Resin composition and dielectric layer and capacitor produced therefrom

Abstract

The present invention provides a resin composition comprising: 1 to 20 parts by weight of a reinforcing fiber; 0.2 to 5 parts by weight of an anti-settling agent; 20 to 40 parts by weight of an epoxy resin; 0.1 to 3 parts by weight of a curing agent; and 50 to 75 parts by weight of a high dielectric constant filler. The present invention further provides a dielectric layer produced from the resin composition and a capacitor comprising the dielectric layer. In the dielectric layer made from the resin composition provided by the present invention, the fibers can be evenly dispersed and can enhance the mechanical strength of the resin composition, and cooperate with the epoxy resin to bring excellent toughness. Therefore, the mechanical strength of the produced dielectric layer can be remarkably improved, and its fragility can be effectively overcome when the dielectric layer is used in the PCB double-side etching process.

Claims

1. A dielectric layer comprising a cured product of a resin composition, the resin composition comprising components: a) 1 to 20 parts by weight of a reinforcing fiber; b) 0.2 to 5 parts by weight of an anti-settling agent; c) 50 to 75 parts by weight of a high dielectric constant filler; d) 0.1 to 3 parts by weight of a curing agent; and e) 20 to 40 parts by weight of an epoxy resin, wherein a combined weight of components a) to e) equals 100 parts by weight.

2. The dielectric layer of claim 1, wherein the high dielectric constant filler is barium titanate having a diameter in a range of 0.1 to 2 μm.

3. The dielectric layer of claim 1, wherein the reinforcing fiber is one or more of alkali-free glass fiber powders and potassium titanate whiskers and has a diameter of 0.1 to 10 μm and a length of 10 to 400 μm.

4. A capacitor laminate comprising a dielectric layer disposed between first and second conductive substrates, wherein the dielectric layer comprises a cured product of a resin composition, the resin composition comprising components: a) 1 to 20 parts by weight of a reinforcing fiber; b) 0.2 to 5 parts by weight of an anti-settling agent; c) 50 to 75 parts by weight of a high dielectric constant filler; d) 0.1 to 3 parts by weight of a curing agent; and e) 20 to 40 parts by weight of an epoxy resin, wherein a combined weight of components a) to e) equals 100 parts by weight.

5. The capacitor laminate of claim 4, wherein at least one of the first and second conductive substrates comprises a metal foil.

6. The capacitor laminate of claim 5, wherein the metal foil is an electrolytic copper foil.

7. The capacitor laminate of claim 6, wherein the electrolytic copper foil has a roughness Rz less than 5 μm.

8. The capacitor laminate of claim 4, wherein the dielectric layer has a total thickness of 1 to 50 μm.

9. The capacitor laminate of claim 4, wherein the reinforcing fiber is selected from one or more of glass fibers, carbon fibers, organic polymer short cut fibers and inorganic whiskers.

10. The capacitor laminate of claim 4, wherein the reinforcing fiber has a diameter of 0.1 to 10 μm and a length of 5 μm to 3 mm.

11. The capacitor laminate of claim 4, wherein the reinforcing fiber is one or more of alkali-free glass fiber powders and potassium titanate whiskers and has a diameter of 0.1 to 10 μm and a length of 10 to 400 μm.

12. The capacitor laminate of claim 4, wherein the anti-settling agent comprises fumed silica, and wherein the fumed silica has a specific surface density of 120 to 250 g/m.sup.2 and has been surface-treated with a hydrophobic agent.

13. The capacitor laminate of claim 4, wherein the epoxy resin comprises one or more of bisphenol-A epoxy resin, bisphenol-F epoxy resin, bisphenol-S epoxy resin, phenolic novolac epoxy resin and o-cresol novolac epoxy resin.

14. The capacitor laminate of claim 13, wherein the high dielectric constant filler is selected from one or more of barium titanate, strontium titanate, barium strontium titanate, calcium barium titanate, calcium lead titanate ceramic, lead titanate-lead magnesium niobate, carbon black, carbon nanotubes, metals and metal oxides.

15. The capacitor laminate of claim 4, prepared by: coating a surface of the first conductive substrate with the resin composition; drying the coating; laminating the second conductive substrate to the first conductive substrate, such that the first and second conductive substrates are thermally bound to each other with the coating being sandwiched there between; and curing the coating.

16. The capacitor laminate of claim 4, prepared by: coating a surface of the first conductive substrate with the resin composition; coating a surface of the second conductive substrate with the resin composition; drying the coatings; laminating the second conductive substrate to the first conductive substrate, such that the first and second conductive substrates are thermally bound to each other with the coatings being sandwiched there between; and curing the coatings.

Description

EXAMPLES

(1) The following raw materials were used for experiments in the examples of present invention.

(2) Raw Materials:

(3) Reinforcing fiber: potassium titanate whiskers (diameter: 0.5-1 μm; length 10-50 μm), Shenyang Jinjian Short cut Fiber Composite Material Co., Ltd.

(4) Alkali-free glass fiber powders (diameter: 9 μm; length 10-200 μm), Hangzhou Gaoke Composite Material Co., Ltd.

(5) Anti-settling agent: fumed silica, HB-620, Guangzhou Jibisheng Technology Co., Ltd.

(6) Dispersant: Solsperse 76500, Lubrizol Specialty Chemicals (Shanghai) Co., Ltd.

(7) Epoxy resin: GT6097, Huntsman Advanced Materials (Guangdong) Co., Ltd.

(8) Curing agent: electronic-grade dicyandiamide, Ningxia Darong Chemical Metallurgy Co., Ltd.

(9) Terminal tertiary amine group-containing hyperbranched polyester, QNP1 4135, Shanghai Wujing Chemical Engineering Science and Technology Co., Ltd.

(10) High dielectric constant filler: barium titanate BT-101s, Shanghai Dianyang Co., Ltd.

(11) Methyl ethyl ketone: chemical pure grade, Shanghai Xiangxun Fine Chemical Reagent Co., Ltd.

Example 1

(12) A resin composition comprising 1 part by weight of potassium titanate whiskers, 0.3 part by weight of fumed silica HB-620, 35 parts by weight of epoxy resin GT6097, 0.3 part by weight of dicyandiamide and 63.4 parts by weight of barium titanate is prepared. Specifically, 634 g of barium titanate BT-101s and 10 g of potassium titanate whiskers were added into 360 g of Methyl ethyl ketone and the resulting mixture was sheared at high speed until it was evenly dispersed; 3 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 350 g of epoxy resin GT6097 and 3 g of dicyandiamide dissolved in 125 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1485 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(13) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for about 3 minutes until it was in a semi-cured state, thereby a laminate of the dielectric layer and the copper foil was obtained. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(14) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for about 2 hours so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 2

(15) A resin composition comprising 3 parts by weight of potassium titanate whiskers, 1 part by weight of fumed silica HB-620, 34 parts by weight of epoxy resin GT6097, 0.3 part by weight of dicyandiamide and 61.7 parts by weight of barium titanate was prepared. Specifically, 617 g of barium titanate BT-101s and 30 g of potassium titanate whiskers were added into 360 g of Methyl ethyl ketone and the resulting mixture was sheared at high speed until it was evenly dispersed; 10 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 340 g of epoxy resin GT6097 and 3 g of dicyandiamide dissolved in 120 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1480 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(16) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(17) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for about 2 hours so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 3

(18) A resin composition comprising 3 parts by weight of potassium titanate whiskers, 1 part by weight of fumed silica HB-620, 34 parts by weight of epoxy resin GT6097, 0.3 part by weight of dicyandiamide and 61.7 parts by weight of barium titanate was prepared. Specifically, 617 g of barium titanate BT-101s and 30 g of potassium titanate whiskers were added into 360 g of Methyl ethyl ketone and the resulting mixture was sheared at high speed until it was evenly dispersed; 10 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 340 g of epoxy resin GT6097 and 3 g of dicyandiamide dissolved in 120 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1480 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(19) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 50 μm as determined by a micrometer.

(20) Next, the laminate of the dielectric layer and the electrodeposited copper foil and an electrodeposited copper foil without a dielectric layer were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min with the dielectric layer sandwiched between the two electrodeposited copper foils. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for about 2 hours so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 4

(21) A resin composition comprising 6 parts by weight of potassium titanate whiskers, 2 parts by weight of fumed silica HB-620, 32 parts by weight of epoxy resin GT6097, 0.3 part by weight of dicyandiamide and 59.7 parts by weight of barium titanate was prepared. Specifically, 10 g of dispersant Solsperse 76500 was added into 360 g of Methyl ethyl ketone and stirred until complete dissolution, and then 597 g of barium titanate BT-101s and 60 g of potassium titanate whiskers were added thereto and the resulting mixture was sheared at high speed until it was evenly dispersed; 20 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 320 g of epoxy resin GT6097 and 3 g of dicyandiamide dissolved in 112 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1482 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(22) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(23) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for 2 h so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 5

(24) A resin composition comprising 9 parts by weight of potassium titanate whiskers, 3 parts by weight of fumed silica HB-620, 29 parts by weight of epoxy resin GT6097, 1 part by weight of curing agent QNP1 4135 and 58.7 parts by weight of barium titanate was prepared. Specifically, 10 g of dispersant Solsperse 76500 was added into 360 g of Methyl ethyl ketone and stirred until complete dissolution, and then 587 g of barium titanate BT-101s and 90 g of potassium titanate whiskers were added thereto and the resulting mixture was sheared at high speed until it was evenly dispersed; 30 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 290 g of epoxy resin GT6097 and 10 g of curing agent QNP1 4135 dissolved in 100 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1477 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(25) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(26) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for 2 h so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 6

(27) A resin composition comprising 9 parts by weight of alkali-free glass fiber powders, 3 parts by weight of fumed silica HB-620, 29 parts by weight of epoxy resin GT6097, 1 part by weight of curing agent QNP1 4135 and 58.7 parts by weight of barium titanate was prepared. Specifically, 10 g of dispersant Solsperse 76500 was added into 360 g of Methyl ethyl ketone and stirred until complete dissolution, and then 587 g of barium titanate BT-101s and 90 g of alkali-free glass fiber powders were added thereto and the resulting mixture was sheared at high speed until it was evenly dispersed; 30 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 290 g of epoxy resin GT6097 and 10 g of curing agent QNP1 4135 dissolved in 100 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1477 g of an alkali-free glass fiber powders-reinforced epoxy resin composition solution.

(28) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(29) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for 2 h so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Example 7

(30) A resin composition comprising 20 parts by weight of potassium titanate whiskers, 5 parts by weight of fumed silica HB-620, 20 parts by weight of epoxy resin GT6097, 0.2 part by weight of dicyandiamide and 54.8 parts by weight of barium titanate was prepared. Specifically, 548 g of barium titanate BT-101s and 200 g of potassium titanate whiskers were added into 360 g of Methyl ethyl ketone and the resulting mixture was sheared at high speed until it was evenly dispersed; 50 g of fumed silica HB-620 was further added thereto and the mixture was sheared at high speed until it was evenly dispersed; and 200 g of epoxy resin GT6097 and 2 g of dicyandiamide dissolved in 75 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1435 g of a potassium titanate whiskers-reinforced epoxy resin composition solution.

(31) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(32) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for 2 h so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

Comparative Example A

(33) A resin composition comprising 36 parts by weight of epoxy resin GT6097, 0.3 part by weight of dicyandiamide and 63.7 parts by weight of barium titanate was prepared. Specifically, 637 g of barium titanate BT-101s was added to 360 g of Methyl ethyl ketone and the resulting mixture was sheared at high speed until it was evenly dispersed; and 320 g of epoxy resin GT6097 and 3 g of dicyandiamide dissolved in 112 g of Methyl ethyl ketone were finally added and the mixture was evenly stirred so as to obtain 1472 g of an epoxy resin composition solution.

(34) The resulting solution was coated on a copper foil (CF-TGFB-DSTF-THE-18μ, Suzhou Fukuda Metal Co. Ltd.) by a Mayer bar; the copper foil coated with the solution was then dried by heating at 150° C. for 3 min until it became a semi-cured state, thereby obtaining a laminate of the dielectric layer and the copper foil. The dielectric layer in the laminate of the dielectric layer and the electrodeposited copper foil had a thickness of 25 μm as determined by a micrometer.

(35) Next, the dielectric layers of two laminates of the dielectric layer and the electrodeposited copper foil were thermally bound to each other by heat rollers at a laminating temperature of 180° C., a laminating pressure of 5 Kgf/cm.sup.2 and a laminating rate of 1 m/min. After completing the laminating, the bound product was placed into an oven at 160° C. and cured for about 2 hours so as to produce an embedded capacitor. The thickness of the dielectric layer in the embedded capacitor was 50 μm.

(36) The embedded capacitors obtained in the examples 1-7 and comparative example A were tested in terms of glass transition temperature, solder float resistance, mechanical strength (initial tearing strength), capacitance density and compatibility with PCB double-side etching process according to the testing methods described in the present invention. The testing results are shown in Table 1.

(37) TABLE-US-00001 TABLE 1 Example Example Example Example Example Example Example Comparative 1 2 3 4 5 6 7 example A glass transition 115 115 115 117 117 120 123 115 temperature(Tg), ° C. Solder float >5 min. >5 min. >5 min. >5 min. >5 min. >5 min. >5 min. >5 min. resistance, 288° C. initial tearing 110 140 140 150 180 200 110 100 strength, g (thickness of medium was 50 μm) capacitance 2.4 2.4 2.4 2.4 2.3 2.3 2.3 2.4 density, nf/in.sup.2 compatibility with Δ Δ Δ Δ ○ ○ Δ □ PCB double-side etching process

(38) As shown from data in Table 1, with the help of the reinforcing fibers, the tearing strength of the dielectric layer is greatly improved and increased with increased loading of the reinforcing fibers, but would decrease to a certain extent with further increased loading of the reinforcing fibers, mainly because the reinforcing fibers are not sufficiently contacted with the epoxy resin at the interface with further increased loading. The tearing strengths of the most preferable examples 5 and 6 of the present invention are almost 2 times higher than that of comparative example A, which indicates that the introduction of a certain amount of reinforcing fibers can markedly improve the tearing strength of the dielectric layer of the embedded capacitor and cooperate with the epoxy resin having excellent toughness to provide outstanding synergistic effect. Therefore, the fragility of the thin material in the actual PCB double-side etching process can be effectively avoided while maintaining the relatively high capacitance density and remarkable heat resistance.