JPH02265219A - Apparatus for treatment of electrodes of chip component - Google Patents

Abstract

PURPOSE:To treat an electrode of a chip component with good mass productivity by a method wherein a film or a layer composed of a low-melting metal (low-melting alloy) is melted on the side of a high-temperature part and is cooled on the side of a low-temperature part of a high-boiling liquid in a container. CONSTITUTION:When a high-boiling liquid in an inner-tube upper part 33 is heated by using a heater 30, a specific gravity of the high-boiling liquid 18 in the inner-tube upper part 33 inside a heated tube 28 is made small and is not circulated by convection together with the high-boiling liquid 18 of a low temperature whose specific gravity is large in the lower part and is circulated by convection only in the upper part. As a result, a part in the inner- tube upper part 33 on the inside of the tube 28 is set to a high temperature and a part in an inner-tube lower part 34 is set to room temperature; and a temperature gradient is formed and held. Chip components 7 are thrown, by using a supply machine 36, into the inner-tube upper part 33 which has been set to the high temperature. Accordingly, plated films as outermost layers of electrodes are melted at the heated inner-tube upper part 33; the components fall to a lower-temperature part where the temperature gradient has been formed; they are solidified; and treated chip components 26 provided with the electrodes whose surface is smooth fall to the bottom of the tube 28 and are collected in a basket 39. Thereby, a high- speed and large-quantity treatment can be executed continuously; and the chip components can be manufactured at a low cost.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an electrode processing device for chip components such as chip resistors, which are a type of electronic component that contributes to the reduction in weight, thickness, and size of electronic devices. be.

2. Description of the Related Art Conventionally, this type of chip component has had a structure as shown in FIG. Figure 2 shows a cross-sectional view of a square plate-shaped chip resistor as an example, where 1 is an insulating substrate made of alumina, 2 is a resistor, 3 is a silver thread electrode film, 4 is a nickel (Ni) film, and 5 is an electrical Solder deposited by the Metsuki method (Sn-Pb alloy)
[or tin (Sn) or lead (Pb)] film, 6 is a glass covering 1' for protecting the resistor 2! It is a membrane.

In this way, conventional chip components have a low melting point metal plating film or a low melting point alloy plating film (hereinafter collectively referred to as low melting point metal plating film) on the outermost layer of the electrode part, and also have a base layer ( Here, the nickel film 5) is a high melting point metal film or a high melting point alloy made of a material that has a higher melting point than the above-mentioned low melting point metal plating film and has good affinity with the low melting point metal plating film! (Hereinafter, these are collectively referred to as high melting point metal films).

In a chip component having such a conventional structure, the outermost layer of the electrode portion is made of a low-melting metal plating film, and the surface thereof is rough and has a very large surface area. For this reason, these films tend to absorb foreign matter and adsorb gases, and when stored for a long period of time, the electrode surface undergoes chemical changes such as oxidation, which sometimes results in poor soldering when soldering to printed circuit boards. There was a problem in that there was a high possibility that this would occur. In addition, when the low melting point metal plating film is made of glossy plating to make the surface smooth, it has the fatal drawback of poor soldering properties because it contains impurities (organic substances). ing.

Now, as an electrode processing device for smoothing the low melting point metal plating film, which has a rough surface on the electrode part as described above, an atmospheric furnace, an infrared furnace, a hot air furnace, a hot plate, etc. are used. A heating amount post-processing device or a device using a Heperface soldering method (VPS method) is known. Among these, as an example, electrode processing and equipment for chip components using an infrared heater will be described below.

FIG. 3 shows a schematic diagram of an electrode processing apparatus using this infrared heater.

In FIG. 3, 7 is a chip component having the structure shown in FIG. 2, 8 is a chip component alignment machine, 9 is a flux coating machine, 10 is an infrared heater, 11 is a cooler, and 12 is an electrode-treated device. Chip component removal machine, 13 is a belt drive unit, 1
4 is an electrode processing device mount; 15 is a chip component conveyor belt;
16 is a belt washer.

The process of melting the low melting point metal plating film on the electrode part of the chip components consists of five steps: ■ Aligning the chip components - ■ Flux application - ■ 1110 heat melting - ■ Cooling and solidifying → ■ Taking out the chip components .

That is, the chip components 7 are supplied from the deep component alignment machine 8 to the chip component conveying heald 15-1x conveyed by the belt drive unit 13, and after applying flux to the chip components 7 in the next step, tunnel-type infrared heating is performed. The electrode portion coated with flux is heated and melted using a device 10, and then the molten portion is cooled and solidified by a cooler 11. Thereafter, the chip component 7 that has undergone electrode treatment is taken out by an electrode-treated chip component removal machine 12. I'm going to take it out. Further, after the chip component conveying heald 15 is cleaned by a belt washer 16, the chip components 7 are again supplied thereon.

In such conventional electrode processing equipment, independent equipment is required for each process, and a cleaning device must be installed because the chip component conveyor bell becomes dirty with flux. The equipment had to become larger,
Moreover, in order to maintain the timing between each piece of equipment (to synchronize the transfer speed of the chip components transported by the conveyor belt and the timing of flux application and chip component removal)
The equipment had seven basic opening points, which required precision.

Problems with the above-mentioned electrode processing apparatus will be listed below.

■ When the electrode parts of the chip parts are melted, the individual chip parts must be spaced and aligned so that the electrode parts of the chip parts do not stick together, and this is a major factor that hinders mass production. Become.

(Since the metal is heated and melted in air, flux is required to prevent oxidation of the molten metal surface.)

■ Because flux is used, the flux gets heated and burns into the chip parts, making it difficult to clean the chip parts.

■ Since the heating section is a tunnel type, air can freely enter and exit, making it difficult to stabilize the temperature.

■ Since the conveyor belt is also heated at the same time, it takes time to heat and cool it, requiring a very long furnace and a cooler for rapid cooling.

■ The conveyor belt must be cleaned, as flux may adhere to the conveyor belt and cause equipment failure.

■ Considering the equipment as a whole, there are many mechanically moving parts, and flux is used on these parts, so flux adheres to the moving parts of the equipment, causing breakdowns and reducing the operating rate of the equipment.

As described above, the electrode processing apparatus using the infrared heater shown in FIG. 3 has many problems, and there is a strong demand for improvement thereof.

In addition, in the other electrode processing apparatuses mentioned above,
To a greater or lesser extent, this method has similar problems to the electrode processing device using an infrared heater.

The dimensions of the chip components are generally 3.2 mm.
It is as small as 1.6mm, and even more recently 2.0mm.
Very small chip parts such as 25 mm and 25 mm are coming into use, and there is a growing trend toward smaller size. In this way, the dimensions of the chip components are extremely small, and as mentioned above, the conventionally known T: and M processing equipment has a large number of problems. The reality is that in current chip components, there is almost no treatment to make the surface of the electrode part smooth.

Now, the present invention has proposed an electrode processing apparatus for chip components with a new configuration, which eliminates the drawbacks of such electrode processing apparatuses. The basis of these proposals, and the easiest to realize, is an electrode processing device for chip components having the configuration shown in Japanese Patent Application No. 174219/1982, whose schematic configuration diagram is shown in Figure 4. This is described below.

This device has an input section 20 which is filled with a high boiling point liquid 18 such as oil, and into which a chip component 7 having a film or layer made of a low melting point metal or a low melting point alloy is placed at one end of the electrode section. a cylindrical container 17 equipped with a heater 17, a heater 19 disposed at one end of the cylindrical container so as to create a temperature gradient in the high boiling point liquid, and a heater 19 disposed at the other end of the cylindrical container. A cock part 21.22 is installed below the cylindrical container 17, and a take-out part 23 for taking out the processed chip parts 26 is installed in the cock part fuq. It's a good thing.

Next, a method for treating the surface of the electrode portion of the chip component 7 using the apparatus shown in FIG. 4 will be described. First, in the stage of performing electrode processing, the upper cock 21 is opened and the lower cock 22 (Ill) is closed, as shown in FIG.

In this state, the glass cylindrical container 1 is heated using the heater 19.
Heat the upper part of Step 7 to 250-280°C. At this time,
Since the cylindrical container 17 contains coconut oil as a high boiling point liquid 18, this high boiling point liquid 18 is heated to 250 to 280°C. The heated high boiling point liquid 18 has a low specific gravity, and convection occurs only in the upper part on the side of the input part without convection in the low temperature part \'\ where the specific gravity is high in the lower part.

Therefore, a temperature gradient is created in the high boiling point liquid 18 in the cylindrical container 17 from a high temperature state to a low temperature state from the upper part to the lower part, and the bottom side can be kept at room temperature. Then, add the high boiling point liquid 18 to the prepared place as described above.
Chip components 7 having a low melting point metal plating film on the outermost layer of the electrode section are introduced into the cylindrical container 17 from the parts feeder 20 through an input section above the liquid level. Due to this injection, the chip component 7 falls into the high boiling point liquid 18. At this time, 25
The low-melting point metal plating film provided on the outermost layer of the electric conductor (4) is melted in the high-temperature section heated to 0 to 280°C, and falls to the low-temperature section side with a temperature gradient. The molten part is solidified on the side and collected as a processed chip component 26 with a smooth electrode in the cock 22 E on the bottom side of the cylindrical container 17. At this time, the bottom side of the cylindrical container 17 is at room temperature. Therefore, there is no need to worry about the treated chip components 26 sticking together.And, to take out the chip components 26 whose electrode surfaces have been treated, open the cock 21 and close the cock 22 during the electrode treatment, as described in 1. Now, when the treatment is completed, close the cock 21, and open the cock 22 with the bottom opening 24 of the cylindrical container 17 held at the liquid level by the high boiling point liquid storage container 23. The chip parts 26 that have undergone seed processing fall under their own weight onto the container 25. Next, after confirming that they have finished falling, the reticulated bones collect the container 25 and collect the high boiling point liquid 18 in the container 23. Removal is completed by pulling up from inside.

Thereafter, the processed chip component 26 taken out is washed to become a finished product.

According to the electrode processing device previously proposed by the present inventors,
A film or layer made of a low melting point metal (low melting point alloy) is melted on the high temperature side of the high boiling point liquid in the container and cooled on the low temperature side, so surface tension acts during melting and the surface area becomes small. , by being cooled in this state,
The surface area is extremely small compared to low melting point metal films (low melting point alloy films) formed with plating films, etc., and the surface is smooth, so there is extremely little adhesion of foreign matter or gas adsorption during storage. This means that chip parts can be obtained. In addition, when melting, foreign matter and debris that have been adsorbed or occluded on the surface or inside the depressions are released, so the outermost layer of pus itself becomes a clean l1%i containing no impurities, improving solder wettability. , and/or the chip parts connected to the credit/deposit direction will be f7. In addition, during the electricity treatment, the six products (high boiling point) (in the liquid body) are moved to the high one part side and to the lower one crystal part i υ:j, which requires complicated equipment. [It can be carried out as a part-time job without having to use heather. In addition, since melting and cooling are performed in the high boiling point 1α body, the electrodes of the chip components do not stick together on the low temperature side, so the chip components do not have to be aligned during electrode processing and are separated. Processing can be done by simply adding a large amount to the liquid, and since the chip parts are in contact with the liquid, heating and cooling can be completed in a short time, making it extremely suitable for mass production. Furthermore, since melting and cooling are performed in a high boiling point liquid and there is no chance of contact with air, there is no need to worry about oxidation of the electrode surface even during melting.
・It is t). Additionally, because melting is performed in a liquid, the specific gravity of the high-boiling liquid that is in contact with the molten material (low-melting metal, low-melting alloy, etc.) is higher than that of air, and the viscosity is also high. Therefore, pressure is applied to the molten metal from the surroundings, and the surface condition of the molten metal becomes a smooth surface without fading, resulting in a uniform thickness t3. Furthermore, by using oil such as natural vegetable oil or liquid with fluxing action such as Glyrelin as a high boiling point liquid, flux is not required, which simplifies the equipment and also makes it easier to clean processed chip parts. It becomes very easy.

As described above, the electrode processing device proposed by the present inventors largely solves the drawbacks of conventional devices, but it has the following problems in terms of automation, productivity, and safety. It is something that has.

■ To construct this cock-type device, it is easy to make it from glass, but if it is made of glass, there is a risk that the high-temperature, high-boiling liquid may leak out from the container if the container is damaged. , which poses a major problem in terms of safety.

■ In order to process a large amount of electrodes without causing the electrodes of the chip components to stick together during processing, it is effective to increase the opening diameter of the chip component input port.
For this reason, if the container is made of glass, there is a limit to the diameter of the input port, which limits the expansion of the equipment for high-volume, high-speed processing.

■ In order to solve the problems of ■ and ■ above, it is better to configure this device with metal pipes, etc., but in this case, leakage of high boiling point liquids, small chip parts being sucked in, remaining, etc. (The valve (shutter) must be configured to prevent this from occurring, and special measures are required.

■ If the structure is made of metal pipes etc. in the case of ■ above, the thermal conductivity of metal is higher than that of glass, so in order to give the high boiling point liquid a certain temperature gradient, special measures or a considerable amount of heat will be required compared to glass. Large equipment is required.

(D In order to automate the device of this method, it is essential to replace the glass container with a metal container, but this requires considerable ingenuity as shown in ■ and ■ above, and this method automation is difficult.

Problems to be Solved by the Invention The present invention solves the above-mentioned problems with the electrode parts of chip parts, reduces the surface area of the electrode part of chip parts, and smooths it to improve solder wettability and long-term storage. The first object of the present invention is to provide an electrode processing device that can improve soldering reliability. A second object of the present invention is to solve the problems of conventionally known electrode processing devices, and to eliminate mechanically moving parts (and to avoid aligning chip parts (even when they are inserted). , melting process is possible without the electrode parts of chip parts sticking to each other during melting, melting temperature can be controlled accurately, and electrode processing of chip parts can be done easily in mass production without using flux. Furthermore, a third object of the present invention is to eliminate the shortcomings of the electrode processing device previously proposed by the present inventors, that is, the defects related to safety; It is an object of the present invention to provide an electrode processing device that further improves productivity and can be easily automated.

Means for Solving the Problems In order to solve the problems mentioned above, the present invention provides a solution to the above problems, in which the high boiling point liquid inside the tank is filled with a high boiling point liquid such as oil. A heater is disposed on the outer periphery of the upper part to create a temperature gradient in the tank, and the tank has an upper part that is insulated from the high boiling point liquid in the tank, and a lower part with a window provided between the upper part and the upper part. The lower end of the cylinder is placed with the bottom of the tank floating, and above the cylinder a chip component with a film made of a low melting point metal or low melting point alloy is placed on the outermost layer of the electrode part. The chip parts are placed into the cylinder from the input part, and the processed chip parts subjected to electrode treatment in the cylinder are taken out from the high boiling point liquid in the tank.

Effect: According to this configuration, the film or layer made of a low melting point metal (low melting point alloy) is melted on the high temperature side of the high boiling point liquid in the container and cooled on the low temperature side, so surface tension acts during melting. , the surface area is small, and by cooling in this state, the surface area becomes extremely small compared to a low melting point metal film (low melting point alloy film) formed with a plating film, etc. This makes it possible to obtain chip parts that are smooth and have extremely low levels of adhesion of foreign matter and adsorption of gases during 1. In addition, it is possible to obtain chip parts with extremely low adhesion of foreign matter and gas during melting.3. Since these substances are also released, the outermost film itself becomes a clean film containing no impurities, and chip components with improved solder wettability and soldering reliability are obtained.And,
The electrode treatment simply involves moving the chip component from a high temperature section to a low temperature section in a high boiling point liquid, and can be easily carried out without using complicated equipment. It also melts in high-boiling liquids.

Cooling is performed, and since the electrodes of chip parts do not stick together on the low temperature side, it is possible to process chip parts by simply feeding them in large quantities in separate pieces without aligning them during electrode processing. Because the parts are in contact with liquid, heating and cooling are completed in a short time,
This makes it highly suitable for mass production. Furthermore, since the material is melted and cooled in a high boiling point liquid and has no chance of coming into contact with air, there is no fear that the surface of the electrode portion will be oxidized during melting. Also, performing melting processing in a liquid means that molten materials (low melting point metals, low melting point alloys, etc.)
Since the high boiling point liquid in contact with the metal has a high specific gravity and high viscosity, pressure is applied to the molten metal from the surrounding area, and the surface condition of the molten metal becomes smooth without prickling. , a product with a uniform thickness can be produced. In addition, by using oil such as natural vegetable oil or a liquid with a fluxing action such as glycerin as a high boiling point liquid, fluff or the like is not required, which simplifies the equipment and reduces the need for processed chip parts. Cleaning is also very easy.

Furthermore, since this electrode processing apparatus is of a cockless type, no cock operation (valve operation) is required when taking out processed chip components, and automation is easily possible. A glass handle (because it is metal, there is no limit to the input opening diameter, and it is possible to process large quantities without causing stickiness between the electrodes of the chip components being processed, and is expected to increase productivity.) Furthermore, since the tank is made of metal and there is no cock operation, there is less risk of high-temperature, high-boiling liquid spilling out, and safety is greatly improved.

In addition, since this device is constructed by inserting a cylinder into a tank, the assembly and maintenance of the device for taking out processed chips is simple, and automation is also easy. Furthermore, since the tube has a window that has the effect of heat insulation and heat radiation, it is impossible for the temperature gradient to change due to continuous production.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of an electrode processing apparatus for chip components according to the present invention.

In FIG. 1, numeral 7 denotes a chip component having the structure shown in FIG. 2, and the same reference numerals as in FIGS. 3 and 4 are given. For example, 27 is about 180cm tall! 450cm
It is a double box-shaped stainless steel tank with a diameter of 130 cm, and 18 is a high boiling point liquid placed in this tank 27, in this case coconut oil, which is a natural vegetable oil. 28 is a stainless steel cylinder, and has a window 29 in the middle. 30 is a heating device such as a mantle heater attached to the top of the cylinder 28.An air layer 32 is provided at the top of 28 and the outer periphery of the heater 30 by a stainless steel shielding plate 31.
is formed, thermally isolated from the outside and insulation maintained.

1228, the heater 30, and the shielding plate 31 are inserted from above into the box-shaped tank 27 filled with the high-boiling point liquid 18, and as shown in the figure, the cylinder 28 has a high-boiling point part whose upper surface is somewhat high. It is hidden so as to protrude above the liquid level of the tank 27, and its lower surface is located at a position somewhat higher than the bottom surface of the tank 27. Note that the bottom surface of the cylinder 28 is the tank 27.
It is also acceptable if the tube 28 is in contact with the bottom surface of the tube and the entire tube 28 can move up and down.

Here, 33 is the upper part inside the cylinder 28, 34 is the lower part inside the cylinder 28, and 35 is the part outside the shielding plate 31 and above the tank 27 mountain. The lower part 34 in the cylinder is located above and below the window 29.

36, 37, and 38 are a feeder, a line feeder, and a rotary chute, respectively, which feed the chip parts 7 from the liquid level of the tube 28.

2G is a chip component that has been subjected to electrode processing, and is accumulated in the removed steel 39 of the processed chip component.

40 is a high boiling point liquid 18 attached to the bottom of the tank 27.
Requirements for preventing coagulation 1B'SAm, 41 is that the tray is used to drain the liquid when the container is taken out from the tank 27.

Next, a method for treating the surface of the electrode portion of the chip component 7 using the apparatus shown in FIG. 1 will be described.

First, as a preparation, the high boiling point liquid in the upper part 33 of the cylinder is heated (to 250 to 280°C) by the heater 30. The high boiling point liquid 18 in the upper part 33 of the heated cylinder 28 has a small specific gravity, and does not convect with the lower temperature high boiling point liquid 18, which has a higher specific gravity, but only in the upper part. Further, the lower part of the tube 28 has a window 29. It is insulated from the upper part of the tube 28 by.

Therefore, inside the cylinder 28, the upper part 33 of the cylinder has a high temperature, and the lower part 34 of the cylinder has a normal temperature, so that a temperature gradient is formed and maintained.

At this time, the high boiling point liquid 18 in the portion 35 is thermally isolated from the heater 30 and the high-temperature cylinder upper part 33 by the shielding plate 31, so that it is kept at room temperature.

When the preparations are complete as shown in the figure, the chip parts 7 are fed into the hot upper part 33 of the cylinder using the feeder 36, line feeder 371, and rotary chute 38.

Since this rotary chute 38 always blows out air from within the chute, the inside of the chute will not be wetted by the vapor of the high boiling point liquid 18 and the chip component 7 will not be caught within the chute.

The chip component 7 used in this example is a square plate type chip resistor, and the structure of the electrode part is AgPd in the outermost layer, Ni in the middle layer, and Sn:Pb in the outermost layer (low melting point metal plating film).
=60: It has an electroplated film with a thickness of 7 to 10 μm.The melting point of the outermost layer material is 1
The temperature is 80-190°C.

The chip parts 7 thrown in by the rotary chute 38 are pieces)
The outermost layer of the electrode, Sn −
The Pb alloy plating film is melted and falls into a low temperature area with a temperature gradient, forming a high boiling point liquid 18 as coconut oil.
The molten part solidifies from the point at which the temperature of the chip part 26 passes through the part where the temperature is about 180''C or less, and the processed chip part 26 having the smooth electrode falls to the bottom of the tube 28.
It accumulates inside the take-out net 39. This retrieval net 39 is
Remove the processed chip component 26 from the level of the B liquid.

Note that if the cylinder 28 is movable up and down with respect to the bottom of the tank 27, the cylinder 28 may be moved up and down during electrode processing of chip components.
8 is lowered to the point where it touches the bottom of the tank 27, the processed chip parts 26 are stored at the bottom of the cylinder 28, and when taking out the chip parts, the cylinder 28 is lowered, and from there, a steel 39 or the like is used to remove the chip parts. This is to take out processed chip parts.

Here, since the processed chip components 26 accumulate at the bottom of the extraction net 39 or tube 28 at room temperature, the processed chip components 26
If 6 comrades touch each other, the electrodes will not stick together,
35 times when taking out! Since it is done from the i'i side, there is no such thing.

In addition, even when the chip parts 7 are continuously fed, if the temperature of the high boiling point liquid 18 in the lower part 34 of the cylinder is about to rise due to the falling chip parts 7 with heat, the temperature of the high boiling point liquid 18 in the lower part 34 of the cylinder will rise. High boiling point liquid 1 at room temperature in the upper part 35 inside the outside tank
8, the high boiling point liquid 18 in the lower part 34- of the cylinder has a low specific gravity, so the high boiling liquid 18 with low specific gravity escapes through the window 29, and the high boiling liquid 18 in the lower part of the tank outside the bay escapes from below the cylinder 28. flows in, and the liquid temperature in the lower part 34 of the cylinder is maintained at room temperature by the convection of the high boiling point liquid.

Here, the room temperature liquid in the tank always remains at room temperature because it has a much larger heat capacity than the chip components 7 that are hot and fall.

In this manner, the low melting point metal plating film of the chip component 7 is melted. Further, the processed chip component 26 that has been taken out can be turned into a finished product by simply washing it.

Here, in the above example, a case was explained in which coconut oil, which is a natural vegetable oil, was used as the high boiling point liquid, but this also includes natural animal oil, natural mineral oil, synthetic silicon oil, Materials that have the action of flux such as oil or glycerin can be used to have the same effect, and in addition to these materials, they can also be used to melt the molten material (low melting point metal film) in the electrode part of chip components. Any high-boiling liquid having a boiling point higher than the melting point can be used. In addition, an example was explained in which a mantle heater or the like was installed as a heater.
This may be done by heating the high boiling point liquid from inside using a closed type sheathed heater or the like.

The outermost layer of the electrode part of the chip component to be melted in the apparatus of the present invention is not limited to a low melting point metal plating film (low melting point alloy plating film) composed of electroplating or chemical plating, but can also be formed by thermal spraying or vapor deposition. There is no problem even if it is a low melting point metal film (low melting point alloy film) formed by the above-mentioned examples. In addition to solder, commonly used materials such as tin and even lead can be used.

The melting point of the low melting point metal film (low melting point alloy film) is 100
It is preferable that the temperature is ~550°C and the film thickness is 1 μm or more.

First, if the melting point is less than 100℃, after soldering,
The re-melted metal film may melt due to self-heating during use of the part, and if the temperature exceeds 550°C, the resistor and coating film will be destroyed and the performance as a chip part will not be maintained (there is a risk of In addition, if the film thickness is less than 1 μm,
A uniform film cannot be formed after heat treatment, reducing the reliability of soldering during mounting, and oxidation during storage. It has been confirmed through experiments that soldering is extremely easy if the film thickness is 8 to 15 μm.

Furthermore, the electrode processing device according to the present invention has a solderable metal film or alloy film made of iron or magnetic alloy, and the outermost layer is a layer coated with a low contact point metal paste or a low melting point alloy paste and dried. The present invention is also applicable to chip components having . In this case, it goes without saying that the melting point of the metal film (alloy film) that can be soldered as a base layer is higher than the melting point of the high boiling point liquid.Then, this low melting point metal (low melting point alloy) paste is applied. When a chip component having a dried layer as the outermost layer is subjected to electrode treatment using the apparatus of the present invention, a layer made of a low melting point metal (low melting point alloy) paste is more likely to be formed than a layer made of an electroplated film or a chemically plated film.
Soldering is advantageous in making the thickness, which is related to reliability, thick and uniform. In addition, low melting point metal (low melting point alloy) paste usually contains flux,
Because this flux dissolves in high-boiling liquids when melted,
It does not cause burn-in and does not impair its effectiveness. In a chip component having this structure, the thickness of the layer made of the low melting point metal (low melting point alloy) paste is preferably 3 μrn or more in a dry state, particularly 25 to 1 μrn.
A thickness of 00 μm remains.

Effects of the Invention As described above, the device for processing electrodes of chip components according to the present invention is constructed and has a number of characteristics. the layer is melted on the hot side of the high-boiling liquid in the container;
Because it is cold-rowed on the low-temperature side, surface tension acts during melting, reducing the surface area. By cooling in this state, a low-melting point metal film (low-melting point alloy film) formed with a plating film, etc. ), the surface area is extremely small (and the surface is smooth), making it possible to obtain chip parts with extremely low adhesion of foreign matter and adsorption of gas during storage. Alternatively, foreign substances and gases that were adsorbed and occluded inside the hollow are also released.
The outermost film itself becomes a clean film containing no impurities, and a chip component with improved solder wettability and soldering reliability is obtained. As for electrode treatment,
The chip component simply moves from the high-temperature part to the low-temperature part in the high-boiling liquid, and can be easily implemented without using complicated equipment. In addition, since melting and cooling are performed in a high-boiling liquid in this way, and the electrodes of the chip parts do not stick together on the low-temperature side, the chip parts do not have to be aligned during electrode processing, and are disassembled in large quantities. Processing can be done simply by placing the chip in a liquid, and since the chip components are in contact with the liquid, heating and cooling can be completed in a short time, making it highly suitable for mass production. Furthermore, it melts in high boiling point liquids.

Since cooling is performed and there is no opportunity for contact with air, there is no fear that the surface of the electrode portion will be oxidized even when melted. In addition, the key to performing melting treatment in a liquid is that the specific gravity of the high boiling point liquid in contact with the molten material (low melting point metal, low melting point alloy, etc.) is high compared to air, and the viscosity is also high. Therefore, pressure is applied to the molten metal from the surroundings,
The surface condition of the molten metal becomes a smooth surface without any edging, and the thickness is also uniform. In addition, by using oils such as natural vegetable oils and liquids with fluxing action such as glycerin as high boiling point liquids,
No flux is required, which simplifies the equipment and greatly facilitates cleaning of the processed chip parts.

Furthermore, the effects of the present invention are listed below.

■ Since chip parts can be input without arranging them, they can be processed with the same equipment regardless of their size. It is also possible to mix and process chip components of different sizes.

■ Since the process can be performed without using flux, cleaning of chip parts is easy, and there is no burning of flux, resulting in a clean finished product.

■ Because the heat medium is a high-boiling point liquid, temperature control is also highly accurate.Since the high-boiling point liquid and chip components are in contact, heat conduction is fast, and melting and solidification processes can be performed in a short time. Highly reliable. In other words, there is no melting failure.

■ Since the high-boiling point liquid has a temperature gradient, processed chip parts can be stored in a pile in the low-temperature section at once, and can be taken out all at once, greatly simplifying the removal work.

■ By selecting the type or specific gravity of the high boiling point liquid, the passage time of the chip component in the liquid can be changed. Furthermore, by changing the temperature gradient of the high boiling point liquid, the specific gravity changes, so the passage time of the chip component through the liquid can be changed as well. Thereby, even if the type or size and shape of the film or layer made of a low melting point metal or low melting point alloy of the chip component changes, it can be easily handled.

■ Since it has a structure without a cock, there are no quality abnormalities caused by chip parts getting caught or stuck.

■ Since the structure is without a cock, there is no risk of high-temperature, high-boiling liquid leaking due to improper cock operation or lack of sealing of the cock.

■ It is possible to have a metal tank structure, and it is shock and
It has high strength against stress, etc., and there is little risk of high boiling point liquid spilling due to container breakage, making it highly safe.

Since it can be made of metallic material, there is no limit to the size of the input port for chip components, and there is no possibility of the electrodes of chip components sticking together during processing (this makes it possible to perform high-volume, high-speed processing. , it is possible to expand productivity.

[Phase] Since there is no cock, it is easy to automate the extraction work, and it is also easy to connect to the cleaning work of electrode-treated chip parts and create a line.

■ Since this device is constructed by inserting a cylinder into the tank, the configuration 2 of the device for taking out processed chip parts is
Easy to assemble and maintain.

・j◇ The window in the tube insulates the bottom of the tube from the top of the tube, and the window also prevents the temperature rise at the bottom of the tube during continuous production due to the hot chip parts falling from the top of the tube. This is suppressed by liquid convection to the outside, and the cooling effect in the lower part of the cylinder is maintained without the use of a special cooling surface, making it possible to continuously process large quantities of chip components at high speed.

<■ The configuration of this device is simple and can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the electrode processing device for chip components according to the present invention, FIG. 2 is a sectional view showing a square plate type chip resistor which is a type of chip component, and FIG. 3 is a conventionally known FIG. 4 is a schematic diagram illustrating an example of an apparatus for processing electrodes of chip components, as previously proposed by the present inventors. 7... Chip parts, 18... High boiling point liquid, 26... Processed chip parts, 27...
...Tank, 28...Tube, 2...Window, 30...Heater, 31...Shielding plate, 32... Air layer, 33... Upper part of the cylinder, 34... Lower part of the cylinder, 36... Feeder, 37... Line feeder, 38...・・・
Rotating chute, 39... Retrieval net. Name of agent: Patent attorney Shigetaka Awano and 12 others! Diagram

Claims (4)

[Claims] (1) A heater for creating a temperature gradient in the high boiling point liquid in the high boiling point liquid in the tank filled with a high boiling point liquid such as oil is disposed at the upper outer periphery of the tank, and The lower end of the cylinder, which has an upper part that is insulated from the high boiling point liquid inside the tank and a lower part that is arranged with a window between the upper part and the bottom of the tank, is placed above the cylinder. A charging section is provided in which a chip component having a film made of a low melting point metal or a low melting point alloy is provided on the outermost layer of the electrode section is inserted into the cylinder. An electrode processing device for chip parts, characterized in that the processed chip parts are taken out from a high boiling point liquid in a tank. (2) A heater for creating a temperature gradient in the high boiling point liquid in the high boiling point liquid in the tank filled with a high boiling point liquid such as oil is disposed on the upper outer circumference of the tank, and A cylinder having an upper part insulated from the high boiling point liquid inside the tank and a lower part with a window provided between the upper part and the cylinder is arranged so as to be movable up and down with respect to the bottom of the tank. A charging section is disposed above the electrode section for charging a chip component having a film made of a low melting point metal or a low melting point alloy on the outermost layer into the cylinder, and the chip component is charged into the cylinder from the charging section, An electrode processing device for chip parts, characterized in that a processed chip part subjected to electrode processing in a cylinder is taken out from a high boiling point liquid in a tank. (3) The chip component according to claim 1, which uses any one of natural vegetable oil, natural animal oil, natural mineral oil, synthetic silicone oil, or glycerin as the high boiling point liquid. Electrode processing equipment. (4) The electrode processing device for chip components according to claim 1, which uses a mantle heater that heats from the outside or a closed-type sheathed heater that heats from the inside as the heater.