JPH0841700A - Electrolytic polishing equipment for strips - Google Patents

Abstract

(57) [Summary] (Corrected) [Objective] To provide a strip material electrolytic polishing apparatus capable of rapidly and effectively polishing the surface of a lead frame without causing deformation. [Structure] First cathode arrangement tank 17, first treatment liquid discharge tank 14, first anode arrangement tank 15, second treatment liquid discharge tank 16, second anode arrangement tank 17, third treatment liquid from the introduction direction of the strip material. Discharge tank 1
8 and a second cathode placement tank 19 are arranged in this order, and each tank is partitioned by a partition having an opening 20 for passing a strip material to be subjected to electrolytic polishing treatment. , 19, the cathode plate 5 connected to the cathode 41 of the power source is arranged, and further, the first and second anode placement tanks 15,
An anode plate connected to the anode 42 of the power source is arranged at 17, and electropolishing is performed at the bottoms of the first and second cathode placement tanks 13 and 19 and the first and second anode placement tanks 15 and 17, respectively. A liquid inlet 25 is provided, and an electrolytic polishing liquid outlet 26 is provided at the bottom of each of the first to third processing liquid discharge tanks 16 and 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic polishing apparatus for carrying out a polishing treatment for the purpose of cleaning and smoothing the surface of a strip material before applying a plating film to the surface thereof.

[0002]

2. Description of the Related Art In the electronic equipment industry, which has been growing rapidly in recent years, as a material for lead frames, the production and consumption of which are increasing, rolled materials are generally used. It is used in a state in which a plating film is formed on the obtained lead portion or the lead portion which has been dissolved in the unnecessary portion by etching and left on the material.

In this case, there are many fine recesses with a depth of 1 μm or less on the surface of the rolled strip. As the shape of this recess, even if the area near the surface of the strip is narrow, but if an area space that greatly expands toward the inside of the strip is formed, the plating film is directly applied to the surface of the strip. Even if it is formed, it often causes unevenness in the plating film thickness or partial swelling of the plating film, which increases the incidence of rejected products during product inspection, resulting in a market failure. It is well predicted that you will be left out of the competition.

In order to improve these situations, it has become common for the surface of the strip to be subjected to electrolytic polishing treatment prior to the plating treatment.

Conventionally, an electrolytic polishing apparatus as shown in FIG. 2 has been used as an apparatus for electrolytically polishing the surface of a strip material when manufacturing a lead frame.

In this apparatus, a plurality of feed rolls 2 made of an insulating material are provided in an electrolytic polishing tank 1 at intervals along a horizontal plane, and all the feed rolls 2 rotate in the same direction. Has been. Further, the lead frame strip 7 is moved in contact with the upper portions of the feed rolls 2. On the upper surface of the strip 7, a power supply roll 3 is arranged so as to be in contact with the strip 7 and rotate in the opposite direction at the same speed as the feed roll 2. A brush 4 connected to the anode of a power source (not shown) is arranged so as to be in contact with the power feeding roll 3. Further, below the feed roll 2, a cathode plate 5 is provided which extends along the arrangement of the feed roll 2 and is connected to the cathode of a power source (not shown).

When using the above-described electrolytic polishing apparatus that has been conventionally used, the electrolytic polishing liquid 6 is directed toward the inside of the electrolytic polishing tank 1 to such an extent that a part of the power supply roll 3 is exposed to the air.
Then, the belt material 7 is supplied between the feed roll 2 and the power feed roll 3 in a state in which a predetermined power is supplied from the power feed roll 3 to the cathode plate 5 through the electrolytic polishing liquid 6. The surface of the strip was polished.

However, in the polishing process using this apparatus, the current efficiency is lowered due to a contact failure at the contact portion between the power feeding roll 3 and the strip 7 and an electric reaction between the electrodes using the electrolytic polishing liquid 6 as a medium. Furthermore, the feed roll 2
However, problems such as frequent deformation of the strip 7 due to poor rotation of the above have not been solved, and countermeasures against it have been difficult.

On the other hand, as the number of pins of the lead frame has been increased, it is becoming more and more necessary for the thickness of the strip material to be used due to its processing, but in order to secure a thin strip material. Inevitably, an increase in the number of rollings is unavoidable, and it is inevitable that the number of recesses formed on the surface of the strip will relatively increase. The advent of an electropolishing apparatus that can perform flattening quickly and effectively and that can perform surface polishing without causing deformation of the strip has been awaited.

As a result of intensive research and development for solving the above-mentioned problems, the present inventors did not adopt a power supply connection method for directly energizing the band material directly, but energizing it through an electrolytic polishing solution. By adopting a power supply connection method that allows the cathode plate and the anode plate to be considered for their size ratio, and by combining the use of an anode and a cathode that are divided and arranged in separate tanks with partition walls, Found to be resolved.

That is, the applicant of the present invention is August 26, 1993.
In the Japanese patent application (Japanese Patent Application No. 5-234170), an electrolytic polishing technique as shown in FIG. 3 was proposed. That is, the electrolytic polishing tank 1 having a width of 23 cm, a length of 95 cm, and a depth of 15 cm
Eight pairs of upper and lower polyethylene feed rollers 2 having a diameter of 2 cm and a length of 20 cm are provided therein, and a cathode plate 5 made of stainless steel having a width of 7.5 cm, a length of 1.5 cm and a thickness of 0.2 mm.
And the anode plate 8 are alternately arranged between the feed rollers 2 along the horizontal plane of 7 sets.

In the electrolytic polishing tank 1, sulfuric acid 20 g / l, sodium sulfate 10 g / l, nonionic surfactant 0.05
The surface of the electrolytic solution 6 is located slightly above the center of the upper feed roller 2 so that the cathode plate 5 and the anode plate 8 between the upper feed roller 2 are immersed in the electrolytic solution 6 of an aqueous solution containing 4 g / l. So that

The cathode plate 5 is connected to the cathode of the DC power supply, and the anode plate 8 is connected to the anode of the DC power supply, and the cathode current density is 5 A / dm ^2.
The current is applied so that the voltage is constant at each roller, and the rollers rotate in synchronization with each other at the same rotation speed. Width 7.0 cm, length 16.5c
The first is a pair of upper and lower feed rollers 2 (left end in FIG. 3), which is an iron-nickel alloy lead frame strip having a thickness of 100 m and a thickness of 100 μm.
Inserted in between. The time from when the lead frame strip 7 is sandwiched between the first pair of feed rollers 2 to when it is discharged from between the last pair of feed rollers 2 (right end in FIG. 3) is 1
7 seconds. As a result, the current flowing during polishing greatly increases, and the maximum increase amount is 8.2 A (cathode current density conversion 1
7.0 A / dm ² ).

[0014]

DISCLOSURE OF THE INVENTION The present invention further advances the above-mentioned improvements, and electrolytic polishing capable of rapidly and effectively polishing the surface of a strip used for a lead frame without causing deformation. The purpose is to provide a device.

[0015]

SUMMARY OF THE INVENTION A strip material electropolishing apparatus according to the present invention comprises a material supply roll portion,
Electrolytic polishing unit, in the strip material electropolishing apparatus arranged in the order of the material discharge roll unit, the electrolytic polishing unit, the first cathode placement tank, the first treatment liquid discharge tank, the first anode placement tank, from the introduction direction of the strip material, The second treatment liquid discharge tank, the second anode arrangement tank, the third treatment liquid discharge tank, and the second cathode arrangement tank are arranged in this order, and further, each of the above tanks is for passing the strip material used for the electrolytic polishing treatment. Is partitioned by a partition wall having an opening, and the first and second cathode placement tanks have a plane connecting the openings as a boundary,
At either the top or the bottom or the top and bottom, and
A cathode plate connected to the cathode of the power source is arranged at a position immersed in the electrolytic polishing liquid, and further, the first and second anode placement tanks are arranged above and below or above and below the plane connecting the openings. At any position, and at a position immersed in the electrolytic polishing liquid, an anode plate connected to the anode of the power source is arranged, and
The first and second cathode placement tanks and the bottoms of the first and second anode placement tanks are each provided with an electropolishing liquid inlet, and at the bottom of the first to third treatment liquid discharge tanks. Each is provided with an outlet for the electrolytic polishing liquid that has been subjected to the polishing treatment, and further from the above inlet toward the first and second cathode placement tanks or the first and second anode placement tanks. The electropolishing treatment liquids individually injected are the bottoms of the first and second treatment liquid discharge tanks adjacent to the first and second cathode placement tanks or the first and second anode placement tanks, respectively. It is designed to be discharged from the discharge port provided at. Then, the discharged electropolishing liquid is collected in the electropolishing liquid circulation unit, and after adjusting the properties of the electropolishing liquid circulation unit, the first and second cathode placement tanks or first And is preferably circulated and supplied to the inlet of the second anode placement tank. In addition, when the length direction is the traveling direction of the strip and the length relationship between the adjacent cathode plate and anode plate is measured, the length of the cathode plate is always longer than that of the anode plate. Is preferably provided.

[0016]

When electrolytically polishing the strip material for the lead frame, in the apparatus of the present invention, non-contact energization prevents damage to the strip material and also prevents electrical reaction between the electrode plates, thereby performing electrolytic polishing. Increase efficiency. That is, the anode plate and the cathode plate are arranged in separate tanks, and each tank is independent of each other. In this way, the anode plate and the cathode plate are completely cut off, and the reaction between the electrode plates is lost.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIG.

In the embodiment of FIG. 1, the lead frame strip 7 is used.
Material supply roll unit 10 and electrolytic polishing unit 1 from the introduction direction of
1, a strip material electropolishing apparatus 30 in which the material discharge roll unit 12 is arranged in this order. In the electrolytic polishing section 11, the first cathode placement tank 13 and the first treatment liquid discharge tank 1 are arranged from the introduction direction of the strip 7.
4, the first anode placement tank 15, the second treatment liquid discharge tank 16, the second anode placement tank 17, the third treatment liquid discharge tank 18, and the second cathode placement tank 19 are arranged in this order.

Further, each of the above-mentioned tanks is partitioned by a partition wall 21 having an opening 20 for passing the strip 7 to be subjected to electrolytic polishing treatment.

Also, the first and second cathode placement tanks 13,
A cathode plate 5 connected to the cathode 41 of the power source is provided at 19 either above or below the plane connecting the openings 20 and at a position immersed in the electropolishing liquid 6. Arranged, and further, the first and second anode placement tanks 1
The anode plate 8 connected to the anode 42 of the power source is located at the upper and lower positions or at the upper and lower positions with respect to the plane connecting the openings 20, and at the position where the electrolytic polishing liquid 6 is immersed. Are arranged.

The first and second cathode placement tanks 13,
19 and the bottom 24 of each of the first and second anode placement tanks 15 and 17 are provided with an inlet 25 for the electrolytic polishing liquid 6, and the first to third treatment liquid discharge tanks 14 The bottom 24 of each of 16 and 18 is provided with an outlet 26 for the electrolytic polishing liquid used for the polishing process.

Further, the electrolytic polishing liquid 6 individually injected from the injection port 25 into the first and second cathode placement tanks 13 and 19 or the first and second anode placement tanks 15 and 17, A respective first and second cathode placement tank 13,
19 or any one of the first to third processing liquid discharge tanks 14 adjacent to the first and second anode placement tanks 15 and 17,
The liquid is discharged from the discharge port 26 provided at the bottom 24 of the 16, 18 toward the electrolytic polishing liquid circulation unit 27.

Then, the electrolytic polishing liquid 6 which is integrally collected in the electrolytic polishing liquid circulating unit 27 is adjusted in the properties of the electrolytic polishing liquid 6 in the electrolytic polishing liquid circulating unit 27, and then the electrolytic polishing liquid circulating unit 27 is used. Each first and second cathode placement tank 1
3, 19 or first and second anode placement tanks 15, 17
It is circulated and supplied to the injection port 25 of.

Inside the respective tanks of the first and second cathode placement tanks 13 and 19 and the first and second anode placement tanks 15 and 17, there are two partition walls located in front of and behind the traveling direction of the strip 7. The upper and lower rolls 2 are arranged one by one and two pairs of upper and lower rolls 2 are arranged in the front and rear, respectively, in a state of being close to the openings 20 provided in the respective 21 and in a state where the respective openings 20 are positioned in the center. .

When the width direction is perpendicular to the traveling direction of the strip 7, the widths of the cathode plate 5 and the anode plate 8 are larger than those of the strip 7 to be polished. It is formed.

When the traveling direction of the strip 7 is the lengthwise direction, the sum of the lengths of the cathode plate 5 is preferably longer than twice the sum of the lengths of the anode plate 8. further,
When the length relationship between the adjacent cathode plate 5 and anode plate 8 is measured, the length of the cathode plate 5 is always longer than the length of the anode plate 8.

As described above, the strip material electropolishing apparatus 30 including the strip material supply roll unit 10, the electropolishing unit 11, and the strip material discharge roll unit 12 is arranged on the strip material supply roll unit 10 from the introduction direction of the strip material 7. The strip 7 is sent out to the electrolytic polishing section 11 by one or more sets of upper and lower rolls 2.

Next, the first cathode placement tank 13, the first treatment liquid discharge tank 14, and the first anode placement tank 1 from the direction of introduction of the strip material 7.
5, the band 7 is passed through the electrolytic polishing section 11 which is arranged in the order of 5, the second treatment liquid discharge tank 16, the second anode arrangement tank 17, the third treatment liquid discharge tank 18, and the second cathode arrangement tank 19. Each of the tanks 13, 14, 15, 16, 17, 18, 19 in which the electrodes are arranged is the partition wall 2 except only the opening 20 for
The strip 7 is separated by 1 so that the strip 7
Besides, it has the effect of significantly reducing the reactive current that flows.

The first and second cathode placement tanks 13,
The cathode plate 5 is connected to the cathode 41 of the power source at 19 above or below the plane connecting the openings 20 and at a position immersed in the electrolytic polishing liquid 6.
And the first and second anode placement tanks 1
The anode plate 8 connected to the anode 42 of the power source is located at the upper and lower positions or at the upper and lower positions with respect to the plane connecting the openings 20, and at the position where the electrolytic polishing liquid 6 is immersed. Due to the arrangement, the electric current flows from the anode plate 8 connected to the power source to the electrolytic polishing liquid 6 in the anode arrangement tanks 15 and 17, and this current is then passed through the strip 7 to the cathode arrangement tanks 13 and 19. The current flows into the electropolishing liquid 6 inside, and finally a current flows to the cathode plate 5 placed in the cathode placement tanks 13 and 19 to form a circuit.

Although the reason for the reduction in the reactive current generation rate observed when the respective tanks in which the individual electrodes are arranged is isolated is not clear, as a result, the working current efficiency is greatly improved as compared with the conventional one. As will be appreciated, the predetermined current density applied during this time allows the surface of the strip to be rapidly electropolished to a fully satisfactory surface condition during the post-processing.

Further, since the electropolishing treatment of the strip material 7 is carried out by the strip material electropolishing apparatus 30 of this embodiment without contacting the strip material 7, the work can be carried out without causing the strip material 7 to be deformed. The shape defects of are greatly reduced.

The first and second cathode placement tanks 13,
19 and the bottom 24 of each of the first and second anode placement tanks 15 and 17 are provided with an inlet 25 for the electrolytic polishing liquid 6, and the first to third treatment liquid discharge tanks 14 Each of the bottom portions 24 of 16 and 18 is provided with an outlet 26 for the electrolytic polishing liquid used for the polishing treatment.
From the inlet 25 to the first and second cathode placement tanks 1
3, 19 or first and second anode placement tanks 15, 17
The electropolishing liquid 6 injected individually toward the first and second cathode placement tanks 13 and 19 or the first and second anode placement tanks 15 and 17 respectively adjacent to the first to third Bottom 2 of any of the processing liquid discharge tanks 14, 16 and 18
4 is discharged toward the electropolishing liquid circulating portion 27 from the discharge port 26 provided in the No. 4 so that the polarity of the electropolishing liquid 6 in each tank in which the cathode plate 5 or the anode plate 8 is arranged is unified. And succeeded in extremely reducing the reactive current, resulting in improvement of the current efficiency of the electrolytic polishing process.

The electrolytic polishing liquid 6 integrally collected in the electrolytic polishing liquid circulating unit 27 is adjusted in the properties of the electrolytic polishing liquid 6 in the electrolytic polishing liquid circulating unit 27, and then the electrolytic polishing liquid circulating unit 27 is used. Each first and second cathode placement tank 1
3, 19 or first and second anode placement tanks 15, 17
Since it is arranged so as to be circulated and supplied to the injection port 25, the electropolishing liquid 6 in a constant state can always be in contact with the strip material, and the electropolishing work can be performed in a stable state. .

In addition, the first and second cathode placement tanks 1
3, 19 and first and second anode placement tanks 15, 1
In the inside of each tank of No. 7, in a state of being close to the opening 20 provided in each of the two partition walls 21 positioned before and after the band material 7 in the traveling direction, and in the state where each opening 20 is positioned at the center. Since the upper and lower rolls 2 are arranged one by one and the two upper and lower rolls 2 are arranged in the front and rear, the electrolytic polishing liquid 6 flowing along the surface of the strip 7 toward the opening portion.
The flow direction is changed, and the polarity inside each electrode arrangement tank is adjusted, resulting in an increase in current efficiency.

When the width direction is perpendicular to the traveling direction of the strip 7, the widths of the cathode plate 5 and the anode plate 8 are larger than that of the strip 7 to be polished. When the strip 7 is formed and the traveling direction of the strip 7 is the lengthwise direction, the sum of the lengths of the cathode plate 5 is formed longer than the sum of the lengths of the anode plates 8, and the strip 7 functions as an anode. Although the reason is not clear, the smoothness of the polished surface is improved as a result of increasing the heating time.

As an example of the strip electropolishing apparatus shown in FIG. 1, two cathode placement tanks 13 and 19 having a width of 23 cm, a length of 95 cm and a depth of 15 cm, a width of 23 cm and a length of 30 cm,
Two anode placement tanks 15 and 17 with a depth of 15 cm and a width of 23
cm, a length of 15 cm, and a depth of 15 cm, and three processing liquid discharge tanks 14, 16 and 18 were made of plastic and arranged as a unitary container separated by a partition wall.

In addition, an opening 20 of 15 cm in the width direction of the strip 7 and 3 cm in the thickness direction thereof is provided on the wall surface in contact with each tank so as to smoothly pass the strip 7 to be electrolytically polished. Has been.

Further, a hard lead plate having a thickness of 5 mm, a width of 10 cm and a length of 10 cm is prepared as the anode plate 8, and a copper plate having a thickness of 3 mm, a width of 10 cm and a length of 30 cm is prepared as the cathode plate 5. In each of the electrode placement tanks, one electrode plate of the same polarity was placed above and below the strip 7 at an interval of 3 cm.

With respect to this apparatus, the thickness of the strip 7 is 0.
A copper alloy strip having a width of 18 mm and a width of 10 cm was used as the electrolytic polishing liquid 6, and a commercially available EC56 (manufactured by Depsol Co., Ltd.)
Is contained at a rate of 50 g / l, an aqueous solution of 20 g / l of sulfuric acid and 10 g / l of sodium sulfate is selected, the temperature of the aqueous solution is adjusted to 50 ° C., the current density is 2.0 A / dm ² , and the electrolytic polishing solution is When the electropolishing treatment was carried out with the injection amount of 6 being 12 l / min and the feeding rate of the strip 7 being 3 m / min, the surface smoothness that sufficiently satisfies the acceptance conditions of the subsequent process was obtained, and the reactive current was small. It was suppressed to 2%.

When 4 A is set as the current input setting value, the current value of the strip 7 is 2.4 A, the current efficiency is 60%, and the current efficiency obtained by the conventional method is small. Compared with only 10 to 15%,
Significant improvements were ensured by the practice of the invention.

Similarly, when 6 A is set as the current input set value, the current value of the strip 7 is 4.2 A, the current efficiency is 70%, and the current input set value is 8 A. If you select, the current value of the strip 7 is 5.2A
The current efficiency was 65%.

For comparison, Table 1 shows measured values of current efficiency in the case of using the device of the present invention and the case of using the conventional device.
Also described in.

Note that these measured values are values measured using a commercially available ammeter.

[0044]

[Table 1]

[0045]

According to the practice of the present invention, the isolation of each electrode placement tank is enhanced, and as a result, the reactive current that cannot be avoided in the electropolishing process can be kept to a very small value. By increasing the current efficiency during the work and avoiding the placement of the contacting material with the strip, the abnormal shape of the strip is prevented, which greatly contributes to the improvement of the workability in the electrolytic polishing work.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the electrolysis apparatus of the present invention.

FIG. 2 is an explanatory diagram of a conventional electrolysis device.

FIG. 3 is an explanatory diagram of a conventional electrolysis device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolytic polishing tank 2 Feed roll 3 Feed roll 4 Brush 5 Cathode plate 6 Electropolishing liquid 7 Band material 10 Material supply roll part 11 Electropolishing part 12 Material discharge roll part 13 First cathode placement tank 14 First treatment liquid discharge tank 15 First anode placement tank 16 Second treatment liquid discharge tank 17 Second anode placement tank 18 Third treatment liquid discharge tank 19 Second cathode placement tank 20 Opening 21 Partition wall 24 Bottom 25 Inlet 26 Outlet 27 Electrolytic polishing liquid circulation part 28 upper and lower rolls 41 cathode 42 anode

Claims (6)

[Claims] 1. A strip material electropolishing apparatus in which a material supply roll unit, an electropolishing unit, and a material discharge roll unit are arranged in this order from the strip material introduction direction, wherein the electropolishing unit is first from the strip material introduction direction. The cathode arrangement tank, the first treatment liquid discharge tank, the first anode arrangement tank, the second treatment liquid discharge tank, the second anode arrangement tank, the third treatment liquid discharge tank, the second cathode arrangement tank are arranged in this order, and further, Each of the tanks is partitioned by a partition having an opening for passing a strip material to be subjected to electrolytic polishing treatment, and the first and second cathode placement tanks are separated by a plane connecting the openings, A cathode plate connected to the cathode of the power source is arranged at the position above or below or at the position where it is immersed in the electrolytic polishing liquid, and the first and second anode placement tanks have an opening. Either above or below the plane that connects the two Position, and at a position immersed in the electropolishing liquid, an anode plate connected to the anode of the power source is arranged, and at the bottom of the first and second cathode arrangement tanks and the first and second anode arrangement tanks. Each is provided with an inlet for the electrolytic polishing liquid, and each of the first to third treatment liquid discharge tanks is provided with an outlet for the electrolytic polishing liquid used for the polishing treatment, and The electrolytic polishing treatment liquids individually injected from the above-mentioned inlet toward the first and second cathode placement tanks or the first and second anode placement tanks are the first and second cathode placement tanks, respectively. Alternatively, the strip material electropolishing apparatus is characterized in that the strip material is discharged from a discharge port provided at the bottom of any one of the first to third treatment liquid discharge tanks adjacent to the first and second anode placement tanks. 2. The discharged electropolishing liquid is recovered in the electropolishing liquid circulating part, and the electropolishing liquid is adjusted in the properties of the electropolishing liquid in the electropolishing liquid circulating part before The strip material electropolishing apparatus according to claim 1, wherein the strip material electropolishing apparatus is configured so as to be circulated and supplied to the inlets of the respective cathode placement tanks or the first and second anode placement tanks. 3. Inside the respective tanks of the first and second cathode arranging tanks and the first and second anode arranging tanks, there are provided two partition walls located in front of and behind the traveling direction of the strip. The strip material electropolishing apparatus according to claim 1, wherein one pair of upper and lower rolls are arranged between the opening and the cathode plate or the anode plate in each tank. 4. When the width direction is a direction perpendicular to the traveling direction of the strip, the widths of the cathode plate and the anode plate are formed larger than the width of the strip to be polished. The strip material electropolishing apparatus according to claim 1 or 2, characterized in that. 5. When the traveling direction of the strip is the length direction, the sum of the lengths of the cathode plate is longer than twice the sum of the lengths of the anode plate. The strip material electrolytic polishing apparatus according to any one of claims 1 to 4. 6. The length of the cathode plate is compared with the length of the anode plate when the lengthwise direction is measured with the advancing direction of the strip as its length direction and the adjacent cathode plate and anode plate are measured. 6. The strip electropolishing apparatus according to claim 1, wherein the strip electropolishing apparatus is always formed to be long.