JPH04191049A - Burning device for cubic matter printer - Google Patents

Abstract

PURPOSE:To remove vapor in gas with high efficiency and absorb all dewdrops for removing it by connecting, to a stage after a booster of a fuel gas supply system for burning treatment, a moisture absorber having a container body which seals a housing bag sealing a moisture absorbent for absorbing moisture instantaneously and maintaining it. CONSTITUTION:A moisture absorber 6 is arranged at a stage after a booster 5. The moisture absorber 6 is constituted of porous material. A moisture absorbent 6e in a packed state sealed in a housing bag 6f having water penetrating property is inserted in a container body 6a and laid on a partition stamp 6d and sealed in the container body 6a being capped by a cap 6g. The moisture absorbent 6e is made of special water absorbing polymer, which swells hygroscopically instantaneously when it contacts with water so as to swell to a powdered volume and has a function to maintain the absorbed water because it dissolves in water only a little. Accordingly, because of passage of gas through the water absorber 6, the moisture absorbent 6e provides a dehumidifying effect of 10-30% to make the humidity approximate to the room humidity. Also, dewdrops are removed 100% being absorbed by the moisture absorbent 6e.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a method for facilitating printing on the surface of electronic components such as semiconductor devices and other relatively small three-dimensional articles, and for increasing the adhesion strength of printing. This invention relates to a burning device that performs pretreatment.

<Conventional technology> In a three-dimensional article printing machine (marking system) that prints the product name, model number, etc. on the surface of three-dimensional articles such as electronic parts, impurities such as oil and fat films and dust are removed from the surface of the printed article before printing. Cleaning with volatile solvents and burning with flames have been known as means to facilitate this and increase the adhesion strength of the print. However, as the amount of chemicals that cannot be imprinted on mold materials for electronic components has increased year by year, it has become difficult to maintain the adhesion strength of printing by cleaning with solvents, and environmental pollution regulations have made it difficult to maintain the adhesive strength of prints after cleaning with solvents. Due to the high cost of waste liquid treatment, in recent years the method of burning with flame has mainly been adopted.

When grilling with this flame, it is known that a clean method that does not emit smoke is to burn hydrogen gas. When hydrogen gas is used as fuel, hydrogen gas generation means include a method of electrolyzing water using a caustic soda aqueous solution as a catalyst, and a method of electrolyzing pure water using an ion exchange membrane.

<Invention or Problem to be Solved> The method of electrolyzing pure water to generate hydrogen is low cost for companies that handle pure water, such as semiconductor manufacturing industries, and it is possible to use pure water for semiconductor manufacturing as is. It's convenient to be able to do it. However, hydrogen gas and oxygen gas obtained by electrolysis contain moisture, and even if there is a trace amount of moisture, if it is released from the combustion nozzle, the flame temperature will drop momentarily and sufficient combustion will occur. There is a problem that no effect is obtained, and as a result, the printed ink tends to peel off.

In addition, when the gas generated from the gas generator passes through the piping, it is cooled by the outside air temperature and condenses on the inner wall of the piping, and some of the dew condenses or combines to form water droplets and stays in the lower part of the piping, and these condensed water droplets When the gas is ejected from the nozzle during pressure-feeding, it evaporates and scatters into the atmosphere due to the burning flame, or at this time, the flame temperature changes as mentioned above, or it adheres to the conveyance path of the three-dimensional object and causes discoloration and rust. There is a problem with this.

Conventionally, dehumidification methods have been used to remove moisture from this gas, in which water vapor is liquefied by cooling and the resulting water droplets are collected, but this method requires complicated equipment and has the disadvantage of increasing costs.

Therefore, the present invention provides a burning method for three-dimensional article printing machines that can remove both water droplets and water vapor in gas with high efficiency, is easy to handle, does not require any effort on the part of the user, and is inexpensive in both manufacturing and running costs. The problem to be solved is to provide equipment.

Means for Solving the Problems> The present invention provides a burning device for a three-dimensional article printing machine that burns out a flame by gas combustion on the surface of a three-dimensional article in a pre-process of printing on a small three-dimensional article such as an electronic component. In,
between the booster and the flow meter in a gas fuel supply system that guides the gas generated by the gas generator to the nozzle via a bubbler, a booster, a flow meter, and a flashback prevention filter;
A moisture absorber is inserted and connected, and this moisture absorber is connected to a main container having a gas inlet and a gas outlet, and when it comes into contact with moisture, it instantly absorbs water and swells, gradually changing from a powder to a fine granule. , and is characterized by comprising a moisture absorbent that retains absorbed water, and a water permeable storage bag in which the moisture absorbent is sealed and enclosed in the main container so as to be freely removable.

<For use> Although the gas generated by the gas generator passes through the bubbler and booster and is somewhat cooled and dehumidified, its temperature is only slightly lower than when the gas generator outputs.
When fed from the booster through the piping tube,
The gas inside the piping tube is further cooled by the outside temperature and condenses on the inner wall of the tube, and some of the dew condenses or combines to form water droplets that stay at the lower part of the piping tube and are gradually transported by the gas that is pumped through the tube.

When this gas passes through the moisture absorber, the moisture absorbent has a dehumidifying effect of 10 to 30%, resulting in a state close to indoor humidity.In addition, the moisture absorbent absorbs and removes 100% of the condensed water droplets. do. After this dehumidified gas is in a good condition, it passes through a flowmeter and a flashback prevention filter, and then is combusted and injected from a nozzle to burn away oil, fat, and dust on the surface of the three-dimensional object to be printed.

Since the gas sent to this nozzle has been dehumidified to the level of room humidity by a moisture absorber, there is almost no change in flame temperature due to moisture in the gas, increasing the adhesion strength of printing. Moreover, since all the condensed water droplets are absorbed by the moisture absorber, discoloration and rust do not occur on the article conveyance path.

<Embodiment> FIG. 1 shows the configuration of a gas fuel supply system of a burning device for a three-dimensional article printing machine according to an embodiment of the present invention, in which a hydrogen/oxygen mixed gas generator 1 is configured as an ion exchange membrane type, Pure water is electrolyzed using an electrochemical cell that has an anode and a cathode made of platinum group metals integrally bonded to both sides of an ion exchange membrane to generate hydrogen and oxygen.
Generates a saturated gas of a mixture of hydrogen and oxygen at a temperature of approximately 50°C and high humidity (approx. 98% humidity).

The gas generated from this gas generator 1 is sent to a bubbler 3 via a first backflow water recovery tank 2, and in this bubbler 3, water is removed by bubbling it into internal purified water (pure water). It becomes a gas with about 90% humidity. Furthermore, it is sent to the booster 5 via the second backflow water recovery tank 4,
The gas passes through the methanol aqueous solution in the booster 5 and is cooled, becoming a gas with a humidity of 75 to 79%. Further, although this gas is somewhat cooled and dehumidified by the bubbler 3 and the booster 5, its temperature is only slightly lower than that at the time of output from the gas generator 1. Therefore, when being fed through a piping tube made of a special rubber tube or silicone tube, the gas inside the piping tube is further cooled by the outside temperature and condenses on the inner wall of the tube, and some of it condenses or combines to form water droplets. It temporarily stays in the lower part of the piping tube and is gradually sent by the gas that is pumped through the tube.

A moisture absorber 6, which is the gist of the present invention, is disposed downstream of the booster 5. This moisture absorber 6 has a main body container 6
A gas port 6b and a gas outlet 6c are provided on the side surface of the lower edge and the side surface of the upper edge, respectively, and a partition rod 6d is installed slightly above the gas port 6b inside the main container 6a. Then, the moisture absorbent 6e, which is in the form of a pack and is sealed in a storage bag 6f made of a porous material and has water permeability, is inserted into the container body 6a and placed on the partition rod 6d.
Moreover, it is sealed in the main container 6a by closing the main container 6a with the cap 6g. The moisture absorbent 6e has the function of changing from a powder to a solid state by absorbing moisture, and then changing to a fine particle (snow-like) as the moisture absorption progresses further. That is, this moisture absorbent 6e is a special water absorbing polymer characterized by polyacrylic acid soda (CH2CHCOONa), and when it comes into contact with water, it instantly absorbs water and swells to a fine powder volume, and has extremely low dissolution in water. It has the function of retaining water absorbed by the water.

Therefore, by passing the gas through the moisture absorber 6,
The moisture absorbent 6e obtains a dehumidifying effect of 10 to 30%, resulting in a state almost equal to indoor humidity, and the moisture absorbent 6e absorbs and removes 100% of the condensed water droplets.

After this dehumidified gas is in good condition, it passes through the flow meter 7 and anti-backfire filter 8, and is then combusted and injected from the nozzle 10 at the tip of the nozzle holder 9 to eliminate oil and fat on the surface of the three-dimensional object to be printed. Disappear dust. This nozzle 10
Since the gas sent to the printer is dehumidified to the level of indoor humidity by the moisture absorber 6, the flame temperature hardly changes and the adhesion strength of the print is increased and maintained at the required value, thereby preventing the occurrence of printing defects. can. In addition, since all of the condensed water droplets are absorbed by the moisture absorber 6, no discoloration or rust occurs on the article conveyance path.

Further, a hydrogen gas alarm 11 is disposed near the nozzle 10. FIG. 2 shows the arrangement of the hydrogen gas alarm 11, in which the same parts as in FIG. 1 are given the same reference numerals. An opening 12a is formed in the top surface of the safety cover 12 that covers the upper part of the nozzle 10.
A hydrogen gas sensor lla of the hydrogen gas alarm 11 is arranged and attached at a position above 2a. This hydrogen gas sensor lla is a hydrogen gas detection dedicated sensor with high precision selectivity that detects only hydrogen gas using a constant potential electrolysis method. It is completely different from the catalytic combustion type and the hot wire type semiconductor type, which react, and always reliably detects only hydrogen gas, regardless of the environment, regardless of other combustible gases.

When hydrogen gas leaking from the opening 12a or hydrogen gas concentration reaching 1/100 of the lower explosive limit is detected through the hydrogen gas sensor 11a, a buzzer sound is emitted from the speaker 11b to notify that ventilation is required, and an alarm is issued. The display light emitting diode 11c blinks. This alarm display will automatically return when the hydrogen gas concentration decreases due to ventilation.

Note that the opening 12a may not be provided in the safety cover 12, and the hydrogen gas sensor lla may be placed in the upper corner of the safety cover 12, as shown by the dashed line in FIG.

<Effects of the Invention> As described above, according to the burning device for a three-dimensional article printing press of the present invention, a moisture absorbent that instantly absorbs moisture and retains the moisture is provided at the downstream stage of the booster of the gas fuel supply system used for the burning process. By inserting and connecting a moisture absorber made by enclosing a sealed storage bag inside the main container, water vapor in the gas can be removed with high efficiency, and all condensed water droplets can be absorbed and removed.

Therefore, the adhesion strength of printing can always be maintained at a required value, printing defects can be reliably prevented, and the article conveyance path can be prevented from discoloring and rusting.

In addition, when the moisture absorbing effect of the moisture absorbent decreases, the storage bag that seals the moisture absorbent can be replaced by removing the cap from the main container, and since it is easy to handle, it does not require any effort on the user's part. Moreover, it has the advantage that both manufacturing cost and running cost are low.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a cutaway side view of a portion thereof. 1...Gas generator 3... Bubbler 5...Booster 6...Moisture absorber 6a...Main container 6b...Gas inlet 6c...Gas outlet 6e...Moisture absorbent 6f...storage bag 7...Flow meter 8...Backfire prevention filter 10... Nozzle

Claims (1)

[Claims] (1) In a burning device for a three-dimensional article printing machine that incinerates the surface of a three-dimensional article with a flame caused by gas combustion in the pre-process of printing on a small three-dimensional article such as an electronic component, the gas generated by the gas generator is used in a bubbler. , a moisture absorber is inserted and connected between the booster and the flow meter in a gas fuel supply system that leads to the nozzle via a booster, a flow meter, and a flashback prevention filter, and this moisture absorber is connected to the gas inlet. When it comes into contact with water, it instantly absorbs water and swells, gradually transitioning from a powder to a fine granule.
A burning device for a three-dimensional article printing machine, comprising a moisture absorbent that retains absorbed water, and a water-permeable storage bag in which the moisture absorbent is sealed and enclosed in the main container so that it can be taken in and out.