WO2016107294A1

WO2016107294A1 - Method for filling through hole by electroplating

Info

Publication number: WO2016107294A1
Application number: PCT/CN2015/094365
Authority: WO
Inventors: 谢添华; 崔正丹; 李志东
Original assignee: 广州兴森快捷电路科技有限公司; 深圳市兴森快捷电路科技股份有限公司; 宜兴硅谷电子科技有限公司
Priority date: 2014-12-31
Filing date: 2015-11-12
Publication date: 2016-07-07
Also published as: CN104532318A

Abstract

A method for filling a through hole by electroplating. The method comprises the following steps: 1) using an electroplating device; 2) connecting a to-be-electroplated piece that has a through hole to the negative electrode of a power source, and placing the piece into an electroplating solution in an electroplating bath; 3) controlling the power source to work according to a control condition, and continuously electroplating the piece for T time, wherein T>0, the control condition is that: within an initial stage T1 period, a current density J1 of the to-be-electroplated piece ranges from 2 ASD to 3 ASD, and 30%≤T1/T≤50%; in a mid-term stage T2 period, a current density J2 of the to-be-electroplated piece ranges from 0.5 ASD to 1.5 ASD, and 20%≤T2/T≤40%; and in a terminal stage T3 period, a current density J3 of the to-be-electroplated piece ranges from 1.0 ASD to 2.0 ASD, T3=T-T1-T2，and J1>J3>J2. The method can relatively reduce time used for filling a through hole and helps to improve the production efficiency.

Description

Method for plating through holes

Technical field

This invention relates to electroplating techniques, and more particularly to a method of electroplating filled vias.

Background technique

In the manufacturing process of printed circuit boards, it is necessary to fill the through holes on the printed circuit board; at present, the through holes are usually filled by the plating through hole technology.

Generally, the electroplating apparatus comprises a plating tank, a plating solution, a power source, an anode, a plating solution is arranged in the plating tank, an anode is connected to the anode of the power source, and the anode is placed in the plating solution of the plating tank. The electroplating apparatus is usually also provided with a jetting device connected to the plating tank, and the jetting device is provided with a nozzle, and the nozzle is provided with a nozzle. The jetting device draws in the plating solution in the plating bath and ejects it from the nozzle into the plating bath to drive the plating solution to flow in the plating bath.

At present, when the plating device is used to fill the through hole, the member to be plated with the through hole is used as a cathode, connected to the negative electrode of the power source, and then the member to be plated with the through hole is placed in the plating solution of the plating bath. The power supply is then controlled to supply power to the anode and cathode, and electroplating is performed at a constant current density for a constant time to complete the fill via. For example, for a via hole having a hole diameter of 80-100 μm and a hole depth of 100-150 μm, under the premise of achieving a certain filling effect (the hole recess value is 16-22 μm), the filling method is performed according to the current plating filling hole method. Hole, plating time should be 70-80min.

However, the current plating fill-through method requires a relatively long plating time, resulting in reduced production efficiency.

Summary of the invention

Based on this, it is necessary to provide a method for plating the through-holes for the problem of long time for plating the through-holes, which can relatively reduce the filling time of the through-holes, and is advantageous for improving production efficiency.

A method of plating a through hole, comprising the steps of:

1) using an electroplating device, the electroplating device comprises a plating tank, a plating solution, a power source, an anode, a plating solution is arranged in the plating tank, an anode is connected to the anode of the power source, and the anode is placed in the plating solution of the plating tank;

2) connecting the member to be plated with the through hole to the negative electrode of the power source, and placing the plating solution in the plating bath in;

3) Control the power supply according to the control conditions, and perform continuous plating at T time, T>0; the control conditions are:

In the initial stage T1, the current density J1 of the member to be plated is 2-3 ASD, 30% ≤ T1/T ≤ 50%,

In the mid-stage T2, the current density J2 of the parts to be plated is 0.5-1.5 ASD, 20% ≤ T1/T ≤ 40%,

In the final stage T3, the current density J3 of the member to be plated is 1.0-2.0 ASD, T3=T-T1-T2, and J1>J3>J2.

In one embodiment, the electroplating apparatus in step 1) further comprises a jetting device connected to the electroplating tank, the jetting device being provided with a nozzle located in the electroplating tank;

Step 3) Specifically, controlling the power supply operation according to the control condition and controlling the jet flow device to perform the side jet flow, and performing continuous plating for T time; the control condition is:

In the initial stage T1, the current density J1 of the material to be plated is 2-3 ASD, the nozzle flow rate q1 is 1.5-2 L/min, 30% ≤ T1/T ≤ 50%;

In the intermediate period T2, the current density J2 of the material to be plated is 0.5-1.5 ASD, the nozzle flow rate q2 is 3-5 L/min, 20% ≤ T1/T ≤ 40%;

In the final stage T3, the current density J3 of the parts to be plated is 1.0-2.0 ASD, the nozzle flow rate q3 is 2-3 L/min, T3=T-T1-T2, J1>J3>J2, q2>q3>q1.

The method of the present invention controls the power supply operation to perform electroplating correspondingly in the three stages of the electroplating process in accordance with the current density of the material to be plated. After testing, the method of the present invention has the following good effects compared to the existing method: The same through-hole filling effect is achieved, and the plating time is small; the plating time is the same, and the through-hole filling effect is good. Therefore, the present invention can relatively reduce the filling time of the through holes, which is advantageous for improving production efficiency.

The method of the present invention cooperates with the operation of controlling the jet flow device in the case of controlling the operation of the power source, so that the through hole filling effect is further improved.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of a plating apparatus for carrying out the method of the present invention.

detailed description

Embodiment 1

A method of plating a through hole, comprising the steps of:

1) As shown in FIG. 1 , an electroplating apparatus is used. The electroplating apparatus includes a plating tank 1, a plating solution 2, a power source 3, and an anode 4. The plating tank 1 is provided with a plating solution 2, the anode 4 is connected to the anode of the power source 5, and the anode 4 is placed. In the plating solution 2 of the plating bath 1;

2) connecting the member to be plated 6 with the through hole 61 to the negative electrode of the power source 5, and placing it in the plating solution 2 of the plating tank 1;

In this step, the member to be plated 6 with the through hole 61 is connected as a cathode to the power source 5, and the plate to be plated 6 forms a circuit with the power source 5 and the anode 4 under the action of the plating solution.

3) Control the power supply 3 according to the control conditions, and perform continuous plating at T time, T>0; the control conditions are:

During the initial period T1, the current density J1 of the member to be plated 6 is 2-3 ASD, 30% ≤ T1/T ≤ 50%,

In the intermediate period T2, the current density J2 of the member to be plated 6 is 0.5-1.5 ASD, 20% ≤ T1/T ≤ 40%,

In the final stage T3, the current density J3 of the member to be plated 6 is 1.0-2.0 ASD, T3=T-T1-T2, and J1>J3>J2.

In step 3), the adjustment of the current density of the member to be plated 6 is achieved by controlling the output value of the power source.

For different parts to be plated (in this application, the size of the through holes is mainly emphasized), to achieve a certain through hole filling effect, the time required for electroplating under the same conditions is different; for the same piece to be plated, Different via fill effects are reached, and the time required to perform the plating under the same conditions is also different. The size of the time T of continuous plating in the method needs to be determined in consideration of the final required through-hole filling effect. The technical core of the method is to control the power supply 3 to perform electroplating according to the current density of the material to be plated 6 in three successive stages of the electroplating process. After testing, the method has the following advantages compared with the existing method. Effect: achieve the same through hole filling effect, less plating time; plating time phase Similarly, the through hole filling effect is good.

The through holes of the same size (the aperture is 80 μm and the hole depth is 100 μm) are plated and filled according to different methods. The test results are shown in Table 1.

Table 1 test results

As can be seen from Table 1, the method of the present invention has a shorter plating time and a higher filling effect of the through holes than the prior art.

Embodiment 2

This embodiment is based on the first embodiment, and cooperates with the control of the jet flow device during the electroplating process.

A method of plating a through hole, comprising the steps of:

1) As shown in FIG. 1 , an electroplating apparatus is used. The electroplating apparatus includes a plating tank 1, a plating solution 2, a power source 3, an anode 4, and a jetting device 5. The plating tank 1 is provided with a plating solution 2, a jetting device 5 and plating. The tank 1 is connected, the nozzle device 5 is provided with a nozzle 51 located in the plating tank 1, the anode 4 is connected to the anode of the power source 5, and the anode 4 is placed in the plating solution 2 of the plating tank 1;

The jet flow device 5 sucks the plating solution 2 in the plating tank 1 and ejects it from the nozzle 51 into the plating tank 1 to drive the plating solution 2 to flow in the plating tank 1, so that the plating solution 2 is more uniform.

3) Control the power supply 3 according to the control conditions and control the jet flow device 5 to perform side jet flow, and perform continuous plating for T time; the control conditions are:

During the initial period T1, the current density J1 of the member to be plated 6 is 2-3 ASD, the nozzle flow rate q1 is 1.5-2 L/min, and 30% ≤ T1/T ≤ 50%;

In the intermediate period T2, the current density J2 of the member to be plated 6 is 0.5-1.5 ASD, the nozzle flow rate q2 is 3-5 L L/min, 20% ≤ T1/T ≤ 40%;

In the final stage T3, the current density J3 of the member to be plated 6 is 1.0-2.0 ASD, the nozzle flow rate q3 is 2-3 L/min, T3=T-T1-T2, J1>J3>J2, q2>q3>q1 .

The nozzle flow rate refers to the flow rate of the nozzle in unit time, and the unit is L/min. The side jet means that the spray direction of the nozzle is perpendicular to the plate surface of the member to be plated, that is, the hole axis which is balanced with the through hole of the member to be plated.

The method is based on the first embodiment, in combination with the operation of controlling the jet flow device during the electroplating process, using different nozzle flow rates in the three electroplating stages, and the effect of the method is tested in the effect of the first embodiment method. On the basis of this, there is further improvement.

The through holes of the same size (pore size 80 μm, hole depth 100 μm) were electroplated and filled according to the method of the present invention, and the test results are shown in Table 2.

Table 2 test results

It can be seen from the comparison between Table 1 and Table 2 that the method of the present invention of the present embodiment is further improved in the filling effect of the through holes in the case of the method of the present invention in the first embodiment.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A method of plating a through hole, comprising the steps of:

1) using an electroplating device, the electroplating device comprises a plating tank, a plating solution, a power source, an anode, a plating solution is arranged in the plating tank, an anode is connected to the anode of the power source, and the anode is placed in the plating solution of the plating tank;

2) connecting the member to be plated with the through hole to the negative electrode of the power source, and placing it in the plating solution of the plating tank;

3) Control the power supply according to the control conditions, and perform continuous plating at T time, T>0; the control conditions are:

In the initial stage T1, the current density J1 of the member to be plated is 2-3 ASD, 30% ≤ T1/T ≤ 50%,

In the mid-stage T2, the current density J2 of the parts to be plated is 0.5-1.5 ASD, 20% ≤ T1/T ≤ 40%,

In the final stage T3, the current density J3 of the member to be plated is 1.0-2.0 ASD, T3=T-T1-T2, and J1>J3>J2.
A method of plating a via hole according to claim 1, wherein

The electroplating apparatus in the step 1) further includes a jetting device connected to the plating tank, and the jetting device is provided with a nozzle located in the plating tank;

Step 3) Specifically, controlling the power supply operation according to the control condition and controlling the jet flow device to perform the side jet flow, and performing continuous plating for T time; the control condition is:

In the initial stage T1, the current density J1 of the material to be plated is 2-3 ASD, the nozzle flow rate q1 is 1.5-2 L/min, 30% ≤ T1/T ≤ 50%;

In the intermediate period T2, the current density J2 of the material to be plated is 0.5-1.5 ASD, the nozzle flow rate q2 is 3-5 L/min, 20% ≤ T1/T ≤ 40%;

In the final stage T3, the current density J3 of the parts to be plated is 1.0-2.0 ASD, the nozzle flow rate q3 is 2-3 L/min, T3=T-T1-T2, J1>J3>J2, q2>q3>q1.