JPH08236920A - Solder reflowing device for printed board - Google Patents

Abstract

PURPOSE: To provide a solder reflowing device for printed board which is reduced in size so that the occupying space of the device can be reduced by providing heaters above and below a printed board fixing section in a housing in such a state that the positions of the heaters can be adjusted in the vertical direction. CONSTITUTION: After a printed board P is carried in a housing 1 through a carrying-in port 5 by means of a carrying-in means 7, such as the conveyor, etc., and positioned to a fixing position 2 by means of a conveyor 2a, the board P is heated with upper and lower heaters 3 and 4. The distances between the heaters 3 and 4 and the board P are adjusted by moving the heaters 3 in the upward and downward by moving the holders 9 and 10 of the heaters 3 and 4 upward and downward along guide shafts 11 by rotating threaded shafts 12 and 13 by means of motors 14 and 15. The board P is heated until solder melts in accordance with a temperature file. After heating, the heaters 3 and 4 are separated from the board P and the board P is cooled.

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] A solder paste is applied to a predetermined position of a printed circuit, and a printed board on which a chip or the like is mounted is placed in a solder reflow device and heat-treated.
The present invention relates to a solder reflow device for a printed circuit board, which is adapted to solder a chip or the like.

[0002]

2. Description of the Related Art In the process of mounting (soldering) chips and other electronic parts (hereinafter simply referred to as chips) on a printed circuit of a printed circuit board, a predetermined solder paste is applied to a predetermined position of the printed circuit board. Then, a chip or the like is mounted on the position with a chip mounting device or the like (hereinafter, the printed circuit board that has been processed up to this point is simply referred to as a printed circuit board), and the printed circuit board is heat-treated with a solder reflow device. Soldering (mounting and mounting a chip etc.) is generally performed.

The solder reflow device for a printed circuit board currently used is to heat a printed circuit board continuously conveyed on a conveyor in the device with far infrared heaters having three or more surfaces and hot air, and has a temperature profile (see FIG. 4). ), Heating is gradually performed (preheating: preheating), and then heating is performed up to the solder melting temperature for soldering.

As described above, the reason for heating in the order of the temperature profile is that, for example, when the solder melting point is rapidly heated without preheating, problems such as chip upright phenomenon (Manhattan phenomenon) and solder bridge occur. This is because the soldering yield frequently decreases and the soldering yield extremely decreases.

[0005]

However, in the conventional solder reflow apparatus a, as shown in FIG. 3, the heaters 103a, 103b, 103c, 103d are used to convey the printed circuit board P by the conveyor 102 in the housing 101. It is configured to perform heating and preheating to solder fusion processing, and the so-called temperature profile heating time is set to the conveyor 1
Since it is configured to replace the traveling speed and the traveling distance of 02, the device is naturally large (illustrated example, length 1000 mm, width 3500-40
00mm, height 1250mm), requiring a large installation space,
The problem is that the price is also high,

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention has the following objects in order to solve the above conventional problems.

To downsize the solder reflow device, reduce the installation space, and reduce the device cost.

In order to downsize the apparatus, an extremely horizontal conveyor type apparatus is stopped, and a batch type apparatus capable of miniaturizing the apparatus for fixed position operation is provided.

To provide a heating adjusting means for a printed circuit board which satisfies a temperature profile even in a batch type apparatus.

[0010]

The present invention has achieved the above object by solving the above-mentioned conventional problems by the following means.

That is, according to the present invention, a stationary portion of a printed circuit board is set in a housing, and a heater is provided above and below the stationary portion so as to be vertically adjustable toward the stationary portion. The problem is solved by a solder reflow device for a printed circuit board, which is provided so as to freely adjust the heating temperature of the printed circuit board in the stationary part by adjusting the distance between the heaters.

[0012]

Embodiments of the present invention will now be described with reference to the drawings (FIGS. 1 and 2).
To explain,

Housing 1 (length 1000 mm, width 700 mm, height
1400 mm), the stationary portion 2 of the printed circuit board P is set in the approximate center, and heaters 3 and 4 are provided above and below the stationary portion 2 so as to be vertically adjustable and movable toward the stationary portion 2.
The solder reflow device A for the printed circuit board is provided so as to freely adjust the heating temperature of the printed circuit board P set in the stationary part 2 by adjusting the distance between the stationary part 2 and each heater 3, 4. It is a thing.

More specifically, each part of the above apparatus will be described. The stationary part 2 is set so that the printed circuit board P is installed at the fixed position 2 in the conveyor 2a, the table, and the other housing 1. The printed board P is carried in and installed by the carry-in means 7 such as a conveyor from the carry-in port 5, and the soldered printed board P is selected from the carry-out port 6 by the carry-out means 8 such as a conveyor.

The heaters 3 and 4 are provided with a flat heat generating surface, and the heat generating temperature is constant, or the heat generating temperature can be adjusted high or low by electric operation such as voltage. The vertical adjustment movement of the heater 4 with respect to the stationary portion 2 is arbitrary as long as it is a means for vertically moving the heaters 4 under the control of a computer. The screw shafts 12 and 13 are vertically slidable and vertically screwed back and forth, and the screw shafts 12 and 13 are rotated by motors 14 and 15 controlled by a computer, respectively, and the holders 9 and 10 and the heaters 3 and 4 are rotated. Is installed so that it can be adjusted vertically.

[0016]

The printed circuit board P is carried into the housing 1 from the carry-in port 5 by the carrying-in means 7 such as a conveyor, and the conveyor 2a.
The upper and lower heaters 3 and 4 while being positioned in the stationary part 2 with
Heat with.

If the heat generation temperature of the heaters 3 and 4 is constant, the heating temperature is low if the distance between the printed circuit board P and the heaters 3 and 4 is large, and if the distance is small, the heating temperature is high.

The distance between the heaters 3 and 4 and the printed circuit board P of the stationary unit 2 is adjusted by moving the heaters 3 and 4 up and down. The vertical movement is performed by rotating the motors 14 and 15 (eg, stepping motors). The screw shafts 12 and 13 are respectively rotated to vertically move the holders 9 and 10 of the shutters 3 and 4 along the guide shaft 11.

The heating of the printed circuit board P by the heaters 3 and 4 is performed, for example, according to the temperature profile shown in FIG. Therefore, preheating for a set time (volatilization of various solvents, liquefaction of flux) is performed at a low temperature by keeping a large distance between the heaters 3 and 4 and the printed circuit board P,

Subsequently, the heaters 3 and 4 are moved by a fixed distance at every set time, or the distance between the heaters 3 and 4 is gradually reduced intermittently or continuously to adjust the heating according to the temperature profile. Done,

Finally, the heating temperature is raised until the solder is melted, soldering is performed, then the distance between the two is increased, and the cooling process is started.

The above-mentioned operation is performed when the heat generation temperature of the heater is constant, but when a heater whose heat generation temperature can be changed by electric adjustment or the like is used, more precise and varied temperature adjustment can be performed. .

The printed circuit board P having been soldered is conveyed from the stationary section to the carry-out port 6 by the conveyor 2a, and is conveyed to the next step or the like by the conveyor of the carry-out means 8.

[0024]

[Effect] Unlike the conventional method of soldering by heating the printed circuit board in the process of continuous conveyance on a conveyor,
The batch type device heats and heats the printed circuit board at a fixed position, and the heat treatment means for the printed circuit board is performed by freely adjusting the distance between the circuit board and the heater. Along with the miniaturization, the temperature profile from preheating of the printed circuit board to solder welding can be set extremely freely, and as a result,
High-precision soldering can be performed.

Besides the heater having a constant heat generation temperature,
By using the one whose heat generation temperature can be adjusted freely, it becomes possible to adjust the heating temperature with higher accuracy, and therefore, it is possible to set an ideal temperature profile and surely implement it.

Since the batch system is adopted, the device, that is, the housing can be downsized, the installation space can be remarkably reduced, and the cost of the device can be remarkably reduced.

As a matter of course, the apparatus of the present invention is not limited to the above-mentioned printed circuit board, but the fixed parts of various works are set in the housing, and the heaters are provided above and below the fixed parts with the fixed parts interposed therebetween. Prepared for vertical movement toward
By adjusting the distance between the stationary part and each heater,
It can also be used as an adjusting and heating device for various works, which is provided so as to freely adjust the heating temperatures of various works in the stationary part.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a schematic configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view.

FIG. 3 is a front perspective view and a side view showing a schematic configuration of a conventional device.

FIG. 4 is a diagram of a temperature profile.

[Explanation of symbols]

 A device of the present invention P printed circuit board 1 housing 2 stationary part 2a conveyor 3 heater 4 heater 5 carry-in port 6 carry-out port 7 carry-in means 8 carry-out means 9 holder 10 holder 11 guide shaft 12 screw shaft 13 screw shaft 14 motor 15 motor a conventional device 101 Housing 102 Conveyor 103a, 10b, 103c, 103d Heater 104 Carrying In 105 Carrying Out

Claims (4)

[Claims] 1. A fixed part of a printed circuit board is set in a housing, and heaters are provided above and below the fixed part so as to be vertically adjustable toward the fixed part, and between the fixed part and each heater. A solder reflow device for printed circuit boards, which is provided to freely adjust the heating temperature of the printed circuit board in the stationary part by adjusting the distance. 2. The stationary unit is set to a conveyor, a table, or any other device that installs a printed circuit board at a fixed position in a housing, and the printed circuit board is carried into the stationary unit from a carry-in port by a conveyor or other carrying-in means. The solder reflow device for a printed circuit board according to claim 1, wherein the soldered printed circuit board is provided so as to be selected from a carry-out port by a conveyor or other carrying-out means. 3. The heater is provided with a flat heat generating surface, and the heat generating temperature is constant or the heat generating temperature can be adjusted to a high or low level. The vertical movement of the heater with respect to the stationary portion is controlled by a computer. It is arbitrary as long as it is a means for adjusting and moving each vertically in the vertical direction. The solder reflow device for a printed circuit board according to claim 1, wherein the holder and the heater are provided so as to vertically adjust movement by being rotated by a motor controlled by. 4. Not only a printed circuit board but also a stationary part for various works is set in a housing, and a heater is provided above and below the stationary part so as to be vertically adjustable and movable toward the stationary part. A work adjusting and heating device provided so as to freely adjust the heating temperature of various works in the stationary part by adjusting the distance between the stationary part and each heater.