JPS6114233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frame support member in an apparatus for partially plating a frame for an electronic component such as an IC lead frame.

In recent years, electronic components have become increasingly integrated into ICs and LSIs, and their production is increasing in volume and variety. As the precision has progressed, the prices of precious metals for plating such as gold and silver have soared, and from the perspective of saving precious metals, the conventional method of plating the entire surface of the frame, including the areas where plating was required, has recently changed. There is a rapid shift to partial plating, where plating is applied only to the necessary areas.
For example, when it comes to IC lead frames, they are gradually becoming more compact, ultra-miniaturized, and mass-produced.
In response to changes in IC applications, performance, models, etc., the shape of the parts of the frame that require plating, the pitch (interval between plating), the frame base material, etc. are changing day by day, resulting in an extremely wide variety of products.

Therefore, what is most required when performing this type of partial plating is precision and precision of the plating finish.
The goal is to increase speed and, along with that, be able to respond quickly when changing the plating pattern. However, the conventional nozzle method, in which the frame of the object to be plated is placed on a frame support member with patterned holes corresponding to the areas that require plating, or on a sealing member with patterned holes provided on its upper surface, The nozzle method, in which the plating liquid is jetted from a nozzle provided in a hole in a support member while clamping it from above with a holding member, has the following problems. [B] Conventional nozzles are provided in the hole of the support member with an open periphery for liquid discharge, and as a result, air gets mixed into the jet liquid, creating an air pocket between the part to be plated and the unplated part. Easy to occur. In addition, the liquid flow tends to become splashes, and the loss of flow velocity due to the collision between the jet liquid and the returning liquid that hits the area where plating is required tends to cause uneven plating and poor plating coverage. [B] A nozzle is generally cylindrical with a cross section of 〇-shaped.Therefore, in the center of the 〇-shape, the jet liquid is most powerful and the ion exchange is active, but from there the jet liquid's force decreases concentrically. Therefore, the plating film thickness is non-uniform, being thicker at the center and thinner at the periphery. In particular, when the area that requires plating is □-shaped, the variation in film thickness is even greater.
[C] If the shape, pitch, etc. of the parts of the frame that require plating change in response to changes in IC usage, performance, model, etc., the nozzle method requires changes in nozzle diameter, position, nozzle support member, and pattern. Requires conversion of holed seal member and frame support member.
The costs, adjustment time, etc. associated with this are almost the same as when introducing new equipment. As described above, the conventional nozzle method cannot cope with the recent changes in partial plating of IC lead frames, etc., which are becoming increasingly finer and more mass-consumption, and are in a very unbalanced situation.

The present invention relates to partial plating on IC lead frames and the like, and is an attempt to solve the above-mentioned problems of conventional means. In other words, its purpose is to use it as a means for partial plating on frames for electronic components, which change and become more detailed every day, by eliminating unplated parts due to air pockets, and variations in plating due to flow velocity loss due to liquid splashes and liquid collisions. - Eliminates poor coverage, improves plating finish precision and plating efficiency, makes the film thickness uniform across all areas where plating is required, and allows easy and quick response to pattern changes. , it is an object of the present invention to provide a frame support member in a partial plating device.

The present invention will be explained below by means of illustrated embodiments.
Reference numeral 1 denotes an outer tank which is oblong in shape with an opening at the top, and a constant pressure tank 2 which is also open at the top and is oblong in shape is provided at the center of the lower part of the outer tank. The length of the constant pressure tank 2 is longer than the expected longest length of the IC lead frame 3 to be plated, and the upper ends of the front, rear, right and left side plates 4 serve as supporting end surfaces.

Reference numeral 5 denotes a frame support member, which consists of a lower support plate 6 and a pattern plate 7. The lower support plate 6 has a horizontally elongated shape similar to that of the constant pressure tank 2, and has a hanging edge 8 formed on the lower side thereof to engage with the upper end side of each side plate 4 of the constant pressure tank 2, so as to form a seal over the constant pressure tank 2. It can be placed on.
A shallow groove-shaped recess 9 is formed in the upper center of the lower support plate 6 in the longitudinal direction, and a large number of plating liquid jet holes 10 are formed at equal intervals in the longitudinal direction in the middle part of the recess 9. A large number of groove-shaped liquid discharge parts 1 are formed on both sides of the upper part of the lower plate 6 from the recess 9 to both sides of the lower plate 6 at equal intervals in the longitudinal direction. The plating liquid jet hole 10 has an inner diameter of about 2.5 to 3 mm.
A large number of them are formed at mm intervals. Reference numeral 12 denotes a bolt for attaching the pattern plate 7, which is protruded from the lower support plate 6. The pattern plate 7 is a horizontally long thin plate with the same size as the lower support plate 6, and has a large number of pattern holes 13 formed at equal intervals in the longitudinal direction in the middle part thereof, and has holes 13 formed in the lower part on both sides. A small hole (not shown) is formed to engage with the mounting screw 12 of the plate 6.

Reference numeral 15 denotes an anode, and an insoluble metal plate is provided on the upper surface of the recess 9 of the lower support plate 6, close to both sides of the liquid jet hole 10, and parallel to the longitudinal direction.

Reference numeral 16 denotes a holding member which can be raised and lowered by an air cylinder (not shown), and has a sealing plate 1 on its lower surface.
7 is attached, and a cathode (not shown) is also provided. 18 is a plating liquid main tank, and the plating liquid is sent to the constant pressure tank 2 via a pump 19 and liquid supply pipes 20 and 21. Reference numeral 22 denotes a return pipe for returning the plating liquid stored in the outer tank 1 to the main tank 18.

In the above configuration, the material of the lower support plate 6 is made of plating liquid-resistant synthetic resin or metal, and if it is made of metal, it is coated with electrical insulation. The pattern plate 7 is also made of the same material as described above, but the pattern plate 7 has different pattern holes 13 to accommodate differences in size, shape, position, pitch, etc. of the parts of the lead frame 3 that require plating. Prepare several types in advance. Constant pressure tank 2 of support member 5
In addition to being placed directly on top as described above, a frame plate made of a soft material may be interposed at the upper end of the constant pressure tank 2.
In addition to being a metal plate, the anode 15 may be a plate made of a fine metal mesh. It goes without saying that the inner diameter and spacing of the plating liquid jet holes 10 are not limited to those described above.

In the figure, 14 is a mounting nut.

Next, the state of use of the present invention will be explained with reference to the above-mentioned embodiments. The lower support plate 6 of the support member 5 is placed tightly on the constant pressure tank 2, and the pattern plate 7 is placed on its upper surface and fixed to the mounting bolt 12 with the nut 14. This pattern plate 7 is selected to have pattern holes 13 corresponding to the size, shape, position, pitch, etc. of the portion of the lead frame 3 to be plated that requires plating. Note that the upper surface of the groove-shaped liquid discharge portion 11 is covered by the pattern plate 7. Then, the lead frame 3 is placed on the pattern plate 7 so that the part requiring plating coincides with the pattern hole 13, and the presser member 16 is lowered from above to seal, and then the pump 19 is operated. .

As a result, the plating liquid in the main tank 18 once enters the constant pressure tank 2, the liquid level rises and becomes constant pressure, and flows into each jet hole 10 of the lower support plate 6 of the support member 5 from below. Since each jet hole 10 is a small hole, the liquid is vigorously jetted up into each pattern hole 1 of the pattern plate 7 above it.
3, the parts of the lead frame 3 that require plating are collided with and plated. After that, the Metsuki liquid is
The liquid is immediately discharged from the liquid discharge part 11 to both sides of the lower support plate 6. In this case, since the liquid discharge part 11 is provided near each pattern hole 13, the plating liquid after colliding with the required plating area is distributed evenly and immediately from each part of the pattern hole 13 without stagnation in the pattern hole 13. It is discharged towards the direction. Therefore, the liquid after the collision does not mix with the jet liquid, and air does not mix with the jet liquid, so no air pockets occur. The plating liquid flowing out to the side of the lower support plate 6 once accumulates in the outer tank 1 and then returns to the main tank 18 via the reflux pipe 22, where it is circulated and the plating process is performed.

After that, if there is a change in the size, shape, position, pitch, etc. of the part of the lead frame 3 that requires plating, several types of pattern plates 7 are prepared in advance.
It is sufficient to select one having pattern holes 13 corresponding to the parts requiring plating after the change from among them, and replace it with that one. Thereby, partial plating is performed in the same manner as described above, but if the lead frame 3 is short, it is sufficient to replace it one by one, and if it is long, it may be moved intermittently in the longitudinal direction.

Therefore, the present invention has the following effects.

[a] In the present invention, there is no unplated part or variation in plating, and the plating coverage is good, allowing for precise and efficient plating. That is, in the conventional nozzle method, a nozzle is provided in a hole of a support member with an open periphery for liquid discharge. As a result, air was mixed into the jet liquid, resulting in unplated areas due to air pockets, and flow velocity loss due to splashing of the liquid stream and collision between the jet stream and the discharge stream, resulting in variations in plating and poor plating efficiency. On the other hand, in the present invention, the plating liquid enters each liquid jet hole of the frame support member directly from the constant pressure tank, so there is no mixing of air on the way, and
The liquid flow does not turn into droplets, but instead hits the parts of the frame that need plating in the form of a completely continuous liquid column. Furthermore, after the plating liquid flow collides with the part of the frame that requires plating, it immediately escapes from the liquid drainage part to the side, so there is no flow velocity loss due to collision between the jet flow and the discharge flow, and sufficient ion exchange occurs quickly. As a result, the precision and speed of plating can be greatly improved.

[b] In the present invention, the plating film thickness does not vary in thickness or thinness at any part where plating is required, and uniform plating without variation can be obtained. That is,
If the cross section of a nozzle using the conventional nozzle method is 〇-shaped, and the area where plating is required is □-shaped, a thick plating thickness with a strong liquid flow can be obtained in the center of the nozzle, but the thickness of the plating increases concentrically around the periphery. The thickness is getting thinner. This is because the plating liquid after collision cannot escape and stagnates in the area where plating is required, and the liquid cannot be exchanged sufficiently. On the other hand, in the frame support member of the present invention, liquid drain portions are formed at opposing positions near each pattern hole so that the liquid can be sufficiently drained. Therefore, after the plating liquid collides with the area that requires plating, it is evenly and quickly discharged to the side from any of the four corners, and since there is no area where the liquid accumulates, it is uniformly distributed over the entire area that requires plating. It can be plated to a certain film thickness.

[c] According to the present invention, if the size, shape, position, pitch, etc. of the part of the lead frame that requires plating is changed, it can be easily and quickly handled by simply replacing the pattern plate. In other words, in the conventional nozzle method, when changing the pattern as described above, it is necessary to change the nozzle diameter, position, nozzle support member, and replace the frame support member, masking pattern, etc., which increases the cost and adjustment time. required the same amount of replacement as new equipment.
In contrast, in the present invention, it is only necessary to select a pattern plate corresponding to the changed plating area from among several types of pattern plates prepared in advance and replace it. Just by this exchange, it is possible to perform desired partial plating on different types of lead frames with different sizes, shapes, positions, pitches, etc. of the parts that require plating.

[d] Furthermore, in the present invention, a large number of plating liquid jet holes of small diameter are provided in the frame supporting member. Therefore, the plating liquid from the constant pressure tank collides with the areas requiring plating in the form of a jet jet, and the plating liquid evenly impinges on all parts of the areas requiring plating, making it possible to obtain good plating. In addition, the small-diameter hole requires a small pump capacity, which helps save energy.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention.
The figure is a partially cutaway perspective view of a partial plating device using the frame support member, and FIG. 2 is a partially cutaway enlarged perspective view of the frame support member. Drawing code, 2... constant pressure tank, 3... frame, 5... support member, 6... lower support plate, 7... pattern plate, 9...
Recessed part, 10... plating liquid jet hole, 11... liquid discharge part,
13... Pattern hole, 15... Anode, 16... Pressing member.

Claims (1)

[Claims] 1 In a partial plating device that seals an electronic component frame between a support member and a holding member and plies the plating liquid by jetting the plating liquid from the pattern hole of the support member, the support member 5 is connected to the pattern plate 7 and the support lower plate 6. The pattern plate 7 has pattern holes 1 corresponding to the plating required parts of the frame 3 placed on the top surface.
3 in the longitudinal direction, and are removably attached to the upper surface of the lower support plate 6. The lower support plate 6 has a shape that can be placed on the plating liquid constant pressure tank 2 in a sealed manner, and the A longitudinal recess 9 is formed, and the recess 9
There is a small diameter plating liquid jet hole 10 communicating with the constant pressure tank 2.
are formed in a large number in the longitudinal direction, an anode 15 is provided close to each liquid jet hole 10, and liquid discharge portions 11 to the sides are formed close to the pattern hole 13 on both sides of the upper part of the recess 9. A frame support member in a partial plating device.