JP2019010648A - Heating and cooling device - Google Patents

Abstract

To provide a heating and cooling device capable of improving quality of soldering of a processed member.SOLUTION: A heating and cooling device 100 comprises: an air tight container 5; an induction heating device 3 for heating or cooling a processed member 1; a temperature sensor 13 for measuring temperature of the processed member 1; a pressure sensor 14 for detecting pressure in the container 5; a reduction gas supply device 9 for supplying reduction gas into the container 5; an inert gas supply device 10 for supplying inert gas into the container 5; a vacuum exhaust device 11 for reducing pressure in the container 5; and a controller 6 for controlling heating or cooling by the induction heating device 3 and pressure in the container 5 based on the measured temperature. The vacuum exhaust device 11 has a flow rate adjustment valve 11f for adjusting an exhaust flow rate of a gas on at least any one of branched exhaust pipings, and the controller 6 switches the exhaust pipings based on pressure in the container 5 and changes vacuum exhaust speed in multi stages.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heating / cooling device, and more particularly to a heating / cooling device suitable for a method of manufacturing a semiconductor module in which a semiconductor element is soldered to an insulating substrate.

  In recent years, semiconductor modules used as power conversion switching devices and the like have become very severe in environmental conditions. High bonding strength and high heat resistance are also required on the solder joint surface between the semiconductor chip such as IGBT (Insulated Gate Bipolar Transistor) and FWD (Free Wheeling Diode) and the insulating substrate, or the solder joint surface between the insulating substrate and the base plate. It is said that.

  Therefore, as a solder material, an Sn-Sb-based material that is easy to obtain a high bonding strength and has a high Sb concentration is being used instead of an Sn-Ag-based material that has excellent wettability but does not have sufficient bonding strength. is there.

  However, the Sn—Sb solder material has a property that the solder is difficult to wet because a thick oxide film is formed on the surface of the soldering member as compared with the Sn—Ag solder material. For this reason, the surface oxide film of the member to be soldered cannot be sufficiently reduced, and there is a problem that voids are easily generated on the solder joint surface.

  In order to solve this problem, in the method for manufacturing a member to be processed of Patent Document 1, the laminate is put into a joining and assembling apparatus equipped with a decompression furnace, the inside of the furnace is evacuated, and then the inside of the furnace is positively pressurized. The surface of each member of the laminate is reduced in a hydrogen atmosphere. After the solder is melted by heating, the inside of the furnace is again evacuated to remove the bubbles (caused by voids) in the solder plate, and then the inside of the furnace is again brought to a positive pressure hydrogen atmosphere to move the bubbles into the solder plate. (See paragraph 0048).

  Moreover, in the manufacturing method of the to-be-processed member of patent document 2, as shown in the following FIG. 5, the temperature and pressure in a chamber are changed. Specifically, (1) atmosphere gas sealing step, (2) low-pressure melting step, (3) pressurizing step, (4) re-depressurizing step, (5) re-pressurizing step, (6) temperature decreasing step In order. This prevents the void in the solder from bursting (paragraphs 0014 to 0021).

JP 2003-297860 A JP 2006-281309 A

  In the manufacturing method of the to-be-processed member of patent document 1, 2, in order to remove the void in the molten solder material, the inside of a container is evacuated. However, in this vacuum evacuation process, if evacuation is performed at a high speed, voids may expand and burst due to a sudden change in pressure, and solder may scatter and adhere to the insulating substrate and surrounding members. It was. On the other hand, when exhaust is performed at a low speed, there is a problem that the time required to reach the set pressure becomes long and the process time becomes long.

  In view of such a problem, an object of the present invention is to provide a heating / cooling apparatus capable of controlling the evacuation speed and improving the soldering quality of a member to be processed.

  In order to achieve the above object, a heating / cooling device of the present invention comprises an airtight container having an opening / closing mechanism capable of inserting and removing a member to be processed, a heating / cooling means for heating or cooling the member to be processed, and the member to be processed. A temperature sensor for measuring the temperature of the processing member, a pressure sensor for detecting the pressure in the container, a reducing gas supply means for supplying a reducing gas into the container, and an inert gas in the container An inert gas supply means, a vacuum exhaust means for depressurizing the inside of the container, and a control means for controlling heating or cooling by the heating / cooling means and a pressure in the container based on the temperature measured by the temperature sensor; In the heating / cooling apparatus, the vacuum exhaust means branches at least one of the branched exhaust pipes by branching a flow path of an exhaust pipe connected to a vacuum pump that exhausts the gas in the container A flow rate adjusting means for adjusting the exhaust flow rate of the gas is provided, and the control means switches the branched exhaust pipe based on the pressure in the container and changes the vacuum exhaust speed in multiple stages. .

  In the heating / cooling apparatus of the present invention, the member to be processed placed in an airtight container is heated or cooled by the heating / cooling means in an atmosphere of a reducing gas, which is suitable for soldering. Further, since the control means switches the exhaust pipe based on the pressure in the container and further changes the exhaust speed of the vacuum exhaust means in multiple stages, it is possible to improve the soldering quality of the member to be processed.

  In the heating and cooling apparatus of the present invention, the control means switches to an exhaust pipe provided with the flow rate adjusting means during a first period until the pressure in the container changes from atmospheric pressure to a preset first pressure. During the second period until the pressure in the container reaches the second pressure set in advance from the first pressure, switching to an exhaust pipe not provided with the flow rate adjusting means is performed and evacuating is performed. It is preferable to perform evacuation by switching to the exhaust pipe provided with the flow rate adjusting means again during the third period until the pressure in the container reaches the third pressure set in advance from the second pressure.

  According to the said aspect, a control means switches to the exhaust pipe (slow exhaust pipe mentioned later) provided with the flow volume adjustment means in the 1st period. By using the exhaust pipe provided with the flow rate adjusting means, it is possible to perform the vacuum exhaust while suppressing the speed while adjusting the exhaust flow rate. Thereby, it can prevent that the position of the semiconductor element of a to-be-processed member moves by rapid pressure change.

  In addition, the control means switches the flow path to an exhaust pipe (rough drawing pipe to be described later) in which no flow rate adjusting means is provided in the second period. By using the exhaust pipe not provided with the flow rate adjusting means, the speed of the vacuum exhaust can be increased and the exhaust time can be shortened.

  Further, the control means switches the flow path to the exhaust pipe provided with the flow rate adjusting means again in the third period. In the third period, a rapid pressure change does not occur by performing vacuum evacuation at a reduced speed, so that it is possible to simultaneously eliminate void reduction and solder scattering in the solder material.

  Further, in the heating and cooling apparatus of the present invention, the vacuum evacuation means branches the flow path of the exhaust pipe connected to the vacuum pump into three or more, and the flow rate adjusting means having different conductances in the branched exhaust pipes It is preferable that the control means performs vacuum exhaust so that a predetermined pressure is obtained at an exhaust speed corresponding to each step.

  The flow path of the exhaust pipe to which the vacuum pump is connected may be branched into three or more, and a flow rate adjusting means having a different conductance may be provided in each exhaust pipe. The control means can control the exhaust gas flow rate with higher accuracy by controlling each flow rate adjusting means.

It is related with one Embodiment of the heating-cooling apparatus of this invention, and is a schematic block diagram of the heating state of a to-be-processed member. It is a schematic block diagram of the cooling state of a to-be-processed member concerning one Embodiment of the heating-cooling apparatus of this invention. It is explanatory drawing which shows the state change of the temperature and pressure at the time of manufacturing a to-be-processed member. It is the figure which compared the process before and after a countermeasure. It is the figure which showed the void incidence rate. It is the figure which compared the solder scattering rate before and after a countermeasure. It is explanatory drawing which shows the state change of the temperature at the time of manufacturing a to-be-processed member in the conventional heating / cooling apparatus.

  Hereinafter, an embodiment of the heating and cooling apparatus of the present invention will be described with reference to FIGS. 1 and 2. 1 shows a heating state in which the member 1 to be processed is heated, and FIG. 2 shows a cooling state in which the member 1 to be processed is cooled. Only the position of the tray 2 on which the member 1 to be processed is placed is different.

  As shown in FIGS. 1 and 2, the inside of the container 5 of the heating / cooling device 100 mainly includes a member 1 to be processed, an induction heating device 3 for heating or cooling the member 1 to be processed, and a member 1 to be processed. A lifting / lowering device 16 (part) is provided that can be lifted and lowered while holding.

  Further, outside of the container 5, mainly, a refrigerant circulation device 4 that circulates a refrigerant inside the induction heating device 3, a control device 6 that controls heating or cooling of the processing target member 1, an input device 7, a reduction A gas supply device 9, an inert gas supply device 10, an evacuation device 11, and a lifting device 16 (part) are provided.

  The member 1 to be processed has one or more insulating substrates 1b (for example, Direct Copper Bond) laminated on the upper surface of a base plate 1a (for example, copper or aluminum) having excellent heat dissipation performance via a solder plate (not shown). In addition, a plurality of semiconductor elements 1c are arranged on the upper surface of the insulating substrate 1b via a solder plate (not shown).

  Then, when the solder plate is melted by the heat treatment, the semiconductor element 1c and the insulating substrate 1b, the insulating substrate 1b and the base plate 1a are brought into close contact with each other, and the solder is solidified and joined by the cooling treatment, whereby a power semiconductor device is manufactured. The In addition, the to-be-processed member 1 can be heated and cooled by heat conduction through a rectangular tray 2. Further, since the tray 2 is sufficiently larger than the member 1 to be processed, a plurality of members 1 to be processed can be set on the tray 2.

  In the induction heating device 3, magnetic field lines whose strength changes are generated by passing an alternating current through the induction heating coil 3 a. Since an eddy current flows through a conductor such as a metal disposed in the magnetic lines of force, the member to be processed 1 and the tray 2 can generate heat. The shape of the pipe forming the induction heating coil 3a is preferably a square shape in terms of increasing the contact area with the cooling plate 3b described later, but it may be a round pipe or an elliptical pipe.

  The induction heating device 3 includes a support plate 3c formed of an insulating material for supporting the induction heating coil 3a, and a ceramic material (for example, silicon carbide or nitride) covering the upper surface of the induction heating coil 3a. A cooling plate 3b formed of aluminum is provided. The cooling plate 3b is disposed in close contact with the induction heating coil 3a in which the refrigerant circulates by a tightening force of a bolt (not shown) so that the temperature is constant.

  The outer peripheral side surface of the induction heating coil 3a is covered with an insulating material having heat resistance (for example, PTFE (fluorine resin), polyimide, machinable ceramics) so that the support plate 16f of the lifting device 16 does not interfere with the upper surface. The insulating cover 3d is attached to the support plate 3c. Thereby, the conductive dust generated when the processing target member 1 and the tray 2 are attached / detached does not accumulate on the induction heating coil 3a during the long-time operation of the heating / cooling device 100, and a short circuit or discharge when an alternating current is applied. Can be prevented.

  In addition, a spacer 3e made of an insulating material is inserted between the pipes forming the induction heating coil 3a to prevent a short circuit or discharge that occurs when an alternating current is passed through the induction heating coil 3a. .

  Further, in the induction heating device 3, a temperature sensor 13 is inserted through a through-hole provided in the cooling plate 3b and the support plate 3c at a position where the induction heating coil 3a is not provided, and the bottom surface temperature of the tray 2 is set. Measurement is possible. The temperature sensor 13 is connected to the control device 6, and the temperature of the tray 2 measured by the temperature sensor 13 is input to the control device 6.

  In the refrigerant circulation device 4, the heat exchanger 4a and the induction heating coil 3a are connected by refrigerant pipes 4c and 4d through which the refrigerant circulates. A circulation pump 4b is arranged in the middle of the refrigerant pipe 4c, and the control device 6 adjusts the temperature and flow rate of the refrigerant circulating in the pipe of the induction heating coil 3a so as to adjust the heat exchanger 4a via the signal line j. And the circulation pump 4b. In general, fluid such as water, pure water, ultrapure water, or antifreeze is used as the refrigerant.

  The airtight container 5 includes a lid portion 5a, a bottom plate 5b, and a sealing material 5c provided on a contact surface between the lid portion 5a and the bottom plate 5b. The lid portion 5a is supported by a shaft 18 extended from the opening / closing actuator 17, and moves up and down together with the shaft 18, so that the lid 5a can be opened and closed with respect to the bottom plate 5b. The open / close actuator 17 is connected to the control device 6 via the signal line b.

  Inside the upper surface of the lid 5a, a heat insulating cover 5d for reflecting the infrared radiation radiated from the member 1 to be processed and re-entering the member 1 to be processed is attached. The heat shield cover 5d has a structure that does not hinder the heating of the member 1 to be processed by the induction heating coil 3a.

  The control device 6 includes at least storage means such as RAM, ROM, magnetic disk, or optical disk, and arithmetic means having a CPU. Based on the programs and data stored in the storage means, the control means 6 can control various devices. A control signal is transmitted.

  Further, the control device 6 is connected to an input device 7 and display means including a display (not shown). Data stored in the storage means of the control device 6 can be input from the input device 7. Data input from the input device 7 includes temperature profile data such as elapsed time g, target heating time h, target cooling time i, and the like.

  The temperature of the tray 2 measured by the temperature sensor 13 is also input to the storage unit of the control device 6. Based on the input temperature profile data, the control device 6 performs control so that the processing target member 1 is heated or cooled.

  The heating / cooling device 100 includes a reducing gas supply device 9 that supplies a reducing gas into the container 5. The reducing gas supply device 9 includes a reducing gas cylinder 9c, a supply pipe 9a for sending the gas in the reducing gas cylinder 9c to the inside of the container 5, and a supply valve 9b provided on the path of the supply pipe 9a. . Since the supply valve 9b is connected to the control device 6, the control device 6 can control the opening and closing. Note that hydrogen, formic acid, or the like can be used as the reducing gas.

  The heating / cooling device 100 includes an inert gas supply device 10 that supplies an inert gas into the container 5. The inert gas supply device 10 includes an inert gas cylinder 10c, a supply pipe 10a for sending the gas in the inert gas cylinder 10c to the inside of the container 5, and a supply valve 10b provided on the path of the supply pipe 10a. Has been. Since the supply valve 10b is connected to the control device 6, the control device 6 can control the opening and closing. Note that nitrogen or the like can be used as the inert gas.

  If the gas supplied from the reducing gas supply device 9 and the inert gas supply device 10 causes the pressure in the container 5 to exceed a value set in the pressure sensor 14 (for example, atmospheric pressure or higher), the inside of the container 5 The release valve 21 for releasing the pressure is opened. The discharge valve 21 is provided in the discharge pipe 22 and performs an opening / closing operation via the signal line f of the control device 6 so as to prevent the inside of the container 5 from being overpressured. The pressure sensor 14 is connected to a pressure gauge 19 provided outside the container 5.

  Next, the vacuum exhaust device 11 provided in the heating / cooling device 100 will be described. The vacuum pump 11h of the vacuum exhaust device 11 is connected to the inside of the container 5 by a main exhaust pipe 11a.

  A main exhaust valve 11b is provided in the middle of the main exhaust pipe 11a. Further, a roughing pipe 11c and a slow exhaust pipe 11e are provided so as to bisect the main exhaust pipe 11a. The roughing pipe 11c is provided with a roughing valve 11d, and the slow exhaust pipe 11e is provided with a flow rate adjusting valve 11f and a slow valve 11g that can be adjusted by reducing the exhaust flow rate.

  In the present embodiment, the roughing pipe 11c may be provided with a second flow rate adjusting valve having a small conductance different from the flow rate adjusting valve 11f.

  A main exhaust valve 11b, a roughing valve 11d, and a slow valve 11g provided on each exhaust pipe are connected to the control device 6 through signal lines c1 to c3. The vacuum pump 11h is connected to the control device 6 via a signal line d, and the pressure sensor 14 for measuring the pressure in the container 5 is connected to the control device 6 via a signal line k.

  When the atmosphere in the container 5 is reduced, the exhaust operation is performed while switching the operation of the vacuum pump 11h and the opening / closing operations of the main exhaust valve 11b, the roughing valve 11d, and the slow valve 11g according to the exhaust operation pattern preset in the control device 6. Do.

  Each exhaust pipe of the vacuum exhaust apparatus 11 shown in the figure is an example in which the flow path is bifurcated. However, when it is necessary to control the exhaust flow rate with higher accuracy, the number of branches is not limited to two and the number of branches is three or more. May increase.

  Next, the lifting device 16 provided in the heating / cooling device 100 will be described. In the lifting device 16, a lifting base 16 b formed in a flat plate shape is connected to a lifting actuator 16 a provided on the bottom plate 5 b of the container 5. A plurality of elevating shafts 16d fixed to the elevating base 16b and penetrating the bottom plate 5b can be moved vertically by elevating bearings 16c provided on the lower surface of the bottom plate 5b (for example, four corners of the elevating base 16b). Is provided.

  A pedestal 16e is provided on the other end side of the elevating shaft 16d, and a support plate 16f that connects the pair of pedestals 16e and holds the tray 2 on which the member 1 to be processed is placed is provided. It has been. The support plate 16f is formed of an insulating material having heat resistance (for example, engineering plastics or ceramics such as a polyimide or a peak plate), and even when the heated processing target member 1 and the tray 2 are held, the support plate 16f Heat is difficult to conduct.

  The support plate 16f is formed so as not to interfere with the cooling plate 3b and the insulating cover 3d of the induction heating device 3 when the lifting device 16 is lowered. The lifting device 16 configured as described above smoothly lifts and lowers the support plate 16f while holding the tray 2 on which the member 1 to be processed is held when the lifting actuator 16a starts the lifting operation in response to a command of the signal line e of the control device 6. be able to.

  In a state in which the member to be processed 1 is heated, the control device 6 is arranged so that the member to be processed 1 is in a non-contact state with the cooling plate 3b via the signal line e (see FIG. 1). The lifting actuator 16a is moved up. And the control apparatus 6 controls the energization current of the induction heating coil 3a, the frequency of alternating current, energization time, timing, etc. via the signal line a.

  In a state where the processing target member 1 and the tray 2 heated to a high temperature are cooled, the control device 6 is set to a set position (see FIG. 2) where the tray 2 comes into contact with the cooling plate 3b via the signal line e. Then, the lifting actuator 16a of the lifting device 16 described later is moved downward. By bringing the cooling plate 3b, which has been cooled in advance by the refrigerant circulating in the pipe of the induction heating coil 3a, into contact with the tray 2, heat exchange is performed between the processing target member 1 and the tray 2 in a high temperature state, and rapid Can be cooled to.

  In particular, it is known that when the molten solder of the member 1 to be treated is rapidly cooled to a temperature at which the solder is solidified, the solder crystals are dense and have good bonding quality. For this reason, it is preferable that the thickness of the cooling plate 3b is formed so as to be one or more times larger than the heat capacities of the processed member 1 and the tray 2, and the heat capacities thereof are increased.

  Next, with reference to FIG. 3, the operation | movement which solders a semiconductor module with the heating / cooling apparatus 100 is demonstrated based on the temperature state of the to-be-processed member 1, and a pressure state.

(1) Loading The lid 5a is raised by the opening / closing actuator 17, the container 5 is opened, and the member 1 to be processed is loaded. After the member 1 to be processed is placed on the tray 2, the lid 5 a is lowered by the opening / closing actuator 17 to close and seal the container 5.

(2) Vacuum exhaust Pressure that is connected to the pressure sensor 14 by opening the main exhaust valve 11b, the slow valve 11g, and the roughing valve 11d of the vacuum exhaust device 11, and evacuating the inside of the container 5 using the vacuum pump 11h. When the value of the total 19 reaches a predetermined degree of vacuum (P1 pressure in the figure), the main exhaust valve 11b, the slow valve 11g, and the roughing valve 11d are closed.

(3) Introduction of reducing gas The supply valve 9b of the reducing gas supply device 9 is opened to supply the reducing gas from the reducing gas cylinder 9c to the container 5. Thereafter, when the inside of the container 5 reaches a predetermined pressure (atmospheric pressure) by the pressure gauge 19, the supply valve 9b is closed.

(4) Heating (solder melting and reduction treatment)
The induction heating device 3 is used to control heating while measuring the value of the temperature sensor 13 so that the tray 2 on which the processing target member 1 is placed reaches the first target heating temperature T2. The control device 6 can feedback control the output of the heating / cooling device 100 so as to minimize the deviation between the first target heating temperature T2 and the measured temperature T of the temperature sensor 13.

  Since the heating / cooling device 100 of the present invention is a method of directly heating the processing target member 1 as a heating element using the induction heating coil 3a, there is an advantage that the temperature raising rate is fast. Thereby, heating time can be shortened and the processing capacity of the heating and cooling apparatus 100 can be increased.

(5) Pressure reduction operation (void removal)
When a predetermined time elapses when the member to be processed 1 is at the temperature T2, the pressure in the container 5 is reduced in order to degas the void in the solder material of the member 1 to be processed. In the region where the pressure in the container 5 is from atmospheric pressure to P4 (about 50 kPa to 20 kPa, the “first pressure” of the present invention), the exhaust flow rate is set so that the position of the semiconductor element 1c of the member 1 to be processed does not deviate from the predetermined position. The main exhaust valve 11b and the slow valve 11g of the evacuation apparatus 11 are opened to perform evacuation using the flow rate adjustment valve 11f that adjusts the flow rate.

  The flow rate adjusting valve 11f adjusts the exhaust speed so that the time t1 (the “first period” of the present invention) in which the inside of the container 5 reaches the pressure P4 is about 5 seconds. When the inside of the container 5 reaches the pressure P4, in the region up to P3 (about 5 kPa to 2 kPa, the “second pressure” of the present invention), the roughing valve 11d is opened, and vacuum exhausting is performed by the roughing pipe 11c. . Thereby, the exhaust time t2 (the “second period” of the present invention) can be shortened.

  When the pressure inside the container 5 reaches the pressure P3, the roughing valve 11d is closed in the region up to P2 (about 1 kPa to 0.5 kPa, the “third pressure” of the present invention), and the vacuum exhaust device is operated by the flow rate adjustment valve 11f. 11 main exhaust valve 11b and slow valve 11g are opened to perform evacuation.

  In the evacuation operation in this region, when the void in the molten solder material expands, a difference between the pressure in the container 5 and the pressure in the void occurs, and the void bursts and scatters to the insulating substrate 1b and other members. May adhere. For this reason, the exhaust time t3 (the “third period” of the present invention) when the pressure in the container 5 is reduced from P3 to P2 can be reduced over time (for example, about 40 to 60 seconds). Preferably, the voids in the solder material can be defoamed without rupturing, and a good soldering quality can be obtained.

  Further, the flow rate adjustment valve 11f provided in the vacuum exhaust device 11 is preferably one that can electrically adjust the opening degree of the valve, but further, a pressure flow region is provided by branching the exhaust pipe and providing a second flow rate adjustment valve. It is good also as a structure which can switch an exhaust speed according to.

(6) Reducing gas introduction When the inside of the container 5 reaches the pressure P2 in the pressure reducing operation of (5) above, the supply valve 9b of the reducing gas supply device 9 is opened and the reducing gas is supplied from the reducing gas cylinder 9c to the container 5. Supply. Thereafter, the supply valve 9b is closed when the pressure inside the container 5 reaches atmospheric pressure.

  This operation has an effect of removing the oxide film in the solder material with the reducing gas because voids are generated by the strong oxide film of the solder when the void in the solder material is defoamed. The voids in the solder material are reduced when the operations (5) and (6) are repeated twice or more, but the effect of reducing the voids is small even when the operations are repeated six times or more.

(7) Cooling (solder solidification)
Heating by the induction heating coil 3a is stopped, and the tray 2 on which the processing target member 1 is placed is lowered by the lifting device 16 so as to contact the cooling plate 3b, and the processing target member 1 is cooled by the cooling plate 3b. The cooling plate 3b is made of a material that is not directly heated, and is in contact with the induction heating coil 3a in which the refrigerant cooled to a predetermined temperature by the refrigerant circulation device 4 is circulated. The member 1 can be quickly cooled.

(8) Introduction of inert gas After the temperature T of the member 1 to be processed is measured by the temperature sensor 13 and reaches the second target cooling temperature T1, the supply valve 9b of the reducing gas supply device 9 is closed, and then the vacuum exhaust device 11 main exhaust valve 11b, slow valve 11g and roughing valve 11d are opened, and the inside of the container 5 is evacuated using a vacuum pump 11h. The main exhaust valve 11b, the slow valve 11g, and the roughing valve 11d are closed when the inside of the container 5 reaches a predetermined degree of vacuum (pressure P1 in the drawing). During this time, the member to be treated 1 is continuously cooled by the cooling plate 3b.

(9) Unloading The lid 5a is lifted by the opening / closing actuator 17 to open the container 5, and after the member 1 is unloaded, the lid 5a is lowered by the opening / closing actuator 17 to close the container 5.

  As described above, according to the heating / cooling device 100 of the present invention, the heat treatment and the cooling treatment can be continuously performed on the member to be treated 1 only by the raising / lowering operation. Can do.

  In addition, the induction heating coil 3a of the induction heating device 3 can heat the base plate 1a, the solder, the metal plate, and the like that are the heated portion of the member to be processed 1 through the tray 2 with high heating efficiency. Further, the cooling plate 3b is stored by a refrigerant circulating inside the pipe of the induction heating coil 3a, and the high-temperature processed member 1 in which the solder is melted is brought into contact with the cooling plate 3b to absorb heat, thereby improving the heating and cooling efficiency. This can increase the processing time.

  In addition, since the container 5 is downsized, the exhaust time and the supply time of the reducing gas and the inert gas can be shortened, and the evacuation operation can be performed in multiple stages according to the pressure region in the container 5. Therefore, it is possible to eliminate the scattering of the solder material of the semiconductor module.

  Next, with reference to FIG. 4A to FIG. 4C, experimental results by the heating / cooling device 100 of the present embodiment will be described.

First, FIG. 4A shows time and pressure change before and after the countermeasure. Before taking countermeasures (conventional), the time taken to evacuate from 1.0 × 10 ⁵ Pa to 1.0 × 10 ² Pa or less was as short as about 19 seconds, so the expanded void in the solder material exploded. As a result, it was scattered on the insulating substrate 1b and the semiconductor element 1c.

However, this time, the time taken to evacuate from 1.0 × 10 ⁵ Pa to 1.0 × 10 ² Pa was extended to 40 seconds or more by the above-described (5) decompression operation. As a result, the following experimental results were obtained.

  FIG. 4B shows the void generation rate in the solder material before and after the countermeasure. Here, the horizontal axis represents the number of times of evacuation (times), and the vertical axis represents the void generation rate (%) under the insulating substrate 1b.

  As shown in FIG. 4B, when the number of times of evacuation was 1 (conventional), the average void generation rate was about 2.8%, whereas the number of times of evacuation was set to 2 (2 cycles). In the case (after countermeasures), the average void generation rate has decreased to about 1.4%. Also, when the number of times of vacuum evacuation was 3 to 5, the average void generation rate was 1.1 to 1.6%, which was lower than that when the number of times of vacuum evacuation was one. That is, a result that the void generation rate can be suppressed by setting the number of times of vacuum evacuation to 2 times or more was obtained.

  FIG. 4C shows the solder scattering rate in the solder material before and after the countermeasure. Here, the horizontal axis represents the evacuation time (seconds) for void removal, and the vertical axis represents the solder scattering rate (%).

  As shown in FIG. 4C, when the evacuation time is about 19 seconds (conventional), the solder scattering rate was about 60%, whereas the evacuation time was 40 seconds or more (after countermeasures). In addition, the solder scattering rate has decreased to around 20%. That is, the solder scattering rate can be suppressed to about 1/3 of the conventional one by the above-described (5) pressure reducing operation.

  As described above, in the heating and cooling apparatus 100, the flow rate adjusting valve 11f for adjusting the exhaust flow rate of the gas is provided on one of the exhaust pipes branched for vacuum exhaust. The control device 6 switches the exhaust pipe based on the pressure in the container 5 and performs vacuum exhaust while changing the exhaust speed. This makes it possible to improve the soldering quality of the member 1 to be processed.

  The heating / cooling apparatus 100 of the present embodiment has been described as an apparatus that heats and cools the processing target member 1 using the induction heating apparatus 3, but the heating source may be formed with a hot plate, a lamp heater, or the like. . By configuring the decompression control method of the vacuum evacuation device 11 to be the same, it is possible to obtain the same effect of reducing voids in the solder material of the semiconductor module and eliminating adhesion of members due to solder scattering.

DESCRIPTION OF SYMBOLS 1 To-be-processed member 1a Base board 1b Insulating substrate 1c Semiconductor element 2 Tray 3 Induction heating apparatus (heating-cooling means)
3a Induction heating coil 3b Cooling plate 3c Support plate 3d Insulating cover 3e Spacer 4 Refrigerant circulation device 4a Heat exchanger 4b Circulation pump 4c, 4d Refrigerant piping 5 Container 5a Lid 5b Bottom plate 5c Sealing material 5d Heat shield cover 6 Control device (control means) )
7 Input device 9 Reducing gas supply device (reducing gas supply means)
9a Supply pipe 9b Supply valve 9c Reducing gas cylinder 10 Inert gas supply device (inert gas supply means)
10a supply pipe 10b supply valve 10c inert gas cylinder 11 vacuum exhaust device (vacuum exhaust means)
11a Main exhaust pipe 11b Main exhaust valve 11c Rough exhaust pipe 11d Rough exhaust valve 11e Slow exhaust pipe 11f Flow rate adjusting valve (flow rate adjusting means)
11g Slow valve 11h Vacuum pump 13 Temperature sensor 14 Pressure sensor 16 Lifting device 16a Lifting actuator 16b Lifting base 16c Lifting shaft 16d Lifting shaft 16e Base 16f Support plate 17 Opening / closing actuator 18 Shaft 19 Pressure gauge 21 Release valve 22 Release pipe 100 Heating / cooling device

Claims (3)

An airtight container having an opening / closing mechanism capable of taking in and out the member to be processed;
A heating / cooling means for heating or cooling the member to be treated;
A temperature sensor for measuring the temperature of the member to be processed;
A pressure sensor for detecting the pressure in the container;
Reducing gas supply means for supplying a reducing gas into the container;
An inert gas supply means for supplying an inert gas into the container;
A vacuum exhaust means for decompressing the inside of the container;
In a heating and cooling apparatus comprising a control means for controlling heating or cooling by the heating and cooling means and a pressure in the container based on the temperature measured by the temperature sensor,
The vacuum evacuation means branches a flow path of an exhaust pipe to which a vacuum pump for exhausting the gas in the container is connected, and adjusts the flow rate of the gas to at least one of the branched exhaust pipes Providing means,
The heating and cooling apparatus, wherein the control means switches the branched exhaust pipe based on the pressure in the container and changes the vacuum exhaust speed in multiple stages. The control means includes
In the first period until the pressure in the container changes from atmospheric pressure to a preset first pressure, the exhaust pipe provided with the flow rate adjusting means is switched to perform evacuation,
In the second period until the pressure in the container reaches the second pressure set in advance from the first pressure, the exhaust pipe not provided with the flow rate adjusting means is switched to perform vacuum exhaust,
The vacuum exhaust is performed by switching to the exhaust pipe provided with the flow rate adjusting unit again during the third period until the pressure in the container reaches the third pressure set in advance from the second pressure. Item 2. The heating and cooling device according to Item 1. The vacuum evacuation means branches the flow path of the exhaust pipe connected to the vacuum pump into two or more, and is provided with flow rate adjusting means having different conductances in the branched exhaust pipes,
The heating / cooling apparatus according to claim 1 or 2, wherein the control means performs vacuum exhaust so that a predetermined pressure is obtained at an exhaust speed corresponding to each step.

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