JP4448749B2 - Heating and cooling device - Google Patents

Description

  The present invention relates to a heating / cooling apparatus for heating and cooling an object to be processed, for example, a soldering apparatus.

  Conventionally, as a soldering apparatus which is an example of a heating and cooling apparatus, there is one disclosed in Patent Document 1, for example. In this soldering apparatus, a hot plate and a cooling plate are provided in the chamber. The hot plate has a heating means inside, and a substrate or the like can be arranged on the surface. The cooling plate has a contact surface that can contact the back surface of the hot plate, the contact surface is formed so as to be able to advance and retreat with respect to the back surface of the hot plate, and the cooling water passes through the inside. With the contact surface of the cooling plate in non-contact with the back surface of the hot plate, the substrate and the electronic component are disposed on the surface of the hot plate with solder interposed. The chamber is evacuated and the heating means is heated to melt the solder. By heating in the exhaust state, the voids contained in the solder can be removed from the solder. After that, the heating is stopped, the contact surface of the cooling plate is brought into contact with the back surface of the heating plate, the cooling water is passed through the cooling plate, the substrate is cooled, the molten solder is solidified, the substrate and the electronic Solder parts.

JP 11-233934 A

  In this soldering apparatus, the cooling capacity of the cooling plate is determined by the degree of contact between the contact surface of the cooling plate and the back surface of the hot plate. Therefore, the flatness of both has been increased so that the contact surface of the cooling plate and the back surface of the hot plate are in contact with each other without a gap. However, when mass-producing this soldering device, it is quite difficult to make the flatness of the contact surface of the cooling plate and the back surface of the hot plate uniform in all mass-produced soldering devices. was there. Further, depending on the soldering apparatus, the flatness of the contact surface of the cooling plate and the back surface of the hot plate may not be completely matched, the cooling rate of the hot plate may not be uniform, and there may be a temperature distribution.

  An object of the present invention is to provide a heating and cooling device in which each cooling capacity is substantially uniform even in mass production, and the temperature distribution and cooling efficiency during cooling are improved.

A heating and cooling device according to the invention, for example a soldering device, has a chamber. It is desirable that the chamber can be opened and closed. A heating element is provided in the chamber. The heating element has a portion on which an object to be processed, such as a printed circuit board or IC package, and an electronic component or element with solder interposed, is placed. The heating body is preferably formed in a plate shape, for example. The heating body includes a heating means for the object to be processed. It is desirable that the heating body is composed of a good heat conductor that incorporates heating means and conducts heat from the heating means. As a heating means, for example, an electric heater that conducts heat by directly contacting the heating body can be used. Alternatively, as the heating means, a radiation means that conducts heat to the heating body by heat radiation without directly contacting the heating body, for example, a lamp heater can be used. A cooling body is also provided in the chamber. The cooling body has a contact surface that can come into contact with the heating body, and can move forward and backward with respect to the heating body. The cooling body is also preferably formed in a plate shape, for example, and its contact surface is preferably in contact with one surface of the heating body, for example, a surface other than the object to be processed. The cooling body is also preferably made of a good heat conductor, and it is desirable that the cooling fluid flow inside the cooling body. A gas is supplied to the chamber when the object to be processed is heated by the heating body. A groove is provided in the cooling body or the heating body. This groove opens to the contact surface side of the cooling body. A pressure reducing means communicates with the groove, and the groove is depressurized from the pressure in the chamber in a state where the contact surface of the cooling body is in contact with the heating body.

  In the heating and cooling apparatus configured as described above, in order to cool the object to be processed, the groove is depressurized from the inside of the chamber by the depressurization means in a state where the contact surface of the cooling body is in contact with one surface of the heating body. ing. Therefore, the heating body is pressed against the cooling body by the pressure in the chamber, and one surface of the heating body is firmly in contact with the contact surface of the cooling body, so that the cooling efficiency can be increased, and the cooling state varies depending on the location of the heating body. There is almost no temperature distribution. In addition, since the pressure difference between the groove in the cooling body and the chamber is used, the degree of adhesion between the cooling body and the heating body is almost the same in both mass-produced heating and cooling devices, and there is a difference between individual products. Less. If the inside of the chamber is at atmospheric pressure during cooling, a vacuum pump can be used as decompression means.

  One or more non-annular grooves can be provided. For example, as will be described later, a comb shape in which a plurality of radial grooves are provided, a first groove extending from an exhaust port connected to the exhaust means, and a plurality of second grooves formed at intervals along the first groove Or a plurality of comb-shaped grooves. For example, when a plurality of annular grooves are provided concentrically, it is considered that a vacuum state is formed on the inner side of the outermost annular groove, resulting in poor heat conduction. However, when the groove is provided in a non-annular shape, the above-described state is not achieved, and heat conduction is performed satisfactorily.

  The groove may have a plurality of main grooves provided radially from the communication position to the decompression means toward the outside of the contact surface. If comprised in this way, it can depressurize in the various positions of a contact surface, and can press a heating body equally.

  Furthermore, the said groove | channel can form several subgrooves at intervals in the length direction of each said main groove so that each may make a predetermined angle with respect to each said main groove. By providing the sub-groove, the total area of the groove including the main groove and the sub-groove increases. As a result, the force with which the cooling body and the heating body are pressed against each other increases, and the cooling efficiency increases. Further, since the sub-grooves are formed between various positions on the contact surface and the main grooves and are depressurized by the decompression means, the gas in the chamber flows into the main grooves from the sub-grooves at these various positions. However, cooling due to this inflow also occurs over the entire contact surface of the cooling body. Therefore, the cooling effect can be further enhanced.

  As described above, according to the present invention, the cooling efficiency can be increased, and the individual difference in the cooling effect can be reduced even in mass production.

  The soldering apparatus of one embodiment of the present invention has a chamber 2 as shown in FIG. A lid 6 is attached to the upper portion of the chamber 2 by a hinge 4 so as to be opened and closed. When the lid 6 is closed, the inside of the chamber 2 is configured to be airtight.

  A heating body, for example, a hot plate 8 is disposed in the chamber 2. The heat plate 8 is formed in a flat rectangular parallelepiped shape made of a material having good heat conduction, for example, graphite, and a heating means, for example, an electric heater 10 is provided in contact with the inner surface of the heat plate 8. . Electric wires 12 and 12 extending from the electric heater 10 are led out of the chamber 2 through the airtight terminals 14 and 14 and connected to a control device (not shown). Although not shown in the drawing, temperature detecting means, for example, a temperature detecting element is provided in the hot plate 8, and the energization of the electric heater 10 is controlled so that the temperature of the hot plate 8 becomes a predetermined temperature based on the detected temperature. Controlled by the device. An object to be processed 16 is placed on one surface of the hot plate 8, for example, the upper surface 8a. The workpiece 16 includes, for example, a printed circuit board and an electronic component arranged at a predetermined position of the printed board via solder.

  A cooling body, such as a cooling plate 18, is disposed below the hot plate 8 in the chamber 2. The cooling body 18 is formed in a flat rectangular parallelepiped shape made of, for example, a material having good heat conduction, such as aluminum, and has a contact surface, for example, an upper surface 18a sized so as to be in contact with the lower surface of the hot plate 8. The upper surface 18 a is formed in the same shape as the lower surface of the hot plate 8. The inside of the cooling body 18 is formed hollow. Lifting rods 20 and 20 are attached to the lower surface of the cooling plate 18. The elevating rods 20, 20 penetrate the bottom of the chamber 2 in an airtight and slidable manner, and support the cooling plate 18. Ends of the lifting rods 20, 20 outside the chamber 2 are coupled to the connecting body 22. Driving means, for example, a cylinder 24 is attached to the bottom surface of the bottom of the chamber 2, and a rod 24 a thereof is coupled to the connecting body 22. Therefore, as the rod 24a of the cylinder 24 advances and retreats, the cooling plate 18 moves up and down, and takes either a state in which the lower surface 18a thereof is in contact with the lower surface of the hot plate 18 or a non-contact state. The elevating rods 20 and 20 are hollow, cooling water is supplied into the cooling plate 18 through one of them, and cooling water is discharged through the other. Thereby, the cooling plate 18 is cooled.

  The space in the chamber 2 is connected to exhaust means, for example, a vacuum exhaust pump 28 via a valve 26. By operating the vacuum pump 28, the chamber 2 can be evacuated. In addition, an inert gas and / or a reducing gas is supplied into the chamber 2 via a valve 30.

  Grooves 32 are formed in the upper surface 18a of the cooling plate 18 as shown in FIG. A plurality of, for example, a total of four main grooves 32a are formed from the center of the upper surface 18a of the cooling plate 18 to the edge of the upper surface 18a, for example, a total of four main grooves 32a along two diagonal lines of the upper surface 18a. . These main grooves 32 a are open on the upper surface 18 a side of the cooling plate 18. A plurality of sub-grooves 32b are formed for each of the main grooves 32a. These sub-grooves 32b are located on both sides of the main groove 32a with a gap in the length direction of the main groove 32a, and are measured at a predetermined angle with respect to the main groove 32a, for example, from the outer end side of the main groove 32a. It is formed to form an acute angle. The sub-groove 32 b is also opened on the upper surface 18 a of the cooling plate 18. The main groove 32a and the sub-groove 32b are formed to have a width of 5 mm and a depth of 3 mm, for example.

  The starting point of each main groove 32a at the center of the upper surface 18a of the cooling plate 18 is an exhaust port, and decompression means, for example, vacuum exhaust, is provided via a passage 34 inside the cooling plate 18, a conduit 36, and a valve 38 outside the chamber 2. Connected to the pump 40.

  When performing soldering by this soldering apparatus, first, the lid 6 is opened, the workpiece 16 is placed on the upper surface 8a of the hot plate 8, and the lid 6 is closed. The valve 26 is opened and the evacuation pump 28 is operated to evacuate the chamber 2 sufficiently. Next, while the valve 30 is opened to introduce inert and / or reducing gas, the operation of the vacuum pump 28 is continued to bring the chamber 2 into an oxygen-free state or a low oxygen concentration state.

  When the electric heater 10 is energized, the temperature of the hot plate 8 is rapidly increased because the heat capacity is small, and the workpiece 16 is heated to a temperature suitable for soldering, for example, 230 degrees Celsius. As a result, the solder of the workpiece 16 is melted. At this time, since the inside of the chamber 2 is almost in a vacuum state, voids in the molten solder are ejected from the solder.

  Next, energization to the electric heater 10 is stopped, and the amount of gas supplied from the valve 30 is increased to increase the pressure in the chamber 2 until the pressure becomes almost atmospheric pressure. Next, the cylinder 24 is operated, the cooling plate 18 is raised, and the upper surface 18 a is brought into contact with the lower surface of the hot plate 8. At this time, when the valve 38 is opened and the evacuation pump 40 is driven, the groove 32 becomes negative pressure and the hot plate 8 is pressed by the atmospheric pressure of the cooling plate 18. As a result, the upper surface of the cooling plate 18 and the lower surface of the hot plate 8 are in close contact. Even in the state where the vacuum pump 40 is operated, the supply of gas from the valve 30 and the operation of the vacuum pump 28 are performed so that the inside of the chamber 2 is maintained at substantially atmospheric pressure.

  In this state, when cooling water is supplied into the cooling plate 18, the upper surface of the cooling plate 18 and the lower surface of the hot plate 8 are in close contact with each other. The temperature of the plate 8 rapidly decreases to near normal temperature, and the solder solidifies. At this time, since the gas is supplied and the vacuum pump 40 is driven, the gas flows into each sub-groove 32b as shown in FIG. Since each sub-groove 32b is formed so as to branch from the radially formed main groove 32a, gas flows through the entire area of the upper surface 18a of the cooling plate 18 to further enhance the cooling effect, and the temperature differs on the upper surface 18a. It becomes difficult to happen.

  For example, it is conceivable to form a plurality of sub-grooves concentrically with a rectangular annular groove connecting the main grooves 32a. However, when formed in this way, the inner side of the outermost square annular groove is in a vacuum state and the heat conduction is considered to be worse, so the arrangement of the grooves is made so that the part surrounded by the grooves is not formed It is desirable to take a radial form.

  A solid line in FIG. 3 shows the temperature change of the hot plate 8 after the cooling of the hot plate 8 is started by the aluminum cooling plate in this embodiment. There was a temperature drop of about 2.15 degrees Celsius per second. The one-dot chain line in FIG. 3 shows the temperature change of the hot plate 8 when the vacuum pump 40 is not operated in this embodiment, and is about 1 second from the start of cooling. The temperature dropped only 1 degree Celsius. A broken line in FIG. 3 shows a change in temperature of the hot plate 8 when the cooling plate 18 is made of copper and the vacuum pump 40 is not operated, and is 1 second from the start of cooling. The temperature dropped only by about 1.56 degrees Celsius. In this way, by operating the vacuum pump 40 to bring the upper surface 18a of the cooling plate 18 into close contact with the lower surface of the hot plate 8, even if an aluminum cooling plate having lower thermal conductivity than copper is used, The temperature can be lowered more rapidly than when the cooling plate 18 is made of copper and the vacuum pump 40 is not operated.

  Further, immediately after the start of cooling, the temperature near the upper left in FIG. 2 of the hot plate 8 is 231 degrees, the temperature near the upper right is 227.9 degrees, the temperature near the lower left is 234.0 degrees, and the temperature near the lower right. Was 234.2. Therefore, the difference in temperature (temperature distribution) due to the difference in the location of the hot platen 8 is only 6.3 degrees (= 234.2 degrees-227.9 degrees) at the maximum. On the other hand, when measured without operating the vacuum pump 40, the temperature near the upper left is 233.8 degrees, the temperature near the upper right is 224.4 degrees, the temperature near the lower left is 236.5 degrees, and the temperature near the lower right Was 234.4 degrees. Therefore, the difference in temperature due to the difference in the location of the hot plate 8 was 12.1 degrees (= 236.5 degrees-224.4 degrees) at the maximum. When the cooling plate is made of copper and the vacuum exhaust pump 40 is not operated, 235.3 degrees near the upper left, 228.1 degrees near the upper right, 230.2 degrees near the lower left, and 242 near the lower right. It was 3 degrees. Therefore, the difference in temperature due to the difference in the location of the hot plate 8 was 14.3 degrees (= 242.3 degrees-228.1 degrees) at the maximum. From these results, according to the present embodiment, almost the same temperature is obtained in the entire area of the hot plate 8, and the solder of the workpiece 16 on the hot plate 8 can be cooled with almost the same temperature drop. It is possible to prevent variation in the solidified state.

  In the above-described embodiment, four main grooves 32a are provided. However, the number thereof is arbitrary. For example, only one main groove 32a may be provided, or a larger number of main grooves 32a may be formed than in the above-described embodiment. You can also. In the above embodiment, the main grooves 32a are provided radially. However, the present invention is not limited to this. For example, the first grooves extending linearly from one exhaust port formed in the upper surface 18a of the cooling plate 18 and the first grooves A comb-shaped groove in which a plurality of second grooves are formed so as to be orthogonal to the first groove with an interval in the length direction of one groove may also be used. Alternatively, a plurality of the comb-shaped grooves can be provided. Further, in the above-described embodiment, three sub-grooves 32b are provided in total, three on one side of the main groove and three on the other side. However, the number of sub-grooves 32b is arbitrary as long as it is plural, for example, more Can be provided for each main groove. In the above embodiment, the grooves 32 are formed in the cooling plate 18, but the grooves 32 can be formed on the surface of the hot plate 8 that contacts the cooling plate 18.

  In the above embodiment, the electric heater 10 that heats and cools not only the hot plate 8 but also the heater is used as the heating means. However, the present invention is not limited to this, and for example, a lamp heater can be used. The electric heater has a large heat capacity and takes time for heating and cooling. In addition, since heat conduction is performed by contact with the hot plate 8, an electric heater needs to be embedded in the hot plate 8, which requires precise processing. In addition, when the electric heater 10 is heated, the heater 10 is thermally expanded, the manner of contact with the hot plate 8 is changed, and temperature distribution is likely to occur in the hot plate. On the other hand, when a lamp heater having a smaller heat capacity than that of the electric heater is used instead of the electric heater, the lamp heater conducts heat to the hot plate 8 by infrared radiation, so that contact with the hot plate 8 is not necessary. Thereby, only the hot plate 8 is to be cooled, the heat capacity is reduced, and the cooling efficiency is improved. Therefore, compared to the case where an electric heater is used, temperature distribution is less likely to occur, and it is not necessary to make contact with the heat plate 8 when it is mounted.

  In the above embodiment, the present invention is implemented in the soldering apparatus, but the present invention is not limited to this. For example, the present invention can be implemented in a resin curing apparatus, an annealing furnace, a drying furnace, and the like.

It is a schematic block diagram of the soldering apparatus of one Embodiment of this invention. It is a top view of the cooling plate used with the soldering apparatus of FIG. 2 is a temperature profile in a state where the vacuum exhaust pump is operated, a state where the vacuum exhaust pump is not operated, and a state where the cooling plate is made of copper and the vacuum exhaust pump is not operated in the soldering apparatus of FIG. 1.

Explanation of symbols

2 Chamber 8 Hot plate (heating body)
10 Electric heater (heating means)
16 Object 18 Cooling plate (cooling body)
32 groove 40 vacuum pump (pressure reduction means)

Claims (4)

A chamber;
A heating body provided in the chamber, having a portion on which the workpiece is placed, and having a heating means for the workpiece;
A cooling body provided in the chamber so as to be capable of moving back and forth with respect to the heating body;
A groove provided on the contact surface side of the cooling body and provided in the cooling body or the heating body;
In a state where the contact surface of the cooling body is in contact with the heating body, the pressure reducing means for reducing the pressure of the groove from the pressure in the chamber;
A gas source for supplying gas into the chamber at the time of decompression by the decompression means;
Equipped,
The groove includes a plurality of main grooves extending radially outward from the communication port to the decompression unit, and a length along the length direction of the main grooves with respect to the length direction of the main grooves. A heating and cooling device having a plurality of sub-grooves formed by branching at an acute angle as measured from the outside of the main groove . A chamber;
A heating body provided in the chamber, having a portion on which the workpiece is placed, and having a heating means for the workpiece;
A cooling body provided in the chamber so as to be capable of moving forward and backward with respect to the heating body;
A groove provided on the contact surface side of the cooling body and provided in the cooling body or the heating body;
A pressure reducing means that communicates with the groove, and in which the contact surface of the cooling body is in contact with the heating body, the pressure in the groove is reduced from the pressure in the chamber;
A gas source for supplying gas into the chamber at the time of decompression by the decompression means;
Equipped,
The heating and cooling device is a comb-like shape in which the groove has a first groove extending from an exhaust port connected to the decompression unit and a plurality of second grooves formed at intervals along the first groove. . The heating and cooling device according to claim 2, wherein a plurality of the comb-shaped grooves are provided. The heating and cooling device according to any one of claims 1 to 3 , wherein the heating means radiates infrared rays into the heating body.

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