CN106128543B - Conductive silver paste with good anti-settling effect and preparation method thereof - Google Patents
Conductive silver paste with good anti-settling effect and preparation method thereof Download PDFInfo
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- CN106128543B CN106128543B CN201610565136.6A CN201610565136A CN106128543B CN 106128543 B CN106128543 B CN 106128543B CN 201610565136 A CN201610565136 A CN 201610565136A CN 106128543 B CN106128543 B CN 106128543B
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- silver paste
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
Abstract
The invention discloses a conductive silver paste with good anti-settling effect and a preparation method thereof, wherein the conductive silver paste comprises the following components in parts by weight: 75-85 parts of flake silver powder, 6-10 parts of epoxy resin, 1-3 parts of phthalic anhydride, 0-1 part of tetraethyl titanate, 0.2-0.8 part of sodium dodecyl sulfate and 0.05-0.5 part of sodium dodecyl benzene sulfonate, and the preparation method comprises the following steps: preparing flake silver powder, preparing conductive slurry and performing anti-settling treatment. According to the invention, sodium dodecyl sulfate and sodium dodecyl benzene sulfonate are added into the prepared silver paste as dispersing agents, so that the precipitation of the silver powder in the organic resin is effectively inhibited, and the dispersing agents play a role in stabilizing the paste through steric hindrance or an electrostatic mechanism.
Description
Technical Field
The invention relates to conductive silver paste and a preparation method thereof, in particular to conductive silver paste with good anti-settling effect and a preparation method thereof.
Background
The silver paste is a medium-low temperature conductive paste, and is a composite material formed by uniformly mixing single silver powder and resin liquid. The curing temperature is low, the stability and the conductivity are good, and the adhesive force is good, so that the curing agent is mainly applied to forming a conductive, resistive, insulating film and the like on a non-conductive substrate. The CSP-3163CSP-3310 series silver paste of Korea Changxing company has stable product performance, excellent printing performance, adhesion and elasticity, low resistance coefficient and clear linear resolution. The conductive silver paste produced by Shenzhen Nabo electronic material Limited company has the characteristics of excellent functionality, high cost performance and the like. The flexible printed circuit board is widely applicable to various industries such as a film switch, a flexible circuit, an FPC (flexible printed circuit), a toy circuit, a remote controller, a printed circuit board and the like.
Currently, silver paste mainly consists of conductive fillers, organic resin and additives. The silver powder is used as a main component in the dipping silver paste, and the powder is very easy to agglomerate among particles due to the large specific surface area, the large number of surface atoms, the high surface energy, the large number of surface defects and dangling bonds, so that an agglomerate with a large size is formed, and the development and application of the product are influenced.
Disclosure of Invention
The invention aims to provide conductive silver paste with a good anti-settling effect and a preparation method thereof. The slurry has better dispersibility, anti-settling effect, stability and conductivity.
The technical scheme of the invention is as follows: the conductive silver paste with good anti-settling effect comprises the following components in parts by weight: 75-85 parts of flake silver powder, 6-10 parts of epoxy resin, 1-3 parts of phthalic anhydride, 0-1 part of tetraethyl titanate, 0.2-0.8 part of sodium dodecyl sulfate and 0.05-0.5 part of sodium dodecyl benzene sulfonate.
The conductive silver paste with good anti-settling effect comprises the following components in parts by weight: 80 parts of flake silver powder, 8 parts of epoxy resin, 2 parts of phthalic anhydride, 0.5 part of tetraethyl titanate, 0.3 part of sodium dodecyl sulfate and 0.1 part of sodium dodecyl benzene sulfonate.
In the conductive silver paste with a good anti-settling effect, the epoxy resin is bisphenol a epoxy resin E55 or E51.
The preparation method of the conductive silver paste with the good anti-settling effect comprises the following steps:
(1) preparing flake silver powder: first AgNO3Prepared into an aqueous solution to AgNO3Adding surfactant into the aqueous solution, heating the reducing agent solution to 50 deg.C and adjusting pH to 13, and adding surfactant AgNO3Mixing the aqueous solution and the reducing agent solution for reaction, filtering, washing with deionized water, washing with absolute ethyl alcohol, and drying to obtain the flake silver powder;
(2) preparing conductive slurry: heating the epoxy resin to 80-90 ℃, then directly adding the flake silver powder prepared in the step (1) into the heated epoxy resin, uniformly stirring, then adding phthalic anhydride and tetraethyl titanate, and uniformly stirring to form conductive slurry;
(3) anti-settling treatment: and (3) adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate into the silver paste prepared in the step (2), and stirring and pre-dissolving to obtain the conductive silver paste with good anti-settling effect.
In the preparation method of the conductive silver paste with the good anti-settling effect, in the step (1), the surfactant is cetyl trimethyl ammonium bromide, and the addition amount of the surfactant is 0.1% of the total amount.
In the preparation method of the conductive silver paste with a good anti-settling effect, in the step (1), the reducing agent solution is an ascorbic acid aqueous solution.
In the preparation method of the conductive silver paste with a good anti-settling effect, in the step (2), the heating temperature of the epoxy resin is 85 ℃.
In the preparation method of the conductive silver paste with good anti-settling effect, in the step (2) and the step (3), ultrasonic dispersion treatment is adopted during stirring and mixing.
In the preparation method of the conductive silver paste with good anti-settling effect, the average diameter of the flake silver powder prepared in the step (1) is 2-5 micrometers.
The invention has the beneficial effects that: according to the invention, the sodium dodecyl sulfate and the sodium dodecyl benzene sulfonate are added into the prepared silver paste as the dispersing agents, so that the precipitation of the silver powder in the organic resin is effectively inhibited, and the stability and the dispersity of the conductive silver paste are improved, thereby improving the conductive effect of the silver paste, and the dispersing agents play a role in stabilizing the paste through steric hindrance or an electrostatic mechanism.
To further illustrate the beneficial effects of the present invention, the inventors made the following experiments:
experimental example 1: effect of dispersant addition on silver paste stability
Taking two groups of conductive silver paste which are prepared by the method and are not subjected to anti-settling treatment, adding the Sodium Dodecyl Sulfate (SDS) and the Sodium Dodecyl Benzene Sulfonate (SDBS) into one group, and performing anti-settling treatment by using the method, wherein the conductive silver paste is marked as an SDS + SDBS group; the other group was not processed and was designated as the original group. The stability of the conductive silver paste is characterized by measuring the RSH of the two groups of conductive silver pastes within 300h respectively. The results are shown in FIG. 1.
Remarking: RSH is the Ratio of the supernatant height H to the total slurry height H during settling (RSH). From the formula (1), the total height H of the same volume of the slurry is unchanged, and the larger the settled clear liquid is, the larger the H value is, the larger the RSH value is, and the more unstable the silver slurry is.
As can be seen from fig. 1, the RSH values of the two sets of conductive silver pastes are the original set > SDS + SDBS set, and thus, the stability of SDS + SDBS set > the stability of the original set, at any settling time.
Experimental example 2: effect of different dispersant concentrations on silver paste stability
Taking four groups of conductive silver pastes which are prepared by the method and are not subjected to anti-settling treatment, adding Sodium Dodecyl Sulfate (SDS) and Sodium Dodecyl Benzene Sulfonate (SDBS) with different weight components into the four groups of conductive silver pastes according to the method of the invention, wherein the weight components of the Sodium Dodecyl Sulfate (SDS) and the Sodium Dodecyl Benzene Sulfonate (SDBS) added into the four groups of conductive silver pastes are as follows: the RSH values of the conductive silver pastes were measured after the treatments were completed, respectively, for SDS + SDBS (0.3 parts +0.1 parts), SDS + SDBS (0.8 parts +0.5 parts), SDS + SDBS (0.3 parts +0.5 parts), and the results are shown in fig. 2, and it can be seen from fig. 2 that the RSH value was the lowest when the concentrations of SDS + SDBS were (0.3 parts +0.1 parts), indicating that the stability of the conductive silver pastes was the best after the SDS + SDBS was added.
Experimental example 3: SEM measurement
A group of the conductive silver paste which is prepared by the method and is not subjected to anti-settling treatment and a group of the conductive silver paste which is prepared by the method and is subjected to anti-settling treatment are selected and subjected to SEM measurement respectively, and the obtained SEM images are respectively shown in the attached drawings 3 and 4.
Comparing fig. 3 and fig. 4, it can be seen that the silver powder particles of the conductive silver paste (fig. 4) subjected to the anti-settling treatment are dispersed more uniformly.
Experimental example 4: conductivity test
Taking two groups of conductive silver pastes which are prepared by the method and are not subjected to anti-settling treatment, wherein one group is subjected to anti-settling treatment according to the method and is marked as an SDS + SDBS group, the other group is not subjected to any treatment and is marked as an original group, and conductive silver powder fineness measurement, silver paste particle size measurement, silver paste viscosity measurement and volume resistivity test are respectively carried out on the conductive silver pastes on two sides, and the results are shown in Table 1, wherein the conductive silver powder fineness, the silver paste viscosity and the volume resistivity of the two groups of conductive silver pastes are consistent, but the particle size (3.5 mu m) of the silver paste particles of the SDS + SDBS group is smaller than the particle size (4 mu m) of the silver paste particles of the original group.
TABLE 1
Drawings
FIG. 1 shows RSH values of conductive silver paste before and after anti-settling treatment;
FIG. 2 shows RSH values of conductive silver pastes when SDS + SDBS of different concentrations is added;
FIG. 3 is an SEM image of a conductive silver paste without anti-settling treatment;
fig. 4 is an SEM image of the conductive silver paste processed by the present invention.
Detailed Description
The embodiment of the invention comprises the following steps:
example 1: the conductive silver paste with good anti-settling effect comprises the following components in parts by weight: 80 parts of flake silver powder, 558 parts of A-type epoxy resin E, 2 parts of phthalic anhydride, 0.5 part of tetraethyl titanate, 0.3 part of sodium dodecyl sulfate and 0.1 part of sodium dodecyl benzene sulfonate.
The preparation method of the conductive silver paste with good anti-settling effect comprises the following steps:
(1) preparing flake silver powder: first AgNO3Prepared into an aqueous solution to AgNO3Adding AgNO into aqueous solution3Cetyl trimethyl ammonium bromide in an amount of 0.1% of the total amount of the aqueous solution, and then the aqueous ascorbic acid solution was heated to 50 ℃ and adjustedpH 13, adding AgNO with cetyl trimethyl ammonium bromide3Mixing the aqueous solution and the ascorbic acid aqueous solution for reaction, filtering, washing with deionized water, washing with absolute ethyl alcohol, and drying to obtain the flaky silver powder with the average diameter of 2-5 microns;
(2) preparing conductive slurry: heating the A-type epoxy resin E55 to 85 ℃, then directly adding the flake silver powder prepared in the step (1) into the heated A-type epoxy resin E55, uniformly stirring, then adding phthalic anhydride and tetraethyl titanate, and uniformly stirring to form conductive slurry;
(3) anti-settling treatment: and (3) adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate into the silver paste prepared in the step (2), and stirring and pre-dissolving to obtain the conductive silver paste with good anti-settling effect.
Example 2: the conductive silver paste with good anti-settling effect comprises the following components in parts by weight: 85 parts of flake silver powder, 10 parts of epoxy resin, 3 parts of phthalic anhydride, 1 part of tetraethyl titanate, 0.8 part of sodium dodecyl sulfate and 0.5 part of sodium dodecyl benzene sulfonate.
The preparation method of the conductive silver paste with good anti-settling effect comprises the following steps:
(1) preparing flake silver powder: first AgNO3Prepared into an aqueous solution to AgNO3Adding AgNO into aqueous solution3Cetyl trimethyl ammonium bromide 0.1% of the total amount of the aqueous solution, then ascorbic acid aqueous solution is heated to 50 ℃ and pH is adjusted to 13, and AgNO with cetyl trimethyl ammonium bromide added thereto3Mixing the aqueous solution and the ascorbic acid aqueous solution for reaction, filtering, washing with deionized water, washing with absolute ethyl alcohol, and drying to obtain the flaky silver powder with the average diameter of 2-5 microns;
(2) preparing conductive slurry: heating the A-type epoxy resin E55 to 90 ℃, directly adding the flake silver powder prepared in the step (1) into the heated A-type epoxy resin E55, uniformly stirring and ultrasonically oscillating, then adding phthalic anhydride and tetraethyl titanate, uniformly stirring, and ultrasonically oscillating during stirring to form conductive slurry;
(3) anti-settling treatment: and (3) adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate into the silver paste prepared in the step (2), and stirring and pre-dissolving to obtain the conductive silver paste with good anti-settling effect.
Example 3: the conductive silver paste with good anti-settling effect comprises the following components in parts by weight: 75 parts of flake silver powder, 516 parts of A-type epoxy resin, 1 part of phthalic anhydride, 0.2 part of sodium dodecyl sulfate and 0.05 part of sodium dodecyl benzene sulfonate.
The preparation method of the conductive silver paste with good anti-settling effect comprises the following steps:
(1) preparing flake silver powder: first AgNO3Prepared into an aqueous solution to AgNO3Adding AgNO into aqueous solution3Cetyl trimethyl ammonium bromide 0.1% of the total amount of the aqueous solution, then ascorbic acid aqueous solution is heated to 50 ℃ and pH is adjusted to 13, and AgNO with cetyl trimethyl ammonium bromide added thereto3Mixing the aqueous solution and the ascorbic acid aqueous solution for reaction, filtering, washing with deionized water, washing with absolute ethyl alcohol, and drying to obtain the flaky silver powder with the average diameter of 2-5 microns;
(2) preparing conductive slurry: heating the A-type epoxy resin E51 to 80 ℃, then directly adding the flake silver powder prepared in the step (1) into the heated A-type epoxy resin E51, uniformly stirring, then adding phthalic anhydride and tetraethyl titanate, and uniformly stirring to form conductive slurry;
(3) anti-settling treatment: and (3) adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate into the silver paste prepared in the step (2), and stirring and pre-dissolving to obtain the conductive silver paste with good anti-settling effect.
Claims (7)
1. The utility model provides an prevent subsiding effectual electrically conductive silver thick liquid which characterized in that, by weight, including: 80 parts of flake silver powder, 8 parts of epoxy resin, 2 parts of phthalic anhydride, 0.5 part of tetraethyl titanate, 0.3 part of sodium dodecyl sulfate and 0.1 part of sodium dodecyl benzene sulfonate;
the conductive silver paste is prepared by the following method:
(1) preparing flake silver powder: first AgNO3Prepared into an aqueous solution to AgNO3Adding surfactant into the aqueous solution, heating the reducing agent solution to 50 deg.C and adjusting pH to 13, and adding surfactant AgNO3Mixing the aqueous solution and the reducing agent solution for reaction, filtering, washing with deionized water, washing with absolute ethyl alcohol, and drying to obtain the flake silver powder;
(2) preparing conductive slurry: heating the epoxy resin to 80-90 ℃, then directly adding the flake silver powder prepared in the step (1) into the heated epoxy resin, uniformly stirring, then adding phthalic anhydride and tetraethyl titanate, and uniformly stirring to form conductive slurry;
(3) anti-settling treatment: and (3) adding sodium dodecyl sulfate and sodium dodecyl benzene sulfonate into the silver paste prepared in the step (2), and stirring and pre-dissolving to obtain the conductive silver paste with good anti-settling effect.
2. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: the epoxy resin is bisphenol A type epoxy resin E55 or E51.
3. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: in the step (1), the surfactant is cetyl trimethyl ammonium bromide, and the addition amount of the surfactant is 0.1% of the total amount.
4. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: in the step (1), the reducing agent solution is ascorbic acid aqueous solution.
5. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: in the step (2), the heating temperature of the epoxy resin is 85 ℃.
6. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: in the step (2) and the step (3), ultrasonic dispersion treatment is adopted during stirring and mixing.
7. The conductive silver paste with good anti-settling effect of claim 1, wherein the conductive silver paste is characterized in that: the average diameter of the flake silver powder prepared in the step (1) is 2-5 microns.
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| CN106601334A (en) * | 2016-12-29 | 2017-04-26 | 广州凯耀资产管理有限公司 | Electronic paste for touch screens and preparation method thereof |
| CN107393626A (en) * | 2017-06-27 | 2017-11-24 | 西安工程大学 | A kind of hot method powdery electric slurry and preparation method thereof |
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| CN101950595A (en) * | 2010-09-27 | 2011-01-19 | 彩虹集团公司 | Low-temperature cured conductive paste with ultra-low silver content and preparation method thereof |
| JP2012193454A (en) * | 2012-05-25 | 2012-10-11 | Dowa Holdings Co Ltd | Silver powder, and method of producing the same |
| CN103000253A (en) * | 2012-11-10 | 2013-03-27 | 江苏瑞德新能源科技有限公司 | Latent-curing conductive paste and method of forming electrode on substrate thereby |
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| CN104464887B (en) * | 2014-11-17 | 2016-09-14 | 苏州斯迪克新材料科技股份有限公司 | A kind of nano-silver thread conductive silver paste and preparation method thereof |
| CN104959625B (en) * | 2015-06-24 | 2017-06-09 | 广东风华高新科技股份有限公司 | The preparation method of flake silver powder |
| CN104962226B (en) * | 2015-08-06 | 2017-03-01 | 中国振华集团云科电子有限公司 | A kind of conductive silver glue and its preparation method and application |
| CN105271175B (en) * | 2015-11-16 | 2017-10-24 | 中南大学 | A kind of process for dispersing of CNT |
| CN105386091A (en) * | 2015-12-24 | 2016-03-09 | 南昌航空大学 | Graphite dispersion composite additive |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010137080A1 (en) * | 2009-05-27 | 2010-12-02 | Ｄｏｗａエレクトロニクス株式会社 | Process for producing metallic nanoparticle with low-temperature sinterability, metallic nanoparticle, and process for producing dispersion containing the same |
| CN101950595A (en) * | 2010-09-27 | 2011-01-19 | 彩虹集团公司 | Low-temperature cured conductive paste with ultra-low silver content and preparation method thereof |
| JP2012193454A (en) * | 2012-05-25 | 2012-10-11 | Dowa Holdings Co Ltd | Silver powder, and method of producing the same |
| CN103000253A (en) * | 2012-11-10 | 2013-03-27 | 江苏瑞德新能源科技有限公司 | Latent-curing conductive paste and method of forming electrode on substrate thereby |
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