JPS59174272A - Reflow furnace - Google Patents

Abstract

PURPOSE:To solder a work placed with parts on a base plate with excellent operability without damaging the parts on account of overheating in the stage of soldering said work by heating, soldering and cooling the work while conveying the same with a rotary table. CONSTITUTION:A rotary table 20 attached with plural work brackets 30 and a water tank 50 for cooling are attached on a base plate 10. A heater 40 and a cooling fan 70 are installed above the same. A work to be soldered is loaded on the bracket 30 in a position A, then the table 20 is rotated to move the work to a point C, where the tank 50 is risen and while the work is cooled from below, the top surface thereof is heated by a preheater 41 using IR rays and a main heater 42 to melt the solder and to solder the parts to the base plate. The soldered part is further cooled to solidify by the fan 70. The work is removed from the bracket 30 in the position B. The work is soldered with excellent operability without being damaged by overheating of the work.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a reflow oven for removing soldering.

(B) Prior art In general, in the production of hybrid ICs, etc., parts such as chip parts and ICs are placed on a board on which paste solder has been placed in advance (hereinafter referred to as the work), and then heated.
The solder is melted, cooled again to harden the solder, and parts and the like are then mounted on the board, and this is the flow chart used at this time.

Conventionally, as this type of reflow oven, a so-called linear type reflow oven has been used in which a workpiece is conveyed linearly by an endless belt, the workpiece is preheated from below during the conveyance, and then heated from above by an infrared heater.

However, in this linear type glue flow system, the preheating heater, infrared heater, cooling fan, etc. must be placed almost in a straight line, which increases the distance from the workpiece loading position to the workpiece unloading position, and the operator The scope of work had to become larger. Also, some of the parts placed on the board, such as ICs and capacitors, have different characteristics.

In some cases, it may be necessary to avoid overheating, and it may be possible to install a water tank to cool such parts, but due to the unique structure of the linear type, the overall configuration of the furnace is complicated. As the size increases, the effectiveness of cooling is also low, so damage to parts is unavoidable.Purpose The purpose of this invention is to reduce the operating range of the operator.
Moreover, it is an object of the present invention to provide a flow system that is small in size and has a simple configuration, which effectively cools parts and prevents damage to them.

2) Structure To achieve the above object, the present invention includes a rotary table having a plurality of work brackets disposed around its periphery for holding a workpiece, and one side of the workpiece held by the workpiece brackets. The workpiece is provided with a heater consisting of a preheating heater and a main heater for heating, and a water tank for cooling the other side of the workpiece during the heating.

1) Embodiment FIG. 1 is a perspective view schematically showing a reflow oven according to the present invention, and FIG. 2 is an enlarged perspective view of the main parts thereof.
0 is a rotary table installed on this base. A drive mechanism for the rotary table 20 is provided inside the base 10. Reference numeral 30 designates a plurality of work brackets disposed on the peripheral edge of the rotary table 20 with, for example, asbestos 31 interposed therebetween. The workpiece bracket 30 is open outward and is configured to hold the workpiece 100 in a detachable manner by clamping or grasping the workpiece 100 therein. And 3
Reference numeral 2 denotes a shielding plate, which is rotatably attached to the work bracket 30 by a hinge 33. Note that this shielding plate 32 may be configured to be detachable from the work bracket 30 when not in use.

40 is a workpiece 100 held by a workpiece bracket 30
This is a heater that heats one surface of the device by irradiating it with infrared rays from above. This heater 40 is composed of a preliminary heater 41 that emits diffused light so that the entire work 100 can be uniformly irradiated, and a main heater 42 that emits concentrated light so that the solder portion of the work 100 can be irradiated intensively.

50 is a workpiece 100 held by a workpiece bracket 30
This is a water tank for cooling the other side of the heater 40 from below, and this water tank is provided almost directly below the heater 40. 51 is water. A sub-tank 52 is provided on the upper side of the water tank 50, and a weir 53 is provided between the sub-tank 52 and the water tank 50. The father-in-law, 55, is a water supply pipe and a drain pipe, respectively. Reference numeral 60 denotes an air cylinder that moves the water tank 50 up and down, and is provided within the base 10. 70 is a cooling fan for cooling the heated workpiece 100. 80 is an exhaust duct. Note that the opening interval of the work bracket 30 may be freely adjustable.

Next, the operations of the flows configured as described above will be explained. For convenience of explanation, it is assumed that the rotary table 20 rotates clockwise, the workpiece 100 is loaded into the workpiece bracket 30 at point A, and the workpiece 100 is taken out at point B.
It is assumed that heating by infrared irradiation is performed at six points.

The rotary table 20 is rotated at a constant speed, and the workpieces 100 are moved one by one or a plurality of them to the workpiece bracket 30 at point A.
to be loaded. When the work 100 approaches the infrared irradiation position C, the air cylinder mark is driven to move the aquarium 50 up and down so that the water surface in the aquarium garden reaches a predetermined height. in this case,
The height of the water surface in the tank is kept constant by a weir 53.

That is, even if the water 51 evaporates due to irradiation with infrared rays, water is supplied through the water supply pipe 54 and excess water is drained through the drain pipe 55. For example, the performance of the capacitor 101 will not be affected even if it is immersed in water, but the performance of the thermistor and coil may deteriorate if immersed in water.
Since such parts become unusable, the bottom surface of the board (
If the water tank 50 is installed on the aquarium side), move the aquarium 50 downward. Further, when parts with weak heat resistance such as the IC 102 are provided on the upper surface (irradiation side) of the substrate, only the main body of the IC 102 is shielded by the shielding plate 32.

Thus, the workpiece 100 is heated by the diffused light of the preheater 41.
The entire area is uniformly irradiated, and then the solder portion of the workpiece 100 is intensively irradiated by condensing light from the main heater 42 to melt the paste solder that has been placed on the workpiece 100 in advance.

Water vapor and other gases generated at this time are exhausted through the exhaust duct 80. The workpiece 100, which has been cooled by the cooling fan 70 and has become solidified with solder, is taken out from the workpiece bracket 30 at point B.

Note that by freely adjusting the opening interval of the work bracket 30, substrates of various sizes can be handled.

(f) Effects As detailed above, in this invention, the workpiece 100 is transported by the rotary table 20, so that
Loading or unloading of workpieces into or out of the workpiece bracket 30 can be performed in very close proximity. Therefore, the work range of the operator can be reduced. In addition, if the distance required from loading to unloading the workpiece is the same as the conventional linear type, the distance required is only the diameter of the rotary table, so the area required for installation can be significantly reduced, and the reflow oven can be made smaller. . Further, since the work bracket 30 is provided on the peripheral edge of the rotary table 30, and the heater and water tank can be installed at specific locations around the circumference of the rotary table, the structure is simplified. The heater that heats the workpiece consists of a preheating heater and a main heater, so it is possible to heat the workpiece too quickly and damage it.
No more deterioration. Furthermore, since a water tank is provided, parts attached to the bottom surface of the workpiece can be effectively cooled down if necessary. Furthermore, for parts that would deteriorate if directly irradiated with infrared rays, a shielding plate is provided on the work bracket, thereby making it possible to shield the parts.

Therefore, the reflow oven according to the present invention has the effect of efficiently mass-producing high-quality products.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts thereof. 30... Rotating table, 30... Work bracket, 33... Shielding plate, 40... Heater, 41... Preheating heater, 42... Main heater, 50... Water tank, 100... = work.

Claims (2)

[Claims] (1) A rotary table having a plurality of work brackets arranged around its periphery for holding a work, and a preheating heater and a main heater that heat one side of the work while it is held by the work brackets. and a water tank for cooling the other side of the work during the heating. (2) The glue flow system according to claim 1, wherein the work bracket has a structure to which a shielding plate can be attached.