JPH0318469A - Air reflow device - Google Patents

Abstract

PURPOSE:To allow a uniform reflow soldering only by the hot wind heating by providing a cotton-like flow regulating material which has heat resistance and air permeability and is packed between a pair of perforated plates on the hot wind supply opening side of a hot wind generator. CONSTITUTION:The air pressurized and supplied from a blower of the hot wind generator 12 via an air feed port 16 into a box-shaped body 16 is not so much regulated in flow in the first perforated plate 20 and collides vigorously against a heater 22. Since turbulence is thereby easily generated around the heater 22, the heat transfer rate the from heater 22 to gas is good. The high temp. air flow heated by the heater 22 is so regulated in flow as to attain a uniform flow velocity and heat distribution over the entire surface of the hot wind supply opening 26 in the stage of transmitting the cotton-like flow regulating material 25 packed between a pair of the perforated plates 23 and 24 and is blown out of the hot wind supply opening 26 toward a work transporting line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an air reflow device used for reflow soldering.

(Prior Art) As shown in Japanese Unexamined Patent Publication No. 61-289697, there is a method that performs reflow soldering by using both an infrared heating method using an infrared heater and a hot air heating method using hot air.

(Problems to be Solved by the Invention) In the infrared heating method, as shown in FIG. 7, there is a large variation in the temperature of the heated workpiece due to the difference in the infrared absorption rate of the workpiece. On the other hand, in the hot air heating method, the heating temperature also varies depending on the arrangement of the hot air heating heater and the like. In the conventional example, hot air circulation systems are provided above and below the workpiece conveyance line in order to uniformly heat the workpiece, but this structure tends to make the apparatus large.

An object of the present invention is to provide a compact air reflow device that can perform uniform solder flow soldering using only hot air heating.

[Structure of the invention]

(Means for Solving the Problems) The invention of claim 1 is an air reflow apparatus that performs reflow soldering using high temperature of hot air, in which a hot air generator 12 or 13 is opposed to a workpiece conveyance line 11, The container 12 or 13 has a box-shaped main body l5, an air supply port 16 provided on the opposite side of the box-shaped main body l5 from the work transfer line l1, and an air supply port 16 provided on the work transfer line side of the box-shaped main body l5. A hot air outlet 26, a heater 22 provided inside the box-shaped main body 15, and a pair of perforated plates 2 provided closer to the hot air outlet than the heater 22.
3. 24, and this pair of perforated plates 23. A cotton-like straightening material 25 having heat resistance and breathability is filled between 24 and 24.
It is characterized by having the following.

According to a second aspect of the invention, in the air reflow apparatus according to the first aspect, a pair of hot air generators 12 are provided above and below the workpiece conveyance line 11. 13 and preheating zone forming member 45. 46, a hot air duct 47 is formed around the workpiece transfer line 1l.

According to a third aspect of the invention, in the air reflow apparatus according to the second aspect, a pair of hot air generators 12. 13 is arranged, and a hot air suction port 54. 55.58 are provided, and this hot air suction port 54. 55. 58 is communicated with an inlet port 64 of a blower 63, and an outlet port 66 of this blower 63 is connected to the hot air generator 12.58. 13, and is connected to the air supply port 16 of No. 13.

The invention according to claim 4 is the air reflow apparatus according to claim 2 or 3, in which a relatively low temperature air is provided on the workpiece unloading side of the hot air duct 47 and above or below the workpiece transport line +1 toward the workpiece loading side. A nozzle 72 for spouting gas is provided.

(Function) In the invention of claim 1, the gas supplied under pressure from the air supply port l6 to the inside of the box-shaped body l5 is heated by the heater 22,
The high temperature gas flow is transmitted through a pair of perforated plates 23. At the stage of passing through the cotton-like straightening material 25 between 24 and 24, the flow is rectified so that the flow velocity and heat distribution are uniform over the entire surface of the hot air outlet 2G, and it is blown out from this hot air outlet 26 to the workpiece conveyance line 11. Reflow soldering is performed using high-temperature hot air.

According to the second aspect of the invention, a pair of hot air generators 12. The hot air compressed during step 13 acts efficiently and heats the workpiece W efficiently.

According to the third aspect of the invention, the hot air generator 12. 13 to hot air suction ports 54, 55 on the workpiece loading side. The workpiece W is preheated by the hot air flowing toward the workpiece 58 (a headwind for the workpiece), and the workpiece W whose temperature has been raised by this preheating is heated by the pair of hot air generators 12.
．． Reflow soldering is performed by hot air directly jetted from 13.

According to the fourth aspect of the invention, if necessary, the hot air blown onto one side of the workpiece W from the hot air generator 13 on one side is blocked by relatively low-temperature gas ejected from the nozzle 72, so that the workpiece W is not heated to a high temperature. . The hot air whose direction is changed to the workpiece loading side by the gas injected from the nozzle 72 is used to preheat the workpiece W.

(Example) Hereinafter, the present invention will be explained in detail with reference to the example shown in FIGS. 1 to 6.

As shown in FIG. 4, a pair of hot air generators 12 are placed above and below the workpiece conveyance line l1.
13 are facing each other.

As shown in FIGS. 1 to 3, this hot air generator 1
2. 13, a box-shaped main body l5 is provided inside an outer frame l4, two air supply ports 16 are provided on the upper surface of this box-shaped main body 15, and an air supply pipe 17 is inserted into each of the air supply ports l6, This air supply pipe! A substantially square baffle plate l8 attached to the box-shaped main body 15 is provided at the inner end opening of the box-shaped main body 15, facing each other with a gap l9 therebetween. 20 is provided by a mounting plate 2l, a large number of quartz glass tube heaters 22 are provided below this perforated plate 20, and a pair of perforated plates 2 are provided below this heater 22.
3. A cotton-like straightening material 25 having heat resistance and air permeability is filled between the spaces 24 . The lower surface (workpiece transfer line 11 side) of the box-shaped main body 15 is opened and serves as a hot air outlet 26 .

The inside of the upper plate and peripheral plate forming the box-shaped main body 15 is covered with a heat insulating material 3l. The baffle plate l8 has a substantially square shape, and extends from the inner end opening of the air supply pipe 17 to the box-shaped main body l5.
It diffuses the air supplied under pressure in all directions.

Said perforated plate 20. - 23.24 uses punching metal. The quartz glass tube heater 22 has a box-shaped body l.
Both ends are clamped by metal fittings 33 attached to the outer surface of 5 via a mounting plate 32. The rectifying material 25 uses a heat insulating material such as asbestos, for example. This straightening material 25 also functions as a filter to remove flux components contained in the hot air used for reflow soldering, and the material or density of this straightening material 25 can be changed by removing the perforated plate 24. This allows the wind speed to be easily adjusted. The workpiece conveyance line 11 is composed of a conveyor in which endless chains are movably incorporated in a pair of guide rails, and a workpiece (surface mount board) W is conveyed between the pair of endless chains as shown in FIG. Load and transport.

As shown in FIGS. 4 and 5, the main body frame 4
The device main body 42 is divided into upper and lower parts on the upper side of the device. 4
3 are integrally attached via a packing 44.

Then, this device main body 42. On the workpiece unloading side of 43,
The hot air generator 12. 13 are built into the upper and lower sides of the workpiece conveyance line 11, and further,
Device body 42. Preheating zone forming members 45 . A hot air duct 47 is formed around the workpiece conveyance line l1 by these (apparatus main body 42, 43, hot air generator +2, H, and preheating zone forming member 45, 46).

As shown in FIG. 4, the upper preheating zone forming member 45 has a protrusion 51 and a recess 52.
The upper side of the gap 53 provided at the tip of the protrusion 5l,
A hot air outlet 54 is provided on the upper side of the recess 52, respectively.
5'5 is provided. There are two hot air suction ports 55. Further, a slope 5G and a recess 57 are formed in the lower preheating zone forming member 46, and a hot air suction pipe 59 having a hot air suction port 58 opened in the direction of the slope 56 is fitted into the recess 57. It is worn.

Then, a hot air suction port 54 and two hot air suction ports 55 are provided.
The openings at both ends of the hot air suction pipe 59 are connected to the main body frame 41.
The air is collected in an intake header 6l installed in the interior, and is communicated from this intake header 61 through a pipe 62 to an intake port 64 of a blower 63. A flux removing device 65 containing a cotton-like activated carbon filter is interposed in a pipe 62 that communicates the intake header 6l with an intake port 64 of the blower 63.

Furthermore, the discharge port 66 of the blower 64 is connected to the discharge head 67.
The hot air generators 12, 13 are distributed and communicated with each air supply port 16 of the hot air generator 12, 13 through the hot air generators 12, 13.

Furthermore, as shown in FIG. 4, the workpiece transport line l! is located on the workpiece unloading side of the hot air duct 47. tube 7 on the underside of
This pipe 71 is provided with a nozzle (small hole) 71 that blows out relatively low-temperature air toward the workpiece loading side.

Next, the operation of this embodiment will be explained.

Inside the hot air duct 47, the hot air generator 12, which is relatively located on the workpiece unloading side, is heated by the blower 63's discharge and intake action.
13 to the hot air suction port 54, ss. ．．
Hot air (headwind for the workpiece W) moves toward sg. Then, the preheating zone forming member 4 is heated by this hot air.
5. The workpiece W carried in between the two hot air generators 12. When the pair of hot air generators 12. The workpiece W is heated by the hot air directly jetted from the workpiece W.

This hot air generator12. At H, the air pressurized and supplied from the blower 63 through the air supply port 16 into the box-shaped body 15 is not rectified much by the first perforated plate 20 and collides with the heater 22 with force. Since turbulence is likely to occur around the heater 22, the heat transfer rate from the heater 22 to the gas is good. The high-temperature airflow heated by this heater 22 has a uniform flow velocity and heat over the entire surface of the hot air outlet 26 when it passes through the cotton-like straightening material 25 filled between the pair of perforated plates 23 and 24. The hot air is rectified so as to have a uniform distribution, and is blown out from the hot air outlet 26 to the workpiece conveyance line l1.

In this way, a pair of hot air generators 12. which face each other are connected to the workpiece (surface-mounted substrate) W transported within the hot air duct 47. The hot air blown from 13 acts efficiently in a compressed state and efficiently heats the workpiece W, and reflow soldering is performed by this high-temperature hot air.

As a result, as shown in FIG. 6, hot air heating can be performed with small variations in workpiece temperature and short heating time.

If necessary, the relatively low-temperature gas ejected from the nozzle 72 can block the hot air blown from the hot air generator l3 on one side of the work W to one side of the workpiece W, for example, a board whose one side has been subjected to reflow soldering. Avoid heating the surface of the board to high temperatures, or the surface of the board with a small heat capacity on one side. The hot air from the hot air generator l3 whose direction is changed to the workpiece loading side by the gas injected from the nozzle 72 is used to preheat the workpiece W.

Note that the nozzle 72 may be provided above the workpiece conveyance line I1.

〔Effect of the invention〕

According to the invention of claim 1, since the cotton-like straightening material having heat resistance and air permeability is provided between the pair of perforated plates on the hot-air outlet side of the hot-air generator, this cotton-like straightening material By completely eliminating variations in heating temperature, it is possible to perform uniform glue flow soldering using only hot air heating. Further, since excellent rectification can be performed using the cotton-like rectifying material, the hot air generator can be configured compactly by placing the heater close to each other. Furthermore, this cotton-like straightening material can remove the flux contained in the hot air, and the speed of the hot air can be easily adjusted by changing the packing density.

According to the invention of claim 2, since a hot air duct is formed around the workpiece conveyance line by a pair of hot air generators arranged above and below the workpiece conveyance line, compressed air is generated inside the hot air duct. The heated hot air enables efficient reflow soldering.

According to the invention of claim 3, since the pair of hot air generators are disposed relatively on the workpiece delivery side of the hot air duct and the hot air suction port is provided on the workpiece delivery side of the hot air duct, the workpiece conveyance direction is provided inside the hot air duct. A high-temperature headwind is created that faces the workpiece, and the workpiece can be preheated by this high-temperature headwind. Therefore, there is no need to provide a preheater, and the device can be constructed compactly.

According to the invention of claim 4, a nozzle is provided on the workpiece unloading side of the hot air duct and on the upper or lower side of the workpiece conveyance line, for spouting relatively low temperature gas toward the workpiece loading side. Accordingly, the relatively low-temperature gas ejected from this nozzle can block the hot air blown onto one side of the workpiece from the hot air generator on one side, thereby protecting parts on one side of the workpiece that do not need to be heated.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a hot air generator used in the air reflow device of the present invention, Fig. 2 is a sectional view taken along the line
4 is a sectional view showing an embodiment of the air reflow device of the present invention, FIG. 5 is a sectional view taken along the line V-V in FIG. 4, and FIG. 6 is an air reflow device according to the present invention. FIG. 7 is a temperature characteristic diagram of a workpiece reflow soldered by an infrared reflow apparatus. FIG. W...Work, l1...Work transfer line, l2, l3
...Hot air generator, 15..Box-shaped body, 16..Air supply port,
22... Heater, 23. 24... Perforated plate, 25... Straightening material, 26... Hot air outlet, 47... Hot air duct, 5
4. 55. 58...hot air outlet, 63...prop, 64...intake port, 66...exhalation port, 72...nozzle. 11th day

Claims (4)

[Claims] (1) In an air reflow device that performs reflow soldering using high temperature of hot air, a hot air generator is opposed to a workpiece conveyance line, and this hot air generator has a box-shaped body and a workpiece conveyance line of this box-shaped body. is an air supply port provided on the opposite side, a hot air outlet provided on the work transfer line side of this box-shaped body, a heater provided inside the box-shaped body, and a hot air outlet provided on the side of the hot air outlet from this heater. 1. An air reflow device comprising: a pair of perforated plates provided in the holder; and a cotton-like rectifier having heat resistance and air permeability filled between the pair of perforated plates. (2) Claim 1 characterized in that a hot air duct is formed around the workpiece conveyance line by disposing a pair of hot air generators and a preheating zone forming member above and below the workpiece conveyance line. Air reflow device as described. (3) A pair of hot air generators are arranged relatively on the workpiece unloading side of the hot air duct, a hot air suction port is provided on the workpiece loading side of the hot air duct, this hot air suction port is communicated with the air intake port of the blower, and the hot air suction port is connected to the air intake port of the blower. 3. The air reflow device according to claim 2, wherein an air discharge port of the hot air generator is connected to an air supply port of the hot air generator. (4) A nozzle for spouting relatively low-temperature gas toward the workpiece transport side is provided on the workpiece transport side of the hot air duct and above or below the workpiece transport line. 3. The air reflow device described in 3.