JP4003204B2 - Heat treatment apparatus and heat treatment method for heat treating a plate-like object - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat treatment apparatus and method for heating and cooling a plate-like object to be processed such as a glass substrate, a semiconductor substrate, and a printed board, and an insulating, conductive, or mask forming film formed thereon.
[0002]
[Prior art]
As a conventional heat treatment apparatus, a plurality of heat treatment zones are provided as in a continuous furnace, for example, in a stepwise manner with respect to the object to be processed until the object is unloaded from the first heat treatment zone through the final heat treatment zone. There are those that cause a significant temperature change (hereinafter simply referred to as heat treatment). The stepwise temperature change includes a combination of heating and cooling in addition to pre-heating and multi-step heating such as main heating.
[0003]
[Problems to be solved by the invention]
In the above-described conventional heat treatment apparatus, vibration during conveyance of the workpiece is inevitable. For this reason, for example, when the film is baked on the substrate as the object to be processed by the heat treatment apparatus, the baked film thickness is not uniform, or the bump shape is distorted or uneven when the solder bump is formed. The problem arises.
[0004]
In addition, there is a problem of heat loss from the transfer device provided in the heat treatment apparatus and the opening at both ends, and a problem of enlargement of the heat treatment apparatus. Some objects to be processed have shapes that are not suitable for conveyance.
[0005]
An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a heat treatment apparatus in which an object to be processed is not carried out during heat treatment, and thus the object to be processed does not vibrate. It is another object of the present invention to provide a heat treatment apparatus that has a small heat loss and is small and that can perform heat treatment with high accuracy regardless of the shape of the workpiece.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a heat treatment apparatus of the present invention includes a heat treatment plate to be processed on which a plate-like workpiece is placed, and a radiant heating device that radiates and heats the workpiece on the heat treatment plate, a plurality of flow paths provided inside the thermal processing plate, by and radiation apparatus flow by switching the heat media of different temperatures in different flow path, stepwise temperature change treatment object placed on the heat processing plate In this case, the heat treatment is performed.
[0007]
According to this heat treatment apparatus, since the heat treatment can be performed without transporting the object to be treated, the object to be treated does not vibrate during the heat treatment. In addition, since heat treatment is not performed while the object to be processed is being conveyed, a space for conveying the object to be processed is not required, the apparatus is downsized, and heat loss is reduced. In addition, a workpiece having a shape that is not suitable for transport can be heat-treated with high accuracy.
[0008]
In addition, the heat treatment method of the present invention performed using the above-described apparatus is the first heat that flows in the flow path with respect to the object to be processed placed on the heat treatment plate with the plurality of flow paths formed therein. a step for temperature change an object to be processed by the medium, and process for changes in temperature an object to be processed by the radiant heating system, furthermore, the flowing the second heating medium in different temperature and the first heat medium to the different flow paths A process for changing the temperature of the processed object is provided, and at least one of the heat mediums has a temperature for heating the object to be processed.
[0009]
According to this heat treatment method, it is possible to perform heat treatment with multi-stage temperature changes without conveying the workpiece. The order of the strokes is not limited as described above. For example, the heating by the radiant heating device may be performed first or last.
[0010]
At least one of the temperature changes caused by the heat medium may be cooling.
[0011]
In this case, since the workpiece can be cooled from below and cooled, it is not necessary to blow cold air on the bumps, the bump shape is not distorted or uneven, and the workpiece is directed upward from the workpiece side. As the solder hardens, the generation of defects such as voids can be eliminated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
The heat treatment apparatus of the first embodiment shown in FIG. 1 includes a processing chamber (1) formed by a wall made of heat insulating material, and a plurality of heat insulations arranged at intervals in the processing chamber (1). A material horizontal member (2), a workpiece heat treatment plate (4) disposed on the horizontal member (2) excluding the upper wall of the treatment chamber (1), and an upper surface of each heat treatment plate (4) In addition, a substrate (object to be processed) (P), which is an object to be processed, is disposed on the object to be processed heat treatment plate (4).
[0014]
A plurality of workpiece loading / unloading ports (1a) are formed on the front wall of the processing chamber (1) at intervals in the vertical direction, and a door (5) for opening and closing each loading / unloading port (1a) is provided. . Furthermore, an atmosphere gas supply pipe (6) and an atmosphere gas discharge pipe (7) penetrating the rear wall of the processing chamber (1) are provided, and an atmosphere gas can be introduced into the heat treatment chamber as necessary. In addition, the atmospheric gas can be discharged from the processing chamber. Although not shown, a known workpiece loading / unloading device is disposed in front of the heat treatment apparatus, and the workpiece (P) is loaded / unloaded by the loading / unloading device.
[0015]
FIG. 2 shows details of the heat treatment plate (4). The heat treatment plate (4) is hollow, the heat medium introduction pipe (8) and the heat medium outlet pipe (9) are connected to each other, and the hollow part (4a) serves as a first heat medium flow path. The heat medium introduction pipe (8) and the heat medium lead-out pipe (9) are connected to a first heat medium storage tank (not shown) via valves (B1) and (B2), respectively, and a hollow portion (4a ) Is collected and reused.
[0016]
Further, in the hollow portion (4a), a pipe (10) extending in a meandering manner as viewed from above is disposed, and this pipe (10) serves as a second flow path. Each end of the pipe (10) penetrates the rear wall of the heat treatment plate (4) and protrudes to the outside. The pipe (10) is also connected to a second heat medium storage tank (not shown) via valves (B3) and (B4) so that the heat medium flowing through the pipe (10) is recovered and reused as described later. It has become.
[0017]
In addition, although illustration was abbreviate | omitted, the piping part which connects each heat-medium storage tank and the heat processing board (4) is covered with the heat insulating material.
[0018]
Although the detailed illustration of the radiant heating device (3) is omitted, the radiant heating device (3) includes a main body such as a lamp or a heater that radiates infrared rays or far infrared rays, and a cooling medium flow path (3a passing through the housing of the main body). ). The flow path (3a) is connected to a cooling medium storage tank (not shown) via valves (B9) and (B10).
[0019]
The case where this heat treatment apparatus is used as, for example, a solder reflow apparatus will be described below, but other heat treatments can be performed by this heat treatment apparatus.
[0020]
Since the procedure for placing the workpiece (P) on which the ball-shaped solder (B) is placed on the heat treatment plate (4) and taking it out after the heat treatment is known, the heat treatment plate (4) A procedure for performing a heat treatment on the workpiece (P) placed thereon will be described.
[0021]
First, the valves (B1) and (B2) are opened from the state where the valves (B1), (B2), (B3) and (B4) are closed, so that the first heat medium having a predetermined temperature flows through the hollow portion (4a). The heat medium flowing through the hollow portion (4a) returns to the first heat medium storage tank. Thus, the heat medium circulates between the first heat medium storage tank and the heat treatment plate (4), and the heat medium whose temperature has been lowered is returned to the predetermined temperature again in the storage tank. Heat is not wasted. In this way, the workpiece (P) on the heat treatment plate (4) is preheated to a predetermined temperature. Note that the first heat medium may flow after the object to be processed (P) is placed on the heat treatment plate (4), or on the heat treatment plate (4) on which the first heat medium is flowing. A processed product (P) may be placed.
[0022]
Thereafter, the valve (B1) is closed, and radiation heating is performed from the upper surface side of the substrate (P) by the radiant heating device (3), the temperature is further changed and main heating is performed, and the ball-shaped solder (B) is reflowed.
[0023]
Next, the heating by the radiant heating device (3) is stopped, the valves (B3) and (B4) are opened, and the inside of the pipe (10) is heated by a predetermined temperature (a temperature different from the first heat medium and the radiant heating device (3)). The workpiece (P) is cooled in such a manner that the second heat medium having a temperature lower than the temperature of the substrate (P) thus formed flows. Similarly to the above case, the second heat medium circulates between the second storage tank and the heat treatment plate (4). In this way, the workpiece (P) is cooled to a predetermined temperature by heat transfer through the first heat medium filled in the hollow portion (4a). At the same time, the valves (B9) and (B10) are opened, the cooling medium flows through the cooling medium flow path (3a), and the radiant heating device (3) is cooled.
[0024]
By cooling the radiant heating device (3), the workpiece (P) can be cooled more quickly. Furthermore, since the initial conditions for the next process can be made constant, the reproducibility of the process can be improved, and a uniform process can be performed with a high throughput.
[0025]
What is necessary is just to select suitably the heat medium sent through a hollow part (4a) and piping (10) with use temperature. For example, water is preferable if the operating temperature is 10 to 80 ° C., methanol is preferable if the operating temperature is up to 130 ° C., silicon oil or fluorocarbon is preferable if the operating temperature is 50 to 230 ° C., and naphthalene is preferable if the operating temperature is 200 to 350 ° C.
[0026]
What is necessary is just to select a heating time and temperature fall time suitably.
[0027]
The heat treatment plate (4) and the pipe (10) preferably have good thermal conductivity. Specifically, aluminum or copper is preferable.
[0028]
Next, a heat treatment apparatus according to another embodiment of the present invention will be described with reference to FIG. The heat treatment apparatus described below has the same configuration as that of the heat treatment apparatus described above except for the illustrated portions, and the description thereof will be omitted.
[0029]
FIG. 3 shows an enlarged cross-sectional view of the heat treatment plate portion. In this hollow heat treatment plate (11), a horizontal plate-like partition member (12) is arranged so as to be movable in a direction perpendicular thereto, that is, in an up-and-down direction, and the heat treatment plate (11) is arranged by this horizontal plate-like partition member (12). The interior is divided up and down. FIG. 3 shows a state in which equal amounts of the first and second heat media are contained in the heat treatment plate (11). The horizontal plate-like partition member (12) is positioned at the heat treatment plate (11). It changes with the quantity of the 1st, 2nd heat carrier of the inside. The first heat medium introduction pipe (16) and the first heat medium outlet pipe (15) are connected to the lowermost part of the heat treatment plate (11). In addition, a second heat medium introduction pipe (13) and a second heat medium outlet pipe (14) are connected to the top. Each pipe (13) (14) (15) (16) is provided with a valve (B5) (B6) (B7) (B8).
[0030]
In this heat treatment plate (11), the valves (B5) and (B8) are closed, and the valves (B8) are opened from the state in which the valves (B6) and (B7) are opened, and the first heat medium introduction pipe (16) is opened. The first heat medium having a predetermined temperature flows into the heat treatment plate (11). Then, the first heat medium flows out from the first heat medium outlet pipe (15) to the outside of the heat treatment plate (11). At this time, since the horizontal plate-like partition member (12) is movable up and down, it is pushed up by the pressure of the first heat medium flowing into the heat treatment plate (11), and the heat treatment plate (11) is in the first position. Filled with heat medium. In this way, the object to be processed (P) on the heat treatment plate (11) is heated to a predetermined temperature and preheated.
[0031]
Thereafter, the valve (B8) is closed, and radiant heating is performed from the upper surface side of the substrate (P) by the radiant heating device (3), and the temperature is further changed to perform main heating.
[0032]
And after the to-be-processed object (P) on a heat processing board (11) was made into predetermined temperature, radiation heating is stopped and a valve | bulb (B5) is opened simultaneously. Then, a second heat medium having a predetermined temperature (different from the temperature of the first heat medium) flows into the heat treatment plate (11). At this time, since the valve (B8) is already closed and no pressure is applied to the first heat medium in the heat treatment plate (11), the horizontal plate-like partition is formed as the second heat medium flows into the heat treatment plate (11). The member (12) moves downward, and the first heat medium in the heat treatment plate (11) is pushed out of the heat treatment plate (11). The horizontal plate-like partition member (12) is located at the lowest position in the heat treatment plate (11), and the heat treatment plate (11) is filled with the second heat medium. In this way, the workpiece (P) is lowered to a predetermined temperature. At the same time, the valves (B9) and (B10) are opened so that the cooling medium flows in the cooling medium flow path (3a) and the radiant heating device (3) is cooled, as in the above embodiment.
[0033]
Next, a heat treatment apparatus according to still another embodiment of the present invention will be described with reference to FIG. In the heat treatment plate (20), a film-like partition member (21) is provided instead of the horizontal plate-like partition member (12). The membrane-like partition member (21) has elasticity, and as shown by a solid line in FIG. 4, the peripheral end is fixed to the center of the inner surface of the peripheral wall of the heat treatment plate (20), and the heat treatment plate (20) is fixed. It is divided vertically. The state of the membrane partition member (21) varies depending on the amounts of the first and second heat media in the heat treatment plate (20).
[0034]
In this heat treatment plate (20), when the valves (B5) and (B8) are closed and the valves (B6) and (B7) are opened, the valve (B8) is opened, and the first heat medium introduction pipe (16) opens the first. The heat medium flows into the heat treatment plate (20), and the film-like partition member (21) swells upward as shown by a two-dot chain line in FIG. The membrane partition member (21) has a shape along the upper half of the inner surface of the peripheral wall and the inner surface of the upper wall, and the heat treatment plate (20) is filled with the first heat medium. Thereafter, the valve (B8) is closed, and the substrate (P) is radiantly heated by the radiant heating device (3).
[0035]
Next, stop radiant heating and open the valve (B5) at the same time. Then, the second heat medium flows into the heat treatment plate (20). At this time, since the valve (B8) has already been closed and no pressure is applied to the first heat medium in the heat treatment plate (20), the first heat medium flows as the second heat medium flows into the heat treatment plate (20). Is pushed out of the heat treatment plate (20), and the membrane partition member (21) swells downward. The membrane partition member (21) has a shape along the lower half of the inner surface of the peripheral wall and the inner surface of the lower wall, and the heat treatment plate (20) is filled with the second heat medium. At the same time, the valves (B9) and (B10) are opened so that the cooling medium flows in the cooling medium flow path (3a) and the radiant heating device (3) is cooled, as in the above embodiment.
[0036]
In addition, the heat processing apparatus of this invention is not limited to the structure of the said embodiment, It can change suitably. For example, the opening / closing timing of each valve and the on / off timing of the radiant heating device are not necessarily limited as described above, and an optimal combination of timings may be selected sequentially according to the purpose. The pipe (10) may have a spiral shape when viewed from the plane.
[0037]
In addition, you may replace the flow path of a 1st and 2nd heat carrier. Further, after heating, the temperature can be lowered in two stages. Therefore, the apparatus of the present invention can heat the object to be processed in stages by appropriately selecting the temperatures of the first heat medium and the second heat medium, and can perform heat treatment combining heating and cooling. That is, not only the temperature is lowered after the two-stage heating as described above, but also the three-stage heating can be performed. Furthermore, the radiation heating device can be used not only for solder reflow but also for heat treatment of various substrates and various films formed on the substrate surface.
[0038]
Moreover, the flow path in a heat processing board should just be two or more, and is not limited to a thing with two flow paths like the said embodiment . Na us, the heat treatment carried out by the heating plate are those defined by the temperature of the heat medium can be carried out heating, any of cooling.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a heat treatment apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a heat treatment plate portion of the heat treatment apparatus.
FIG. 3 is an enlarged cross-sectional view of a heat treatment plate portion in a heat treatment apparatus according to another embodiment.
FIG. 4 is an enlarged cross-sectional view of a heat treatment plate portion in a heat treatment apparatus according to another embodiment.
[Explanation of symbols]
(3) Radiation heating device
(4) Heat treatment plate
(4a) First channel (hollow part)
(10) Second channel (pipe)
(11) Heat treatment plate
(12) Plate partition member
(20) Heat treatment plate
(21) Membrane partition member
(P) Object to be processed (substrate)

Claims (3)

A heat treatment plate on which a plate-like object to be treated is placed and a radiant heating device for radiatively heating the object to be treated on the heat treatment plate are provided, and a plurality of flow paths are provided inside the heat treatment plate, and different temperatures are provided. by the heat medium that flows to switch to a different flow path and radiation device, characterized in that it is adapted to heat treatment stepwise temperature change an object to be processed placed on the heat processing plate Heat treatment equipment. A process of changing the temperature of the object to be processed by the first heat medium flowing in the flow path to the object to be processed placed on the heat treatment plate to be processed in which a plurality of channels are formed, and a radiation heating device. a step for temperature changes, a treated product, further comprising a step to a temperature change an object to be processed by passing through the second heat medium different temperature and the first heat medium to the different flow paths, at least one of the heat medium A heat treatment method characterized by being a temperature for heating an object to be treated.   The method according to claim 2, wherein at least one of the temperature changes caused by the heat medium is cooling.

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