JPS6344300B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a partial plating device used for plating precious metals such as gold and silver onto IC frames.

2. Description of the Related Art Conventional IC frame partial plating devices include those shown in FIGS. 1 and 2, for example. That is, there is a plating box 1 called a "sparger," on which an IC frame 3, which is the object to be plated, is brought into contact with a mask plate 2, which also serves as an upper lid, by using the forward and backward movement of a press plate 4, and the above-mentioned mask plate The plating liquid A is injected in the direction of the arrow in the figure from the plating liquid injection port 5 aimed at the nozzle 6, which is opened in advance in the plating liquid injection port 5. Plating liquid A is applied to the lead pin portion 8 and the support pin 9 of the island portion. Furthermore, nozzle 6
is provided with an anode 10, and the IC frame 3 can be made into a cathode.

However, in such a conventional IC frame partial plating device, although the plating thickness has been reduced in order to save precious metals such as gold and silver, the plating liquid is not applied from the plating liquid injection port 5 of the mask plate 2. Since the plating solution used is used to plate the island portion 7, lead pin portion 8, and support pin 9, there is a limit to the saving of precious metals.

The present invention is based on the fact that in the IC frame, what really requires plating is the lead pin part required for wire bonding, and that conventionally the island part is plated with precious metal to form gold-silicon eutectic and DIE bonded. However, this was done by focusing on the fact that it is possible to use a conductive adhesive on the island part without plating it, and by adding some ingenuity to the shape and structure of the part of the mask plate where the plating liquid is applied. The aim is to further conserve precious metals such as gold and silver.

The details of the present invention will be explained below with reference to the drawings.
FIGS. 3 and 4 show an embodiment of the present invention (first invention). In the following description, parts that are the same as or similar to those of the prior art are designated by the same reference numerals, and redundant explanation will be omitted.

A plating liquid passage 20 is recessed in the mask plate 2. The plating liquid passage 20 is recessed around the island portion 7 of the IC frame 3, leaving a mask portion 21 corresponding to the island portion 7. Reference numeral 22 denotes a partition wall, which is formed at a position and size corresponding to the support pin 9. In the embodiment shown in FIG.
are formed as a pair of left and right plating liquid passages 20, so that the plating liquid passage 20 has a pair of recesses at the front and rear. The plating liquid passage 20 has a position and size corresponding to the lead pin portion 8 of the IC frame 3, and has a supply port 23 for plating liquid A on one side and a discharge port 24 on the other side that penetrates to the back surface of the mask plate 2. It has been done. Reference numeral 25 denotes a plate-shaped anode, which is placed at the bottom of each of the pair of plating liquid passages 20.

Next, the action will be explained.

The plating liquid A injected from the nozzle 6 is supplied to the supply port 2.
The plating liquid enters the plating liquid passage 20 from 3 and fills there, and is discharged and collected into the plating box 1 through the discharge port 24. The IC frame 3 is brought into contact with the mask plate 2 via the pressure plate 4, and the IC
Only the lead pin portion 8 of the frame 3 faces the opening of the plating liquid passage 20 and is exposed, and the island portion 7 and the support pin 9 are respectively shielded by the mask portion 21 and the partition wall 22 and the plating liquid is exposed. Since the passage 20 is not exposed, the plating liquid A is not exposed to the lead pin portion 8 of the IC frame 3 while flowing through the plating liquid passage 20.
The chisel is touched and that part is plated with precious metal.

FIGS. 5A and 5B are diagrams showing other embodiments.

In these embodiments, the plating liquid passage 26 is divided by one partition wall 27 and has an inverted C-shape, and a plate-shaped anode 28 matching the C-shape is attached to the bottom surface of the plating liquid passage 26. A plating fluid supply port 29 and a plating fluid discharge port 3 are provided.
0 [Fig. 5 A], and wire-shaped anodes 31 are arranged in each of the pair of plating liquid passages 20 partitioned by a pair of partition walls 22 [Fig. 5 B], etc. is substantially the same as the previous embodiment. The embodiment shown in Fig. 5A is the plating liquid passage 2.
In the embodiment shown in FIG. 5B, the anode 31 is shaped like a wire to facilitate its arrangement. The other configurations and operations are substantially the same as those in the previous embodiment, so explanations will be omitted.

FIGS. 6 and 7 are diagrams showing an embodiment of the present invention (second invention). The mask plate 2 is provided with a plating liquid injection port 32. This injection port 32 is formed around the island portion 7 of the IC frame 3, leaving a mask portion 33 corresponding to the island portion 7.
The position and size correspond to the lead pin portion 8 of the IC frame 3. Metsuki liquid injection port 3
2 is formed to penetrate from the front surface of the mask plate 2 to the back surface side. The mask part 33 is supported by a nozzle 35 via a support arm 34, and the body part 36 of the mask part 33 is provided with a tapered surface 37 so that the entire shape appears to be an inverted pyramid, and the lower part 38 has a wedge shape. A shaped tapered surface 39 is provided. An anode 40 is arranged at the tip of the nozzle 35.

Next, the action will be explained.

The plating liquid A is sprayed from the nozzle 35 to the lower part 3.
8 and the tapered surface 37 of the body 36, the plating liquid injection port 32 receives almost no liquid resistance.
Then, the exposed lead pin portion 8 of the IC frame 3 is touched and precious metal plating is applied thereto. After colliding with the lead pin portion 8, the plating liquid A is collected into the plating box 1.

Regarding other constituent effects, see the first invention (third invention).
Since it is substantially the same as in FIGS. 4 to 4), the explanation will be omitted.

As explained above, according to the present invention, the configuration is such that a mask portion corresponding to the island portion of the IC frame is left on the mask plate against which the IC frame, which is the object to be plated, is left, and the IC frame is placed around the mask plate. A plating liquid passage corresponding to the lead pin portion is recessed, a plating liquid supply and discharge port is provided in the plating liquid passage, an anode is arranged, and the plating liquid is sprayed from a nozzle [first invention],
In addition, a plating liquid injection port corresponding to the lead pin portion of the IC frame is provided around the mask plate, which corresponds to the island portion of the IC frame, on the mask plate that contacts the IC frame, which is the object to be plated, and an anode is arranged. In the partial plating liquid device for an IC frame, which sprays plating liquid from a nozzle that is attached to the plate, the mask portion is supported by the nozzle via a support arm [second invention].
Precious metal plating such as gold and silver applied to IC frames is mainly applied only to the lead pins of the IC frame, and due to the presence of the mask part mentioned above,
The plating liquid does not come into contact with the island portion of the IC frame, so compared to the conventional method where the island portion was also plated, precious metals can be saved accordingly. When plating only the lead pin portion with precious metal, the plating liquid enters from the supply port, fills the plating liquid passage, and is then quickly recovered from the discharge port [first invention]. Since it is injected toward the injection port and quickly recovered [second invention], high-quality and efficient partial plating can be performed on the parts of the IC frame that require plating, that is, the areas that require plating during wire bonding. This has the advantage that it can be applied to the lead pin portion, which is a required portion.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a conventional example of a partial plating device for an IC frame, FIG. 2 is a partially enlarged perspective view showing the relative positional relationship between the mask plate and the IC frame in FIG. 1, and FIG. 3 is a partial plating device according to the present invention. FIG. 4 is a partially enlarged perspective view showing the relative positional relationship between the mask plate and the IC frame, and FIGS. 5A and 5B are other embodiments of the first invention. FIG. 6 is an enlarged perspective view of the plating liquid passage showing the present invention [Second
FIG. 7 is a schematic cross-sectional view showing one embodiment of the present invention, and FIG. 7 is a partially enlarged perspective view of the mask portion. 1... Metsukibox, 2... Mask board, 3...
...IC frame, 4...Press plate, 5, 32...Metting liquid injection port, 6,35...Nozzle, 7...Island part, 8...Lido pin part, 9...Support pin, 10,25,28 , 31, 40... Anode, 20, 26... Metering liquid passage, 21, 33...
...Mask part, 22, 27...Division wall, 23, 29
... Supply port, 24, 30 ... Discharge port, 34 ... Support arm, 36 ... Body, 37, 39 ... Tapered surface, 38 ... Lower part, A ... Plating liquid.

Claims (1)

[Claims] 1. A mask plate corresponding to the island portion of the IC frame is left on a mask plate which is brought into contact with the IC frame which is the object to be plated, and a plating liquid passage corresponding to the lead pin portion of the IC frame is formed around the mask plate. An anode partial plating device that is recessed, has plating liquid supply and discharge ports in the plating liquid passage, and has an anode arranged thereon, and performs plating by spraying the plating liquid from a nozzle. 2. On the mask plate that contacts the IC frame, which is the object to be plated, leave a mask part corresponding to the island part of the IC frame, and provide a plating liquid spray opening corresponding to the lead pin part of the IC frame around it, and arrange the anode. A partial plating device for an IC frame, wherein the mask part is supported by the nozzle via a support arm.