JPS62285454A - Plating treatment equipment - Google Patents

Abstract

PURPOSE:To obtain a small-sized full automatic plating treatment equipment by mounting a magazine housing a large number of semiconductor packages, which are aligned and brought to an adhesive state, a cathode bar, which is positioned in a plating tank and connects a frame to an external power supply when the magazine is placed, an anode bar on a tank bottom and a vertical shielding layer along the side wall of the magazine. CONSTITUTION:A magazine 3, a side wall 13 of which consists of an insulator, is arranged in a tank 2 filled with a plating solution 1, and a large number of frames 11 are housed while sealing bodies 12 are brought into contact. Sections except sections 5 brought into contact with the frames 11 in semiconductors 10 are insulated and coated 6 in cathode bars 4, and two cathode bars 4 are mounted in parallel. A soluble anode 7 is disposed faced oppositely to the magazine 3 on the bottom of the tank 2, and connected to an external power supply. Vertical shielding plates 8, 9 consisting of an insulator having the same size as a frame housing section are fitted to the upper and lower sections of the magazine, and the upper shielding plate 8 takes half size up to the surface of the plating solution from the upper end of the magazine. According to the constitution, plating treatment can be executed at magazine unit, and the frames can be taken in and out freely from the magazine, thus resulting in miniaturization, then equalizing plating-film thickness by a shielding wall.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a plating processing apparatus, and particularly relates to an apparatus for automating and miniaturizing an apparatus for electroplating lead frames of semiconductor devices. It is something.

[Conventional technology]

In general, the external leads of an insulated sealed semiconductor package are coated with a surface coating such as solder, tin, silver, or gold for the purpose of improving corrosion resistance and soldering properties. As methods for this surface treatment, electroplating and molten solder immersion are mainly used, but electroplating has become mainstream for reasons such as product stability and mass productivity.

Next, an example of a conventional electroplating method will be explained with reference to FIGS. 6 to 8.

FIG. 6 is a schematic diagram of a plating bath for electroplating. In FIG. 6, the plating solution 1 is inside the plating tank 2.
is filled, and metal plates 7 as soluble anodes are arranged on both sides of the acid tank 2.

FIG. 7 shows a rank for hanging frames to be plated in a plating tank, and the rack 16 is provided with a number of hooks 15 for hanging frames so that a plurality of lead frames can be processed at once. There is. Further, during the plating process, the lead frame is electrically connected as a cathode via the hook 15. Also, plating is done in plating tank 2.
This is carried out by immersing the hook 16 on which the frame is hooked into the plating tank 2, using the soluble metal plate 7 inside as the anode and the rack 16 side as the cathode, and passing a direct current between the two poles. After being plated for a certain period of time in this way, the racks are taken out of the plating tank and washed with water.

It is dried.

[Problem that the invention seeks to solve]

Conventional plating processing equipment is configured as described above, and therefore the lead frame must be manually attached and removed from the rack.Also, while most semiconductor assembly equipment is automated, conventional equipment is Since this requires manual intervention, there is a problem in that it is not possible to connect and integrate processing equipment including processes before and after the process. In addition, during plating processing, the frame hooked on the rack and the soluble anode need to face each other, so in order to increase the number of plating processes, it is necessary to increase the number of frames hooked on a single rack. There was also the problem that the soluble anode and the plating tank became large.

This invention was made to solve the above-mentioned problems, and its purpose is to obtain a downsized, fully automatic plating processing apparatus.

[Means for solving problems]

A plating processing apparatus according to the present invention includes a magazine that stores a plurality of insulated sealed semiconductor packages arranged in close contact with each other, and a frame that is installed in a plating tank and performs plating by placing the magazine on top of the magazine. It is equipped with a cathode electrode rod for establishing conduction with an external power source, an anode scraping plate provided on the bottom surface of the plating tank, and vertical shielding walls provided above and below the magazine along the side walls.

[Effect]

In this invention, there is provided a magazine for storing a plurality of insulated sealed semiconductor packages arranged in close contact with each other, and the magazine is installed in a plating bath, and by placing the magazine on top of the magazine, conduction is established between the lead frame and an external power source. It is equipped with a cathode electrode rod for removing the plating, an anode electrode plate provided on the bottom of the plating tank, and vertical shielding walls provided along the side walls above and below the magazine, so that plating can be performed using the magazine as a unit. The loading and unloading of lead frames from magazines can be easily automated.
Furthermore, since the magazine system is more compact than the rack system, the entire device can be made smaller. Further, the shielding wall allows the plating film thickness to be made uniform, and quality equivalent to or better than that of the rack method can be obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a plating apparatus according to an embodiment of the present invention, and FIG. 2 schematically shows a state in which a semiconductor device in which a semiconductor element pair body and a lead frame are integrated is housed in a magazine. , 2 is a plating tank filled with electroplating solution 1, 3 is a magazine placed in the plating tank 2 and whose side walls are made of an insulator, and the magazine 3 has 100 frames arranged in sealed packages. are stored in close alignment. Reference numeral 4 denotes cathode electrode rods in which only the portion that contacts the frame of the semiconductor device IO is exposed and the other portions are covered with an insulator, and these are installed in pairs in the plating bath 2 in parallel. . Further, a frame support ring 14 made of an insulator for mounting the frame is provided at the bottom of the magazine 3, and a soluble anode electrode 7 is arranged at the bottom of the plating tank 2 at a position facing the magazine. , continuity with the external power supply is established.

Furthermore, as shown in FIG. 3, the cathode electrode rod 4 is designed to lift up the frame 11 housed in the magazine when a magazine is placed on it, so that the frame 1
1 and the exposed metal portion 5 of the cathode electrode rod 4 come into contact with each other, and conduction between the frame 11 and an external DC power source can be established via the cathode electrode rod 4. In addition, the cathode electrode rod 4 is 1
The other one may be an insulator that only supports the frame, but it is better to use multiple insulators to ensure continuity with the frame.

The above-mentioned plating processing apparatus is the above-mentioned plating tank 2. Plating solution 1.
Magazine 3 containing frame 11. Cathode electrode rod 4
．． Although it is possible to plate the frame by connecting the anode and cathode to an external DC power source and passing a current through the anode and the soluble anode 7, such an apparatus has a large variation in the thickness of the plating film.

Therefore, in this example, in order to make the plating film thickness uniform, upper and lower vertical shielding plates 8.9 made of insulators are installed above and below the magazine and have inner walls of the same dimensions as the frame housing inside the magazine. ing. The longer this vertical shielding plate 8.9 is in the vertical direction, the more effective it is in making the plating film thickness uniform, so it is necessary to determine the dimensions by taking into account the variation in the plating film thickness within the frame and in the upper and lower parts of the frame. The vertical shielding plate 9 on the side has a length from the lower end of the magazine to the soluble anode 7, and the vertical shielding plate 8 on the upper side has a length half the distance from the upper end of the magazine to the plating solution level.

In order to clarify the effect of the vertical shielding plate, FIGS. 4 and 5 show plating film thickness distribution data for frames stored at the ends and center of the magazine.

As can be seen from the figure, without the vertical shielding plate, there is a large difference in the plating film thickness between the magazine ends and the center, and even for a single frame, there is a large difference in plating film thickness between the upper and lower sides. On the other hand, it can be seen that by providing a vertical shielding plate, the difference in thickness of each plating film becomes smaller.

In this way, in this example, the plating process is carried out in units of magazines in which multiple frames are housed in close contact with each other, making it easy to automate the plating process. Compared to the conventional device when processing the same number of frames as in the example, the number is 115 or less, and the device can be made smaller. In addition, vertical shielding plates with inner walls of the same shape as the frame storage area inside the magazine are provided above and below the magazine, which has the effect of suppressing variations in the plating film thickness and improving the reliability of the plating film.

In the above embodiment, vertical shielding plates are provided above and below the magazine, but the magazine itself may be deep enough to include the height of the shielding plate, and the same effect as in the above embodiment can be obtained.

Further, although only the plating process was explained in the above embodiment, it goes without saying that processes such as water washing can also be performed with the frame housed in the magazine.

〔Effect of the invention〕

As described above, according to the plating processing apparatus of the present invention, a plurality of semiconductor devices in which a semiconductor element encapsulation body and a lead frame are integrated are stored in a magazine with the encapsulation packages in close contact with each other, and the magazine is Since the plating process is performed as a unit, the loading and unloading of lead frames from the magazine can be easily automated, eliminating the need for manual loading and unloading of lead frames into racks as in the past.
Moreover, since the magazine system is more compact than the rack system, it has the effect of reducing the size of the entire device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall configuration of a plating apparatus according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing the state of a lead frame stored in a plating magazine of the present invention, and FIG. FIG. 4 is a schematic diagram showing the state in which the plating magazine of the invention is installed on the cathode electrode rod. FIG. 4 is a diagram showing the plating film thickness distribution when vertical shielding plates are provided above and below the magazine of the invention. The figure shows the plating film thickness distribution when vertical shielding plates are not provided above and below the magazine of the present invention, Fig. 6 is a schematic diagram of the plating tank of the conventional plating processing equipment, and Fig. 7
This figure shows a conventional rack for plating processing, and FIG. 8 shows a state in which a frame is hung from the hook of the conventional rack. In the figure, ■ is the electroplating solution, 2 is the plating treatment tank, and 3 is the electroplating solution.
4 is a plating magazine, 4 is a cathode electrode, 5 is an exposed metal part of the cathode electrode, 6 is an insulating part of the cathode electrode, 7 is a soluble anode electrode, 8 is an upper vertical shielding plate of the magazine, 9 is a 1 is a lower vertical shielding plate of the magazine, 10 is a semiconductor device, 1 is a lead frame, 12 is a semiconductor element pair body, 13 is an insulator side wall of a magazine for plating processing, 1
4 is a frame support rod at the bottom of the plating magazine. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A plating tank for storing an electroplating solution, an anode electrode plate provided on the bottom of the plating tank and connected to an external power source, and an anode electrode plate provided above the anode electrode plate in the plating tank and connected to an external power source. a magazine for storing a cathode electrode rod and a plurality of semiconductor packages placed on the cathode electrode rod, aligned and in close contact with each other; A plating processing apparatus comprising: a vertical first shielding wall; and a vertical second shielding wall provided above the magazine sidewall and along the sidewall.