阅读说明：本技术 基于化学镀镍和电镀锡的管式瓷介电容电极制作方法 (Method for manufacturing tubular ceramic dielectric capacitor electrode based on chemical nickel plating and electrolytic tinning ) 是由 杨洪霞 彭其林 陈香 于 2020-03-11 设计创作，主要内容包括：本发明公开了一种基于化学镀镍和电镀锡的管式瓷介电容电极制作方法,包括以下步骤：对挤制或干压成型后烧制的瓷管进行粗化；高温活化；次亚磷酸钠溶液活化；化学预镀镍；第一次盐酸活化；化学镀镍；第二次盐酸活化；加厚镀镍；电镀锡处理；磨掉两端端头,露出瓷基体；检查和电性能测试,完成管式瓷介电容电极的制作。本发明采用特定工艺流程制作管式瓷介电容的电极,得到的产品完全满足耐电压、绝缘电阻、电容量、介质损耗角正切、可焊性和结合力等性能参数需求,产品质量高、寿命长,而且因为不用手工涂银而提高了生产效率,节约了生产成本；本发明尤其适合C型管式瓷介电容电极的制作。(The invention discloses a method for manufacturing a tubular ceramic dielectric capacitor electrode based on chemical nickel plating and electrolytic tinning, which comprises the following steps: coarsening the ceramic tube which is formed by extrusion or dry pressing and then fired; high-temperature activation; activating a sodium hypophosphite solution; chemical nickel preplating; first hydrochloric acid activation; chemical nickel plating; second hydrochloric acid activation; thickening and nickel plating; carrying out electrotinning treatment; grinding off end heads at two ends to expose the ceramic substrate; and (5) inspecting and testing the electrical property to finish the manufacture of the tubular ceramic dielectric capacitor electrode. The invention adopts a specific process flow to manufacture the electrode of the tubular ceramic dielectric capacitor, the obtained product completely meets the requirements of performance parameters such as voltage resistance, insulation resistance, capacitance, dielectric loss tangent, weldability, binding force and the like, the product has high quality and long service life, and the production efficiency is improved and the production cost is saved because the manual silver coating is not needed; the invention is especially suitable for manufacturing C-shaped tubular ceramic dielectric capacitor electrodes.)

1. A method for manufacturing a tubular ceramic dielectric capacitor electrode based on chemical nickel plating and electrolytic tinning is characterized by comprising the following steps: the method comprises the following steps:

step 1, roughening the extruded or dry-pressed fired ceramic tube;

step 2, performing high-temperature activation on the roughened ceramic tube;

step 3, activating the porcelain tube activated at high temperature by using a sodium hypophosphite solution;

step 4, carrying out chemical nickel preplating on the ceramic tube activated by the sodium hypophosphite solution;

step 5, carrying out first hydrochloric acid activation on the ceramic tube after the chemical nickel pre-plating;

step 6, carrying out chemical nickel plating on the ceramic tube after the first hydrochloric acid activation;

step 7, carrying out secondary hydrochloric acid activation on the ceramic tube after the chemical nickel plating;

step 8, thickening and nickel plating are carried out on the porcelain tube after the second hydrochloric acid activation;

step 9, carrying out electrotinning treatment on the thickened nickel-plated ceramic tube;

step 10, grinding the end heads at the two ends of the porcelain tube after electrotinning treatment to reach the required ranges of capacity and product size, exposing a porcelain substrate, and then cleaning and drying;

and 11, inspecting and testing the electrical property of the ceramic tube with the end ground off to finish the manufacture of the tubular ceramic dielectric capacitor electrode.

2. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the method comprises the following steps: the specific method of the step 1 is as follows: soaking the extruded or dry-pressed and fired ceramic tube into hydrofluoric acid with concentration of 5-10% for 10-15 min, stirring and turning over for soaking to coarsen the inner and outer surfaces of the ceramic tube uniformly, taking out the ceramic tube, washing with water, dehydrating with alcohol, and drying to finish coarsening.

3. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the method comprises the following steps: the specific method of the step 2 is as follows: immersing the roughened porcelain tube into the palladium slurry, stirring and overturning for immersion for 1-5 min to uniformly immerse the inner surface and the outer surface of the porcelain tube with the palladium slurry, then putting the porcelain tube into an oven at the temperature of (80-120) DEG for drying, then putting the porcelain tube after drying into a muffle furnace at the temperature of (600-700) DEG for firing for 10-30 min, and taking out to complete high-temperature activation; the palladium slurry comprises the following components in parts by weight: 2-10% of ethyl cellulose, 30-45% of terpineol, 20-40% of ethylene glycol ethyl ether, 0.2-1% of mixed oleic acid, 1-2% of palladium chloride, 5-20% of hydrochloric acid solution and 5-20% of polyethylene glycol in a volume ratio of 1: 1; the preparation method of the palladium slurry comprises the following steps: weighing ethyl cellulose and terpineol, preserving the temperature at 30-40 ℃ for about (6-10) h, dissolving, adding ethylene glycol ethyl ether and mixed oleic acid, and grinding in a ball mill for more than 40h to prepare ethyl cellulose mixed solution; and then adding a palladium chloride solution and polyethylene glycol which are dissolved by hydrochloric acid in a volume ratio of 1:1 into the mixed solution, and continuously performing ball milling in a ball mill for more than 48 hours to prepare palladium slurry.

4. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the specific method in the step 3 is to immerse the ceramic tube after the high-temperature activation into a sodium hypophosphite solution with the concentration of (10-40) g/L, stir and stir for 3-5 min, and then take out the ceramic tube to complete the activation of the sodium hypophosphite solution.

5. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the specific method in the step 4 is that the ceramic tube activated by the sodium hypophosphite solution is immersed in the chemical nickel pre-plating solution at the temperature of 50-70 ℃ for 5-10 min, then the ceramic tube is taken out for washing, and the ceramic tube is taken out after washing to finish the chemical nickel pre-plating, wherein the chemical nickel pre-plating solution takes water as a solvent and comprises the following raw materials of nickel sulfate (10-30) g/L and sodium hypophosphite (10-30) g/L.

6. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the method comprises the following steps: the specific method of the step 5 is as follows: and (3) putting the ceramic tube subjected to chemical nickel preplating into a hydrochloric acid solution with the concentration of 5-15% for activation for less than 5min, taking out and washing with water, and taking out after washing with water to finish the first hydrochloric acid activation.

7. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the specific method in the step 6 is that the ceramic tube after the first hydrochloric acid activation is immersed in an electroless nickel plating solution at the temperature of 80-90 ℃ for not less than 30min, then the ceramic tube is taken out for washing, and the ceramic tube is taken out after washing to finish the electroless nickel plating, wherein the electroless nickel plating solution takes water as a solvent, and comprises the following raw materials in percentage by weight, namely (30-50) g/L of nickel sulfate, (10-30) g/L of sodium hypophosphite and (8-15) g/L of sodium acetate.

8. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the electroless nickel plating and the electrolytic tin plating according to claim 1, wherein the method comprises the following steps: the specific method of the step 7 is as follows: and (3) activating the ceramic tube after the chemical nickel plating in a hydrochloric acid solution with the concentration of 5-15% for less than 3min, then taking out and washing with water, and taking out after washing with water to finish the second hydrochloric acid activation.

9. The method for manufacturing the tubular ceramic dielectric capacitor electrode based on the chemical nickel plating and the electrolytic tin plating according to claim 1, wherein the specific method in the step 8 is that the ceramic tube after the second hydrochloric acid activation is immersed in a thickened nickel plating solution at the temperature of 80-90 ℃, the immersion time and the chemical nickel plating time are not less than 2 hours, then the ceramic tube is taken out and washed with water, and the thickened nickel plating solution is taken out after washing with water to finish the thickened nickel plating, wherein the thickened nickel plating solution takes water as a solvent and comprises the following raw materials in percentage by weight, namely 30-40 g/L of nickel sulfate, 10-30 g/L of sodium hypophosphite and 8-15 g/L of trisodium citrate.

10. The method for manufacturing a tubular ceramic dielectric capacitor electrode based on electroless nickel plating and electrolytic tin plating according to claim 1, wherein the specific method of the step 9 is to firstly activate the ceramic tube after thickening nickel plating with methanesulfonic acid with the concentration of (100-150) g/L, and then carry out matte electroplating with pure tin, namely, the ceramic tube after methanesulfonic acid activation is electroplated in a plating solution under the condition that the current density is (0.2-0.5) A/dm²And taking out the electroplated tin after electroplating at room temperature to finish the electrotinning treatment, wherein the plating solution comprises the following raw materials of stannous methanesulfonate (10-20) g/L, methanesulfonic acid (100-150) g/L and an additive (15-20) ml/L.

Technical Field

The invention relates to a method for manufacturing a tubular ceramic dielectric capacitor electrode made of titanate series ceramics, in particular to a method for manufacturing a tubular ceramic dielectric capacitor electrode based on chemical nickel plating and electrolytic tinning.

Background

The ceramic dielectric capacitor is a capacitor with ceramic as a dielectric material and can be divided into a low-frequency ceramic dielectric capacitor and a high-frequency ceramic dielectric capacitor according to different ceramic materials; the structure types of the capacitor are classified into a wafer capacitor, a tubular capacitor, a rectangular capacitor, a feedthrough capacitor and the like, and the preparation of the terminal electrode usually adopts a process method of coating silver paste and then sintering.

The electrode of the traditional tubular ceramic dielectric capacitor is mostly manufactured by a process of manually coating silver (or palladium silver) and then sintering, and in order to meet the product performance requirement, three times of silver coating and three times of sintering are generally needed. The process has the following defects: a large amount of noble metal silver or palladium is needed, and the process time for preparing a batch of products is long; the capacity of the same product is closely related to the coated area, so that the uniformity of the capacity of the coated product is greatly different due to human factors; in addition, the coating operation is more difficult for short and small porcelain tubes.

At present, another electrode manufacturing process is to use chemical plating method for ceramic material. Electroless plating is a method of obtaining a metal coating on a plating member having a catalytic surface by oxidation-reduction reaction without applying electricity, and electroless nickel plating is a method of depositing nickel ions in a solution on a surface having catalytic activity by reduction with a reducing agent. The chemical plating can be carried out on the metal surface through special coarsening, sensitization and activation chemical treatment, the chemical plating layer has uniform thickness, and the plating solution is stable and easy to control.

At present, aiming at aluminum oxide series ceramics, an electrode is manufactured by nickel plating through a process of 'coarsening-sensitization-activation-chemical nickel plating-heat treatment', but for barium titanate series tubular ceramic dielectric capacitors, the electrode is difficult to manufacture through the process, and because the nickel layer has poorer weldability than tin and short storage time, electrotinning is needed to be performed on the nickel layer so as to meet the requirements of product weldability and long-time storage.

In addition, the tubular ceramic capacitor electrode is manufactured by adopting a process of silver-coated priming-chemical nickel plating-electrolytic tin plating, but the manufacturing process is long and uneconomical.

Disclosure of Invention

The invention aims to solve the problems and provide a method for manufacturing a tubular ceramic capacitor electrode based on chemical nickel plating and electrolytic tin plating.

The invention realizes the purpose through the following technical scheme:

a method for manufacturing a tubular ceramic dielectric capacitor electrode based on chemical nickel plating and electrolytic tinning comprises the following steps:

step 1, roughening the extruded or dry-pressed fired ceramic tube;

step 2, performing high-temperature activation on the roughened ceramic tube;

step 3, activating the porcelain tube activated at high temperature by using a sodium hypophosphite solution;

step 4, carrying out chemical nickel preplating on the ceramic tube activated by the sodium hypophosphite solution;

step 5, carrying out first hydrochloric acid activation on the ceramic tube after the chemical nickel pre-plating;

step 6, carrying out chemical nickel plating on the ceramic tube after the first hydrochloric acid activation;

step 7, carrying out secondary hydrochloric acid activation on the ceramic tube after the chemical nickel plating;

step 8, thickening and nickel plating are carried out on the porcelain tube after the second hydrochloric acid activation;

step 9, carrying out electrotinning treatment on the thickened nickel-plated ceramic tube;

step 10, grinding the end heads at the two ends of the porcelain tube after electrotinning treatment to reach the required ranges of capacity and product size, exposing a porcelain substrate, and then cleaning and drying;

and 11, inspecting and testing the electrical property of the ceramic tube with the end ground off to finish the manufacture of the tubular ceramic dielectric capacitor electrode.

Preferably, the specific method of step 1 is as follows: soaking the extruded or dry-pressed and fired ceramic tube into hydrofluoric acid with concentration of 5-10% for 10-15 min, stirring and turning over for soaking to coarsen the inner and outer surfaces of the ceramic tube uniformly, taking out the ceramic tube, washing with water, dehydrating with alcohol, and drying to finish coarsening.

Preferably, the specific method of step 2 is: immersing the roughened porcelain tube into the palladium slurry, stirring and overturning for immersion for 1-5 min to uniformly immerse the inner surface and the outer surface of the porcelain tube with the palladium slurry, then putting the porcelain tube into an oven at the temperature of (80-120) DEG for drying, then putting the porcelain tube after drying into a muffle furnace at the temperature of (600-700) DEG for firing for 10-30 min, and taking out to complete high-temperature activation; the palladium slurry comprises the following components in parts by weight: 2-10% of ethyl cellulose, 30-45% of terpineol, 20-40% of ethylene glycol ethyl ether, 0.2-1% of mixed oleic acid, 1-2% of palladium chloride, 5-20% of hydrochloric acid solution and 5-20% of polyethylene glycol in a volume ratio of 1: 1; the preparation method of the palladium slurry comprises the following steps: weighing ethyl cellulose and terpineol, preserving the temperature at 30-40 ℃ for about (6-10) h, dissolving, adding ethylene glycol ethyl ether and mixed oleic acid, and grinding in a ball mill for more than 40h to prepare ethyl cellulose mixed solution; and then adding a palladium chloride solution and polyethylene glycol which are dissolved by hydrochloric acid in a volume ratio of 1:1 into the mixed solution, and continuously performing ball milling in a ball mill for more than 48 hours to prepare palladium slurry.

Preferably, the specific method of the step 3 is that the porcelain tube activated at high temperature is immersed into a sodium hypophosphite solution with the concentration of (10-40) g/L, stirred and immersed for 3-5 min, and then taken out, so that the activation of the sodium hypophosphite solution is completed.

Preferably, the specific method in the step 4 is that the porcelain tube activated by the sodium hypophosphite solution is immersed into the chemical nickel preplating solution with the temperature of 50-70 ℃ for 5-10 min, then the porcelain tube is taken out for washing, and the porcelain tube is taken out after washing to finish the chemical nickel preplating, wherein the chemical nickel preplating solution takes water as a solvent and comprises the following raw materials of (10-30) g/L of nickel sulfate and (10-30) g/L of sodium hypophosphite.

Preferably, the specific method of step 5 is: and (3) putting the ceramic tube subjected to chemical nickel preplating into a hydrochloric acid solution with the concentration of 5-15% for activation for less than 5min, taking out and washing with water, and taking out after washing with water to finish the first hydrochloric acid activation.

Preferably, the specific method of the step 6 is that the porcelain tube activated by the hydrochloric acid for the first time is immersed in a chemical nickel plating solution at the temperature of 80-90 ℃, the immersion time is not less than 30min, then the porcelain tube is taken out and washed by water, and the porcelain tube is taken out after being washed by water to complete the chemical nickel plating, wherein the chemical nickel plating solution takes water as a solvent, takes water as a solvent and comprises the following raw materials in percentage by weight, namely (30-50) g/L of nickel sulfate, 10-30) g/L of sodium hypophosphite and (8-15) g/L of sodium acetate.

Preferably, the specific method of step 7 is as follows: and (3) activating the ceramic tube after the chemical nickel plating in a hydrochloric acid solution with the concentration of 5-15% for less than 3min, then taking out and washing with water, and taking out after washing with water to finish the second hydrochloric acid activation.

Preferably, the specific method of the step 8 is that the porcelain tube after the second hydrochloric acid activation is immersed into a thickening nickel plating solution at the temperature of (80-90) DEG C, the thickening nickel plating solution is overturned and immersed for a certain time, the overturning and immersion time and the chemical nickel plating time are not less than 2 hours, then the porcelain tube is taken out and washed with water, and the thickening nickel plating solution is taken out after washing with water and is finished, wherein the thickening nickel plating solution takes water as a solvent and comprises the following raw materials in percentage by weight, namely (30-40) g/L of nickel sulfate, (10-30) g/L of sodium hypophosphite and (8-15) g/L of trisodium citrate.

Preferably, the specific method of the step 9 comprises the steps of firstly activating the ceramic tube after thickening nickel plating by methanesulfonic acid with the concentration of (100-150) g/L, and then carrying out matte electroplating of pure tin, namely placing the ceramic tube after activating the methanesulfonic acid in a plating solution for electroplating under the condition that the current density is (0.2-0.5) A/dm²And taking out the electroplated tin after electroplating at room temperature to finish the electrotinning treatment, wherein the plating solution comprises the following raw materials of stannous methanesulfonate (10-20) g/L, methanesulfonic acid (100-150) g/L and an additive (15-20) ml/L.

The invention has the beneficial effects that:

the invention adopts the technological process of 'coarsening-high temperature activation-sodium hypophosphite solution activation-chemical preplating nickel-first hydrochloric acid activation-chemical plating nickel-second hydrochloric acid activation-thickening nickel plating-electrotinning treatment-end grinding-performance test' to manufacture the electrode of the tubular ceramic dielectric capacitor, and the subsequent chemical plating nickel layer and the ceramic tube have good bonding force by performing high temperature activation on the ceramic tube, thereby ensuring that the performance parameter test results of voltage resistance, insulation resistance, capacitance, dielectric loss tangent and the like reach the product requirements; because the weldability of the nickel-plated layer can be rapidly reduced along with the prolonging of the storage time, and if the welding performance of the porcelain tube is poor, the performance (voltage resistance, insulation resistance, capacitance, dielectric loss tangent, binding force and the like) of the product after welding and assembling can be seriously influenced, the invention electroplates tin on the nickel layer, so that the product has good weldability, and simultaneously meets the requirements of the product on the storage life and other performance parameters; in addition, because the silver is not coated by hands, the production efficiency is improved, and the production cost is saved; the invention is especially suitable for manufacturing C-shaped tubular ceramic dielectric capacitor electrodes.

Detailed Description

The invention is further illustrated by the following examples: