JPH07108454B2 - Reflow heating device - 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 heating device used for reflow soldering.

[0002]

2. Description of the Related Art As a conventional reflow heating device, as shown in FIG. 4, inside a reflow furnace 1, an air flow generated by a blower 2 is circulated along a guide plate 3 while being heated by a heater 4. A stand-alone heating device that blocks infrared rays emitted and applies only the air (hot air) heated by the heater 4 to the component mounting board W and transfers the forced convection heat to the board W to reflow the solder paste. 61-
As disclosed in Japanese Patent No. 289697, a combined heating device for reflow soldering a component mounting board by using radiant heat transfer by infrared rays emitted from a heater and forced convection heat transfer by hot air passing through the heater is generally used. Known to be.

The independent heating device using only the hot air has advantages such as excellent uniformity of temperature distribution, a small temperature difference between each part of the board, and soldering at low temperature. Since it takes time, the temperature of the component body mounted on the board becomes high as well as the temperature of the board.

The combined heating device of radiant heat and forced convection heat is capable of rapid heating by infrared radiant heat and has an advantage that the temperature of the component body is less likely to rise above the temperature of the substrate. Since the amount of infrared absorption differs depending on the color, there are drawbacks such as a temperature difference being likely to occur and the reflow temperature being high.

[0005] The user selects and purchases the one that can secure an ideal temperature profile for the reflow soldering of his / her own component mounting board from the heating device of only the hot air or the combination heating device. .

[0006]

Thus, at first, an ideal temperature profile can be secured by a heating device of a type corresponding to the board, but the target of reflow soldering is a completely different type of component of a new product. When the substrate is changed to an on-board substrate, an expensive heating device cannot be easily replaced, so that production is often continued with an unsatisfactory temperature profile that does not match the changed substrate.

The present invention has been made in view of the above points, and a heating method mainly including forced convection heat by hot air and a heating method in which radiant heat by infrared irradiation are used in combination are simply provided as needed. It is an object of the present invention to provide a reflow heating device capable of appropriately responding to the change of the reflow soldering work by making it possible to switch to the above.

[0008]

The invention according to claim 1 is conveyed along the heater 22 by radiant heat transfer by infrared rays emitted from the heater 22 and forced convection heat transfer by hot air passing through the heater 22. In the heating device for reflow soldering the work W, the infrared controller 23 for controlling the infrared irradiation amount is provided between the heater 22 and the work W so as to be openable and closable.

According to the second aspect of the invention, radiant heat transfer by infrared rays emitted from a plurality of heaters 22 arranged at predetermined intervals and forced convection heat transfer by hot air passing through each heater 22 In a heating device for reflow soldering a work W conveyed along a heater 22, a pair of rotating shafts 43 arranged between the heaters 22 and the work W, and one heater interposed via an infrared transmitting portion 42. A plurality of infrared control bodies 23 that are attached to face each other and that open and close by rotating the rotating shafts 43 arranged via the infrared transmitting portion 42 in mutually opposite directions to control the infrared irradiation amount; The infrared control bodies 23 are mounted so as to face each other on respective rotary shafts 43 that are common to each other, and the infrared control bodies 23 rotate in mutually opening directions, so that they rotate in mutually closing directions to control the hot air passage amount. Multiple hot air controls 48 A reflow heating apparatus having a.

[0010]

According to the invention described in claim 1, by closing the infrared control body 23 between the heater 22 and the work W,
The infrared rays irradiated to the work W are limited, and the work W is reflow-heated mainly by the forced convection heat of hot air. Also,
The work W is reflow-heated by using the infrared radiation heat and the forced convection heat together by opening the infrared control body 23.

According to a second aspect of the invention, the infrared control body 23
When the infrared control body 23 is closed and heated mainly by hot air, or when the infrared control body 23 is opened and infrared radiant heat and forced convection heat are used together, the infrared control body 23 and the common rotary shaft 43 are mounted to face each other. The hot-air control bodies 48 rotate in the mutually opening directions of the infrared control bodies 23, and rotate in the mutually closing directions. Further, the hot air control bodies 48 rotate in the mutually closing directions of the infrared control bodies 23, respectively. Rotate in the opening direction to control so that the hot air passage amount does not change so much.

[0012]

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

FIG. 2 shows the entire structure of the reflow soldering apparatus. An outer furnace body 12 is provided inside the apparatus main body 11, an inner furnace body 13 is provided inside the outer furnace body 12, and an inside thereof is provided. A heating unit 14 is arranged above the furnace body 13. A lid 16 is openably and closably attached to an upper portion of the apparatus main body 11 by a hinge 15, and a separable upper portion 12a of the outer furnace body 12 is integrally attached to the lid body 16 by a connecting member (not shown). The heating unit 14 is integrally attached to the upper part 12a of the body by a connecting member (not shown).
Therefore, when the lid 16 of the apparatus main body 11 is opened, the heating unit 14 is also opened on the inner furnace body 13, so that maintenance of the heating unit 14 and manual adjustment of the infrared irradiation amount described later are performed. It is convenient for

The heating unit 14 has a plurality of sheathed heaters 22 mounted between the left and right portions of the frame 21, and the radiant heat of infrared rays emitted from each heater 22 and each heater.
It is a heating device for reflow soldering a work by forced convection heat by hot air that has passed through 22.
An infrared control body 23, which will be described later, is provided below 22.
Further, a punching plate (perforated plate) 24 is attached to the upper part of the frame 21 for the purpose of equalizing the amount of air sent to the heater 22.

A substrate transfer conveyor 31 is arranged below the heating unit 14. In this conveyor 31, a pair of left and right conveyor frames that penetrate the inside of the furnace through an opening 32 for loading or unloading a substrate are arranged in parallel, and endless chains are provided along the left and right conveyor frames, respectively. The component-carrying substrate W, which is a workpiece to be soldered, is horizontally conveyed between the chains.

Below the substrate conveyer 31, a temperature sensor 33 such as a thermocouple for controlling the electric current to the heater 22 to control the temperature inside the furnace is inserted.

A common rotary shaft is provided on the left and right sides of the inner furnace body 13.
A pair of sirocco fans 35 provided in 34 are provided. The rotating shaft 34 is connected to a motor 37 via a belt transmission mechanism 36.
Driven by. By controlling the rotation speed of the motor 37, the amount of air inside the furnace circulated by the sirocco fan 35 is controlled.

Then, the air sucked from the central portion of the furnace by the sirocco fan 35 is supplied to the outer furnace body 12 and the inner furnace body.
13 is discharged between the heating unit 14 and rises, and heated by the heater 22 from the upper part of the heating unit 14 through the punching plate 24,
The solder paste on the substrate W is reflowed by forced convection heat after being sprayed onto the substrate W via an infrared control body 23 described later.

A perforated nozzle 38 for blowing cold air onto the substrate W is provided at the bottom of the outer furnace body 12. The blowing of cold 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 inside the furnace is forcibly lowered, and the like.

Next, as shown in FIG. 1, in the heating unit 14, the plurality of sheathed heaters 22 are arranged at predetermined intervals in the frame 21, and air straightening plates are provided on both sides of each heater 22. 41 are provided.

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

An arm 44 shown by a solid line is integrally attached to a rotary shaft 43 located at the lower right of each heater 22, and each arm 44 is rotatably attached to a common interlocking link 45. Further, the rotary shaft 43 located at the lower left of each heater 22 has two
Arms 46 indicated by a chain line are integrally attached, and each arm 46 is also rotatably attached to a common interlocking link 47.

When the interlocking link 45 on one side and the interlocking link 47 on the other side are moved in directions opposite to each other manually or by an actuator such as a solenoid or an air cylinder (not shown), the infrared control bodies 23 facing each other are moved to each other. The infrared rays emitted from the heater 22 are shielded in the closed state by being rotated in the opposite direction to open and close.

Further, hot air control bodies 48 facing each other on the opposite side of the infrared control bodies 23 are attached to the common rotary shafts 43 provided with the infrared control bodies 23. The hot air control body 48 rotates in a direction in which the infrared control bodies 23 rotate in a mutually opening direction, and thus rotates in a mutually closing direction to control the hot air passing amount.

Then, as shown in FIG. 3A, by opening the infrared control body 23, the infrared IR generated from the heater 22 is applied to the substrate through the infrared transmitting portion 42 and heated by the heater 22. The hot air is blown to the board through the infrared transmitting section 42, and the component mounting board is reflow-heated by using the radiant heat of the infrared IR and the forced convection heat of the hot air together. 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 radiated downward from the heater 22 are shielded by closing the infrared ray control bodies 23 facing each other under the heater 22. At this time, since the hot air control bodies 48 facing each other are in the fully open state, 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, when the infrared control body 23 is closed and heated only by hot air, or when the infrared control body 23 is opened and infrared radiant heat and forced convection heat are used together, rotation common to 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 mutually opening directions of the infrared control bodies 23, and thus rotate in the mutually closing directions. The amount of hot air passage is controlled so that the amount of hot air passing does not change so much by turning in the direction of opening by the amount of turning in the direction of closing.

[0028]

According to the invention described in claim 1, in a heating device that uses both radiant heat by infrared irradiation and forced convection heat by hot air, infrared rays for controlling the infrared irradiation amount between the heater and the work. Since the control body is openable and closable, it is possible to easily switch between the heating method that mainly uses forced convection heat from hot air and the heating method that uses radiant heat from infrared irradiation to change the work. Appropriate handling is possible, and one heating device can provide an optimum temperature profile for a plurality of types of works.

According to the second aspect of the present invention, since the infrared control body and the hot air control body are mounted on the rotary shaft so that the opening and closing of the infrared control body and the hot air control body are reversed, the hot air passage amount does not change even if the infrared irradiation amount is variably controlled. It can be maintained so as not to fluctuate, and the effect of the invention of claim 1 can be secured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a reflow heating device of the present invention.

FIG. 2 is a cross-sectional view of a reflow type soldering device including the same heating device.

FIG. 3 is a cross-sectional view showing the operation of the above heating device.

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

[Explanation of symbols]

 W Work 22 Heater 23 Infrared control body 42 Infrared transmission part 43 Rotation axis 48 Hot air control body

Front Page Continuation (72) Inventor Niki Masuda 11 at 591 Kamihirose Higashikubo, Sayama City, Saitama Prefecture Tamra Manufacturing Co., Ltd. at a machinery factory (72) Inventor Nobuhide Abe 11 shares at 591 Kamihirose Higashikubo, Sayama City, Saitama Prefecture Company Tamura Seisakusho Co., Ltd., in a mechanical engineering factory (56) References JP-A-2-30372 (JP, A) JP-A-61-289697 (JP, A) JP-A-63-278668 (JP, A)

Claims (2)

[Claims] 1. A heating device for reflow soldering a work conveyed along a heater by radiant heat transfer by infrared rays emitted from a heater and forced convection heat transfer by hot air passing through the heater, wherein the heater and the work are The reflow heating device is characterized in that an infrared control body for controlling the infrared irradiation amount is provided between the two so as to be openable and closable. 2. A work conveyed along each heater is transferred by radiant heat transfer by infrared rays emitted from a plurality of heaters arranged at a predetermined interval and forced convection heat transfer by hot air passing through each heater. In a heating device for reflow soldering, a pair of rotating shafts arranged between the heaters and the work, each of which is provided with an infrared transmitting portion between the heaters, are attached so as to face each other, and the infrared transmitting portion is provided therebetween. A plurality of infrared control bodies that open and close by rotating the arranged rotary shafts in opposite directions to control the infrared irradiation amount, and are mounted on the rotary shafts common to the respective infrared control bodies so as to face each other, A heating apparatus for reflow, comprising: a plurality of hot air control bodies for controlling the amount of hot air passage by rotating in a direction in which each infrared control body rotates in a mutually opening direction and rotating in a mutually closing direction. .