Circuit manufacturing process and circuit board

Abstract

The invention discloses a manufacturing process of a circuit and a circuit board, and belongs to the technical field of microelectronics, and the manufacturing process of the circuit comprises the following steps: printing or coating photosensitive silver paste on a substrate to form a conductive circuit; and printing or coating photosensitive resistance paste on the substrate to form a resistor body. The conductive circuit is prepared by adopting the photosensitive silver paste, and the formed circuit is high in pattern precision and good in edge smoothness, so that the resistance consistency of the resistor body formed on the conductive circuit can be improved; in addition, the resistor body is prepared from the photosensitive resistor paste, the resistance stability of the resistor body can be controlled to be 1%-3%, and therefore the design requirements of most thick film circuits can be met without resistance adjustment. Therefore, the circuit manufacturing process provided by the invention can solve the problems of poor pattern precision and poor resistance value precision of the existing thick film hybrid integrated circuit.

Description

Technical Field

[0001] The present invention relates to the field of microelectronic technology, and in particular to a circuit manufacturing process and a circuit board. Background Art

[0002] At present, thick-film hybrid integrated circuits are formed by printing thick-film silver paste and thick-film resistor paste and then sintering. However, this method can only produce circuit patterns with a line width of 150μm and a line spacing of more than 200μm, and the accuracy of the circuit patterns is poor. On the other hand, the resistance consistency of the thick-film resistors formed by this method is poor, and the resistance stability is between 10% and 30%, which cannot meet the requirement of resistance stability between 0.3% and 5% in thick-film circuits. Summary of the invention

[0003] The main purpose of the present invention is to provide a circuit manufacturing process and a circuit board, aiming to solve the problems of poor graphic accuracy and poor resistance value accuracy existing in existing thick film hybrid integrated circuits.

[0004] To achieve the above object, the circuit manufacturing process provided by the present invention comprises the following steps:

[0005] Printing or coating photosensitive silver paste on the substrate to form a conductive circuit;

[0006] Print or coat photosensitive resistor paste on the substrate to form a resistor body.

[0007] In one embodiment, the step of “printing or coating a photosensitive silver paste on a substrate to form a conductive circuit” includes:

[0008] Print or coat the photosensitive silver paste on the substrate, dry the photosensitive silver paste, then perform mask exposure, development and sintering to obtain a conductive circuit.

[0009] In one embodiment, the step of “printing or coating a photosensitive resistor paste on a substrate to form a resistor body” includes:

[0010] Print or coat a photosensitive resistor paste on a substrate, dry the photosensitive resistor paste, perform mask exposure, development, and sintering to obtain a resistor body.

[0011] In one embodiment, the drying process is carried out at a temperature of 80°C to 120°C and a time of 5 min to 15 min; and / or,

[0012] The energy of the exposure treatment is 100mJ-1000mJ; and / or,

[0013] The developer for the development process is a sodium carbonate solution with a mass concentration of 0.1% to 0.5%; and / or,

[0014] The sintering temperature is 750°C-1000°C and the sintering time is 5min-15min.

[0015] In one embodiment, the thickness of the photosensitive silver paste is 6 μm-10 μm.

[0016] In one embodiment, the thickness of the photoresistor paste is 6 μm-10 μm.

[0017] In one embodiment, the photosensitive silver paste includes the following components in parts by weight:

[0018] 80-90 parts of first silver powder, 10-20 parts of first organic vehicle, 0.2-2.0 parts of first glass powder;

[0019] The first organic carrier includes a first resin, a photocurable prepolymer, a first photocurable monomer, a first photoinitiator, a coupling agent, a first auxiliary agent and a first solvent.

[0020] In one embodiment, the photoresistor paste includes the following components in parts by weight:

[0021] 50-70 parts of ruthenium oxide powder or modified ruthenium oxide powder, 25-35 parts of a second organic carrier, 1-5 parts of a second glass powder, 1-5 parts of a palladium powder, and 1-5 parts of a second silver powder;

[0022] The second organic carrier includes a second resin, a second photocurable monomer, a second photoinitiator, a second auxiliary agent and a second solvent.

[0023] In one embodiment, the second glass powder includes the following components in parts by weight:

[0024] 42-46 parts of silicon dioxide, 18-22 parts of boron oxide, 10-15 parts of bismuth oxide, 8-12 parts of copper oxide, 5-8 parts of zirconium oxide, 3-4 parts of lithium oxide, 1.5-2.5 parts of yttrium oxide, 0.8-1.5 parts of strontium oxide, and 0.2-0.6 parts of lanthanum oxide.

[0025] The present invention also provides a circuit board, which is manufactured by the above manufacturing process.

[0026] The present invention uses photosensitive silver paste to prepare the conductive circuit, and the line width / line spacing of the formed circuit pattern can reach 15μm / 15μm, and the edge flatness of the circuit pattern is good, and there is no problem of uneven edges, so that the resistance consistency of the resistor formed on the conductive circuit can be improved; in addition, the resistor of the present invention is prepared by photosensitive resistor paste, and the length and width of the resistor can be controlled within ±5μm, and the thickness consistency can be controlled within 1μm, so that the resistance stability of the resistor can be controlled within 1%-3%, so that the design requirements of most thick film circuits can be met without resistance adjustment. Therefore, the circuit manufacturing process of the present invention can solve the problems of poor graphic accuracy and poor resistance value accuracy in existing thick film hybrid integrated circuits. DETAILED DESCRIPTION

[0027] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. "At least one" appearing in the embodiments of the present invention refers to one or more, and "more than one" refers to two or more.

[0028] "Scope" disclosed in the present invention is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present invention, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0029] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] At present, thick film hybrid integrated circuits are formed by printing thick film silver paste and thick film resistor paste and then sintering them. However, this method has the following problems: on the one hand, the line edges of the formed silver circuit pattern are uneven, that is, the circuit pattern has poor flatness, and the control accuracy of the circuit pattern size is low, usually only a circuit pattern with a line width of 150μm and a line spacing of more than 200μm can be formed; on the other hand, due to the unevenness of the silver line edges, the resistance consistency of the resistor body formed after sintering the resistor paste overlapped on the silver conductive line is poor. Another factor leading to the poor resistance consistency of the resistor body is that the printed edge of the resistor paste itself is poorly neat, and the printed resistor paste has a coffee ring effect caused by surface tension, so that the thickness difference between the edge and the middle position of the resistor paste reaches 2-5μm. Therefore, the resistance stability of traditional thick film resistors is usually between 10% and 30%, which cannot meet the requirement of resistance stability of 0.3%-5% in thick film circuits.

[0031] The conventional solution is to add a resistance adjustment process, the purpose of which is to correct the resistance value through laser resistance adjustment. The specific principle is to use the four-probe measurement method to measure the initial resistance value, and then use the laser to groove the sintered resistor body by setting the laser path and laser power, thereby changing the resistance value. This not only increases the manufacturing process of thick-film hybrid integrated circuits, but also leads to an increase in the cost of thick-film hybrid integrated circuits. In addition, directly adjusting the resistance of the resistor body formed by the conventional manufacturing process also has the problem of low resistance adjustment efficiency.

[0032] To this end, an embodiment of the present invention provides a circuit manufacturing process, comprising the following steps:

[0033] Printing or coating photosensitive silver paste on the substrate to form a conductive circuit;

[0034] Print or coat photosensitive resistor paste on the substrate to form a resistor body.

[0035] Photosensitive silver paste, also known as photosensitive silver paste, is a special silver paste that can undergo a chemical reaction under light irradiation. It can be quickly cured under light of a specific wavelength, thereby being able to precisely control the conductive circuit pattern.

[0036] Photosensitive resistor paste also refers to photosensitive resistor paste, which can also be cured under light of a specific wavelength, so that the effective length and thickness of the resistor can be accurately controlled. The volume of the conductive part of the resistor is one of the factors affecting the resistance of the resistor. The volume of the conductive part is related to the effective length, width and thickness of the resistor. Therefore, the volume of the conductive part of the resistor can be controlled by the photosensitive process, thereby controlling the resistance accuracy of the resistor.

[0037] The present invention adopts photosensitive silver paste to prepare the conductive circuit, and the precision of the formed circuit pattern is ±5μm, the line width / line spacing can reach 15μm / 15μm, and the precision of the circuit pattern is improved; the edge flatness of the circuit pattern is good, the lines are straight, and there is no problem of uneven edges, so the resistance consistency of the resistor formed on the conductive circuit can be improved. In addition, the resistor of the present invention is prepared by photosensitive resistor paste, and the length and width of the resistor can be controlled within ±5μm, and the thickness consistency is controlled within 1μm, so that the resistance stability of the resistor can be controlled within 1%-3%, and the design requirements of most thick film circuits can be met without adjusting the resistance. Therefore, the circuit manufacturing process of the present invention can solve the problems of poor graphic accuracy and poor resistance value accuracy in existing thick film hybrid integrated circuits.

[0038] In addition, the resistor prepared by the process of the present invention still has the properties of laser resistance trimming or high-voltage pulse resistance trimming. In order to meet some extremely special design requirements (resistance stability reaches 0.3-1%), laser resistance trimming or high-voltage pulse resistance trimming can be added on the basis of this process method, which can significantly improve the resistance trimming efficiency and accuracy, thereby meeting the needs of rapid large-scale production.

[0039] It should be noted that in actual applications, according to the requirements of circuit design, the conductive circuit and the resistor are not prepared in a completely sequential order. In addition, other process steps can be inserted into the manufacturing process of the conductive circuit and the resistor according to the design and process requirements.

[0040] In an embodiment of the present invention, the step of "printing or coating photosensitive silver paste on a substrate to form a conductive circuit" includes: printing or coating photosensitive silver paste on the substrate, drying the photosensitive silver paste, then performing mask exposure, development, and sintering to obtain a conductive circuit.

[0041] In an embodiment of the present invention, the step of "printing or coating a photosensitive resistor paste on a substrate to form a resistor body" includes: printing or coating a photosensitive resistor paste on a substrate, drying the photosensitive resistor paste, and then performing mask exposure, development, and sintering to obtain a resistor body.

[0042] Printing can be done by screen printing or pad printing, and coating can be done by roller coating or spin coating.

[0043] The drying process is to bake the substrate in air to remove part of the solvent and moisture in the slurry, so that the slurry can be solidified and better adhered to the substrate.

[0044] Mask exposure also refers to photolithography exposure, which is to transfer the pattern on the mask to the substrate through the mask and light source. Specifically, the mask is placed above the substrate and fixed, and then the mask and substrate are irradiated by a light source (such as ultraviolet light, deep ultraviolet light, extreme ultraviolet light or electron beam), and the photoresist (photosensitive silver paste or photosensitive resistor paste) blocked by the mask becomes soluble.

[0045] Development refers to the process of retaining the photoresist in the exposed area and dissolving the photoresist in the unexposed area through the action of the developer, thereby forming a desired pattern, that is, the photosensitive silver paste and photosensitive resistor paste used in the embodiment of the present invention are negative photoresists. Of course, in other embodiments, positive photoresists can also be used.

[0046] The main function of sintering treatment is to improve the adhesion between photoresist and substrate to ensure the stability and quality of the pattern. In addition, sintering treatment helps to remove possible residual solvents or other volatile components in the photoresist and reduce internal stress to improve the uniformity and stability of the photoresist.

[0047] In an embodiment of the present invention, the drying temperature is 80° C.-120° C. and the drying time is 5 min-15 min; and / or,

[0048] The energy of the exposure treatment is 100mJ-1000mJ; and / or,

[0049] The developer for the development process is a sodium carbonate solution with a mass concentration of 0.1% to 0.5%; and / or,

[0050] The sintering temperature is 750°C-1000°C and the sintering time is 5min-15min.

[0051] In the embodiment of the present invention, the thickness of the photosensitive silver paste is 6 μm-10 μm. This thickness range can meet the requirements of the circuit conductivity and will not cause development defects due to the paste being too thick.

[0052] In an embodiment of the present invention, the thickness of the photoresistor slurry is 6 μm-10 μm. This thickness range can provide good leveling and thickness consistency, and will not cause development defects due to the slurry being too thick.

[0053] In an embodiment of the present invention, the photosensitive silver paste includes the following components in parts by weight:

[0054] 80-90 parts of first silver powder, 10-20 parts of first organic vehicle, 0.2-2.0 parts of first glass powder;

[0055] The first organic carrier includes a first resin, a photocurable prepolymer, a first photocurable monomer, a first photoinitiator, a coupling agent, a first auxiliary agent and a first solvent.

[0056] The first silver powder can be spherical nano silver powder and / or submicron silver powder, and the particle size of the first silver powder can be selected between 50nm-1μm. Mixing nano silver powder and submicron silver powder can improve the dispersion performance of the first silver powder.

[0057] The first glass powder may include at least one of silicon dioxide, bismuth oxide, boron oxide, zinc oxide, sodium oxide, zirconium oxide, and titanium dioxide. Exemplarily, the first glass powder may include the following components in parts by weight: 45-55 parts of silicon dioxide, 18-25 parts of boron oxide, 12-20 parts of bismuth oxide, 4-6 parts of sodium oxide, 0.8-1.5 parts of zirconium oxide, and 0.1-0.4 parts of titanium dioxide.

[0058] The first resin is a resin containing photosensitive groups and alkali-soluble groups in its structure. The photosensitive resin containing photosensitive groups and alkali-soluble groups can effectively improve the affinity with the glass powder, can well wet the glass powder, improve the dispersibility of the system, and further improve the chemical stability and insulation performance of the photosensitive silver paste. Further, the first resin can be a water-based alkali-soluble acrylic resin. For example, the product model of the water-based alkali-soluble acrylic resin is Neocryl BT-24, Neocryl BT-21.

[0059] The photocurable prepolymer includes polyester-modified acrylate, and illustratively, the photocurable prepolymer includes polyurethane acrylate.

[0060] The first photocurable monomer includes at least one of methyl methacrylate, n-butyl methacrylate, lauryl methacrylate, trimethylolpropane triglycidyl ester, and pentaerythritol tetraglycidyl ester.

[0061] The first photoinitiator includes at least one of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator TPO), 1-hydroxycyclohexylphenyl ketone (photoinitiator 184), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (photoinitiator 907), 2-isopropylthioxanthone (photoinitiator ITX), η6-isopropylphenylferrocene hexafluorophosphate (photoinitiator 261), and 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(0-benzoyl oxime).

[0062] The coupling agent includes at least one of vinyl trimethoxy silane, vinyl tri (β-methoxyethoxy) silane, vinyl triethoxy silane, 3-mercaptopropyl triethoxy silane and 3-mercaptopropyl trimethoxy silane.

[0063] The first auxiliary agent includes at least one of a first leveling agent, a first defoamer, a first dispersant, and a film-forming aid. Among them, the first leveling agent includes at least one of an acrylate leveling agent and an organosilicon leveling agent. For example, the acrylate leveling agent can be acrylic acid, methyl methacrylate, isooctyl acrylate, butyl acrylate, butyl methacrylate, hydroxyethyl acrylate, or hydroxypropyl acrylate; the organosilicon leveling agent can be polysiloxane, silane coupling agent, silicone oil, or modified silicone oil. The first defoamer is an organosilicon defoamer. For example, the organosilicon defoamer can be polysiloxane, silicone oil, modified silicone oil, or silane coupling agent. The first dispersant includes at least one of a phosphate ester polymer, a fatty acid ethylene oxide adduct, and a polyethylene glycol-type polyol. For example, the phosphate ester polymer can be a polyphosphate ester, a polyphosphate ester amide, a polyphosphate ester ether, or a polyphosphate ester acrylate; the fatty acid ethylene oxide adduct can be a polyamide wax, a polyamic acid, a polyamic acid ester, or a polyamide wax ester. The film-forming aid includes at least one of alcohol ester dodecahydrate, tributyl citrate and acetyl tributyl citrate.

[0064] The first solvent includes at least one of diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, diethylene glycol butyl ether, terpineol, ethylene glycol ethyl ether acetate, and ethylene glycol butyl ether acetate.

[0065] In an embodiment of the present invention, the photosensitive resistor paste includes the following components in parts by weight:

[0066] 50-70 parts of ruthenium oxide powder or modified ruthenium oxide powder, 25-35 parts of a second organic carrier, 1-5 parts of a second glass powder, 1-5 parts of a palladium powder, and 1-5 parts of a second silver powder;

[0067] The second organic carrier includes a second resin, a second photocurable monomer, a second photoinitiator, a second auxiliary agent and a second solvent.

[0068] The modified ruthenium oxide powder can be formed by coating or dispersing the ruthenium oxide powder with organic matter, or by modifying the ruthenium oxide powder with other types of metals or metal salts during the synthesis of ruthenium oxide, etc. The purpose is to improve the dispersibility of ruthenium oxide, sintering consistency, control the temperature coefficient of resistance, etc. The embodiment of the present invention does not impose any specific restrictions on the selection of modified ruthenium oxide powder.

[0069] The second glass powder helps the resistor paste to adhere to the substrate, helps to improve the sintering degree and consistency of the resistor paste, and helps to overlap and bond between the resistor paste and the silver paste.

[0070] The second resin is a resin containing photosensitive groups and alkali-soluble groups in its structure. The photosensitive resin containing photosensitive groups and alkali-soluble groups can effectively improve the affinity with the glass powder, can well wet the glass powder, improve the dispersibility of the system, and further improve the chemical stability and insulation performance of the photosensitive resistor slurry. Further, the second resin can be a water-based alkali-soluble acrylic resin. For example, the product model of the water-based alkali-soluble acrylic resin is Neocryl BT-24, Neocryl BT-21.

[0071] The second photocurable monomer includes trimethylolpropane trimethacrylate and / or dipentaerythritol hexaacrylate.

[0072] The second photoinitiator includes 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (photoinitiator 907), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819), 2-isopropylthioxanthone (photoinitiator ITX), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime) (photoinitiator O XE-2), bis(1-(2,4-difluorophenyl)-3-pyrrolyl)titanocene (photoinitiator 784), diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator TPO), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (photoinitiator TPO-L), 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (photoinitiator 2959).

[0073] The second auxiliary agent includes at least one of a second leveling agent, a second defoamer, and a second dispersant. The second leveling agent includes at least one of an acrylic leveling agent and an organosilicon leveling agent. The second defoamer is an organosilicon defoamer. The second dispersant includes at least one of a phosphate polymer, a fatty acid ethylene oxide adduct, and a polyethylene glycol polyol.

[0074] The second solvent includes at least one of diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, alcohol ester dodecahydrate, propylene glycol methyl ether, dipropylene glycol methyl ether, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, methyl methacrylate, lauryl methacrylate, and methacrylic acid.

[0075] In an embodiment of the present invention, the second glass powder includes the following components in parts by weight:

[0076] 42-46 parts of silicon dioxide, 18-22 parts of boron oxide, 10-15 parts of bismuth oxide, 8-12 parts of copper oxide, 5-8 parts of zirconium oxide, 3-4 parts of lithium oxide, 1.5-2.5 parts of yttrium oxide, 0.8-1.5 parts of strontium oxide, and 0.2-0.6 parts of lanthanum oxide.

[0077] In this embodiment, the mass ratio of the second glass powder to the ruthenium oxide powder / modified ruthenium oxide powder can be further set to 1:(15-40). The second glass powder in this ratio can provide sufficient substrate adhesion to the resistor paste and is beneficial to the consistency of resistor sintering. If the second glass powder content is higher, it will lead to problems such as increased resistance value, poor resistance uniformity, and large temperature coefficient of resistance.

[0078] The present invention also proposes a circuit board, which is manufactured by the above-mentioned manufacturing process. The manufacturing process specifically refers to the above-mentioned embodiments. Since the circuit board adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0079] The following describes the invention in conjunction with specific embodiments.

[0080] Example 1

[0081] A process for manufacturing a circuit comprises the following steps:

[0082] (1) printing a photosensitive silver paste on a ceramic substrate by screen printing, wherein the printing thickness of the photosensitive silver paste is 8 μm, and then baking and drying at 90° C. for 10 min to obtain a first film layer;

[0083] (2) using ultraviolet light on a photolithography machine to expose the first film layer to a mask, with an exposure energy of 500 mJ and an exposure time of 20 s; then using a sodium carbonate solution with a mass concentration of 0.2% for development for 2 min, retaining the silver paste in the exposed area; then sintering at 850° C. for 10 min to obtain a conductive circuit with a line width of 20 μm and a line spacing of 430 μm;

[0084] (3) printing a photosensitive resistor paste on the conductive circuit obtained in step (2) by screen printing, the printing thickness of the photosensitive resistor paste being 8 μm, and then baking and drying at 90° C. for 10 min to obtain a second film layer;

[0085] (4) Using ultraviolet light on a photolithography machine, the second film layer is exposed to mask with an exposure energy of 500 mJ and an exposure time of 40 s. Then, a developer is used for development for 2 min, retaining the resistor slurry in the exposed area. Then, the resistor body is obtained by sintering at 850° C. for 10 min.

[0086] The photosensitive silver paste includes the following components in parts by weight: 80 parts of first silver powder, 10 parts of first organic vehicle, and 1 part of first glass powder; wherein the first organic vehicle includes the following components in parts by weight:

[0087] 40 parts of Neocryl BT-24, 10 parts of polyurethane acrylate, 20 parts of trimethylolpropane triglycidyl ester, 5 parts of photoinitiator TPO, 1 part of vinyl trimethoxy silane, 0.5 parts of leveling agent BYK-333, 0.5 parts of defoamer BYK-012, 1 part of dispersant BYK-110, 0.5 parts of alcohol ester dodecyl and 50 parts of diethylene glycol ethyl ether acetate.

[0088] The photosensitive resistor paste includes the following components in parts by weight: 70 parts of modified ruthenium oxide powder, 25 parts of a second organic carrier, 3 parts of a second glass powder, 3 parts of a palladium powder, and 3 parts of a second silver powder; wherein the second organic carrier includes the following components in parts by weight:

[0089] 50 parts of Neocryl BT-24, 15 parts of trimethylolpropane trimethacrylate, 4 parts of photoinitiator 907, 1.5 parts of leveling agent BYK-333, 1.5 parts of defoamer BYK-012, 2 parts of dispersant BYK-110, and 30 parts of diethylene glycol butyl ether acetate.

[0090] Example 2

[0091] Different from the first embodiment, the line width of the conductive circuit in this embodiment is 20 μm, and the line spacing is 30 μm. The remaining steps are the same as those in the first embodiment.

[0092] Example 3

[0093] Different from the first embodiment, the line width of the conductive circuit in this embodiment is 100 μm, and the line spacing is 350 μm. The remaining steps are the same as those in the first embodiment.

[0094] Example 4

[0095] Different from Example 1, the printing thickness of the photosensitive silver paste in this embodiment is 6 μm, the printing thickness of the photosensitive resistor paste is 6 μm, the line width of the conductive circuit is 100 μm, the line spacing is 350 μm, and the remaining steps are the same as Example 1.

[0096] Example 5

[0097] Different from Example 1, the printing thickness of the photosensitive silver paste in this embodiment is 10 μm, the printing thickness of the photosensitive resistor paste is 10 μm, the line width of the conductive circuit is 100 μm, the line spacing is 350 μm, and the remaining steps are the same as Example 1.

[0098] Comparative Example 1

[0099] Different from the first embodiment, the present embodiment adopts conventional thick film silver paste to prepare the conductive circuit and adopts conventional thick film resistor paste to prepare the resistor body, which specifically includes the following steps:

[0100] (1) printing a thick film silver paste on a ceramic substrate by screen printing, and then baking and drying at 90° C. for 10 minutes to obtain a first film layer;

[0101] (2) sintering the substrate in step (1) at 850° C. for 10 min to obtain a conductive circuit, wherein the line width of the conductive circuit is 150 μm and the line spacing is 350 μm;

[0102] (3) printing a thick film resistor paste on the conductive circuit obtained in step (2) by screen printing, and then baking and drying at 90° C. for 10 minutes to obtain a second film layer;

[0103] (4) Sinter the substrate in step (3) at 850°C for 10 minutes to obtain a resistor.

[0104] The thick film silver paste in this comparative example includes the following components in parts by weight:

[0105] 80 parts of silver powder, 10 parts of cellulose resin, 0.5 parts of leveling agent BYK-333, 0.5 parts of defoaming agent BYK-012, 1 part of dispersant BYK-110, 40 parts of ethylene glycol ethyl ether.

[0106] The thick film resistor paste in this comparative example includes the following components in parts by weight:

[0107] 70 parts of ruthenium oxide powder, 25 parts of cellulose resin, 3 parts of palladium powder, 3 parts of silver powder, 1.5 parts of leveling agent BYK-333, 1.5 parts of defoaming agent BYK-012, 2 parts of dispersant BYK-110, and 40 parts of ethylene glycol ethyl ether.

[0108] Comparative Example 2

[0109] Different from Example 1, this embodiment uses conventional thick film silver paste to prepare the conductive pattern, and uses photosensitive resistor paste to prepare the resistor body, which specifically includes the following steps:

[0110] (1) printing a thick film silver paste on a ceramic substrate by screen printing, and then baking and drying at 90° C. for 10 minutes to obtain a first film layer;

[0111] (2) sintering the substrate in step (1) at 850° C. for 10 min to obtain a conductive circuit, wherein the line width of the conductive circuit is 150 μm and the line spacing is 350 μm;

[0112] (3) printing a photosensitive resistor paste on the conductive circuit obtained in step (2) by screen printing, the printing thickness of the photosensitive resistor paste being 8 μm, and then baking and drying at 90° C. for 10 min to obtain a second film layer;

[0113] (4) Using ultraviolet light on a photolithography machine, the second film layer is exposed to mask with an exposure energy of 500 mJ and an exposure time of 40 s. Then, a developer is used for development for 2 min, retaining the resistor slurry in the exposed area. Then, the resistor body is obtained by sintering at 850° C. for 10 min.

[0114] Comparative Example 3

[0115] Different from Example 1, this embodiment uses photosensitive silver paste to prepare the conductive pattern, and conventional thick film resistor paste to prepare the resistor body, which specifically includes the following steps:

[0116] (1) printing a photosensitive silver paste on a ceramic substrate by screen printing, wherein the printing thickness of the photosensitive silver paste is 8 μm, and then baking and drying at 90° C. for 10 min to obtain a first film layer;

[0117] (2) using ultraviolet light on a photolithography machine to expose the first film layer to a mask, with an exposure energy of 500 mJ and an exposure time of 20 s; then using a sodium carbonate solution with a mass concentration of 0.2% for development for 2 min, retaining the silver paste in the exposed area; then sintering at 850° C. for 10 min to obtain a conductive circuit with a line width of 20 μm and a line spacing of 430 μm;

[0118] (3) printing a thick film resistor paste on the conductive circuit obtained in step (2) by screen printing, and then baking and drying at 90° C. for 10 minutes to obtain a second film layer;

[0119] (4) Sinter the substrate in step (3) at 850°C for 10 minutes to obtain a resistor.

[0120] Performance Testing

[0121] The thickness of the conductive circuits, the size of the resistors, and the resistance values ​​of the resistors prepared in Examples 1-5 and Comparative Examples 1-5 were tested. The thickness test was performed using a step profiler and a 3D microscope, with a multi-point measurement method selected; the size test was performed using a metallographic microscope and a 3D microscope, with a multi-point measurement method selected; the resistance value was tested using a resistance tester, with a multi-point measurement method selected. The results are shown in Table 1.

[0122] Table 1 Test results in Examples 1-5 and Comparative Examples 1-5

[0123]

[0124]

[0125] It can be seen from the above table that the tolerance between the test resistance of the resistors formed in Examples 1-5 of the present invention and the target resistance value is relatively small, all lower than 3%, while the tolerance between the test resistance of the resistors in the comparative example and the target resistance is as low as 9% and as high as 25%, indicating that the method of forming a resistor body by using photosensitive silver paste to form a conductive pattern and using photosensitive resistor paste in the present invention can significantly improve the accuracy of the resistance value of the resistor body, and can meet the design requirements of most thick film circuits without adjusting the resistance.

[0126] Comparative Examples 1-3 show that when the printed thickness of the photosensitive silver paste and the photosensitive resistor paste remains unchanged, the tolerance between the test resistance of the resistor and the target resistance value will change by changing the line width and line spacing of the conductive circuit, but the tolerance values ​​are all less than 3%, indicating that the circuits with different line widths and line spacings manufactured using the manufacturing process of the embodiment of the present invention have higher precision. Comparative Examples 3-5 show that when the line width and line spacing of the conductive circuit remain unchanged, the tolerance between the test resistance of the resistor and the target resistance value will also change by changing the printed thickness of the photosensitive silver paste and the photosensitive resistor paste. However, the above changes are not linearly related.

[0127] It can also be seen from the above table that when using traditional thick film silver paste and thick film resistor paste for printing in the comparative example, the thickness data of the thick film silver paste and thick film resistor paste are all within the same range. This is because the thickness consistency of the thick film printing itself is poor, and the local thickness range is extremely different by 1-2μm.

[0128] The difference between the comparative example and the example in the line width and line spacing data of the conductive circuit is because the thick film silver paste will overflow when printing, resulting in a larger size than the designed value. The difference between the comparative example and the example in the resistor body size data is also due to the overflow of thick film printing, resulting in a larger size.

[0129] By comparing Example 1 with Comparative Example 2, it can be seen that when only the photosensitive silver paste is replaced with thick film silver paste, the tolerance between the test resistance of the resistor and the target resistance increases from 1.5% to 15%; by comparing Example 1 with Comparative Example 3, it can be seen that when only the photosensitive resistor paste is replaced with thick film resistor paste, the tolerance between the test resistance of the resistor and the target resistance increases from 1.5% to 9%. This is mainly because the printing edge consistency of traditional thick film silver paste and thick film resistor paste is poor, and there is also a difference between the thickness at the edge and the thickness at the middle, which causes fluctuations in the equivalent cross-sectional area and equivalent length of the resistor, resulting in poor consistency of the resistance value. From the above comparison, it can be further seen that the thick film silver paste has a great influence on the consistency of the resistance value, and the influence of the thick film resistor paste on the resistance value is second.

[0130] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the technical concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A process for manufacturing a circuit, characterized in that: The following steps are involved: Printing or coating photosensitive silver paste on the substrate to form a conductive circuit; Print or coat photosensitive resistor paste on the substrate to form a resistor body.

2. The process for manufacturing a circuit as claimed in claim 1, characterized in that: The step of "printing or coating a photosensitive silver paste on a substrate to form a conductive circuit" includes: Print or coat the photosensitive silver paste on the substrate, dry the photosensitive silver paste, then perform mask exposure, development and sintering to obtain a conductive circuit.

3. The process for manufacturing a circuit as claimed in claim 1, characterized in that: The step of "printing or coating a photosensitive resistor paste on a substrate to form a resistor body" includes: Print or coat a photosensitive resistor paste on a substrate, dry the photosensitive resistor paste, perform mask exposure, development, and sintering to obtain a resistor body.

4. The process for manufacturing a circuit as claimed in claim 2 or 3, characterized in that: The drying process is performed at a temperature of 80°C to 120°C and for a time of 5 min to 15 min; and / or, The energy of the exposure treatment is 100mJ-1000mJ; and / or, The developer for the development treatment is a sodium carbonate solution with a mass concentration of 0.1%-0.5%; and / or, The sintering treatment is carried out at a temperature of 750° C. to 1000° C. and for a time of 5 min to 15 min.

5. The process for manufacturing a circuit as claimed in claim 1 or 2, characterized in that: The thickness of the photosensitive silver paste is 6 μm-10 μm.

6. The process for manufacturing a circuit as claimed in claim 1 or 3, characterized in that: The thickness of the photosensitive resistor slurry is 6 μm-10 μm.

7. The process for manufacturing a circuit as claimed in claim 1 or 2, characterized in that: The photosensitive silver paste comprises the following components in parts by weight: 80-90 parts of first silver powder, 10-20 parts of first organic vehicle, 0.2-2.0 parts of first glass powder; The first organic carrier includes a first resin, a photocurable prepolymer, a first photocurable monomer, a first photoinitiator, a coupling agent, a first auxiliary agent and a first solvent.

8. The process for manufacturing a circuit as claimed in claim 1 or 3, characterized in that: The photosensitive resistor paste comprises the following components in parts by weight: 50-70 parts of ruthenium oxide powder or modified ruthenium oxide powder, 25-35 parts of a second organic carrier, 1-5 parts of a second glass powder, 1-5 parts of a palladium powder, and 1-5 parts of a second silver powder; The second organic vehicle includes a second resin, a second photocurable monomer, a second photoinitiator, a second auxiliary agent and a second solvent.

9. The process for manufacturing a circuit as claimed in claim 8, characterized in that: The second glass powder includes the following components in parts by weight: 42-46 parts of silicon dioxide, 18-22 parts of boron oxide, 10-15 parts of bismuth oxide, 8-12 parts of copper oxide, 5-8 parts of zirconium oxide, 3-4 parts of lithium oxide, 1.5-2.5 parts of yttrium oxide, 0.8-1.5 parts of strontium oxide, and 0.2-0.6 parts of lanthanum oxide.

10. A circuit board, characterized in that: The method is manufactured by the manufacturing process according to any one of claims 1 to 9.

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