CN114075689B

CN114075689B - Control method for electroplating PCB and electroplating system

Info

Publication number: CN114075689B
Application number: CN202010852466.XA
Authority: CN
Inventors: 张利华; 钱浩; 许愿; 袁锡志; 冷科; 刘金峰
Original assignee: Shennan Circuit Co Ltd
Current assignee: Shennan Circuit Co Ltd
Priority date: 2020-08-21
Filing date: 2020-08-21
Publication date: 2022-11-22
Anticipated expiration: 2040-08-21
Also published as: CN114075689A

Abstract

The invention provides the technical field of electroplating of PCBs, and particularly relates to a control method and an electroplating system of an electroplating PCB. The control method comprises the following steps: clamping two opposite ends of the PCB in an electroplating solution through a first clamping piece and a second clamping piece; in the electroplating process, periodically switching two electroplating modes until the electroplating operation of the PCB is completed; and one electroplating mode is to control the first clamping piece to be switched into a conductive state and control the second clamping piece to be switched into a cathode, and the other electroplating mode is to control the first clamping piece to be switched into the cathode and control the second clamping piece to be switched into the conductive state. The PCB is electrically conducted through one end, the cathode is arranged at the other end, a certain drainage effect is provided, partial current is absorbed to improve the current distribution on the PCB, and periodic switching is performed, so that the current density is uniform, the current is prevented from being gathered at a sharp corner or an edge, and the current density is gradually reduced along with the distribution of the current with the distance.

Description

Control method for electroplating PCB and electroplating system

Technical Field

The invention provides the technical field of electroplating of PCBs, and particularly relates to a control method and an electroplating system of an electroplating PCB.

Background

Along with the rapid development of the electronic industry, the requirements for the PCB are also higher and higher, such as the fine circuit, the impedance control, and even the plate thickness control, but the existing copper electroplating process is difficult to achieve good uniformity, so that the copper electroplating process becomes a main factor restricting the continuous forward development of the fine circuit and the impedance control, and in addition, the processes of electroplating nickel, gold, tin, and the like also have strong demands for improving the uniformity of the plating layer.

The electroplating process is a method for laying a layer of metal on a conductor by utilizing the principle of electrolysis. Electroplating is a surface processing method in which cations of a pre-plated metal in a plating solution are deposited on the surface of a base metal by electrolysis using the base metal to be plated as a cathode in a salt solution containing the pre-plated metal to form a plating layer. In the electroplating process, the main reason that the uniformity of the plating layer is difficult to control is uneven current distribution, which easily causes the problem that electric lines of force are easily concentrated at sharp corners and edges when the electroplating process faces a PCB with a complex structure.

In addition, the electroplating copper is generally designed by using a one-way clamp, and referring to fig. 1, one end of the PCB 20 is clamped by the one-way clamp 210, and the above-mentioned one-way clamping electroplating easily causes the distribution of current density to be gradually reduced, that is, the current density near the clamping point is large, and the current density at the clamping point is small. And, the nickel-gold plating may be designed using a double-sided jig, and referring to fig. 2, both ends of the PCB panel 20 are clamped by the double-sided jig (220 and 230), but when the double-sided current is simultaneously turned on, a phenomenon occurs in which the plating layer in the PCB panel 20 is thin and the plating layer at the edge thereof is thick due to the mutual interference of the power lines.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a control method and an electroplating system for electroplating a PCB, aiming at the above-mentioned defects in the prior art, so as to solve the problem that the current uniformity of the PCB cannot be achieved by the current electroplating process.

The technical scheme adopted by the invention for solving the technical problems is as follows: provided is a control method of an electroplated PCB board, comprising the following steps:

clamping two opposite ends of the PCB in an electroplating solution through a first clamping piece and a second clamping piece;

in the electroplating process, periodically switching two electroplating modes until the electroplating operation of the PCB is completed;

and one electroplating mode is to control the first clamping piece to be switched into a conductive state and control the second clamping piece to be switched into a cathode, and the other electroplating mode is to control the first clamping piece to be switched into the cathode and control the second clamping piece to be switched into the conductive state.

Wherein, the preferred scheme is: the first or second clamp is smoothly switched from a conductive state to a cathode, and the first or second clamp is smoothly switched from the cathode to the conductive state.

Preferably, the step of smoothly switching the first clamping member or the second clamping member from the conductive state to the cathode comprises: the first clamping piece or the second clamping piece slowly reduces the voltage until the cathode is switched.

Preferably, the step of smoothly switching the first clamping member or the second clamping member from the cathode to the conductive state comprises: and the voltage of the first clamping piece or the second clamping piece is slowly increased until a preset voltage value is reached.

Wherein, the preferred scheme is: the working current of the first clamping piece or the second clamping piece in the conducting state is sinusoidal distributed current.

Wherein, the preferred scheme is: the first clamping piece and the second clamping piece are of multi-clamping-point structures and clamp the conductive wire on the surface of the PCB.

Preferably, the plurality of clamping points of the first clamping member and the second clamping member are uniformly distributed at two opposite ends of the PCB.

The technical scheme adopted by the invention for solving the technical problem is as follows: the PCB electroplating system comprises a cavity for storing electroplating solution, a first clamping piece, a second clamping piece, a driving device and a control unit, wherein the first clamping piece and the second clamping piece clamp two opposite ends of the PCB in the electroplating solution of the cavity, the driving device is respectively connected with the first clamping piece, the second clamping piece and the control unit, the driving device supplies power to the first clamping piece or the second clamping piece or switches the first clamping piece or the second clamping piece into a cathode under the control of the control unit, and the control unit can realize the control method.

Wherein, the preferred scheme is: the driving device comprises two driving circuits which respectively and independently control the corresponding first clamping piece or second clamping piece so as to supply power or ground.

Compared with the prior art, the electroplating solution has the advantages that one end of the electroplating solution conducts electricity to the PCB, the cathode is arranged at the other end of the electroplating solution to provide a certain drainage effect, partial current is absorbed to improve current distribution on the PCB, periodic switching is carried out, current density is uniform, current is prevented from being gathered to sharp corners or edges, the current density is gradually reduced along with the distance increasing, and the uniformity of electroplating is improved.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic structural view of a prior art single-sided jig plating apparatus;

FIG. 2 is a schematic structural view of a prior art double-sided fixture electroplating apparatus;

FIG. 3 is a schematic structural diagram of a control method for electroplating a PCB board according to the present invention;

FIG. 4 is a schematic view of the electroplating apparatus shown in FIG. 3;

FIG. 5 is a schematic diagram of an electroplating system according to the present invention.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in fig. 3 and 4, the present invention provides a preferred embodiment of a control method of plating a PCB panel.

A control method of electroplating a PCB panel 10, the steps of the control method comprising:

step S00, two electroplating modes are set, wherein one electroplating mode is to control the first clamping piece 111 to be switched to a conductive state and control the second clamping piece 112 to be switched to a cathode, and the other electroplating mode is to control the first clamping piece 111 to be switched to the cathode and control the second clamping piece 112 to be switched to the conductive state;

step S10, clamping two opposite ends of the PCB 10 in an electroplating solution through a first clamping piece 111 and a second clamping piece 112;

step S20, periodically switching two electroplating modes in the electroplating process;

and step S30, finishing the electroplating operation of the PCB 10 and dismounting the PCB 10.

Specifically, in step S00, two sets of electroplating modes are preset, that is, states of the first clamping member 111 and the second clamping member 112 when the PCB 10 is electroplated are controlled, and meanwhile, the preset parameters may be used as control parameters of the electroplating modes, and parameters may be selected or adjusted according to specific conditions, such as the type, area, thickness, and wiring conditions of the PCB 10. The core of the two electroplating modes is that one end conducts electricity to the PCB 10, electroplating operation is carried out on the PCB 10, in order to enable the current 1111 on the PCB 10 to be more uniform, the current 1111 is prevented from being gathered to sharp corners or edges, and the current density is gradually reduced along with the distance increasing, a cathode is arranged at the other end to provide a certain drainage effect, and partial current 1111 is absorbed to improve the current distribution on the PCB 10, so that the current density is uniform, and the electroplating uniformity is improved; preferably, the first clamping member 111 and the second clamping member 112 are independently controlled in a branching manner to prevent mutual interference.

In step S10, the first clamping member 111 and the second clamping member 112 are controlled to respectively clamp two opposite ends of the PCB 10 through manual operation, automatic mechanical driving operation or semi-automatic mechanical operation, so that one end is conductive and the other end conducts current. Certainly, in order to improve the uniformity of current distribution on the PCB 10, the first clamping member 111 and the second clamping member 112 are both of a multi-point structure, that is, the PCB 10 is electrically conducted through multiple points, and meanwhile, current is conducted through multiple points at the other end; preferably, the multi-pinch structure clamps the conductive wire on the surface of the PCB, so that the conductive wire conducts current in the electroplating solution, and the electroplating balance is improved; further, the plurality of pinch points of the first and

second clamping members

111 and 112 are uniformly distributed at two opposite ends of the PCB 10, so that the current density is more uniform.

In step S20, periodically switching two electroplating modes according to a preset time or the time set in step S00, that is, firstly controlling the first clamping member 111 and the second clamping member 112 to electroplate the PCB 10 according to one electroplating mode, after the preset time elapses, switching to another electroplating mode to control the first clamping member 111 and the second clamping member 112 to electroplate the PCB 10, and repeatedly switching between the two electroplating modes until the electroplating operation of the PCB 10 is completed; the electroplating condition of the PCB 10 can be acquired according to detection equipment, artificial visual detection or semi-artificial semi-equipment detection, so that the electroplating operation can be completed under active control, and the electroplating operation can also be completed under intelligent control according to preset time or the detection condition of the detection equipment.

In step S30, after the PCB 10 is detached, a new PCB 10 is attached, that is, the process returns to step S10 repeatedly, and the new PCB 10 is subjected to the plating operation, but it is also possible to return to step S00, reset the parameters, manually set the parameters, or intelligently select or adjust the parameters according to the type, area, thickness, wiring condition, and the like of the PCB 10. The unloading of the PCB 10 may also be performed by manual operation, automated mechanical driving operation, or semi-automated mechanical operation, and the first clamping member 111 and the second clamping member 112 are controlled to respectively loosen two opposite ends of the PCB 10, and in the automated mechanical driving operation, a transportation device, such as a pipeline or a manipulator, may be further provided to perform loading and unloading of the PCB 10.

In the present invention, a preferred embodiment of a smoothing control method is provided.

The first or

second clamp

111 or 112 is smoothly switched from a conductive state to a cathode, and the first or

second clamp

111 or 112 is smoothly switched from a cathode to a conductive state. Specifically, the step of smoothly switching the first clamping member 111 or the second clamping member 112 from the conductive state to the cathode includes: the first clamping member 111 or the second clamping member 112 slowly reduces the voltage until the cathode is switched. And the step of smoothly switching the first clamping member 111 or the second clamping member 112 from the cathode to the conductive state includes: the voltage of the first clamping member 111 or the second clamping member 112 is slowly increased until a preset voltage value is reached. Through control operating voltage, from high to zero, realize electrically conductive to the dynamic smooth control of negative pole switching to and control operating voltage slowly risees from zero, when up to predetermineeing operating voltage, realize the dynamic smooth control that the negative pole switched into conductive state, reduce the current line confusion that the fast switch-over leads to, influence the problem of electroplating effect.

Of course, it is also possible to stay between the two plating modes for a period of time, waiting for the current on the PCB 10 to slowly disappear, without affecting the next plating operation.

In this embodiment, the working current of the first clamping member 111 or the second clamping member 112 in the conductive state is a sinusoidal distributed current, so as to further perform dynamic smooth control, so that the PCB 10 forms a dynamic control process during the electroplating operation, and a uniform, feasible and smooth current transition is maintained.

As shown in fig. 5, the present invention provides a preferred embodiment of an electroplating system for electroplating a PCB board.

The electroplating system of the PCB 10 is characterized by comprising a first clamping piece 111, a second clamping piece 112, a driving device 120 and a control unit 130, wherein the driving device 120 is respectively connected with the first clamping piece 111, the second clamping piece 112 and the control unit 130, the first clamping piece 111 and the second clamping piece 112 clamp two opposite ends of the PCB 10, the driving device 120 supplies power to the first clamping piece 111 or the second clamping piece 112 or switches the power to a cathode under the control of the control unit 130, and the control unit 130 can realize a control method.

The driving device 120 controls the first clamping member 111 and the second clamping member 112 to switch between the conducting state and the cathode, and preferably, the driving device 120 may be provided with two sets of driving circuits, which individually control the corresponding first clamping member 111 or second clamping member 112 to supply power or ground. Meanwhile, the control unit 130 may perform parameter setting, mode storage, and program control to control the driving device 120 to perform different operations, for example, periodically switch two plating modes by the first clamping member 111 and the second clamping member 112.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, but rather as embodying the invention in a wide variety of equivalent variations and modifications within the scope of the appended claims.

Claims

1. A control method for electroplating a PCB is characterized by comprising the following steps:

and the other electroplating mode is to control the first clamping piece to be switched into the cathode and control the second clamping piece to be switched into the conductive state.

2. The control method according to claim 1, characterized in that: the first or second clamp is smoothly switched from a conductive state to a cathode, and the first or second clamp is smoothly switched from the cathode to the conductive state.

3. The control method according to claim 2, wherein the step of smoothly switching the first or second clamp from the conductive state to the cathode comprises: and the voltage of the first clamping piece or the second clamping piece is slowly reduced until the first clamping piece or the second clamping piece is switched into a cathode.

4. The control method according to claim 2, wherein the step of smoothly switching the first or second clamping member from the cathode to the conductive state includes: and the voltage of the first clamping piece or the second clamping piece is slowly increased until a preset voltage value is reached.

5. The control method according to any one of claims 1 to 4, characterized in that: the working current of the first clamping piece or the second clamping piece in the conducting state is sinusoidal distributed current.

6. The control method according to any one of claims 1 to 4, characterized in that: the first clamping piece and the second clamping piece are of multi-clamping-point structures and clamp the conductive wire on the surface of the PCB.

7. The control method of claim 6, wherein the plurality of pinch points of the first and second clamping members are evenly distributed at both ends of the PCB board.

8. An electroplating system of a PCB is characterized by comprising a cavity for storing electroplating solution, a first clamping piece, a second clamping piece, a driving device and a control unit, wherein the first clamping piece and the second clamping piece clamp two opposite ends of the PCB in the electroplating solution in the cavity, the driving device is respectively connected with the first clamping piece, the second clamping piece and the control unit, the driving device supplies power to the first clamping piece or the second clamping piece or switches the first clamping piece or the second clamping piece into a cathode under the control of the control unit, and the control unit can realize the control method according to any one of claims 1 to 7.

9. The plating system of claim 8, wherein: the driving device comprises two driving circuits which respectively control the corresponding first clamping piece or the second clamping piece to supply power or ground.