JPS6156620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for continuously plating leads on electronic components.

Generally, when attaching electronic components such as diodes to wiring boards, etc., a method is adopted in which leads of the electronic components and terminals of the wiring board are fixed with solder in order to achieve good electrical connection between the leads and the terminals of the wiring board. For this reason,
The diode leads are soldered.

Conventionally, a molten solder dipping method is known as one of these solder plating methods. This is a method in which pretreated diode leads are temporarily immersed in molten solder to cover them with solder. The plating devices include (1) a molten type plating device that simply inserts molten solder, (2) a plating device with an ultrasonic oscillation mechanism that vibrates the molten solder, and (3) a plating device that applies molten solder. Flow solder type plating devices and the like are known in which the liquid is jetted partially higher than the liquid level.

However, in the device (1), in order for the solder to adhere well to the leads, flux, which serves as an activator (plating promoter), must be administered into the liquid. Since this flux needs to be removed from the object to be treated after plating, cleaning treatment is required after plating, which has the drawback of increasing the number of work steps.

In the device (2), the contact surface between the lead and the molten solder is activated by ultrasonic oscillation, so there is no need to use flux and there is no need for cleaning after plating. However, since the liquid surface portion of the molten solder comes into contact with air, it is easily oxidized and oxides are easily generated, and this oxide covers the entire liquid surface. Therefore, when antioxidants (peanut oil, balm oil, etc.) are not used, oxides floating on the liquid surface often have to be mechanically removed. Therefore, there is a drawback that the object to be plated cannot be continuously placed in the plating tank.

In the device (3), unoxidized molten solder sequentially flows out from the jet port, and even if the molten solder that flows out comes into contact with air and is partially oxidized, these oxides flow out of the guide 16. Therefore, oxides are less likely to adhere to coated objects. For this reason, there is no need to remove oxides, so it is possible to continuously immerse the object to be plated, but in order to improve the adhesion of solder to the object with this device, it is necessary to melt the flux. It must be mixed into the solder.

In addition, when applying solder plating to diode leads using these plating devices, conventionally,
Since the leads protruding in both directions from the diode's glass envelope were plated separately, the workability of the plating process was low.

Therefore, an object of the present invention is to provide a plating method that does not require cleaning treatment after plating and can continuously and efficiently apply good plating to a plated object having a plurality of plated parts. The goal is to provide equipment.

In order to achieve such an object, the present invention moves a conveying mechanism that automatically supplies and carries out plating objects on two plating tanks arranged in series, and each of the conveying mechanisms A device that uses one plating tank to plate a part of the plated object that is magnetically held in the holding part, and then plate the other part of the plated object in the other plating tank. In addition, each plating tank has a flow solder structure in which ultrasonic vibration is applied to the solder part that rises from the molten solder liquid level, and the transfer mechanism has a It has an inversion mechanism that changes the holding state of the covered object in the holding part up and down,
The present invention will be explained below with reference to Examples.

1 to 4 show an embodiment of the continuous lead plating device for electronic components of the present invention, FIG. 1 is an external view showing the outline thereof, and FIG. 2 is a partial sectional view showing the plating state. FIG. 3 is an exploded perspective view showing a part of the diode transport mechanism, and FIG. 4 is a partially sectional plan view showing the diode reversing mechanism. FIG. 1 shows a first plating tank 1 and a second plating tank arranged in series.
A plating tank 2 is shown. All of these plating tanks have the same structure, and a plating tank 3 having a heater at the bottom is divided into an upper chamber 5 and a lower chamber 6 by a horizontally extending separator 4, and this separator Holes are made in two places in 4, and an impeller rotated by a rotating mechanism 7 is fitted into one of the holes, and the plating liquid (for example, molten solder) 8 in the upper chamber 5 is transferred into the lower chamber 6 by the rotation of the impeller. The structure is such that the molten solder flows into the separator plate 4, and the molten solder under high pressure is blown up from the other hole (jet port 9) above the separator plate 4. Furthermore, since the peripheral edge of the jet port 9 protrudes higher than the molten solder liquid level and serves as a guide 10 for the flow of the jet solder, the jet solder is jetted higher than the molten solder liquid level. Further, the oscillators 12 of two ultrasonic oscillation mechanisms 11 penetrate and enter a part of the guide 10 from diagonally above, and the vibrations of the oscillators 12 cause the solder jet inside the guide 10 to vibrate ultrasonically. It's becoming like that.

On the other hand, above both plating tanks 3, as shown in FIG. 1, first and second conveyance mechanisms 13 and 14, which are composed of chain mechanisms and move in endless tracks, are respectively disposed. These transport mechanisms 13 and 14 have a holding mechanism 15 having a structure as shown in FIGS. 2 and 3. That is, this holding mechanism 15 consists of a U-shaped holding block 16 made of a non-magnetic material, and a permanent magnet 17 attached to a recess of this holding block 16.
8 to an attachment 20 attached to the chain 19. Also, holding block 1
Three housing grooves 21 extending in the vertical direction are provided on the side surface of the chain 6 (a surface parallel to the side surface of the chain). These housing grooves 21 are long grooves with a V-shaped groove bottom, and are adapted to accommodate a plated object such as a glass portion 23 of a diode 22 and a lead 24 made of metal. In addition, a housing surface 25 in which the housing groove 21 is provided.
One side edge serves as a thin shielding piece 26 that extends on the extension of the accommodation surface 25. Further, the other side edge of the shielding piece 26 forms a partially recessed recess 27 by the same dimension b as the thickness a, so that the adjacent holding block 16
The shielding piece 26 of the screen is made to face. This is provided to prevent gaps from forming between adjacent holding blocks 26 even when the chain 19 is bent.
When attracting the diode 22 to 1 by magnetic force,
This is the result of consideration being taken so that the diode 22 is not sandwiched between adjacent holding blocks.

The first conveyance mechanism 13 moves along guides (guide rollers) indicated by 28 to 35. Between the guides 28 and 29 is a horizontally moving part, which crosses the loader part 36 and accommodates the diode 22 held by the loader part 36 in each accommodation groove 21 of the holding mechanism 15. The loader section 36 has a U-shaped cross section, and lines of magnetic force run vertically in parallel. Therein, therefore, the leads 24 of the diode 22 are magnetized and extend vertically away from each other. There is a downward slope between the guides 29 and 30, and a position correction plate 37 having a slope steeper than that of the chain is disposed above the guide, and the upper end of the diode 22 held by the holding mechanism 15 is lowered. The position of the diode 22 with respect to the holding block 16 is always constant at the time when the diode 22 is pushed downward and removed from the position correction plate 37. That is, as shown in FIG. 2, only the upper lead 24 of the diode 22 enters the accommodation groove 21, and the lower lead 24
It protrudes below the lower end of the holding block 16 to facilitate fitting. The guides 30 and 31 are again moved horizontally, and during this time the lower leads 24 are immersed in the jet soldering liquid, as shown in FIG. Between the guides 31 and 32, it rises at an upward slope, and between the guides 32 and 33, it moves horizontally again. Further, between the guides 33 and 34, the chain is inverted and moves horizontally. Therefore, the plated leads 24 are located at the top, and the unplated leads 24 are located at the bottom. Further, as shown in FIG. 4, a removal rod 38 is disposed diagonally across this moving area. This removal rod 38 is arranged so that as the chain moves forward, the diode 22 in the receiving groove 21 moves from the bottom toward the entrance. The diode 22 removed from the holding mechanism 15 enters the transfer stocker 39 that forms parallel magnetic flux in the vertical direction, and is held in the magnetic field. Also, this transfer stocker 39
The magnetic force at each part is non-uniform, and as shown in FIG. 4, the magnetic force gradually becomes stronger as the diode 22 sequentially moves in the direction of the arrow. Also, 34,
Between the guides 35 and 28 there is an upward slope and the height is the same as the upper edge of the guide 28, and between the guides 35 and 28 there is again a horizontal movement section. and,
This horizontally moving section passes through a tubular heater 40, and the chain is preheated to preheat the diode 22 held therein.

On the other hand, the second transport mechanism 14 moves along guides (guide rollers) indicated by 41 to 46. This second transport mechanism 14 is almost the same as the first transport mechanism 13. That is, the horizontal movement range between the guides 41 and 42 passes through an area where the magnetic force of the transfer stocker 39 is strong, and the diode 22 whose upper lead is soldered is attracted and held by the holding block 16 by the magnetic force. Further, between the blocks 42 and 43, the lower lead 24 is corrected by the position correction plate 47 so as to protrude below the lower end surface of the holding block 16, and the lower lead 24 is moved between the guides 43 and 44. Put it in solder liquid and plate it, 44,
The diode 22 rises between the guides 45 and 48, and is caught by the removal rod 48 disposed to intersect with the chain in the horizontal movement area between 45 and 46, and the diode 22 is detached from the housing groove 21 and falls off. Enter 49,
The shutter 49 allows it to be carried to a desired position. Moreover, the area between the guides 46 and 41 becomes a horizontal movement area again, and this movement area passes through the tubular heater 50 and is preheated.

According to this embodiment, one lead of the diode to be plated is soldered while being continuously transported by the first transport mechanism, and the diode is reversed and placed in the transfer stocker 39. While the diode which has been plated on one side is continuously transported by the second transport mechanism, the remaining lead on the other side is solder-plated. Therefore, workability is good. Further, the plating bath has a jet structure, and the jet plating liquid is in an ultrasonic vibration state. Therefore, desired plating can be performed without mixing flux, antioxidant, etc. into the plating solution. Furthermore, since these additives are not used, the cleaning operation after staining that was conventionally required is also unnecessary.

Note that the present invention is not limited to the above embodiments. That is, although two sets (two chains) of chains were used in the embodiment, one chain may be disposed on two plating tanks. In this case, just twist the chain 180 degrees midway to change the top and bottom of the diode.

Further, as shown in FIG. 5, the upper part of the plating tank 3 is covered with a cover 51, and a supply pipe 52
Nitrogen gas may also be supplied from. Further, the cover 51 is provided with an insertion opening 53 into which a covered object is inserted. As a result, the plating solution does not come into contact with oxygen, so it does not oxidize and has the advantage of providing high-quality plating.

Furthermore, according to the plating apparatus of the present invention, as long as the object to be plated is an electronic component that can be attracted by magnetic force,
Not limited to diodes.

As described above, the continuous lead plating device for electronic components of the present invention does not require cleaning treatment after plating, and is suitable for continuous and efficient plating of objects having a plurality of plated parts. Can be tanned.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the continuous lead plating device for diodes of the present invention, FIG. 2 is a sectional view showing the same plating state, and FIG. 3 is a conveyance mechanism for holding and conveying the diodes. FIG. 4 is a partially exploded perspective view, FIG. 4 is a sectional view of the diode reversing mechanism, and FIG. 5 is a partially sectional view according to another embodiment of the present invention. 1...First plating tank, 2...Second plating tank, 3
...Plating tank, 4...Separation plate, 5...Upper chamber, 6...
... lower chamber, 7 ... rotation mechanism, 8 ... plating liquid (molten solder), 9 ... jet port, 10 ... guide, 11 ...
... Ultrasonic oscillation mechanism, 12 ... Oscillator, 13 ... First transport mechanism, 14 ... Second transport mechanism, 15 ... Holding mechanism, 16 ... Holding block, 17 ... Permanent magnet, 18 ... Screw , 19... Chain, 20... Attachment, 21... Housing groove, 22... Diode, 23... Glass portion, 24... Lead, 2
5... Accommodation surface, 26... Obstruction piece, 27... Recess,
28-35...Guide, 36...Loader section, 37
... Position correction plate, 38 ... Removal rod, 39 ... Transfer stocker, 40 ... Heater, 41 to 46 ... Guide, 47 ... Position correction plate, 48 ... Removal rod, 4
9... Shooter, 50... Heater, 51... Cover, 52... Supply pipe, 53... Insertion port.

Claims (1)

[Claims] 1. A transport mechanism that continuously has a holding part that magnetically attracts and holds electronic components and moves in an endless trajectory, two plating tanks arranged in series below the transport mechanism, and a transport mechanism that moves in an endless trajectory. The plating tank has a flow solder structure, and has a supply mechanism disposed at one end to supply electronic components to the holding section, and a carry-out mechanism disposed at the other end of the conveyance mechanism to remove the electronic components from the holding section. and has an ultrasonic vibration oscillation mechanism that vibrates the plating liquid that swells up, the conveyance mechanism has an inversion mechanism that converts the electronic component in the holding part up and down between the two plating tanks, and further A continuous plating device for leads in electronic components, which is provided with a position correction mechanism for correcting the holding position of the electronic component in the holding section on the supply side of each plating tank.