Negative thick film photolithography slurry and preparation method thereof

Abstract

The invention discloses a negative thick film photolithography slurry and a preparation method thereof, belonging to the technical field of electronic slurry. The negative thick film photolithography slurry comprises the following mass percentage combination: 75-80% conductive metal phase, 15-25% photosensitive organic carrier, 0.5-2% bonding phase; the bonding phase comprises glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additives is 1: (0.1-0.8); the inorganic additives comprise bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1: (0.5-2): (0.2-1). The negative thick film photolithography slurry has excellent conductivity, bonding force and acid resistance.

Description

Technical Field

[0001] The invention relates to the technical field of electronic paste, in particular to a negative thick film photolithography paste and a preparation method thereof. Background Art

[0002] PI-TF (Photoimageable Thick-film Technology) is a new type of photolithography technology that combines photolithography processes such as exposure and development with traditional thick-film printing processes. It is a process for forming thick-film circuits through photolithography. It can achieve the layout of ultra-high precision and ultra-fine wires, and realize the miniaturization and high-density of advanced electronic components and semiconductor packaging. It has huge application value and market prospects.

[0003] In addition to the requirements of high-precision wiring, some precision components need to be thickened by electroless nickel, copper, silver, tin, etc. after metallization to improve electrical performance; some require electroless nickel and gold plating to improve solderability and chemical aging resistance; because the electroless plating process conditions are very harsh and require a long time of immersion in a high temperature (80-90°C) and strong acid environment, conventional metallization pastes are difficult to withstand this electroless plating process. After electroless plating, the adhesion of the circuit pattern is greatly reduced, and it may even peel and fall off; therefore, the industry urgently needs a negative thick film photolithography metallization paste that can use photolithography technology to achieve ultra-high precision and ultra-fine wire layout, and is resistant to chemical plating. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a negative thick film photolithography slurry and a preparation method thereof, which have excellent electrical conductivity, adhesion and acid resistance.

[0005] To achieve the above object, in a first aspect of the present invention, the present invention provides a negative thick film photolithography slurry, comprising the following combination by mass percentage: 75-80% conductive metal phase, 15-25% photosensitive organic carrier, 0.5-2% binder phase;

[0006] The bonding phase includes glass powder and inorganic additives;

[0007] The mass ratio of the glass powder to the inorganic additive is 1:(0.1-0.8);

[0008] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1: (0.5-2): (0.2-1).

[0009] As a preferred embodiment of the present invention, the composition comprises the following mass percentages: 70-80% conductive metal phase, 18-25% photosensitive organic carrier, and 0.8-2% bonding phase.

[0010] As a preferred embodiment of the present invention, the conductive metal phase includes a first precious metal powder, a second precious metal powder, and a third precious metal powder; the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is 1: (1-4): (2-6);

[0011] The first precious metal powder, the second precious metal powder, and the third precious metal powder include one of silver powder, gold powder, silver-palladium powder, silver-coated copper powder, and platinum powder;

[0012] The first precious metal powder, the second precious metal powder and the third precious metal powder are the same precious metal powder.

[0013] As a preferred embodiment of the present invention, the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is 1:(1-3):(2-5).

[0014] As a preferred embodiment of the present invention, the average particle size of the first precious metal powder is 0.5-2 μm; the average particle size of the second precious metal powder is 4-8 μm; and the average particle size of the third precious metal powder is 10-20 μm.

[0015] As a preferred embodiment of the present invention, the photosensitive organic carrier comprises the following components in percentage by mass: 30-50% photosensitive resin, 2-8% photoinitiator, 0.2-1% dispersant, 0.2-0.8% leveling agent, 0.2-0.6% defoamer, 0.1-0.5% thixotropic agent, 4-20% diluent, and 30-50% solvent;

[0016] The molecular structure of the photosensitive resin contains a photosensitive group and an alkali-soluble group, and the acid value of the photosensitive resin is 25-200 mgKOH / g.

[0017] As a preferred embodiment of the present invention, the photosensitive resin includes at least one of an alkali-soluble acrylic resin, an alkali-soluble epoxy acrylic resin, and an alkali-soluble polyurethane-modified acrylic resin.

[0018] As a preferred embodiment of the present invention, the photoinitiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, thiopropoxythioxanthone and diphenylacetone; and / or

[0019] The dispersant comprises at least one of a polyester dispersant and a polyether dispersant; and / or

[0020] The leveling agent comprises at least one of acrylated polysiloxane, polyether-modified polysiloxane, polysiloxane-polyether copolymer, and polysiloxane; and / or

[0021] The defoaming agent comprises at least one of tributyl phosphate, trimethylsiloxane, polyether, polyacrylate, and silicone resin; and / or

[0022] The thixotropic agent includes at least one of fumed silica and amide wax.

[0023] As a preferred embodiment of the present invention, the diluent includes at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and hydroxyethyl methacrylate; and / or

[0024] The solvent includes at least one of dimethyl oxalate, diethyl oxalate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, diethyl glutarate, dipropyl adipate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate.

[0025] In a second aspect of the present invention, the present invention provides a method for preparing a negative thick film photolithography slurry, comprising the following steps:

[0026] The photosensitive resin, the photoinitiator, the dispersant, the leveling agent, the defoaming agent, the active diluent and the thixotropic agent are mixed uniformly to obtain a mixture, and the mixture is added into a solvent preheated to 50-60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0027] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry.

[0028] The beneficial effects of the present invention are as follows: (1) The present invention combines the conductive metal phase, the photosensitive organic carrier and the adhesive phase as described above to obtain a phase having excellent conductive properties, adhesive force and acid resistance, and excellent stability. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0031] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0032] In the present invention, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0033] The reagents or instruments used in the present invention without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0034] The embodiment of the present invention provides a negative thick film photolithography slurry, comprising the following combination by mass percentage: 75-80% conductive metal phase, 15-25% photosensitive organic carrier, and 0.5-2% bonding phase;

[0035] The bonding phase includes glass powder and inorganic additives;

[0036] The mass ratio of the glass powder to the inorganic additive is 1:(0.1-0.8);

[0037] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1: (0.5-2): (0.2-1).

[0038] The present invention combines the conductive metal phase, the photosensitive organic carrier and the bonding phase according to the above-mentioned specific mass ratio to obtain a film having excellent conductive performance, bonding force and acid resistance and excellent stability.

[0039] Among them, the addition of inorganic additives can help adhesion and further improve the bonding strength.

[0040] In one embodiment, the negative thick film photolithography slurry comprises the following combination in mass percentage: 70-80% conductive metal phase, 18-25% photosensitive organic carrier, and 0.8-2% binder phase.

[0041] In one embodiment, the conductive metal phase includes a first precious metal powder, a second precious metal powder, and a third precious metal powder; the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is 1: (1-4): (2-6);

[0042] The first precious metal powder, the second precious metal powder, and the third precious metal powder include one of silver powder, gold powder, silver-palladium powder, silver-coated copper powder, and platinum powder;

[0043] The first precious metal powder, the second precious metal powder and the third precious metal powder are the same precious metal powder.

[0044] In one embodiment, the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is 1:(1-3):(2-5).

[0045] In one embodiment, the average particle size of the first precious metal powder is 0.5-2 μm; the average particle size of the second precious metal powder is 4-8 μm; and the average particle size of the third precious metal powder is 10-20 μm.

[0046] The present invention selects three kinds of precious metal powders with different particle sizes, combines them in a specific mass ratio, uses them together, and strictly controls their average particle size, wherein the second precious metal powder of 4-8 μm can be effectively filled between the third precious metal powder of 10-20 μm, and the remaining pores are filled with the finer first precious metal powder (0.5-2 μm), which can effectively increase the number of conductive paths, improve the conductivity, and make the sintered metal layer denser, with better stability and mechanical properties, and have a stronger barrier effect.

[0047] The inventors have discovered that the mass ratio and particle size of the first precious metal powder, the second precious metal powder, and the third precious metal powder all have a certain influence on the performance. By controlling the mass ratio and particle size of the first precious metal powder, the second precious metal powder, and the third precious metal powder within the scope of the present invention, the effect is better, and the powder has better conductivity, stability, and mechanical properties.

[0048] If the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is not within the scope of the present invention, it will either lead to poor stacking of the precious metal powders and poor density, thereby affecting the overall performance, or stress concentration will easily occur due to excessive large-sized particles. Therefore, it is necessary to strictly control the mass ratio and average particle size of the first precious metal powder, the second precious metal powder, and the third precious metal powder.

[0049] In one embodiment, the photosensitive organic carrier comprises the following components in percentage by mass: 30-50% photosensitive resin, 2-8% photoinitiator, 0.2-1% dispersant, 0.2-0.8% leveling agent, 0.2-0.6% defoamer, 0.1-0.5% thixotropic agent, 4-20% diluent, and 30-50% solvent;

[0050] The molecular structure of the photosensitive resin contains a photosensitive group and an alkali-soluble group, and the acid value of the photosensitive resin is 25-200 mgKOH / g.

[0051] By selecting a photosensitive resin containing a photosensitive group and an alkali-soluble group in its molecular structure and having an acid value of 25-200 mgKOH / g, the affinity with the glass powder, precious metal powder and inorganic additives can be effectively improved, the glass powder, precious metal powder and inorganic additives of the present invention can be well wetted, the dispersibility of the system is improved, and the chemical stability, electrical conductivity and adhesion of the slurry are further improved.

[0052] In one embodiment, the photosensitive resin includes at least one of an alkali-soluble acrylic resin, an alkali-soluble epoxy acrylic resin, and an alkali-soluble polyurethane-modified acrylic resin.

[0053] In one embodiment, the photosensitive resin includes an alkali-soluble acrylic resin and an alkali-soluble epoxy acrylic resin, and the mass ratio of the alkali-soluble acrylic resin to the alkali-soluble epoxy acrylic resin is 1:(0.5-2). In particular, the alkali-soluble epoxy acrylic resin and the alkali-soluble acrylic resin with an acid value of 25-200 mgKOH / g are selected as the photosensitive resin, which can more effectively improve the chemical stability, electrical conductivity and adhesion.

[0054] Exemplarily, the alkali-soluble epoxy acrylic resin is purchased from Jining Tangyi Chemical Co., Ltd., product model WDS-1161, acid value 85-95 mgKOH / g.

[0055] Exemplarily, the alkali-soluble acrylic resin is purchased from Guangzhou Haoyi New Material Technology Co., Ltd., and the product models are Neocryl BT-24, Neocryl XK-39, Neocryl BT-21, and Neocryl BT-107-s.

[0056] The acid value of Neocryl BT-24 is 73 mgKOH / g, the acid value of Neocryl XK-39 is 129 mgKOH / g, the acid value of Neocryl BT-21 is 90 mgKOH / g, and the acid value of Neocryl BT-107-s is 150 mgKOH / g.

[0057] In one embodiment, the photoinitiator includes at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, thiopropoxythioxanthone, and diphenylacetone; and / or

[0058] The dispersant comprises at least one of a polyester dispersant and a polyether dispersant; and / or

[0059] The leveling agent comprises at least one of acrylated polysiloxane, polyether-modified polysiloxane, polysiloxane-polyether copolymer, and polysiloxane; and / or

[0060] The defoaming agent comprises at least one of tributyl phosphate, trimethylsiloxane, polyether, polyacrylate, and silicone resin; and / or

[0061] The thixotropic agent includes at least one of fumed silica and amide wax.

[0062] In one embodiment, the diluent includes at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and hydroxyethyl methacrylate; and / or

[0063] The solvent includes at least one of dimethyl oxalate, diethyl oxalate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, diethyl glutarate, dipropyl adipate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate.

[0064] In one embodiment, the glass powder includes the following components in mass percentage: 30~40% silicon dioxide (SiO2), 25~35% bismuth oxide (Bi2O3), 15~25% boron oxide (B2O3), 2~6% aluminum oxide (Al2O3), 2~5% zinc oxide (ZnO), 2~5% antimony oxide (Sb2O3), 1~3% zirconium oxide (ZrO2), and 0.5~2% tungsten trioxide (WO3).

[0065] In the specific formula system of the present invention, the glass powder of the present invention can provide suitable adhesion as a direct connection layer between the metal conductive layer and the substrate; secondly, the liquid glass phase at high temperature can also play a role in promoting the sintering of precious metal powder. At the same time, the glass powder can dissolve part of the precious metal (such as silver, etc.) after melting. In the cooling process after sintering, the precious metal dissolved in the glass liquid will precipitate due to the decrease in temperature and solubility. Since this type of precipitation is a microscopic atomic-level behavior, it crystallizes into nano-metal particles after precipitation. Due to the increase in the number of particles in the medium and the particle chains formed by the nano-particles, the number of conductive paths between the original metal particles can be increased, thereby enhancing the conductivity. In addition, the glass powder has good adhesion to the substrate, and the glass powder does not contain alkaline oxides, has good adhesion to the substrate, and will not react with the acidic groups in the thick-film photolithography slurry. It has good acid resistance and can stably exist in the thick-film photolithography slurry without affecting the development performance.

[0066] An embodiment of the present invention provides a method for preparing a negative thick film photolithography slurry, comprising the following steps:

[0067] The photosensitive resin, the photoinitiator, the dispersant, the leveling agent, the defoaming agent, the active diluent and the thixotropic agent are mixed uniformly to obtain a mixture, and the mixture is added into a solvent preheated to 50-60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0068] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry.

[0069] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims. Example 1

[0070] A negative thick film photolithography slurry comprises the following combination in mass percentage: 78% conductive metal phase, 20.5% photosensitive organic carrier, and 1.5% bonding phase.

[0071] The bonding phase includes glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additive is 1:0.5.

[0072] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1:1:0.5.

[0073] The glass powder includes the following components in parts by weight: 34% silicon dioxide, 28% bismuth oxide, 22% boron oxide, 5% aluminum oxide, 4% zinc oxide, 4% antimony oxide, 2% zirconium oxide, and 1% tungsten trioxide.

[0074] The method for preparing the glass powder comprises the following steps:

[0075] Silicon dioxide, bismuth oxide, boron oxide, aluminum oxide, zinc oxide, antimony oxide, zirconium oxide and tungsten trioxide are placed in an agate mortar, mixed evenly, and then placed in a corundum crucible, and then placed in a high-temperature furnace for smelting at a temperature of 1050°C and a smelting time of 60 minutes to obtain glass liquid. The glass liquid is cooled and formed in a stainless steel mold and then placed in a muffle furnace for annealing at a temperature of 500°C for 2 hours. Then, it is cooled to room temperature with the furnace and crushed into powder to obtain glass powder.

[0076] The conductive metal phase includes a first silver powder, a second silver powder, and a third silver powder; the mass ratio of the first silver powder, the second silver powder, and the third silver powder is 1:2:4; the average particle size of the first silver powder is 1 μm; the average particle size of the second silver powder is 5 μm; and the average particle size of the third silver powder is 15 μm.

[0077] The photosensitive organic carrier includes the following components in percentage by mass: 40% photosensitive resin, 5% diphenylacetophenone, 0.5% Hypermer KD-1 dispersant, 0.5% TEGO 270 leveling agent, 0.5% tributyl phosphate, 0.4% fumed silica, 12% 1,6-hexanediol diacrylate, and 41.1% diethyl oxalate.

[0078] The photosensitive resin includes WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin, and the mass ratio of WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin is 1:1.

[0079] The method for preparing the negative thick film photolithography slurry comprises the following steps:

[0080] WDS-1161 alkali-soluble epoxy acrylic resin, Neocryl BT-24 alkali-soluble acrylic resin, diphenylacetophenone, Hypermer KD-1 dispersant, TEGO 270 leveling agent, tributyl phosphate, fumed silica, and 1,6-hexanediol diacrylate are mixed uniformly to obtain a mixture, and the mixture is added into diethyl oxalate preheated to 60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0081] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry. Example 2

[0082] A negative thick film photolithography slurry comprises the following combination in mass percentage: 75% conductive metal phase, 23% photosensitive organic carrier, and 2% bonding phase.

[0083] The bonding phase includes glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additive is 1:0.8.

[0084] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1:1:0.5.

[0085] The glass powder includes the following components in parts by weight: 34% silicon dioxide, 28% bismuth oxide, 22% boron oxide, 5% aluminum oxide, 4% zinc oxide, 4% antimony oxide, 2% zirconium oxide, and 1% tungsten trioxide.

[0086] The method for preparing the glass powder comprises the following steps:

[0087] Silicon dioxide, bismuth oxide, boron oxide, aluminum oxide, zinc oxide, antimony oxide, zirconium oxide and tungsten trioxide are placed in an agate mortar, mixed evenly, and then placed in a corundum crucible, and then placed in a high-temperature furnace for smelting at a temperature of 1050°C and a smelting time of 60 minutes to obtain glass liquid. The glass liquid is cooled and formed in a stainless steel mold and then placed in a muffle furnace for annealing at a temperature of 500°C for 2 hours. Then, it is cooled to room temperature with the furnace and crushed into powder to obtain glass powder.

[0088] The conductive metal phase includes a first silver powder, a second silver powder, and a third silver powder; the mass ratio of the first silver powder, the second silver powder, and the third silver powder is 1:3:5; the average particle size of the first silver powder is 1 μm; the average particle size of the second silver powder is 5 μm; and the average particle size of the third silver powder is 15 μm.

[0089] The photosensitive organic carrier includes the following components in percentage by mass: 40% photosensitive resin, 5% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.5% Hypermer KD-1 dispersant, 0.5% TEGO 270 leveling agent, 0.5% tributyl phosphate, 0.4% fumed silica, 12% 1,6-hexanediol diacrylate, and 41.1% diethyl oxalate.

[0090] The photosensitive resin includes WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin, and the mass ratio of WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin is 1:0.5.

[0091] The method for preparing the negative thick film photolithography slurry comprises the following steps:

[0092] WDS-1161 alkali-soluble epoxy acrylic resin, Neocryl BT-24 alkali-soluble acrylic resin, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Hypermer KD-1 dispersant, TEGO 270 leveling agent, tributyl phosphate, fumed silica, and 1,6-hexanediol diacrylate are mixed uniformly to obtain a mixture, and the mixture is added into diethyl oxalate preheated to 60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0093] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry. Example 3

[0094] A negative thick film photolithography slurry comprises the following combination in mass percentage: 80% conductive metal phase, 19% photosensitive organic carrier, and 1% bonding phase.

[0095] The bonding phase includes glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additive is 1:0.4.

[0096] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1:1:0.5.

[0097] The glass powder includes the following components in parts by weight: 34% silicon dioxide, 28% bismuth oxide, 22% boron oxide, 5% aluminum oxide, 4% zinc oxide, 4% antimony oxide, 2% zirconium oxide, and 1% tungsten trioxide.

[0098] The method for preparing the glass powder comprises the following steps:

[0099] Silicon dioxide, bismuth oxide, boron oxide, aluminum oxide, zinc oxide, antimony oxide, zirconium oxide and tungsten trioxide are placed in an agate mortar, mixed evenly, and then placed in a corundum crucible, and then placed in a high-temperature furnace for smelting at a temperature of 1050°C and a smelting time of 60 minutes to obtain glass liquid. The glass liquid is cooled and formed in a stainless steel mold and then placed in a muffle furnace for annealing at a temperature of 500°C for 2 hours. Then, it is cooled to room temperature with the furnace and crushed into powder to obtain glass powder.

[0100] The conductive metal phase includes a first silver powder, a second silver powder, and a third silver powder; the mass ratio of the first silver powder, the second silver powder, and the third silver powder is 1:2:4; the average particle size of the first silver powder is 1 μm; the average particle size of the second silver powder is 5 μm; and the average particle size of the third silver powder is 15 μm.

[0101] The photosensitive organic carrier includes the following components in percentage by mass: 40% photosensitive resin, 5% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.5% Hypermer KD-1 dispersant, 0.5% TEGO 270 leveling agent, 0.5% tributyl phosphate, 0.4% fumed silica, 12% 1,6-hexanediol diacrylate, and 41.1% diethyl oxalate.

[0102] The photosensitive resin includes WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin, and the mass ratio of WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin is 1:1.

[0103] The method for preparing the negative thick film photolithography slurry comprises the following steps:

[0104] WDS-1161 alkali-soluble epoxy acrylic resin, Neocryl BT-24 alkali-soluble acrylic resin, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Hypermer KD-1 dispersant, TEGO 270 leveling agent, tributyl phosphate, fumed silica, and 1,6-hexanediol diacrylate are mixed uniformly to obtain a mixture, and the mixture is added into diethyl oxalate preheated to 60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0105] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry. Example 4

[0106] A negative thick film photolithography slurry comprises the following combination in mass percentage: 76% conductive metal phase, 22.8% photosensitive organic carrier, and 1.2% bonding phase.

[0107] The bonding phase includes glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additive is 1:0.6.

[0108] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1:0.5:1.

[0109] The glass powder includes the following components in parts by weight: 34% silicon dioxide, 28% bismuth oxide, 22% boron oxide, 5% aluminum oxide, 4% zinc oxide, 4% antimony oxide, 2% zirconium oxide, and 1% tungsten trioxide.

[0110] The method for preparing the glass powder comprises the following steps:

[0111] Silicon dioxide, bismuth oxide, boron oxide, aluminum oxide, zinc oxide, antimony oxide, zirconium oxide and tungsten trioxide are placed in an agate mortar, mixed evenly, and then placed in a corundum crucible, and then placed in a high-temperature furnace for smelting at a temperature of 1050°C and a smelting time of 60 minutes to obtain glass liquid. The glass liquid is cooled and formed in a stainless steel mold and then placed in a muffle furnace for annealing at a temperature of 500°C for 2 hours. Then, it is cooled to room temperature with the furnace and crushed into powder to obtain glass powder.

[0112] The conductive metal phase includes a first silver powder, a second silver powder, and a third silver powder; the mass ratio of the first silver powder, the second silver powder, and the third silver powder is 1:3:4; the average particle size of the first silver powder is 2 μm; the average particle size of the second silver powder is 5 μm; and the average particle size of the third silver powder is 20 μm.

[0113] The photosensitive organic carrier includes the following components in percentage by mass: 40% photosensitive resin, 5% thiopropoxythioxanthone, 0.5% Hypermer KD-1 dispersant, 0.5% TEGO 270 leveling agent, 0.5% tributyl phosphate, 0.4% fumed silica, 12% 1,6-hexanediol diacrylate, and 41.1% diethyl oxalate.

[0114] The photosensitive resin includes WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin, and the mass ratio of WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin is 1:0.8.

[0115] The method for preparing the negative thick film photolithography slurry comprises the following steps:

[0116] WDS-1161 alkali-soluble epoxy acrylic resin, Neocryl BT-24 alkali-soluble acrylic resin, thiopropoxythioxanthone, Hypermer KD-1 dispersant, TEGO 270 leveling agent, tributyl phosphate, fumed silica, and 1,6-hexanediol diacrylate are mixed uniformly to obtain a mixture, and the mixture is added into diethyl oxalate preheated to 60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0117] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry. Example 5

[0118] A negative thick film photolithography slurry comprises the following combination in mass percentage: 75% conductive metal phase, 24% photosensitive organic carrier, and 1% bonding phase.

[0119] The bonding phase includes glass powder and inorganic additives; the mass ratio of the glass powder to the inorganic additive is 1:0.7.

[0120] The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1:2:1.

[0121] The glass powder includes the following components in parts by weight: 34% silicon dioxide, 28% bismuth oxide, 22% boron oxide, 5% aluminum oxide, 4% zinc oxide, 4% antimony oxide, 2% zirconium oxide, and 1% tungsten trioxide.

[0122] The method for preparing the glass powder comprises the following steps:

[0123] Silicon dioxide, bismuth oxide, boron oxide, aluminum oxide, zinc oxide, antimony oxide, zirconium oxide and tungsten trioxide are placed in an agate mortar, mixed evenly, and then placed in a corundum crucible, and then placed in a high-temperature furnace for smelting at a temperature of 1050°C and a smelting time of 60 minutes to obtain glass liquid. The glass liquid is cooled and formed in a stainless steel mold and then placed in a muffle furnace for annealing at a temperature of 500°C for 2 hours. Then, it is cooled to room temperature with the furnace and crushed into powder to obtain glass powder.

[0124] The conductive metal phase includes a first silver powder, a second silver powder, and a third silver powder; the mass ratio of the first silver powder, the second silver powder, and the third silver powder is 1:2:4; the average particle size of the first silver powder is 0.5 μm; the average particle size of the second silver powder is 4 μm; and the average particle size of the third silver powder is 16 μm.

[0125] The photosensitive organic carrier includes the following components in percentage by mass: 40% photosensitive resin, 5% 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.5% Hypermer KD-1 dispersant, 0.5% TEGO 270 leveling agent, 0.5% tributyl phosphate, 0.4% fumed silica, 12% 1,6-hexanediol diacrylate, and 41.1% diethyl oxalate.

[0126] The photosensitive resin includes WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin, and the mass ratio of WDS-1161 alkali-soluble epoxy acrylic resin and Neocryl BT-24 alkali-soluble acrylic resin is 1:1.

[0127] The method for preparing the negative thick film photolithography slurry comprises the following steps:

[0128] WDS-1161 alkali-soluble epoxy acrylic resin, Neocryl BT-24 alkali-soluble acrylic resin, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Hypermer KD-1 dispersant, TEGO 270 leveling agent, tributyl phosphate, fumed silica, and 1,6-hexanediol diacrylate are mixed uniformly to obtain a mixture, and the mixture is added into diethyl oxalate preheated to 60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier;

[0129] The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry. Comparative Example 1

[0130] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain an inorganic additive, and the other aspects are the same.

[0131] A negative thick film photolithography slurry comprises the following combination in mass percentage: 78% conductive metal phase, 20.5% photosensitive organic carrier, and 1.5% bonding phase. Comparative Example 2

[0132] The difference between Comparative Example 2 and Example 1 is that the conductive metal phase of Comparative Example 2 is a single second silver powder, and the other aspects are the same.

[0133] The conductive metal phase is a first silver powder, and the average particle size of the first silver powder is 1 μm. Comparative Example 3

[0134] The difference between Comparative Example 3 and Example 1 is that the conductive metal phase of Comparative Example 3 is a single first silver powder, and the rest are the same.

[0135] The conductive metal phase is a second silver powder, and the average particle size of the second silver powder is 5 μm. Comparative Example 4

[0136] The difference between Comparative Example 4 and Example 1 is that the conductive metal phase of Comparative Example 4 is a single third silver powder, and the rest are the same.

[0137] The conductive metal phase is a third silver powder; the average particle size of the third silver powder is 15 μm. Comparative Example 5

[0138] The difference between Comparative Example 5 and Example 1 is that the mass ratio of the first silver powder, the second silver powder and the third silver powder is not within the scope of the present invention, and the others are the same.

[0139] The mass ratio of the first silver powder, the second silver powder and the third silver powder is 4:1:1. Comparative Example 6

[0140] The difference between Comparative Example 6 and Example 1 is that the mass ratio of the first silver powder, the second silver powder and the third silver powder is not within the scope of the present invention, and the others are the same.

[0141] The mass ratio of the first silver powder, the second silver powder and the third silver powder is 1:0.5:8. Comparative Example 7

[0142] The difference between Comparative Example 7 and Example 1 is that the photosensitive resin in Comparative Example 7 is different from that in Example 1, and the other aspects are the same.

[0143] The photosensitive resin is DH-JZ004 special modified polyurethane acrylic resin (Dinghao Photochemical Technology Co., Ltd.).

[0144] Test Case

[0145] 1. Adhesion (GB / T 17473.4-2008 Test method for adhesion of precious metal pastes for microelectronics technology, PET / glass substrate), the test results are shown in Table 1.

[0146] 2. The slurry was applied to a 96% alumina substrate printed by screen printing, dried, and sintered to obtain a substrate. The substrate was placed in a 20% hydrochloric acid aqueous solution and kept for 96 hours to see if the substrate had any peeling, cracks, or bubbles. The test results are shown in Table 1.

[0147] 3. Resistivity (the resistance value R at both ends of the test line is measured by a milliohm meter, the test line pattern length is L = 4.5cm, the line width is d = 20um, and the thickness h is measured by a screw micrometer. The resistivity ρ is calculated by the formula ρ = R × d × h / L).

[0148] Table 1

[0149] Adhesion / N 20% hydrochloric acid soak for 96h Resistivity / Ω.cm Example 1 48.9 No change <![CDATA[1.1×10 -6 ]]> Example 2 46.5 No change <![CDATA[1.5×10 -6 ]]> Example 3 45.3 No change <![CDATA[2.1×10 -6 ]]> Example 4 46.2 No change <![CDATA[1.7×10 -6 ]]> Example 5 45.7 No change <![CDATA[1.8×10 -6 ]]> Comparative Example 1 39.7 Bubbles appear <![CDATA[4.9×10 -6 ]]> Comparative Example 2 30.9 Cracks appear <![CDATA[3.9×10 -5 ]]> Comparative Example 3 31.4 Cracks appear <![CDATA[3.6×10 -5 ]]> Comparative Example 4 30.4 Cracks appear <![CDATA[4.3×10 -5 ]]> Comparative Example 5 32.7 Bubbles appear <![CDATA[1.9×10 -5 ]]> Comparative Example 6 31.6 Bubbles appear <![CDATA[2.3×10 -5 ]]> Comparative Example 7 37.5 Bubbles appear <![CDATA[9.8×10 -6 ]]>

[0150] It can be seen from Table 1 that the slurry of the present invention has excellent electrical conductivity, acid resistance and adhesion.

[0151] Among them, Example 1 is the best implementation mode of the present invention and has the best performance.

[0152] By comparing Example 1 with Comparative Example 1, it can be seen that the addition of inorganic additives can improve the conductivity, acid resistance and adhesion.

[0153] By comparing Example 1 with Comparative Examples 2 to 6, it can be seen that the present invention effectively improves the conductivity, acid resistance and adhesion by using the first precious metal powder, the second precious metal powder and the third precious metal powder of different particle sizes and controlling their mass ratio. If only a single first precious metal powder, the second precious metal powder or the third precious metal powder is used, and the mass ratio is not within the scope of the present invention, the performance will be reduced.

[0154] By comparing Example 1 with Comparative Example 7, it can be seen that the use of the photosensitive resin of the present invention further improves the conductivity, acid resistance and adhesion.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A negative thick film photolithography slurry, characterized in that: It includes the following mass percentage combination: 75-80% conductive metal phase, 15-25% photosensitive organic carrier, and 0.5-2% bonding phase; The bonding phase includes glass powder and inorganic additives; The mass ratio of the glass powder to the inorganic additive is 1:(0.1-0.8); The inorganic additives include bismuth oxide, zirconium oxide, and tungsten trioxide, and the mass ratio of the bismuth oxide, zirconium oxide, and tungsten trioxide is 1: (0.5-2): (0.2-1).

2. The negative thick film photolithography slurry according to claim 1, characterized in that: The composition comprises the following mass percentages: 75-80% of a conductive metal phase, 18-25% of a photosensitive organic carrier, and 0.8-2% of a bonding phase.

3. The negative thick film photolithography slurry according to claim 1, characterized in that: The conductive metal phase includes a first precious metal powder, a second precious metal powder, and a third precious metal powder; the mass ratio of the first precious metal powder, the second precious metal powder, and the third precious metal powder is 1: (1-4): (2-6); The average particle size of the first precious metal powder is 0.5-2 μm; the average particle size of the second precious metal powder is 4-8 μm; the average particle size of the third precious metal powder is 10-20 μm, The first precious metal powder, the second precious metal powder, and the third precious metal powder include one of silver powder, gold powder, silver-palladium powder, silver-coated copper powder, and platinum powder; The first precious metal powder, the second precious metal powder and the third precious metal powder are the same precious metal powder.

4. The negative thick film photolithography slurry according to claim 3, characterized in that: The mass ratio of the first precious metal powder, the second precious metal powder and the third precious metal powder is 1:(1-3):(2-5).

5. The negative thick film photolithography slurry according to claim 1, characterized in that: The photosensitive organic carrier comprises the following components in percentage by mass: 30-50% photosensitive resin, 2-8% photoinitiator, 0.2-1% dispersant, 0.2-0.8% leveling agent, 0.2-0.6% defoamer, 0.1-0.5% thixotropic agent, 4-20% diluent, and 30-50% solvent; The molecular structure of the photosensitive resin contains a photosensitive group and an alkali-soluble group, and the acid value of the photosensitive resin is 25-200 mgKOH / g.

6. The negative thick film photolithography slurry according to claim 5, characterized in that: The photosensitive resin includes at least one of an alkali-soluble acrylic resin, an alkali-soluble epoxy acrylic resin, and an alkali-soluble polyurethane-modified acrylic resin.

7. The negative thick film photolithography slurry according to claim 5, characterized in that: The photoinitiator comprises at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, thiopropoxythioxanthone and diphenylacetone; and / or The dispersant comprises at least one of a polyester dispersant and a polyether dispersant; and / or The leveling agent comprises at least one of acrylated polysiloxane, polyether-modified polysiloxane, polysiloxane-polyether copolymer, and polysiloxane; and / or The defoaming agent comprises at least one of tributyl phosphate, trimethylsiloxane, polyether, polyacrylate, and silicone resin; and / or The thixotropic agent includes at least one of fumed silica and amide wax.

8. The negative thick film photolithography slurry according to claim 5, characterized in that: The diluent includes at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and hydroxyethyl methacrylate; and / or The solvent includes at least one of dimethyl oxalate, diethyl oxalate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dipropyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, diethyl glutarate, dipropyl adipate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate.

9. The method for preparing a negative thick film photolithography slurry according to any one of claims 1 to 8, characterized in that: The following steps are involved: The photosensitive resin, the photoinitiator, the dispersant, the leveling agent, the defoaming agent, the active diluent and the thixotropic agent are mixed uniformly to obtain a mixture, and the mixture is added into a solvent preheated to 50-60° C., mixed uniformly, and filtered to obtain a photosensitive organic carrier; The photosensitive organic carrier, glass powder, inorganic additives and conductive metal are mixed evenly, ground and filtered to obtain negative thick film photolithography slurry.