JPH0751273B2 - Substrate heating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating device for soldering electronic parts by heating and melting cream solder applied on a circuit board.

Conventional technology Printed circuit boards (hereinafter referred to as “P
It is abbreviated as “board”. ) In the high-density mounting technology of electronic parts on top, the soldering method of the element using the reflow furnace is being adopted. Here, the main heating method will be described by taking the soldering method using the reflow furnace as an example. The reflow method is different from the conventional flow method in which the P plate on which the element is placed is dipped in the molten solder bath, and the element is placed after the creamy solder consisting of fine solder particles and paste is applied to the P plate at a predetermined position. It is heated and melted by infrared rays and soldered.

An example of the conventional substrate heating apparatus described above will be described below with reference to the drawings.

FIG. 3 shows a schematic structure of a conventional substrate heating apparatus. Third
In the figure, 1 is a conveyor, 2 is a P plate, 3 is a heating element,
Reference numeral 4 is a heating chamber, and 5 is a cooling fan. The heating chamber 4 has a tunnel shape and a hollow inside in the horizontal direction. The heating element 3 is installed on the upper part of the heating chamber 4 so that the conveyor 1 for transporting the P plate 2 travels in the heating chamber 4. It has become.

The operation of the substrate heating device configured as described above will be described below. On the conveyor 1 that moves at a constant speed v,
The P plate 2 on which the element is placed is heated by the heating element 3 which continues to generate a certain amount of heat. The first half A in front of the furnace is the preheating section,
Normally, warm P board 2 around 150 ° C. Next, about 250 ° C in part B
Then, it is soldered, then cooled by the cooling fan 5 and taken out.

However, in the above-described configuration, there is a backflow from the atmosphere outside the heating chamber 4 into the heating chamber 4, or a backflow of the atmospheric temperature atmosphere into the heating chamber 4 due to the cooling fan 5 or the like. Then, the temperature in the heating chamber 4 becomes non-uniform, and there is a problem that a soldering failure in which soldering cannot be performed partially occurs.
Actually, when the temperature of the P plate 2 to which the thermocouple was fixed with the high temperature solder was measured, the uniformity was ± 4%. Moreover, it was very difficult to maintain the preheating part A and the soldering heating part B at predetermined temperatures by adjusting the heating element 3.

In view of the above problems, the present invention improves temperature uniformity in the heating chamber and provides means for keeping the preheating portion and the soldering portion at predetermined temperatures, thereby improving soldering failure and stabilizing element quality. The present invention provides a substrate heating device capable of performing the above.

Means for Solving the Problems In order to solve the above problems, the present invention relates to a substrate heating apparatus having a tunnel-shaped heating chamber having a heating unit, and a unit capable of transporting a substrate in the heating chamber. Two
There are hot air supply ports for supplying hot air of different temperatures from different locations, and a pair of partition plates facing each other is provided between the two hot air supply ports so as not to impede the conveyed substrate, and between the partition plates. It has an exhaust port.

Action The present invention provides the heating chambers with a pair of partition plates facing each other within a range that does not block the transfer substrate, and supplies hot air of different predetermined temperatures to the heating chambers with the partition plates as a boundary. The ambient temperature can be maintained at different predetermined temperatures. Further, by providing an exhaust port between the partition plates with the partition plate as a boundary, it is possible to reduce the interaction due to the predetermined ambient temperature of each heating chamber, and it is possible to further maintain each heating chamber at the predetermined temperature. .

Embodiment A substrate heating apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a substrate heating apparatus according to the first embodiment of the present invention.

In FIG. 1, 6 is a preheating chamber, 7 is a soldering heat chamber,
8 is a partition plate, 9 is a hot air supply port, 10 is a heating element, 11 is a P plate,
12 is a conveyor and 13 is a cooling fan.

The operation of the substrate heating device configured as described above will be described below.

First, the chip-mounted P board 11 to which cream solder is applied is placed on the conveyor 12 and sent to the preheating chamber 6 to generate the heating element 10.
It is heated to around 150 ℃. Next, the solder addition heat chamber 7
And is supplied from the heating element 10 and the hot air supply port 9 25
The P plate is heated to about 250 ° C. by hot air around 0 ° C., and finally cooled by the cooling fan 13 and taken out.

As described above, according to the present embodiment, by supplying hot air having a constant temperature to the heating chamber, the air flow flows from inside the solder addition heat chamber 7 to outside the solder addition heat chamber 7, and the solder addition heat chamber 7 Since the outside air does not flow into the inside of the solder 7, the temperature in the solder addition heat chamber can be made uniform. Further, by supplying hot air at a predetermined temperature, the solder addition heat chamber 7 is brought to a predetermined temperature.
Can be maintained, and the defective solder rate due to uneven temperature can be reduced.

Actually, when the thermocouple was fixed to the P plate 11 with the high temperature solder and the temperature was measured, the uniformity was improved to ± 1.5%.

Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows a substrate heating apparatus according to the second embodiment of the present invention.

In FIG. 2, 14 is a preheating chamber, 15 is a soldering heat chamber, 1
6 is a partition plate, 17 is a first hot air supply port, 18 is a second hot air supply port, 19 is a heating element, 20 is a P plate, 21 is a conveyor, 22 is a cooling fan, 23 is an upper exhaust port, and 24 is a lower part. It is an exhaust port.

The operation of the substrate heating device configured as described above will be described below.

First, the chip mounting P board 20 coated with cream solder is placed on the conveyor 21 and sent to the preheating chamber 14. About 150 ° C 1m / that is supplied from the heating element 19 and the second hot air supply port 18
The hot air of s forms a soaking zone of an atmosphere of about 150 ° C. in the preheating chamber 14, and the P plate 20 is also uniformly heated to about 150 ° C. in the preheating chamber 14. Next, the P plate 20 is transported to the solder addition heat chamber 15 and is heated in the heat equalizing zone formed by the heating element 19 and the hot air of about 230 ° C. and 1 m / s supplied from the first hot air supply port 17 It is heated to 250 ° C. Then, it is cooled by the cooling fan 22 and taken out. Further, since hot air of different temperature is supplied to each of the preheating chamber 14 and the solder addition heat chamber 15, in order to reduce the influence of each other's atmosphere, the upper exhaust port 23 (exhaust speed 0.5 m / s and Lower exhaust port 24
Exhaust is performed at (exhaust speed 0.5m / s).

As described above, according to the present embodiment, the partition plate 16 is provided between the preheating chamber 14 and the solder addition heat chamber 15, and the preheating chamber 14 and the solder addition heat chamber 15 have hot air of different predetermined temperatures. By supplying the above, it is possible to maintain the ambient temperature of each heating chamber at different predetermined temperatures, and it is possible to expand the soaking region by the effect of hot air blowing. Further, by providing the upper exhaust port 23 and the lower exhaust port 24 in the vicinity of the partition plate 16 with the partition plate 16 as a boundary, it is possible to reduce the interaction between the preheating heating chamber 14 and the solder addition heat chamber 15 due to a predetermined ambient temperature. Therefore, the heating chamber can be maintained at a predetermined temperature.

Next, a third embodiment of the present invention will be described with reference to the drawings.

The substrate heating apparatus in the third embodiment has exactly the same structure as that of FIG. 2 of the second embodiment, except that the upper exhaust port 23
Has an exhaust speed of 0.2 m / s and the lower exhaust port 24 has an exhaust speed of 0.8 m / s
Is to be.

The operation of the substrate heating device in this case will be described below.

The operation is the same as that of the second embodiment, except that the first hot air supply port 17 (temperature 230 ° C., inflow speed 1 m / s) and the second hot air supply port 18 (temperature 150 ° C., inflow speed 1 m / s) In order not to disturb the flow of hot air supplied from (s), the exhaust speed of the upper exhaust port 22 is set to 0.2 m / s and the exhaust speed of the lower exhaust port 24 is set to 0.8 m / s.

As described above, in the third embodiment, a partition plate is provided between the preheating chamber 14 and the solder addition heating chamber 15, and hot air having different predetermined temperatures is supplied to the preheating chamber 14 and the solder heating chamber 15, respectively. As a result, the ambient temperature of each heating chamber can be maintained at different predetermined temperatures, and the uniform heating area can be expanded by the effect of hot air blowing. Also, with the partition plate 16 as a boundary, an upper exhaust port 23 and a lower exhaust port 24 are provided in the vicinity of the partition plate 16, and the exhaust speed of the lower exhaust port 24 is made higher than the exhaust speed of the upper exhaust port 23 to supply the hot air supplied. It is possible to reduce the interaction between the preheating chamber 14 and the solder addition heat chamber 15 due to the predetermined ambient temperature without disturbing the flow of the heat treatment, and to further bring the preheating chamber 14 and the solder addition heat chamber 15 to the predetermined temperatures. Can be kept.

Although the upper exhaust port 23 and the lower exhaust port 24 are used in the second and third embodiments of the present invention, only the lower exhaust port 24 may be used.

Further, although the heating elements 10 and 19 of the present invention are provided only in the upper part, they may be heated from both upper and lower sides.

In the first, second and third embodiments of the present invention, P
Although the cooling fans 13 and 22 are attached for cooling the plate, they may be omitted.

Also, the reflow soldering of the substrate has been described as an example, but it goes without saying that this content can be applied to any general substrate heating.

EFFECTS OF THE INVENTION According to the present invention, the heating chamber is provided with a pair of partition plates that oppose each other within a range that does not block the transfer substrate, and the partition plates serve as boundaries to supply hot air of different predetermined temperatures to each heating chamber. The ambient temperature of each heating chamber can be maintained at different predetermined temperatures. Further, by providing an exhaust port between the partition plates with the partition plate as a boundary, it is possible to reduce the interaction due to the predetermined ambient temperature of each heating chamber, and it is possible to further maintain each heating chamber at the predetermined temperature. .

[Brief description of drawings]

FIG. 1 is a sectional view of a substrate heating apparatus in a first embodiment of the present invention, FIG. 2 is a sectional view of a substrate heating apparatus in a second embodiment of the present invention, and FIG. 3 is a conventional substrate heating apparatus. FIG. 6,14 ... Preheating chamber, 7,15 ... Solder heating chamber, 8,16 ... Partition plate, 9 ... Hot air supply port, 17 ... First hot air supply port, 18 ...
… Second hot air supply port, 10,19 …… Heating element, 11,20 …… P plate,
12,21 …… Conveyor, 23 …… Upper exhaust port, 24 …… Lower exhaust port.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takahata Ichiyanagi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Susumu Saito, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Takao Naito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A 63-278668 (JP, A) JP-A 51-101863 (JP, A) 61-4870 (JP, U)

Claims (3)

[Claims] 1. A tunnel-shaped heating chamber having heating means,
A substrate heating apparatus having means for transporting a substrate in the heating chamber, having hot air supply ports for supplying hot air of different temperatures from two locations, and transporting between the two hot air supply ports A substrate heating device having a pair of partition plates facing each other within a range that does not block the substrate to be formed, and having an exhaust port between the partition plates. 2. A substrate heating apparatus according to claim 1, further comprising a lower exhaust port directly below a pair of opposing partition plates. 3. The substrate heating apparatus according to claim 1, wherein the exhaust speed of the exhaust port provided between the partition plates is smaller than the exhaust speed of the lower exhaust port.