JPH07297537A - Reflow equipment - Google Patents

Abstract

PURPOSE:To provide a reflow equipment capable of performing a uniform reflow processing by controlling the number of sheets and the spacing of boards carried by a conveyer in its main body box. CONSTITUTION:In a reflow equipment, first and second sensors 18, 19 for sensing boards 8 in course of their carriages through its main body box 1 having heaters 2 and fans 3 are provided. Also, in the equipment, first and second cylinders 13, 16 for blocking the carriages of the boards 8 in the upstream of the main body box 1 are provided. When the number of the sheets of the boards 8 is not larger than a preset value, the block state of the carriage of the board 8 which is brought by the first cylinder 13 is released, and the board 8 is carried to the main body box 1. Thereby, the board 8 is passed the first cylinder 13, and thereafter, the first cylinder 13 is returned again to the block state of the carriage of the board 8. Also, in the equipment, a control part 21 is provided. The control part 21 so controls the second cylinder 16 that the board 8 is carried to the first cylinder 13 while the block state of the carriage of the board 8 which is brought by the second cylinder 16 is released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to soldering an electronic component to a substrate by blowing hot air onto the substrate while the substrate on which the electronic component is mounted is conveyed by a conveyor, or printed or mounted on the substrate. The present invention relates to a reflow device for melting solder to form solder bumps.

[0002]

2. Description of the Related Art In general, a reflow device for soldering electronic components to a board is designed to blow hot air onto the board while carrying the board from a entrance of a main body box having a heater and a fan to an exit thereof by a conveyor. The solder is heated and melted, and the electronic component is soldered to the substrate (for example, Japanese Patent Laid-Open No. 2-263570). Such a conveyor-type reflow apparatus has an advantage of being able to automatically and in large quantities solder a substrate while it is being conveyed through the line, and is currently widely used as a main facility for electronic component mounting lines.

[0003]

There are other facilities such as an electronic component mounting device for mounting electronic components on a substrate on the upstream side of the reflow device, and the reflow device has an uneven time interval from these other facilities. The board is sent randomly.
Therefore, the number of substrates conveyed by the conveyor in the main body box of the reflow device is not constant, and the distance between the substrates is not constant. Since the number of substrates in the main body box and the transfer density are not constant in this way, the amount of heat in the main body box taken by the substrates varies, and the flow of hot air blown to the substrates also changes. Therefore, the conventional reflow apparatus has a problem that the temperature profile of the substrate varies and the molten state of the solder also varies, and uniform soldering cannot be performed on all the substrates.

Therefore, an object of the present invention is to provide a reflow apparatus capable of uniformly soldering all substrates by controlling the number of substrates conveyed by a conveyor in the main body box and the distance between the substrates. And

[0005]

To this end, the present invention is directed to a main body box having a built-in heater, a conveyer for conveying a substrate from an inlet to an outlet of the main body box, and a substrate being conveyed inside the main body box. Means for detecting the number of sheets of paper, a first stopper located upstream of the entrance to prevent the substrate from being transferred to the main body box, and a first stopper located upstream of the first stopper. A second stopper that prevents the transfer of substrates to the substrate, and when the number of substrates is less than or equal to the set number, the transfer prevention state of the substrates by the first stopper is released and the substrate is transferred toward the main body box. When the first substrate has passed through the first stopper, the first stopper is returned to the substrate transport blocking state again, and the substrate transport blocking state by the second stopper is released to release the substrate. It is obtained by constituting the reflow apparatus and a control unit for controlling to convey toward the first stopper.

[0006]

According to the above construction, the number of substrates in the main body box can be reduced to the set number or less, and all the substrates can be uniformly reflowed.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view of a reflow apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a carry-in conveyor provided in the reflow apparatus, and FIGS. 3 and 4 are flowcharts of the operation of the reflow apparatus. In FIG. 1, reference numeral 1 is a main body box in which a plurality of heaters 2 and fans 3 are incorporated. 4 is a motor for driving the fan 3. An inlet 5 is opened on the left side of the body box 1, and an outlet 6 is opened on the right side. Reference numeral 7 is a conveyor arranged in the main body box 1 and conveys the substrate 8 from the inlet 5 to the outlet 6. Reference numeral 9 denotes an electronic component mounted on the substrate 8 by an electronic component mounting device provided upstream of the reflow device.

Reference numeral 11 is a carry-in conveyor provided upstream of the conveyor 7. 1 and 2, the carry-in conveyor 11 is a belt conveyor, and the carry-in conveyor 11
A pair of guide rails 12A and 12B are provided so as to follow. The guide rails 12A and 12B guide the transfer of the substrate 8. Carry-in conveyor 1 upstream of the entrance 5
A first cylinder 13 serving as a first stopper is provided on the unit 1. As shown in FIG. 1, the first cylinder 1
When the rod 14 of No. 3 protrudes downward, the conveyance of the substrate 8 is blocked, and when the rod 14 retreats upward, the conveyance-blocked state of the substrate 8 is released, and the substrate 8 is conveyed toward the main body box 1. Reference numeral 15 is a bracket to which the first cylinder 13 is attached.

In FIGS. 1 and 2, a second stopper serving as a second stopper is provided at a position upstream of the first cylinder 13.
Cylinder 16 is provided. The second cylinder 16 is attached to the side portion of the one guide rail 12A in a horizontal posture, and when the rod 17 of the second cylinder 16 projects, the second substrate 8 whose conveyance is blocked by the first cylinder 13 The side surface of the guide rail 12B is pushed by the rod 17 and is pressed against the other guide rail 12B, and the conveyance is blocked. Further, when the rod 17 is retracted, the substrate 8 is released from the transport-inhibited state and is transported toward the first cylinder 13.

In FIG. 1, a first sensor 18 is provided at the entrance 5 of the main body box 1. The first sensor 18 detects the substrate 8 carried into the main body box 1. A second sensor 19 is provided at the outlet 6. The second sensor 19 detects the substrate 8 carried out from the outlet 6. First cylinder 13 and second cylinder 1
A third sensor 20 is provided between 6 and 6. The third sensor 20 detects whether or not the first stopper 13 stops the substrate 8. 21 is a control unit,
First sensor 18, second sensor 19, third sensor 2
The first cylinder 13, the second cylinder
It controls the cylinder 16 and the like.

In FIG. 1, reference numeral 22 denotes a first memory, which stores the maximum number Nmax of substrates 8 allowed to exist in the main body box 1. Reference numeral 23 denotes a second memory, which is the number N of substrates 8 detected by the first sensor 18.
1, that is, the number N1 of the substrates 8 that have entered the main body box 1 from the inlet 5 is stored one by one. Reference numeral 25 denotes a third memory, which is the number N of substrates 8 detected by the second sensor 19.
2, that is, the number N2 of substrates 8 sent from the exit 6.
Memorize every one. A fourth memory 25 stores the minimum interval Tmin. Minimum interval Tmin
Means that the substrate 8 is the main body box 1 at a shorter time interval.
When it is sent to the inside of the main body box 1, it is a time set in order to prevent the boards 8 from coming too close to each other inside the main body box 1, and is set based on the conveyance speed of the conveyor 7 and the size of the board 8. It The control unit 21 uses the first memory 2
2, while controlling the first cylinder 13, the second cylinder 16, and the like while reading the data stored in the second memory 23, the third memory 24, the fourth memory 25, and the like. Two
Reference numeral 6 is a timer, which inputs the current time into the control unit 21. Reference numeral 27 denotes an operation unit of the control unit 21, which is operated by the operator.

This reflow apparatus has the above-mentioned structure, and its operation will be described with reference to the flow charts of FIGS. 3 and 4. First, at the start of operation, the number N1 of the second memory 23 and the number N2 of the third memory 24 are
Has been reset to "0" (step 1). The first cylinder 13 is "closed" and the second cylinder 16 is "closed".
"Open" (step 2). "Closed" means rod 1
4, 17 is a state in which the substrate 8 is prevented from being conveyed, and "open" is a state in which the rods 14 and 17 are retracted to allow the substrate 8 to be conveyed.

Now, in step 3, the timer 26 is started. If the third sensor 20 is "ON" and the board 8 is detected (step 4), the number of boards 8 in the main body box 1 is calculated as N = N1-N2 (step 5), and the number N is calculated. Is determined to be less than or equal to the maximum number Nmax (step 6). Further, it is determined whether the time T of the timer 26 is equal to or longer than the minimum interval Tmin (step 7). If both steps 6 and 7 are YES, the substrate 8 can be carried into the main body box 1 without any problem.

Thereupon, the first cylinder 13 is "open" and the second
The cylinder 16 is closed (step 8), and the substrate 8 which has been blocked by the first cylinder 13 until then is started to be transferred to the main body box 1. At this time, the second cylinder 16 is "closed" so that the two substrates 8 are not mistakenly continuously transferred to the main body box 1. Also, in this way, one substrate 8
If it is transported to the main box 1, the timer 2
6 is reset (step 9). At the start of operation, the substrate 8 does not exist inside the main body box 1, so N1
= 0, N2 = 0, and T ≧ Tmin,
The substrate 8 is transferred into the main body box 1.

Next, in step 10, if the first sensor 18 is switched from ON to OFF (that is, the substrate 8 has passed below the first sensor 18 and has been fed into the main body box 1). If confirmed), the first cylinder 13 is "closed" and the second cylinder 16
Becomes "open", the substrate 8 which has been blocked by the second cylinder 16 until then is transported to the first cylinder 13, the transport is blocked by the rod 14, and the substrate stands by (step 11). ). Next, the number N1 of the substrates 8 in the main body box 1 is counted up by 1 (step 12).
Next, in step 13, if the second sensor 19 is switched from ON to OFF (that is, if it is confirmed that the substrate 8 has been carried out from the main body box 1), the number N2 is counted up by one. Yes (Step 1
4). Then, the process returns from step 14 to step 4, and the above-described operation is repeated. In Steps 4, 6 and 7, N
In the case of O, the process proceeds to step 10, if NO in step 10, the process proceeds to step 13, and if NO in step 13, the process proceeds to step 4, and the above operation is repeated.

If NO in step 4, the process proceeds to step 10. On the other hand, if NO in step 6, the process proceeds to step 10 and the operations in step 10 and subsequent steps are repeated until N ≦ Nmax,
The maximum number Nmax of substrates 8 should not be fed into the main body box 1. Also, in step 7, NO
Also in the case of, the process proceeds to step 10 and waits until T ≧ Tmin, whereby the distance D between the substrates 8 (FIG. 1) becomes abnormally small, and the density of the substrates 8 in the main body box 1 becomes extremely small. Prevent it from getting too high.

[0017]

As described above, according to the present invention, it is possible to control the number of boards in the main body box and the distance between the boards, and thus the number of boards and the distance in the main body box can be properly controlled. While maintaining this, all the substrates can be heated to have a desired temperature profile, and uniform and high quality soldering can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a reflow apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a carry-in conveyor provided in the reflow apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart of the operation of the reflow device according to the embodiment of the present invention.

FIG. 4 is a flowchart of the operation of the reflow device according to the embodiment of the present invention.

[Explanation of symbols]

 1 Body Box 2 Heater 3 Fan 5 Inlet 6 Outlet 7 Conveyor 8 Substrate 13 First Cylinder (First Stopper) 16 Second Cylinder (Second Stopper) 18 First Sensor 19 Second Sensor 21 Control Section

Claims (2)

[Claims] 1. A main body box having a built-in heater, a conveyer for conveying a substrate from an inlet to an outlet of the main body box, a detecting means for detecting the number of substrates being conveyed inside the main body box, and the inlet. A first stopper located upstream of the first stopper to prevent the transfer of the substrate to the main body box; and a first stopper located upstream of the first stopper to prevent the transfer of the substrate to the first stopper. 2 stoppers and when the number of sheets is less than or equal to the set number, the state in which the substrate is prevented from being conveyed by the first stopper is released and the substrate is conveyed toward the main body box. If the first substrate is passed through the first stopper, the first stopper is returned to the substrate transport blocking state again, and the substrate transport blocking state by the second stopper is released to move the substrate to the first block. Reflow apparatus characterized by comprising a control unit for controlling to convey toward the stopper. 2. A main body box having a built-in heater, a conveyer for conveying a substrate from an inlet of the main body box to an outlet, and a conveyer for preventing the conveyance of the substrate to the main body box at a position upstream of the inlet. 1 stopper and this 1st
A second stopper located upstream of the first stopper for preventing the transfer of the substrate to the first stopper;
And a control unit for controlling the transfer of the substrate to the main body box at a predetermined interval by releasing the transfer blocking state of the substrate by the second stopper at regular intervals. Reflow equipment.