In this case, when the weight of the conductive metal powder is too small, the conductivity after the firing of the paste may be deteriorated, and the printing property may be degraded. In particular, the photosensitive materials may be increased, and thus the resolution may be reduced.

In addition, if the weight ratio of the conductive metal powder is too large than the above-mentioned range, the plastic shrinkage ratio of the conductive metal powder and the green sheet may be inconsistent, resulting in warpage or cracking of the substrate. In particular, the photosensitive materials may be too small, resulting in poor pattern formation. .

(2) organic binder

The organic binder used in the present invention is a copolymer containing methyl methacrylate (MMA) and methacrylic acid (MAA) as main components and containing a complement.

The weight of methyl methacrylate in the total weight of the organic binder is preferably in the range of 65 to 85% by weight, and the weight of the methacrylic acid is preferably in the range of 10 to 20% by weight.

In addition, as a complement, 2-hydroxy ethyl methacrylate and n-butyl methacrylate, 2-hydroxy ethyl methacrylate in the total weight of the organic binder is 2 to 10% by weight, n-butyl methacrylate is 2 to 15% by weight.

These copolymers are binder polymers that can be developed by an aqueous solution containing a small amount of Na ₂ CO ₃ .

The acid value of the organic binder is 40 ~ 60 mgKOH / g, the solid content in the total weight of the organic binder is 30 to 50%, the acid value of the solid content is 90 ~ 120 mgKOH / g, the molecular weight of the solid content is 5000 to 50000 print Suitable for characteristics and high resolution implementations.

In the total weight of the vehicle, the organic binder is 65 to 85% by weight, which is suitable for adhesion with the green sheet and realizing fine wire resolution.

(3) monomers and photoinitiators

The monomer used in the present invention is a material containing a carbon double bond, and serves to form a hardened region in the photosensitive paste by polymerizing a double bond into a single bond by radicals excited by ultraviolet rays.

As the monomer, an acrylic ester selected from trimethylolpropane triacrylate, trimethylolpropane ethoxylated triacrylate, pentaerythritol tri-acrylate or pentaerythritol tetra-acrylate may be preferably used. The weight of the monomer in the total weight is preferably 10 to 30% by weight.

The photoinitiator used in the present invention is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (TPO), which is one of acrylphosphine oxides, which is known to have excellent absorption characteristics against ultraviolet rays of 365 nm wavelength. The content is preferably 1 to 10% by weight based on the total amount of the vehicle.

Here, the photoinitiator is excited by ultraviolet rays to form radicals, and serves to initiate the polymerization of the monomers.

(4) glass frit

The glass frit mitigates the plastic shrinkage mismatch between the green sheet and the paste, and enhances the adhesion between the ceramic and the paste during firing.

The glass frit used in the present invention may be TG4 or TG5 manufactured by Temen Technology Co., and its content is preferably 0.1 to 5% by weight based on the total weight of the photosensitive conductor paste composition.

Here, if the glass frit is too small, there is a risk of warpage or cracking due to shrinkage mismatch, and if too large, the glass frit may increase the sheet resistance of the conductive wire after firing, thereby degrading electrical characteristics.

(5) organic solvents and other additives

Organic solvents that may be used in the preparation of the paste for viscosity control may be used alone or in combination of two or more of terpinol, butyl carbitol, butyl carbitol acetate, ethyl carbitol acetate, and the like.

Herein, the content of the organic solvent is preferably 1 to 8% by weight based on the total weight of the photosensitive conductor paste composition.

As other additives, a dispersant used for proper dispersion of the conductor powder, a lubricant for improving printing properties, a plasticizer for flexibility, a leveling agent for flattening, and the like may be used. As a dispersant, oleic acid from Sigma Aldrich was used as lubricant.

1 is a flowchart for explaining a method for producing a photosensitive conductor paste according to the present invention, firstly, a solution-organized organic compound containing 2-hydroxy ethyl methacrylate and n-butyl methacrylate and having an acidic functional group. A binder, monomer and photoinitiator are mixed to make a vehicle. (S10 step)

Thereafter, the conductive metal powder for low temperature simultaneous firing, the glass frit and the dispersant are mixed and mixed in the vehicle made in step S10.

Finally, an organic solvent is added to the mixture made in step S20 to make a paste.

Here, the step S30 is to put the mixture made in the second step in a three-roll mill, milling 20 to 30 minutes while adding an organic solvent and lubricant to make a paste.

In order to make a fine wire using the photosensitive conductor paste thus prepared, first, the photosensitive conductor paste is stirred and defoamed with a high speed mixer.

At this time, for proper application of the pre-exposure paste, the viscosity of the paste preferably has a range of 30,000 to 100,000 centipoise.

Thereafter, the photosensitive conductor paste composition was coated on a green sheet by printing, dried in an oven at 80 ° C. for about 10 minutes, and then a mask or film having a fine conductive pattern formed thereon was placed on the dried paste and 500 to 1500 mJ / Exposure is performed by irradiation with cm ² ultraviolet rays.

After removing the mask, the exposed paste is etched using a spray developer using an aqueous solution in which 1% by weight of Na ₂ CO ₃ is dissolved as a developer to form a fine lead pattern.

The green sheet on which the fine lead pattern is formed is laminated together with several other dummy sheets and baked at a temperature of 850 to 900 ° C. for 10 to 30 minutes, thereby forming a thick film fine lead on or inside the low temperature co-fired ceramic substrate. To complete.

According to the composition and the manufacturing process, it is possible to obtain a fired substrate having a fine pattern having a line width of about 15 μm and a line interval of about 15 μm, no residue of line intervals, and good shrinkage matching with low temperature co-fired ceramics.

Therefore, the present invention can increase the resolution of the thick film lead than the conventional screen printing method, and it is possible to manufacture the photosensitive conductor paste capable of simultaneous firing by matching the shrinkage rate with the low temperature simultaneous firing ceramic green sheet.

In addition, by removing the residue between the line has the advantage that can further increase the resolution of the conductive wire than the conventional photosensitive paste.

The conductive powder, acrylic binder, monomer, photoinitiator, glass frit, and the like used in the examples according to the present invention described below are summarized in Table 1.

Item Ingredient Specification / Model Remarks Conductive powder Ag D50 ~ 1 ㎛ Degussa  Acrylic binder  Methyl methacrylate (MMA) methacrylic acid (MAA) (solid acid value 111, molecular weight 19000, Tg 117 ° C.) 83 wt% 17 wt%                                              KB-P1 -  Methyl methacrylate (MMA) methacrylic acid (MAA) 2-hydroxy ethyl methacrylate (HEMA) (solid acid value 111, molecular weight 30000, Tg 109 ° C.) 70.5 wt% 17 wt% 12.5 wt%                                              KB-P2 -  Methyl methacrylate (MMA) methacrylic acid (MAA) 2-hydroxy ethyl methacrylate (MEMA) n-butyl methacrylate (nBMA) (solid acid value 111, molecular weight 15600, Tg 103 ° C.) 67.3 wt% 17.1 wt% 6.7 wt%                                                  8.9 wt%                                              KB-P3 -  Monomer Trimethylolpropane ethoxylated triacrylate (TMPEOTA) M310 Miwon Corporation Photoinitiator 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide TPO Miwon Corporation Glass frit - TG4 Temen Technology Solvent α-Terpineol / BCA (mixed) 2: 1 - slush Oleic acid - - Dispersant - PS-2 - Green sheet LTCC Powder Dupont 9599 Self-made sheet

Comparative Example 1

Table 2 shows the composition of the photosensitive conductor paste of Comparative Example 1 for comparison with the Example according to the present invention, and shows the weight (g) of each component when the total photosensitive conductor paste total weight is 107.7g.

Item Ingredient Weight (g) Conductor powder Ag 70 Acrylic binder KB-P1 24 Monomer M310 6 Photoinitiator TPO 1.8 Solvent α-Terpineol / BCA (mixed) 5 slush Oleic acid 0.2 Dispersant PS-2 0.7

In Comparative Example 1, KB-P1 copolymerized with an acrylic binder was used as a basic composition. A paste was prepared for a composition without adding glass frit, and a fine wire pattern was prepared.

After development, a pattern of 20 μm or less fell off from the green sheet, and cracks were found inside the micro lead due to the shrinkage mismatch between the lead and the substrate after firing.

After firing, the highest resolution of line width / line spacing was 25 µm / 25 µm on average.

Comparative Example 2

Table 3 shows the composition of the photosensitive paste of Comparative Example 2 for comparison with the Example according to the present invention, and shows the weight (g) of each component when the total photosensitive conductor paste total weight is 107.7g.

Item Ingredient Weight (g) Conductor powder Ag 68 Acrylic binder KB-P2 24 Monomer M310 6 Photoinitiator TPO 1.8 Glass frit TG4 2 Solvent α-Terpineol / BCA (mixed) 5 slush Oleic acid 0.2 Dispersant PS-2 0.7

In Comparative Example 2, KB-P2 having HEMA added to the basic composition as an acrylic binder was used, a paste was prepared for the glass frit-added composition, and a fine lead pattern was prepared.

The adhesion to the green sheet was improved, and after development, the fine pattern did not fall off from the green sheet, but many residues were found in the line spacing and the resolution was slightly reduced (line width and line spacing).

In addition, it appears that the adhesion force with the green sheet is increased by the action of the OH group possessed by HEMA, and may be considered to have exceeded an appropriate level.

In addition, the cracks generated inside the fine wire after firing were alleviated by the glass frit.

In addition, the maximum width / line spacing resolution after firing averaged 30 µm / 20 µm.

EXAMPLE

Table 4 shows the composition of the photosensitive paste of the embodiment according to the present invention, and shows the weight (g) of each component when the total photosensitive conductor paste total weight is 107.7 g.

Item Ingredient Weight (g) Conductor powder Ag 68 Acrylic binder KB-P3 24 Monomer M310 6 Photoinitiator TPO 1.8 Glass frit TG4 2 Solvent α-Terpineol / BCA (mixed) 5 slush Oleic acid 0.2 Dispersant PS-2 0.7

In the embodiment of the present invention using the organic binder KB-P3 of the structure as shown in Figure 2 to add the HEMA and nBMA to the basic composition at the same time as the acrylic binder, to prepare a paste for the composition to which glass frit is added, The pattern was produced.

The adhesion to the green sheet is good, and after development, the resolution of the fine pattern is also improved, so that a 20 μm wire pattern on the mask is stably implemented.

By slightly reducing the amount of HEMA, the adhesion to the green sheet is adjusted to an appropriate level, and the addition of nBMA softens the film, which appears to help the development.

After firing with the glass frit, no cracks occurred in the fine conductive wires.

In addition, after firing, the highest resolution of line width / line spacing was 15 µm / 15 µm on average.

As a result, when 2-hydroxy ethyl methacrylate (MEMA) and n-butyl methacrylate (nBMA) are contained in the organic binder as in the embodiment of the present invention, when the fine wire is formed from the paste, cracks are formed. It is not generated, the adhesion to the green sheet is excellent, and the resolution can be excellent.

As described above, the present invention is to prepare a photosensitive conductor paste composition suitable for low temperature co-fired ceramic lamination process technology, when forming a fine conductive wire in the green sheet with a paste, high resolution, residues of the line interval after development There is little, and the plastic shrinkage behavior with the green sheet is matched, thereby reducing the warpage of the substrate.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (15)

(a) 55 to 75% by weight of the conductive metal powder for low temperature simultaneous firing; (b) 10 to 40% by weight of a vehicle containing 2-hydroxy ethyl methacrylate and n-butyl methacrylate and comprising an acidified functional group having a solutiond organic binder, a monomer and a photoinitiator; (c) 0.1 to 5% by weight glass frit for plastic shrinkage control; (d) 0.5 to 1.5 weight percent dispersant; (e) The photosensitive conductor paste composition containing 1-8 weight% of organic solvents. The method of claim 1, At the vehicle total weight, The organic binder is 65 to 85% by weight, the monomer is 10 to 30% by weight, the photoinitiator is a photosensitive conductor paste composition, characterized in that 1 to 10% by weight. The method according to claim 1 or 2, In the total weight of the organic binder, Methyl methacrylate is 65-85 wt%, methacrylic acid is 10-20 wt%, 2-hydroxy ethyl methacrylate 2-10 wt%, n-butyl methacrylate 2-15 wt% The photosensitive conductor paste composition characterized by the above-mentioned. The method according to claim 1 or 2, The organic binder, Acid number is 40-60 mgKOH / g, Solid content in the total weight of the organic binder is 30 to 50%, the acid value of the solid content is 90 to 120 mgKOH / g, the molecular weight of the solid content is 5000 to 50000, the photosensitive conductor paste composition. The method according to claim 1 or 2, The monomer is, A photosensitive conductor paste composition comprising any one selected from trimethylolpropane triacrylate, trimethylolpropane ethoxylated acrylate, pentaerythritol tri-acrylate, and pentaerythritol tetra-acrylate. The method according to claim 1 or 2, The conductive metal powder Selected from Ag, Cu, Au, Pd, Pt and Ni, The average particle diameter is 0.5-5 탆, Specific surface area is 0.2-4 m ² / g, The photosensitive conductor paste composition of which density is 2-6 g / cc. The method according to claim 1 or 2, The photoinitiator, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. The photosensitive conductor paste composition characterized by the above-mentioned. The method of claim 1, In the photosensitive conductor paste composition, A photosensitive conductor paste composition comprising an additive consisting of a lubricant, a plasticizer, and a leveling agent for printing properties, in an amount of 0.1 to 0.5% by weight. A first step of mixing a solution comprising an organic functional group, a monomer and a photoinitiator containing 2-hydroxy ethyl methacrylate and n-butyl methacrylate to form a vehicle; A second step of mixing a low temperature simultaneous firing conductive metal powder, a glass frit, and a dispersant into the vehicle made in the first step; A method for producing a photosensitive conductor paste composition comprising a third step of making a paste by adding an organic solvent to the mixture made in the second step. The method of claim 9, The third step, Method for producing a photosensitive conductor paste composition characterized in that the mixture made in the second step in a three-roll mill, milling for 20 to 30 minutes while adding an organic solvent and a lubricant to make a paste. The method of claim 9, In the total weight of the organic binder, Methyl methacrylate is 65-85 wt%, methacrylic acid is 10-20 wt%, 2-hydroxy ethyl methacrylate 2-10 wt%, n-butyl methacrylate 2-15 wt% The manufacturing method of the photosensitive conductor paste composition characterized by the above-mentioned. The method according to claim 9 or 11, At the vehicle total weight, The organic binder is 65 to 85% by weight, the monomer is 10 to 30% by weight, the photoinitiator is a method for producing a photosensitive conductor paste composition, characterized in that 1 to 10% by weight. The method according to claim 9 or 11, The organic binder, Acid number is 40-60 mgKOH / g, Solid content in the total weight of the organic binder is 30 to 50%, the acid value of the solid content is 90 ~ 120 mgKOH / g, the molecular weight of the solid content is 5000 ~ 50000 The method for producing a photosensitive conductor paste composition. The method according to claim 8 or 11, wherein The monomer is, Trimethylolpropane triacrylate, trimethylolpropane ethoxylated acrylate, pentaerythritol tri-acrylate, pentaerythritol tetra-acrylate of any one of the photosensitive conductor paste composition Manufacturing method. The method according to claim 8 or 11, wherein The photoinitiator, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

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