JP2000058731A - Electrodeposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of pits in an electrodeposited resist, by providing an electrodepositing liquid spraying nozzle which sprays an electrodepositing liquid upon a material to be electrodeposited in a electrodeposition tank. SOLUTION: A material 180 to be electrodeposited has a product section having an external size formed by punching on a lead frame, a connecting section which is held by a working material composed of a belt-like metallic sheet, and an inlet section 121 and an outlet section 123 to an electrodeposition tank 120. The material 180 is carried in one direction toward the outlet section 123 from the inlet section 121 in the tank 120 by making an electrodepositing liquid 110 to flow out of the inlet and outlet sections 121 and 123. An electrodeposition device 100 is provided with an electrodepositing liquid spraying nozzle 130 which sprays the electrodepositing liquid 110 upon the material 180 in the tank 120. Therefore, the occurrence of pits in an electrodeposited resist 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 electrodeposition processing apparatus for forming an electrodeposition resist on a surface of a belt-shaped material to be electroplated while being conveyed while transporting the material.

[0002]

2. Description of the Related Art Conventionally, a (single-layer) lead frame used as an assembly member of a resin-encapsulated semiconductor device is formed by a pressing method or an etching method. Generally, as shown in FIG. A die pad 711 for mounting a semiconductor element, and an inner lead 71 for connecting to a semiconductor element provided around the die pad 711
2, an outer lead 713 for connecting the inner lead 712 to an external circuit, a dam bar 714 serving as a dam for resin sealing, and a lead frame 710.
A frame (frame) portion 716 for supporting the whole is provided. Then, a lead frame (single-layer lead frame) 7
10 is usually Kovar, 42 alloy (42% nickel-
As shown in FIG. 10B, a semiconductor element 720 is mounted on a die pad 711, and a terminal (pad) 721 of the semiconductor element 720 and an inner After connecting the leading end of the lead 712 with a wire 730 such as gold, the semiconductor device 700 is manufactured by sealing with a resin 740. As described above, since the terminal (pad) 721 of the semiconductor element 720 and the tip of the inner lead 712 are connected by the wire 730 such as gold, silver plating having excellent conductivity and strong bonding force with the wire is applied. In general, partial silver plating is applied to the tip of the inner lead on the semiconductor element mounting side.

Conventionally, this partial silver plating is performed by using a plating apparatus 500 as shown in FIG. 8 and using a masking jig 520 except for a region to be plated of a continuous lead frame 510 having several sets of lead frames. A jig plating method of a sparger type in which plating is performed while applying a plating solution 580 ejected from a nozzle 540 to an area to be plated is mainly performed. With this jig plating method, a jig is required for each type of lead frame, and it takes a long time to manufacture the jig, and wear and fatigue occur as the jig is used. Problems in terms of cost and cost. In consideration of plating quality, positioning is performed by positioning pins and plating is performed after pinching and holding a single lead frame with upper and lower jigs. Therefore, plating quality such as plating position accuracy and plating thickness uniformity is improved. It is susceptible to the accuracy of the manufactured jig and the accuracy of the mounting. In addition, there is a problem that plating easily deposits on the side and back surfaces of the lead frame, which does not originally require plating, and requires a high level of empirical technology for adjustment. Furthermore,
Due to the increase in the number of input / output terminals of semiconductor devices due to advances in semiconductor processes and the narrowing of the inner leads due to the miniaturization of package sizes, the dimensional accuracy of plated parts has become even more severe, and dimensional accuracy is also being addressed. It's getting harder.

For this reason, a jig is not required, and it is possible to cope with an increase in the number of terminals of a semiconductor element and a reduction in an inner lead portion. Using a photosensitive electrodeposition resist having resistance to a plating solution as shown in the drawing, only a predetermined area of a lead frame of one frame (also referred to as a single unit) having a set of several lead frames is used as a plating solution. A silver plating method of a lead frame, which is masked and plated in an exposed state, has also been adopted. A partial silver plating method using the electrodeposition resist will be briefly described with reference to FIG. FIG. 7 shows a cross section of a part (characteristic portion) of a lead frame for explaining the partial silver plating method using the electrodeposition resist. First, the entire lead frame 410 is electrolytically degreased, pickled, and chemically polished (FIG. 7A), and then the entire surface of the lead frame 410 is subjected to copper strike plating 430 as base plating (FIG. 7).
(B)) Then, an electrodeposition resist 420 is formed on the entire surface. (FIG. 7C) Next, using a predetermined pattern plate 450, a predetermined portion (a tip portion of the die pad 411 and the inner lead 412) is exposed to ultraviolet light (exposure light) 460 to cure only the exposed portion ( Next, a developing process is performed to remove the electrodeposited resist 420 in the unexposed portion, thereby exposing the silver plated portion 440A (FIG. 7E).
Next, after cleaning the exposed plating part 440A,
The entire lead frame is immersed in a silver plating solution and plated with a predetermined current density and time while stirring.
A silver plating (film) 440 having a desired film thickness is obtained on 40A.
(FIG. 7 (f)) Thereafter, the electrodeposited resist 420 is peeled off by a peeling liquid to obtain a lead frame 410A having a silver plating (film) 440 only in a predetermined region. (FIG. 7 (g))

To form an electrodeposited resist in a silver plating method for a lead frame using the electrodeposited resist shown in FIG. 7, a strip-shaped thin metal plate material is perforated to form an outer shape, and a product portion (lead frame portion) is formed at a connecting portion. In recent years, a method of performing electrodeposition in a belt-like state holding ()) has been adopted from the viewpoint of processability and workability. In this method, as shown in FIG. 6, electrodeposition is performed in an electrodeposition bath 320 while the surface of the material to be electrodeposited 310 is kept in a belt shape while being conveyed in a substantially horizontal direction. However, in this method, the material to be electrodeposited 31
0 is conveyed in the horizontal direction, bubbles generated on the surface of the material 310 to be electrodeposited during electrodeposition tend to stay on the lower surface, and pits are formed on the electrodeposition resist formed by electrodeposition due to the bubbles. (Pinholes) often occur, which has been a problem. In addition, when the material to be electrodeposited 310 enters and exits the electrodeposition bath 320, a liquid leaks. Therefore, one end of the leaked electrodeposition liquid 313 is collected in an electrodeposition liquid storage 325, and the collected electrodeposition liquid 313 is filtered by a pump 340. Discharge piping 34 via 345
The electrodeposition liquid circulation system is circulated again from step 9 and returned to the electrodeposition tank 320. However, since the amount of liquid to be circulated is large, bubbles cannot be completely removed during the circulation, causing bubbles in the circulation path. The occurrence of pits (pinholes) in the electrodeposition resist is also observed, which is a problem. In the case of the apparatus shown in FIG. 6, air bubbles generated when the material to be electrodeposited may be directly attached to the surface of the material to be electrodeposited.

In the case of the method shown in FIG. 6, while being held by a strip-shaped (tube-shaped) metal sheet material, a noble metal plating such as silver plating is continuously applied as shown in FIG. It has also been attempted to do so. In FIG. 9, reference numeral 611 denotes a hoop-shaped processing material holding a large number of externally processed products provided with an electrodeposition resist at a connection portion, 620 denotes a precious metal plating tank, 613 a precious metal plating solution, and 660 denotes a transport fixing. 670 is an electrode. Incidentally, FIG.
It is sectional drawing in D1-D2 of (a).

[0007]

As described above, when a noble metal plating is performed on a lead frame, a photosensitive electrodeposition resist having resistance to a plating solution is used as a plating mask without using a jig. Although plating methods have been adopted, pits (pinholes) are generated in the electrodeposited electrodeposited resist, and quality measures have been demanded in terms of productivity and mass productivity. The present invention is obtained in such a situation by punching a band-shaped metal sheet material and processing the outer shape,
In addition, plating of an electrodeposited resist for plating only a predetermined area on a lead frame externally processed product in which one or a plurality of product parts are held on the strip-shaped metal sheet material via a connecting part. To make a mask,
An electrodeposition processing apparatus for use in a process of electrodepositing a photosensitive electrodeposition resist, which is intended to provide an electrodeposition processing apparatus capable of suppressing generation of pits (pinholes) in the electrodeposited electrodeposition resist. Things.

[0008]

According to the present invention, there is provided an electrodeposition processing apparatus, comprising: transporting a belt-shaped material to be electrodeposited in one direction in an electrodeposition tank; An electrodeposition processing apparatus for electrodepositing a resist, wherein the material to be electrodeposited has an inlet to the electrodeposition tank and an outlet from the electrodeposition tank below the electrodeposition liquid surface of the electrodeposition tank. Are provided at the front side and the rear side in the traveling direction of the electrodeposited material of the electrodeposition tank, respectively, and the electrodeposition liquid is caused to flow out from the inlet portion and the outlet portion. Supported before and after the electrodeposition tank in the direction, not supported in the electrodeposition tank, the electrodeposited material is in contact with only the electrodeposition liquid in the electrodeposition tank, and the electrodeposited material is placed in the electrodeposition tank. A plurality of nozzles for spraying an electrodeposition liquid on the material to be electrodeposited in the electrodeposition tank are provided in one direction from the inlet to the outlet. And it is characterized in and.
Here, the band-shaped electrodeposited material is a thin plate-like member made of metal or resin and connected in a belt-like shape. Including those held by The electrodeposited material is in a state where at least the surface has conductivity. As a specific example of the material to be electrodeposited, a band-shaped metal plate material such as a lead frame is obtained by perforating and forming an outer shape, and the band-shaped metal plate material has one or more product parts via a connecting portion. A plurality of externally processed products or a laminated sheet of resin and metal for a printed wiring board may be used.

In the above, the angle at which the electrodeposition liquid spray nozzle sprays the electrodeposition liquid is in the range of 45 ° to 90 ° with respect to the direction of travel of the material to be electrodeposited. . In the above, the electrodeposition liquid spray nozzle is a slit nozzle. Further, in the above, in order to cause bubbles in the electrodeposition liquid to flow out from the upper part of the liquid surface of the electrodeposition bath, the electrode overflows on the upper surface side of the electrodeposition liquid. Further, in the above, in order to allow the electrodeposition liquid to flow out of the electrodeposition bath from the inlet portion and the outlet portion, or to make the flow of the electrodeposition solution in the electrodeposition bath from bottom to top, An electrodeposition liquid supply unit for supplying an electrodeposition liquid from the lower side of the electrodeposition tank is provided to allow bubbles to flow out from the upper part of the liquid surface of the electrodeposition tank, and the electrodeposition liquid discharged from the inlet and the outlet. Alternatively, a flow receiver is provided for collecting or circulating and using the electrodeposition liquid overflowing on the upper surface side of the electrodeposition liquid. Further, in the above, the electrodeposition liquid supplied to the nozzle is used by circulating the electrodeposition liquid by overflowing from the upper surface side of the electrodeposition liquid, or by collecting or circulating the electrodeposition liquid flowing out from the inlet and the outlet. Separate from the system,
It is characterized in that the electrodeposition liquid inside the electrodeposition tank is circulated and used. Further, in the above, a diaphragm for preventing the passage of bubbles is provided between the electrode and the electrodeposited material. Further, in the above, the material to be electrodeposited is obtained by forming a hole in a band-shaped metal plate material, and one or more product parts are held in the band-shaped metal plate material via a connecting portion. Characterized in that the material to be electrodeposited is a lead frame as a product part.

[0010]

According to the electrodeposition processing apparatus of the present invention, an electrodeposition resist is electrodeposited on the surface of a belt-like material while the belt-like material is being conveyed. Pits (pinholes) in the electrodeposition resist are less likely to occur, and an efficient electrodeposition processing apparatus can be provided in terms of workability. In particular, the material to be electrodeposited is obtained by punching a strip-shaped sheet metal material and processing the outer shape, and the product portion is connected to the strip-shaped sheet metal material via a connecting portion.
In the case of an externally processed lead frame having one or a plurality of pieces, the electrodeposition processing apparatus of the present invention is effective, and this apparatus is used to perform plating of an electrodeposition resist for plating only a predetermined area. Since masks can be manufactured in terms of quality, high efficiency can be achieved in terms of workability, and mass production can be expected. Specifically, the entrance of the material to be electrodeposited into the electrodeposition tank and the exit from the electrodeposition tank are positioned at positions below the electrodeposition liquid level of the electrodeposition tank, respectively. Provided on the front side, the rear side in the traveling direction of the electrodeposition material, and, at the inlet portion, the outlet portion, to allow the electrodeposition liquid to flow out, supporting the electrodeposited material before and after the electrodeposition tank in the traveling direction, Not supported in the electrodeposition tank, the material to be electrodeposited is in contact with only the electrodeposition liquid in the electrodeposition tank, and the material to be electrodeposited is transported in one direction from the inlet to the outlet in the electrodeposition tank. This is achieved by providing a plurality of electrodeposition liquid spray nozzles for spraying the electrodeposition liquid on the material to be electrodeposited in the electrodeposition bath. That is, in the electrodeposition tank, the material to be electrodeposited is brought into contact with only the electrodeposition liquid in the electrodeposition tank, and the electrodeposited material is transported in one direction from the inlet to the outlet in the electrodeposition tank. As a result, it is possible to minimize the adhesion of dirt to the surface of the material to be electrodeposited, the adhesion of dirt to the electrodeposited surface during and after electrodeposition, and the damage to the electrodeposited film surface due to contact. And Also, by providing a plurality of electrodeposition liquid spray nozzles for spraying the electrodeposition liquid to the material to be electrodeposited in the electrodeposition tank, circulation of the electrodeposition liquid and entry and exit of the electrodeposition material into and from the electrodeposition tank are performed. It is possible to reduce the generation of pits (pinholes) caused by bubbles generated at the time or bubbles on the surface of the electrodeposited material generated during the electrodeposition. In particular, the angle at which the electrodeposition liquid spray nozzle sprays the electrodeposition liquid is 45 °
When the angle is within the range of 90 °, it is possible to effectively prevent bubbles from adhering to the material to be electrodeposited. Further, since the electrodeposition liquid is caused to flow out from the inlet and the outlet, it is possible to reduce the flow of bubbles into the electrodeposition tank due to the entry and exit of the material to be electrodeposited into and from the electrodeposition tank. And

Further, an electrodeposition liquid supply section for supplying an electrodeposition liquid from the lower side of the electrodeposition tank is provided, and the electrodeposition liquid is caused to overflow on the upper surface side of the electrodeposition liquid. The flow of the liquid is set to be from the bottom to the top, and bubbles in the electrodeposition liquid can be positively flown from the upper part of the liquid surface of the electrodeposition tank to the outside. This reduces the stagnation of the electrodeposition liquid on the upper and lower surfaces of the material to be electrodeposited,
Attachment of gas (bubbles) and the like generated near the material to be electrodeposited during electrodeposition to the material to be electrodeposited can be prevented as much as possible.

The electrodeposition liquid supplied to the nozzle is used by circulating it by overflowing from the upper surface side of the electrodeposition liquid.
Or, separate from the system that collects or circulates the electrodeposition liquid flowing out from the inlet and outlet, and circulates and uses the electrodeposition liquid inside the electrodeposition tank, so that the whole can be easily controlled. And

[0013] In the electrodeposition apparatus of the present invention, the material to be electrodeposited is obtained by punching a band-shaped metal plate material and forming an outer shape, and the product portion is connected to the band-shaped metal plate material via a connecting portion. The present invention can also be applied to one or more externally processed products held. This is particularly effective when an externally processed product having a lead frame as a product portion is used as a material to be electrodeposited.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electrodeposition apparatus according to the present invention will be described with reference to the drawings. FIG. 1A is a schematic cross-sectional view of a first example of an embodiment of an electrodeposition processing apparatus according to the present invention, and FIG. 1B is a cross-sectional view taken along line A1-A2 in FIG. FIG. 2 (a) is a schematic diagram showing the path of the electrodeposition liquid for easy understanding, FIG. 2 (a) is a schematic sectional view of a second example of the embodiment of the electrodeposition processing apparatus of the present invention, and FIG. (A)
3 (a), 3 (b) and 3 (b) are schematic views showing the cross section along B1-B2 of FIG.
4B is a simplified cross-sectional view of a modification of the first example, and FIG. 4A is a diagram for explaining an angle θ at which nozzles spray the electrodeposition liquid, and FIG. FIG. 4C is a view of a flat nozzle, FIG. 4C is a view of a slit nozzle, and FIG. 5 is a view showing a state of an electrodeposited material which has been drilled and processed with a product portion as a lead frame. 1 to 5, 10
Reference numerals 0 and 105 denote an electrodeposition processing apparatus, 110 denotes an electrodeposition liquid, 120 denotes an electrodeposition tank, 121 denotes an entrance, 121A denotes a flow receiver,
3 is an outlet, 123A is a flow receiver, 125 is an overflow receiver, 130 is an electrodeposition liquid spray nozzle, 131 is an outlet, 150 is an electrodeposition liquid supply unit, 151 is an electrodeposition liquid storage, 152 is a pump, and 153 is a filter. 154 is a pipe, 157 is a current plate, 160 is an electrode, 172 is a pump,
173 is a filter, 175 is a pipe, 177 is a control valve, and 180 is a material to be electrodeposited. In addition, in the electrodeposition tank in FIG.
The arrow of the electrodeposition liquid supply unit indicates the direction of the flow of the electrodeposition liquid.

First, a first example will be described. The electrodeposition processing apparatus 100 of the first example shown in FIG.
This is an electrodeposition processing apparatus for electrodepositing a photosensitive electrodeposition resist on the surface while the belt 80 is conveyed in one direction while the surface is substantially vertical.
The electrodeposited material 180 has a product part of a lead frame, a large number of product parts, perforated outer shape processing, and a connecting part held by a processing material made of a band-shaped metal thin plate. Then, the entrance portion 121 of the electrodeposited material 180 into the electrodeposition tank 120 and the exit portion 123 from the electrodeposition tank 120 are connected to the electrodeposition tank 120.
At a position below the electrodeposition liquid level of
Provided on the front side and the rear side in the traveling direction of the electrodeposited material 180, and
The electrodeposition liquid 110 is caused to flow out from the inlet part 121 and the outlet part 123, and supports the material to be electrodeposited 180 before and after the electrodeposition tank 120 in the traveling direction, but does not support the electrodeposition material inside the electrodeposition tank 120. A method in which the electrodeposited material 180 is brought into contact with only the electrodeposition liquid 110 in the electrodeposition tank 120 and the electrodeposited material 180 is transported in one direction from the inlet 121 to the outlet 123 in the electrodeposition tank 120. It is. Further, the electrodeposition processing apparatus 100 of the first example includes a plurality of electrodeposition liquid spray nozzles 1 for spraying the electrodeposition liquid 110 on the material 180 to be electrodeposited in the electrodeposition tank 120.
30 are provided. In addition, the entrance part 121, the exit part 123
To drain the electrodeposition solution out of the electrodeposition bath from
The flow of the electrodeposition liquid 110 in the electrodeposition tank 120 is set from bottom to top, and the bubbles in the electrodeposition liquid 110 flow from the lower side of the electrodeposition tank 120 in order to flow out from above the liquid level of the electrodeposition tank 120. Electrodeposition liquid 11
And a flow receiver 121A, 12 for collecting or circulating and using the electrodeposition liquid 110 flowing out from the inlet 121 and the outlet 123.
3A and an overflow receiver 125 for collecting or circulating and using the electrodeposition liquid overflowing on the upper surface side of the electrodeposition liquid in the electrodeposition tank 120.

As shown by the dotted arrows in FIG. 1A, the overflow receiver 125, the flow receivers 121A and 123A.
Is passed through a flow path (not shown) such as a pipe to the electrodeposition storage 151. Further, the electrodeposition liquid in the electrodeposition liquid storage 151 is sent to the lower side of the electrodeposition tank 120 via the filter 153 by the pump 152, and the electrodeposition liquid is vertically transferred from the bottom through the rectifying plate 157. This is for supplying liquid. The filter 153 removes bubbles in the electrodeposition liquid. The current plate 157 allows the flow of the electrodeposition liquid to be evenly dispersed throughout the electrodeposition tank by passing the electrodeposition liquid through a vertically opened hole, and the flow of the electrodeposition liquid is combined with the flow of the liquid by overflow. , From the bottom to the top in the electrodeposition tank. Here, the electrodeposition tank 1
The liquid overflowing from the surface of the electrodeposition liquid 20 and the electrodeposition liquid flowing out from the entrance 121 and the exit 123 of the electrodeposition tank 120 are collected, circulated again and sent to the electrodeposition tank 120, but collected. The entire structure for feeding the electrodeposition liquid upward from the lower side of the electrodeposition tank 120 is referred to as an electrodeposition liquid supply unit 150. Replenishment or replacement of a new predetermined electrodeposition solution is performed as necessary.

The overflow receiver 125 is provided for the electrodeposition tank 12.
The electrodeposition liquid is caused to flow when the liquid level of 0 reaches a predetermined height, and a hole such as a slit may be provided in the wall of the electrodeposition tank 120 to flow the electrodeposition liquid. This flow causes bubbles in the electrodeposition liquid to flow into the overflow receiver 125, and a minimum necessary flow is preferable.

A flow receiver 121A is provided at an entrance 121 of the electrodeposited material 180 to the electrodeposition tank 120, and a flow receiver 123A is provided at an outlet 123 from the electrodeposition tank 120, from which the electrodeposition liquid flows out. As such, the electrodeposition liquid supply unit 150 supplies the electrodeposition liquid. This prevents bubbles from flowing into the electrodeposition tank 120 as the material to be electrodeposited 180 enters and leaves the electrodeposition tank 120.

In this embodiment, air bubbles are generated on the surface of the material to be electrodeposited 180 and the surface of the electrode 160 during electrodeposition.
In order to prevent the bubbles generated in 60 from adhering to the electrodeposited material 180, a diaphragm for preventing the passage of bubbles is provided between the electrode 160 and the electrodeposited material 180 so as to surround the electrode 160. It is not shown in FIG. 1 for clarity. still,
The electrodeposited material 180 and the electrode 160 or the electrodeposited material 18
It is preferable to include a distance adjustment unit (not shown) that can make the distance between the zero and the diaphragm (not shown) variable. The structure includes a motor, a belt, a driving support, and the like, in which the positions of the electrode 160 and the partition can be independently changed by rotating the motor to drive the driving support. However, it need not be limited to this. Thereby, it is possible to cope with various electrodeposition conditions.

As shown in FIG. 1A, in the electrodeposition processing apparatus 100, the electrodeposition liquid spray nozzles 130 are provided on both front and back surfaces of the material 180 to be electrodeposited. The electrodeposition liquid sprayed from the electrodeposition liquid spray nozzle 130 directly or the electrodeposition liquid in the vicinity of the electrodeposition material 180 where the flow is generated releases bubbles attached to the electrodeposition material 180, and the electrodeposition liquid is sprayed. Prevents the generation of pinholes due to bubbles in the film. This, together with the flow of the electrodeposition liquid 110 in the electrodeposition tank 120 from below to above, prevents the adhesion of bubbles to the material 180 to be electrodeposited. FIG.
(A) As shown in (a), here, the angle θ between the traveling direction of the material to be electrodeposited 180 (thick dotted arrow) and the direction of the sprayed electrodeposition liquid (thick solid line arrow) is defined as an electrodeposition liquid. Spray nozzle 1
The angle at which the electrodeposition liquid is sprayed is 30. For example, in the case of FIGS. 4A and 4B, θ is 90 °. The angle θ is preferably in the range of 45 ° to 90 °. As a nozzle,
A flat nozzle as shown in FIG.
A slit nozzle as shown in (c) is used. still,
FIGS. 4 (b) and 4 (b) are views from the side of the electrodeposition liquid outlet, and FIGS. 4 (b) and (b) are views from the side of the electrodeposition liquid outlet of FIGS. 4 (c) and 4 (b). (C) (b). FIG. 1 (a)
As shown in FIG. 1B, the nozzle 130 collects and circulates an overflow from the upper surface of the electrodeposition liquid in the electrodeposition tank 120 and an outflow when the material to be electrodeposited 180 enters and exits, as shown in FIG. Liquid supply unit 150 (FIG. 1)
(Shown in FIG. 1 (a)), which circulates as shown in FIG. 1 (b) and applies pressure by a pump 172 or the like to blow out the electrodeposition liquid from the opening. In this example, the electrode 160
The electrodeposition liquid spraying nozzles 130 are arranged before and after the electrodeposition material 180 in the traveling direction, respectively. The electrodeposition liquid spray nozzle 130 on the outlet 123 side is for removing bubbles adhered to the surface of the material 180, and for removing bubbles in a portion that has become a pinhole due to bubbles when forming an electrodeposition film. is there.

As the electrodeposition solution 110, for example, a small amount of a photosensitizer is added to an acrylic unsaturated compound having a carboxyl group, which is dissolved in an acrylic monomer or styrene and neutralized with an organic amine. And the like. However, the electrodeposition liquid is not limited to the acrylic type, and may be, for example, a polyolefin-based or polybutadiene-based electrodeposition solution. In addition, examples of the photosensitizer include benzoin ether. The electrodeposition resist film may be either an anion deposition type or a cation deposition type. The photosensitive electrodeposition resist is not particularly limited to a positive type or a negative type. The electrodeposition resist is deposited on the cathode in the case of the cation type, and is deposited on the anode in the case of the anion type. Therefore, the polarity on the side of the object to be electrodeposited (lead frame outer processed product) is determined according to the type. In addition, as the lead frame material, 42 alloy (42% nickel-iron alloy), Kovar, various copper alloys can be applied, and expensive precious metal plating such as silver plating, palladium plating, and palladium alloy plating can be efficiently used. It can be attached only to the desired part.

When the material to be electrodeposited 180 is a lead frame as a product part, for example, as shown in FIG. As shown in FIG. 10A, a single lead frame 210 shown in FIG. 2B (also referred to as a single unit) is formed by connecting and holding a single lead frame 210 with a plurality of frames or connecting portions. 210A is converted into a band-shaped processing material 20.
5 while being held by the connecting portion 220, a plurality of perforations are formed.

As a modified example of the electrodeposition processing apparatus of the first example shown in FIG. 1, as shown in FIG. Electrodes 160 are provided on the front and back, respectively, and electrodeposition liquid spray nozzles 130 are provided before and after in the advancing direction of the electrodeposited material 180 of each electrode, or as shown in FIG. In one example, a configuration in which the nozzle above the electrodeposited material 180 is removed is given.

Next, a second example will be described. The electrodeposition processing apparatus 105 of the second example shown in FIG. 2 is different from the first example shown in FIG. 1 in that the material to be electrodeposited 180 is conveyed in a state where its surface is substantially horizontal, and In this state, a photosensitive electrodeposition resist is electrodeposited on the surface. The supply of the electrodeposition liquid and the flow are basically the same as those in the first example, but by performing the electrodeposition while transporting the material 180 to be electrodeposited while keeping its surface almost horizontal. First
The electrodeposited material 1 of the present example is compared with both surfaces of the electrodeposited material 180 of the example.
Air bubbles are difficult to remove on the lower surface of 80.

[0025]

As described above, the present invention relates to an electrodeposition processing apparatus for forming an electrodeposited resist on the surface of a belt-like material to be electroplated while transporting the same. In addition, it is possible to provide an electrodeposition processing apparatus with less occurrence of pits (pinholes) in the electrodeposition resist and having good workability. In particular, a lead frame in which the material to be electrodeposited is obtained by perforating a strip-shaped metal sheet material, and one or more product parts are held in the strip-shaped metal sheet material via a connecting portion. In the case of an externally processed product, the electrodeposition processing apparatus of the present invention is effective, and this apparatus makes it possible to produce a plating mask composed of an electrodeposition resist for plating only a predetermined area in quality. In addition, high efficiency can be achieved in terms of workability, and mass production can be expected. In plating lead frames using electrodeposition resist, there is no need to worry about plating leakage as in the jig plating method.
It is possible to plate expensive noble metals such as silver, and furthermore, it is possible to cope with miniaturization of the lead frame, that is, narrower pitch of the inner leads, so that the electrodeposition processing apparatus of the present invention can be used for mass production of lead frames. It is also possible to deal with miniaturization.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first example of an embodiment of an electrodeposition processing apparatus according to the present invention.

FIG. 2 is a schematic view showing a second example of the embodiment of the electrodeposition apparatus of the present invention.

FIG. 3 is a simplified diagram showing a modification of the first embodiment of the electrodeposition processing apparatus according to the present invention.

FIG. 4 shows the spray angle θ of the electrodeposition liquid spray nozzle.
For explaining the electrodeposition liquid spray nozzle

FIG. 5 is a diagram showing a state of an electrodeposited material which has been drilled and contoured by using a product part as a lead frame.

FIG. 6 is a diagram of a conventional electrodeposition processing apparatus for coating an electrodeposition resist.

FIG. 7 is a process chart for explaining a plating process using a conventional electrodeposition resist film.

FIG. 8 is a schematic view of a masking type partial plating apparatus using a jig.

FIG. 9 is a schematic diagram for explaining a noble metal plating method for a strip-shaped plate whose outer shape is processed using an electrodeposition resist film as a mask.

FIG. 10 is a diagram illustrating a lead frame and a semiconductor device;

[Explanation of symbols]

100, 105 Electrodeposition processing apparatus 110 Electrodeposition liquid 120 Electrodeposition tank 121 Inlet 121A Flow receiver 123 Exit 123A Flow receiver 125 Overflow receiver 130 Electrodeposition liquid spray nozzle 131 Blow-out part 150 Electrodeposit liquid supply part 151 Electrodeposit liquid storage 152 Pump 153 Filter 154 Piping 157 Rectifying plate 160 Electrode 172 Pump 173 Filter 175 Piping 177 Control valve 180 Electrodeposited material 200 Electrodeposited material 205 Processing material 210 One lead frame 210A One frame of lead frame (one station) 220 Connection part 310 Material to be electrodeposited 313 Electrodeposition liquid 313A Supplementary charging liquid 320 Electrodeposition tank 323 Overflow receiver 325 Electrodeposition liquid storage 340 Pump 345 Filter 347 Pipe 349 Discharge pipe 350 Electrodeposition liquid circulation part 41 0 Lead frame 410A Silver-plated lead frame 411 Die pad 412 Inner lead 412A Side (edge) 420 Electrodeposited resist film 430 Copper strike plating 440 Silver plating (film) 440A Plating portion 450 Pattern plate 460 Ultraviolet (exposure light) 500 plating Apparatus 510 Lead frame 520 Masking jig 530 Pressing jig 530A Pressing material 530B Elastic material 540 Nozzle 550 Constant current source 560 Anode electrode 570 Cathode electrode 611 Electrodeposited material 613 Precious metal plating solution 620 Precious metal plating tank 660 Roll for transport and fixing 670 Electrode 700 Semiconductor device 710 Lead frame 711 Die pad 712 Inner lead 713 Outer lead 714 Dam bar 715 Suspended lead 716 Frame part 20 semiconductor device 721 terminals (pads) 730 wire 740 resin

Claims (9)

[Claims] 1. An electrodeposition treatment apparatus for forming an electrodeposition resist on a surface of a belt-shaped material to be electrodeposited on a surface thereof while transporting the belt-shaped material in one direction in an electrodeposition tank. The electrodeposited material is placed at the entrance to the electrodeposition tank and the outlet from the electrodeposition tank at a position below the electrodeposition liquid level of the electrodeposition tank, respectively. Provided on the front side, the rear side in the advancing direction of the material, and allows the electrodeposition liquid to flow out from the inlet portion and the outlet portion,
The material to be electrodeposited is supported before and after the electrodeposition tank in the traveling direction, but not supported in the electrodeposition tank. The electrodeposition material is transported in one direction from the inlet to the outlet in the electrodeposition tank, and a plurality of electrodeposition liquid spray nozzles for spraying the electrodeposition liquid on the material to be electrodeposited in the electrodeposition tank are provided. An electrodeposition processing apparatus characterized by the above-mentioned. 2. The electrode according to claim 1, wherein the angle of spraying the electrodeposition liquid with the electrodeposition liquid spray nozzle is in the range of 45 ° to 90 ° with respect to the traveling direction of the material to be electrodeposited. Dressing equipment. 3. The electrodeposition processing apparatus according to claim 1, wherein the nozzle for spraying the electrodeposition liquid is a slit nozzle. 4. The electrodeposition apparatus according to claim 1, wherein bubbles in the electrodeposition solution are caused to overflow from the upper surface side of the electrodeposition solution in order to flow out from above the liquid surface of the electrodeposition bath. Dressing equipment. 5. The method according to claim 1, wherein the flow of the electrodeposition liquid from the inlet or the outlet to the outside of the electrodeposition tank or the flow of the electrodeposition liquid in the electrodeposition tank is changed from bottom to top. And an electrodeposition liquid supply unit for supplying the electrodeposition liquid from the lower side of the electrodeposition tank in order to cause bubbles in the electrodeposition liquid to flow from the upper part of the liquid surface of the electrodeposition tank, and an inlet part and an outlet part. The electrodeposition liquid spilled from
An electrodeposition processing apparatus comprising a flow receiver for collecting or circulating and using the electrodeposition liquid overflowing on the upper surface side of the electrodeposition liquid. 6. The electrodeposition liquid supplied to the nozzle according to claim 4 or 5, wherein the electrodeposition liquid overflows from the upper surface side of the electrodeposition liquid and is circulated for use, or the electrodeposition liquid discharged from an inlet or an outlet. An electrodeposition treatment apparatus characterized in that the electrodeposition liquid is separated from the system for recovering or circulating, and the electrodeposition liquid inside the electrodeposition tank is circulated and used. 7. An electrodeposition processing apparatus according to claim 1, wherein a diaphragm for preventing air bubble passage is provided between the electrode and the material to be electrodeposited. 8. The material for electrodeposition according to claim 1, wherein the material to be electrodeposited is obtained by perforating a strip-shaped metal plate material and forming a product portion on the strip-shaped metal plate material via a connecting portion. An electrodeposition processing apparatus characterized by being one or more externally processed products held. 9. An electrodeposition processing apparatus according to claim 8, wherein the material to be electrodeposited is a lead frame as a product part.