MLCC surface treatment system and process

Abstract

The present invention discloses an MLCC surface treatment system, which comprises an activation tank, a first rinsing tank, a low-concentration nickel tank, a nickel plating tank, a nickel recovery tank, a second rinsing tank, a low-concentration tin tank, a tin plating tank, a tin recovery tank, a third rinsing tank, a neutralization tank, a fourth rinsing tank and a boiling tank arranged in sequence along the production process direction; nickel solution is provided in the nickel plating tank and the low-concentration nickel tank, the concentration of the nickel solution in the low-concentration nickel tank is lower than the concentration of the nickel solution in the nickel plating tank, and the low-concentration nickel tank is connected to the nickel recovery tank through a first pipeline; tin solution is provided in the tin plating tank and the low-concentration tin tank, the concentration of the tin solution in the low-concentration tin tank is lower than the concentration of the tin solution in the tin plating tank, and the low-concentration tin tank is connected to the tin recovery tank through a second pipeline. The present invention discloses an MLCC surface treatment process. The present invention can improve the concentration stability of the electroplating solution in the deposition process, reduce the consumption of the solution, thereby ensuring the quality and solderability of the product coating.

Description

Technical Field

[0001] The present invention relates to the technical field of MLCC (multilayer chip ceramic capacitor) production, and in particular to a MLCC surface treatment process. Background Art

[0002] The structure of multilayer ceramic capacitor (MLCC) mainly consists of three parts: ceramic body, inner electrode and outer electrode. The outer electrode is composed of copper layer, nickel layer and tin layer in sequence. The nickel layer and tin layer in the outer electrode are completed in the deposition process, that is, through the roller plating machine, the multilayer ceramic capacitor is placed in a nickel and tin solution tank with a certain concentration, and the nickel and tin layers are plated on the surface of the copper layer that has been sealed. The stability of the nickel and tin solution concentration and daily maintenance play a key role in the quality of the outer electrode plating of ceramic capacitor products.

[0003] The traditional surface treatment process of the deposition process is: after the product, i.e. the multilayer ceramic capacitor, starts to be loaded, it goes through activation, rinsing, nickel plating, nickel solution recovery, rinsing, tin plating, tin solution recovery, and then rinses, neutralizes, rinses and boils to end the process.

[0004] The key steps of the whole process are nickel plating and tin plating. The principle is that in a certain concentration of nickel or tin solution, the rolling screen loaded with multilayer ceramic capacitor products and stainless steel beads rotates inside the tank. The stainless steel beads are in full contact with the multilayer ceramic capacitors during the continuous rolling of the rolling screen. The steel balls play a conductive role, and under the action of direct current, an oxidation-reduction reaction occurs on the surface of the product. The nickel or tin anode loses electrons to form metal cations. The free metal cations gain electrons at the cathode, that is, the surface of the product and are reduced, that is, a nickel or tin metal layer is deposited on the surface of the product end. During the electroplating process, the current required to be applied varies depending on the specifications and weight of the multilayer ceramic capacitors to be plated. Generally, the current for nickel plating is 30-75 amperes, the current for tin plating is 20-45 amperes, and the time for nickel or tin electroplating is generally 60-150 minutes. The time for the rolling screen in other tanks is: activation 1 minute, rinsing 2-3 minutes, recycling 2-3 minutes, neutralization 1 minute, and boiling 5-10 minutes.

[0005] In the process of production control, in order to obtain a metal coating with dense crystals, good quality and uniform coating thickness, the concentration of nickel and tin metal ions in the plating tank must be controlled within the range required by the process. Therefore, how to stabilize the concentration of the solution is crucial. However, when the surface treatment production line is in the production process, there are continuous roller screens entering and exiting the nickel and tin solution tanks, and the concentration of the solution is constantly consumed. In addition to the chemical reaction in the tank causing the concentration of the solution to decrease, another important factor is that the solution is constantly taken out by the roller screen, especially during the full-load production of the production line, there will be continuous rinsing water from the rinse tank brought into the solution tank, and there will be solution taken out by the roller screen, resulting in a rapid decrease in the concentration of nickel and tin ions in the solution. If the solution is not replenished in time, or the employee does not scoop the solution from the recovery tank back to the main tank in time, it will affect the electroplating efficiency of the product, and the thickness after plating will not meet the process standards, thus causing product quality risks. Summary of the invention

[0006] The purpose of the present invention is to provide an MLCC surface treatment system and process, which can improve the concentration stability of electroplating solution in the deposition process, reduce solution consumption, thereby ensuring the quality and solderability of the product coating, and at the same time reduce the frequency of manual recovery of nickel and tin solutions.

[0007] In order to achieve the above object, the technical solution adopted in one aspect of the present invention is:

[0008] An MLCC surface treatment system, comprising an activation tank, a first rinsing tank, a low-concentration nickel tank, a nickel plating tank, a nickel recovery tank, a second rinsing tank, a low-concentration tin tank, a tin plating tank, a tin recovery tank, a third rinsing tank, a neutralization tank, a fourth rinsing tank and a water boiling tank, which are sequentially arranged along the production process direction;

[0009] The nickel plating tank and the low-concentration nickel tank are both provided with nickel solution, the concentration of the nickel solution in the low-concentration nickel tank is lower than the concentration of the nickel solution in the nickel plating tank, and the low-concentration nickel tank is connected to the nickel recovery tank through a first pipeline;

[0010] The tin plating tank and the low-concentration tin tank are both provided with tin solution, the concentration of the tin solution in the low-concentration tin tank is lower than the concentration of the tin solution in the tin plating tank, and the low-concentration tin tank is connected to the tin recovery tank through a second pipeline.

[0011] As a preferred solution of the above-mentioned MLCC surface treatment system, at least two of the first rinsing tank, the second rinsing tank and the third rinsing tank are provided.

[0012] In addition, in order to achieve the above object, another aspect of the present invention adopts the following technical solution:

[0013] An MLCC surface treatment process is applied to the MLCC surface treatment system described in the above items, and the MLCC surface treatment process includes the following steps:

[0014] Step S1: feeding;

[0015] Step S2: activating the MLCC semi-finished product;

[0016] Step S3: rinsing the MLCC semi-finished product after being processed in step S2;

[0017] Step S4: soaking the MLCC semi-finished product after the treatment in step S3 in a low-concentration nickel bath;

[0018] Step S5: performing nickel plating on the MLCC semi-finished product processed in step S4;

[0019] Step S6: Recycling the nickel solution on the MLCC semi-finished product after the treatment in step S5;

[0020] Step S7: rinsing the MLCC semi-finished product after the treatment in step S6;

[0021] Step S8: soaking the MLCC semi-finished product after the treatment in step S7 in a low concentration tin bath;

[0022] Step S9: performing tin plating on the MLCC semi-finished product processed in step S8;

[0023] Step S10: Recycling the tin solution on the MLCC semi-finished product after being processed in step S9;

[0024] Step S11: rinsing the MLCC semi-finished product after being processed in step S10;

[0025] Step S12: neutralizing the MLCC semi-finished product after being processed in step S11;

[0026] Step S13: rinsing the MLCC semi-finished product after the processing in step S12;

[0027] Step S14: boiling the MLCC semi-finished product after the treatment in step S13;

[0028] Step S15: discharging the material.

[0029] As a preferred solution of the above-mentioned MLCC surface treatment process, the rinsing treatments in step S3, step S7 and step S11 are all multi-stage rinsing treatments.

[0030] As a preferred solution of the above-mentioned MLCC surface treatment process, it also includes step S16: regularly sampling and testing the concentration of the nickel solution in the low-concentration nickel tank or the nickel recovery tank, and replenishing the nickel solution in the low-concentration nickel tank or the nickel recovery tank in time.

[0031] As a preferred solution of the above-mentioned MLCC surface treatment process, it also includes step S16: regularly sampling and testing the concentration of the tin solution in the low-concentration tin bath or the tin recovery bath, and replenishing the tin solution in the low-concentration tin bath or the tin recovery bath in time.

[0032] As a preferred solution for the above-mentioned MLCC surface treatment process, the volume of the nickel solution in the low-concentration nickel tank or the nickel recovery tank is 100L, the main salt ion concentration is 60±30g / L, the temperature is 25±5°C, and the pH value is 5.00±0.5; the volume of the nickel solution in the nickel plating tank is 300L, the main salt ion concentration is 80±10g / L, the temperature is 55±3°C, and the pH value is 4.55±0.3.

[0033] As a preferred solution for the above-mentioned MLCC surface treatment process, the volume of the tin solution in the low-concentration tin bath or the tin recovery bath is 100L, the main salt ion concentration is 13±7g / L, the temperature is 25±5°C, and the pH value is 4.00±0.5; the volume of the tin solution in the tin plating bath is 300L, the main salt ion concentration is 15±5g / L, the temperature is 23±3°C, and the pH value is 3.50±0.3.

[0034] The MLCC surface treatment system and process provided by the present invention have the following beneficial effects compared with the prior art:

[0035] On the basis of the existing traditional surface treatment system, the present invention adds a low-concentration nickel tank between the first rinsing tank and the nickel-plating tank, and adds a low-concentration tin tank between the second rinsing tank and the tin-plating tank, so that the low-concentration nickel tank and the low-concentration tin tank can serve as a solution buffer tank, and before the rolling screen loaded with MLCC semi-finished products enters the nickel-plating tank or the tin-plating tank, the MLCC semi-finished products will be first soaked in the low-concentration nickel tank or the low-concentration tin tank, so as to avoid the rolling screen bringing the rinsing water in the rinsing tank directly into the nickel-plating tank or the tin-plating tank, thereby reducing the dilution of the nickel solution in the nickel-plating tank or the tin solution in the tin-plating tank, and when the rolling screen enters the low-concentration nickel tank or the low-concentration tin tank, the nickel solution and the tin solution can be brought to the nickel-plating tank or the tin-plating tank respectively, so that the nickel solution in the nickel-plating tank or the tin solution in the tin-plating tank can be properly At the same time, the low-concentration nickel tank is connected to the nickel recovery tank through the first pipeline, so that the liquid level and concentration of the nickel solution in the low-concentration nickel tank can be equivalent to the liquid level and concentration of the nickel solution in the nickel recovery tank, and a dynamic balance can be achieved; the low-concentration tin tank is connected to the tin recovery tank through the second pipeline, so that the liquid level and concentration of the tin solution in the low-concentration tin tank can be equivalent to the liquid level and concentration of the tin solution in the tin recovery tank, and a dynamic balance can be achieved; in this way, the nickel solution and the tin solution can be reused in a short time, and the concentration of the nickel solution in the nickel plating tank and the concentration of the tin solution in the tin plating tank can be relatively stable for a long time, so as to solve the problem of fast consumption of solution concentration, ensure the quality and solderability of the product coating, and reduce the frequency of manual recovery of nickel and tin solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0037] Figure 1 It is a structural schematic diagram of an MLCC surface treatment system provided by an embodiment of the present invention;

[0038] Figure 2 It is a flow chart of an MLCC surface treatment process provided by an embodiment of the present invention.

[0039] Markings in the figure:

[0040] 1. Activation tank; 2. First rinsing tank; 3. Low-concentration nickel tank; 4. Nickel plating tank; 5. Nickel recovery tank; 6. Second rinsing tank; 7. Low-concentration tin tank; 8. Tin plating tank; 9. Tin recovery tank; 10. Third rinsing tank; 11. Neutralization tank; 12. Fourth rinsing tank; 13. Boiling tank; 14. First pipeline; 15. Second pipeline. DETAILED DESCRIPTION

[0041] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0043] like Figure 1 As shown, one aspect of an embodiment of the present invention provides an MLCC surface treatment system, which includes an activation tank 1, a first rinsing tank 2, a low-concentration nickel tank 3, a nickel plating tank 4, a nickel recovery tank 5, a second rinsing tank 6, a low-concentration tin tank 7, a tin plating tank 8, a tin recovery tank 9, a third rinsing tank 10, a neutralization tank 11, a fourth rinsing tank 12 and a boiling tank 13 arranged in sequence along the production process direction;

[0044] The nickel plating tank 4 and the low-concentration nickel tank 3 are both provided with nickel solution, the concentration of the nickel solution in the low-concentration nickel tank 3 is lower than the concentration of the nickel solution in the nickel plating tank 4, and the low-concentration nickel tank 3 is connected to the nickel recovery tank 5 through a first pipe 14;

[0045] Both the tin plating tank 8 and the low-concentration tin tank 7 are provided with tin solution, the concentration of the tin solution in the low-concentration tin tank 7 is lower than the concentration of the tin solution in the tin plating tank 8 , and the low-concentration tin tank 7 is connected to the tin recovery tank 9 through a second pipe 15 .

[0046] The MLCC surface treatment system of the present embodiment is implemented, on the basis of the existing traditional surface treatment system, a low-concentration nickel tank 3 is added between the first rinsing tank 2 and the nickel-plating tank 4, and a low-concentration tin tank 7 is added between the second rinsing tank 6 and the tin-plating tank 8. As a result, the low-concentration nickel tank 3 and the low-concentration tin tank 7 can act as a solution buffer tank. Before the rolling screen loaded with the MLCC semi-finished products enters the nickel-plating tank 4 or the tin-plating tank 8, the MLCC semi-finished products will be first soaked in the low-concentration nickel tank 3 or the low-concentration tin tank 7 to prevent the rolling screen from directly bringing the rinsing water in the rinsing tank into the nickel-plating tank 4 or the tin-plating tank 8, thereby reducing the dilution of the nickel solution in the nickel-plating tank 4 or the tin solution in the tin-plating tank 8. Moreover, when the rolling screen enters the low-concentration nickel tank 3 or the low-concentration tin tank 7, the nickel solution and the tin solution can be brought to the nickel-plating tank 4 or the tin-plating tank 8, respectively, so that the nickel solution in the nickel-plating tank 4 or the tin-plating tank 8 are diluted. The tin solution in the tin plating tank 8 is properly replenished; at the same time, the low-concentration nickel tank 3 is connected to the nickel recovery tank 5 through the first pipeline 14, which can make the liquid level and concentration of the nickel solution in the low-concentration nickel tank 3 equivalent to the liquid level and concentration of the nickel solution in the nickel recovery tank 5, and achieve dynamic balance; the low-concentration tin tank 7 is connected to the tin recovery tank 9 through the second pipeline 15, which can make the liquid level and concentration of the tin solution in the low-concentration tin tank 7 equivalent to the liquid level and concentration of the tin solution in the tin recovery tank 9, and achieve dynamic balance; in this way, the nickel solution and the tin solution can be reused in a short time, and the concentration of the nickel solution in the nickel plating tank 4 and the concentration of the tin solution in the tin plating tank 8 can be relatively stable for a long time, so as to solve the problem of fast consumption of solution concentration, ensure the quality and solderability of the product coating, and reduce the frequency of manual recovery of nickel and tin solutions.

[0047] Exemplarily, in order to improve the rinsing quality, at least two of the first rinsing tank 2, the second rinsing tank 6 and the third rinsing tank 10 are provided.

[0048] In addition, if Figure 2 As shown, another aspect of the embodiment of the present invention provides an MLCC surface treatment process, which is applied to the MLCC surface treatment system described in the above contents, and the MLCC surface treatment process includes the following steps:

[0049] Step S1: feeding;

[0050] Step S2: activating the MLCC semi-finished product;

[0051] Step S3: rinsing the MLCC semi-finished product after being processed in step S2;

[0052] Step S4: soaking the MLCC semi-finished product after the treatment in step S3 in a low-concentration nickel bath 3;

[0053] Step S5: performing nickel plating on the MLCC semi-finished product processed in step S4;

[0054] Step S6: Recycling the nickel solution on the MLCC semi-finished product after the treatment in step S5;

[0055] Step S7: rinsing the MLCC semi-finished product after the treatment in step S6;

[0056] Step S8: soaking the MLCC semi-finished product after the treatment in step S7 in a low concentration tin bath 7;

[0057] Step S9: performing tin plating on the MLCC semi-finished product processed in step S8;

[0058] Step S10: Recycling the tin solution on the MLCC semi-finished product after being processed in step S9;

[0059] Step S11: rinsing the MLCC semi-finished product after being processed in step S10;

[0060] Step S12: neutralizing the MLCC semi-finished product after being processed in step S11;

[0061] Step S13: rinsing the MLCC semi-finished product after the processing in step S12;

[0062] Step S14: boiling the MLCC semi-finished product after the treatment in step S13;

[0063] Step S15: discharging the material.

[0064] It should be noted that since the MLCC surface treatment process of this embodiment is applied to the MLCC surface treatment system described in the above contents, it has the same technical effects as the MLCC surface treatment system described in the above contents, and will not be repeated here.

[0065] Exemplarily, to improve the rinsing quality, the rinsing processes in step S3, step S7 and step S11 are all multi-stage rinsing processes.

[0066] Exemplarily, the MLCC surface treatment process of this embodiment also includes step S16: regularly sampling and testing the concentration of the nickel solution in the low-concentration nickel tank 3 or the nickel recovery tank 5, and replenishing the nickel solution in the low-concentration nickel tank 3 or the nickel recovery tank 5 in time.

[0067] Exemplarily, the MLCC surface treatment process of this embodiment also includes step S16: regularly sampling and testing the concentration of the tin solution in the low-concentration tin bath 7 or the tin recovery bath 9, and replenishing the tin solution in the low-concentration tin bath 7 or the tin recovery bath 9 in time.

[0068] Exemplarily, in order to improve the crystal density quality, thickness uniformity and weldability of the coating, the volume of the nickel solution in the low-concentration nickel tank or the nickel recovery tank is 100L, the main salt ion concentration is preferably 60±30g / L, the temperature is preferably 25±5°C, and the pH value is preferably 5.00±0.5; the volume of the nickel solution in the nickel plating tank is 300L, the main salt ion concentration is preferably 80±10g / L, the temperature is preferably 55±3°C, and the pH value is preferably 4.55±0.3; the volume of the tin solution in the low-concentration tin tank or the tin recovery tank is 100L, the main salt ion concentration is preferably 13±7g / L, the temperature is preferably 25±5°C, and the pH value is preferably 4.00±0.5; the volume of the tin solution in the tin plating tank is 300L, the main salt ion concentration is preferably 15±5g / L, the temperature is preferably 23±3°C, and the pH value is preferably 3.50±0.3.

[0069] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A MLCC surface treatment system, characterized in that: It includes an activation tank, a first rinsing tank, a low-concentration nickel tank, a nickel plating tank, a nickel recovery tank, a second rinsing tank, a low-concentration tin tank, a tin plating tank, a tin recovery tank, a third rinsing tank, a neutralization tank, a fourth rinsing tank and a water boiling tank which are sequentially arranged along the production process direction; The nickel plating tank and the low-concentration nickel tank are both provided with nickel solution, the concentration of the nickel solution in the low-concentration nickel tank is lower than the concentration of the nickel solution in the nickel plating tank, and the low-concentration nickel tank is connected to the nickel recovery tank through a first pipeline; The tin plating tank and the low-concentration tin tank are both provided with tin solution, the concentration of the tin solution in the low-concentration tin tank is lower than the concentration of the tin solution in the tin plating tank, and the low-concentration tin tank is connected to the tin recovery tank through a second pipeline.

2. The MLCC surface treatment system according to claim 1, characterized in that: There are at least two of the first rinsing tank, the second rinsing tank and the third rinsing tank.

3. A MLCC surface treatment process, characterized in that: Using the MLCC surface treatment system as described in claim 1 or 2, the MLCC surface treatment process comprises the following steps: Step S1: feeding; Step S2: activating the MLCC semi-finished product; Step S3: rinsing the MLCC semi-finished product after being processed in step S2; Step S4: soaking the MLCC semi-finished product after the treatment in step S3 in a low-concentration nickel bath; Step S5: performing nickel plating on the MLCC semi-finished product processed in step S4; Step S6: Recycling the nickel solution on the MLCC semi-finished product after the treatment in step S5; Step S7: rinsing the MLCC semi-finished product after the treatment in step S6; Step S8: soaking the MLCC semi-finished product after the treatment in step S7 in a low concentration tin bath; Step S9: performing tin plating on the MLCC semi-finished product processed in step S8; Step S10: Recycling the tin solution on the MLCC semi-finished product after being processed in step S9; Step S11: rinsing the MLCC semi-finished product after being processed in step S10; Step S12: neutralizing the MLCC semi-finished product after being processed in step S11; Step S13: rinsing the MLCC semi-finished product after the processing in step S12; Step S14: boiling the MLCC semi-finished product after the treatment in step S13; Step S15: discharging the material.

4. The MLCC surface treatment process according to claim 3, characterized in that: The rinsing processes in step S3, step S7 and step S11 are all multi-stage rinsing processes.

5. The MLCC surface treatment process according to claim 3, characterized in that: The method further includes step S16: regularly sampling and testing the concentration of the nickel solution in the low-concentration nickel tank or the nickel recovery tank, and replenishing the nickel solution in the low-concentration nickel tank or the nickel recovery tank in time.

6. The MLCC surface treatment process according to claim 3, characterized in that: The method further comprises step S16: regularly sampling and testing the concentration of the tin solution in the low-concentration tin tank or the tin recovery tank, and replenishing the tin solution in the low-concentration tin tank or the tin recovery tank in time.

7. The MLCC surface treatment process according to claim 3, characterized in that: The volume of the nickel solution in the low-concentration nickel tank or the nickel recovery tank is 100L, the main salt ion concentration is 60±30g / L, the temperature is 25±5°C, and the pH value is 5.00±0.5; the volume of the nickel solution in the nickel plating tank is 300L, the main salt ion concentration is 80±10g / L, the temperature is 55±3°C, and the pH value is 4.55±0.

3.

8. The MLCC surface treatment process according to claim 3, characterized in that: The volume of the tin solution in the low-concentration tin tank or the tin recovery tank is 100L, the main salt ion concentration is 13±7g / L, the temperature is 25±5°C, and the pH value is 4.00±0.5; the volume of the tin solution in the tin plating tank is 300L, the main salt ion concentration is 15±5g / L, the temperature is 23±3°C, and the pH value is 3.50±0.3.

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