TW200828344A - Composition of polymer thick film resistor and manufacturing method thereof - Google Patents

Abstract

A composition of polymer thick film resistor comprises an epoxy resin system, at least one conductive powder, a polymer disperser and a hardener. The epoxy resin comprises a multi-functional epoxy resin with a multi-function number equal to or greater than 4. The conductive powder has an average grain size between 10-100 nm. By blending and dispersing processes, the resistance tolerance of the polymer thick film resistor can be significantly diminished, and as a result the polymer thick film resistor is suitable to serve as an embedded resistor in a printed circuit board or an IC substrate.

Description

200828344 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD The present invention relates to a resistor composition and a method of fabricating the same, and more particularly to a polymer thick film resistor composition and a method of fabricating the same. [Prior Art] With the demand for high functionality of communication electronic products and the high frequency of signal transmission, the demand for passive components and active components has increased significantly. In order to improve the performance of passive components, reduce the number of passive components, reduce the surface area of the board, and take advantage of the miniaturization technology, independent passive components such as capacitors, resistors and inductors are gradually become embedded passive components, which are inserted into the circuit board. To increase device density and reduce substrate area. The high-speed high-frequency transmission of signal transmission and the shortening of transmission distance also have some problems to be improved, such as the rapid development of High Density Intercomiection (HDI), when the density between components is increased, between components and components. The parasitic effect is also obvious. Especially in high-frequency transmission applications, it is more likely to cause problems such as noise and signal delay, and electromagnetic interference (EMI). If you use buried capacitors, you can reduce or reduce them. The parasitic effect greatly enhances the performance of the product at high speed and high speed. It also reduces the number of Solder Joints, Through Holes, and Micrvias, and increases the yield of the product. The advantages of the buried resistor are that it can reduce the substrate area, reduce the cost, and effectively improve the function of the component. When a buried resistor is used, the resulting series inductance is much smaller than that of a freestanding resistor. In the case where the rise time (Rise time) is very short, 100210-116389 005936987-1 200828344, the induced impedance generated by using a freestanding resistor increases. With built-in resistors, this inductive impedance can be almost ignored due to the short transmission distance. However, when the transmission frequency exceeds 1 ΟΌΜΗζ, the amount of resistance required increases. In order to reduce assembly costs, improve performance, reduce the use area and improve reliability, it is necessary to replace the surface mount (SMT) resistor with a buried resistor. Typical applications include: open receivers for digital resistor products, LED current control, line termination, and more. Buried resistors can be divided into two categories on the product, one is a thin film resistor and the other is a thick film resistor. The former can use Electroplate, Sputter or Chemical Vapor Deposition (CVD). The latter method is based on the traditional screen printing method. Common thick film resistors can be divided into high temperature sintering type and low temperature baking type according to the choice of substrate and subsequent thermal reaction. High-temperature sintering type refers to a thick film sintered at 500~900 °C, suitable for integration in a ceramic substrate; and another thick film resistor suitable for PCB buried technology is a low-temperature baking type. After the printing process, baking with hot air at 120~200 °C or using UV irradiation, in addition to volatilizing the solvent, the thermosetting resin in the coating generates cross-linking hardening to form a desired pattern, so-called polymer thick film resistor (Polymer Thick Film Resistor), referred to as PTF resistor. PTF resistors are mainly based on polymer resins and filled with conductive materials. They are characterized by the use of general thick film printing, which prints the pattern straight on the dielectric layer or the etched copper line, and the baking temperature is consistent. The general PCB process is small in size, light in weight and inexpensive, and has a large sheet resistance range from 15 Ω to 1 M Ω. However, the disadvantage is that the variability (Tolerance) is large, about 10 to 50. % is not equal, in order to improve this shortcoming and expand its applicability of 100210-116389 005936987-1 -6- 200828344, increasing the range of resistance values and reducing the error variability (< 5%) is the focus. The development of embedded passive component technology has been for many years. In the patent, most of the exposers mostly use the patents on resistance process and low temperature co-fired multilayer ceramics (LTCC). The material formulation is only part of the resistance material formula. They are simply described as a mixture of a polymer resin (such as an epoxy resin) and a conductive powder (such as carbon black). It is not known that there are still quite a few important formulation techniques to be clarified, and it is not a conventional polymer resin (such as epoxy). The mixing of the resin and the conductive powder can be arbitrarily achieved.

With regard to current PTF material patents, RCA Corp. has developed PTF resistor formulations since 1984 (US Patent 4,479,890), but did not disclose the application of buried resistors. In addition, Advanced Products Inc. has been applying for a patent for a polymer thick film resistor material formulation since 1991 (U.S. Patent No. 5,049,313, US Pat. No. 5,200,264), which is incorporated herein by reference. Blocked polyisocyanate resin) The system is the main resin, mixed with the conductive powder in an appropriate ratio, and screen-printing method, can be cured at low temperature and in a short time, and its PTF has good material storage. Good flexibility, good solvent resistance and good adhesion. It has good stability under high temperature and short time. It is mainly for material reliability research, and it is not for resistance and dimensional stability. discuss. In the past, the solution to the problem of dimensional stability of thick film resistors was nothing more than a change in the method, and the other was to change the material formulation, which was proposed by Hui-min Huang, Cliia-Tin Chung et al. in 2000. The patent (US 100210-116389 005936987-1 -7- 200828344 6'〇30,553) belongs to the latter, which emphasizes the cyclic aliphatic structure as the main body and is a solvent-free system. After screen printing, UV exposure The external hardening of the resistor is fixed, and the internal structure is cross-linked and cured by heating, thereby obtaining a thick-film resistor having a dimensional stability, which is caused by a complicated step of increasing the process, which causes an increase in cost. In addition, Changxing Chemical also proposed a patent for resistive materials (cn丨567485) in 2005.

Emphasis is placed on the insoluble (four) system, the completed thick film resistor has good dimensional stability and good rheological properties, but the resistance stability is still not perfect. SUMMARY OF THE INVENTION The present invention discloses a pre-reactive polymer/nano powder mixed material having good resistance stability, wherein a polymer epoxy resin-based formulation is prepared by adding a nano conductor and pre-forming The reaction process improves the instability of the resistance and takes into account the feasibility and material properties of the PCB process. The polymer thick film resistor material of the present invention has high glass transition temperature, small error variability, and excellent film thickness stability, and can be applied to applications of buried resistor materials. The raw materials used include (4)-epoxy resin system comprising a high-functional epoxy resin having a functional group of 4 or more; (b) conductive powder (for example, carbon black) having at least one particle size distribution And comprising a nano-powder; and (c) a polymeric dispersant. The above polymer thick film resistor composition can be produced by the following steps. First, a mixed epoxy resin system and at least one conductive powder, wherein the epoxy resin system comprises a south functional epoxy resin having a functional group of 4 or more, and the J-oxygen resin system and the conductive powder are 100 The temperature of -140 〇c is heated for 3 minutes to 5 hours for pre-reaction. After the addition of the hardener and the catalyst, the temperature is lowered, 100210-116389 005936987-1 200828344 and:: Gao Guangzi: a dispersant, which is dispersed through three rollers to obtain a resistor paste. 'Cheng's mouth, the present invention discloses a material formulation technique that is not mentioned in the previous case, that is, the pre-added resistance material has an excellent electric film to emphasize the thick film capacity. The means used include (2nd, 2nd, and C. Mens also include (1) choose the appropriate epoxy resin composition to balance the flame resistance and then the half of the thumb ( )% of the money filled with nano type and Second, 冋W raw powder to adjust its resistance value; and (7) choose appropriate

: With the knife-type dispersant, _ can improve the low heat resistance of low molecular type dispersibility, and improve the reliability of future product application. The principle is mainly that it can be easily attached by special polymer type dispersant. It has excellent compatibility with the organic resin on the surface of the helmet powder and even a few reaction seats can effectively solve the shortcomings of the low molecular type dispersant, and utilizes the pre-reaction process to improve the resistance stability of the material. The obtained resistive paste has a high glass transition temperature (dg>15〇c>c), excellent resistance stability and small error variation through screen printing technology and low temperature hardening temperature. Resistance material (T〇lerance ^ 6%). In particular, the application of resistive materials has been quite extensive, but the general process is still dominated by two-temperature sintering, which is difficult to apply to organic substrates or traditional PCB processes. If polymer/nanoconductor hybrid materials are used, polymers are used. The compatibility of the resin material with the substrate can be achieved by using a general substrate or a pCB process to complete the fabrication of the buried resistor. In order to make the polymer/nanoconductor hybrid material have good characteristics, including electrical stability and thermal stability, it can be basically determined by the choice of the tree 曰 system and screen printing technology; such as low temperature hardening, high temperature stability Good' and good adhesion between the steel layer and the dielectric layer and the substrate 100210-116389 005936987-1 -9- 200828344, etc., must be achieved by the choice of resin system, and the conductive properties required by the material must be Adding nano-conductive powder to provide, as for the electrical stability, it must be achieved through a special pre-reaction process, in order to produce a polymer/nai that combines both low-temperature processability and resistance stability of the resin. Rice conductor hybrid material. Since the demand for buried resistor substrates is mainly applied to high-frequency and high-speed electronic products, the demand for thermal properties and electrical properties is gradually increasing. Therefore, the disclosed pre-reactive polymer/nanoconductor hybrid materials are not only important. In addition to the accuracy of the value, it is also necessary to pay attention to both the thermal properties and the stability of the electrical properties. Therefore, the formulation of the material formulation ratio, the control of the process conditions, and the technology of screen printing are the focus of the present invention. [Embodiment] The raw material of the polymer thick film resistor composition of the present invention may be selected as follows:

(b) Diglycidyl ether of bisphenol A epoxy (c) Tetrabronio bisphenol A diglycidyl ether epoxy (d) A cyclic aliphatic epoxy resin (Cyclo aliphatic epoxy 100210-116389 005936987-1 -10- 200828344 resin). For example: dicyclopentadiene epoxy resin 〇 (e) Naphthalene epoxy resin. (f) Diphenylene epoxy resin. (g) Phenol Novolac epoxy resin (h) O-cresol Novolac epoxy resin Hardener (a) Diamine: H2N —Ri — NH2 Φ Ri It may be an aromatic group, a fat group, a cycloaliphatic group or a silane-containing aliphatic group, etc., for example:

R2: X, ch2, S02, 0, s, c(ch3)2 r3~r1(): h,ch3, c2h5, c3h7, c(ch3)3,... (b) phenol resin (Phenol based resin), for example:

Naphthol based resin, for example

OH OH 100210-116389 005936987-1 -11- 200828344

Dicyclopentadiene resin

4,4',4"Ethylenetriphenol (4,4,,4" Etliylideiietrisphenol)

OH

Tetra phenylolethane

HO OH

HO 〇H Tetraxylenol ethane

Tetracresololethane 100210-116389 005936987-1 -12- 200828344

Catalyst (a) Cationic catalyst boron trifluoride complex, such as RNH2 · BF3, R2NH · BF3, R3N · BF3, etc. (b) Anionic catalyst _ tertiary amine, metal hydroxide, monoepoxide Coordination anion catalysts, such as R3N, TMG, NCH2C-C(NH)-N(CH3)2, etc. (c) Imidazole 1 -methylimidazole 1,2-dimethyl 1,2-dimethylimidazole 2-heptadecylimidazole 2-ethyl-4-methylimidazole Dispersant® High in the present invention The molecular type dispersant has good adhesion and dispersibility with the inorganic powder, and has excellent compatibility and dispersibility with the organic resin. Polymer dispersants which can be used include copolyesters, guanamines, polyesters and the like. Conductive powders are mainly highly conductive powders, such as · metal powders (such as gold, silver, copper, Ilu, silver iridium alloys, etc.), metal oxides (such as silver oxide, oxidized...etc.), carbon Black, graphite, etc. 100210-116389 005936987-1 -13- 200828344 The technology of the present invention will be exemplified below, and the material content thereof is shown in Table 1, wherein Epoxy 1 is bisphenol-A diglycidyl ether. Epoxy 2 is tetrabromo disphenol-A diglcidyl ether, and Epoxy 3 is a cyclo aliphatic epoxy. Epoxy 4 is a multifunctional epoxy having the following chemical formula and having a functional group of 4 or more.

Table 1 Composition Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Pre-reaction without Epoxy 1 (g) 7.11 7.1 7.0 6.93 6.93 Epoxy 2(g) 4.44 4.44 4.38 4.33 4.33 Epoxy 3 (g) 1.24 1.24 1.22 1.21 1.21 Epoxy 4 (g) 1.78 1.77 1.75 1.73 1.73 Hardener (g) 3.36 3.36 3.31 3.28 3.28 Catalyst (g) 0.0626 0.0625 0.062 0.061 0.061 Dispersant 1 (g) 0.513 0.513 0.51 0.51 0.51 black (g) 4.04 4.06 4.04 3.88 4.08 silver plate (g) 0 0 0 29 30 The epoxy resin accounts for 30~80% by weight of the total solid content, the carbon black accounts for 5~20% by weight of the total solid powder, and the polymer dispersant accounts for The total solid powder is 0. 5 to 5% by weight. The hardener accounts for 3-20% by weight of the total solid powder. Further, in Examples 1 to 4, the silver flakes accounted for 0-60% by weight of the total solid powder. The manufacturing procedure of the examples in Table 1 is as follows, except that the comparative example does not perform the pre-reaction process of step 3 of the following 100210-116389 005936987-1 -14-200828344. 1. Epoxy Epoxy 1~4 and solvent are placed in a reaction flask and heated to 90~95 °C for mixing. 2. Add an appropriate amount of highly conductive powder to the above solution, and then mix it at high speed to form a mixed solution. The amount of the south conductive powder added is about 5 to 65% by weight based on the total solid powder. 3. The above mixed solution is pre-reacted at a high temperature of 100 to 140 ° C for about 30 minutes to 5 hours, and then lowered to 80 ° C, and an appropriate amount of a hardener and a catalytic agent are added to fully dissolve and then lowered to room temperature. 4. Take an appropriate amount of epoxy resin mixture solution and add appropriate amount of dispersant and other conductive powder (add as needed). 5. The obtained mixture was dispersed in three rolls to obtain a well-dispersed mixed resistance resin. 6. The above-mentioned mixed resistive paste is printed by a screen printing process to form a resistor at a position having a pattern. 7. After the electrical resistance measured by the electrical measurement, the resistance range obtained from the difference of the material composition is about 35 Ω~1.5 kD. 8. In the thermal property test, the Tg of the resistance component is in the range of 150 to 190 °C. In particular, first add an appropriate amount of epoxy resin to the reaction flask, and then add an appropriate amount of solvent BC (Diethylene Glycol Monobutyl ether) and Dimethyl formamide (DMF). Then, heating to 90 ° C ~ 95 ° C allows the epoxy resin to completely dissolve and cool. Adding an appropriate amount of conductive powder to the above solution and then uniformly dispersing it at a south speed, and performing a pre-reaction or a non-reaction method at a high temperature, and then adding a suitable amount of a hardening agent such as a double after cooling down 100210-116389 005936987-1 -15 - 200828344 The amine or the resin and the catalyst are fully dissolved and then lowered to room temperature. The polymer/conductive powder mixture solution prepared beforehand is added, and an appropriate amount of the polymer type dispersant (dispersant 1) is added. Then, if the conductivity is insufficient, an appropriate amount of the conductive powder (such as carbon black, particle size 10~) may be added. 1 OOnm ), silver plate (1~10 μπι) or other additives, uniformly stirred and dispersed by three rollers to form a polymer/conductive powder mixed slurry, and printed on a fixed pattern by wire mesh screen printing method, The solvent is removed by heat baking and cross-linked to form a thick film resistor. The manufacturing process of the thick film resistor of the present invention can be summarized as shown in Fig. 1. The test results of the thick film resistor are shown in Table 2, wherein the glass transition temperature (Tg) is measured by a Thermo Mechanical Analyzer (TMA). Table 2 Characteristics Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Tg (°C) 171 172 175 177 178 Resistance (Ω) 746~1041 827~898 768~832 39.17 ~42.69 38.05~41.95 Variability ( +18.08, -15.38) (+3.67, -4.53) (+3.29, -4.66) (+5.32, -3.36) (+6.03, -3.82) # Comparative Example 1 is a preheating reaction process in which the components are contained. The ratios of the first embodiment and the second embodiment are substantially the same, but the resistance value variability (Tolerance) after screen printing differs greatly because the preheating reaction process promotes the reaction of the nano powder with the epoxy moiety structure. A molecular structure having a large molecular weight and a relatively stable structure is formed. Further, in the third embodiment and the fourth embodiment, a formulation in which two kinds of conductive powders are added (in which the carbon black has a particle diameter of 10 to 100 nm and a silver plate particle diameter of 1 to 10 μπι) is subjected to a pre-reaction process, which is The resistance material has a small resistance value variability except for a small resistance value. 100210-116389 005936987-1 -16- 200828344 It is known from the above results that in order to obtain a high-stability resistance polymer/conductive powder hybrid material, the formulation must contain at least one high-functional epoxy resin. A polymer type dispersant and at least one conductive powder having a nanometer particle size can be used to obtain a kind of embedded resistance material which is truly useful. The technical contents and technical features of the present invention have been disclosed as above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is not limited by the scope of the invention, and the invention is intended to cover various modifications and alternatives. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a manufacturing process of a polymer thick film resistor composition of the present invention. [Main component symbol description] None 100210-116389 005936987-1 -17-

Claims (1)

200828344 X. Patent application scope: 1 · A polymer thick film resistor consisting of: - a silicone resin system comprising an epoxy resin having a functional group of 4 or more; at least one conductive powder having an average particle size of 1〇~1〇〇nm; a hardener; and a polymer dispersant; by using the oxygen resin system, the polymer thick film resistor composition φ glass transition temperature is at least 15 (TC. 2. According to The request item has a polymer thick film resistor composition, and the epoxy resin comprises the following chemical structure: 3. The polymer thick film resistor composition according to claim 1, wherein the epoxy resin system further comprises at least a bisphenol A type epoxy resin, a cyclic aliphatic epoxy resin, a naphthalene ring-containing epoxy resin, and a diphenyl ring. Oxygen resin or phenolic epoxy resin. 4. The polymer thick film resistor composition according to claim 1, wherein the epoxy resin system further comprises bisphenol diglycidyl ether epoxy resin, tetrabromobisphenol diglycidyl ether epoxy resin, and cyclic aliphatic epoxy Resin. 5. The polymer thick film resistor composition according to claim 1, wherein the epoxy resin system accounts for 30 to 80% by weight of the total solid content. 6. The polymer thick film resistor composition according to claim 1, wherein the conductive powder contains two or more particle size distributions. I〇〇2i〇-n6389 0〇5936987-i 200828344 7. The polymer thick film resistor composition according to claim 1, wherein the conductive powder is selected from the group consisting of silver powder, carbon black, and graphite. 8. The polymer thick film resistor composition according to claim 1, wherein the conductive powder accounts for 5-65% by weight of the total solid powder. 9_ According to the request item, the polymer thick film resistor composition, wherein the conductive powder is carbon black. 10_ The polymer thick film resistor composition according to claim 9, wherein the carbon black accounts for 5 to 20 Å/〇 of the total solid powder. The polymer thick film resistor composition according to claim 9, wherein the conductive powder further comprises a silver flake and an average particle diameter of bWpm. 12. The polymer thick film resistor composition according to the claim, wherein the silver sheet comprises 0-60% by weight of the total solid powder. 13. The polymer thick film resistor composition according to the claim, wherein the polymer dispersant is selected from the group consisting of copolyester-melamine and polyester. 14. According to the request item! The composition of the polymer thick film resistor, wherein the polymer dispersant accounts for 总.5~5 〇/ of the total solid powder. The weight percentage. 15. The polymer thick film resistor composition according to the claim, wherein the hardener comprises 3-20% by weight of the total solid powder. The polymer thick film resistor composition according to claim 15, wherein the hardener is selected from the group consisting of a diamine, a resin, and an acid anhydride. 17. The polymer thick film resistor composition according to the claim ,, wherein the epoxy resin system and the conductive powder system are first mixed and pre-reacted at a temperature of from 1 to 14 (rCi temperature for 30 minutes to 5 hours. According to the composition of the polymer thick film resistor of claim 1, it can be applied to a buried resistive element for a printed circuit board or a 1C substrate by screen printing 200828344. 19 · Molecular thick film according to the claim 1 The composition of the resistor further comprises a catalyst. 20. The composition of the south molecular thick film resistor according to claim 19, wherein the catalyst is selected from the group consisting of a cationic catalyst, an anionic catalyst, and a saliva. 21 · The manufacturing method of the polymer thick film resistor composition comprises the following steps: mixing an epoxy resin system and at least one conductive powder, wherein the epoxy resin system has a polymer thick film resistor having a capacitance of at least 15 〇 ° C The glass transition temperature 'and contains a bad oxygen resin' having a functional group of 4 or more; heating the epoxy resin system and the conductive powder for pre-reaction; cooling after adding a hardener; and adding a polymer dispersion The agent is used to prepare a resistive paste. 22. The method according to claim 21, wherein the epoxy resin system and the conductive powder system are heated at a temperature of 100-14 ° C for 30 minutes to 5 hours. The pre-reaction is carried out. 23. The method for producing a polymer thick film resistor composition according to claim 21, further comprising the step of producing a thick film resistor by screen printing the film according to claim 21. A method for fabricating a molecular thick film resistor composition, wherein a conductive powder is added again after cooling. 25. The method for fabricating a polymer thick film resistor composition according to claim 21, wherein the epoxy resin system comprises the following chemical structure: 100210- 116389 005936987-1 200828344 ^fr. The method for producing a thick film resistor composition of a commercial molecule, wherein the resin system further comprises at least a double-presence A type epoxy resin, a cyclic fat surface % oxygen resin, a naphthalene ring epoxy resin, a double phenyl ring Oxygen resin or ageing epoxy resin. 27. The method of producing a polymer thick film resistor composition according to claim 21, wherein the epoxy resin system comprises 3 to 8% by weight of the total solid powder. 28. The method according to claim 21, wherein the V-coated powder system is selected from the group consisting of silver powder, carbon black and graphite. The method for producing a polymer thick film resistor composition according to claim 21, wherein the electric powder system is black and has an average particle diameter of from 1 〇 to 1 〇〇 nm. 3. The method for producing a polymer thick film resistor composition according to claim 29, wherein the conductive powder further comprises a silver flake and an average particle diameter of 31. The method for preparing a polymer thick film resistor composition according to claim 30, wherein the silver sheet accounts for 0% to 60% by weight of the total solid powder, and the carbon black accounts for 5 to 20% by weight of the total solid powder. . The method for producing a polymer thick film resistor composition according to claim 21, wherein the polymer dispersant accounts for 5 to 5% by weight of the total solid powder. 100210-116389 005936987-1