JP6295564B2 - Vacuum apparatus, vacuum processing method, and electronic device - Google Patents

Description

  The present invention relates to a vacuum apparatus, a vacuum processing method, and an electronic device formed by the vacuum processing method capable of performing a heat treatment on an electronic device while maintaining a vacuum state in a vacuum container.

  An electronic device in which electronic components such as an infrared sensor, a gyro sensor, a temperature sensor, a pressure sensor, and an acceleration sensor are vacuum-sealed in a package has been put into practical use. For example, an infrared sensor sealing package used for a nighttime security monitoring camera or a thermography for calculating and displaying a temperature distribution is formed by sealing an infrared sensor in a package with a high degree of vacuum.

  An electronic device such as an infrared sensor sealed package heats an electronic component in a vacuum vessel and vacuum seals the package. A technique for vacuum-sealing an electronic component in a package is disclosed in, for example, Patent Document 1.

WO2010 / 095367

  However, when heat treatment is performed on electronic components while maintaining a vacuum state in the vacuum vessel, the temperature of the vacuum vessel becomes high, and water vapor and oxygen adhering to the inner surface of the vacuum vessel are released into the vacuum vessel. It takes a long time to reach the target vacuum.

  The present invention has been made in view of the above-described problems. Even when heat treatment is performed on an electronic component while maintaining a vacuum state in a vacuum vessel, the target vacuum degree is quickly reached and the electrons are reached. An object of the present invention is to provide a vacuum apparatus, a vacuum processing method, and an electronic device formed by the vacuum processing method, which can heat-process components.

  In order to achieve the above object, a vacuum apparatus according to the present invention includes a vacuum container having a substrate fixed therein, a plurality of heating elements disposed on the outer periphery of the vacuum container, a vacuum pump for evacuating the vacuum container, Control means for controlling the plurality of heating elements such that the substrate is maintained at the temperature Tp. Here, the control means holds the plurality of heating elements at the temperature T1 in the first period, and sets the heating elements separated from the substrate by a predetermined distance or more in the second period to a temperature T2 lower than the temperature T1. At the same time, the other heating element is set to temperature T3.

  In order to achieve the above object, a vacuum processing method according to the present invention is a vacuum processing method using a vacuum apparatus having a vacuum vessel in which a plurality of heating elements are arranged on the outer periphery and a substrate is fixed inside. The vacuum vessel is operated in a state where the object to be processed is disposed on the substrate, and the plurality of heating elements are maintained at the temperature T1 so that the substrate is maintained at the temperature Tp in the first period. In order to maintain the substrate at the temperature Tp during the period, the heating element that is separated from the substrate by a predetermined distance or more is set to a temperature T2 that is lower than the temperature T1, and the other heating elements are set to the temperature T3. When the target value is reached, the other heating elements are held at the temperature T4 and the object to be processed is processed so that the substrate is maintained at the temperature Tq higher than the temperature Tp.

  In order to achieve the above object, an electronic device according to the present invention has an electronic component and a package placed on a substrate of a vacuum vessel as objects to be processed, and the electronic component is vacuum sealed in the package by the vacuum processing method described above. Formed.

  According to the above-described aspect of the present invention, even when heat treatment is performed on an electronic component while maintaining a vacuum state in the vacuum vessel, the electronic component can be heat-treated by quickly reaching a target degree of vacuum. .

It is the figure which showed the time-dependent change of (a) sectional drawing of the vacuum apparatus 10 which concerns on 1st Embodiment, and (b) vacuum degree and temperature. It is sectional drawing of the vacuum apparatus 100 which concerns on 2nd Embodiment. It is the figure which showed the time-dependent change of the vacuum degree of the vacuum apparatus 100 which concerns on 2nd Embodiment, and temperature. It is the figure which showed the time-dependent change of the vacuum degree at the time of performing the same control with respect to a heat generating body. It is sectional drawing of the vacuum apparatus 100 by which the 2nd heat generating body group 320 was arrange | positioned so that attachment or detachment was possible. It is sectional drawing of the vacuum apparatus 100B which concerns on 3rd Embodiment.

(First embodiment)
A first embodiment of the present invention will be described. A cross-sectional view of the vacuum apparatus according to the present embodiment is shown in FIG. 1A, the vacuum apparatus 10 includes a vacuum container 20, a plurality of heating elements 30, a vacuum pump 40, and a control means 50.

  The vacuum vessel 20 has a plurality of heating elements 30 arranged on the outer periphery and a substrate 21 fixed to the inside. A vacuum pump 40 is connected to one end of the vacuum vessel 20, and the internal air is evacuated by the vacuum pump 40. Here, as shown in FIG. 1A, a heating element 30 within a predetermined distance l from the substrate 21 is a heating element 30a, and the other heating elements 30 are heating elements 30b.

  The control means 50 controls the plurality of heating elements 30 based on the degree of vacuum of the vacuum container 20 and the temperature of the substrate 21. Specifically, the control unit 50 controls the heating element 30 so that the substrate 21 is maintained at the temperature Tp.

  The operation of the control means 50 will be described in detail with reference to FIG. In FIG. 1B, the solid line indicates the degree of vacuum of the vacuum container 20, the dotted line indicates the temperature of the substrate 21, the alternate long and short dash line indicates the control temperature of the heating element 30a within a predetermined distance l from the substrate 21, and the alternate long and two short dashes line indicates other heat generation. This is the control temperature of the body 30b.

  1 (a) and 1 (b), the control means 50 starts the evacuation by the vacuum pump 40 in a state in which an object to be processed (not shown) is arranged on the substrate 21, and then the substrate in the first period. The heating element 30 is held at the temperature T1 so that 21 is maintained at the temperature Tp. For example, the control means 50 keeps the heating element 30 at a high temperature of about 300 ° C., whereby the temperature of the vacuum container 20 rises, and water vapor, oxygen, etc. adhering in the vacuum container 20 are used as the discharge gas in the vacuum container. Then, the discharged gas is discharged to the outside of the vacuum container 20 by the vacuum pump 40.

  Then, when the rate of decrease in the degree of vacuum of the vacuum container 20 becomes smaller than a predetermined threshold in the first period, the control means 50 determines that the second period has been entered, and the substrate 21 is maintained at the temperature Tp. As described above, the heating element 30b whose distance from the substrate 21 is larger than the distance l is changed to the temperature T2 smaller than the temperature T1, and the heating element 30a whose distance from the substrate 21 is within the distance l is raised to the temperature T3.

  That is, when the vacuum degree becomes dull as the vacuum pump 40 approaches the capacity limit, the temperature of the heating element 30a in the vicinity of the substrate 21 is increased, while the temperature of the other heating elements 30b is decreased. 21 is maintained at temperature Tp. As a result, the temperature of the vacuum container 20 is lowered, the generation of released gas is suppressed, and the degree of vacuum is lowered again.

  Then, the control means 50 determines that the third period has been entered when the vacuum degree of the vacuum vessel 20 has reached the target degree of vacuum Pt in the second period. In the third period, the control means 50 raises the heating element 30a from the temperature T3 to the temperature T4 so that the temperature of the substrate 21 is maintained at the processing temperature Tq (> Tp). Then, in a state where the temperature of the substrate 21 is maintained at the processing temperature Tq, a process such as vacuum sealing is performed on the target object disposed on the substrate 21.

  As described above, the vacuum apparatus 10 according to the present embodiment operates all the heating elements 30 in the first period to quickly reduce the degree of vacuum. When the rate of decrease in the degree of vacuum becomes smaller than a predetermined threshold, the vacuum apparatus 10 decreases the temperature of the heating element 30b away from the substrate 21 while increasing the temperature of the heating element 30a in the vicinity of the substrate 21. Thus, the vacuum degree can be lowered by lowering the temperature of the vacuum container 20 while maintaining the temperature of the substrate 21 at the temperature Tp.

  Therefore, the vacuum apparatus 10 according to the present embodiment promptly reaches the target degree of vacuum even when processing the object to be processed while maintaining the vacuum state in the vacuum container 20, The body can be processed.

(Second Embodiment)
A second embodiment will be described. A sectional view of the vacuum apparatus according to the present embodiment is shown in FIG. 2, the vacuum device 100 includes a vacuum vessel 200, eight heating elements 300a to 300h, a vacuum pump 400, and a control unit 500 (not shown in FIG. 2).

  The vacuum container 200 is a hollow container formed in a long cylindrical shape, and a plate 210 for placing an electronic device is fixed inside by welding or a screw.

  For example, a cartridge heater formed in a rod shape can be applied to the heating element 300, and the temperature is controlled independently of each other. As the heating element 300, for example, a cartridge heater, a ceramic heater, a nichrome wire, or the like can be applied.

  In the present embodiment, eight heating elements 300a to 300h are fixed on the outer periphery of the vacuum vessel 200 at equal intervals. The heating element 300a is fixed so as to be positioned directly above the plate 210 fixed inside the vacuum vessel 200, and the heating element 300e is fixed so as to be positioned directly below the plate 210. Further, the heating elements 300d and 300f are positioned obliquely below the plate 210 so that the heating elements 300b and 300h are positioned obliquely above the plate 210 so that the heating elements 300c and 300g are positioned almost directly beside the plate 210. As described above, each is fixed on the outer periphery of the vacuum vessel 200.

  Hereinafter, a heating element group located near the plate 210 is defined as a first heating element group 310, and a heating element group located at a position away from the plate 210 is defined as a second heating element group 320. To do. In the present embodiment, the first heating element group 310 is configured by heating elements 300c, 300d, 300f, and 300g, and the second heating element group 320 is configured by heating elements 300a, 300b, 300e, and 300h.

  The vacuum pump 400 is disposed at one end of the vacuum vessel 200 and evacuates the air in the vacuum vessel 200. As the vacuum pump 400, for example, a rotary pump, a dry pump, an oil diffusion pump, a turbo molecular pump, an ion pump, a cryopump, or the like can be applied.

  The control unit 500 (not shown) controls the heating element 300 and the vacuum pump 400. The controller 500 according to the present embodiment controls the first heating element group 310 and the second heating element group 320 independently of each other. Hereinafter, the operation and function of the controller 500 will be described in detail with reference to FIG.

  FIG. 3 is a graph showing changes with time in the degree of vacuum and temperature. The solid line is the degree of vacuum in the vacuum container 200, the dotted line is the temperature of the plate 210, the alternate long and short dash line is the control temperature of the first heating element group 310, and the alternate long and two short dashes line is the control temperature of the second heating element group 320.

  The control unit 500 starts the evacuation of the vacuum container 200 by operating the vacuum pump 400 in a state where the electronic device A to be processed is arranged on the plate 210, and simultaneously, the first heating element group 310 (heat generation) Body 300c, 300d, 300f, 300g) and second heating element group 320 (heating elements 300a, 300b, 300e, 300h) are raised.

  By operating the vacuum pump 400 in a state where the heating element 300 is heated and controlled, the temperature of the vacuum container 200 rises, and accordingly, gas molecules are released from the inner surface of the vacuum container 200, and the vacuum pump 400 causes the vacuum container 200. It is discharged outside. That is, the degree of vacuum of the vacuum container 200 decreases. At the start of evacuation, the control unit 500 controls the heating of all the heating elements 300a to 300h to quickly increase the temperature of the vacuum container 210 and release / exclude gas molecules all at once. Decrease the degree quickly.

  The controller 500 keeps the temperature of the heating elements 300a to 300h constant when the temperature of the plate 210 reaches the standby temperature Tp. In the present embodiment, the controller 500 maintains the heating elements 300a to 300h at the temperature T1. Thereby, the temperature of the plate 210 is maintained at the standby temperature Tp, and the vacuum vessel 210 is also maintained at a constant temperature. In a state where the temperature of the vacuum vessel 210 is constant, the amount of gas molecules released from the inner surface of the vacuum vessel 200 is also constant, and the rate of decrease in the degree of vacuum of the vacuum vessel 200 is gradually reduced. Then, by reaching the limit of the exhaust capacity of the vacuum pump 210 at time t1, the degree of vacuum becomes a constant value (Ps).

  When the degree of vacuum of the vacuum pump 210 reaches a constant value (Ps) (time t1), the controller 500 controls the second heating element group 320 (heating elements 300a and 300b) located at a position away from the plate 210. , 300e, 300h) is stopped, and the first heating element group 310 (heating elements 300c, 300c,. 300d, 300f, and 300g) are heated and controlled.

  The second heating element group 320 gradually decreases to the initial temperature T0 when the heating control is stopped. Here, in this embodiment, the initial temperature T0 corresponds to the temperature T2 in the claims. On the other hand, since the first heating element group 310 is located near the plate 210, the temperature of the plate 210 can be maintained at the standby temperature Tp without increasing the temperature so much. Therefore, the temperature of the vacuum vessel 200 gradually decreases. As the temperature of the vacuum container 200 decreases, the amount of gas molecules released from the inner surface of the vacuum container 200 decreases, and the degree of vacuum of the vacuum container 200 begins to decrease again.

  When the temperature of the second heating element group 320 decreases to the initial temperature T0 (time t2), the control unit 500 maintains the first heating element group 310 at the temperature T3 at that time.

  When the degree of vacuum of the vacuum container 200 reaches the target degree of vacuum Pt (time t3), the controller 500 raises the temperature of the plate 210 by raising the temperature of the first heating element group 310 to the temperature T4. The temperature is raised to the working temperature Tq, and the electronic device A previously disposed on the plate 210 is heated. When the heating process for the electronic device A is completed (time t4), the control unit 500 stops the heating control for the first heating element group 310. As a result, the temperature of the vacuum container 200 decreases, and the degree of vacuum of the vacuum container 200 decreases. From the results of the experiment, when “Tp = 200 ° C., Tq = 250 ° C.”, the most effective result when “T1 = 300 ° C., T3 = 330 ° C., T4 = 350 ° C.” in the above configuration. Could get.

  Here, for comparison, FIG. 4 shows a graph showing changes in the degree of vacuum and temperature with time when the controller 500 ′ controls the temperature of all the eight heating elements 300 to 300 h in the same manner. As in FIG. 3, the degree of vacuum in the vacuum vessel 200 is indicated by a solid line, and the temperature of the plate 210 is indicated by a dotted line. In addition, the control temperatures of the eight heating elements 300 to 300h are indicated by alternate long and short dash lines.

  As shown in FIG. 4, the controller 500 ′ operates the vacuum pump 400 to start evacuation of the vacuum vessel 200, and at the same time, raises the eight heating elements 300 to 300 h to the temperature T 1, The temperature is maintained at the standby temperature Tp. As a result, as in FIG. 3, gas molecules are released / excluded at once from the inner surface of the vacuum vessel 200, and the vacuum degree of the vacuum vessel 200 is quickly reduced. Thereafter, when the limit of the exhaust capacity of the vacuum pump 210 is reached, the degree of vacuum does not drop much from the limit value. When the eight heating elements 300a to 300h are maintained as they are at the temperature T1, the degree of vacuum of the vacuum container 200 is not greatly improved.

  When the vacuum degree of the vacuum container 200 reaches the target vacuum degree P′t (time t5), the control unit 500 ′ increases the temperature of the eight heating elements 300 to 300h to the temperature T′4. The temperature of the plate 210 is raised to the working temperature Tq, and the electronic device A previously disposed on the plate 210 is heated.

  As can be seen from FIG. 4, when all the eight heating elements 300a to 300h are controlled to be heated in the same manner, a sufficient degree of vacuum cannot be obtained, and the heating elements 300a to 300h are used for a long time until the target degree of vacuum is reached. And the vacuum pump 400 needs to be operated, and the productivity is poor.

  Compared to this, the vacuum apparatus 100 according to the present embodiment is located away from the plate 210 when the decrease in the vacuum degree is small after the heating degree of all the heating elements 300a to 300h is controlled to quickly reduce the vacuum degree. The heating control to the second heating element group 320 located at the position is stopped, and only the first heating element group 310 located near the plate 210 is operated. By operating only the heating element 300 located near the plate 210, the temperature of the plate 210 can be efficiently maintained at the temperature Tp, and the heat generation cost can be reduced, and the temperature of the vacuum vessel 200 is decreased. Thus, the amount of gas molecules released from the vacuum vessel 200 is reduced, and the vacuum degree of the vacuum vessel 200 can be lowered to the target vacuum degree Pt.

  Therefore, the vacuum apparatus 100 according to the present embodiment quickly reaches the target degree of vacuum even when the electronic device A is subjected to heat treatment while maintaining the vacuum state in the vacuum container 200, and the electronic device A can be heat-treated.

  In the above-described embodiment, all the eight heating elements 300a to 300h are fixed on the outer periphery of the vacuum vessel 200, but the present invention is not limited to this. For example, the second heating element group 320 (heating elements 300a, 300b, 300e, 300h) used only for lowering the degree of vacuum can be detachably disposed on the outer periphery of the vacuum vessel 200. FIG. 5 shows a cross-sectional view when the second heating element group 320 is detachably disposed on the outer periphery of the vacuum vessel 200.

  In this case, when the degree of vacuum of the vacuum pump 210 reaches a constant value (Ps) (time t1 in FIG. 3), the controller 500 drives a motor, an air cylinder, or the like not shown in FIG. The first heating element group 310 (heating elements 300c, 300d) is removed so that the body group 320 (heating elements 300a, 300b, 300e, 300h) is removed from the vacuum vessel 200 and the temperature of the plate 210 is maintained at the standby temperature Tp. , 300f, 300g). The operation after the first heating element group 310 is held at the temperature T3 is the same as the operation described above with reference to FIG.

  The second heating element group 320 located at a position away from the plate 210 is detachably disposed, and the second heating element group 320 is removed from the vacuum vessel 200 when the degree of vacuum reaches a certain value (Ps). In this case, the temperature of the vacuum container 200 is rapidly reduced as compared with the case where the heating control to the second heat generator group 320 is stopped in a state where the second heat generator group 320 is arranged on the vacuum container 200. be able to. Accordingly, the amount of gas molecules released from the inner surface of the vacuum container 200 is quickly reduced, and the vacuum degree of the vacuum container 200 reaches the target vacuum degree Pt in a short time.

(Third embodiment)
A third embodiment will be described. A sectional view of the vacuum apparatus according to this embodiment is shown in FIG. In FIG. 6, the vacuum device 100B includes a vacuum vessel 200B, eight heating elements 300Ba-300Bh, a vacuum pump 400B, six cooling pipes 600Ba-600Bf, and a control unit 500B (not shown).

  The vacuum apparatus 100B according to the present embodiment is formed by further disposing six cooling pipes 600Ba-600Bf on the outer periphery of the vacuum vessel 200 of FIG. 2 described in the second embodiment.

  The cooling pipe 600B is a pipe through which water and air flow, and the vacuum container 200B is cooled by flowing water and air through the cooling pipe 600B. In the present embodiment, the cooling pipes 600B are alternately arranged with the heating elements 300B in a region away from the plate 210B on the outer periphery of the vacuum vessel 200B. Specifically, the cooling pipe 600B is not disposed between the heating elements 300Bc-300Bd and between the heating elements 300Bf-300Bg, which are close to the plate 210B.

  The operation of the vacuum device 100B will be described. Similar to the vacuum apparatus 100 described in the second embodiment, the control unit 500B operates the vacuum pump 400B to evacuate the vacuum container 200B in a state where the electronic device A to be processed is disposed on the plate 210B. The heating element 300Ba-300Bh is raised to the temperature T1. Thereby, the vacuum degree of the vacuum container 200B falls rapidly.

  When the exhaust capacity of the vacuum pump 210B reaches the limit while the heating elements 300Ba-300Bh are maintained at the temperature T1, the control unit 500B includes the heating elements 300Ba disposed away from the plate 210B, The temperature of the plate 210B is maintained at the temperature Tp by stopping the heating control to 300Bb, 300Be, and 300Bh and increasing the temperature of the heating elements 300Bc, 300Bd, 300Bf, and 300Bg arranged near the plate 210B to T3. To do. At this time, the controller 500B further starts inflow of water or air into the six cooling pipes 600Ba-600Bf to start forced cooling of the vacuum vessel 200B.

  Thereby, the temperature of the vacuum vessel 200B can be sufficiently lowered while maintaining the temperature of the plate 210B at the temperature Tp. As the temperature of the vacuum container 200B decreases, the degree of vacuum of the vacuum container 200B also decreases.

  When the degree of vacuum of the vacuum vessel 200B reaches the target degree of vacuum Pt, the controller 500B raises the temperature of the plate 210B by raising the heating elements 300Bc, 300Bd, 300Bf, 300Bg located near the plate 210B. The temperature is raised to the working temperature Tq, and the electronic device A disposed on the plate 210B is heated. The controller 500B stops the heating control of the heating elements 300Bc, 300Bd, 300Bf, 300Bg and stops the inflow of water or air into the cooling pipes 600Ba-600Bf after the heating process for the electronic device A is completed.

  As described above, the vacuum apparatus 100B according to the present embodiment is disposed at a position away from the plate 210B even when the electronic device A is heat-treated while maintaining the vacuum state in the vacuum container 200B. In parallel with stopping the heating control to the heating element 300B, the vacuum vessel 200B is forcibly cooled by the cooling pipe 600B, so that the electronic device A is heated by quickly reaching the target vacuum level. be able to.

  The vacuum apparatus according to the present invention can be applied to a process that requires heat treatment in vacuum, and in particular, can be applied to a process of vacuum-sealing an infrared package. Note that the present invention is not limited to the above-described embodiment, and any design change or the like within a range not departing from the gist of the present invention is included in the present invention.

DESCRIPTION OF SYMBOLS 10 Vacuum apparatus 20 Vacuum container 21 Substrate 30 Heating element 40 Vacuum pump 50 Control means 100, 100B Vacuum apparatus 200, 200B Vacuum container 210, 210B Plate 300, 300B Heating element 400, 400B Vacuum pump 500, 500B Control part 600B Cooling tube

Claims (7)

A vacuum vessel with a substrate fixed inside,
A plurality of heating elements arranged on the outer periphery of the vacuum vessel;
A vacuum pump for evacuating the vacuum vessel;
Control means for controlling the plurality of heating elements such that the substrate is maintained at a temperature Tp;
With
The control means holds the plurality of heating elements at a temperature T1 in a first period, and sets a heating element that is more than a predetermined distance away from the substrate to a temperature T2 lower than the temperature T1 in a second period. A vacuum apparatus characterized in that the other heating element is set to a temperature T3. 2. The vacuum apparatus according to claim 1, wherein, in the second period, the control unit separates the heating element separated from the substrate by a predetermined distance or more from the outer periphery of the vacuum vessel instead of setting the temperature T <b> 2. The control means has a function of monitoring the degree of vacuum of the vacuum container,
The control means determines that the second period has been entered when the rate of decrease in the vacuum degree is smaller than a predetermined threshold in the first period.
The vacuum apparatus according to claim 1 or 2. The control means holds the other heating element at a temperature T4 so that the substrate is maintained at a temperature Tq higher than the temperature Tp when the degree of vacuum reaches a target value in the second period. Item 4. The vacuum device according to Item 3. A cooling means disposed on the outer periphery of the vacuum vessel, and cooling the vacuum vessel during operation;
The control means does not operate the cooling means in the first period and operates the cooling means in the second period;
The vacuum apparatus of any one of Claims 1 thru | or 4. A vacuum processing method using a vacuum device provided with a vacuum vessel in which a plurality of heating elements are arranged on the outer periphery and a substrate is fixed inside,
The vacuum vessel is operated in a state where the object to be processed is disposed on the substrate,
In the first period, the plurality of heating elements are held at a temperature T1 so that the substrate is maintained at a temperature Tp.
In the second period, the heating element separated from the substrate by a predetermined distance or more is set to a temperature T2 lower than the temperature T1 and the other heating elements are set to a temperature T3 so that the substrate is maintained at the temperature Tp.
When the degree of vacuum of the vacuum container reaches a target value, the other heating elements are held at the temperature T4 and the object to be processed is processed so that the substrate is maintained at a temperature Tq higher than the temperature Tp. ,
Vacuum processing method. The vacuum processing method according to claim 6, wherein, in the second period, the heating element separated from the substrate by a predetermined distance or more is separated from the outer periphery of the vacuum vessel instead of being set to a temperature T2 lower than the temperature T1.

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