JP2001205429A - Solder melting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable air temperature to be raised to a desired high temperature by efficiently heating air passing along an outer peripheral side of a heater. SOLUTION: A coil-shaped member 15 is interposed between the heater 11 and an external cylinder 9 outside the heater 11 to generate spiral flow in the air passing through an air passage 12. The coil-shaped member 15 is force- fitted and held in an inner peripheral surface of the external cylinder 9 and is arranged with a minute space with the heater 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder melting method used when an electronic component such as an IC soldered to a substrate is removed from the substrate or when a new electronic component is attached to the substrate after the removal. About the vessel.

[0002]

2. Description of the Related Art For example, an air supply source is provided in a grip portion as a solder melter used to remove electronic components such as ICs from a printed circuit board or to mount electronic components such as ICs. A hollow portion through which the air supplied from the air passage and the power supply cord are provided, and a heater electrically connected to the power supply cord at a tip end side of the grip portion, and an air passage around the heater so as to surround the heater. Is known, and a nozzle for discharging air heated by a heater is attached to the end of the outer cylinder. According to this solder melter, the heated air discharged from the nozzle at the tip is blown to the soldered portion fixing the electronic component to the printed circuit board, so that the soldered portion is melted in a very short time. The electronic component can be easily removed from the board by using the method described above. When the electronic component is mounted on the printed circuit board, the cream solder attached to the printed circuit board is melted again, and a lead or the like extending from the electronic component is assembled at a predetermined position using the melted solder.

[0003]

According to the above-described conventional solder melting machine, since the soldering portion is heated by hot air, there is no uneven heating compared to the method of directly heating with a soldering iron. Although there is an advantage that the electronic component can be removed without peeling off the pattern, there are the following problems. That is, when the air supplied from the air supply source is passed through the air passage formed between the heater and the outer cylinder outside the heater, the heater is heated by the heater. There is a problem that the temperature of the heated air cannot be increased so much. In particular, when there are many soldering parts and a large amount of hot air must be supplied, the amount of air supplied to the soldering parts must be increased, and in this case, if the amount of air supplied increases, the air temperature will drop. As a result, it took a long time to melt the soldered portion, and in extreme cases, the solder could be melted only partially.

The present invention has been made in view of the above circumstances, and has as its object to efficiently heat air passing through the outer peripheral side of a heater and reduce the temperature of the air to a desired high temperature. It is an object of the present invention to provide a solder melter which can be increased up to a maximum.

[0005]

The present invention has the following features in order to solve the above-mentioned problems. That is,
The solder melter according to claim 1 is provided with a hollow portion for passing air supplied from an air supply source and for passing a power cord in the grip portion, and a distal end side of the grip portion,
A heater electrically connected to the power cord, and an outer cylinder that forms an air passage around the heater so as to surround the heater are attached, and air heated by the heater is provided at a tip of the outer cylinder. A nozzle is attached, and the heated air discharged from the nozzle is sprayed on a soldered portion fixing the component to the substrate, so that a solder melting device for melting the soldered portion is provided.
A coil-shaped member for generating a spiral flow in the air passing through the air passage is interposed between the heater and the outer cylinder outside the heater. In the solder melter,
When the air supplied from the air supply source passes through the air passage between the heater and the outer cylinder outside the heater, a spiral flow is generated by the coil-shaped member and flows as it is toward the nozzle at the tip. As described above, the air in the portion in contact with the heater becomes a helical flow to form a turbulent flow, and accordingly, the heat exchange rate with the heater is improved, and the air is efficiently heated. Further, as described above, since the air in the portion in contact with the heater forms a spiral flow, the contact time with the heater increases, and the substantial contact area with the heater also increases. This also improves the heat exchange rate with the heater, and heats the air to a desired high temperature.

According to a second aspect of the present invention, the heater is a ceramic heater. In the solder melter, since a ceramic heater is used as a heater, a heating element having an arbitrary shape can be obtained, and the durability is excellent.

According to a third aspect of the present invention, in the solder melter, the coil-shaped member is press-fitted and held on an inner peripheral surface of the outer cylinder. In the solder melting device, by holding the coil-shaped member on the inner peripheral surface of the outer cylinder, the coil-shaped member can be held with an appropriate gap from the heater. For this reason, the heat capacity of the heater can be reduced, the heater can be heated in a short time, and the replacement work of the heater becomes easy, which is advantageous from the viewpoint of maintenance.

According to a fourth aspect of the present invention, the coil-shaped member is disposed on an outer peripheral surface of a heater portion of the ceramic heater. In the solder melter, the air supplied from the air supply source generates a spiral flow outside the heater portion of the ceramic heater by the coil-shaped member. That is, a helical flow is generated in a portion where air is to be heated, and air can be heated without waste in energy.

According to a fifth aspect of the present invention, in the solder melter, the coil-shaped member is a heating coil.
In the solder melter, a coil-shaped member that generates a spiral flow in air supplied from an air supply source is configured by a heating coil. In other words, the coil has a function of generating a spiral flow to improve a heat exchange rate with the heater,
The coil itself performs both functions of heating the air.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a solder melter showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a grip portion gripped by an operator. The grip portion 1 is hollow, and the proximal end of the inner hollow portion 2 is connected to a flexible tube. The hollow portion 2 in the tube and grip portion 1 allows air supplied from an air pump 5 serving as an air supply source housed in a box-shaped solder melter main body 4 to pass therethrough, and a power cord 6 and a not-shown power cord. Functions as a part for passing the signal code.

A proximal end of a substantially cylindrical connecting member 7 having a flange is attached to a distal end of the grip portion 1. The connecting member 7 has a radial rib at a distal end thereof. A piece 8 having a communication hole formed between the ribs is fitted inside, and an outer cylinder 9 is attached to a tip of the piece 8 by a nut 10 screwed to the connecting member 7.

A heater 11 electrically connected to the power cord 6 is disposed in the outer cylinder 9 so as to be supported by the piece 8. The heater 11 is a ceramic heater,
About one-third of the front end of the substantially entire length is a heater portion 11a. An air passage 12 is formed between the heater 11 and the outer cylinder 9 arranged so as to surround the outer periphery thereof. A nozzle connection portion 13 is provided at a tip of the outer cylinder 9, and a nozzle 14 for discharging the air heated by the heater 11 is attached to the nozzle connection portion 13.

A coil-shaped member 15 is provided between the heater 11 and the outer cylinder 9 outside the inner cylinder 9a of the outer cylinder 9.
It is held and arranged in a state where it is pressed into. The coil-shaped member 15 is positioned and fixed outside the heater portion 11a of the heater 11.

A motor (not shown) for driving the air pump 5 is provided with air volume adjusting means 16 and the rotation speed of the air pump 5 is adjusted by adjusting the air volume adjusting means 16 appropriately. It has become.
Reference numeral 17 denotes a temperature adjusting means.
7 is appropriately adjusted, the temperature of the heater 11,
As a result, the temperature of the hot air discharged from the nozzle 14 is adjusted.

Next, the operation of the above-described solder melter will be described. The operator points the tip of the nozzle 14 to a portion to be melted in a soldering portion for fixing an electronic component such as an IC to the printed circuit board. Before or after the operation, a main switch (not shown) is turned on, and the temperature and air volume of the hot air discharged from the nozzle 14 are determined by the temperature adjusting means 16 and the air volume adjusting means 17 according to the solder portion to be melted. A motor (not shown) is driven based on the ON operation of the main switch, and the air pump 5 linked to the motor operates. Then, air is sent from the air pump 5, and the air passes through a tube (not shown) and reaches the inside of the grip portion 1, from which the heater 1 is heated.
It passes through an air passage 12 formed between 1 and the outer cylinder 9. At this time, the air passing through the air passage 12 is heated by the heater 11.

Here, the air passing through the air passage 12 flows toward the nozzle 14 at the tip while generating a spiral flow by the coil-shaped member 15. As described above, the air in the portion of the heater 11 particularly in contact with the heater portion 11a forms a turbulent flow due to the spiral flow, and accordingly, the heat exchange rate with the heater 11 is improved and the air is efficiently heated. Is done. Further, since the air in the portion in contact with the heater 11 has a spiral flow, the time for the air to contact the heater 11 increases, and
The substantial contact area with the heater 11 also increases. In this sense, the heat exchange rate with the heater 11 is further improved, and the air is heated to a desired high temperature.

[0017] Therefore, the air can be heated to a temperature which could not be reached conventionally, and the soldered portion can be melted in a shorter time, thereby improving workability. Further, as described above, since the coil-shaped member 15 is disposed in the air passage 12 between the heater 11 and the outer cylinder 9, the heater 11 may be arranged at a position eccentric to the outer cylinder 9. In this case, the heater 11 can be forcibly positioned at the axial center position (radial center position) of the outer cylinder 9 by the coil-shaped member 15, and from this point, the hot air discharged from the nozzle 14 changes in temperature. And uniformity. Further, as shown in FIGS. 2 and 3, if a cross portion 15 a extending in a direction crossing the air passage 12 is provided at the tip of the coil-shaped member 15, the heater 11 can be moved radially with respect to the outer cylinder 9. The position in the axial direction is also possible without being limited to the above, and the assemblability is excellent.

In this embodiment, since a ceramic heater is used as the heater 11, a heating element having an arbitrary shape can be easily obtained, and the durability is excellent. Further, in this embodiment, since the coil-shaped member 15 is arranged in a state of being pressed and held inside the outer cylinder 9, the coil-shaped member 15 is arranged with an appropriate gap from the heater 11. be able to. Therefore, the heater 11
The heat capacity of the heater 11 can be reduced, the heater 11 can be heated in a short time, and the heater 11 can be easily replaced, which is advantageous in terms of maintenance.

In the above embodiment, the coil-shaped member 15 is used for generating a spiral amount in the air passage 12 and for positioning the heater 11 in the radial and axial directions. If the coil-shaped member 15 is constituted by a heating coil and a current is supplied to the coil, the coil-shaped member 15 can be further used for heating, and the air flowing through the air passage 12 can be further reduced. Heating can be performed efficiently.

In the above embodiment, only one nozzle 14 is connected to the outer cylinder 9. However, the present invention is not limited to this, and a plurality of nozzles 14 may be connected to one outer cylinder 9. A plurality of pairs of one outer cylinder 9 and one nozzle 14 forming a pair may be provided.

[0021]

As described above, according to the present invention, when the air supplied from the air supply source passes through the air passage between the heater and the outer cylinder outside the heater, the air is spiraled by the coil-shaped member. Flow to the nozzle at the tip as it is,
As described above, since the air in the portion in contact with the heater becomes a helical flow and forms a turbulent flow, the heat exchange rate with the heater is improved accordingly, and the air can be efficiently heated. Further, as described above, since the air in the portion in contact with the heater forms a spiral flow, the contact time with the heater increases, and the substantial contact area with the heater also increases. From this, the heat exchange rate with the heater is further improved, and the air can be heated to a desired high temperature. Further, the heater can be positioned in the radial direction and the axial direction with respect to the outer cylinder by the coil-shaped member, and uniform hot air with little temperature change can be obtained, and the assembling property is excellent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a solder melter showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a part of the solder melter according to the first embodiment.

FIG. 3 is a perspective view of a coil-shaped member used in the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grip part, 2 Hollow part 4 Solder melter main body 6 Power cord 9 Outer cylinder 11 Heater 11a Heater part 12 Air passage 14 Nozzle 15 Coiled member 16 Air volume adjusting means 17 Temperature adjusting means

Claims (5)

[Claims] 1. A hollow portion for passing air supplied from an air supply source and passing a power cord is provided in a grip portion, and a heater electrically connected to the power cord at a distal end side of the grip portion. And an outer cylinder that forms an air passage around the periphery of the heater so as to surround the heater, and a nozzle that discharges air heated by the heater is attached to a tip of the outer cylinder. By blowing the heated air that is discharged onto the soldering part that fixes the component to the board,
In the solder melting device for melting the soldering portion, a coil-shaped member that generates a spiral flow in the air passing through the air passage is interposed between the heater and the outer cylinder outside the heater. Solder melter. 2. The solder melter according to claim 1, wherein said heater is a ceramic heater. 3. The solder melter according to claim 1, wherein the coil-shaped member is press-fitted and held on an inner peripheral surface of the outer cylinder. 4. The solder melter according to claim 3, wherein said coil-shaped member is disposed outside a heater portion of said ceramic heater. 5. The solder melting device according to claim 1, wherein the coil-shaped member is a heating coil.