JP3152059B2 - Reflow equipment - 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 of soldering an electronic component to a substrate by blowing hot air onto the substrate while conveying the substrate on which the electronic component is mounted by a conveyor, or printing or mounting the electronic component on the substrate. The present invention relates to a reflow apparatus for forming solder bumps by melting solder.

[0002]

2. Description of the Related Art In general, a reflow apparatus for soldering electronic components to a substrate is configured to blow hot air onto the substrate while transporting the substrate by a conveyor from an entrance to an exit of a main body box containing a heater and a fan. The solder is heated and melted, and the electronic component is soldered to the substrate (for example, JP-A-2-263570). Such a conveyer-type reflow apparatus has an advantage that it can automatically and mass-sold a substrate while transporting the line, and is currently widely implemented as a main equipment of an electronic component mounting line.

[0003]

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

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

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a main body box having a built-in heater, a conveyor for conveying substrates from an inlet to an outlet of the main body box, and a substrate being conveyed inside the main body box. Detecting means for detecting the number of sheets, a first stopper located upstream of the entrance to prevent the transfer of the substrate to the main body box, and a first stopper located upstream of the first stopper. A second stopper for preventing the transfer of the substrate to the main body box, and when the number of sheets is equal to or less than the set number, releases the state of the first stopper to prevent the transfer of the substrate and conveys the substrate toward the main body box; When the substrate has passed through the first stopper, the first stopper is returned to the state in which the substrate is prevented from being transported again, and the state in which the substrate is prevented from being transported by the second stopper is released. 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 configuration, the number of substrates in the main body box is set to be equal to or less than the set number, and all the substrates can be uniformly reflow-processed.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a reflow device according to one embodiment of the present invention, FIG. 2 is a plan view of a carry-in conveyor provided in the reflow device, and FIGS. 3 and 4 are flowcharts of the operation of the reflow device. In FIG. 1, reference numeral 1 denotes a main body box in which a plurality of heaters 2 and fans 3 are built. Reference numeral 4 denotes a motor for driving the fan 3. An entrance 5 is opened on the left side of the main body box 1, and an exit 6 is opened on the right side. Reference numeral 7 denotes a conveyor provided in the main body box 1, which conveys the substrate 8 from the entrance 5 to the exit 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 denotes a carry-in conveyor provided upstream of the conveyor 7. 1 and 2, the carry-in conveyor 11 is a belt conveyor.
Are provided along the pair of guide rails 12A, 12B. The guide rails 12A and 12B guide the transfer of the substrate 8. Loading conveyor 1 upstream of entrance 5
A first cylinder 13 as a first stopper is provided on 1. As shown in FIG. 1, the first cylinder 1
When the third rod 14 protrudes downward, the transport of the substrate 8 is prevented. When the rod 14 retreats upward, the transport inhibition state of the substrate 8 is released, and the substrate 8 is transported toward the main body box 1. Reference numeral 15 denotes a bracket for mounting the first cylinder 13.

1 and 2, at a position upstream of the first cylinder 13, a second stopper as a second stopper is provided.
Cylinder 16 is provided. The second cylinder 16 is mounted on the side of one of the guide rails 12A in a horizontal posture. When the rod 17 projects, the second substrate 8 whose conveyance is prevented by the first cylinder 13 is removed. The side surface is pressed by the rod 17 and pressed against the other guide rail 12B, and the conveyance is prevented. When the rod 17 is retracted, the substrate 8 is released from the transport inhibition 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 board 8 carried into the main body box 1. The outlet 6 is provided with a second sensor 19. 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. The third sensor 20 detects whether or not the first stopper 13 has stopped the substrate 8. 21 is a control unit,
First sensor 18, second sensor 19, third sensor 2
0, the first cylinder 13, the second cylinder 13,
And the like of the cylinder 16 are controlled.

In FIG. 1, reference numeral 22 denotes a first memory, which stores the maximum number Nmax of substrates 8 that are 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 substrates 8 entering the main body box 1 from the entrance 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 out from the outlet 6
Is stored one by one. A fourth memory 25 stores the minimum interval Tmin. Minimum interval Tmin
Means that the circuit board 8 is attached to the main body box 1 at a shorter time interval.
Is set to prevent the substrates 8 from approaching each other inside the main body box 1, and is set based on the transport speed of the conveyor 7, dimensions of the substrates 8, and the like. You. The control unit 21 controls the first memory 2
2, the first cylinder 13 and the second cylinder 16 are controlled while reading data stored in the second memory 23, the third memory 24, the fourth memory 25, and the like. 2
Reference numeral 6 denotes a timer, which inputs the current time to the control unit 21. An operation unit 27 of the control unit 21 is operated by an operator.

This reflow apparatus has the above-described configuration. Next, the operation will be described with reference to the flowcharts of FIGS. First, at the start of operation, the number N1 of the second memory 23 and the number N2 of the third memory 24 are set.
Has been reset to "0" (step 1). The first cylinder 13 is "closed" and the second cylinder 16 is "closed".
“Open” (step 2).
4 and 17 are in a state in which the transfer of the substrate 8 is prevented by protruding, and “open” is a state in which the rods 14 and 17 are retracted and the transfer of the substrate 8 is permitted.

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 smaller than or equal to the maximum number Nmax (step 6). Further, it is determined whether or not the time T of the timer 26 is equal to or longer than the minimum interval Tmin (step 7). If YES is determined in both Step 6 and Step 7, the substrate 8 may be carried into the main body box 1.

Therefore, the first cylinder 13 is opened and the second cylinder 13 is opened.
Is closed (step 8), and the substrate 8 which has been prevented from being transported by the first cylinder 13 is started to be transported toward the main box 1. In this case, by keeping the second cylinder 16 closed, the two substrates 8 are prevented from being erroneously conveyed to the main box 1 by mistake. Also, as described above, one substrate 8 is provided,
If it is conveyed to main body box 1, timer 2
6 is reset (step 9). At the start of operation, the board 8 does not exist inside the main body box 1, so that N1
= 0, N2 = 0 and T ≧ Tmin,
The substrate 8 is transported 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 under the first sensor 18 and has been sent into the main body box 1). If confirmed), the first cylinder 13 is "closed" and the second cylinder 16
Is opened, the substrate 8, which had been blocked by the second cylinder 16, is transferred to the first cylinder 13, stopped by the rod 14, and stands by (step 11). ). Next, the number N1 of substrates 8 in the main body box 1 is counted up by one (step 12).
Next, in step 13, if the second sensor 19 switches from ON to OFF (that is, if it is confirmed that the substrate 8 has been carried out of the main body box 1), the number N2 is counted up by one. (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, and 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. If NO in step 6, the process proceeds to step 10 and the operations in and after step 10 are repeated until N ≦ Nmax.
The number of substrates 8 larger than the maximum number Nmax is prevented from being fed into the main body box 1. NO in step 7
In the case of, the process also proceeds to step 10 and waits until T ≧ Tmin, whereby the distance D (FIG. 1) between the substrates 8 becomes abnormally small, and the density of the substrates 8 in the main body box 1 becomes extremely high. To prevent it from becoming too high.

[0017]

As described above, according to the present invention, it is possible to manage the number of substrates in the main body box and the distance between the substrates, and accordingly, the number of substrates and the distance in the main body box can be properly adjusted. While maintaining, all the substrates are heated so as to have a desired temperature profile, so that uniform and high quality soldering can be realized.

[Brief description of 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 device according to one embodiment of the present invention.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body box 2 Heater 3 Fan 5 Inlet 6 Outlet 7 Conveyor 8 Substrate 13 1st cylinder (1st stopper) 16 2nd cylinder (2nd stopper) 18 1st sensor 19 2nd sensor 21 Control part

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H05K 3/34 B23K 1/008 B65G 43/00 B65G 47/28 B65G 47/88

Claims (1)

(57) [Claims] 1. A main body box containing a heater, a conveyor for conveying substrates from an inlet to an outlet of the main body box, detecting means for detecting the number of substrates being conveyed inside the main body box, and A first stopper at a position upstream of the first stopper for preventing the transfer of the substrate to the main body box, and a first stopper at a position upstream of the first stopper for preventing the transfer of the substrate to the first stopper. And when the number of sheets is equal to or less than the set number, the state in which the first stopper is stopped from transporting the substrate is released, and the substrate is transported toward the main body box. When the first stopper has passed, the first stopper is again returned to the substrate transfer inhibited state, and the substrate transfer inhibited state by the second stopper is released, and the substrate is removed from the first stopper. Reflow apparatus characterized by comprising a control unit for controlling to convey toward the stopper.