JPH023108Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an improvement of a walking beam heat treatment furnace that continuously transports electronic parts such as semiconductor parts and printed parts into the furnace for heat treatment. .

[Conventional technology]

Conventionally, in the heat treatment furnace for heat-treating electronic components as described above, the electronic components to be heat-treated (hereinafter referred to as objects to be heated) are placed on a mesh belt made of a heat-resistant metal material, and the mesh belt is driven by a drive device. Accordingly, the object to be heated is continuously transported into a furnace having a predetermined temperature distribution to perform the required heat treatment.

However, in such a heat treatment furnace, it is impossible to avoid sliding between the mesh belt and the belt guide when the mesh belt is driven, so the metal oxide scale that occurs on the surfaces of the mesh belt and belt guide comes off due to this sliding friction, and the friction described above causes the metal oxide scale to come off. It has been difficult to heat-treat electronic components with high purity because the generated metal powder scatters inside the furnace and contaminates the atmosphere inside the furnace.

In addition, as a conveying means that does not involve sliding as described above, there is a heat treatment furnace that uses a conventionally known so-called walking beam (shaking rod) type conveyance mechanism, and is usually used for heat treatment of steel billets and steel pipes. ing. This walking beam conveyance mechanism consists of a fixed beam consisting of a plurality of parallel bars whose positions are fixed, which pass through the furnace body from an inlet at one end to an outlet at the other end in the longitudinal direction of the long furnace body; It consists of a plurality of parallel bars that run parallel to the fixed beam and pass through the furnace body in the same way as above, and the relative positions with respect to the fixed beam are top, bottom, front and front in the longitudinal direction.
It is equipped with a moving beam that is displaceable at the rear. The movable beam is then driven by a drive device to periodically displace the movable beam in the order of ascending, advancing, descending, and retreating relative to the fixed beam, thereby moving the object to be heated into the furnace main body. It is configured to gradually convey the material in the length direction of the furnace while transferring the material between the two beams.

This conventional walking beam transport mechanism has
In order to prevent the beam materials from bending due to the high temperature inside the furnace and hindering the conveyance of the heated material, each beam material is placed vertically up from the bottom of the furnace at several points along the length of the furnace. A plurality of reinforcing columns are provided to support the beam at several points along its length, but since each reinforcing column of the moving beam moves together with the moving beam,
A plurality of through holes that widened in the moving direction were provided on the bottom side of the furnace, spaced apart from each other in the length direction, and each of the reinforcing columns of the moving beam was passed through these through holes, and the lower end of each column was placed outside the furnace. It is supported by a moving beam.

A water sealing mechanism or a mechanical sealing mechanism is provided to seal the above-mentioned through-hole with water to isolate the inside and outside of the furnace.

[Problem that the invention attempts to solve]

As mentioned above, a heat treatment furnace using a mesh belt conveying mechanism is not suitable for heat treatment of electronic components that require high purity because the atmosphere inside the furnace is likely to be contaminated. Further, the conventional heat treatment furnace using the walking beam conveyance mechanism has the following problems and has not been used for heat treatment of electronic components.

(1) Since both of the beams are made of steel, metal oxide scale forms on the surface of the beam, and the flaking of this scale contaminates the inside of the furnace. Furthermore, since beams made of steel do not have sufficient resistance to plastic deformation at high temperatures, that is, creep strength, reinforcing supports as described above are required.

(2) If a water seal mechanism is used to close the through hole on the bottom side of the furnace through the reinforcing column of the moving beam, the atmosphere inside the furnace will deteriorate due to water vapor. Further, in those using a mechanical sealing mechanism, the atmosphere inside the furnace is contaminated by dust generated from the sliding parts.

(3) Because there are the above-mentioned through holes and the base of the fixed beam reinforcing column on the bottom side of the furnace, it is not possible to uniformly install the heaters on the bottom side of the furnace to prevent uneven heating. Therefore, heating is performed only from the upper side of the furnace, and the heating efficiency decreases, so it is necessary to increase the length of the furnace.

The purpose of the present invention is to provide a walking beam heat treatment furnace that can keep the atmosphere inside the furnace extremely clean and can continuously perform heat treatment of high-purity electronic components when the object to be heated is transported inside the furnace for heat treatment. It is in.

[Means for solving problems]

The structure of the present invention for solving the above problems will be explained below with reference to FIGS. 1A and 1B to FIG. 3, which correspond to embodiments.

The walking beam heat treatment furnace of the present invention includes a long furnace body 5 having a furnace inlet at one end and an outlet at the other end, equipped with a heater 2, and having a predetermined temperature distribution in the longitudinal direction of the furnace. , a fixed beam 6 consisting of a plurality of parallel bars whose positions are fixed, which penetrates the inside of the furnace body 5 in the length direction; A movable beam 9 is made up of a plurality of parallel bars and is disposed so that its relative position with respect to the fixed beam 6 can be displaced upward, downward, and forward and backward in the longitudinal direction; Comprising moving beam drive mechanisms 30A and 30B that periodically displace the beam in the order of ascending, advancing, descending, and retreating,
In a walking beam type heat treatment furnace in which the object to be heated W is transferred between the beams 6 and 9 by the displacement movement of the moving beam 9 and is transferred within the furnace body 5 for heat treatment, the inner surface of the furnace body 5 The sides are covered with a covering material made of heat-resistant ceramic or quartz, and both the fixed beam 6 and the movable beam 9 are mainly made of heat-resistant ceramic material, and both beams 6 and 9 are both covered with a coating material made of heat-resistant ceramic or quartz. This is a walking beam type heat treatment furnace in which both ends of the furnace body 5 are supported by supporting members 7 or 10 outside the furnace body 5, without being supported inside the furnace body.

[Effect of invention]

In the walking beam heat treatment furnace configured as described above, the inner surface of the furnace body 5 is covered with the coating material 4, so that impurities are effectively prevented from entering the furnace from the inner surface. In addition, since both the fixed beam 6 and the movable beam 9 are mainly made of heat-resistant ceramic material, there is no generation of scale due to oxidation on the surface, no generation of dust when they come into contact with the heated object, and they have good rigidity and creep at high temperatures. The strength is also high enough. Further, both of the beams 6 and 9 are supported only on the outside of the furnace body 5 at both end sides, and there are no contact parts or sliding parts inside the furnace body 5 with the object conveying mechanism. . Therefore, from this aspect as well, impurities are prevented from being generated in the furnace. As described above, the atmosphere inside the furnace is extremely clean, and high-purity heat treatment is performed. In addition, since there is no beam support member inside the furnace body 5, the heaters 2 can be uniformly arranged on the lower side of the furnace even though it is a walking beam conveyance type furnace, allowing heat treatment with extremely high heating efficiency. will be held. Furthermore, since there is no through hole on the bottom side of the furnace through which the beam support member passes outside the furnace, there is no need for means for sealing the through hole, and there is no fear of impurities entering the furnace from the sealing means.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIGS. 1A and B, 1 is a long furnace body with a rectangular cross section, 2 is a heater arranged in the length direction on the top side and bottom side of this furnace body 1, and 3 is this heater 2. A heat insulating material 4 is provided between the heater 2 and the outer wall of the furnace body 1, and 4 is a covering material made of heat-resistant ceramic or quartz that is pasted to cover the surfaces of the heater 2 and the heat insulating material 3. A main body 5 is configured. 5a is the inlet of the furnace, 5b
is the exit.

Next, a walking beam conveyance mechanism for conveying the object to be heated from the inlet 5a to the outlet 5b of the furnace will be described. Reference numeral 6 denotes a fixed beam made of two or more parallel bars whose positions are fixed and which penetrate the inside of the furnace body 5 in the length direction from the furnace inlet 5a to the outlet 5b. This fixed beam 6 has high heat resistance and rigidity at high temperatures.
The base material is a heat-resistant ceramic material such as silicon nitride material with high creep strength, and the outer periphery of the base material is coated with quartz to suppress deflection due to high temperatures and to prevent dust generation due to contact with heated objects. It's getting old. Reference numeral 7 denotes a support member that is erected on the base 8 and supports both ends of the fixed beam 6 at a position outside the furnace. Similarly to the fixed beam 6, 9 is a movable beam made of two or more parallel bars that penetrates the inside of the furnace body 5 in the length direction from the inlet 5a to the outlet 5b of the furnace. The movable beam 9 is constructed of the same material as the fixed beam 6 described above, and in this embodiment, as shown in FIG. It is made of parallel bars. Reference numeral 10 indicates a support member that supports both ends of the moving beam 9 at a position outside the furnace, and reference numeral 11 indicates a moving frame to which the support members 10 are attached to both ends.

Next, a driving mechanism for driving the moving beam 9 up and down and forward and backward in the length direction will be described. First, let's talk about the up/down drive mechanism: 12.
Reference numeral 12 denotes link support members erected on the base 8 corresponding to positions close to both ends of the movable frame 11;
Reference numerals 3 and 13 indicate approximately L-shaped links that are respectively supported by these support members; 14 and 14 are rollers that are respectively supported by one end of these links and support the movable frame 11; and 15 are two links 13. It is a link bar that connects the other ends of the . 16 is base 8
The cylinder support member 17 provided above is a cylinder supported by this support member, and the connecting rod of this cylinder is connected to one link 13 and a link bar 15.
is connected to the connecting end of. As described above, the up/down drive mechanism 30A is configured.

Next, referring to the forward/backward drive mechanism of the moving beam 9, reference numeral 18 is a drive motor, 19 is a drive rotation shaft connected to the rotation shaft of this motor, and around this drive rotation shaft, there is a shaft extending over almost the entire length. A male thread is cut. Support plates 20 and 20 rotatably support both ends of the drive rotation shaft 19, and 21 is a guide shaft held between the support plates 20 and 20 in parallel to the drive rotation shaft 19. Reference numeral 22 includes a screw member that is screwed onto the drive rotation shaft 19 and a fitting member that is slidably fitted onto the guide shaft 21.
This screw member 22 is connected to a connecting portion protruding from one end of the movable frame 11 . The forward/backward drive mechanism 30B is configured as described above.

Next, the operation of the heat treatment furnace configured as described above will be described. In this heat treatment furnace, when the object to be heated is transported inside the furnace, power is supplied to the heater 2 to raise the temperature inside the furnace to a predetermined temperature. Initially, the movable beam 9 is positioned below the fixed beam 6 as shown in FIGS. 1A and 1B. To do this, the cylinder 17 is driven by a drive source (not shown) and the rings 13, 13 interlocked by the link bar 15 are rotated clockwise, thereby lowering the rollers 14, 14 and lowering the movable frame 11. Further, by operating the motor 18 at a relatively high speed and driving the screw member 22, the movable frame 11 is quickly moved in the direction of the arrow L, and the movable beam 9 is moved to a predetermined position in the direction of conveying the heated object. Let it retreat until.

After making the above preparations, the object W to be heated is placed on the fixed beam 6 on the entrance 5a side of the furnace. Then, the cylinder 17 is driven in the opposite direction to the above, and the links 13, 13 are rotated counterclockwise to rotate the roller 1.
4 and 14, the moving beam 9
to rise. During this rising process, the object to be heated W placed on the fixed beam 6 is pushed up by the moving beam 9 and separated from the fixed beam 6 by the moving beam 9.
is maintained by FIGS. 2A and 2B show this movement of the object to be heated. Then motor 1
8 is operated at low speed for a predetermined period of time and the screw member 22 is driven in the opposite direction to that described above, the moving beam 9 is gradually moved by a predetermined distance D in the direction of arrow R. Thereby, as shown in FIG. 2A, the object to be heated W is gently transported by a distance D in the transport direction. Next, by driving the cylinder 17 as in the beginning and lowering the rollers 14, 14 through the rings 13, 13, the moving beam 9 is moved to the initial low position as shown in FIGS. 2A and 2B. lower to. In this lowering process, the object to be heated W is transferred from above the moving beam 9 to above the fixed beam 6, contrary to the above. After this, as mentioned at the beginning, the motor 18
is operated at high speed to drive the screw member 22 and quickly retreat the moving beam 9 to its initial predetermined position.

As described above, the movable beam 9 is repeatedly driven with respect to the fixed beam 6, with one cycle of movement and displacement as shown in FIG. The reason for slow forward movement and rapid backward movement in this drive is to improve linearity so that the temporal heating characteristic curve does not become step-like. Due to the periodic displacement movement of the moving beam 9, the object W to be heated is gradually transported in the conveying direction through the furnace by the distance D, passes through a predetermined temperature range in a predetermined time, and undergoes the required heat treatment. receive.

To describe the specific data of the heat treatment furnace of this example, the furnace height is 10 cm, the furnace width is 45 cm, the furnace length is 350 cm,
The temperature of the high temperature part inside the furnace is 875℃, the heating power is 8KW,
Class 20 to 30 was obtained as the furnace cleanliness level, which indicates the cleanliness of the furnace atmosphere. This is a significantly higher level of cleanliness than conventional mesh belt conveyor furnaces, which have an internal cleanliness level of ¹⁰⁶ or more.

In the above-described embodiment, both the fixed beam and the movable beam were formed by covering the outer periphery of a bar made of heat-resistant ceramic with quartz, but the covering with quartz may be omitted.

[Effect of idea]

As mentioned above, according to the walking beam type heat treatment furnace of the present invention, since both the fixed beam and the moving beam are formed mainly from heat-resistant ceramic material, there is no possibility of scale formation due to oxidation of the surface of the beam material, and of the objects to be heated. There is no generation of dust when they come into contact with each other, and sufficient rigidity and creep strength at high temperatures can be obtained. Further, since both the fixed and moving beams are supported only on the outside of the furnace body at both ends thereof, there is no contact or sliding of the object conveying mechanism with respect to the inside of the furnace body. Therefore, from this aspect as well, it is possible to effectively prevent impurities from being generated in the furnace. Furthermore, since the inner surface of the furnace body is covered with a coating material made of heat-resistant ceramic or quartz,
It is also possible to effectively prevent impurities from entering the furnace from the inner surface side. As described above, the atmosphere inside the furnace can be made extremely clean, and high-purity electronic component heat treatment can be performed.

In addition, the heat treatment furnace of the present invention does not have a beam support part inside the furnace body, so even though it is a walking beam conveyance type furnace, the heaters can be uniformly arranged on the bottom side of the furnace, allowing heating. Heat treatment can be performed with extremely high efficiency. Furthermore, since there is no through hole on the bottom side of the furnace through which the beam support member passes outside the furnace, there is no need for means for sealing the through hole, and there is no fear of impurities entering the furnace from the sealing means.

[Brief explanation of drawings]

Fig. 1A is a partially longitudinal front view showing an outline of an embodiment of the present invention, Fig. 1B is a side view of the same embodiment, and Figs. 2A and B are front views respectively illustrating the walking beam type conveyance operation. The figure, side view, and FIG. 3 are explanatory diagrams showing how to drive the displacement of the moving beam in the present invention. 2... Heater, 4... Covering material, 5... Furnace body,
6...Fixed beam, 7...Fixed beam support member,
9...Moving beam, 10...Moving beam support member, 30A...Upper/lower drive mechanism, 30B...Forward/backward drive mechanism, W...Object to be heated.

Claims (1)

[Claims for Utility Model Registration] (1) A long furnace body having a furnace inlet at one end and an outlet at the other end, equipped with a heater, and having a predetermined temperature distribution in the longitudinal direction of the furnace; A fixed beam consisting of a plurality of parallel bars whose positions are fixed and which penetrates the inside of the furnace body in the length direction; and a plurality of parallel bars which penetrate the inside of the furnace body in the length direction in parallel with the fixed beam. The position relative to the fixed beam is top, bottom, front and front in the length direction.
The movable beam is provided with a movable beam that is disposed to be laterally displaceable, and a movable beam drive mechanism that periodically displaces the movable beam in the order of ascending, advancing, descending, and retreating relative to the fixed beam. In a walking beam heat treatment furnace in which the object to be heated is transferred between the two beams and heat-treated by the displacement movement of the beam, the inner surface of the furnace main body is coated with heat-resistant ceramic or quartz. Both the fixed beam and the movable beam are mainly made of heat-resistant ceramic material, and neither of the beams is supported inside the furnace body, and both ends of each beam are covered with the furnace body. A walking beam heat treatment furnace characterized by being supported by a support member on the outside. (2) The walking beam type heat treatment furnace according to claim 1, wherein both the fixed beam and the moving beam are formed by coating the outer periphery of a rod-shaped heat-resistant ceramic material with quartz.