JPH05299572A - Lead frame cleaning and drying device - Google Patents

Abstract

PURPOSE:To provide a lead frame cleaning/drying device where organic solvent is not used. CONSTITUTION:A first and a second cleaning tank, 5 and 6, filled with cleaning liquid mainly composed of pure water and interfacial active agent, a third and a fourth cleaning tank filled with rinsing pure water, and a drying chamber are arranged in series. A transfer means 22 is provided to transfer works 3 following a set route. The tip of a jet nozzle 19 of the first cleaning tank 5 is set lower than solution level. The liquid temperature of the fourth cleaning tank is set higher than those of the other tanks. A drying blower is movable in the thicknesswise direction of a lead frame. A stopper is provided at the rear end of the drying chamber to tentatively stop the work 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame cleaning / drying apparatus which does not use an organic solvent or the like.

[0002]

2. Description of the Related Art A lead frame used for manufacturing a semiconductor device is formed into a desired shape by stamping a copper- or iron-based material. At this time, a stamping oil (containing a rust preventive agent) is used to protect the blade (blade) of the press machine, but if this oil remains attached, it will hinder the subsequent plating process and semiconductor chip assembly process. , It is necessary to clean the lead frame before the line is put in.

For such cleaning, organic solvents such as 1.1.1 trichloroethane and Freon solvent have been frequently used (for example, JP-A-61-230347).

[0004]

However, in recent years, the movement of dechlorofluorocarbons and dechlorination organic solvents has become active due to environmental problems, and this movement is unavoidable even among semiconductor manufacturing departments. Therefore, it has been desired to develop an apparatus and method capable of cleaning the lead frame without using an organic solvent.

[0005]

The present invention has been made in view of the above-mentioned drawbacks, and its main feature is to use a cleaning liquid containing a surfactant as a main component as a cleaning liquid for a lead frame. Also, arrange the tip of the cleaning liquid jet nozzle below the liquid surface of the cleaning tank, prepare multiple cleaning tanks, and make the liquid temperature of the last tank higher than others. The present invention provides a lead frame cleaning and drying apparatus that realizes a deorganized solvent, by moving a drying blower and providing a stopper member that temporarily stops a work conveyed near the drying blower.

[0006]

According to the present invention, the treatment can be performed with the cleaning liquid containing water as the main component. Besides, since the jet nozzle is inside the cleaning liquid, it is possible to suppress foaming due to the detergent.
You can give a thermal shock to the lead frame by setting the temperature higher than others. By moving the dry blower in the weight direction of the stacked lead frames, peeling the stacked lead frames one by one. By providing the stopper means which can be dried, it has an effect that the drying process can be performed for a time longer than the conveying speed of the conveying means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 and 2 are schematic views of a lead frame cleaning / drying apparatus according to the present invention.
Shows the left half of the device and FIG. 2 shows the right half of the device. The actual device is a device that combines FIG. 1 and FIG. 2 and is integrated from cleaning to drying.

With reference to FIGS. 1 and 2, this apparatus is roughly divided into two parts, a cleaning part ( 1 ) and a drying part ( 2 ). The cleaning section ( 1 ) is a loading section ( 4 ) for a work (3) containing a large number of lead frames, a first cleaning tank (5), a second cleaning tank (6), and a third cleaning tank (3). , And a fourth cleaning tank (8). The drying section ( 2 ) is the fourth cleaning tank (8).
From the drying stage ( 9 ) and a carry-out section ( 10 ) for carrying out the work (3).

From the carry-in section ( 4 ) to the carry-out section ( 10 )
Everything on the workbench is covered with a clean bench (11), and an exhaust duct (12) is provided for each stage to exhaust the atmosphere. Carry-in section ( 4 ) of clean bench (11)
The carrying-out section ( 10 ) and each stage are separated by a vertically movable shutter (13) to shield the atmosphere from the outside. Also, the first to fourth cleaning tanks (5)
~ D at the end of each (8) and in front of each shutter (13)
An AIR nozzle (14) for ejecting RY AIR is provided.

The first and second cleaning tanks (5) and (6) are made of a 10% aqueous solution prepared by mixing a nonionic surface active agent such as New Apollon (NE: Shinwa Kasei) into pure water. It is filled with the cleaning liquid (15). At the bottom of each washing tank (5) (6) is a tank (1) of washing liquid (15).
6), the cleaning liquid (15) is constantly supplied by the pump (17), and the overflowing cleaning liquid (1)
5) is discharged to the lower tank and circulated by a drain pipe. Cleaning solution in cleaning tank and tank (1
5) is heated to a water temperature of 40 to 50 ° by the heater (18). In the first washing tank (5), a nozzle (19) for ejecting the washing liquid (15) toward the work (3) submerged in the washing tank (5) is positioned such that its tip is submerged below the liquid surface. Are installed in the
The cleaning liquid (15) is constantly jetted at a pressure of 0 atm.
No jet nozzle (19) is provided in the second cleaning tank (6),
The cleaning liquid (15) is gently circulated. In some cases, the first and second cleaning tanks (5) and (6) may be integrated. In this case, the jet nozzle (19) may be arranged in the first half of the tank. Also, the first and second cleaning tanks (5) (6)
An ultrasonic cleaning device (US) is provided at the bottom of the.

The third and fourth cleaning tanks (7) and (8) use pure water as the cleaning liquid (20) to wash away the cleaning agent. Ultrapure water heated by steam is supplied to the fourth cleaning tank (8) and heated to a water temperature of about 70 ° by a heater (18). The used ultrapure water that overflowed the fourth cleaning tank (8) is supplied to the tank (16) installed at the lower part of the third cleaning tank (7). Primary pure water (RO) whose purity is slightly lower than that of the fourth cleaning tank (8) is constantly sprayed by the pump (P) into the third cleaning tank (7), and 40-50 by the heater (18). It is kept at a water temperature of °. The pure water is supplied to the third cleaning tank (7) by an ejection nozzle (19) whose tip is located below the liquid surface. This jet nozzle (19) is equivalent to that of the first cleaning tank (5). An ultrasonic cleaning device is installed at the bottoms of the third and fourth cleaning tanks (7) and (8).

The conveying means (22) of the drying section ( 9 ) is inclined at an angle of 5 to 10 so as to be a downward slope. Blowers (21) for blowing dry air for drying onto the work (3) are arranged at two locations above it. Blower (21)
Is a DRY heated to around 60 ℃ by a heater
AIR is jetted. Next, the detailed configuration of the main part will be described with reference to the drawings after FIG.

FIG. 3 is a perspective view showing the work (3).
The work (3) is a box made of stainless steel rods with a thickness of several mm, which is framed in a cube, and this frame is bridged with a large number of rods so that liquid and gas can pass freely. Is becoming This work (3) has 40 to 200 strip-shaped lead frames (23) stamped.
It is designed so that it can be stored vertically in the stacked state (the orientation shown in the drawing).

The work (3) accommodating the lead frame (23) is first loaded into the carry-in section ( 4 ) and delivered by the delivery means (2).
It is carried out to the carry-out section ( 10 ) by 2). Details of the transport means (22) are shown in FIGS. 4 is a plan view showing the conveying means (22), FIG. 5 is a side view, and FIG. 6 is a front view. The transport means fixes two L-shaped rails (24) in parallel, and mounts rotatable rollers (26) having a common shaft (25) on the fixed rails (24) at equal intervals. Further, it is a conveyor in which each roller (26) is connected by two chains (27) having a common shaft (25).
The shaft (25) of the roller (26) and the shaft (25) of the chain (27) are 5 to 7 mm thick stainless steel rods,
Work pieces (3) can be placed on them with a pitch of several cm. In addition, a locking member (2) that restricts the movement of the work (3) at regular intervals of about 600 mm.
8) is fixed to the shaft (25). Locking member (28)
Is a plate, a pin, or the like, as long as it can stop the movement of the work (3) in the transport direction. Rail (24)
Is the work (3) from the carry-in section ( 4 ) to the carry-out section ( 10 )
An unillustrated motor is connected to the chain (27). Then, the rotation of the motor causes the roller (26) to move while rotating on the rail (24), so that the work (3) placed on the shaft (25) is conveyed at a constant speed. There is. The chain (27) is connected endlessly in a loop.

7 (a), 7 (b) and 7 (c) are a front view, a side view and a bottom view showing the ejection nozzle (19), respectively.
This nozzle (19) has a first and a third cleaning tank (5) (7).
It was installed in. A through hole (29) having a diameter of 0.5 to 1.0 mm and a cutout are provided at the tip of the nozzle (19), and the cleaning liquid (15) is sprayed in a fan shape by the cutout (30).

FIG. 8 is a view of the cleaning tank provided with the nozzle (19) as seen from above. Two nozzles (19) are connected to one pipe (31), and the pipes (31) are attached at two front and rear positions. The two nozzles (19) have a pipe (3
In 1), the pipe is attached in a direction parallel to the carrying direction, and in the other pipe (31), the pipe is attached in a direction perpendicular to this.
One of the pipes (31) is attached by movable means (not shown) so as to be horizontally movable in the vertical direction in the drawing, and the other of the pipes (31) is rotatably attached by movable means (not shown). Instead of rotation, horizontal movement in the horizontal direction of the drawing may be used. The tip of the nozzle (19) is arranged at a position below the liquid surface of each cleaning tank (5) (7),
A work (3) accommodating the lead frame (23) in the direction shown in the figure is designed to pass under the nozzle (19) by the conveying means (22).

9 (a), (b) and (c) are respectively a front view, a side view and a bottom view showing the blower (21) of the drying section ( 2 ). The blower (21) is a plastic molded product, and blow-out holes (32) having a diameter of several mm are arranged vertically in a line at the tip thereof. FIG. 10 is a view of a part of the drying unit ( 2 ) viewed from above. Three blowers (21) in FIG. 9 are arranged in series in parallel with the direction of the lead frame (23) to
It is a unit. Three of the units are attached by movable means (not shown) so as to be horizontally movable (vertical direction in the drawing) in the thickness direction of the lead frame (23) at the same time. The work (3) placed on the transfer means (22) passes under the blower (21). A stopper means (33) for temporarily stopping the work (3) is provided immediately below the blower (21). Stopper means (3
3) is composed of a spring or the like, has a strength enough to cause the work (3) to slide against the movement of the transfer means (22), and has the locking means (28) of the transfer means (22). ) Has a strength to open the work (3) when pressed.

The blower (21) of 3 units 1 unit is shown in FIG.
As shown in FIG. 1, three places are arranged on the conveying means (22). The interval between the locking means (28) of the transfer means (22) (referred to as one station) is 600 mm, and at this time, the blower (21) of the three units is the stopper means (33).
To 1000 mm are evenly spaced. The transfer means (22) transfers one work (3) per station.

The process of the work (3) from loading to unloading will be described below step by step. Referring again to FIGS.
Workpiece containing 40 to 200 lead frames (3)
Is manually placed on the transport means of the loading section ( 4 ). The work (3) placed on the carrying means is carried into the apparatus according to the transfer speed (600 mm / 80 sec) of the carrying means (22). First, the shutter (13) is opened in association with the movement of the transport means (22), and the work (3)
To the clean bench (11). Transport means (2
Immediately after that, 2) is inclined upward, and by this inclination, the work (3) is slid down on the transfer means (22) until it is locked by the locking means (28) of the transfer means (22), and the work (3) is slid. The positions of the works (3) are aligned so that each processing time for () is constant.

The work (3) transferred by the transfer means (22) is first introduced into the first cleaning tank (5) filled with the cleaning liquid (15). At this time, the transport means (2
2) is inclined downward toward the first cleaning tank (5), and the work (3) slides down on the transfer means (22) by one station (600 mm) by gravity and the other locking means. It is locked by (28). The conveying means (22) inclined downward is in a horizontal state near the bottom of the first cleaning tank (5) and is inclined upward again when leaving the first cleaning tank (5). Workpiece (3) is cleaning liquid (15) when horizontal
It is completely submerged and passes below the jet nozzle (19). When passing below the jet nozzle (19), the lead frame (23) housed in the work (3) is primarily cleaned by the cleaning liquid (15) jetted from the jet nozzle (19) at a pressure of 35 to 70 atm. To be done. The spouting state of the cleaning liquid (15) is as shown in FIGS. If necessary, use ultrasonic cleaning together. In the present invention, a jet nozzle (19)
As a result of arranging the tip of the cleaning liquid (15) below the liquid surface of the cleaning liquid (15), the cleaning liquid (15) does not entrap air, and therefore foaming of the cleaning liquid (15) can be suppressed. Nozzle (1
When 9) is provided above the liquid surface, the foaming is severe and the foam reaches the adjacent cleaning tank and causes trouble. In addition, the cleaning liquid (1
A nonionic surfactant is used for 5). When an ionic system is used, copper and ions react with each other when the copper agent and the frame are washed to form a hydroxide on the surface of the lead frame (23).

The work (3) from which most of the oil and dirt have been removed in the first cleaning tank (5) is drained by the AIR nozzle (14), and after passing through the shutter (13) the second cleaning tank ( It is transported to 6). The second cleaning tank (6) is filled with the same cleaning solution (15) as that of the first cleaning tank (5), and the work (3) immersed in this cleaning solution (15) is ultrasonically cleaned to obtain the lead. Secondary cleaning of the frame (23) is performed. The first and second cleaning tanks (5) and (6) may be integrated into a single jet nozzle (19) -ultrasonic cleaning flow. Further, since the form of the transport means (22) of downward-horizontal-upper is common to each cleaning tank, the description thereof will be omitted.

The work (3) that has undergone the primary and secondary cleaning is
It is guided to the third cleaning tank (7) by the transfer means (22). In the third cleaning tank (7), pure water containing no detergent is used as the cleaning liquid (20), and the surfactant remaining in the lead frame (23) is jetted from the jet nozzle (19) at a pressure of 35 to 40 atm. Wash off with cleaning solution (20) and ultrasonic cleaning. The form of the jet nozzle (19) is the same as that provided in the first cleaning tank (5). Further, the third cleaning tank (7) may be configured not to be filled with the cleaning liquid (20) but only to spray the cleaning liquid (20). That is,
It is a state in which the cleaning liquid (20) is constantly sprayed from top to bottom and discharged.

The work (3) which has been rinsed by the third cleaning tank (7) is transferred to the fourth cleaning tank (8) by the transfer means (22). Since the fourth cleaning tank (8) is the final cleaning, primary pure water having the highest purity is used as the cleaning liquid (20). Further, while the liquid temperature of the first to third cleaning tanks (5), (6) and (7) is 40 to 50 ° C, the fourth cleaning tank (8) is heated to about 70 ° C by steam. , Set to high temperature. By setting the temperature to a high temperature, the lead frame (23) soaked in the cleaning liquid (20) is thermally shocked by thermal expansion, and the dirt attached to the lead frame (23) is easily removed by ultrasonic cleaning.

First to fourth cleaning tanks (5) (6) (7)
The work (3) washed by (8) is transferred to the drying section ( 2 ) by the transfer means (22). In the transport means (22) of the drying section ( 2 ), the work (3) is attached to the shaft (2
5) The rail (24) is inclined downward at such an angle that it can slide down. From the blower (21) installed above the transfer means (22), the DRY AIR heated to around 60 ° C. by the heater is blown out toward the lead frame (23) to dry the water adhering to the lead frame (23). Let The blower (21) reciprocates in the thickness direction of the overlapping lead frames (23) as shown in FIG. Drying is relatively easy when an organic solvent such as CFC is used, but when water is used as in the present application, the lead frame (23) is caused by the surface tension of water.
May adhere tightly. When the blower (21) is aligned with the direction of the lead frame (23) and moved in the weight direction, a force acts to open the lead frames (23) that are superposed one by one. Even in (23), it is possible to dry one by one.

A stopper means (33) for stopping the work (3) immediately below the blower (21) is provided near the end of the drying section ( 2 ) as shown in FIG. The stopper means (33) operates as shown in FIG. First, the work (3) slides down on the conveying means (22) by the inclination and is held by the locking means (28) (a). When the work (3) comes into contact with the stopper means (33) due to the movement of the transfer means (22), the stopper means (33) stops the work (3) at that position against the movement of the transfer means (22) (b). ). When the next locking means (28) pushes the stopped work (3), the stopper means (33) is released by the force, and the stopped work (3) slides down (c). The stopper means (33) stops the next work (3) and returns to (a) (d). In this way, the stopper means (33) temporarily stops the work (3) immediately below the blower (21), so that the lead frame (23) of the work (3) can be moved for a time period corresponding to the transfer speed of the transfer means (22). It can be dried for a longer time.

After that, the shutter (13) which shields the atmosphere of the drying section ( 2 ) from the outside air is opened and closed, and the work (3) is carried out to the carry-out section ( 10 ) by the carrying means (22) and the lead frame ( The washing and drying in 23) is completed. With the apparatus of the present invention described above, the lead frame (23) can be washed with pure water and a surfactant. Moreover, by making the tip of the injection nozzle (19) below the liquid surface, it is possible to suppress the foaming of the cleaning liquid (15). By applying a thermal shock with a temperature difference, even the dirt firmly adhered can be removed. By reciprocating the blower (21), which can be dropped, in the thickness direction of the lead frame (23), the lead frames (23) adhered by the surface tension of water can be dried as if peeled off one by one. Since there is no residue, the work (3) can be temporarily stopped by the stopper means (33),
It is characterized in that it can be dried for a longer time than the time determined by the transport speed.

[0027]

As described above, according to the present invention,
This has an advantage that the lead frame (23) can be washed with pure water and a surfactant. Since it does not use organic solvents such as CFCs, it can be applied to environmental problems. further,
By arranging the tip of the nozzle (19) below the liquid surface, it is possible to suppress the foaming of the detergent, the effect that the dirt firmly adhered by the thermal shock and the detergent residue can be removed, and the lead frame (23) It also has the effect that the water content can be completely dried by drying so as to peel off one by one, and that the stopper means (33) can increase the drying time and increase the transport speed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a device of the present invention.

FIG. 2 is a diagram showing an outline of the device of the present invention.

FIG. 3 is a perspective view showing a work (3) and a lead frame (23).

FIG. 4 is a plan view showing a conveying means (22).

FIG. 5 is a side view showing a conveying means (22).

FIG. 6 is a front view showing a conveying means (22).

FIG. 7 is a view showing an ejection nozzle (19).

FIG. 8 is a view showing a jet nozzle (19) and a work (3).

FIG. 9 shows a dry blower (21).

FIG. 10 is a diagram showing a drying unit ( 2 ).

FIG. 11 is a diagram showing a drying section ( 2 ).

FIG. 12 is a view for explaining the operation of the stopper means (33).

Claims (5)

[Claims] 1. A cleaning liquid containing a surfactant and water as main components, a cleaning tank for containing the cleaning liquid, and a nozzle for ejecting the cleaning liquid, the tip of the nozzle being the liquid surface of the cleaning liquid in the cleaning tank. A cleaning device for a lead frame, which is arranged below the cleaning device. 2. The lead frame cleaning apparatus according to claim 1, wherein the cleaning liquid is a nonionic system. 3. A lead frame cleaning apparatus, wherein a plurality of cleaning tanks containing a cleaning liquid containing water as a main component are connected in series, and the lead frame is soaked in order to perform cleaning. An apparatus for cleaning a lead frame, comprising: 4. A work in which a large number of strip-shaped lead frames are stacked and housed is immersed in a cleaning liquid containing water as a main component to be cleaned,
A lead frame drying device for subsequently blowing air to dry the lead frame drying device, wherein the air blowing blower is movable in the thickness direction of the lead frame. 5. A slope is provided so that the slope is downhill,
A conveyor-type transfer means for placing and transferring the work containing the lead frame thereon, and the transfer means capable of sliding the work according to gravity, and the transfer means Locking members for stopping are provided at regular intervals, are arranged near the end of the inclined conveying means, and are installed at positions corresponding to the blower and the blower for blowing air to the lead frame of the work, and temporarily hold the work. And a stopper means for releasing the held work by the subsequent pressing of the locking member.