JP2755340B2 - Radiation control system and radiation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation control system and a radiation control method, and more particularly to a system and a method for automatically controlling a radiation device, wherein a solvent is evaporated by microwave radiation and then precursored by microwave radiation. It is suitable for application when applying microwave radiation to physical processes and chemical reactions, such as when a substance is imidized to obtain a polyimide polymer from a polyamic acid precursor dissolved in a solvent. This system is a computer control system. Further, the present invention applies microwave radiation to the precursor to automatically control the rate and degree of imidization, and to terminate the degree of imidization by in situ non-destructive testing without operator intervention. An automatic method and system for accurately determining

[0002]

2. Description of the Related Art In the manufacture of integrated circuits such as microcircuits, an insulating layer is provided over the circuit or is used to form a San-Germanic structure. These insulating layers may include a polyimide film. Conventional polyimides used in this way are made from precursors containing polyamic acid groups, polyamide ester groups, or combinations thereof. This precursor is dianhydride (d
It is made by the reaction of ianhydride and diamine or the reaction of diester-diacid dichloride and diamine. The resulting precursor is soluble in common organic solvents and can be dissolved and applied as a coating to various substrates. After coating the substrate, the coated substrate is stripped of solvent, usually by applying heat, and further heated to convert the precursor to a polyimide film. This imidization reaction involves the release of water or alcohol as a product. The obtained polyimide film is not easily dissolved in a conventional solvent, is extremely strong, has excellent high-temperature characteristics, and can be adhered to most substrates. Due to their outstanding physical properties, polyimide resins are widely used in coating applications. One of the disadvantages of polyimides in the above reactions is that they require a long cure time to achieve their final mechanical properties, which can generally be as long as 10 to 12 hours for thin films. .

As mentioned above, this precursor is converted to polyimide by releasing water or alcohol as a by-product of the reaction. Usually this imidation starts at about 150 ° C,
This process, which is sometimes referred to as dehydration, requires a temperature of about 300 ° C to complete, and a temperature of 400 ° C to complete some polyimide ordering processes. .

In curing the polyamic acid by this dehydration treatment to form the polyimide resin, care must be taken to ensure uniform heating over the entire cross section of the polyamic acid being converted, which can be easily achieved at any time. is not. For example, if the polyamic acid film is heated in a conventional furnace, the film will cure from its outermost surface toward the interior, and if the curing process proceeds too quickly, the exterior of the film will have (1) a center. May cure much faster than the part, resulting in voids, and (2) degrading mechanical properties such as reduced modulus, expansion, solvent absorption and enhanced CTE (coefficient of thermal expansion). become.

The prior art includes general disclosures about using microwave radiation to convert a polyamic acid precursor to a polyimide (US Pat. No. 4,30,30).
5,796 and U.S. Pat.No. 4,439,381 and U.S. Pat.
No. 4,681,654), however, has not been achieved in practice to convert more than 50% of the precursor to polyimide.

[0006]

It is believed that the problems encountered in the microwave curing of polyamic acids to polyimides are largely due to the microwave equipment used. Microwave devices conventionally used in this connection are similar in operation to "household microwave ovens", i.e. have one or more magnetrons that couple the microwave radiation into a chamber. It is a big multi-mode chamber. Generally, these systems operate at full power and are adjusted by turning them on and off, thus providing a form of "pulsed" radiation treatment. This apparatus has disadvantages such as non-uniform microwave fields that vary spatially with movement and / or partial curing and difficulty in controlling the rate of evaporation and curing. This can cause non-uniform curing at the microscopic level, and the material shrinks upon curing, thus increasing local distortion in the film. Further, it is difficult to control the evaporation of the solvent, so that the quality of the film is inferior. In such a configuration, it is not possible to obtain a sufficiently high electric field strength (power density) to obtain a complete or almost complete cure of the polyimide. Have difficulty. The above-mentioned US Pat. Nos. 4,305,796 and 4,439,381 describe in this regard the use of short bursts of microwave radiation.

[0007] Thus, prior art solutions to the difficulties encountered with microwave curing use microwave treatment for the partial imidization of polyamic acid to polyimide, after which the resulting product is microwaved. It is heated by means other than radiation.

One of the other difficulties encountered in the prior art is the inability to use in-situ natural means of testing to determine the degree of imidization of polyamic acid to polyimide. The product is removed from the imidation reaction environment and tested by wet analysis or other test methods such as FTIR spectroscopy and the like to identify carboxylic acid groups in the product. It must be.

Also, these prior art methods using microwave radiation precisely control the rate and extent of polyimidic acid to polyimide imidization over a range from partial imidization to almost complete imidization. This is not useful for optimizing the mechanical properties of the imidized product.

Also, a polyimide precursor is provided on a substrate such as a metal covering Kapton® polyimide and various metal oxides or metal-containing PC boards such as alumina with metal wiring and metal pads. At times, it is not disclosed in prior art methods of exposing this polyimide precursor material to microwave radiation. It is generally considered that an arc is created between the metal pads, harming the pads and the dielectric material.

[0011] In the apparatus of the present invention, the workpiece is held in a single mode microwave applicator. This microwave applicator is hereinafter referred to as a cavity. As a result of the application of the radiation, the physical properties of the workpiece change, but remain tuned by minimizing the reflected microwave power. The progress of the temperature of the workpiece versus time is monitored and controlled by controlling the radiation intensity so as to meet a predetermined schedule.

In the apparatus of the present invention, the progress of the temperature versus time of the workpiece in the cavity is monitored and controlled according to a predetermined schedule by controlling the radiation intensity while applying the radiation. As a result, the physical properties of the workpiece will then change, but at the same time changing the position of the radiation source and the cavity shot relative to the workpiece will keep that same cavity in tune. The cavity Q is monitored to determine from the temperature-Q history when the workpiece has reached a predetermined physical state and to determine when to stop applying radiation. Prior art methods control these types of procedures manually, and at best provide only partially automated controls.
The present invention provides a fully automated control process.

The method disclosed in US Pat. No. 4,324,965 automates the movement of a triple stub tuner in a waveguide and moves the two stubs at different speeds simultaneously. In comparison, the present invention is a significant improvement by moving the two axes independently at independent speeds and at independent distances.

US Pat. No. 4,667,076 describes an apparatus for annealing silicon wafers, which includes elements for controlling the temperature and gaseous environment. There is no need to tune the chamber because it uses a wide discharge horn.
No teaching or suggestion is made regarding endpoint detection.

US Pat. No. 4,760,228 describes microwave heating, albeit delivered from an extruder, but there is no built-in control element. The reflected power is minimized by the system design but cannot be controlled. The temperature is adjusted to a steady state by fixing the microwave power to a predetermined value.

Accordingly, it is an object of the present invention to provide a fully automatic system for applying radiation to a workpiece to determine when a workpiece has reached a predetermined physical state and to apply the radiation. Automatically determine when to stop.

[0017]

According to the present invention, there is provided a system for controlling the application of radiation to a workpiece within a cavity, comprising: a time tracking means for tracking a current time; Means for receiving a forward power signal indicative of the applied intensity of the radiation, means for receiving a reflected power signal indicative of the reflected intensity of the radiation, means for receiving a temperature signal indicative of the temperature of the workpiece, and reflected intensity / forward. Α given by the intensity is smaller than a predetermined α value, α minimizing means adapted so that the current value of α corresponds to the current time, and by generating an intensity signal indicating the intensity of the radiation Temperature control means for controlling the temperature to be substantially equal to a predetermined temperature; Means for confirming the current value of the workpiece; determining whether or not the workpiece has reached a predetermined physical state from the current value of Q and the current value of the temperature; Means for generating an end signal for terminating the operation of the system when the predetermined final physical state is reached.

[0018]

SUMMARY OF THE INVENTION A feature of the present invention is a system for maintaining the cavity containing a workpiece in resonance, while the physical parameters of the workpiece change with exposure to radiation. A more particular feature of the present invention is a system for applying radiation to a workpiece in a cavity. The system includes means for generating a first signal indicative of the Q of the cavity, means for generating a second signal indicative of the intensity of radiation applied to the workpiece, and a third means indicative of a rate of change of the temperature of the workpiece. Means for generating a signal indicative of the value of the radiation intensity in the cavity in response to the first, second, third and fourth signals, and means for maintaining the cavity in resonance. Have.

In another more particular aspect of the present invention, the first, second, third and fourth signals are signals in a computer, and the computer responds to these signals by radiating intensity within the cavity. And generates a signal that maintains the cavity in resonance.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

For convenience, the use of the present invention in the case of curing a polyamic acid into a polyimide will be mainly described.
However, the invention is not limited to such use. The present invention involves applying microwave radiation in a controlled manner to physical processes and chemical reactions to obtain near defect-free products from these processes in a minimum amount of time.

The frequency of the microwave radiation is selected so that it is absorbed by the sample, and the electric field strength E is empirically determined so that the product obtained when irradiated with the electric field strength E has optimal properties. A choice is made between the determined minimum (Emin) and maximum (Emax). This method can be applied to physical processes such as sample drying such as solvent removal from polyimide precursors or water removal from ceramic raw materials, or chemical processes such as imidization of polyimide precursors and curing of ceramic raw materials. it can.

The present invention also provides a tunable microwave whose microwave output varies with time based on a cure quality factor "Z" (defined below) to obtain a substantially defect free product in a minimum amount of time. It involves applying microwave radiation to such physical processes and chemical reactions within the cavity. Z factor or cure fraction refers to the completion or cure quality of a reaction, such as a physical process or chemical reaction, to which the present invention applies.

The application of microwave radiation to a physical process or chemical reaction provides a cure quality factor, ie, a predetermined value for Z. In a tunable microwave cavity, Z is a function of the Q factor (also called the quality factor) and the temperature of the system. The Q factor is based on the absorption of microwave radiation applied to the process and is measured by comparing the applied and reflected microwave powers in the system at several frequencies, ie, at various heights of the cavity. The Q factor also relates to the dielectric loss factor for the workpiece in the cavity. Generally, the Q factor is calculated from the frequency sweep of the resonant cavity by taking the ratio of the resonant frequency to the width at half the height of the resonance. There is also a method of changing the height of the cavity using a constant frequency. Q
The latter method is generally used to check the value called a factor. In the simplest form, the reflected microwave output of a preselected amount, for example, 30% of the forward output, is calculated from the resonance point. Check using the width of the tuning dip to the point where it occurs. The reflected microwave power is minimized (ie, the maximum amount of microwave power is transmitted into the cavity, thereby being absorbed by the dried and cured sample;
If the minimum amount of microwave power is reflected by the system), the system is said to be in critical coupling or resonance, which is the desired state.
Because the Q factor changes with changes in the physical state of the system and with temperature (ie, the dielectric constant changes due to chemical and / or physical changes), the Q factor itself is itself a chemical or physical reaction. It does not provide a sufficient basis for maximizing results from the application of microwave radiation to dynamic processes. Thus, the present invention uses the system Z, which is a function of the system temperature and Q factor, to provide an indication of how to change the microwave power over time (based on Z). Produces a product that has been processed accurately to a predetermined extent within a minimum amount of time. Thus, the microwave power varies over time based on Z in such a way as to be able to produce a substantially defect-free material in a minimum amount of time, and can be a physical process (eg, drying or solvent removal) or a chemical process (eg, This output is applied within the polymerization or curing of the ceramic material).

With respect to this system (based on a microwave device such as a cavity, a substrate on which the precursor is loaded, and a precursor and / or polyimide depending on the degree of imidization)
Factors are identified and combined with the sample temperature to indicate when the precursor is almost completely imidized or when some degree of partial imidization has been reached. Thus, the imidization can be controlled to a reasonably accurate scheduled end point, and the degree of imidization to the polyimide can be measured without removing the polyimide from the microwave device or using destructive testing methods. be able to.

By using the method of the present invention, the processing time was reduced to 1/30. The present invention is directed to a process for coating an integrated circuit such as a microcircuit with a polyimide film or other substrate such as a semiconductor substrate containing metal and / or electrical wiring in an insulating substrate, an electrically insulating substrate and combinations thereof. Can be used in the coating process.

To implement one embodiment of the present invention, it is essential to use a microwave device that includes an adjustable microwave resonant cavity that can be tuned to resonate the system during processing.

In one embodiment, the present invention provides a method for automatically introducing a polyimide precursor containing a polyamic acid group, a polyamide ester group, or the like, into a microwave device that applies microwave radiation to the precursor. And systems and apparatus for making polyimide. The precursor is a workpiece in combination with a microwave device including an actuator. The workpiece is then exposed to microwave radiation. If the workpiece is a polyamic acid, the workpiece is irradiated to convert to polyimide. Also, by first removing the solvent from the precursor using radiation, imperfections in the precursor such as voids and surface irregularities (eg, depressions) can be avoided. One feature of this microwave device is that it includes tunable microwave resonant cavity means. Another feature of this device is to control the extent and rate of imidization of the precursor by adjusting the power of the microwave radiation during imidization by using inputs whose output can be varied. is there.

It has been found in accordance with the present invention that when the physical properties of the workpiece change as a result of the irradiation, the Q-factor of the actuator also changes and can be monitored during imidization. If the workpiece is a polyamic acid, depending on the extent of the change to be achieved (imidization) from the precursor in the freshly charged solvent to almost complete cure, some combinations of Q factor and temperature may be used. The processing cycle can be stopped in any one of them.

A Q factor in the expression used throughout this specification is a quality factor of a microwave cavity (herein referred to as a working cavity) having a workpiece therein, which has changed the height of the cavity. Sometimes by monitoring the microwave power reflected from the power coupling into the cavity, it is determined from the reciprocal of the width at half the height of the resonant dip obtained as shown in FIG. This is shown in FIG. 4, where the reflected power is shown relative to the height of the cavity.

In FIG. 4, the height of the cavity when a single precursor containing a polyamic acid (or ester) is exposed to microwave radiation in such a device is shown on the X-axis and the reflected power is shown on the Y-axis. In the initial phase of this process, the width of the resonance curve (FIG. 4) is relatively large, and therefore the Q factor is low, because the precursors absorb energy relatively strongly. As the imidization proceeds and the solvent is removed, the microwave power absorbed by the sample decreases, so the width of the resonance dip in FIG. 4 is reduced, which means that Q has increased. Since the absorption of microwave energy is temperature dependent, it is governed by the (loss factor) and also by the physical state of the film (eg, glass or rubber), so the Q factor is also temperature dependent. Will be.

At each of the time intervals T1, T2 and T3 in FIG. 4, the microwave resonance of the tunable cavity of the device changes as the structure of the polyamic acid changes. That is, the polyamic acid / solvent combination is converted to a predominant polyamic acid and polyimide product and combination having residual solvent in the material. This combination of the polyamic acid and the polyimide product and the solvent remaining in the material is substantially freed from the solvent with almost no solvent removal between the two extremes and varying degrees of imidization and is almost completely polymerized to the polyimide. This causes a change in the resonant state of the cavity, which is compensated by tuning so that the cavity has maximum resonance (critical coupling), and the maximum resonance is a state in which the reflected power is minimum (or the reflected power is low). Zero state). Adjustment of the cavity is carried out by moving the microwave device shot 10 up or down and moving the coupling probe 22 into or out of the cavity during the course of the process.

As an example, the power levels P1 to P1 of the polyamic acid precursor dissolved in a solvent coating on a plate arranged on the bottom wall 8 in the adjustable microwave resonant cavity device 2 of FIG. P4 applies. Power is applied during four time intervals of 8,000, 9,500, 10,000 and
The Q value of 10,500 is developed to drive off the solvent from the film first, then proceed from partial to almost complete imidization. The following table summarizes these steps.

[Table 1] Output Q Temperature P1 8,000 130-150 Start of solvent removal P2 9,500 170 Further solvent removal P3 10,000 180 Imidation started, removal of residual solvent P4 10,500 250-350 Imidation completed

The Q factor is combined with the sample temperature to provide a "hardening quality" factor "Z". This "Z" factor is a value that represents the state of cure of the system (as determined by IR and the like).
The analytical relationship between Z, Q and temperature can be ascertained from a series of measurements of the degree of conversion of precursor to polyimide, temperature and Q, which can be ascertained by FTIR and its equivalents. Thus, a Z factor is obtained by measuring the value of Q at a defined temperature and a defined degree of conversion, and any work piece or microwave device whose physical properties change upon exposure to radiation. It is an absolute value that can be measured for a reactant when used.

The degree of imidization to polyimide in subsequent runs to obtain partial or almost complete imidization using the Z factor can then be clearly indicated, Thus, it is possible to provide a method for measuring the degree of imidization without removing the material from the microwave device. This is a non-destructive test method for confirming the degree of imidation at the natural position as it is, but is not limited to the use in the imidization reaction.

Thus, the present invention can be applied to any process that absorbs microwave energy. The output of the microwave device is changed based on Z with the passage of time, and an almost accurate end point of the reaction is grasped in the shortest time to obtain a product of desired quality, for example, a substantially uniform physical property without voids and Obtain one having electrical characteristics. For the production of a polymer film which foams for the capture of the reaction product (alcohol and / or water if the polyamic acid or ester precursor is converted to a polyimide) or for the use of the precursor in combination with a solvent. In contrast, when applying the microwave energy according to the present invention, the microwave output can be varied based on Z over time to produce a film substantially free of defects in a minimum amount of time.

Although the method of the present invention has been described in connection with the production of a polyimide film, the present invention can be applied to the production of any compound, and the sample or reaction can be carried out in either the production of an organic compound or the production of an inorganic compound. The environment absorbs microwave energy. For example, the process of the present invention may be used to make laminates based on polyesters, epoxies, phenols, acrylics and the like, or to make non-laminate structures of such polymeric materials. Similarly, the ceramic material may be dried and / or reacted using the method of the present invention.

The removal of the solvent from the photoresist to a precise level, especially when removing the solvent in the precursor prior to curing by automatically applying the microwave power, especially when removing the solvent is the growth of crystalline material. The process of the present invention can also be used to remove solvents or liquid reaction media from by-products of physical processes or chemical reactions and to dry other materials in various similar applications, such as to promote solvent removal from substrates using the process of the present invention. Can be removed.

The present invention is described in the context of an adjustable microwave cavity that can maintain resonance of the system by changing the height or radiation frequency of the cavity or the position of the probe 22 within the cavity. However, other systems that do not use a microwave resonant cavity can be used to utilize the process of the present invention. By changing the frequency of the microwave radiation, the best properties of this type of device can be obtained, and in this latter respect a swept oscillation system has been used. For example, a sample that does not enter the cavity is exposed to microwave radiation by one or more microwave antennas, similar to a radar antenna.

The physical parameters that control the physical processes that require the application of microwave energy or the removal of solvents or liquids from the sample to obtain the best results, such as the imidization of the polyamic acid precursor, are radiation frequencies. (Ie, radiation that must be absorbed by the sample) and field strength. The power of the radiation is related to the square of the electric field strength. A sample, such as a polyimide precursor, is deposited on the surface to form a surface layer of thickness "d". When radiation is applied, a sample, such as a precursor molecule, absorbs the radiation and generates heat at the location on the molecule where the radiation was absorbed. This heat flows out of the point where it is generated and heats the sample. Because thin films have a large surface area (relative to their volume) and much of this heat is lost at the surface, the sample removes liquids or solvents and continues processes such as precursor imidization. Can't reach enough temperature. Thus, the electric field must reach a minimum Emin before the solvent or liquid can be removed and the next process such as imidization can take place. If the electric field exceeds the maximum value Emax at the same thickness "d", the sample temperature rises too quickly, causing the solvent or liquid in the sample to boil and generate bubbles, resulting in the imidization of the polyamic acid precursor. As the viscosity increases, bubbles are trapped and the solvent is expelled. As a result, bubbles are generated in the sample. Therefore, if the thickness of the sample is "d" and Emax
And Emin have a function dependence on "d", the thicker the sample, the longer the evolved volatiles, i.e., the distance traveled or diffused to the sample surface where the trapped gas is released. Therefore, as "d" increases, Emax decreases. As the thickness of the sample increases, the volume of this material also increases, so the Emin curve shows an increase as the thickness of the sample increases. The applied power is proportional to E. If the thickness increases at a given E, the temperature will not increase much as power is absorbed by more material. Thus, as the thickness increases, Emin must increase due to solvent bleed and subsequent imidization periods. This is shown in the graph of FIG. Placing the system under a vacuum reduces the absolute value of Emin, and increasing the pressure increases the absolute value of Emin.
This principle is still valid.

The process that proceeds after the solvent evaporates has a maximum E and a minimum E that initiates imidation. If the maximum E is exceeded, the rate of solvent vapor generation during the imidization period is outside the sample. Solvent vapors are trapped in the sample above the rate of diffusion of the solvent into the sample, causing air bubbles and cracks in the sample.

In directing imidization in accordance with the present invention using the apparatus disclosed herein, if the vapors formed during the imidization process are not removed from the system, the surface of the polyamic acid and / or polyimide being formed To form surface irregularities which eventually adversely affect the physical properties of the polyimide. Further, the condensation of the solvent on the film during processing adversely affects the quality of the film, the frequency of occurrence of voids, and the flatness.

Steam from this viewpoint includes water vapor and / or a solvent used for dissolving the polyimide precursor. Water vapor is mainly caused by a dehydration mechanism that promotes imidization of polyamic acid to polyimide. It exists.

Accordingly, the microwave resonant cavity is provided with vapor removal means, which uses a perforated short 10 or uses a screen in place of the perforated short 10 to remove the vapor from the chamber. be able to. Ports communicating with the interior of the chamber are strategically located around the edge of the chamber. These ports are connected to vacuum means, pressurized gas or both. For example, an inert atmosphere can be provided around the sample by using an inert gas such as nitrogen.

It has been discovered that film quality can be improved by introducing a process to remove the solvent prior to active conversion of the precursor to polyimide. This can be achieved by adjusting the initial power of the microwave device in this process, allowing the temperature of the precursors to rise sufficiently to control the solvent as a vapor before imidization is complete. To allow the precursor and the formed polymer to be substantially free of voids and solvents. Also, because the power of the device is adjusted to sufficiently prevent foaming of the film while driving the vapor, the precursor and the polymer formed are foam-free products. That is, the resulting product is substantially free of voids and solvents. In general, the precursor can be dried in 2 minutes, using a convection dryer to remove the solvent at 130 ° C. for 1 minute to remove the solvent.
This is in contrast to the conventional technique of time processing.

The process of the present invention is ideally suited for applying a polyimide coating to a substrate, and is particularly suited for coating or applying a film layer to a microcircuit or manufacturing a sandwich-like microcircuit structure. Thus, polyimides can be applied to semiconductor materials or electrical insulators with electrical conductors and combinations thereof using the process and apparatus of the present invention, such as alumina ceramics, glass ceramics, silica magnesium alumina. It is well suited for silica magnesium alumina with internal metal wiring, alumina with metal wiring and pads, metal lines and pads covering Kapton® polyimide.

It has also been found that the process and apparatus of the present invention disclosed and described herein can be effectively used to produce acetylene terminated polyimides in a fraction of the commonly used processing time. . Acetylene or thermistor (Thermid®) 615, 601, PMR-15
The key to treating precursors for other functionally terminated polyimides or polymers, such as US Pat. No. 3,845,018, 3,864,309 and 3,879,349 is isoimide And the ability to achieve different degrees of reactivity between acetylene end groups or between amic acid and acetylene end groups. Usually this is achieved by very slowly heating the precursor. Fast heating results in a simultaneous reaction of both groups, resulting in a high stress polymer film with poor mechanical properties.

By using the method and apparatus of the present invention, imidization proceeds in a controlled manner. That is, the amide acid or isoimide group on the amide acid present in the THERMIT (registered trademark) 615 film is almost completely converted to the imide form in 3 to 5 minutes without reaction of the acetylene group, and the solvent removal is almost completed. . Prior art methods of slowly heating these polyamic acid materials occupied by acetylene not only resulted in the formation of polyimides, but also resulted in the polymerization of the molecules being effected via acetylene groups. A new composition of the material is thus obtained, in which the polyamic acid groups in this class of material are hardly polymerized and are almost converted into polyimides having acetylene end groups available for subsequent polymerization. Subsequent polymerization is obtained by post-firing these materials using conventional dryers or microwave systems, particularly those having adjustable microwave cavities, or other suitable heating means. Even if the imidization reaction is not completed in the first microwave treatment step, it is completed by calcination, and the acetylene end group reacts. Furthermore, even if not all of the solvent is removed in the first stage of the process, it can be removed during post-cure. The total processing time is 20 minutes (including about 3 to 5 minutes for exposing the precursor from the process of the present invention to microwave radiation) compared to 8 hours using the prior art method. .

The mechanical properties of these acetylene-terminated polyimides subsequently cured according to the process of the present invention can be observed by DMTA chromatograms and stress-strain analysis. The properties of these materials are compared to those of samples cured by conventional heating means. The glass transition temperatures are the same (within experimental error), the initial tensile strength is the same, and the tensile strength above the glass transition temperature is the same. Furthermore, Tg is 400
It increases with prolonged exposure at [° C] and increases at 4 [° C] /
It is observed that the time is exactly the same for both the microwave treated material and the conventional treated material. This shows that the accelerated cure cycle of this invention for this class of acetylene-terminated polyimides does not harm the mechanical properties of this material and is different from using extremely rapid thermal curing at elevated temperatures. I have. Furthermore, the elongation at failure is the same, showing the same toughness between the microwave sample of the present invention and the prior art loose heat sample.

FIG. 1 shows an adjustable microwave resonant cavity device 2 according to the present invention. The resonant cavity device 2 has a cylindrical side wall 4, a top wall 6 and a bottom wall 8, on the inner surface of the bottom wall 8 of which a sample of a polyamic acid precursor can be arranged. The side wall 4 of the resonance cavity device 2 is provided with an opening through the opening 9 and the nipple 29, but may be provided so as to penetrate not the side wall 4 but another structure, for example, the bottom wall 8. A plate-shaped short 10 is provided so as to be able to slide inside the side wall 4, and a sliding seal 11 is provided on a peripheral edge of the plate-shaped short 10. The side wall 4 is made of stainless steel and its interior is highly polished so that microwave radiation can be effectively reflected. Also, the inside of the side wall 4 may be coated with a material that reflects microwave radiation to a high degree but does not readily oxidize, such as gold, silver-gold alloy or the like. Since the plate-shaped short 10 has holes 12 provided over the entire surface, the plate-shaped short 10
The vapor in the chamber formed by the upper and lower surfaces, the side wall 4, the top wall 6 and the bottom wall 8 can pass through the plate-shaped shot 10. Instead of the plate-shaped short 10, a screen functioning as a "short" may be used. Side wall 4, plate-shaped short 10 and bottom wall 8
Conduit 20 is formed using nipples 29 that penetrate the side walls 4 and openings in the chamber formed therebetween.
The control rod 14 is rigidly attached to the shot 10 and is controlled by a plate 16 having an opening 18 therein.
They are held so as to have a certain distance from each other. The hole provided in the upper wall 6 receives the control rod 14 so as to be slidable, so that the control rod 14 can slide through the upper wall 6. Since the microwave probe 22 is slidably mounted at the base of the side wall 4, it can move in or out of the chamber formed between the lower surface of the shot 10, the bottom wall 8 and the side wall 4. The microwave probe 22 can be moved using a rack 24 and pinion 26 or screw assembly operatively coupled to the prime mover 28. The prime mover 28 may be operated by a computer controlled or manually controlled electric motor or manually. At the outer end of microwave probe 22 (ie, the end that does not protrude into device 2), microwave probe 22 is operatively connected to a microwave source. The microwave source can be better understood by referring to FIG. 2, which shows a microwave processing system 30.

The microwave output is from 5 [watts] to 1,000
[Water] can be anywhere, especially from 50 [Water]
600 [wat] may be sufficient. Generally, in one embodiment of the present invention, a 500 [watt] power supply is used. The microwave frequency of microwave equipment is 300 [MHz] to 1
Any of the frequencies up to 20 [GHz] may be used, and particularly useful frequencies are 915 [MHz], 2,4
50 [MHz] and 28 [GHz].

The microwave processing system 30 of FIG. 2 is such as a Micro-Now.RTM. Model 420B1 operatively coupled to a three-port circulator 34 such as Ferrite Control No. 2620. It has a microwave source 32. The three-port circulator 34 is operatively connected by a connector 36 to a dummy load 38, such as a NARDA 368BN. Also, the three-port circulator 34 is operatively coupled to a directional coupler 42, such as a NARDA 3043B, which includes a power meter and a sensor, such as an HP435 device from Hewlett Packard. Functionally coupled to 44 and 46. The directional coupler 42 is then operatively coupled to the microwave probe 22 by a coaxial cable or a suitable waveguide 48. The short 10 shown in FIG. 1 is moved upward or downward in the resonance cavity device 2 by a prime mover (for example, an electric motor) 50. Prime mover 50 is operatively coupled to worm drive 52 in a manner well known in the art. A controller 54, including a computer, controls the microwave source 32 via conduit 56, power meters and sensors 44 and 46 via conduits 58 and 60, the prime mover 28 via conduit 61, and the prime mover 50 via conduit 62. I by conduits 64 and 70
It is functionally coupled to the R pyrometer 66 and the optical pyrometer 68, respectively.

In use, the polyamic acid precursor is dissolved in a solvent and coated on a base such as a microcircuit, and the microcircuit thus coated is connected to the bottom wall 8, side wall 4 and short-circuit of the resonant cavity device 2. It is located in a cavity between ten. The microwave source 32 is turned on, and the microwave is radiated from the probe 22 into the chamber of the resonance cavity device 2. Since the dielectric constant of the system changes,
Probe 22 moves into or out of the chamber to match the impedance of the system. The power is provided by a programmed controller 54 responsive to the temperature of the sample in the resonant cavity device 2 measured by the optical pyrometer 68 and the temperature of the chamber monitored by the IR pyrometer 66 or equivalent. Controlled. The power reflected from the resonant cavity device 2 is measured by a power meter and sensors 44 and 46, which then relay this information to a controller 54. Controller 5
4 transmits the programmed response to the prime mover 50 so that the shot 10 is moved up or down, and the probe 22 is moved inside or outside the microwave resonance chamber in the resonance cavity device 2, whereby the reflected power To achieve the critical coupling of this system as in the system defined herein. In one example, controller 54 is programmed to provide power to the device to obtain a temperature distribution over time, as shown in FIG. Also, the application of power to obtain the temperature and the movement of the shot 10 to obtain the critical coupling as shown in FIG. 3 are effective not only by using the controller 54 but also manually.

One feature of the resonant cavity device 2 is that it includes means for removing vapors (eg, solvent and / or water) from the chamber of the device so that they do not condense and redeposit on the sample being processed. It is. As shown in FIG. 1, a hole 12 is provided in which the vapor generated during processing of the sample in the chamber below the shot 10, which chamber is defined here, passes through the upper chamber. Allow to pass. The vapor condenses into the upper chamber or is discharged via opening 9 or conduit 20. Conduit 20 is operatively associated with a vacuum pump to further evacuate steam and further empty the chamber below shot 10 more completely. External fluid such as dry, dust-free clean air or similar gas enters the lower part of the device 2 through the opening 9 or nipple 29 opened in the lower part of the side wall 4 and
Discharged via conduit 20. In addition, short 10
Include a non-perforated plate (a plate having no openings therein) and strategically place a series of conduits along the length of the side wall 4 along the inner surface of the side wall 4. A series of conduits operate simultaneously or in parallel to empty the chamber above or below the chamber 10 when the volume of the chamber is being changed by movement of the chamber 10 upward or downward, and the resonant cavity arrangement. 2 can be empty.

Since the opening 18 provided in the plate 16 and the short 10 are aligned, the pyrometer 68 can aim at the sample through the opening of the upper wall 6 and the short 10 and focus on the sample. Alternatively, a fiber optic temperature probe may be used in place of the pyrometer, and the focus may be focused on the sample through the opening provided in the side wall 4.

The present invention uses a computer to monitor the reflected power of the microwave and adjust the sliding shot 10 and input probe 22 to operate to minimize the reflected power, thereby reducing the cavity. Also, the present invention relates to a system for maintaining resonance.

Initially, the system of the present invention, programmed in controller 54, causes sliding shot 10 to return to the "home" position below the desired resonance point. The shot 10 is then raised one step at a time, and the reflected power after each of those steps is read from instruments 44 and 46. If the reflected power decreases below the threshold indicating an approach to a resonant dip as shown in FIG. 4, the step size is reduced and the sign of the difference between the last two data points and the power of the two data points is reduced. The direction of the step is controlled depending on the absolute position of the shot when the value is measured. As the reflected power continues to decrease below other thresholds, the step size becomes even smaller. When the reflected power reaches a minimum, the computer program in controller 54 uses the same difference between the reflected power and the absolute position to determine which direction to move further to further reduce the reflected power, and input The probe 22 is moved to generate a signal that matches the impedance of the cavity.

This routine can reduce the microwave output reflected from the cavity to less than 0.1% of the forward power. More importantly, this routine "tracks" the cured polymer system so that the system remains in resonance throughout the processing cycle.

A second system, programmed in controller 54, requests the shot 10 to travel a large distance and cross the resonance dip, and also records the level of reflected power to locate the minimum at the location where the minimum is found. Return 10. If the reflected power is not zero, a similar routine output from processor 54 will
Work on 2 to find the minimum for that axis and the program execution is briefly returned to find the location of the minimum reflected power. This repetition continues until the reflected power becomes zero. This second routine or the first routine described above can then be called to maintain resonance for the remainder of the processing cycle. Generally, these routines only take about 15 seconds to find a resonance.

FIG. 6 is a flowchart for designing the entire control system according to the present invention. The control system of the present invention can be run on any computer, such as an IBM 370 computer, an IBM personal computer such as a PC / AT or more complex models, and other stand-alone computers with similar capabilities. The programming languages used to program the control system according to the present invention include basic, autorun, assembly language, C language and similar languages.
Any suitable language is acceptable.

Block 100 in FIG. 6 is a system call,
That is, it indicates a command to execute the control system. Line 102 indicates the signal that passes control to block 104. Block 104 illustrates the initialization of the A / D converter for power meters 44 and 46. The A / D converter is a 16-channel A / D converter (model DAS-16 manufactured by Metrabyte). This A / D converter requires at least three inputs. That is, 1
One for temperature, one for incident power, and one for reflected radiation power. The directional coupler 42 separates 1% of the input power and 1% of the reflected power to the respective output meters and sensors 44 and 46 (these instruments are microwave output sensors from Hewlett-Packard Company). Instrument, model HP-435B). When the A / D converter is initialized for the first time, the multiplexer is set to read the incoming and reflected powers at the predetermined receive rate specified in the program, about 20 to 30 times per second. Is preferred. The temperature monitored by the pyrometer 68 is sent to the A / D converter or the RS-2
Transmit to controller via 32C interface or similar. A /
The input to the D converter is line 58 in FIG. 2, and the input from the power meter and sensor 46 to the A / D converter is line 6
0, input from pyrometer 68 to A / D converter is line 70. The outputs from the power meters and sensors 44 and 46 and the pyrometer 68 generate inputs to the A / D converter, which provides signals indicating input power, reflected power and temperature in the computer on which the control system is running. Occurs. Block 104 corresponds to the initialization of a computer timer corresponding to the running time of the program. 1/18 of one second corresponds to one count in the timer. Thus, the counter, which is initialized to zero at the beginning of a program call, increases by "1" every 1/18 second. Block 104 corresponds to preparing for the next interrupt to be used during the running of the control system. Set a system timer interrupt indicating a subroutine to count events. Upon receiving a count sufficient to allow an event (eg, plotting data on the screen), a flag is set in the interrupt routine, which is later read and executed by the program during normal operation. After execution of the interrupt routine, execution of the program is resumed at the point where the interrupt occurred.

The controller 54 of FIG. 2 is a stepper motor (model numbers 57-51 manufactured by Compumotor) used for the prime mover 28 and the prime mover 50.
Interacts with the prime mover 28 of the microwave probe 22 and the prime mover 50 of the short 10 by a standard serial interface digital communication port RS232C for output to the MPU.

Line 106 indicates the passage of system control signals to block 108. Box 108 shows the presentation of an option screen on a display means such as a CTR display of an IBM personal computer. The creation of an option screen in the C language is described in, for example, Borland Turbo C Reference Guide, Borland Turbo C Reference Guide.
International). Some reasonable number of options are provided at this level, seven of which are activated and selected by the operator of the control system. Option 1 controls the output to the display terminal which plots temperature versus time, forward power versus time, and reflected power versus time. The vertical and horizontal scales are set in option 1. Option 2 controls the Q vs. time plot of the cavity. The horizontal and vertical axes of the Q vs. time plot are controlled in option 2. In Option 3, a sensor can be set that provides temperature versus time data for the Option 1 plot. In the preferred embodiment presented herein, only one temperature monitor for the workpiece is utilized in the control routine described below. Option 4 specifies that only temperature, forward power, and reflected power data over time will be obtained without invoking a temperature control or diagnostic routine. These two routines will be described later with reference to FIGS. In option 5, only the automatic adjustment routine that minimizes the reflected power can be selected without running a temperature control routine or a tuning diagnostic routine defined later, while obtaining the data described in option 4. In Option 6, the operator can select to execute the temperature control routine and the automatic adjustment routine without selecting the diagnostic routine. Option 7 allows the operator to select a diagnostic routine, a temperature control routine and an automatic adjustment routine defined as a complete control system.

The temperature control subsystem, described in more detail below, references a data set containing data on the applied temperature versus time schedule. As an example, FIG. 11 schematically illustrates a plot of a temperature versus time schedule. The data for this is arranged in a data set having three groups of numbers. The first number is the initial temperature for the first time interval, the second number is the linear time rate of temperature change, and the third number is the time duration of constant temperature maintenance or soaking. FIG.
The data read from the file corresponding to the time schedule of T ₁ , m ₁ and t ₂ -t ₁ and T ₂ , m ₃ and O
And T ₃ , m ₄ and O. Required time t ₂ -t ₁ is by connexion determined the current values of the above-mentioned counter. Time rate m ₂ of the temperature change in the time period between time t ₁ and time t ₂ is zero, meaning this is that the workpiece is held between the temperature T ₂ of the time t ₂ -t _1, Usually this is the temperature T
Called retention at ₂ or soaking. The change in temperature over time can be positive or negative or zero. As shown in block 104, the program sets up a flag that increments the counter every 1/18 second, so that the program can hold its own time. The screen for storing and plotting the data measured for the temperature, the forward power and the reflected power is updated once every second. Therefore, one per second on the screen
An additional data point is added, and the plot is eventually completely filled. The Q is checked once every 5 to 30 seconds (the frequency of checking the Q, ie, how often to check once is determined in option 2 of box 108).
The time is confirmed by the value of N in the counter. Here, the true time is N ÷ 18. When N is 18, this corresponds to one second. The time interval for finding the value of Q is block 108
Is set by typing on the screen the number provided as a result of If no value is entered for this time interval, a default value is loaded.

Line 110 indicates the signal for a program control transfer from block 108 to block 112. Block 112 provides a screen for plotting as described above. In the upper left corner of the screen is a list of options, including start execution, data storage, microwave power change, start / stop automatic adjustment routine execution, and (manual) stepper motor (28 and 50 in FIG. 2). Includes changing the stepper motor increment of operation. In the upper right corner of the screen is provided the current value of the data being plotted on the screen, namely the current temperature, forward power, reflected power and heating rate. There is a hold on this screen that is released by pressing a keystroke and is waiting for the start of program control execution.

The plot format shown in FIG. 3 is a format for plotting on the display screen when all the data is acquired. FIG.
Are recreated over time and the data is updated once per second. At block 112, other options besides the start of execution can be selected. It is convenient to use the F key on the keyboard of the IBM personal computer to control these. Other options other than starting program execution include storing data in a data set or data storage location, block 10
At 8 is to turn off or turn on the automatic adjustment routine regardless of which option is already selected and to select directly from the keyboard the radiant power to be applied. Other options are within the skill of the art and may be added at this point in the control routine. The control method of the F key and the display plot in the terminal device is described in some language manual, for example, Turbo C Reference Guide Version 2.0 (Borb International, Borland International).
o Can be found in the C Reference Guide Version 2.0). At block 112, the prime mover 50 that controls the short 10 is actuated to move the short 10 as close as possible to the workpiece. Prime mover 28
To find the zero position of the microwave probe 22 by pulling the microwave probe 22 out of the cavity as much as possible, and then move the motor 28 to the position of the microwave probe 22 where the reflected power is minimized. It is advanced towards the workpiece to an average position which has previously been experimentally determined to be suitable as a starting position. Since this position is automatically optimized by the control program, it is not necessary to know the actual position of the microwave probe 22 exactly. An approximation of the starting position can be obtained by operator intervention or by using the position when the cavity is empty.

Line 114 blocks system control.
16 (FIG. 7). Block 116 indicates that the system receives data from an A / D converter that receives input signals from power meters and sensors 46 and 44 and pyrometer 68 as monitors for forward and reflected power. The data is continuously provided in the system controller as a signal indicating the applied power level, the reflected power level and the sample temperature as part of block 116. Line 118 blocks program control 120
The signal to pass to is shown.

At block 120, a test is made to see if the automatic adjustment flag is set to invoke the automatic adjustment routine. The automatic adjustment routine flag is set at block 108 as described above. If the auto adjust subsystem flag is not set, block 1 is asserted by the signal shown on line 122.
24 to pass system control. A test is performed at block 124 to determine if the screen flag has been set by the interrupt subroutine and if the flag for updating the stored data variable has been set. If the flag for the stored variable update or screen update is not set, the signal indicated by line 126 causes program control to return from block 124 to block 116.

Returning to block 120, if the automatic adjustment flag has been set (generally, being set is being set to "1"), the signal indicated by line 128 indicates that the automatic adjustment flag has been set. Program control is then sent from block 120 to block 130.
Block 130 is a call to the automatic adjustment routine shown in FIG. The transfer of program control to this automatic adjustment routine is made by the signal indicated by line 131.

Line 131 in FIG. 8 shows a call to the auto-tuning subsystem, which leads to block 132. Where α is set to the value of the ratio of the reflected power to the forward power. The first group of shots 10 and microwave probes 22 to be moved to tune the cavities at block 132 are provided as default values for the shots 10. A test is performed at block 134 to determine if the radiated power is on. When the radiant power is not on, program control is sent to block 139 by the signal indicated by line 136. Block 139 is the return signal to block 130 (FIG. 7) as indicated by line 176;
At this time, block 130 calls the automatic adjustment routine.
When the test at block 134 indicates that the microwave output is on, program control is sent to block 140 via line 138. Block 1
A test is performed at 40 to determine if the resonant cavity device 20 has been adjusted. If α is less than a predetermined value, the resonant cavity device 20 is defined as tuned, and the predetermined value is preferably 0.1%. If, as a result of this test, resonant cavity device 20 is found to be tuned, program control is sent to block 139 by the signal indicated by line 142. Block 139 returns control to block 130 of FIG. 7 which called the automatic adjustment routine. If the resonant cavity device 20 is out of tune, the signal indicated by line 144 sends a system control signal to block 146.

At block 146, the prime mover 28 of FIG.
And the step size for the prime mover 50 is set according to the following equation: These prime movers 28 and 50 are Model 57-51 Compumotors, with 12,800 steps per 360 ° revolution. The total number of steps advanced based on the test of α is called an increment. This test is as follows. When 0.1 ≤ α ≤ 0.25, the increment is
50 steps, when 0.25 ≦ α ≦ 0.4, the increment is 80 steps,
When 0.4 ≤ α ≤ 0.65, the increment is 130 steps, 0.65 ≤ α ≤
When 0.8, the increment is 180 steps, and when 0.8≤α≤1, the increment is 250 steps. Also, this increment can be set equal to the ratio of reflected power to forward power (α) multiplied by a constant plus offset. Here, these constants and offsets are inputs that can be entered on the options screen shown by block 108 in FIG.

System control is passed from block 146 to block 150 by the signal indicated by line 148. A test is performed at block 150 to determine if the reflected power has decreased. When the reflected power is not decreasing, that is, when the current value of the reflected power is greater than the previous value of the reflected power, program control is sent to block 154 by the signal indicated by line 152. Block 154 sends a signal to the currently controlled prime mover 28 or 50 to reverse direction. System control is sent to block 162 by the signals indicated by lines 156 and 160. A test is performed at block 162 to determine if the current value of the reflected power is minimal. When the current value of α is less than the value of MINIMUM, MINIMUM is updated to the current value of α and the variable COUNT is set equal to zero. When the current value of α is not smaller than MINIMUM, MINIMUM is not updated, and the variable COUNT becomes CO
Set equal to UNT +1 (COUNT = 0 in block 104 (FIG. 6), minimum is block 104
Is set to a large value). When COUNT is not greater than a predetermined value (preferably "15"), it is confirmed that no local minimum exists and program control returns to line 16
The signal indicated by block 4 is sent from block 162 to block 158. If COUNT is greater than "15" at block 162, then a local minimum is confirmed and system control is passed to block 168 by the signal indicated by line 166. Block 168 changes the control of the prime mover from prime mover 50 to prime mover 28 or from prime mover 28 to prime mover 50, and thereby resonant cavity device 20.
Change the axis to adjust to automatically tune. Program control is passed from block 168 to block 158 by the signal indicated by line 170. At block 158, the increment determined at block 146 is performed on the axis determined at blocks 162 and 168, in the direction determined at block 150 and block 154. Thereafter, program execution is sent to block 139. Block 139 indicates a return to block 130 of FIG. Also, the signal represented by line 172 does not return directly to block 130, but
Returning to block 140, as indicated by 74, the signal (line) which passes program control to block 139 which causes the resonant cavity device 20 to satisfy the .alpha. Condition of block 140 and return to block 130 of the main program of FIG. (Indicated by 142), it is not possible to return to the main routine of FIG.

The signal output from block 130 to the automatic adjustment routine is indicated by line 131, and the input signal to block 130 from the automatic adjustment routine is indicated by line 176.

In FIG. 7, system control is passed from block 130 to block 180 by a signal indicated by line 178 after a call to the automatic adjustment routine. At block 180, a test is made to see if the temperature control flag was set at block 108. When the temperature control flag is set, program control returns to line 18
2 is sent to block 184 by the signal indicated by.
A test is made at block 184 as to whether the timer flag is set. The timer flag is set in the interrupt subroutine. At this point the test is performed,
A determination is made as to whether a temperature control routine should be invoked. The data collection indicated by block 116 is 1
Performed 20 to 30 times per second. The temperature control routine is not executed periodically. The data collection and self-adjustment routine is contained within dashed line 186. The sequence of controls and signals within this outline 186 is between 20 and 20 per second.
Executed 30 times. If the temperature control routine calls this frequently, the system will attempt to control the temperature excessively. The temperature control routine is preferably called once or twice per second. Thus, the data collection segment of the system, indicated by outline 186, is frequently invoked. As described above, the time counter is updated every 1/18 second and the temperature control routine is called twice per second. The temperature control routine is called when the time counter is divisible by nine. When the timer counter is divisible by nine, program control is passed by a signal indicated by line 185 to block 188, which calls the temperature control routine. When the timer counter is not divisible by nine, system control is sent to block 192 by the signal indicated by line 190. Line 194 exiting block 188 directs system control from block 188 to block 19 of FIG.
8 shows a signal to be sent.

A test is performed at block 198 to determine if the temperature is in the holding state (called holding temperature or soaking temperature) specified by the temperature schedule input as described above. When the temperature is in the soaking state according to the temperature schedule, program control is sent to block 202 by the signal indicated by line 200. At block 202, the current time is compared to the time at which the soaking has begun to determine the time that has already elapsed in the soaking mode. System control is passed from block 202 to block 206 by a signal indicated by line 204. Comparing the time specified by the input temperature schedule with the current soak time in block 206, the desired soak determined from the temperature-time input schedule where the current soak time is placed in the soak state. To see if the time has already been exceeded.

The soak flag is initialized at block 104 in FIG. 6 to a value of zero indicating no soak state.
When the soaking flag is “1”, this indicates that the device is in a soaking state.

When the current time at block 206 is greater than the desired time to be soaked, program control is passed to block 210 by a signal indicated by line 208. At block 210, the soak flag is reset to zero, indicating a non-soak state.
Program control is passed from block 210 to block 214 by the signal indicated by line 212. A test is performed at block 214 to determine if the temperature has reached the end of the temperature-time input schedule. This end occurs when there is no longer a segment of the temperature-time input schedule. This can only be performed if the last pass through block 210 resets the soak flag. If the temperature program is not completed,
System control is passed from block 214 to block 218 by a signal indicated by line 216. Block 218 indicates the return of the temperature control routine call to block 188, as indicated by line 196 in FIGS. When the program sends control from block 214 to block 218 via line 216, the temperature control flag is set to "1" or "YES" and program control is cycled through the remainder of the flow indicated by block 186 in FIG. I do. This includes the passage of block 180,
The temperature control flag is still set to "1" or "YES" and system control is passed to block 184 as indicated by line 182.

In FIG. 9, when the temperature control schedule is complete, that is, when there is no more data to be read from the input control schedule, system control is passed from block 214 to block 222 by a signal indicated by line 220. Block 222 resets the end of the program flag initialized to "1" in block 108. When the end of the program flag is set to zero in block 222 of FIG. 9, it is a signal to stop the program, so system control is performed by the signal indicated by line 224.
From 2 go to return block 218 and continue to line 1
Proceeding to the temperature control call block 188 of FIG. 7 by the signal indicated by 96, system control is cycled through the routine contained within the dashed outline 186 of FIG. Block 116 is reached. At block 116, the end of the program flag is zero and the program ends. The program execution may return to block 108, for example, to wait for a new option setting or the like.

In FIG. 9, if the soak flag is zero at block 198, program control returns to line 226.
Is sent to block 228 by the signal indicated by. 1
Performing one test simplifies the program flow, for example, if the next stage is a ramp (rather than a soak), the program is forwarded after passing block 198 (soak = 0). By looking at the initial temperature of the next input "segment" (consisting of one ramp and one soak), contour cooling and circulation can be allowed if necessary.

When the current temperature is higher than the next soaking temperature,
System control is passed to block 232 by a signal indicated by line 230, where the soak flag is set to "1" or "YES". System control is passed from block 232 to block 236 by a signal indicated by line 234. Block 236
The first time at the beginning of the current soak is recorded at, which corresponds to the time recorded in the time counter for each pass of block 236 that occurs only when the soak is initialized. System control is passed from block 236 to block 202 by a signal indicated by line 238. The current time in block 202 is block 2
It is compared to the initial time set at 36, which is compared to the desired soaking time. The time in the temperature profile includes only the soaking time (set to "0" if no soaking). This is the only point at which a time comparison is made to cover the time within the soak. System control is on line 20
The signal indicated by block 4 is sent from block 202 to block 206 where a test is performed to determine if the time within the soak is greater than the desired time. When the time within the soak is greater than the desired time, system control is passed from block 206 to block 210 by the signal indicated by line 208 as described above. When soaking time is set to zero, i.e., when soaking is not required, the program moves to block 210 via line 208 as described above,
Reset the soak flag. When the current in-soak time is not greater than the desired in-soak time, system control is initiated by a signal indicated by line 240 to block
6 to block 242. At block 242, a test is made of the current value of the temperature to the desired time in the current segment time of the temperature time schedule. When the temperature is not different from the desired temperature, system control is passed from block 242 to block 214 as indicated by lines 244 and 212. When the temperature at block 242 is different from the desired temperature, system control returns to block 2 as indicated by line 246.
From 42 is sent to block 248. A test is performed at block 248 to determine if the temperature is higher or lower than the desired time. When the temperature is lower than the desired temperature, an output signal is sent from the controller 54 shown in FIG. When the current temperature is higher than the desired temperature, the output signal is
To reduce the power output of When the current temperature is lower than the desired temperature, the output signal indicates to increase the power output of the microwave source 32. Although a number of temperature control algorithms can be used, the following method is preferred. The power is changed according to the following relationship.

New power = current power × (desired temperature / actual temperature) System control is passed from block 248 to block 214 by signals indicated by lines 250 and 212. The remainder of the temperature control routine passes through block 214 as described above.

When the current temperature is below the next soak temperature in block 228 of FIG. 9, system control is passed from block 228 to block 254 by a signal indicated by line 252. In block 254, a least squares linear fit is performed on successive data points of temperature versus time to determine the heating rate. This data point is preferably five. After determining the heating rate, system control is passed to block 258 by the signal indicated by line 256. At block 258, a check is made as to whether the heating rate is greater or less than the desired rate. When the heating rate is neither greater nor less than the desired rate, system control is sent to block 214 by the signal indicated by line 260. When the heating rate is greater than or less than the desired heating rate, line 262
The system control is controlled by the signal indicated by block 258.
Is sent to block 264. The desired heating rate is the heating rate entered in the time / temperature schedule from the input data set as described above. At block 264, the power output of the microwave source 32 of FIG. 2 is increased or decreased as follows. That is, the new power is equal to the current power times the ratio of the current speed to the desired speed. Another method is to give the power a fixed amount increment, for example 5 watts, which can be set in block 108 in FIG. In block 264, the signal indicating an increase or decrease in the current power output of microwave source 32 is a signal at 0-10 volts input transmitted along line 56 from controller 54 to the input of microwave source 32 from controller 54 of FIG. Controlled by 10 [V] corresponds to full power. This signal voltage is DAS-16 (metrabyte,
Generated by the digital-analog section of the Metrabyte card. The desired power change is made at block 264 and system control is sent to block 214 by the signal indicated by line 266. The remainder of the temperature control routine beyond block 214 has been described above.

System control is passed from the return block 218 of FIG. 9 to the block 188 of FIG. 7 of the temperature control routine by a signal indicated by line 196. System control is controlled by signal indicated by line 268.
88 to block 192. At block 192, a test is performed to determine whether the diagnostic flag has been set. When the diagnostics flag is not set, system control is activated by the signal indicated by line 270.
4 At block 124, it is checked whether the current values of the temperature, time, forward power, and reflected power are stored in the storage locations, and at block 112, it is checked whether the plot on the screen set up is updated. If this is the case, program execution moves to block 272 using line 271 and
The data for the current data point is updated on the screen settings in block 112 as described above. System control is passed from block 272 to block 116 by signals indicated by lines 274 and 126, and
At this point, the program stops when the program control flag is set to zero or off.

When the diagnostic flag is set to "1" at block 192, system control is passed to block 278 by the signal indicated by line 276. A test is performed at block 278 to determine if the timer flag has been set. Since it takes a few seconds to run the diagnostic routine, the diagnostic routine is called at a much lower frequency than the temperature control routine or the automatic adjustment routine. The diagnostic routine is called every 5 to 30 seconds. As described above, the time counter is set to "1
When "8" this corresponds to one second, so when the diagnostic routine is called every five seconds, program control is passed from block 278 to block 282 by the signal indicated by line 280. At this time, the counter is N × 5
It has a value equal to × 18, where N is an integer.

[0085] If this condition is not met, system control is activated by the signal indicated by line 284.
8 is sent to block 124, and the execution of the system from block 124 onward is similar to that described above. When program control is sent to block 282, the diagnostic routine is called and system control is sent to block 288 of FIG. At block 288, the system issues a signal to move the short 10 closer to the workpiece until the system receives an input from the output meter and sensor 46 indicating that the reflected power is 30% of the signal received from the meter 44. Send to prime mover 50. These are the minimum step sizes of the stepper motor. Conventionally, the Q of a cavity is measured from the width of the reflected power at half height. However, it was confirmed that a value similar to Q could be obtained by measuring the width in less than half the height. The Q of the resonant cavity device 2 is determined as twice the distance that the shot 10 must travel to provide 30% detuning. Accordingly, block 288 corresponds to confirming the current value of Q. System control is passed from block 288 to block 292 by a signal indicated by line 290. Currently, the resonant cavity device 2 is adjusted again by calling an adjustment routine. The system cycles through the adjustment routine until the reflected power falls below 1% of the forward power. After the resonant cavity device 2 is returned, system control is returned to block 292. System control is passed from block 292 to the adjustment routine, as indicated by line 294. As shown by line 296, system control is signaled from the adjustment routine to block 292.
Is returned to. System control is passed from block 292 to block 298 as indicated by line 300.

As described above, an empirical Z factor is determined by experimental observation. Z corresponds to the percentage of cure of the sample. For example, if the workpiece is a polyamic acid that is being cured to a polyimide, Z corresponds to the percent cure to the polyimide. The relationship between Z, Q and T is to stop the microwave radiation and process the sample at a point where the sample can be cooled without any change in the physical or chemical processes occurring during processing. Can be best confirmed. During this period, Q and T are monitored (by tuning the microwave for a short time with low power). This process then results in Z
= F (Q, T). This represents empirical data to which the formula for determining the function can be fit, where Z = f (Q, T), and f is determined by a curve that fits this data. From the analysis of empirical data, Q where the change in Z occurs rapidly
-The presence of the T data area is known and the preferred Z vs. T
History can be determined. This is shown schematically in FIG. Curve 308 is the history of Z vs. T, which is the preferred expected history desired to work most effectively on the workpiece. For example, in the case of curing the above-mentioned polyamic acid to polyimide, FIG.
There are two regions where Z changes rapidly, as shown in Figure 2; in this region, when the polyamic acid is dried and the solvent is removed to cure the solvent-free polyamic acid into polyimide, Z is further carefully taken. It is desired to control. In the following description, expected Z means a general curve of a type like 308 shown in FIG.

At block 298, the current value of the Z factor is determined using the current temperature and the current Q. The current Z factor represents a Z factor determined from an equation or data list based on experimental observations. System control is passed from block 298 to block 312 by the signal indicated by line 310. In block 312, the current Z factor is compared to the expected or desired Z factor for the current temperature. When the current Z factor is greater than expected, system control is passed from block 312 to block 316 by the signal indicated by line 314. Since the current Z indicates that the physical state is ahead of the expected Z,
At block 316, an output signal is sent from controller 54 along line 56 to indicate that the power output of microwave source 32 should be changed. If the current segment of the temperature versus time profile has a temperature ramp, the ramp is increased to cause this segment of the temperature versus time profile to exit more quickly. Also, when the segment of the temperature versus time profile is in a soaking state, the soaking is terminated and the segment of the temperature versus time profile exits faster. System control is passed from block 316 to block 320 by a signal indicated by line 318. A temperature control routine call that continues at block 320 to the next segment of the temperature versus time profile. System control is passed from block 320 to block 322 by a signal indicated by line 324. Block 32
2 is the return to block 282 of the main routine of FIG. 7, and line 326 represents the return signal to block 282.

When the current value of Z is less than the expected value of Z at block 312, this indicates that the current physical state is behind the expected state, and system control returns to the signal indicated by line 328. Block 31
2 to block 330. At block 330, a signal is sent from controller 54 to microwave source 32 along line 56 of FIG. 2 to reduce the slope of the input profile to extend the time within the current segment of the temperature versus time profile. Alternatively, the current Z is raised to the expected value of Z by increasing the soak time to extend the time spent in the soak segment of the temperature versus time profile. Program control is on line 332
Are sent from block 330 to block 320 as indicated by. The progress of the system from block 320 has already been described. When the current Z is equal to the expected Z at block 312, system control returns to line 334.
Block 312 to block 3 by the signal
22. Line 326 at block 322
Control is sent to block 282 by the signal indicated by
The diagnostic routine is called at block 282. At this time, system control is passed from block 282 to block 124 by the signal indicated by line 328 in FIG. The progress of the program since block 124 has already been described.

FIG. 13 is a schematic diagram summarizing the main points of the control system shown in FIGS. 6, 7, 8, 9 and 10 in detail.
In block 330, the program is initialized, and in block 330, elements 100, 102, 10 of FIG.
4, 106, 108, 110, 112, 114. Line 332 represents the transfer of control from block 330 to block 334 by a signal. Block 334 represents the data collection and display functions of the control system. Block 334 receives a signal indicative of forward power FP, as indicated by line 336, from the power meter and sensor 46 of FIG. Block 334 provides a signal indicative of the reflected power, as indicated by line 338, in the power meter and sensor 4 of FIG.
Receive from 4. Block 334 receives a signal from pyrometer 68 of FIG. 2 indicating the current temperature of the workpiece, as indicated by line 340. System control is line 3
The signal indicated by 42 is sent from block 334 to the automatic adjustment subsystem of block 344. These three
A test is performed with two input signals to confirm that the ratio of reflected power to forward power is less than a predetermined value (preferably 0.01). When this condition is met, system control is returned to the data collection and display function of block 334 by the signal indicated by line 346. When the test of whether the resonant cavity device 2 is tuned is not satisfied, a signal indicating how to move the shot 10 of FIG. When a minimum in the reflected power is found after moving the prime mover 50, a signal indicating how the prime mover 28 should be moved is provided to control the position of the microwave probe 22 and to control the position of the microwave probe 22 in FIG. Relatedly, the reflected power is minimized (the movement of the microwave probe 22 and the shot 10 may be performed in any order and may be repeated many times). When the tuning condition is satisfied, system control is returned from block 344 to the central control system, indicated by block 334, by the signal indicated by line 346. The central control system reads the temperature versus time schedule. Temperature control is reinstated, and system control is turned on by the signal indicated by line 348.
4 is sent to a block 350 which is a temperature control routine. When the end of the temperature versus time schedule is reached, system control returns to block 35 as indicated by line 352.
From 0 to the central control unit 334, the system ends. If the end of the temperature versus time schedule has not been reached, a test is performed to determine if the current temperature is the temperature dictated by the temperature control schedule. When the temperature differs from the temperature indicated by the temperature control schedule, a signal indicating how power should be controlled to match the temperature to the temperature control schedule is transmitted to microwave source 32 via line 56 in FIG. Sent. When the current temperature is equal to the temperature specified by the temperature versus time schedule, system control is initiated by the signal indicated by line 352 to the temperature control unit 350.
To the central control unit 334. If an end point detection subsystem is required, system control is transferred to line 354
Are sent from the central control unit 334 to the block 356 by the signal indicated by. Block 356 represents the end point detection routine. The reflected power is 30 of the forward power
The current value of Q is measured by sending a signal along line 62 to prime mover 50 indicating that shot 10 should be moved toward the sample until [%]. System control is controlled by a signal indicated by line 358 in block 3.
From 56, the automatic tuning routine 344 is passed, and the resonant cavity device 2 returns to the tuning state. As indicated by line 360, program control returns from the automatic adjustment routine 344 to the end point detection routine 356. The current Z value is determined using the current Q value and the current T value, and this value is compared to the expected Z value. When the current Z value is equal to the expected Z value, system control returns to line 357.
The control is moved from the routine for detecting the end point of the block 356 to the central routine of the block 334 by the signal indicated by.
When the current Z value is not equal to the expected Z value, a signal indicating that the applied power is to be increased or decreased to change the temperature ramp rate or to extend the soaking is indicated by the line in FIG. It is sent to the microwave source 32 via 56. Each forward power, input signals 360, 362 and 364 shows the reflected power and temperature are monitored N _l times per second. The output signal 366 instructing the display update is 1
Output _Nd times per second. The auto-adjustment routine, indicated by block 344, is called _Na times per second. The temperature control routine represented by block 350 is called _Nr times per second. The end point detection routine indicated by block 356 is called N _e times per second. In general, the following inequality can be applied: N _l > N _a > N _r >
_Ne . N _d may be filed at once per second.

In summary, the auto-tuning subsystem basically minimizes the reflected power in the following manner. That is, the ratio of reflected power to forward power is first used to determine whether approaching or moving away to a minimum (local or global) and confirm the state of adjustment. Next, based on the above, the direction in which the motor should be rotated is determined (the default value is initially given). Next, the step size to be adopted is determined. If you get closer to tuning, reduce the step size. Next, determine if it needs to be activated (not required if synchronized). Next, it is determined whether the axis should be changed (since one minimum has been reached). Next, the shot 10 or the microwave probe 22 is moved in a desired direction by a desired distance. Also, the shot 10 or the microwave probe 22 is swept over a fairly large range and then returned to its minimum position, after which the other axes are moved in the same way or in the manner described above. These two approaches can be applied in combination, for example, by moving the prime mover stepwise until the ratio α begins to decrease, and then causing the prime mover to sweep significantly. Since the position where the movement is started is close to the tuning, the size of the sweep can be reduced.

In summary, the temperature control subsystem operates as follows. First, the temperature, preferably the surface temperature, is measured. Next, the heating rate is checked and compared with the input temperature profile. The microwave power is then increased or decreased to obtain a suitable heating rate or a suitable steady state temperature. The amount of change is determined by the system controlling the microwave generator, preferably using an analog signal. When the heating cycle is complete, the system shuts down (eg, by resetting a flag). In summary, the endpoint detection subsystem operates as follows. First, check the temperature. Then check the value of Q or a similar value for the cavity / workpiece. Next, a Z factor or similar factor is calculated. The Z factor or Q and temperature combination is then compared to the desired profile. Next, it is determined whether the current segment should be ended (moved to the next segment) or the program execution should be ended. If the combination of Z or temperature and Q is not as expected, determine whether to extend the segment.

As described above, the present invention has been shown and described based on the preferred embodiments, but various modifications may be made to the detailed configuration without departing from the spirit and scope of the present invention.

[0093]

As described above, according to the present invention, the progress of temperature versus time of a workpiece in a resonant cavity device is monitored and the progress of the radiation intensity is controlled to achieve this progress according to a predetermined schedule. At the same time as controlling the situation, the physical properties of the workpiece change as a result of the microwave irradiation, but at the same time by changing the position of the microwave source and the resonant cavity device shot relative to the workpiece, to the same resonance. The cavity device can be kept in tune, the Q of the resonant cavity device can be monitored, the temperature-Q history can be used to determine when the workpiece has reached the expected physical state, You can decide to stop. Thus, by changing the output of the microwave source based on Z over time, it is possible to easily and reliably obtain a product of a desired quality by knowing the point at which the reaction is almost accurate within the shortest time. .

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an adjustable microwave cavity processing system according to one embodiment of the present invention.

FIG. 2 is a computer controller for monitoring a microwave source, a three-port circulator, a directional coupler, a power meter, a pseudo load, a pyrometer and power output, a workpiece temperature and a Q factor of a microwave cavity, FIG. 4 is a schematic diagram illustrating connection to an adjustable microwave cavity.

FIG. 3 is a plot of microwave power (Y-axis) versus time (X-axis) applied to the resonant cavity device of FIG. 1 and plots of precursor and / or polymer temperatures obtained during that time; It is a graph at the time of applying such a microwave output twice continuously.

FIG. 4 is a graph showing the plot of reflected microwave power against the height of the cavity of the device of FIG. 1, wherein the Q factor of the system monitors the reflected microwave power from the coupling to the cavity. The reciprocal of the width at half the height of the resonance dip (for a constant frequency input) obtained by the operation.

FIG. 5 is a graph showing a plot of the electric field strength E of microwave radiation used in accordance with the present invention, the power of such radiation being directly related to the square of E, the electric field E being dissolved in the solvent. The value on the Y-axis between Emax and Emin for the polyimide precursor obtained, which can be obtained by locating where solvent can be removed without boiling, ie, without foaming. The electric field E is too small to remove the solvent and is dried, and the value Ema is such that the solvent is boiled and the polyamic acid bubbles are generated.
and these values are determined for various thicknesses "d" plotted along the X-axis.

FIG. 6 is a flow chart illustrating a portion of a control system of the present invention used in automatically controlling a microwave device according to the present invention, wherein a desired level of microwave is applied to a workpiece. Can be.

FIG. 7 is a flow chart showing a portion of a control system of the present invention used in automatically controlling a microwave device according to the present invention, applying a desired level of microwave to a workpiece. Can be.

FIG. 8 is a flow chart of the automatic adjustment subsystem of the system of FIGS. 6 and 7;

FIG. 9 is a flow chart of the temperature control subsystem of the system of FIGS. 6 and 7;

FIG. 10 is a flowchart of the diagnostic and endpoint detection subsystem of the system of FIGS. 6 and 7;

FIG. 11 is a graph showing a typical temperature-time profile, using segments to enter the desired profile into the program.

FIG. 12 is a graph showing the dependence of Q on Z and temperature.

FIG. 13 is a logical block diagram showing interconnections between tool control subroutines.

FIG. 14 is a plot of a typical Z factor versus temperature profile monitored during the curing process.

[Explanation of symbols]

2 ... adjustable microwave resonant cavity device, 4 ... cylindrical side wall, 6 ... upper wall, 9, 18 ... opening, 10 ... short plate, 11 ... sliding seal, 12 ... hole, 14 ... control rod,
16 ... plate, 20, 56, 58, 60, 62, 64, 70
... Conduit, 22 ... Binding probe, 24 ... Rack, 2
6 ... Pinion, 28, 50 ... Motor, 29 ... Nipple,
30 ... microwave processing system, 32 ... microwave source,
34 circulator, 36 connector, 38 pseudo load, 42 directional coupler, 44, 46 output meter and sensor, 48 coaxial cable or waveguide, 52 worm drive, 54 controller, 66 pyrometer , 68 ... Optical pyrometer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01P 7/06 H01P 7/06 11/00 11/00 G (72) Inventor David André Louis Lewis, Carmel 10512, New York, United States No. 451, C. Dourieville Bill (72) Inventor Jane Margaret Sillot, 336 Wilton Road West, Ritzfield, Ritzi Field, 06877, Connecticut, United States (56) References JP-A-63-15502 (JP) JP-A-58-111295 (JP, A) JP-A-55-128289 (JP, A) JP-A-48-34347 (JP, A) JP-A-2-202202 (JP, A) 49-11333 (JP, U) JP 60-28118 (JP, B2) JP 3-75084 (JP, B2) JP 3-750 83 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05B 6/68 320 H05B 6/68 310 H05B 6/80 C08G 73/10 H01P 7/06 H01P 11/00

Claims (8)

(57) [Claims] 1. A system for controlling microwave irradiation on a workpiece in a cavity, comprising: a time tracking means for tracking a current time; and a means for detecting a forward power signal indicative of the microwave irradiation intensity. Means for detecting a reflected power signal indicating the reflection intensity of the microwave; means for detecting a temperature signal indicating the temperature of the workpiece; and responsive to the detected forward power signal and the reflected power. Means for adjusting the tuning of the cavity to minimize the α value given by the reflected power intensity / forward power intensity; and responsive to the detected temperature signal, the temperature is substantially equal to a predetermined temperature. Temperature control means for controlling the irradiation intensity of the microwave so as to be equal; Q (Q is a resonance frequency and a half of the resonance output) for the workpiece; Means for checking a current value of the frequency width) and means for determining whether the workpiece has reached a predetermined physical state from the current value of the Q and the current value of the temperature, Means for generating an end signal that terminates operation of the system when the workpiece reaches the predetermined final physical state. And means for generating a signal corresponding to the forward irradiation intensity, a signal corresponding to the reflection intensity, and a signal corresponding to the temperature for visual display on a visual display means. The radiation control system according to claim 1, characterized in that: 3. The cavity comprises a short and a microwave probe movable within the cavity, wherein the means for adjusting the tuning of the cavity comprises: means for receiving a signal indicating the α value; and a signal indicating the α value. Means for transmitting a position control signal for moving one of said microwave probe or said short circuit until said α value reaches a minimum in response to the radiation. Control system. 4. The temperature control means for controlling the temperature to substantially match a predetermined temperature versus time schedule generates a temperature hold signal 200 when the temperature is to be held constant as per the schedule. Temperature holding determining means 198 for generating a temperature test signal 226 when the temperature is not to be held constant as per the schedule; and receiving the temperature test signal 226 and setting the current temperature to the next hold temperature by the schedule. A temperature test means 228 for generating a temperature duration signal 230 if the current temperature is not greater than the next holding temperature, and a heating rate confirmation signal 252 if the current temperature is not greater than the next holding temperature; Receiving means for generating a signal indicating a temperature holding state; and receiving and opening the signal indicating the temperature holding state. Means 236 for generating a time recording signal; when the start time recording signal is received and the temperature holding signal is received and the current time is within the area of the schedule indicating that the temperature is to be kept constant. Generates a temperature holding continuation signal 240, and when the current time is in the area of the schedule indicating that the temperature is not held constant, the temperature holding non-continuation signal 208
Receiving the temperature holding continuation signal, and when the temperature is different from the temperature indicated by the schedule with respect to the current time, generating a temperature different from a desired signal; Means 242 for generating a temperature which is not different from the desired signal when the temperature is not different from the desired signal; and means for receiving the temperature different from the desired signal and when the temperature is lower than the temperature indicated by the scheduler. Means for generating a temperature equal to the desired signal by increasing the intensity and decreasing the intensity when the temperature is higher than the temperature indicated by the scheduler; and receiving the heating rate confirmation signal. Means 254 for generating a temperature rate comparison signal by confirming the current heating rate; and receiving the temperature rate comparison signal and receiving the temperature rate comparison signal. When the temperature rate is approximately equal to the temperature rate indicated by the schedule for the current time, a temperature rate 260 equal to the expected signal is generated, wherein the temperature rate is relative to the current time. Means 258 for generating a temperature rate 262 which is not equal to the expected signal when not equal to the temperature rate indicated by the schedule; and receiving said temperature rate which is not equal to the expected signal, and If the heating time is less than the heating rate instructed by the schedule, a signal instructing to increase the temperature is generated, and the heating rate is increased by the schedule with respect to the current time. If the heating rate is greater than the commanded heating rate, a signal is issued instructing to decrease the temperature, and the temperature rate is changed to the current rate. Means 264 for generating a second temperature rate equal to the expected signal when the temperature rate is substantially equal to the temperature rate indicated by the schedule for the current time; and when the current time is the end time of the schedule. It is confirmed that the current time is smaller than the end time by receiving the temperature equal to the desired signal, receiving the temperature not different from the desired signal, and receiving the temperature holding non-continuation signal. 2. The radiation control system according to claim 1, further comprising means for generating a schedule end signal when not present, and generating a schedule non-end signal when the current time is less than the end time. 5. The method of claim 1, wherein the means for determining when the workpiece has reached a predetermined final physical state comprises: generating a signal that places the α value in a non-minimized state. The α value is minimized by means for confirming the current value of Q (Q is the ratio of the resonance frequency to the frequency width at half the resonance output) for the piece and means for adjusting the tuning state of the cavity. And means for determining whether the workpiece has reached the predetermined physical state from the current value of Q and the current temperature. 3. The radiation control system according to claim 1. 6. The means for adjusting the tuning of the cavity comprises: generating a signal to modify the cavity to produce a signal for modifying the α.
Means for changing the value, means for checking whether the α value is increasing or decreasing in response to the signal for changing the α value, and means for checking whether the α value is increasing or decreasing. By generating a signal based on the above confirmation of what is going on,
Means for modifying the cavity to minimize the α value, wherein the temperature control means receives a particular temperature value of the temperature signal corresponding to a particular time value of the current time; Means for generating a heating rate signal from the specific temperature value and the specific time value based on the confirmation of the speed, and a comparison signal based on a comparison between the heating rate signal and the predetermined temperature versus time schedule. Generating means for generating a signal that corrects the forward power in response to the comparison signal, the means for determining when the workpiece has reached a predetermined final physical state. Means for confirming the current Q (Q is the ratio of the resonance frequency to the frequency width at half of the resonance output) for the cavity, and a Q that defines the current Q and the current temperature in advance. as well as Means for comparing temperature to a measure of a physical state schedule of the workpiece. 7. A method for controlling microwave irradiation on a workpiece within a cavity, the method comprising: tracking a current time; and detecting a forward power signal indicative of the microwave irradiation intensity. Detecting a reflected power signal indicating the reflected intensity of the microwave; detecting a temperature signal indicating the temperature of the workpiece; responding to the detected forward power signal and the reflected power. Adjusting the tuning of the cavity to minimize the α value given by the reflected power intensity / forward power intensity; responsive to the detected temperature signal, the temperature is substantially equal to a predetermined temperature. A temperature control step of controlling the irradiation intensity of the microwave so as to be equal, and Q (Q is a resonance frequency, Checking the current value of the Q value and the current value of the temperature to determine whether the workpiece has reached a predetermined physical state. And generating an end signal that terminates operation of the system when the workpiece reaches the predetermined final physical state. 8. The step of adjusting the tuning state of the cavity, the step of modifying the cavity to change the α value, and the step of increasing the α value based on the modification of the α value. And a step of minimizing the α value by modifying the cavity, wherein the step of controlling the current temperature corresponds to a specific time value. A step of monitoring a specific temperature value to be performed, a step of confirming a heating rate from the specific temperature value and the specific time value, and a step of comparing the heating rate with the predetermined temperature versus time schedule. Modifying the forward power based on the comparison to determine when the workpiece has reached a predetermined final physical state. Checking the current Q (where Q is the ratio of the resonance frequency to the frequency width at half the resonance output) for the cavity; and determining the current Q and the current temperature with predetermined Q and 8. A method according to claim 7, comprising the steps of comparing the temperature versus the physical state schedule of the workpiece and comparing.