JP3129886B2 - 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 reflow apparatus.

[0002]

2. Description of the Related Art As a conventional reflow apparatus, as shown in FIG. 4, one centrifugal blower 2 is disposed on a central axis of a reflow furnace 1, and the wind generated in the horizontal direction by the centrifugal blower 2 is controlled by a left and right direction. Is guided upward by the guide plate 3 and the wind turned downward in the upper part of the furnace is heated by the heater 4 to a temperature higher than the reflow temperature, the hot air is applied to the work (component mounting board) W, and the convective heat is transmitted to the work W. A reflow device for reflowing solder paste is known.

[0003]

In this type of reflow apparatus, it is desirable to uniformly heat the entire work.
The wind generated in the horizontal direction from the centrifugal blower 2 on the central axis of the reflow furnace 1 blows up while turning horizontally in the passage between the left and right guide plates 3 and the inner wall surface of the furnace. Therefore, the positions and directions in which the hot air is strongly applied on the left and right surfaces of the work do not match, and the left and right surfaces of the work are not uniformly heated. This is considered to be one of the causes of the occurrence of poor soldering.

[0004] The present invention has been made in view of such a point, and an object of the present invention is to provide a reflow apparatus capable of uniformly heating the left and right surfaces of a work.

[0005]

SUMMARY OF THE INVENTION The present invention provides a furnace body ,
Work transfer for loading and unloading work into the furnace
Conveyor and work transfer below this conveyor
A rotation axis horizontally installed in the horizontal direction that intersects the direction,
One rotating shaft is used as a common rotating shaft and attached to the left and right furnace inner wall surfaces.
And a pair of centrifugal blowers
Wind generated from the peripheral surface of the machine rises along the inner wall of the furnace
And lower the wind that has joined at the center of the furnace.
Guide plates on the left and right, and above the conveyor
Heating unit that heats the wind that is
The wind that has passed through the knit and this heating unit and work is 2
On the mutually opposing sides of the pair of centrifugal blowers
Sucked formed symmetrically to heat the workpiece being conveyed lowered joins the wind generated from the peripheral surface of the centrifugal blower at elevated furnace central portion along the furnace wall surface of the left <br/> right a reflow apparatus of the configurations and a pair of hot air circulation system which is.

[0006]

According to the present invention, the lower side of the conveyor for transferring the work is provided.
Horizontal in the horizontal direction that intersects the workpiece transfer direction.
One rotating shaft as a common rotating shaft on the inner wall of the left and right furnace
The wind generated from the peripheral surfaces of a pair of centrifugal blowers provided directly blows upward in the open furnace because it has directionality in the direction perpendicular to the rotation axis, and is guided to the left by the left and right guide plates.
Ascending along the right furnace inner wall and
Do not swivel horizontally when descending . further,
The pair of centrifugal blowers are equally rotated in the same direction at the same speed by a common rotating shaft. Therefore, symmetric hot air convection is formed in the furnace, and the left and right surfaces of the workpiece being conveyed are uniformly heated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS.

FIG. 1 shows the entire structure of a reflow soldering apparatus, in which a furnace body 12 is provided inside an apparatus body 11, and left and right guide plates 13 are provided inside the furnace body 12. A heating unit 14 is arranged above the 13.

A lid 16 is provided on the upper part of the apparatus main body 11 by a hinge 15.
The furnace body upper part 12a detachable from the furnace body 12 is integrally attached to the lid body 16 by a connecting member (not shown), and the heating unit 14 is connected to the furnace body upper part 12a (not shown). They are integrally attached by members.

Therefore, when the lid 16 of the apparatus main body 11 is opened, the heating unit 14 is also opened on the guide plate 13.
This is convenient for maintenance of the heating unit 14 and manual adjustment of the amount of infrared irradiation described below.

The heating unit 14 has a plurality of sheathed heaters 22 mounted between the left and right portions of a frame 21.
A heating device for performing reflow soldering of the component mounting board by forced convection heat generated by hot air that has passed through the heater 22 is provided with an infrared controller 23 described below below each heater 22. Further, a punching plate (perforated plate) 24 is attached to the upper portion of the frame 21 for the purpose of equalizing the amount of air sent to the heater 22.

A substrate transport conveyor 31 is arranged below the heating unit 14. In this conveyor 31, a pair of left and right conveyor frames penetrating the furnace through a substrate loading or unloading opening 32 are arranged in parallel, and endless chains are elongated along the left and right conveyor frames, respectively. The component mounting board W as a work is transported horizontally in a state of being bridged between the chains.

A temperature sensor 33 such as a thermocouple for controlling the power supply to the heater 22 to control the furnace temperature is inserted below the substrate transfer conveyor 31.

At the lower part of the furnace body 12, one rotating shaft 34 is rotatably mounted horizontally, and a pair of left and right centrifugal blowers (sirocco fans) 35 using the one rotating shaft 34 as a common rotating shaft.
Are symmetrically arranged below the left and right guide plates 13 with respect to the center of the furnace body. The rotating shaft 34 is driven by a motor 37 via a belt transmission mechanism 36. By controlling the rotation speed of the motor 37, the centrifugal blower 35
Controls the amount of air circulated in the furnace.

The furnace atmosphere sucked into the left and right centrifugal blowers 35 from the central part of the furnace is discharged between the left and right inner wall surfaces of the furnace body 12 and the left and right guide plates 13 and the passage therebetween. From the upper part of the heating unit 14 and heated by a heater 22 through a punching plate 24, and an infrared controller 23 to be described later.
, And the solder paste of the substrate W is reflowed by forced convection heat, and the left and right centrifugal blowers 35 are again blown.
Sucked into.

In such a pair of left and right hot air circulating systems, the wind generated from the peripheral surfaces of the left and right centrifugal blowers 35 rotated by the rotating shaft 34 provided in the lower part of the inside of the furnace is rotated by the rotating shaft 34.
Therefore, it is blown upward in the open furnace because it has a directionality in a direction perpendicular to the direction, and is not swirled in the horizontal direction. In addition, since the pair of left and right centrifugal blowers 35 are equally rotated in the same direction at the same speed by the common rotating shaft 34,
A symmetrical hot air convection is formed in the furnace, and the left and right surfaces of the substrate W conveyed in a direction perpendicular to the plane of FIG.

At the bottom of the furnace body 12, a perforated nozzle 38 for blowing cold air to the substrate W is provided. The blowing of the cool air from the multi-hole nozzle 38 is necessary when a low melting point solder is used for the substrate W, when components on the lower surface of the substrate are protected from high heat, when the temperature in the furnace is forcibly reduced, and the like.

Next, as shown in FIG. 2, the heating unit 14 includes a plurality of sheathed heaters 22 arranged at predetermined intervals in the frame 21, and rectifying plates 41 on both sides of each heater 22. Is provided.

Further, a pair of rotating shafts 43 are arranged below the heaters 22 via one infrared transmitting portion 42 for each heater, and the rotating shaft 43 passing through each infrared transmitting portion 42
The infrared control bodies 23 facing each other are attached. Each of the rotating shafts 43 has a regular hexagonal cross section at a mounting portion of the infrared control body 23, but is rotatably fitted to the frame 21 at a circular cross section.

Arms 44 indicated by solid lines are integrally attached to a rotary shaft 43 located at the lower right of each heater 22, and each arm 44 is rotatably mounted on a common interlocking link 45. The rotation shaft 43 located at the lower left of each heater 22 has
Arms 46 indicated by dotted lines are integrally attached, and each arm 46 is also rotatably mounted on a common interlocking link 47.

When one of the interlocking links 45 and the other interlocking link 47 are moved in mutually opposing directions manually or by an actuator such as a solenoid or an air cylinder (not shown), the opposing infrared control bodies 23 It is rotated in the opposite direction to open and close, and in a closed state, shields infrared rays emitted from the heater 22.

Further, a hot air control body 48 which is opposite to the infrared control body 23 and is opposed to each other is attached to each common rotating shaft 43 provided with each infrared control body 23. The hot air control body 48 controls the amount of hot air passing by rotating in the closing direction by the amount that each infrared control body 23 rotates in the opening direction.

Then, as shown in FIG. 3A, by opening the infrared ray control body 23, the infrared ray IR generated from the heater 22 is irradiated on the substrate through the infrared ray transmitting section 42 and is heated by the heater 22. The heated hot air is blown onto the board through the infrared transmitting section 42, and the component mounting board is reflow-heated by using both radiant heat by infrared IR and forced convection heat by hot air. At this time, the hot air control bodies 48 facing each other are rotating in the direction of limiting the air volume.

Further, as shown in FIG. 3B, the infrared rays emitted from the heater 22 to the lower side are shielded by closing the infrared controllers 23 facing each other below the heater 22. At this time, since the hot air control bodies 48 facing each other are fully opened, the component mounting board is reflow-heated by the forced convection heat of the hot air passing between the hot air control bodies 48 facing each other.

As described above, even when the infrared control body 23 is closed and heated only by hot air, or when the infrared control body 23 is opened to use both infrared radiation heat and forced convection heat, the same rotation as the infrared control body 23 is performed. The hot air control bodies 48 attached to the shaft 43 so as to face each other rotate in the closing direction by the amount of rotation of the infrared control bodies 23 in the mutually opening direction, and also rotate in the closing direction of the infrared control bodies 23. Rotation in the opening direction is performed by the amount of rotation in the closing direction, and control is performed so that the amount of hot air passage does not change much.

[0026]

According to the present invention, a conveyor for transporting a workpiece is provided.
Left and right crossing the work transfer direction below
Left and right with one rotating shaft horizontally installed in the direction as a common rotating shaft
The wind generated from the peripheral surfaces of a pair of centrifugal blowers provided along the furnace inner wall surface is blown directly upward in the open furnace because it has a direction perpendicular to the rotation axis. , Left and right plan
The inner plate rises along the inner wall of the furnace
When descending joins the body central portion, since there you to swivel in the horizontal direction and each at the bottom of a pair of hot air circulation system arranged pair of centrifugal blowers constant velocity cutlet by a common rotation axis Since it is rotated equally in the same direction, symmetrical hot air convection can be created in the furnace, and the left and right surfaces of the work can be uniformly heated to perform good reflow soldering and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a reflow apparatus of the present invention.

FIG. 2 is a sectional view showing a heating unit in the reflow device.

FIG. 3 is a sectional view showing the operation of the heating unit.

FIG. 4 is a sectional view of a conventional reflow device.

[Explanation of symbols]

12 Furnace body 13 Guide plate 14 Heating unit 31 Conveyor 34 Rotary shaft 35 Centrifugal blower W Substrate as work

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Futaki Masuda 11-1, Kamihirose Higashikubo, Sayama City, Saitama Prefecture, Japan Inside the Kiko Factory (72) Inventor Nobuhide Abe 591, Kamihirose Higashikubo, Sayama City, Saitama Prefecture No. 11 Inside the machine plant of Tamura Seisakusho Co., Ltd. (56) References JP-A-3-77773 (JP, A) JP-A-1-186270 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) H05K 3/34 B23K 1/008

Claims (1)

(57) [Claims] 1. A furnace body and a work to be carried in and out of the furnace body.
Conveyor crosses and intersects the work transfer direction below this conveyor
And a single rotating shaft as a common rotating shaft attached to the left and right inner wall surfaces.
And a pair of centrifugal blowers, and the air generated from the peripheral surfaces of these centrifugal blowers
Raised along the wall and joined at the center of the furnace
Left and right guide plates for guiding the wind to descend, and arranged above the conveyor to be sprayed on the workpiece
The heating unit that heats the wind that is blown, and the wind that has passed through this heating unit and the work
A pair of centrifugal blowers are sucked into the sides facing each other.
A pair of symmetrically formed hot air circulations, in which wind generated from the peripheral surfaces of these centrifugal blowers rises along the inner wall surfaces of the right and left furnaces, joins at the center of the furnace body, descends, and heats the work being transported reflow apparatus characterized by comprising a system.