JP3146802B2 - Method of shutting down reflow device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for shutting down a reflow device in which the temperature of a furnace inside becomes high due to operation, in a short time.

[0002]

2. Description of the Related Art Reflow devices are widely used for soldering electronic components surface-mounted on a substrate to circuit patterns on the substrate. The reflow device has a furnace body divided into a preheating zone, a soaking zone, a reflow zone, and the like by a partition wall, and the substrate conveyed by the conveyor in the reflow device is heated according to a predetermined temperature profile in each zone. . Here, during the operation of the reflow device, the temperature inside the furnace has reached a maximum of about 400 ° C.

[0003] However, when a trouble occurs in the furnace, such as when a substrate is dropped from a conveyor in the furnace, and an operator needs to reach into the furnace, the reflow device is lowered and the furnace is lowered. Temperature must be reduced to a safe temperature.

[0004]

Conventionally, when the reflow device is lowered in this way, an operator simply turns off the heater in the reflow device and leaves the reflow device until the temperature inside the furnace naturally drops. have been waiting.

However, in this case, it takes a long time of about one full day until the temperature inside the furnace is lowered to a safe temperature, and during this time, the operation cannot be resumed, and the operation rate of the reflow device decreases. There was a point.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for lowering a reflow device, which can bring the reflow device down in as short a time as possible.

[0007]

The present invention comprises a lower furnace body,
From the upper furnace body connected to the lower furnace body so that the lower part can be opened and closed
In a reflow device with a furnace body consisting of
The reflow device to lower the temperature to a safe temperature
Method, to turn off the heater in the furnace body in a hot state
External air is forcibly sent into the furnace by driving the step and fan
Step of lowering the temperature inside the furnace by blowing
That the temperature inside the furnace has dropped below the open temperature
When the sensor detects, open the upper furnace body and open the furnace body,
Reduce the temperature inside the furnace to a temperature at which the cooling can be completed.
And

[0008]

According to the above construction, the outside air much lower than the temperature in the furnace mixes with the gas in the furnace, and the temperature in the furnace can be rapidly lowered.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a reflow apparatus according to an embodiment of the present invention. In the furnace body B, 1 is a lower furnace body fixed to a base G and an upper part is opened, and 1a is a lower furnace body 1. The protruding piece 2 protruding from the rear part is the protruding piece 2 protruding from the rear part.
The upper furnace body is pivotally supported by the protruding piece 1a and the shaft 3 so that the lower furnace part can be freely opened and closed as shown by the chain line in FIG. An elongated hole 2b is formed at the rear of the protruding piece 2a, and the upper end of the rod 4a of the upward cylinder 4 fixed to the base G is connected to the elongated hole 2b.
Accordingly, when the cylinder 4 is driven to project the rod 4a, the upper part of the lower furnace body 1 can be closed by the upper furnace body 2 as shown by the solid line in FIG. Conversely, rod 4a
1, the upper furnace body 2 is rotated upward about the shaft 3 as shown by the chain line in FIG. 1, the upper furnace body 2 and the lower furnace body 2 are opened, and the furnace body B is moved. Can be opened.

FIG. 2 is a vertical sectional view of the reflow apparatus.
Reference numeral 5 denotes a conveyor provided across the entire furnace body B and transporting a substrate 7 on which electronic components 6 are mounted in the direction of arrow N.
In the furnace body B, opposing partition walls 2c, 1c, and partition walls 2d, 1d are provided in the upper furnace body 2 and the lower furnace body 1, respectively, and inside the furnace body B, these partition walls 2c, 1c are provided. , 2
d, 1d, along the arrow N direction, the preheating zone A
1, divided into a soaking zone A2 and a reflow zone A3. H1 and H2 are heaters disposed above and below the conveyor 5 in the preheating zone A1, similarly, H3, H4 and H5.
H6 is a heater disposed above and below the conveyor 5 in the soaking zone A2 and the reflow zone A3. The heaters H1, H3, H3 are provided in the respective zones A1, A2, A3.
Fans 8, 9, 10 for diffusing the heat of H5 and motors M1, M for rotating these fans 8, 9, 10
2 and M3 are provided, and 14 is a temperature sensor for detecting the temperature inside the furnace body B. 11 furnace N ₂ gas supply unit for supplying a N ₂ gas into B, 12 is the air supply, such as a blower sending the outside air into the furnace B, these N ₂ gas supply unit 11, the air supply unit 12 The discharge side of
Preheating zone A1, soaking zone A2, reflow zone A3
In communication with each other. V1 is the preheating zone A
A valve for permitting or disallowing the discharge of N ₂ gas or air to 1; similarly, V2 and V3 are valves for controlling the discharge to the soaking zone A2 and the reflow zone A3; A valve V5 is a valve for permitting or disallowing the discharge of the N ₂ gas supply unit 11. Incidentally, these valves V1 to V5 are composed of solenoid valves and the like.

FIG. 3 is a block diagram of the reflow apparatus. Reference numeral 15 denotes a ROM for storing a control program including the processing of the flowchart of FIG. 4, and an R provided with a work area.
The control unit includes an AM, an interface that controls input / output, and a CPU that controls these.

FIG. 4 is a flowchart showing the flow of processing in the control unit 15, and a method for shutting down the reflow apparatus of the present embodiment will be described with reference to this flowchart. First, when the process of shutting down is started from a state where the inside of the furnace body B is at a high temperature, the heaters H1 to H1 of the zones A1, A2, A3 are firstly set.
The energization to H6 is cut off (step 1). The control unit 15 drives the motors M1 to M3 to drive the fans 8 to 10
Is rotated (step 2). Then, the air supply unit 12 is driven so that the outside air can be forcibly blown (step 3), and the valves V1, V2, V3, and V4 are fully opened (step 4). Forcibly blow much lower outside air. As a result, the temperature inside the furnace body B starts to rapidly decrease. Then, the control unit 15 monitors the output of the temperature sensor 14 and holds this state until the temperature becomes equal to or lower than the open temperature (about 150 ° C.) (step 5). Here, outside air is forcibly blown to each of the zones A1, A2, and A3. At this time, since the fans 8 to 10 are rotating, the high-temperature gas in the furnace B and the outside air are sufficiently stirred.

When the temperature sensor 14 detects that the temperature is equal to or lower than the above-mentioned open temperature, the control unit 15 drives the cylinder 4 to project the rod 4a, and as shown by the chain line in FIG. Open and open the furnace body B (step 6). Accordingly, not only the pipe 13 but also the outside air around the reflow device enters the furnace body B from between the upper furnace body 2 and the lower furnace body 1. Of course, since the volume of the outside air around the reflow device is much larger than the volume of the gas in the furnace B, the inside of the furnace B is cooled more rapidly. Then, the control unit 15 monitors the output of the temperature sensor 14 again, confirms that the temperature inside the furnace body B has decreased to a temperature (about 60 ° C.) at which the shutdown can be completed (Step 7), 12 are stopped (step 8), the valves V1 to V4 are closed (step 9), and the motors M1 to M3 are stopped (step 1).
0), shutdown is completed.

[0014]

As described above, according to the present invention, a high
The temperature inside the furnace can be rapidly lowered by forcibly mixing the outside air at a much lower temperature than the inside of the furnace with the gas in the furnace in the warm state, and a quick shutdown process can be performed. For this reason,
The shutdown processing can prevent the operation rate of the reflow device from being significantly reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a reflow device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a reflow device according to an embodiment of the present invention.

FIG. 3 is a block diagram of a reflow device according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a method for shutting down a reflow device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower furnace body 2 Upper furnace body 4 Cylinder 12 Air supply part 14 Temperature sensor B Furnace body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 3/34 B23K 1/008 B23K 31/02

Claims (1)

(57) [Claims] 1. A lower furnace body and a lower openable / closable lower body.
Reflow device with a furnace body consisting of an upper furnace body connected to
To reduce the temperature inside the furnace to a safe temperature
The method for shutting down a reflow device according to claim 1, wherein the furnace body is in a high temperature state.
To turn off the heater inside and to drive the fan
The temperature inside the furnace is increased by forcibly blowing outside air into the furnace.
The temperature in the furnace is below the opening temperature.
When the temperature sensor detects that the temperature has dropped below,
Open the furnace body to complete the temperature reduction in the furnace body
Lowering the temperature to an acceptable temperature .