JPH05335459A - Electroplating apparatus - Google Patents

Abstract

PURPOSE:To always monitor a film thickness of a plated material during a plating step by calculating data of a current pattern at a normal time to store a measured value of a current of electroplating and monitoring the plating current. CONSTITUTION:The electroplating apparatus comprises a memory circuit 12 having a shunt resistor 6 interposed at an intermediate part of a lead 5 to store a current value measured through the resistor 6 in a time series, and a comparison deciding unit 11 for calculating data of the current value in the circuit 12 and a measured current value during plating and having a deciding circuit 13 for deciding the calculated value. Thus, since a film thickness of the plated material can be always inspected during a plating step, it is not necessary to remove an IC lead frame and to measure its thickness at each time and easy to check uniform plated layer. Its yield can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroplating apparatus capable of inspecting a film thickness of a material to be plated during a plating process in electroplating for plating a relatively small area.

[0002]

2. Description of the Related Art Conventionally, when electroplating a printed circuit board or the like in an electronic component manufacturing plant, etc., a plating solution tank is enlarged to contain a large amount of electrolytic solution (silver ion etc.), and a large current is used to make a large number of electrolytic solution at a time. It processes things to increase productivity. Even if electronic parts such as printed circuit boards became smaller, they could be used if the plating film layer was thick.

In the IC lead frame, the uniformity of the coating layer is a problem. After setting the current and time for growing the plating film thickness, the plating operation is continuously performed, and the plating film thickness is checked by the sampling inspection. It manages. Some film thickness meters used for the sampling inspection use fluorescent X-rays or the like.

Further, regarding the concentration of the plating liquid, a counter is used to count the number of times of use, and the plating liquid is replenished when a predetermined number is reached. For abnormalities in the power supply used, a meter relay is connected. Measures are taken to monitor the current value and stop the device in the event of an abnormality.

[0005]

However, in the sampling inspection, when a defect is found, it is necessary to go back through the process and check all the products after the previous sampling inspection or dispose of a predetermined number of lots. I won't. Further, in the above-mentioned film thickness meter, the parts to be plated have to be set at the measuring points one by one, which causes a problem that the device becomes large and complicated. In addition, if a counter or meter relay is used separately, human or mechanical error is likely to occur. In other words, if the count of the number of used sheets is set smaller than the actual count, defective products will occur due to the decrease in the concentration of the plating solution. Further, at the initial stage of energization, the current may be small and an alarm may be generated to inform the user of the abnormality. If a timer or the like that ignores the initial stage of energization is attached, another problem that an abnormality in this time zone cannot be found occurs.

An object of the present invention is to provide an electroplating apparatus which can constantly monitor the total number of materials to be plated during the plating process.

[0007]

In order to achieve the above object, the present invention provides a DC power supply device having a voltage control circuit and an IC.
A plating bath for plating a lead frame or the like is provided, and an electrode arranged in an electrolytic solution filled in the plating bath is connected to the DC power supply device via a lead wire in an electroplating device, An intermediate part has a current extracting means, and has a memory circuit for accommodating current values measured through the current extracting means in time series, and data of the current value in the memory circuit and current measurement during plating. It is characterized in that a comparison and determination device is provided which has a determination circuit for calculating a value and determining the calculated value.

[0008]

According to the present invention, by adopting the above configuration, the change in the current flowing in the electrolytic solution is converted into the change in the voltage by the current extracting means, and the current value (voltage change) gradually measured by the comparison and determination device is stored in time series. Can be stored in the circuit. Then, the upper limit current value and the lower limit current value at the normal time can be drawn from the memory circuit and compared with the current measurement value during plating,
Abnormalities in current changes in the electrolytic solution, abnormalities in the concentration of the electrolytic solution, and film thickness generation can be detected by calculating with time-series current data. Further, when an abnormality is detected, a machine stop signal can be sent to stop the machine.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, a DC power supply device 1 of an electroplating apparatus has a voltage control circuit inside, and a plating solution tank 2 is provided with a fixed electrode 3 and a clamp electrode 4. The two lead wires 5 extending from the DC power supply device 1 are connected to the fixed electrode 3 and the clamp electrode 4, and
A shunt resistor 6 is provided in the intermediate portion of the clamp electrode 4 as a current extracting means. In addition, a magnetic sensor or the like may be attached as the current extracting means.

By the way, in the electroplating process, the film of oil or the like is removed from the IC lead frame 7 put in the plating solution tank 2 in the pretreatment step 8, and the IC lead frame 7 is sandwiched between the clamp electrodes 4 to electrolyze the plating solution tank 2. Put in liquid and set. After the plating is finished, in a post-treatment 9, leak inspection, top coating, etc. are performed.

On the other hand, both ends of the shunt resistor 6 are separately connected to the input ends of the amplifier 10. The amplifier 10 is connected to the input terminal of the comparison / determination device 11. Comparison judgment device
Reference numeral 11 includes a memory circuit 12 and a determination circuit 13, and an output terminal 14 is provided.

The memory circuit 12 is capable of accommodating current values measured in time series, and as shown in FIG. 2, finely records the current change divided into a rise time 15, a stable time 16 and a fall time 17. The upper limit data 18 and the lower limit data 19 can be prepared in time series. At the initial stabilization time 16, the magnitude of the plating current is confirmed as indicated by the arrow, and at the fall time 17, the length of plating required time is confirmed as indicated by the arrow.

The judgment circuit 13 calculates the measured value during plating with the upper limit data 18 and the lower limit data 19, and judges the calculated value to detect an abnormality. The detection signal is output to the output terminal 14. To be done. If there is no abnormality, the measured value 20 during plating is displayed as data between the upper limit data 18 and the lower limit data 19, as shown in FIG.

Next, the operation will be described. Since the electrolytic solution in the plating solution tank 2 reduces the current flow when the concentration becomes thin, it is sufficient to check the voltage change with the shunt resistor 6, but since it changes at the rising time 15 as described above, first. , The plating operation is repeated several times, and the measurement data is collected and divided into the upper limit data 18 and the lower limit data 19 in time series and stored in the memory circuit 12, and the measured value 20 during the plating is calculated and calculated as the stored data. Therefore, it is possible to detect the abnormality early.

The thickness of the plating layer can be made uniform by setting the pattern according to the upper limit data 18 and the lower limit data 19 of the plating current. Further, when the voltage supplied from the DC power supply device 1 fundamentally fluctuates during the plating, the measured value 20 fluctuates, and therefore the abnormality can be detected by the calculation of the upper limit data 18 and the lower limit data 19. .. Further, a detection signal for notifying an abnormality is output from the output end 14 of the comparison and determination device 11, and by sending the detection signal to the machine, it becomes possible to stop putting the IC lead frame 7 into the plating solution tank 2. This makes it possible to reduce the yield.

[0016]

Since the present invention is configured as described above, the measured value of the electric current used for electroplating is calculated with the stored data of the normal current pattern to monitor the plating current. It is not necessary to take out the IC lead frame one by one and measure the film thickness, and it becomes easy to check that the plated layer is uniformly formed.

[Brief description of drawings]

FIG. 1 is a schematic view of a monitoring device for an electroplating process according to an embodiment of the present invention.

FIG. 2 is a graph showing a change in current in a plating solution tank during an electroplating process of an example.

[Explanation of symbols]

 1 DC power supply device 2 Plating liquid tank 3 Electrode 5 Lead wire 6 Current extraction means 7 IC lead frame 11 Comparison judgment device 12 Memory circuit 13 Judgment circuit

Claims (1)

[Claims] 1. A DC power supply device having a voltage control circuit and I
A plating bath for plating C lead frame etc. is provided,
In an electroplating apparatus in which an electrode arranged in an electrolytic solution filled in the plating solution tank is connected to the DC power supply device via a lead wire, a current extracting means is interposed in the middle of the lead wire to extract the current. Having a memory circuit for accommodating the current value measured through the means in time series, calculating the current value data in the memory circuit and the current measurement value during plating, and determining the calculated value An electroplating apparatus comprising a comparison / determination device having a determination circuit.