JP2003188524A - Reflow apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a reflow apparatus wherein even when there are a large difference between heat capacities or heat transfers of parts to be mounted, the parts are uniformly heated for secure soldering by making use both conduction heating by hot air and direct heating by radiation energy. <P>SOLUTION: In a reflow apparatus 10 according to one embodiment, a workpiece board P held horizontally in a heating furnace section 15 can be directly heated with hot air Fa flowing in parallel to the workpiece board P produced in an air feed section 12, a gas heating section 13, and a gas rectifier section 14, additionally, the workpiece board P can be heated with radiation energy of a plurality of small-sized far infrared heaters 151 supported movable vertically by a vertical motion driving apparatus 20A above the heating furnace section 15, and with radiation energy of a lower far infrared heater 152 disposed below the workpiece substrate P at need. The temperature of the individual small-sized far infrared heaters 151 and the temperature of the lower far infrared heater 152 are controlled with a control section 19 such that they form a temperature profile of the workpiece substrate P. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow apparatus used for mounting components on an electronic circuit board, and more particularly to improvement of a heating means thereof.

[0002]

2. Description of the Related Art First, an outline of a conventional reflow apparatus will be described with reference to FIGS.

FIG. 10 is a conceptual block diagram of a reflow device according to the first embodiment of the prior art, FIG. 11 is a schematic diagram showing the flow of hot air blown from the reflow device shown in FIG. 10, and FIG. 12 is a prior art. Temperature profile when the substrate to be processed is heated by the reflow device of FIG. 13, FIG. 13 is a conceptual configuration diagram of the reflow device of the second embodiment of the prior art, and FIG. 14 is a convection state of hot air in the reflow device shown in FIG. FIG.

As shown in FIG. 10, the conventional reflow apparatus 50 is divided into a plurality of heating zones which constitute a preheat zone and a reflow zone, and a plurality of heating units 51 provided in these plurality of heating zones. And a jetting hole 52 which is arranged between these heating units 51 and blows out hot air downward, and a belt conveyor which carries the substrate P to be processed below the infrared heater 51 and the jetting holes 52 and continuously conveys it. 53 and the like are arranged.

Here, the substrate P to be processed is a substrate on which various electronic components such as size and function and mechanical components are mounted on an electronic circuit substrate via an adhesive material, for example, cream solder, It is a semi-finished product in which the component is fixed on the circuit of the electronic circuit board by heating, melting, and cooling the cream solder by using the reflow device 50.

Therefore, the substrate P to be processed is transferred to the belt conveyor 5
As it passes through the heating units 51 and the ejection holes 52 from upstream, the cream solder is gradually heated by 3, and the cream solder on the electronic circuit board is melted and soldered.

In this case, as shown in FIG. 11, the hot air flows from the ejection holes 52 to the substrate P to be processed, and the hot air hits the substrate P to be processed and stagnates (stagnation point a) at the portion indicated by the symbol a. Then, the hot air hitting the substrate P to be processed flows as a wall jet along the substrate P to be processed (wall jet region b).

At this time, the heat transfer coefficient is high at the stagnation point a and low in the wall jet region b flowing along the substrate P to be processed, which is considered to be one of the causes of the temperature variation. ing.

At present, in order to improve this point, in the reflow apparatus 50, the heating effective area of the heating unit 51 is increased to increase the heat transfer coefficient, and at the same time, the heating time is lengthened, so that the substrate P to be processed is increased. Due to the heat conduction, the temperature variation of the entire substrate P to be processed is converged. For this reason, the heating section becomes large and the heating time becomes long, which causes a problem that the entire apparatus becomes large or long.

On the other hand, when the heating condition of the substrate P to be processed is viewed from the time and the change in temperature depending on the position on the substrate P to be processed, the substrate P to be processed is continuously conveyed in the apparatus by the conveying means of the belt conveyor 53. Therefore, the temperature of the upstream portion of the substrate to be processed P first rises, and the temperature of the downstream portion begins to rise later by the speed of the belt conveyor 53. Further, the heat generated by heating in the upstream portion is transferred in the downstream direction due to the heat conduction of the substrate P to be processed. In the downstream portion, the heat transmitted by the heat conduction is added, and the temperature is likely to be higher than the temperature in the upstream portion, so that a temperature variation occurs in the substrate P to be processed as in the temperature profile shown in FIG. Dots occur.

A reflow device for eliminating the above-mentioned uneven heating is disclosed in JP-A-9-237965.
As shown in FIG. 13, the reflow device 60 according to the second embodiment of the related art is a heating system in which hot air is convected in the longitudinal direction of the furnace body 61, which is divided into a plurality of first preheat zones and second preheat zones. A zone and a heating zone where hot air convection is provided in the width direction of the furnace body 61 like the reflow zone, a plurality of infrared heaters 62 are arranged in the former heating zone, and a plurality of infrared heaters 63 are arranged in the latter heating zone. , A hot air blowing nozzle 64 for injecting hot air downward at the inlet of the substrate P to be processed, and a hot air blowing nozzle 65 for injecting hot air downward at the reflow zone, and the infrared heaters 62, 63 and hot air. A belt conveyor 66 is arranged so that the substrate P to be processed can be conveyed below the blowing nozzles 64 and 65. Hot air blower 67,6
The air blown from 8 is generated by heating with the heaters 69 and 70, respectively, and is blown to the substrate P to be processed from the hot air blowing nozzles 64 and 65.

When soldering components with the reflow device 60 thus constructed, as shown in FIGS. 13 and 14, the substrate P to be processed is placed and the belt conveyor 66 is placed.
At the upstream side of the first preheat zone, the hot air blowing nozzle 64 disposed above the first preheat zone blows down the hot air Hv perpendicularly to the surface to be heated of the substrate P to be processed, and the substrate P to be processed P Furnace body 6 caused by hitting
1. The surface to be heated is heated by the hot air component Hc that convects in the longitudinal direction of 1 and is heated by the infrared heater 62 in each zone to be preheated, and then is carried into the reflow zone to be processed from the hot air blowing nozzle 65. The hot air Hv is blown down perpendicularly to the surface to be heated of the substrate P, is heated by the hot air component Hc that is generated by contacting the surface to be heated, and convects in the width direction of the furnace body 61, and is also heated by the plurality of infrared heaters 63. Melts the cream solder.

However, since the hot air Hc used in the reflow device 60 is convection, it has no directionality, and therefore the straightness is weak, and the wind speed varies.
The heat transfer rate varies.

For this reason, even if the reflow device 60 is improved, it causes a temperature variation on the surface to be heated of the substrate P to be processed, and it is difficult to uniformly heat the surface to be heated.

In order to solve such a problem, the present applicant has invented the present invention that the heating efficiency is improved and the heat transfer coefficient is uniform, and therefore the temperature on the surface to be heated can be improved. We applied for a soldering method and a device therefor with extremely little variation, as in Japanese Patent Application No. 2001-0777038. The soldering device of the invention (referred to as "reflow device" in this specification)
The main points will be described below with reference to the drawings.

FIG. 15 is a perspective view of a reflow apparatus according to one embodiment of the prior invention, FIG. 16 is a cross-sectional side view of the reflow apparatus shown in FIG. 15 taken along the line AA, and FIG. 17 is a reflow apparatus shown in FIG. 18 is an enlarged cross-sectional view of a portion indicated by an arrow A, FIG. 18 is a partially enlarged cross-sectional view of a modification of the heating furnace portion in the previous reflow apparatus shown in FIG. 15, and FIG. 19 is a heating furnace in the reflow apparatus shown in FIG. 20 is a partially enlarged cross-sectional view of another modification of the portion, FIG. 20 is a curve showing a general temperature profile that can be used in the soldering method of the prior invention, and FIG. 21 is a conventional gas heating portion (reflow furnace). FIG. 22 is a graph of the local heat transfer coefficient on the flat plate in the temperature / velocity boundary layer shown in FIG. 21, when a flat plate is placed on the plate and hot air is flowed.

The reflow apparatus 8 of the prior invention shown in FIG.
0 is a gas rectifying unit 81, a gas heating unit 82, a heating furnace unit 8
3, exhaust part 84, control part 85, hot-air circulation pipe 86, 8
7, 88 and the like are arranged so as to form one circulation path.

A gas supply pipe 89 having an opening / closing valve 891 mounted therein is connected to the hot air circulation pipe 86 (FIG. 16). A gas supply source 20 is connected to the gas supply pipe 89 and is configured so that clean air or an inert gas such as nitrogen gas can be supplied or shut off at any time by opening and closing the open / close valve 891.

As shown in FIG. 16, a fan 811 is incorporated in the gas rectifying section 81, and the fan 811 is incorporated therein.
1 is operated to draw in gas from the hot air circulation path 86, and to the gas heating section 82 and the heating furnace section 83 in parallel with the heated surface of the substrate P to be processed, which will be described later, and with a directional flow. As (rectification), it has a function of supplying at a predetermined speed and air volume.

An electric heater 821 is built in the gas heating section 82 disposed downstream of the gas rectifying section 81 (FIG. 16), and heats the inflowing air to a predetermined temperature to obtain a predetermined hot air Fa. To generate.

The heating furnace portion 83 has a furnace wall 831 having a rectangular cross section.
And is a portion for heating the surface to be heated of the target substrate P carried in from the upstream by the hot air Fa supplied from the gas heating unit 82, and the target substrate to be processed on the lower side surface of the central portion thereof. A P carry-in port 832 is provided, and a carry-out port (not shown) is provided on the opposite side surface. These are closed by a door (not shown) during operation. Further, the conveyor 9 that can carry in and carry out the substrate P to be processed into and from the carry-in port 832 and the carry-out port is perpendicular to the passage of the hot air Fa.
1 is provided. Then, the processed substrate P that has been carried in
Are fastened to the bottom of the heating furnace section 83. The substrate P to be processed is
In the illustrated example, the surface to be heated is placed on the tray T with the surface to be heated facing upward, and the tray T is loaded.

Straightening hot air Fa passing through the heating furnace section 83
Is a straight flow having a wind velocity controlled as described later and parallel to the surface to be heated of the substrate to be processed, and is a turbulent flow. When the wind velocity is low, the hot air Fa is likely to be a laminar flow, the heat transfer coefficient is lower than that of the turbulent flow, and the heated surface cannot be sufficiently heated.

As shown in FIG. 16, the exhaust section 84 has
An exhaust port 841 is opened in a part of the bottom surface thereof, and an open / close valve 842 that is always closed is attached to the exhaust port 841. By opening the open / close valve 842, the hot air Fb used for heating is opened. A part of the gas is exhausted from the circulation path, and the pressure (air volume) in the heating furnace section 83 can be adjusted. When the soldering work is finished, the exhaust port 841 is fully opened to exhaust all the gas.

A microcomputer is built in the control unit 85. Under the control of the microcomputer, the rotation of the fan 811 of the gas rectifying unit 81 is controlled to control the blowing speed, and the gas heating unit 82 is controlled. Electric heater 8
Control means for controlling the current supplied to the electric heater 821 in order to adjust the heating temperature of 21, the on-off valve 8 of the exhaust part 85
The control means for adjusting the opening angle of 42 to adjust the pressure (air volume) in the heating furnace section 83 and the opening / closing valve 891 in the gas supply pipe 89 are opened and closed to supply or stop the supply of gas from the gas supply source 90. A control unit for controlling, a control unit for driving the conveyor 91 to control loading and unloading of the substrate to be processed P, and the like are incorporated.

The hot air circulation pipes 86, 87, 88 are pipes for returning the hot air Fb from the heating furnace portion 83 to the gas rectifying portion 81, and the hot air circulation pipes 86, 87 have a semicircular cross section. The structure of the hot air circulation pipe 88 is formed by a pipe having a rectangular cross section. The gas from the hot air circulation pipe 86 is drawn in by the fan 811 mounted in the gas rectification unit 81, heated by the heater 821 of the gas heating unit 82, and sent to the heating furnace unit 83.

Next, the operation of the reflow apparatus 80 having the above-mentioned structure will be described with reference to FIG.

This reflow device 80 is different from the one for heating the substrate P to be processed by the downflow of hot air used in the above-mentioned conventional reflow device, and differs from the surface to be heated of the substrate P to be heated in hot air. Fa is flown in parallel to perform heating.

First, under the control of the controller 85, the fan 8
11 and the electric heater 821 are operated, the opening / closing valve 842 is closed, and then the opening / closing valve 891 is opened. Then, the fan 811 works to draw in the clean gas from the gas supply source 20, and the gas is the gas supply pipe 89 and the hot air circulation passage pipe 86.
And is supplied to the gas rectifying unit 81 via. The gas is supplied to the gas heating unit 82 and heated by the electric heater 821. The heated gas is sent to the heating furnace section 83 as hot air Fa. The heating temperature of the surface to be heated of the substrate P to be processed is transmitted by the heat of the rectified hot air Fa passing above the surface.

The hot air Fb which has heated the substrate P to be processed in the heating furnace section 83 is changed in direction by the hot air circulation path tube 87, then flows through the hot air circulation path tube 88 and is sent to the exhaust section 84, and the heating furnace section 83. If necessary, part of the hot air Fb is exhausted so that the internal pressure becomes constant, or all of the hot air Fb is exhausted at the end of soldering. When it is not necessary to exhaust the gas, the entire amount of the hot air Fb flows through the hot air circulation passage pipe 86, the gas rectifying unit 81,
The gas is returned to the gas heating unit 82, heated to a predetermined temperature in the above cycle, and circulated at a wind velocity and an air volume that is parallel to the surface to be heated and has a straight traveling property.

The substrate P to be soldered has various sizes of electronic circuit boards, and various parts having different heights, surface areas, surface materials, etc. are mounted on the circuit boards. Since they are placed, their specific heats differ depending on the type of substrate to be processed. Further, it is necessary to change the temperature characteristic of heating depending on the cream solder used. A general temperature profile curve when a general cream solder is used is a curve as shown in FIG. 20, and it is necessary to control the heating temperature on the substrate P to be processed along such a curve. . For the measurement, a thermocouple, which is a temperature detector, an infrared detection element, for example, a thermocouple S is fixed to the plurality of measurement points on the test substrate Pt for the measurement.

Therefore, when the rectifying hot air Fa passing through the heating furnace portion 83 rises to a predetermined temperature and has a sufficient air velocity and air volume, the components are previously prepared in the same manner as the substrate P to be soldered. The test substrate Pt placed on the conveyor 9
1 or put on a tray T and put into a predetermined position in the heating furnace section 83, and the temperature of each portion of the heated test substrate Pt is measured by the thermocouple S, and the test substrate Pt is measured. The gas rectifying unit 81 and the gas heating unit 82 are set so that the temperature becomes the temperature along the temperature profile curve shown in FIG.
The temperature of the hot air Fa supplied from the gas heating unit 82, the wind speed, and the air volume are stored in the microcomputer of the control unit 85 as control factors.

The wind velocity of the hot air in the heating furnace section 83 is, for example,
The control unit 85 controls the rotation speed of the fan 811 so as to be 3 to 7 m / s. When the wind velocity of the hot air Fa is high, a phenomenon occurs such that the component on the substrate to be processed is displaced, collapsed, or moved. The temperature of the hot air Fa is adjusted by adjusting the amount of current supplied to the electric heater 821, and the amount of air is adjusted by controlling the rotational speed of the fan 811 or the opening angle of the open / close valve 842 of the exhaust unit 84. These controls are performed by the control unit 85.
Done under.

Then, the most appropriate temperature profile required for actually heating the surface to be heated of the substrate P to be processed is
As shown in FIG. 20, as described above, various controls such as the rotation speed of the fan 811, the heating temperature of the electric heater 821, and the opening angle of the open / close valve 842 are controlled by the microcomputer in the control unit 85. It is controlled by means of means and at the same time those values are stored in the memory of the microcomputer.

In this way, a temperature profile is created for each of the various substrates P to be soldered with the components,
After testing and storing the data in the storage unit of the microcomputer, the substrate P to be soldered is loaded into the heating furnace unit 83 from the carry-in port 832 by the conveyor 91 and held at a predetermined position on the bottom thereof. To do. Then, according to the temperature profile peculiar to the substrate to be processed P, for example, if the temperature profile is as shown in FIG. 20, first, the temperature of the surface to be heated is raised to 150 to 170 ° C. (preheat). , Keep the temperature constant for 90 seconds or more to activate the cream solder. Next, 230
The temperature is raised to ˜240 ° C. (main heat) and kept for about 30 seconds or more to melt all the solder uniformly.

After that, the substrate P to be processed is carried out from the carrying-out port (not shown) on the opposite side of the carrying-in port 832 of the heating furnace part 83 to the outside of the heating furnace part 83 by a conveyor, and forcedly cooled by a fan etc. The temperature of the processing substrate P is lowered and the solder is solidified. The components thus placed are soldered.

When the substrate P to be processed is carried out from the heating furnace section 83 as described above, the next substrate to be processed P is carried into the heating furnace section 83 by the conveyor 91, and the cream solder is similarly subjected to the temperature profile described above. Repeat heating, melting, and cooling of.

As described above, according to the reflow apparatus 80 of this embodiment, the reheated surface of the substrate P to be processed is
Since the hot air Fa is flown in parallel, the stagnation point a and the wall jet area b unlike the conventional downflow of hot air do not occur. As a result, uniform heat transfer can be performed on the substrate P to be processed, and good heating can be performed.

[0038]

However, since the reflow device 80 of the invention of the prior application mainly uses heat transfer heating with hot air, the heating efficiency is low. It may be difficult to uniformly heat each component because the heat capacities of the respective components mounted on the substrate P to be processed are different or the heat transfer due to convection heating or radiant heating is different. In the reflow device 80 of the invention of the prior application, as shown in FIG. 18, such a problem is caused by fixing the far-infrared heater 92 to the inner surface of the tube above the substrate P to be processed in the heating furnace portion 83 and using it together. As a result, the difference in heat capacity or the difference in heat transfer can be absorbed.

However, recently, the area of the electronic circuit board is widened, and the parts to be mounted are also large in area and volume, and the materials and the thermal conductivity are different. Parts are mixed and mounted on minute parts. For example, since the material of the surface of the electrolytic capacitor is aluminum, heat is reflected on the surface of the component against radiant heating, and heat transfer becomes insensitive. This phenomenon becomes more remarkable as the size of the component increases.

Therefore, the size of the component to be mounted,
When the width of the material and the like becomes large, a large difference in heat capacity or a large difference in heat transfer due to the difference between the materials is generated even if the far infrared heater is used in addition to the heat transfer heating by hot air. The intensity of radiant energy can be controlled, but its distribution cannot be controlled. That is, the partial radiation intensity cannot be controlled, and the substrate to be processed is always given a constant energy distribution. Therefore, 1. If there are a portion having a large heat capacity, a portion having a small heat capacity, a portion that is difficult to be radiantly heated, and a portion that is difficult to be radiantly heated due to the arrangement of components, the temperature rise varies widely among the respective portions of the substrate to be processed. In particular, when waiting for a temperature rise of a large heat capacity component with a slow temperature rise, a small heat capacity component with a fast temperature rise will exceed the heat resistant temperature or will exceed the heat resistant time and will be destroyed. 2. 2. Radiation energy greatly differs between the outer periphery and the center of the substrate to be processed, and the variation in temperature rise between the outer periphery and the center of the substrate to be processed becomes large. If there are parts (groups) with a large heat capacity on the back surface of the substrate to be processed, the hot air on the front and back surfaces of the substrate to be processed and the radiant heating from the surface of the substrate to be processed by the far-infrared heater will not be enough, and the temperature rise in the vicinity There is a problem such as being slow.

Further, in the prior art, the distance between the substrate to be processed and the far infrared heater is fixed, and it takes time to change the temperature of the far infrared heater when controlling the temperature profile. Since it will be cooled by the air flow while it is on, effective profile control cannot be performed.

Further, in the prior invention, as shown in FIG. 19, the upper surface of the conduit of the heating furnace part 83B is an inclined furnace wall 831B inclined from the upstream to the downstream, and the sectional area of the conduit is directed to the downstream. By making it smaller, the heat transfer coefficient of each part on the substrate P to be processed is aimed to be uniform, but as shown in FIG. Since a boundary layer of temperature is generated, it is not sufficient to make the heat transfer coefficient uniform, as shown in FIG.

The present invention is intended to solve such a problem. Even if there is a large difference in heat capacity or a large difference in heat transfer between components to be mounted, heat transfer by hot air and direct transfer by radiant energy. An object of the present invention is to obtain a reflow device which can heat each component uniformly by using heating together and can surely solder.

[0044]

Therefore, according to the first aspect of the present invention, a reflow apparatus is provided with a gas supply source, a gas heating means for heating the gas to a predetermined temperature, and an object on which parts are mounted. When a processed substrate is loaded, the processed substrate heating means capable of holding the processed substrate in a horizontal position at a predetermined position, and the front and back surfaces of the processed substrate held in the processed substrate heating means In parallel with the gas rectifying means for supplying the gas heated to a predetermined temperature by the gas heating means to the target substrate heating means as hot air at a predetermined speed, and arranged above the target substrate, A far infrared heater for heating a substrate to be processed by radiant heat, and a control means for controlling the temperature, speed, flow rate of the hot air and the radiant heat temperature of the far infrared heater, and are configured to solve the above problems. ing.

A lower far infrared heater for heating the back surface of the substrate to be processed by radiant heat may be provided below the substrate to be processed. It is preferable that the far infrared heater is composed of a plurality of independent small far infrared heaters, and the heating temperature of each of the small far infrared heaters is individually controlled by the control means. Further, it is preferable that the far-infrared heater is moved up and down with respect to the substrate to be processed by a vertical movement driving means, and the vertical movement driving means may be constituted by a ball screw mechanism or a link mechanism. . Furthermore, the temperature profile can be controlled by controlling the vertical position of the far infrared heater and / or the velocity of the hot air from the lower far infrared heater and the gas rectifying means by the control means. Furthermore, the far-infrared heater and / or the lower far-infrared heater may be configured to be displaced in the horizontal direction with respect to the substrate to be processed, and furthermore, the substrate to be processed and the far-infrared heater A far infrared shutter that can be inserted between the substrate to be processed and the lower far infrared heater may be provided.

In the second invention, the reflow device is
When a gas supply source, a gas heating unit that heats the gas to a predetermined temperature, and a substrate to be processed on which components are placed are input, the substrate to be processed can be held horizontally at a predetermined position. The target substrate heating means and the gas heated to a predetermined temperature by the gas heating means in parallel to both the front and back surfaces of the target substrate held in the target substrate heating means are heated with a predetermined speed of hot air. A gas rectifying means for supplying the substrate to be processed heating means, a rectifying block arranged on the upstream side of the substrate to be processed, for adjusting the flow of the hot air from the gas rectifying means to hit the substrate to be processed, and The above problem is solved by providing a control means for controlling the temperature, speed and flow rate of the hot air.

Furthermore, in the third invention, the reflow device is provided with a gas supply source, a gas heating means for heating the gas to a predetermined temperature, and a substrate on which parts are placed. A substrate heating means capable of holding the substrate in a horizontal position at a predetermined position, and the gas heating means parallel to both front and back surfaces of the substrate held in the substrate heating means. A gas rectifying means for supplying the gas heated to a predetermined temperature as a hot air at a predetermined speed to the target substrate heating means, and the target substrate disposed above the target substrate and heated by the radiant heat. A plurality of independent small far-infrared heaters, a vertical movement driving means for moving the small far-infrared heaters up and down with respect to the substrate to be processed, and the substrate to be processed arranged below the substrate to be processed. Back of And lower far-infrared heater for heating by radiant heat is disposed on an upstream side of the substrate to be processed,
A rectifying block that adjusts the flow of the hot air from the gas rectifying means that hits the substrate to be processed, and the temperature of the hot air,
Control means for controlling speed, flow rate, vertical positions of the plurality of small far infrared heaters, heating temperature of each small far infrared heater, heating temperature of the lower far infrared heater, temperature profile of the substrate heating means, and the like. The above problem is solved by providing the following.

Therefore, according to the reflow apparatus of the first invention, since the far infrared heater is provided, in addition to the heating by the heat transfer by the hot air parallel to the substrate to be processed, the radiant heat of the far infrared heater is also used. The substrate to be processed can be heated and, if necessary, the lower far infrared heater can be used to further improve the heating efficiency.

In the case of this reflow apparatus, the far infrared heater is composed of a plurality of independent small far infrared heaters, and the heating temperature of each of the small far infrared heaters is individually controlled so that the far infrared heater is mounted on the substrate to be processed. The distribution of the radiant energy received by the substrate to be processed can be arbitrarily controlled according to the heat capacity of the components present, and the variation in temperature on the substrate to be processed can be reduced. Further, by moving the far infrared heater up and down with respect to the substrate to be processed, a rapid change in the radiant energy intensity can be obtained, and efficient temperature profile control can be performed. The up-and-down position of the far-infrared heater can be finely adjusted by using a ball screw mechanism as the driving means for vertical movement, and the height of the reflow device can be suppressed by using a link mechanism. Furthermore, by heating the far infrared heater and / or the lower far infrared heater horizontally with respect to the substrate to be processed, it is possible to selectively block the heating of all or part of the substrate to be processed. Further, according to the second reflow device, by disposing the rectifying block on the upstream side of the substrate to be processed, it is possible to control the parallel hot air from the rectifying means, and to reduce the local heat transfer coefficient on the substrate to be processed. It is possible to make the upstream and downstream of the substrate to be processed uniform, which makes it possible to equalize the rate of temperature rise and reduce variations in the temperature of the substrate to be processed.

According to the third reflow apparatus,
By heating air and heat transfer from the air and direct heating by radiant energy from a plurality of small far-infrared heaters and lower far-infrared heaters, it is possible to effectively and efficiently heat according to the characteristics of the substrate to be processed, By arranging the rectifying block upstream of the substrate to be processed to control the parallel flow of hot air, the local heat transfer coefficient on the substrate can be made more uniform on the upstream side and the downstream side of the substrate, thus increasing the temperature rise. The speed can be made uniform and the temperature variation on the substrate can be reduced.

[0051]

DETAILED DESCRIPTION OF THE INVENTION A reflow apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a conceptual configuration diagram of a reflow apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing an array of upper far infrared heaters in a heating furnace section of the reflow apparatus shown in FIG. 1, and FIG. Is a graph showing a temperature profile on the substrate to be processed when the substrate to be processed of the embodiment is heated by the reflow device of the present invention, and FIG. 4 is a diagram illustrating a substrate to be processed of the embodiment to be heated by the conventional reflow device. 5 is a graph showing the temperature profile on the substrate to be processed in the case, FIG. 5 is a graph of the temperature / velocity boundary layer when a flat plate is placed in the gas heating unit (reflow furnace) of the present invention and hot air is flowed, and FIG. The temperature shown in 5
A graph of local heat transfer coefficient on a flat plate in the velocity boundary layer, FIG. 7 is a graph showing distribution of radiant energy in various heating states with respect to a substrate to be processed, and FIG. 8 is a second graph suitable for use in the present invention.
FIG. 9 is a conceptual diagram of a vertical movement driving device for an upper far infrared heater according to the embodiment, and FIG. 9 is a conceptual diagram of a vertical movement driving device for an upper far infrared heater according to a third preferred embodiment of the present invention.

First, the structure of a reflow apparatus according to an embodiment of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 10 generally indicates the reflow apparatus of the present invention. The reflow device 10 is provided with a gas supply source 1 which is sequentially arranged from upstream to downstream.
1, blower unit 12, gas heating unit 13, gas rectifying unit 14, heating furnace unit 15, substrate support member 153 to be processed of heating furnace unit 15
Baffle block 16 disposed upstream of the heating furnace part 15, and a hot air circulation passage part formed from the exhaust side of the heating furnace part 15 to the lower part of the heating furnace part 15, the gas rectifying part 14, the gas heating part 13, and the air blowing part 12. 17, an exhaust unit 18 provided in a part thereof, a vertical movement drive device 20A for a far infrared heater disposed above the heating furnace unit 15, a control unit 19, and a temperature measurement sensor 30. These blowers 12,
The gas heating unit 13, the gas rectifying unit 14, and the heating furnace unit 15 are tubular bodies, and the tubular bodies have a rectangular structure with the same cross-section.

The gas supply source 11 is connected to the blower unit 12 and is constructed so that clean air or an inert gas such as nitrogen gas can be supplied or shut off at any time by opening and closing an open / close valve (not shown). There is.

A fan (not shown) is incorporated in the blower unit 12, and the gas is sent to the gas heating unit 13 at a predetermined speed by operating the fan. An electric heater (not shown) is built in the gas heating unit 13 to heat the gas to a predetermined temperature. The heated gas is sent from the gas heating unit 13 to the gas rectifying unit 14 by the fan, and the heating furnace unit 15
The temperature and flow velocity in the cross section of the conduit are made uniform according to the substrate P to be processed placed on the substrate P, and the hot air Fa having a direction parallel to the substrate P to be processed is prepared and sent to the heating furnace unit 15. To be

The hot air Fa sent to the heating furnace section 15 is rectified by the rectifying block 16 and is placed on the substrate P to be processed.
The flow is controlled so that the heat transfer coefficient in each part on both the front and back sides is constant.

The heating furnace section 15 includes an upper far infrared heater 15
1, a lower far infrared heater 152, and a supporting member 153 that supports the substrate P to be processed. Support member 15
3 is arranged in the lower tube of the heating furnace unit 15 and is composed of thin pins or the like that support the four corners of the substrate P to be processed so as to support the hot air hitting the front and back surfaces of the substrate P as little as possible. Has been done.

The upper far infrared heater 151 is composed of a plurality of small far infrared heaters as illustrated in FIG. These small far-infrared heaters have, for example, a panel structure having a short side length La of 60 mm and a long side length Lb of 120 mm, and have four sheets in the width direction of the heating furnace section 15, and upstream of the heating furnace section 15. From the side to the downstream side, a total of 24 small far-infrared heaters, 6 in each row, are arranged in a matrix form with adjacent gaps Ga and Gb of 5 mm. For convenience of description, these small far-infrared heaters are denoted by reference numerals 151A, 151B, ... 151X. Hereinafter, these small far infrared heaters will be collectively referred to as "small far infrared heater 151A ...".

Then, the plurality of small far infrared heaters 1
51A ... Face the opening 155 of the upper tube 154 formed above the support member 153, are supported by the vertical movement drive device 20A, and are arranged in one plane. The one lower far-infrared heater 152 is disposed on the inner surface of the bottom side of the tube below the support member 153.

The lower far-infrared heater 152 is also composed of a plurality of, for example, 12 small far-infrared heaters having a panel structure, like the small far-infrared heater 151A of the upper far-infrared heater 151 shown in FIG. It is arranged in a shape.

The individual small far-infrared heaters 151A, ..., Which constitute the upper far-infrared heater 151 and the lower far-infrared heater 152, are controlled as described below so that desired radiation energy can be obtained at both front and back sides of the substrate P to be processed. The temperature is individually adjusted by the unit 19, and the substrate P to be processed is heated by radiant energy corresponding to the temperature.

Depending on the temperature characteristics of the substrate P to be processed, the far-infrared heater does not have to be composed of a plurality of small far-infrared heaters 151A as described above, but one far-infrared heater is used. The substrate P to be processed may be configured to be radiantly heated. However, also in this case, the heating temperature can be adjusted by moving the far infrared heater up and down.

The temperature in the heating furnace section 15 or the temperature of the substrate P to be processed is measured by the temperature measuring sensor 30 and the data is fed back to the control section 19.
Based on these data, the control unit 19 determines the number of rotations of the fan of the blower unit 12, the temperature of the gas heating unit 13, the temperatures of the upper far infrared heater 151 and the lower far infrared heater 152, and the height of the upper far infrared heater 151. A predetermined temperature profile of the target substrate P to be controlled and heated is realized.

The substrate P to be processed is placed on the supporting member 153 with its surface to be heated facing upward, and heated by the combined use of hot air Fa and radiant heat of the upper far infrared heater 151 and / or the lower far infrared heater 152 by the heating method described later. To be done. The substrate P to be processed may be carried in to the support member 153 by a belt conveyor (not shown), or may be configured to be carried in by being placed on a tray (not shown) with its heated surface facing upward.

The used hot air Fb is returned to the air blowing section 12 through the hot air circulation path section 17. When all the soldering work is completed, hot air is exhausted from the exhaust unit 18.

The substrate P carrying-in mechanism, the hot air circulation passage portion 17 and the like are not essential parts of the present invention, so detailed description thereof will be omitted.

The up-and-down drive device 20A is based on a quadrilateral support substrate 21 fixed to an upper tube 154 projecting above the heating furnace section 15 so as to cover the upper surface of the heating furnace section 15. Is assembled. For example, four shafts 22 are provided at four corners of the support substrate 21, and two shafts 22 are provided on each side of the heating furnace section 15 on each side.
A quadrilateral heater support plate 24 is attached to the lower ends of the quadrilateral heater supports 3 to support the small far-infrared heater 151. The area of the heater support plate 24 is, of course, slightly smaller than the area of the support substrate 21, and has such an external dimension that a slight gap is opened between the heater support plate 24 and the inner wall of the upper tube body 154. For example, one ball screw 2 is provided at the center of the support substrate 21 and the heater support plate 24.
5 is attached. The upper end of the ball screw 25 projects above the 25 support substrate 21 via a ball screw nut 26, and the lower end of the ball screw 25 has a heater support plate 24.
It is fixed to. A pulley 27 is fixed to the upper end of the ball screw 25, a motor M is fixed on the support substrate 21 near the pulley 27, and a motor pulley 28 is attached to its rotation shaft.
A belt 29 is provided between the pulley 27 and the motor pulley 28.
The ball screw 25 is rotated by rotating the motor 27, and the heater support plate 24 can be moved up and down. In this case, the heater support plate 24
Is supported by four shafts 22, and the linear bush 23
And is vertically moved in parallel with the surface of the substrate P to be processed placed on the support member 153 of the heating furnace unit 15.
The plurality of small far-infrared heaters 151A ... Are attached to the lower surface of the heater support plate 24. The vertical movement driving device 20A has the above-described mechanism and supports the upper far infrared heater 151, that is, a plurality of small far infrared heaters 151A so as to be vertically movable.

As described above, the reflow apparatus 10 of the present invention is constructed.

Next, the operation of each part in the reflow apparatus 10 will be described. 1. Heating of the substrate to be processed P The heating of the substrate to be processed P is performed by heat transfer heating by the hot air Fa, and the far infrared rays from the plurality of small far infrared ray heaters 151A ... It is heated by radiant heating with radiant energy. 2. Rectification by the rectification block 18 Generally, when there is a flat plate Pa parallel to the flow in the flow,
As shown in FIG. 21, a temperature / velocity boundary layer is generated from the upstream end of the flat plate Pa. A laminar boundary layer is formed at a flow velocity in a range where there is no displacement or collapse of the components on the flat plate Pa. At this time, the local heat transfer coefficient on the flat plate Pa is as shown in FIG.
There is a big difference between upstream and downstream of. Therefore, the rate of temperature rise is also greatly different, and the variation in temperature on the flat plate Pa becomes large.

On the other hand, when the rectifying block 16 is placed upstream of the flat plate Pa to control the flow as in the present invention, as shown in FIG.
It is possible to create a velocity / temperature boundary layer such as. In this case, the local heat transfer coefficient on the flat plate Pa is as shown in FIG. 6, and the upstream and downstream of the flat plate Pa do not differ greatly. Therefore, the rate of temperature rise does not change significantly, and the variation in temperature on the flat plate Pa is reduced. 3. Radiant energy distribution control (main) A plurality of small far-infrared heaters 151 can independently set the temperature. When the temperatures of the small far infrared heaters 151A ...
As shown in (4), the radiant energy distribution received by each part of the substrate P to be processed varies widely. However, by appropriately setting the temperature of each small far-infrared heater 151, as shown in FIG. 7B, the distribution of the radiant energy received by each part of the substrate P to be processed is made uniform, or as shown in FIG. 7C. In addition, it is possible to control the radiant energy distribution such that it is strong in necessary parts and weak in unnecessary parts. 4. Radiant Energy Distribution Control (Sub) The temperature of each small far-infrared heater that constitutes the lower far-infrared heater 152 can be independently set. By appropriately setting the temperature of each small far infrared heater, the radiant energy is concentrated in a portion where the temperature of the substrate P is difficult to rise (such as a portion where a large amount of heat capacity is gathered), and a plurality of small far infrared rays Heater 15
The function of assisting the heating by 1A ... And reducing the variation in the temperature of the entire substrate P to be processed is performed. 5. In the part where a fast temperature rise is required on the vertical drive control temperature profile of the plurality of small far-infrared heaters 151A ...
It is necessary to increase the intensity of the radiant energy and suppress the radiant energy intensity in the part where a slow temperature rise (preheat, main reflow) is required.

For this purpose, a plurality of small far infrared heaters 15 are used.
1A ... Are simultaneously driven up and down, and when the intensity of the radiant energy is desired to be increased, they are brought closer to the substrate P to be processed, and when the intensity of the radiant energy is desired to be suppressed, they are moved away from the substrate P to be processed. 6. The temperature profile control controller 19 is based on the measured temperature in the furnace of the gas heating unit 13 and the temperature data of the substrate P to be processed, the rotation speed of the fan of the blower unit 12, the temperature of the gas heating unit 13, and the plurality of temperatures. The temperature of each of the small far-infrared heaters 151A ... and the small far-infrared heaters 152 of the lower far-infrared heater 152, and the heights of the plurality of small far-infrared heaters 151A. Achieve optimum predetermined temperature profile. The heating temperature of the target substrate P to be controlled is sensitive to the controllable parameters, in particular, the number of rotations of the fan of the blower unit 12 and the heights of the plurality of small far-infrared heaters 151A. Therefore, the heating of the substrate P to be processed by the heating furnace unit 15 controls the temperature profile mainly by these two parameters.

Next, an embodiment of the heating furnace section 15 in the reflow apparatus 10 of the present invention will be shown below.

Height of flow path of heating furnace part 15: 80 mm Width of flow path of heating furnace part 15: 510 mm Height of rectifying block 16: 70 mm Length of rectifying block 16: 100 mm Width of rectifying block 16: 510 mm ( Full width of flow path) Length of substrate to be processed P: 160 mm Width of substrate to be processed P: 243 mm Thickness of substrate to be processed P: 1 mm Height from bottom of flow path of substrate to be processed P: 45 mm Rectification with substrate to be processed P Distance from the block 16: 45 mm Distance between the substrate P to be processed and the upper far infrared heater 151: 35 mm (when profile heating) to 250 mm (when profile horizontal) On such a supporting member 153 in the heating furnace section 15 The target substrate P shown in FIG. 2 is placed on the upper far infrared heater 15
The temperature of the small far-infrared heater 151A ... and the lower far-infrared heater 152, and the temperature and speed of the hot air Fa, which are 1, are set under the following conditions and heated. The processed substrate P includes various parts, for example, parts having a small heat capacity such as a chip resistor and a CPU (Central Processing).
Units having a large heat capacity such as Unit) are mixedly mounted. In FIG. 2, reference numeral A is a CPU and reference numeral B is a chip resistor.

Temperature distribution of the small far infrared heaters 151A ... (according to the arrangement of the small far infrared heaters 151A, 151B ... Shown in FIG. 2): 480 ° C., 500 ° C., 580 ° C., 560 ° C., 580 550 ° C 210 ° C, 245 ° C, 730 ° C, 660 ° C, 550 ° C, 530 ° C 220 ° C, 360 ° C, 400 ° C, 500 ° C, 550 ° C, 550 ° C 600 ° C, 600 ° C, 550 ° C, 500 ° C, 500 ° C, 500 ° C Temperature of lower far infrared heater 152: 350 ° C (no temperature distribution) Temperature of hot air Fa: 150 ° C Air velocity of hot air Fa: 1 m / s (when profile is heated) to 4 m / s (when profile is horizontal) The heating temperature profile of each component part on the substrate P to be processed under such conditions is as shown in FIG. The solid line is the part A part in FIG. 2, and the dotted line is the part B part. As described above, the component A is mainly heated by radiation from the small far infrared heater 151I (temperature 730 ° C.), and the component B is mainly heated by the small far infrared heater 15I.
Heated by radiation from 1 N (temperature 360 ° C.).

As is apparent from FIG. 3, the temperature variation ΔT at the point where the component A is present on the substrate P to be processed and the point where the component B is present is such that there is a large difference in the heat capacities of the components at the temperature measuring portion. Nevertheless, it was kept at about 5.5 ° C. Incidentally, the heating temperature profile of each part on the substrate P to be processed when the same substrate P to be processed is put into the reflow apparatus 50 of the prior art shown in FIG. 10 and heated is shown in FIG. Like As shown in FIG. 4, there is a part A on the substrate P to be processed,
The temperature variation ΔT at the point where the component B exists is 20 ° C. to 2
There was a large variation of 5 ° C.

A plurality of small far infrared heaters 151A ...
By applying a link mechanism to the drive mechanism in the vertical direction, the space in the height direction due to the ball screw mechanism can be suppressed. 8 and 9 show two types of vertical motion drive devices using a link mechanism. The same components as those of the up-and-down drive unit 20A will be described with the same reference numerals.

First, referring to FIG. 8, a vertical movement drive unit 20B of the second embodiment using a link mechanism will be described.

As shown in FIG. 1, the vertical drive unit 20B is also fixed to the upper tube body 154 formed so as to project above the heating furnace section 15 so as to cover the upper surface of the heating furnace section 15. It is assembled on the basis of a quadrilateral supporting substrate 21. For example, a pair of guide rails 31 extending from the right end portion of the lower surface of the support substrate 21 to the front side and the other side in the drawing and the central portion thereof.
Is fixed. A movable connecting member 32 is slidably attached to each of the guide rails 31. A pair of links 33 are rotatably connected to the movable connecting members 32, and the other ends of the links 33 are connected to a pair of connectors 34 fixed to the left and right ends of the upper surface of the heater support plate 24. Each is rotatably attached.

Further, in the figure, a pair of connectors 35 are fixed also on the front side and the other side of the left end of the lower surface of the support substrate 21, and face the guide rails 31 from the central portion of the upper surface of the heater support plate 24. A pair of guide rails 36 are fixed to the front end and the other side of the guide rail 36, and a movable connecting member 37 is slidably attached to each of the guide rails 36. One end of a pair of links 38 is rotatably connected to the connector 35, and the other ends thereof are rotatably connected to the movable connecting member 39. That is, the links 38 intersect the links 34 and are connected by the connecting shaft 39 at the intersections.

A ball screw 40 is attached to the front side and the other side of the upper surface of the support substrate 21 so as to extend from substantially the center to the right end of the support substrate 21. One end of the ball screw 40 is pivotally supported by a bearing 41 fixed to the front side and the other side of the right end of the upper surface of the support substrate 21,
The other end is connected and supported via a coupling 43 to a rotation shaft 42 of a motor M fixed to the left of the center of the upper surface of the support substrate 21. A pair of ball screw nuts 44 are attached to the left end side of each ball screw 40. The pair of movable connecting members 32 are connected to the lower ends of the pair of ball screw nuts 44.

A plurality of small far infrared heaters 151 having a panel structure are fixed to the lower surface of the heater support plate 24.

The vertical movement drive unit 20B having the above-described structure
Causes the ball screw 40 to rotate by rotating the motor M, and the ball screw nut 44
, And the movable connecting member 32 slides on the guide rail 31 and moves to the right end of the ball screw 40. According to this movement, at the same time, the link 33 pulls up the connector 34, and according to the movement, the link 38 is pulled up with the connector 35 as a fulcrum, and the movable connecting member 3 at the other end of the link 38 is pulled up.
7 slides on the guide rail 36 and moves to the right end thereof. Therefore, the heater support plate 24 and the small far-infrared heater 151 connected to the links 33 and 38 are pulled up to the position shown by the chain double-dashed line. The height position of the small far-infrared heater 151 can be adjusted to an arbitrary position by controlling the motor M by the control unit 19.

When the small far-infrared heater 151 is lowered, the rotation of the motor M is reversed to move the links 33, 38 and the like in the direction opposite to the above movement, and the heater is moved to the lowest position. The support plate 24 and the small far infrared heater 151 can be lowered. In this way, the small far infrared heater 151 can be moved up and down as shown by the arrow.

Next, referring to FIG. 9, a vertical movement drive device 20 of a third embodiment suitable for use in the reflow device 10 of the present invention.
The schematic mechanism of C will be described.

In the vertical drive unit 20C, two pairs of left and right link mechanisms 45A and 45B in which a plurality of links are formed in a so-called pantograph structure are mounted on a support plate 46 fixed to the upper surface of the heater support plate 24. It is movably attached, and the other end of each is connected to large gears 47A and 47B. Of these large gears 47A and 47B, one large gear 47A is fixed to a rotating shaft of a motor (not shown). The small gear 48B meshes with the small gear 48A, and the other large gear 47B meshes with the small gear 48A.
Is meshing with. The intermediate portions of the link mechanisms 45A and 45B are connected by a connecting rod 49.

A vertical movement drive unit 20C having the above-described structure.
Rotates the motor clockwise to rotate the small gear 48A clockwise, and this rotation causes the small gear 48B to rotate counterclockwise, and the large gear 47A meshing with these rotates counterclockwise. The large gear 47B rotates clockwise and pulls up the respective link mechanisms 45A, 45B. Therefore, according to this movement, the heater support plate 24 and the small far infrared heater 151 are also pulled up to the upper position shown by the chain double-dashed line.

When the small far infrared heater 151 is lowered, the link mechanism 45A, 45B can be extended downward by reversing the rotation of the motor.
The heater support plate 24 and the small far infrared heater 151 can be lowered to the lowest position. In this way, the small far infrared heater 151 can be moved up and down as shown by the arrow.

In the vertical movement drive device of each of the above embodiments,
Although the small far-infrared heater 151 is moved up and down, the lower far-infrared heater 152 may be moved up and down with respect to the back surface of the target substrate P according to the characteristics of the target substrate P. With such a configuration in which it is moved up and down, the intensity of the radiant energy can be further changed, and the controllability of the temperature profile can be further enhanced. If the radiant energy from the surface of the substrate P to be processed is sufficient, even if the lower far infrared heater 152 is removed,
The temperature of the substrate P to be processed can be controlled.

As described above, the intensity of the radiant energy can be changed by moving the small far-infrared heater 151 and the lower far-infrared heater 152 close to or away from the substrate P to be processed vertically. Even if it is shifted in the horizontal direction with respect to the processing substrate P, the heating intensity can be changed. However, in this case, heating by radiant energy is on / off control, and the intensity cannot be continuously changed.

Further, instead of changing the heating temperature by changing the distance between the small far infrared heater 151 or the lower far infrared heater 152 and the substrate to be processed P, a shutter for blocking far infrared rays is provided between the substrate to be processed P. There is also a method of inserting and changing the heating temperature. Also in this case, the heating by the radiant energy is on / off control, and the intensity cannot be continuously changed.

[0092]

As described above, according to the present invention, 1. Direct heating of the substrate to be processed by radiant energy from the small far infrared heater and / or lower far infrared heater can heat the gas and heat it more efficiently than heating by heat transfer from the gas, thus saving energy. Can be realized 2. By controlling the flow of hot air by placing a rectifying block upstream of the substrate to be processed, the local heat transfer coefficient on the substrate to be processed can be made uniform on the upstream side and the downstream side of the substrate to be processed, thus increasing the rate of temperature rise. It is possible to reduce the variation of temperature on the substrate to be processed. By partially controlling the temperature of the far-infrared heater placed in parallel with the substrate to be processed with a plurality of small far-infrared heaters, the distribution of radiant energy received by the substrate to be processed can be arbitrarily controlled, and the temperature on the substrate to be processed can be controlled. Variations can be reduced 4. By the radiant energy from the back surface of the substrate to be processed,
By supplementarily heating a portion of the substrate to be processed having a large heat capacity, it is possible to reduce variations in temperature on the substrate to be processed. By changing the distance between the far-infrared heater and the substrate, the heating intensity can be rapidly changed by the radiant energy, and an efficient temperature profile can be controlled.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram of a reflow device according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of upper far infrared heaters in a heating furnace section of the reflow device shown in FIG.

FIG. 3 is a graph showing a temperature profile on a substrate to be processed when the substrate to be processed in one example is heated by the reflow apparatus of the present invention.

FIG. 4 is a graph showing a temperature profile on a target substrate when the target substrate of one example is heated by a conventional reflow apparatus.

FIG. 5 is a graph of a temperature / velocity boundary layer when a flat plate is placed in the gas heating unit (reflow furnace) of the present invention and hot air is blown.

6 is a graph of a local heat transfer coefficient on a flat plate in the temperature / velocity boundary layer shown in FIG.

FIG. 7 is a graph showing a distribution of radiant energy in various heating states with respect to a substrate to be processed.

FIG. 8 is a conceptual diagram of a vertical drive device for a small far infrared heater according to a second preferred embodiment of the present invention.

FIG. 9 is a conceptual diagram of a vertical movement driving device for a small far infrared heater according to a third preferred embodiment of the present invention.

FIG. 10 is a conceptual configuration diagram of a reflow device according to a first embodiment of the prior art.

11 is a schematic diagram showing a flow of hot air blown from the reflow device shown in FIG.

FIG. 12 is a temperature profile when a substrate to be processed is heated by a conventional reflow apparatus.

FIG. 13 is a conceptual configuration diagram of a second embodiment of a reflow device of the related art.

FIG. 14 is an explanatory view showing a convection state of hot air in the reflow device shown in FIG.

FIG. 15 is a perspective view of a reflow device according to an embodiment of the prior invention.

16 is a cross-sectional side view of the reflow device shown in FIG. 15 taken along the line AA.

FIG. 17 is an enlarged cross-sectional view of a portion indicated by arrow A of the reflow device shown in FIG.

FIG. 18 is a partially enlarged cross-sectional view of a modified example of the heating furnace section in the pre-reflow device shown in FIG.

FIG. 19 is a partially enlarged cross-sectional view of another modification of the heating furnace section in the reflow device shown in FIG.

FIG. 20 is a curve showing a general temperature profile that can be used in the soldering method of the prior invention.

FIG. 21 is a graph of a temperature / velocity boundary layer when a flat plate is placed on a gas heating unit (reflow furnace) of the related art and hot air is flowed.

22 is a graph of a local heat transfer coefficient on a flat plate in the temperature / velocity boundary layer shown in FIG.

[Explanation of symbols]

10 ... Reflow device of one embodiment of the present invention, 12 ... Blower part, 13 ... Gas heating part, 14 ... Gas rectifying part, 15 ... Heating furnace part, 151 ... Outer far infrared heater, 151A ...
Small far infrared heater, 152 ... Lower far infrared heater, 1
53 ... Support member, 16 ... Straightening block, 17 ... Hot air circulation passage section, 18 ... Exhaust section, 19 ... Control section, 20A ... Vertical movement drive apparatus of the first embodiment, 20B ... Vertical movement drive apparatus of the second embodiment , 20C ... Vertical movement driving device of the third embodiment, 2
1 ... Support substrate, 22 ... Shaft, 24 ... Heater support plate,
25, 40 ... Ball screw, 30 ... Temperature measuring sensor, 3
1, 36 ... Guide rails, 33, 38 ... Links, 45
A, 45B ... Link mechanism, 47A, 47B ... Large gear, 4
8A, 48B ... small gear, Fa ... hot air, P ... substrate to be processed

Continued front page    (72) Inventor Toshihiko Sugano             Sony 6-735 Kitashinagawa, Shinagawa-ku, Tokyo             Within the corporation F term (reference) 5E319 AC01 BB05 CC33 CC45 CC49                       CD35 GG03

Claims (11)

[Claims] 1. A gas supply source, a gas heating means for heating the gas to a predetermined temperature, and a substrate to be processed at a predetermined position when a substrate to be processed on which components are placed is loaded. The target substrate heating means that can be held in a horizontal state, and the gas heated to a predetermined temperature by the gas heating means in parallel to both the front and back surfaces of the target substrate that is held in the target substrate heating means. A gas rectifying unit that supplies the target substrate heating unit as hot air at a predetermined speed, a far-infrared heater that is disposed above the target substrate and heats the target substrate by radiant heat, and the hot air A reflow device comprising: a control unit for controlling the temperature, the speed, the flow rate, and the temperature of the radiant heat of the far-infrared heater. 2. The reflow apparatus according to claim 1, further comprising a lower far-infrared heater which is disposed below the substrate to be processed and which heats the back surface of the substrate to be processed by radiant heat. . 3. The far infrared heater is composed of a plurality of independent small far infrared heaters, and the heating temperature of the small far infrared heater is individually controlled by the control means. The reflow device described in. 4. The reflow apparatus according to claim 1, wherein the far-infrared heater is supported by an up-and-down movement driving unit that can move up and down with respect to the substrate to be processed. 5. The reflow apparatus according to claim 4, wherein the up-and-down movement driving means is composed of a ball screw mechanism. 6. The reflow apparatus according to claim 4, wherein the up-and-down drive means is composed of a link mechanism. 7. The temperature profile is controlled by controlling the vertical position of the far infrared heater and / or the velocity of the hot air from the lower far infrared heater and the gas rectifying means by the control means. The reflow apparatus according to any one of claims 2 to 6. 8. The far-infrared heater and / or the lower far-infrared heater is supported by a supporting means that can be horizontally displaced with respect to the substrate to be processed. The reflow device described in. 9. A far-infrared shutter that can be inserted between the substrate to be processed and the far-infrared heater and / or between the substrate to be processed and the lower far-infrared heater and that blocks far-infrared rays. 7. The reflow device according to claim 1, wherein 10. A gas supply source, a gas heating means for heating the gas to a predetermined temperature, and a substrate to be processed at a predetermined position when a substrate to be processed on which components are placed is loaded. The target substrate heating means that can be held in a horizontal state, and the gas heated to a predetermined temperature by the gas heating means in parallel to both the front and back surfaces of the target substrate that is held in the target substrate heating means. A gas rectifying unit that supplies hot air of a predetermined speed to the substrate to be processed, and a flow of the hot air from the gas rectifying unit that is arranged upstream of the substrate to be processed and hits the substrate to be processed. A reflow apparatus comprising: a rectification block; and control means for controlling the temperature, speed and flow rate of the hot air. 11. A gas supply source, a gas heating means for heating the gas to a predetermined temperature, and a substrate to be processed at a predetermined position when a substrate to be processed on which components are placed is loaded. The target substrate heating means that can be held in a horizontal state, and the gas heated to a predetermined temperature by the gas heating means in parallel to both the front and back surfaces of the target substrate that is held in the target substrate heating means. A gas rectifying unit that supplies hot air of a predetermined speed to the target substrate heating unit, and a plurality of independent small far-infrared heaters that are disposed above the target substrate and that heat the target substrate by radiant heat. A vertical movement driving means for moving the small far infrared heater up and down with respect to the substrate to be processed; Infrared heater A rectifying block which is arranged on the upstream side of the substrate to be processed and which regulates the flow of the hot air from the gas rectifying means that hits the substrate to be processed; Control means for controlling the vertical position of the infrared heater, the heating temperature of each of the small far infrared heaters, the heating temperature of the lower far infrared heater, the temperature profile of the substrate heating means, and the like. Reflow equipment.