Equipment and process for electrochemically supplementing electroplating main ions

Abstract

The invention discloses equipment and a process for electrochemically supplementing electrodeposited tin ions, and relates to the technical field of supplementing metal main ions in electrotinning, the equipment comprises an electrolytic bath and a membrane assembly, the membrane assembly is arranged in the electrolytic bath, and a space between one side of an anionic membrane and an anode plate is arranged as an anode chamber. According to the equipment and the process for electrochemically supplementing the electroplating main ions, the high-acid low-tin solution exceeding the process control upper limit serves as the electrolyte, acid reduction and tin extraction are achieved, so that the tin ion content in the electrolyte is recovered to the preset value, the electrolyte is reused, main ion addition of tin plating application using an insoluble electrode is achieved, and the tin plating efficiency is improved. And the balance of the components of the electroplating liquid is realized, so that the purposes of improving the quality, reducing the operation cost and improving the environmental friendliness of the manufacturing process are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of supplementing metallic tin main ions in electroplating tin, in particular to a device and a process for electrochemically supplementing electroplating main ions. Background Art

[0002] In some electrodeposition applications, such as copper plating of the conductive fence behind the solar panel, or tin plating protection of the circuit board, or tin plating base layer, tin plating is widely needed to protect the copper plating layer. In the traditional soluble electrode electroplating process, metal tin is directly used as the anode, but this process has three problems: First, the dissolution of the soluble anode causes the change of the distance between the cathode and the cathode, and due to the edge effect, the distance between the cathode and the cathode at different positions is inconsistent, which is acceptable in some traditional metal hardware electroplating, but in the processing of precision circuits such as PCB and solar panel metallization and other functional electrodeposition fields, this soluble electrolysis method cannot meet the relevant quality requirements; the second problem is that if a soluble electrode is used, since the anode efficiency is generally higher than the cathode efficiency, the concentration of the main ion in the electrolyte will exceed the quality control range after a period of time, and an insoluble anode is needed to adjust the concentration of the main ion, but this approach will still cause fluctuations in the concentration of the main ion, thereby causing fluctuations in the quality of the electrodeposition; the third problem is that if a soluble anode is used, anode mud will be generated, the anode will be passivated, and periodic maintenance is required, which requires more manpower and poor working conditions. To completely use insoluble electrodes to electroplate tin, it is necessary to replenish the oxygen and metal main ions lost in the electrolyte in a timely manner. For example, in the copper electroplating process, a titanium electrode is used as the anode and copper is deposited at the cathode. Copper oxide is added to the electrolyte to maintain the pH of the electrolyte and the balance of materials. In this way, combined with relevant process control, the electrolyte can be used continuously for more than one year.

[0003] Currently, the supplement of main ions can only be achieved by adding main salts, such as stannous sulfate. However, the addition of main salts leads to an increase in the sulfuric acid content in the electrolyte. When the upper limit of process control is reached, the original electrolyte can only be discarded, resulting in an increase in costs and environmental pressure.

[0004] Therefore, in view of this, the existing structure and defects are studied and improved, and an electrochemical device and process for supplementing the main ions of electroplating are proposed. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an apparatus and process for electrochemically supplementing the main ions of electroplated tin, which solves the problems raised in the above-mentioned background technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: an electrochemical supplementary electroplating main ion device, comprising an electrolytic cell and a membrane assembly, the membrane assembly is arranged inside the electrolytic cell, the membrane assembly comprises an outer frame and an anion membrane, the anion membrane is arranged inside the outer frame, an anode plate and a cathode plate are respectively arranged on both sides of the anion membrane inside the electrolytic cell, the space between one side of the anion membrane and the anode plate is set as an anode chamber, and the space between the other side of the anion membrane and the cathode plate is set as a cathode chamber, and the number of the membrane assembly is at least one.

[0007] Furthermore, a first ion sensor is placed inside the anode chamber, and a second ion sensor is placed inside the cathode chamber.

[0008] Furthermore, two sides of the electrolytic cell are provided with through openings, and the inner opening structural dimensions of the through openings are matched with the outer opening structural dimensions of the outer frame.

[0009] Furthermore, a limiting slide groove is provided at the bottom of the inner wall of the electrolytic cell, and both ends of the limiting slide groove are connected to the penetration opening.

[0010] Furthermore, extension grooves are fixed at the top and bottom ends of the outer sides of the penetration opening, and the extension grooves are connected with the penetration opening and the limiting sliding grooves.

[0011] Furthermore, the cathode plate is a metal tin cathode, and the anode plate is a metal tin anode.

[0012] A method for electrochemically supplementing the main ions of electroplating tin, which uses the above-mentioned device for electrochemically supplementing the main ions of electroplating tin, and the method for electrochemically supplementing the main ions of electroplating tin comprises the following steps:

[0013] Step 1: Use the high-acid, low-tin solution that has reached the industrial control limit on the production line as the electrolyte;

[0014] The reaction on the production line is: 30g / L tin ions; 80g / L sulfuric acid; after electrolysis, the following reaction occurs at the anode:

[0015] 2H2O→O2+4H + +4e -

[0016] The following reactions occur at the cathode:

[0017] 2SnSO4→2Sn+2SO4 2 -4e -

[0018] The overall reaction is as follows:

[0019] 2SnSO4+2H2O=2Sn+O2+H2SO4

[0020] That is, during the electrodeposition process, the stannous ions in the electrolyte decrease, while the acidity increases, and the hydrogen ions replace the stannous ions in the stannous sulfate;

[0021] Step 2: Two electrolytic cells are arranged side by side, and the anion membranes inside the two electrolytic cells are named G and H respectively. G and H divide the chambers inside the two electrolytic cells into four parts, namely A, B, C, and D. The electrolyzed electrolyte E enters the chamber A. Since the anion membrane has very little resistance to the movement of anions, under the promotion of diffusion, the anions in the electrolyte E, namely sulfate, diffuse into the chamber B part, and the hydroxides produced by the decomposition of water in the B part diffuse into the A part, leaving the hydrogen ions to maintain electrical neutrality. After the separation effect of the first part, the acid concentration of the electrolyte E decreases, and the acid concentration of the circulating liquid F in the B part increases;

[0022] A cathode I is inserted into the chamber C. The OH radicals generated on the surface of the cathode I neutralize the hydrogen ions in the circulating liquid F. At the same time, the sulfate radicals in the circulating liquid diffuse to the D part through the H anion membrane under the action of the electric field, and form electrical neutrality with the stannous ions generated by the soluble tin anode in the D part, thereby converting the low-tin and low-acid electrolyte E into a high-tin and low-acid electrolyte K, which can be returned to the electroplating production line for continued use.

[0023] Thus, by design, the composition of the circulating liquid F remains unchanged and circulates between parts B and C; the electrolyte E after electrolysis becomes the plating liquid K that can be returned to the electroplating production line for use.

[0024] Furthermore, the electrochemical method for supplementing stannous ion electroplating also includes the following steps:

[0025] Step 3: Since the anion membrane is easily clogged by impurities in the electrolyte during long-term operation, thereby affecting ion exchange movement, the first ion sensor and the second ion sensor are located on both sides of the anion membrane to detect the ion concentration.

[0026] Furthermore, the method for electrochemically supplementing the main ions of electroplating also includes the following steps:

[0027] Step 4: Based on the change in ion concentration on both sides of the anion membrane, the working state of the anion membrane is determined. If the working state of the anion membrane is lower than the preset value, the first ion sensor and the second ion sensor send an alarm to the staff through the prompter. At this time, the staff takes a new membrane assembly and slides it along the extension groove and pushes the membrane assembly inside the electrolytic cell until the membrane assembly inside the electrolytic cell passes through the penetration port along the limiting slide groove and is discharged from the electrolytic cell, and the new membrane assembly replaces the original membrane assembly position to continue operation.

[0028] The present invention provides an electrochemical device and process for supplementing the main ions of electroplating, which has the following beneficial effects:

[0029] 1. The equipment and process for electrochemically supplementing the main ions of electroplating use a high-acid, low-tin solution that exceeds the upper limit of process control as an electrolyte to achieve acid reduction and tin extraction, thereby restoring the tin ion content in the electrolyte to a preset value, thereby allowing the electrolyte to be reused, achieving the addition of main ions for tin plating applications using insoluble electrodes, and achieving a balance in the composition of the electroplating solution, thereby achieving the purpose of improving quality, reducing operating costs, and improving the environmental friendliness of the process.

[0030] 2. The equipment and process for electrochemical supplementary electroplating of main ions, when the anion membrane needs to be replaced, the new outer frame pushes the old outer frame along the inside of the extension groove, and the two outer frames slide along the inside of the limiting slide groove until the old outer frame is removed, and the new outer frame replaces the ongoing operation, thereby maintaining the operating effect of the anion membrane at all times without stopping the acid reduction and tin extraction operation of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the electrolytic cell of the present invention from the left side perspective;

[0032] Figure 2 It is a schematic structural diagram of the electrolytic cell of the present invention from the right side perspective;

[0033] Figure 3 It is a schematic diagram of the internal structure of the electrolytic cell of the present invention;

[0034] Figure 4 The present invention is a schematic diagram of the specific operation flow of the electrochemical supplementary electroplating main ion.

[0035] In the figure: 1, electrolytic cell; 2, membrane assembly; 201, outer frame; 202, anion membrane; 3, anode plate; 4, cathode plate; 5, anode chamber; 6, cathode chamber; 7, first ion sensor; 8, second ion sensor; 9, penetration opening; 10, limiting slide groove; 11, extension groove. DETAILED DESCRIPTION

[0036] The following embodiments of the present invention are described in further detail 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.

[0037] like Figure 1-Figure 4As shown, the present invention provides a technical solution: an electrochemical supplementary electroplating tin ion device, comprising an electrolytic cell 1 and a membrane assembly 2, the membrane assembly 2 is arranged inside the electrolytic cell 1, the membrane assembly 2 comprises an outer frame 201 and an anion membrane 202, the anion membrane 202 is arranged inside the outer frame 201, an anode plate 3 and a cathode plate 4 are respectively arranged on both sides of the anion membrane 202 inside the electrolytic cell 1, the space between one side of the anion membrane 202 and the anode plate 3 is set as an anode chamber 5, and the space between the other side of the anion membrane 202 and the cathode plate 4 is set as a cathode chamber 6, the number of membrane assemblies 2 is at least one, the cathode plate 4 is a tin cathode, and the anode plate 3 is a tin anode;

[0038] The specific operation is as follows: the high-acid, low-tin solution that has reached the upper limit of industrial control on the production line is used as the electrolyte;

[0039] The reaction on the production line is: 3g / L stannous ions; 80g / L sulfuric acid; after electrolysis, the following reaction occurs at the anode:

[0040] 2H2O→O2+4H + +4e -

[0041] The following reactions occur at the cathode:

[0042] 2SnSO4→2Sn+2SO4 2 -4e -

[0043] The overall reaction is as follows:

[0044] 2SnSO4+2H2O=2Sn+O2+H2SO4

[0045] That is, during the electrodeposition process, the tin ions in the electrolyte decrease, while the acidity increases, and the hydrogen ions replace the stannous ions in the stannous sulfate;

[0046] Two electrolytic cells 1 are arranged side by side, and the anion membranes 202 inside the two electrolytic cells 1 are named G and H respectively. G and H divide the chambers inside the two electrolytic cells 1 into four parts, namely A, B, C, and D. The electrolyte E after electrolysis enters the chamber A. Since the anion membrane 202 has very little resistance to the movement of anions, under the promotion of diffusion, the anions in the electrolyte E, namely sulfate, diffuse into the chamber B part, and the hydroxides produced by the decomposition of water in the B part diffuse into the A part, leaving hydrogen ions to maintain electrical neutrality. After the separation effect of the first part, the acid concentration of the electrolyte E decreases, and the acid concentration of the circulating liquid F in the B part increases.

[0047] A cathode I is inserted into the chamber C. The OH radicals generated on the surface of the cathode I neutralize the hydrogen ions in the circulating liquid F. At the same time, the sulfate radicals in the circulating liquid diffuse to the D part through the H anion membrane 202 under the action of the electric field, and form electrical neutrality with the stannous ions generated by the soluble tin anode in the D part, thereby converting the low-tin and low-acid electrolyte E into a high-tin and low-acid electrolyte K, so that it can be returned to the electroplating production line for continued use.

[0048] Thus, by design, the composition of the circulating liquid F remains unchanged and circulates between parts B and C; the electrolyte E after electrolysis becomes the plating liquid K that can be returned to the electroplating production line for use.

[0049] like Figure 1-Figure 4 As shown, a first ion sensor 7 is placed inside the anode chamber 5, a second ion sensor 8 is placed inside the cathode chamber 6, a through hole 9 is provided on both sides of the electrolytic cell 1, and the inner hole structure size of the through hole 9 is adapted to the outer hole structure size of the outer frame 201, a limiting slide groove 10 is provided at the bottom of the inner wall of the electrolytic cell 1, and the two ends of the limiting slide groove 10 are connected with the through hole 9, and an extension groove 11 is fixed at the top and bottom of the outer side of the through hole 9, and the extension groove 11 is connected with the through hole 9 and the limiting slide groove 10;

[0050] The specific operation is as follows: elastic silica gel is arranged on both sides of the outer frame 201 inside the penetration port 9. Since the anion membrane 202 is easily blocked by impurities in the electrolyte during long-term operation, thereby affecting the ion exchange movement, the first ion sensor 7 and the second ion sensor 8 are located on both sides of the anion membrane 202 to detect the ion concentration. The working state of the anion membrane 202 is determined based on the change in ion concentration on both sides of the anion membrane 202. If the working state of the anion membrane 202 is lower than the preset value, the first ion sensor 7 and the second ion sensor 8 send a prompt to the staff. An alarm is sounded, and at this time, the staff takes a new membrane assembly 2 and makes it slide along the inside of the extension slot 11 and push the membrane assembly 2 inside the electrolytic cell 1 until the membrane assembly 2 inside the electrolytic cell 1 passes through the penetration opening 9 along the inside of the limiting slide slot 10 and is discharged from the electrolytic cell 1, and the new membrane assembly 2 replaces the original membrane assembly 2 to continue working, wherein the elastic silica gel of the new and old membrane assemblies 2 is always attached to the outer frame 201 and both sides of the anion membrane 202 when moving, so as to prevent the membrane assembly 2 from carrying the electrolyte on both sides of the anion membrane 202 inside the electrolytic cell 1 when moving, so as to prevent the electrolyte from leaking;

[0051] Based on the above description, the outer frame 201 in the electrolytic cell 1 of the present invention has an outer opening structure size that is compatible with the inner opening structure size of the penetration opening 9 and the limiting slide groove 10, thereby preventing leakage of the electrolyte. When the anion membrane 202 needs to be replaced, the new outer frame 201 pushes the old outer frame 201 along the inside of the extension groove 11, and the two outer frames 201 slide along the inside of the limiting slide groove 10 until the old outer frame 201 is removed.

[0052] like Figure 1-Figure 4 As shown, a method for electrochemically supplementing the main ions of electroplating is applied with the above-mentioned device for electrochemically supplementing the main ions of electroplating. The method for electrochemically supplementing the main ions of electroplating comprises the following steps:

[0053] Step 1: Use the high-acid, low-tin solution that has reached the industrial control limit on the production line as the electrolyte;

[0054] The reaction on the production line is: 3g / L stannous ions; 80g / L sulfuric acid; after electrolysis, the following reaction occurs at the anode:

[0055] 2H2O→O2+4H + +4e -

[0056] The following reactions occur at the cathode:

[0057] 2SnSO4→2Sn+2SO4 2 -4e -

[0058] The overall reaction is as follows:

[0059] 2SnSO4+2H2O=2Sn+O2+H2SO4

[0060] That is, during the electrodeposition process, the tin ions in the electrolyte decrease, while the acidity increases, and the hydrogen ions replace the stannous ions in the stannous sulfate;

[0061] Step 2: Two electrolytic cells 1 are arranged side by side, and the anion membranes 202 inside the two electrolytic cells 1 are named G and H respectively. G and H divide the chambers inside the two electrolytic cells 1 into four parts, A, B, C, and D. The electrolyte E after electrolysis enters the chamber A. Since the anion membrane 202 has very little resistance to the movement of anions, under the promotion of diffusion, the anions in the electrolyte E, i.e., sulfate, diffuse into the chamber B part, and the hydroxides produced by the decomposition of water in the B part diffuse into the A part, leaving the hydrogen ions to maintain electrical neutrality. After the separation effect of the first part, the acid concentration of the electrolyte E decreases, and the acid concentration of the circulating liquid F in the B part increases;

[0062] A cathode I is inserted into the chamber C. The OH radicals generated on the surface of the cathode I neutralize the hydrogen ions in the circulating liquid F. At the same time, the sulfate radicals in the circulating liquid diffuse to the D part through the H anion membrane 202 under the action of the electric field, and form electrical neutrality with the stannous ions generated by the soluble tin anode in the D part, thereby converting the low-tin and low-acid electrolyte E into a high-tin and low-acid electrolyte K, so that it can be returned to the electroplating production line for continued use.

[0063] Thus, by design, the composition of the circulating liquid F remains unchanged and circulates between the B and C parts; the electrolyte E after electrolysis becomes the plating liquid K that can be returned to the electroplating production line for use;

[0064] Step 3: Since the anion membrane 202 is easily clogged by impurities in the electrolyte during long-term operation, thereby affecting ion exchange movement, the first ion sensor 7 and the second ion sensor 8 are located on both sides of the anion membrane 202 to detect ion concentration;

[0065] Step 4: Based on the change in ion concentration on both sides of the anion membrane 202, the working state of the anion membrane 202 is determined. If the working state of the anion membrane 202 is lower than the preset value, the first ion sensor 7 and the second ion sensor 8 send an alarm to the staff through the prompter. At this time, the staff takes a new membrane assembly 2 and slides it along the extension groove 11 and pushes the membrane assembly 2 inside the electrolytic cell 1 until the membrane assembly 2 inside the electrolytic cell 1 passes through the penetration opening 9 along the limiting slide groove 10 and is discharged from the electrolytic cell 1, and the new membrane assembly 2 replaces the original membrane assembly 2 to continue working.

[0066] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. An electrochemical device for supplementing primary ions in electroplating, comprising an electrolytic cell (1) and a membrane assembly (2), characterized in that: A membrane assembly (2) is arranged inside the electrolytic cell (1), and the membrane assembly (2) comprises an outer frame (201) and an anion membrane (202). The anion membrane (202) is arranged inside the outer frame (201), and an anode plate (3) and a cathode plate (4) are arranged on both sides of the anion membrane (202) inside the electrolytic cell (1), respectively. The space between one side of the anion membrane (202) and the anode plate (3) is set as an anode chamber (5), and the space between the other side of the anion membrane (202) and the cathode plate (4) is set as a cathode chamber (6), and the number of the membrane assembly (2) is at least one.

2. The device for electrochemically supplementing the main ions of electroplating according to claim 1, characterized in that: A first ion sensor (7) is placed inside the anode chamber (5), and a second ion sensor (8) is placed inside the cathode chamber (6).

3. The device for electrochemically supplementing the main ions of electroplating according to claim 1, characterized in that: The electrolytic cell (1) is provided with through openings (9) on both sides, and the inner opening structural dimensions of the through openings (9) are matched with the outer opening structural dimensions of the outer frame (201).

4. The device for electrochemically supplementing the main ions of electroplating according to claim 3, characterized in that: A limiting slide groove (10) is provided at the bottom of the inner wall of the electrolytic cell (1), and both ends of the limiting slide groove (10) are connected to the penetration opening (9).

5. The device for electrochemically supplementing the main ions of electroplating according to claim 4, characterized in that: An extension groove (11) is fixed at the top and bottom ends of the outer side of the penetration opening (9), and the extension groove (11) is connected to the penetration opening (9) and the limiting sliding groove (10).

6. The device for electrochemically supplementing primary ions of electroplating according to claim 1, characterized in that: The cathode plate (4) is a tin cathode, and the anode plate (3) is a tin anode.

7. A method for electrochemically supplementing main ions in electroplating, which uses an electrochemically supplementing main ions in electroplating according to any one of claims 1 to 6, characterized in that: The method for electrochemically supplementing the main ions of electroplating comprises the following steps: Step 1: Use the high-acid, low-tin solution that has reached the industrial control limit on the production line as the electrolyte; The reaction on the production line is: 30g / L stannous ions; 80g / L sulfuric acid; after electrolysis, the following reaction occurs at the anode: 2H2O→O2+4H + +4e - The following reactions occur at the cathode: 2SnSO4→2Sn+2SO4 2 -4e - The overall reaction is as follows: 2SnSO4+2H2O=2Sn+O2+H2SO4 That is, during the electrodeposition process, the stannous ions in the electrolyte decrease, while the acidity increases, and the hydrogen ions replace the stannous ions in the stannous sulfate; Step 2: two electrolytic cells (1) are arranged side by side, and the anion membranes (202) inside the two electrolytic cells (1) are named G and H respectively. G and H divide the chambers inside the two electrolytic cells (1) into four parts, namely A, B, C, and D. The electrolyte E after electrolysis enters the chamber A. Since the anion membrane (202) has very little resistance to the movement of anions, under the influence of diffusion, the anions in the electrolyte E, namely sulfate, diffuse into the chamber B part, and the hydroxyl radicals generated by the decomposition of water in the B part diffuse into the A part, leaving the hydrogen ions to maintain electrical neutrality. After the separation effect of the first part, the acid concentration of the electrolyte E decreases, and the acid concentration of the circulating liquid F in the B part increases. A cathode I is inserted into the chamber C portion, and the OH radicals generated on the surface of the cathode I neutralize the hydrogen ions in the circulating liquid F. At the same time, the sulfate radicals in the circulating liquid diffuse to the D portion through the H anion membrane (202) under the action of the electric field, and form electrical neutrality with the stannous ions generated by the soluble tin anode in the D portion, thereby converting the low-tin and low-acid electrolyte E into a high-tin and low-acid electrolyte K, so that it can be returned to the electroplating production line for continued use; Thus, by design, the composition of the circulating liquid F remains unchanged and circulates between parts B and C; the electrolyte E after electrolysis becomes the plating liquid K that can be returned to the electroplating production line for use.

8. The method for electrochemically supplementing primary ions in electroplating according to claim 7, characterized in that: The method for electrochemically supplementing the main ions of electroplating also includes the following steps: Step 3: Since the anion membrane (202) is easily clogged by impurities in the electrolyte during long-term operation, thereby affecting ion exchange movement, the first ion sensor (7) and the second ion sensor (8) are located on both sides of the anion membrane (202) to detect ion concentration.

9. The method for electrochemically supplementing electrodeposition of tin ions according to claim 8, characterized in that: The method for electrochemically supplementing electroplated tin ions also includes the following steps: Step 4: Based on the change in ion concentration on both sides of the anion membrane (202), the working state of the anion membrane (202) is determined. If the working state of the anion membrane (202) is lower than a preset value, the first ion sensor (7) and the second ion sensor (8) send an alarm to the staff through the prompter. At this time, the staff takes a new membrane assembly (2) and makes it slide along the extension groove (11) and push the membrane assembly (2) inside the electrolytic cell (1) until the membrane assembly (2) inside the electrolytic cell (1) passes through the penetration opening (9) along the limiting slide groove (10) and is discharged from the electrolytic cell (1), and the new membrane assembly (2) replaces the original membrane assembly (2) and continues to operate.

Images