JPS5932261B2 - Injection deburring method and device that reduce compressed air consumption - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection deburring method and apparatus that reduce compressed air consumption.

Molded products that have sharp edges in contact with metal, e.g.
As shown in FIG. 2, the unfinished semiconductor container C shown in FIG.
For example, mold a package B of synthetic Shugekuni, in which an electronic element is built in between the legs apb of the lead frame A punched out, cut it into pieces one by one, bend both legs atb,
The product shown in Fig. 1 is semiconductor container C, but the second
When package B is molded as shown in the figure, the contact area between package B and lead frame A is unavoidably exposed to flash or flash d of synthetic resin, which is the material of package B.
These must be removed because they interfere with the adhesion of solder or electroplating in subsequent steps.

There are methods to remove this flash, such as the platter method and the blast method, but due to the high degree of adhesion of the synthetic resin of package B, the flash cannot be completely removed by the black method, and the blast method is Although it can be completely removed, it requires a large amount of compressed air and has the drawback of increasing equipment and power costs for the compressor.

The applicant conducted experiments in combination with various cleaning methods as a way to reduce the amount of compressed air, and found that if electrolytic stripping was applied in advance, the amount of compressed air could be reduced by liquid honing alone. Not only can this be significantly reduced compared to the case where the semiconductor container C is finished, but also because synthetic resin packages are resistant to a large amount of compressed air. I discovered that it can be improved.

It is an object of the present invention to also provide an injection deburring method and apparatus which reduce the amount of compressed air consumed and are suitable for deburring molded products that have deburring in the contact area with metal. .

The method of this invention involves applying an electrolytic stripping method using the molded product as one pole before the process of continuously deburring the molded product where the contact area with the metal is exposed by liquid honing. This is an injection deburring method that reduces the amount of compressed air consumed.

An example of a device for carrying out the above method is shown in FIG. 4, as shown in FIG. 4, opposing inner links 2. z, there are clamping parts 3, 3' into which each end of the lead frame A can be inserted, and a lead frame A molded with synthetic resin, for example, as a package B, is inserted into the clamping parts 3, 3', and is continuously It is continuously fed by the rotating driving chain wheel 4 and driven chain wheels 5, 6, 7, 8.9, and first, an aqueous solution of caustic soda (30 to 45%) is heated to 70°C as an electrolyte. The lead frame A was passed through the electrolytic solution tank (2) as a cathode.

In the tank 1, 10 is a cathode shoe, 11 is an anode, and 12 is a power source.The voltage beam is C2 to 12V, the one used is 6V, and the current density is 2 to 12 A/100 ctr.
t, the adopted one was 5 A/100 crtt, and the electrolysis time was 60 seconds.

The lead frame A that has undergone electrolytic peeling under these conditions is then deburred by liquid honing using a liquid honing device (2).As a result, the liquid honing conditions are as follows: Injection pressure 1
．． 5, with two #4 nozzles, a distance of 100 mrn, and a feed rate of 10 m/min, deburring was completed completely and no whitening of the package occurred.

The amount of compressed air consumed at this time was 0.7 m37 m1n.

In addition, the part marked ■ in FIG. 3 shows the place where the lead frame to be processed is supplied to the clamping parts 3, 3' of a pair of chains, and the processed lead frame is lifted 9ffl from the pair of chains.

Various methods can be considered, but in this embodiment, as shown in FIG. 5, a pair of chains 1, 1' are provided on a pedestal 13, and a pair of guide grooves 14 whose spacing gradually widens and gradually narrows. 14', the gap becomes gradually thicker (the processed lead frame A1 is discharged from the clamping parts 3, 3' to the pedestal 13, and the new processed lead frame A2 is placed in the gap gradually narrower). It is designed to be inserted into the holding portions 3, 3' that move forward.

The conditions for the liquid honing process described above are the processing conditions for a single liquid honing process.

Grinding powder #180, injection pressure 2, compressed air consumption 3.4
4m3/min 1 nozzle #4 x 8 pieces, injection processing distance 1
00, the feed speed is 2.5 m/min, the injection air pressure is 1.5 x 72 x 20, 75.75%, the feed speed is 10 m/min /2.5 m/m1n = 4 times,
Injection air volume is 0.7 m”/min/3-44
m3/min 20.2.20 The compressed air consumption is about 10KWH even after subtracting the power consumption for electrolysis.
It can be reduced to 172 in about 20 minutes, and the lead frame processing efficiency is 4.
There are two types of electrolytic stripping methods: an anode method and a cathode method, but in cases such as lead frames, the cathode method generates a larger amount of H2 gas and is less likely to elute metal. However, if the frame is not made of iron, for example aluminum, the anodic method is better.

In addition, another embodiment of the apparatus for carrying out the deburring method of a lead frame in which a package is molded is shown in the sixth embodiment.
As shown in the figure, a driving chainwheel 16 that continuously rotates a pair of endless chains 15, 15', driven chainwheels 17, 18° 19, 20, 21, and driven chainwheels 18° 19 are placed close to the electrolyte level 22. The endless chain is installed so that it approaches the electrolyte surface 22, and one guide punch 23, 24 with a constant interval m is provided parallel to the bottom of the endless chain, so that a part of the endless chain is immersed in the electrolyte solution. established,
Connecting punches 26 are fixed perpendicularly to the endless chains at regular pitches between the opposing inner links of a pair of endless chains 15 and 15', and a liquid honing device ■ is installed next to the electrolyte tank ■, and the package is The molded lead frame A has short metal wires 3 on the vertical sides 28, 28 of a rectangular metal frame 27.
For example, the metal frame 27 is fixed in several stages by welding, and fishing portions 32, 32 are provided on the side 3L 31 of the metal frame 27 so as to be within a plane that includes the rectangular metal frame 27. Part 3
2 is hooked on the connecting punch 26, and the other is inserted within the interval m between the pair of guide punches 23, 24, and the connecting punch 26 passing above the electrolyte surface 22 is connected to the cathode terminal of the battery 25. 33, 34 in Figure 6 is the anode,
Reference numeral 35 indicates an injection nozzle.

Since this embodiment has a diagonally upward configuration, the upper fishing part 32 of the metal frame 27 is hooked to the connecting punch 26 of the endless chain 15, 15' in front of the electrolyte tank When the part 32 is inserted between a pair of guide punches 23° and 24 and fed,
The lead frame A, which is fixed to the metal frame 27, becomes a cathode in the electrolytic solution tank and performs an electrolytic stripping action, making it easy to puncture or peel off the flash or other particles. Grinding slurry is injected from the injection nozzle 35, and the above-mentioned flash or flash is completely removed.

According to the method and apparatus according to the present invention, the molded product that has pars in contact with metal, for example, the pars or flash of a lead frame in which a package is molded, can be removed by the electrolytic stripping method in the first step. Since the condition becomes easy, there is no need to use high pressure compressed air pressure for the next process of liquid honing, and the amount of air injected into the east of 75 in the case of single liquid honing is 175 units.The amount of compressed air for deburring the lead frame is reduced to 5 units. As a result, the equipment cost and power cost of the air compressor can be reduced, and this has a remarkable effect that can greatly contribute to cost reduction of the above-mentioned molded product, for example, the semiconductor melter C.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a semiconductor, Fig. 2 is a perspective view of a part of a lead frame in which a package is molded, and Fig. 3 is a device used in the injection deburring method for reducing compressed air consumption according to the present invention. A front view of an example, FIG. 4 is a perspective view showing a state in which a lead frame is held by a pair of endless chains, and FIG. FIG. 6 is a front view of another embodiment, FIG. 1 is a perspective view of the lead frame mounting frame, and FIG. 8 is in FIG. 6. A longitudinal side view taken along the line ■-■ is shown, respectively.

Claims (1)

[Claims] 1. Before the process of continuously deburring a molded product that has deburrs in the contact area with metal by liquid honing,
An injection deburring method for gradually reducing compressed air consumption, characterized by passing through a step of applying an electrolytic stripping method using the molded product as one pole. 2. An electrolytic solution tank (■) and a honing device (■) are installed side by side, and a pair of endless chains that continuously rotate in parallel to each other are provided, passing through the honing device (■) from above the electrolytic solution tank (■), Between the chains, the molded product A, which has a sharp edge in contact with the metal, is held, and the endless chain allows the molded product A to serve as one pole in the electrolytic solution tank I, and to absorb the electrolytic solution. An injection deburring device for gradually reducing consumption of compressed air, characterized in that the injection deburring device is provided so as to be immersed in and passed through, and then passed in front of an injection nozzle of a liquid honing device.