TECHNICAL FIELD

[0001] This disclosure relates to furnaces, and more particularly, to furnaces that are used to process co-fired ceramic devices.

BACKGROUND

[0002] Co-fired ceramic devices are fabricated in a multilayer structure. The co-fired device fabricating process starts from producing composite tapes, consisting of ceramic particles mixed with bonders. Electrical components (such as capacitors, resistances, inductors, resonators, filters, etc.) are formed on individual layers of the composite tapes and multilayers of composite tapes are then attacked and bounded together. The composite tapes are flexible and can be cut into many component-pieces, which are placed on supporting structures. The component-pieces and their supporting structures are co-fired in a furnace to form co-fired ceramic devices. The co-fired device fabricating process can be also used to produce Hybrid Circuit Board.

[0003] Co-firing can be classified into two applications: Low Temperature Ceramic Devices (LTCC) application and High Temperature Ceramic Devices (HCTC) application, where low temperature means that the sintering temperature is below 1000 degree Celsius while high temperature is around 1600 degree Celsius.

SUMMARY

[0004] The first aspect of this disclosure relates to a furnace comprising a furnace chamber, a convey belt and a plurality of upper infrared means. The convey belt is installed inside of the furnace chamber, for carrying and moving the co-fired ceramic devices through the furnace chamber. The plurality of upper infrared means are arranged above the convey belt. The furnace chamber is configured to perform either one of the two following processes:(l)providing heating to remove binder-materials from co-fired ceramic devices; or(2)providing heating to form co-fired ceramic devices into a monolithic sintered mass structure.

[0005] As for the furnace mentioned above in the first aspect, wherein the plurality of upper infrared means generates heats inside the furnace chamber.

[0006] As for the furnace mentioned above in the first aspect, the furnace further comprises a plurality of bottom infrared means projects infrared lights. The plurality of bottom infrared means projects infrared lights onto the co-fired ceramic devices when the ceramic devices are moving through the furnace chamber.

[0007] As for the furnace mentioned above in the first aspect, the furnace further comprises a plurality of bottom coils that are arranged below the convey belt. The plurality of bottom coils generates heats inside the furnace chamber.

[0008] As for the furnace mentioned above in the first aspect, the plurality of upper infrared means are plurality of upper infrared lamp tubes.

[0009] As for the furnace mentioned above in the first aspect, the plurality of bottom infrared means are plurality of bottom infrared lamp tubes.

[0010] As for the furnace mentioned above in the first aspect, the convey belt is configured to carry at least one supporting means to accommodate the co-fired ceramic devices thereon inside the furnace chamber.

[0011] As for the furnace mentioned above in the first aspect, the at least one supporting means is manufactured by using a material that allows infrared light to pass through.

[0012] As for the furnace mentioned above in the first aspect, the furnace chamber includes a plurality of heating zones.

[0013] As for the furnace mentioned above in the first aspect, the furnace further comprises a plurality of zone dividers to divide the furnace chamber into a plurality of heating zones.

[0014] As for the furnace mentioned above in the first aspect, each of the plurality of zone dividers having an upper section and a bottom section so that when the upper section and the bottom section are put together, a gap is informed between the upper section and the bottom section. The upper section and the bottom section have substantially even distributed small holes over the two sections so that these holes allow the compressed air (or gas) to move through, but separate the plurality of heating zones from each other so as to improve temperature uniformity among the plurality of heating zones.

[0015] As for the furnace mentioned above in the first aspect, in a process of providing heating to form the co-fired ceramic devices into a monolithic sintered mass structure, the temperature inside the furnace chamber is between 0 degree Celsius and 900 degree Celsius. [0016] As for the furnace mentioned above in the first aspect, the furnace further comprises an entry section that is located before the furnace chamber; and an exiting section that is located after the furnace chamber.

[0017] The second aspect of this disclosure relates to a furnace system for processing co-fired ceramic devices. The furnace system comprises a furnace chamber, a convey belt and a plurality of upper infrared means. The convey belt is installed inside of the furnace chamber, for carrying and moving the co-fired ceramic devices inside of the furnace chamber. The plurality of upper infrared means are arranged above the convey belt. The at least one supporting means is used accommodate the co-fired ceramic devices thereon inside the furnace chamber. The plurality of upper infrared means generates heat inside the furnace chamber and projects infrared lights onto the co-fired ceramic devices when the ceramic devices are moving through the furnace chamber.

[0018] As for the furnace system mentioned above in the second aspect, the furnace system further comprises a plurality of bottom infrared means that are arranged below the convey belt. The plurality of bottom infrared means generates heat inside the furnace chamber.

[0019] As for the furnace system mentioned above in the second aspect, the plurality of bottom infrared means projects infrared lights onto the co-fired ceramic devices when the ceramic devices are moving through the furnace chamber.

[0020] As for the furnace system mentioned above in the second aspect, the furnace system further comprises a plurality of bottom coils that are arranged below the convey belt. The plurality of bottom coils generates heat inside the furnace chamber.

[0021] As for the furnace system mentioned above in the second aspect, the at least one supporting means is manufactured by using a material that is transparent to infrared light.

[0022] The furnaces and the furnace system includes advantageous technical effects as follows:

[0023] 1, The furnaces and the furnace system are able to be used both for bonder removing cycle and for co-fired sintering cycle;

[0024] 2, The furnaces and the furnace system have improved heating uniformity especially in temperature increasing stage so as to increase temperature increasing velocity; [0025] 3, The furnaces and the furnace system are able to project infrared lights on the ceramic devices in process to improve temperature uniformity;

[0026] 4, One type of heating means (such as infrared lamps) is used in the furnace to simple the heating structure of the furnace;

[0027] 5, Ventilating zone dividers are set between the heating zones, so that the heating uniformity of each heating zone is better.

[0028] Due to the above advanced technical effects, the sintering furnace of the application has special advantages for processing low-temperature ceramic device (LTCC).

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention will be more fully described in the following detailed description in conjunction with the drawings in which the same or similar components use same reference numbers as follows:

[0030] Figure 1 is an exemplary block diagram of a furnace in accordance with the present disclosure.

[0031] Figure 2 depicts a perspective view of the furnace shown in Figure 1.

[0032] Figures 3A-3C depict three section views of the furnace cutting along line A-A in

Figure 2, showing three embodiments of the furnace 100, respectively.

[0033] Figures 4A-4C depict the details in the furnace chamber according to the three embodiments shown in Figures 3A-3C, respectively.

[0034] Figures 5A-5B are the top sectional view and the bottom sectional view of the furnace shown in Figure 3A.

[0035] Figure 6A depicts a tray that is used to retain ceramic devices to be processed in the furnace in a bonder removing cycle or in a co-fired sintering cycle.

[0036] Figures 6B-6C depict a heating zone divider in the furnace chamber.

[0037] Figures 7A-7B show a thermal profile in a bonder removing cycle and a thermal profile in a co-fired sintering cycle, respectively. [0038] Figure 8 shows that a plurality of supporting means, such as trays, are placed in the furnace chamber shown in Figure 4A.

[0039] Figure 9 depicts a block diagram of the controller as shown in Figure 1.

[0040] Figure 10 depicts a flowchart to operate the furnace of the present disclosure.

DETAILED DESCRIPTION

[0041] Figure 1 is an exemplary block diagram of a furnace 100 in accordance with the present disclosure. As shown in Figure 1, the furnace 100 comprises a furnace housing 102, a furnace entrance 101 (i.e. an entry section) that is connected to an entrance opening 122 of the furnace housing 102 and furnace exit 103 (i.e. an entry section) that is connected to an exit opening 124 of the furnace housing 102. There are three exhaust ducts 116.1, 116.2, 116.3 on the upper-wall 144 of the furnace housing 102 and there are three exhaust openings 117.1, 117.2 and 117.3 on the top of the three exhaust ducts 116.1, 116.2, 116.3 respectively. There are also two exhaust openings 119.1 and 119.2 on the up-wall 144 of the furnace housing 102. In Figure 1, the furnace 100 has a housing bottom wall 145.

[0042] In Figure 1, the furnace housing 102 accommodates a furnace chamber 142, a pipe assembly 108 and an air meter 104. The furnace chamber 142 accommodates a heating source 152 that provides heats to a plurality of heating zones (shown in Figures 4A-4C) inside the furnace chamber 142 and heating sensors 154 for measuring the current temperatures in the plurality of heating zones. The exhaust openings 117.1, 117.2, 117.3 are used to release the used air (or gas) from the furnace chamber 142 and the exhaust openings 119.1 and 119.2 are used to release the air from the furnace housing 102.

[0043] The air meter 104 is connected to an outside air source 106 and a controller 112. The heating source 152 is connected to the controller 112 so that the controller 112 can control the heating source 152 to set suitable thermal profiles in the plurality of the heating zones for co-fired processing. Based on the temperature feedbacks from the heating sensors 154, the controller 112 adjusts the temperatures in the plurality of heating zones in compliance with the suitable thermal profiles. The air source 106 provides circulation air (or circulation gas) (such as compressed air) to the furnace chamber 142 via air meter 104 and pipe assembly 108. Under the control of controller 112, the air meter 104 regulates the amounts and speeds of the compressed air that passes through the pipe assembly 108. The compressed air from the air source 106 enters the furnace chamber 142 via the pipe assembly 108. The compressed air can enhance the temperature uniformity in the furnace chamber 124 and the amounts and speeds of the compressed air are determined by the parameters of the ceramic devices to be processed, such as mass and thickness of the ceramic devices to be processed.

[0044] In the present disclosure, by suitably selecting the heating means for the furnace chamber 142 and designing the structure for the furnace 100, the furnace 100 of the present disclosure can be used for both bonder removing cycle (or process) and for co-fired sintering cycle (or process). Because the processing times in a bonder removing cycle can vary greatly from that in a co-fired sintering cycle. By being able to be used both for bonder removing cycle and for co fired sintering cycle, the furnace 100 in the present disclosure can be operated more efficiently than existing furnaces.

[0045] In a bonder removing cycle, the controller 112 first sets the heating source 152 in accordance with a pre-designed thermal profile that is suitable for removing bonder materials in the to-be-processed raw ceramic devices. The raw ceramic devices are fed into the entrance opening 122 of the furnace chamber 142 via the furnace entrance 101 and are carried and moved through the furnace chamber 142 to reach the ending opening 124 of the furnace chamber 142. After the raw ceramic devices have been moved through the furnace chamber 142, the bonder materials are removed from the raw ceramic devices so that they are ready to be processed in a subsequent co-fired sintering cycle. At this time, the furnace exit 103 moves these bonder-material- free ceramic devices out of the furnace chamber 142.

[0046] In the co-fired sintering cycle, the controller 112 first sets the heating source 152 in accordance with a pre-designed thermal profile that is suitable for co-firing the bonder-material- free ceramic devices. The bonder- material-free ceramic devices are fed into the entrance opening 122 of the furnace chamber 142 via the furnace entrance 101 and are carried and moved through the furnace chamber 142 until reaching the ending opening 124 of the furnace chamber 142. After the bonder-material-free ceramic devices have been moved through the furnace chamber 142, they become final co-fired ceramic devices. At this time, the furnace exit 103 moves the final co-fired ceramic devices out of the furnace chamber 142. [0047] Figure 2 depicts a perspective view of the furnace 100 shown in Figure 1. As shown in Figure 2, in additional to all the other components as shown in Figure 1, the furnace housing 102 includes a housing front wall 202. In Figure 2, the controller 112 is installed on the housing front wall 202 and includes a screen 204 and a keyboard 206. The furnace housing 102 also includes a housing bottom-wall and a housing back-wall, which are not shown in Figure 2.

[0048] Figures 3A-3C depict three section views of the furnace 100 cutting along line A-A in Figure 2, showing three embodiments of the furnace 100, respectively.

[0049] As shown in Figure 3A-3C, the furnace chamber 142 has a chamber upper-wall 302 and chamber bottom-wall 304, where a heating space 308 is formed between the chamber upper- wall 302 and the chamber bottom-wall 304. The furnace chamber 142 has an entrance opening 122 and an exit opening 124. A convey belt 306 circularly moves through and around the furnace chamber 142 to carry and move ceramic devices from the entrance opening 122 to the exit opening 124. The convey belt 306 in the furnace chamber 142 divides the hearing space 308 into an upper heating space 308.1 and a bottom heating space 308.2. Three fans 309.1, 309.2 and 309.3 are installed inside of the three exhaust ducts 116.1, 116.2, 116.3 respectively, and connected with the heating space 308. The air (or gas) source 106 sends compressed air (or compressed gas) into the furnace chamber 142 via the pipe assembly 108. The fans 309.1, 309.2 and 309.3 drives the compressed air to circulate the compressed air within the furnace chamber 142 and drives the compressed air out of the furnace chamber 142 through the three exhaust ducts 116.1, 116.2, 116.3. The air circulation can improve the temperature uniformity within the heating space 308.

[0050] In Figures 3A-3C, a master wheel 318, which is driven by a motor (shown in Figure 9), drives the convey belt 306. Six supporting wheels 321, 322, 323, 324, 325, 326 support the convey belt 306 when the convey belt 306 is driving by the motor and moving through and around the furnace entrance 101, the heating space 308 and the furnace exit 103. The controller 112, which is shown in Figure 9, controls the motor 962.

[0051] According to the first embodiment as shown in Figure 3 A, the upper infrared means 312 are installed in the upper heating space 308 and bottom infrared means 313 are installed in the bottom heating space 308.2. More details of the upper infrared means 312 and bottom infrared means 313 will be described below in connection with Figure 4A. [0052] As shown in Figure 3B, the structure of the second embodiment is similar to that shown in Figure 3A. In Figure 3B, like the structure in Figure 3A, the upper infrared means 312 are installed in the upper heating space 308.1. However, in Figure 3B, the bottom heating means are bottom coil means 317 that are installed in the bottom heating space 308.2. More details of the upper infrared means and bottom coil means will be described below in connection with Figure 4B.

[0053] As shown in Figure 3C, the structure of the third embodiment is similar to that shown in Figure 3A. In Figure 3C, like the structure in Figure 3A, the upper infrared means 312 are installed in the upper heating space 308.1. However, in Figure 3C, there are no heating means in the bottom heating space 308.2. More details of the upper infrared means will be described below in connection with Figure 4C.

[0054] Figures 4A-4C depict the details in the furnace chamber 142 according to the three embodiments shown in Figures 3A-3C, respectively.

[0055] As shown in Figure 4A, the first embodiment of the furnace chamber 142 has nine heating zones 402.1, 402.2, 402.3, 402.4,..., 402.9 and the eight zone dividers 411, 412, ..., 418. The zone dividers can prevent the heats in nine heating zones from interfering each other, thus can better keep temperature uniformity in each of the nine heating zones. In each of the nine heating zones, the upper infrared means 312 includes four sets of the upper infrared lamps (411.1, 411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2, 419.3, 419.4) that are installed above the convey belt 306 and the bottom infrared means 313 includes four sets of bottom infrared lamps (421.1, 421.2, 421.3, 421.4; 422.1, 422.2, 422.3, 422.4; ..., or 429.1, 429.2, 429.3, 429.4) that are installed below the convey belt 306. The five heating zones 402.1, 402.2, 402.3, 402.4 and 402.9 have about the same zone length (1100mm for example), the four heating zones 402.5, 402.6, 402.7, 402.8 have about the same zone length (860mm for example). Because the zone length of the four heating zones 402.5, 402.6, 402.7, 402.8 are shorter than that of the five heating zones 402.1, 402.2, 402.3, 402.4, 402.9, with the same heating sources, the shorter heating zones can provide heat more intensive than the five longer heating zones can. The individual pipes in the pipe assembly 108 are connected through to each of the nine heating zones through the chamber upper-wall 302 and the chamber bottom-wall 304. [0056] As shown in Figure 4B, the second embodiment of the furnace chamber 142 has a structure similar to that in the first embodiment as shown in Figure 4A. In Figure 4B, like the structure shown in Figure 4A, in each of the nine heating zones, the upper infrared means 312 includes four sets of the upper infrared lamps (411.1, 411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2, 419.3, 419.4) that are installed above the convey belt 306. However, in each of the nine heating zones, the bottom coil means 317 includes four sets of coil means (such as coil wires) (431.1, 431.2, 431.3, 431.4; 432.1, 432.2, 432.3, 432.4; ..., or 439.1, 439.2, 439.3, 439.4) that are installed below the convey belt 306.

[0057] As shown in Figure 4C, the third embodiment of the furnace chamber 142 has a structure that is similar to that in the first embodiment as shown in Figure 4A. In Figure 4C, like the structure shown in Figure 4A, the upper infrared means 312 includes four sets of the upper infrared lamps 411.1, 411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2, 419.3, 419.4 that are installed above the convey belt 306. However, there are no heating means that are installed in the bottom heating space 308.2 below the convey belt 306.

[0058] Figures 5A-5B are the top sectional view and the bottom sectional view of the furnace 100 shown in Figure 3 A, illustrating the arrangement of the four sets of upper infrared lamps 411.1,

411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2, 419.3, 419.4 and the four bottom sets of infrared lamps 421.1, 421.2, 421.3, 421.4; 422.1, 422.2, 422.3, 422.4; ..., or 429.1,

429.2, 429.3, 429.4 in the furnace chamber 142.

[0059] As shown in Figure 5A, the four sets of the upper infrared lamps 411.1, 411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2, 419.3, 419.4 are infrared lamp tubes installed on the upper wall 302 in the heating space 308 along the width direction of the furnace chamber 142. As shown in Figure 5B, the four sets of the bottom infrared lamps 421.1, 421.2,

421.3, 421.4; 422.1, 422.2, 422.3, 422.4; ..., or 429.1, 429.2, 429.3, 429.4 are infrared lamp tubes installed on the chamber bottom wall 304 in the heating space 308 along the width direction of the furnace chamber.

[0060] It should be understood that the person skilled in the art can install the four sets of the upper infrared lamps (411.1, 411.2, 411.3, 411.4; 412.1, 412.2, 412.3, 412.4; ..., or 419.1, 419.2,

419.3, 419.4) in Figures 4B-4C according to the structures shown in Figure 5A. [0061] Figure 6A depicts a tray 602 that is used to retain ceramic devices to be processed in the furnace 100 in a bonder removing cycle or in a co-fired sintering cycle. Co-fired ceramic devices are usually small in size. For example, the lengths, widths and heights of three particular co-fired ceramic devices of three are 1.85mmx0.9mmx0.4mm, 1.97mmx0.96mmx0.70mm; and 1.88mmx0.98mmx0.7mm, respectively. As shown in Fig. 6A, the tray 602 has a tray bottom 604 and four tray walls 606.1, 606.2, 606.3 and 606.4 extending upward from the four edges of the tray bottom.

[0062] Therefore, when moving through the furnace chamber 142, the ceramic devices needs to be retained in supporting means such as tray which may have multiple compartments for retaining (or carrying) many individual ceramic devices. As shown in Figure 6 A, the tray 602 includes a bottom 604 and four walls that extend from the four edges from the tray 602. The tray can be stacked in several layers so that a large quantity of ceramic devices can be processed in one cycle. The supporting means can be other types such as rack.

[0063] Through observation and analysis, the inventors realize that even with effective air circulation in furnace chamber, an existing furnace may have difficulty to uniformly project heat on ceramic devices in processing, especially when increasing temperature, to enable its heat to uniformly impact on ceramic devices in process. Therefore, the existing furnace may need to slow down the speed in temperature increasing stage and may need to keep the ceramic devices in the furnace a longer time, thus resulting that the ceramic devices in process stay a longer time in the furnace chamber. Additionally, due to the impact of the supporting means (such as tray 602), the existing furnace may have difficulty to uniformly project heat on ceramic devices in processing.

[0064] By contrast, via experiment and simulation, the infrared means used in the present disclosure can provide improved heating uniformity to the ceramic devices in processing, even with the impact of supporting means in furnace chamber 142, especially when in the temperature increasing stage, the infrared means in the present disclosure can still provide improved heating unity. Thus, the furnace 100 in the present disclosure has faster production cycles than existing furnace for producing co-fired ceramic devices.

[0065] Figure 6B depict sectional view along the line B-B in Figure 2, showing one of the eight zone dividers 411, 412, ..., 418 in the furnace chamber 124. Figure 6C shows the structure of the dividers in detail. [0066] As shown in Figure 6B, the furnace 100 has two convey lanes and each of the convey lanes has two zone dividers D1 and D2. In the middle position on each of the D1 and D2, there is a gap G1 or G2 to allow the convey belt 306 and tray 602 to pass through.

[0067] As shown in Figure 6C, each of the two zone dividers D1 and D2 has a upper section 614 and a bottom section 616. There is a cavity 628 at the bottom edge of the upper section 614 so that when the upper section 614 and the bottom section 616 are put together, the gap G1 or G2 as shown in Figure 6B is formed between the upper section 614 and the bottom section 616. Also as shown in Figure 6C, the upper section 614 and the bottom section 616 have small holes substantially even distributed over the two sections so that these holes (black dots as shown in Figure 6C) to allow the compressed air to move through nine heating zones, but separate the nine heating zones from each other so as to reduce the influence of temperature change between heating sections and to improve temperature uniformity among these nine heating zones.

[0068] Figures 7A-7B show a thermal profile in a bonder removing cycle and a thermal profile in a co-fired sintering cycle, respectively.

[0069] As shown in Figures 7 A, in a bonder removing cycle, the vertical coordinate indicates temperature arranging 0-400 degree Celsius; the top coordinate indicates heating zones (#1 , #2,

... , #9); the bottom coordinate indicates the total time intervals in which a batch of ceramic devices are being moved through all nine heating zones. As shown in Figure 7A, the bonder removing cycle can be completed within 480 minutes in the furnace 100 due to improved heating uniformity.

[0070] Similarly, as shown in Figures 7B, the vertical coordinate indicates temperature arranging 0-900 degree Celsius; the upper coordinate indicates heating zones (#1, #2, ..., #9); the bottom coordinate indicates the total time intervals in which a batch of ceramic devices are being moved through all nine heating zones. As shown in Figure 7 A, the co-fired sintering cycle can be completed within 480 minutes in the furnace 100 with improved yield due to improved heating uniformity.

[0071] Figure 8 shows that a plurality of supporting means, such as trays 602, are placed in the furnace chamber 142 shown in Figure 4A. A plurality of supporting means, such as trays 602, are placed in the furnace chamber 142 to form a furnace system with the furnace. As shown in Figure 8, in a bonder removing cycle or in a device co-firing cycle, the ceramic devices are retained in the trays 602 and moved through the nine heating zones. The infrared heating means (such infrared lamp tubes) provide heats to heat the environment of the furnace chamber 142. In the meantime the upper infrared heating means project infrared lights onto the upper surfaces of the ceramic devices. Because the ceramic devices are heated both by the heat in the furnace environment and by the infrared lights projected onto the upper surface of the ceramic devices, the heating uniformity is improved especially at the time when the heating temperatures are in increasing. Furthermore, if the trays are made by using the material that allows infrared lights to pass through (such as quartz), the bottom infrared means can also project infrared lights onto the bottom surface of the ceramic devices, thus further improving the uniformity of heating inside of the furnace chamber 142.

[0072] Figure 9 depicts a block diagram of the controller 112 as shown in Figure 1. As shown in Figure 9, the controller 112 includes a bus 902. Connected to the bus 902 are a processor 903, a memory 904, a mass storage 905, an input interface 906, and an output interface 907. The processor 903 can read out the programs (or instructions) from the memory 904 or mass storage 905 and execute the program (or instructions) to perform the control functions to the furnace 100; the processor 903 can also write data or instructions into the memory 904 or mass storage 905. The memory 904 and mass storage 905 can store programs (instructions) or data. Usually, the memory 904 has an access speed faster than that of the mass storage 905 while the mass storage has a memory size larger than that of the memory 904. By executing the instructions in the memory 904, the processor can control the memory 904, the mass storage 905, the input interface 906, and the output interface 907.

[0073] The input interface 906 receives inputs from peripheral devices (such as keyboard 206, heating sensors 154) and transforms the received inputs from the peripheral devices into the signals that are recognizable by the processor 903. In Figure 9, the input interface 906 is connected to the heating sensor 154 via link 921 and to the keyboard 206 via link 922.

[0074] The output interface receives control signals from the processor 903 and transforms them into outputs that are suitable for driving peripheral devices (such as the screen 204, heating source 152, motor 962 which is used to drive the master wheel 318 in Figures 3A-3C).

[0075] In operation, when receiving the transformed inputs from the keyboard 206, the processor 903 performs the needed functions according to the inputs from the keyboard 206; when receiving the transformed inputs from the heating sensor 154, the processor 903 controls the heating means in the heating source 152 so that the heating zones in the furnace chamber 142 is suitable temperatures.

[0076] Also in operation, when receiving the control signals from the processor 903, the output interface 907 transforms the control signal into outputs and uses the transformed outputs to the switches in the air meter 104, to the heating source 152 to control/adjust the temperatures of the heating source 152, to the screen 204 to display user information on thereon, and to motor 963 to control the rotation speed of the master wheel 318.

[0077] Figure 10 depicts a flowchart 1000 to operate the furnace 100 of the present disclosure.

[0078] Before operating the furnace 100, the user inputs operation parameters into the controller 112 via the key board 206 and the screen 204.

[0079] In the step 1004, based on the operation parameters, the controller 112 determines whether the operation is in a bonder removing cycle or is in a co-firing sintering cycle.

[0080] If the operation is in the bonder removing cycle, the operation is led to step 1005 to set a thermal profile suitable for bonder removing and the operation is then led to step 1008.

[0081] If the operation is in the co-firing sintering cycle, the operation is led to step 1006 to set a thermal profile suitable for the co-firing sintering cycle and the operation is then led to step 1008.

[0082] In step 1008, the controller 112 activates the heating means as shown in Figures 3A- 3B according to the input of the thermal profile.

[0083] In step 1010, the controller 112 activates the convey means as shown in Figures 3A- 3B according to the input of the thermal profile.

[0084] In step 1012, the controller 112 activates the air meter 104 as shown in Figure 1 according to the input of the thermal profile.

[0085] In step 1014, after the ceramic devices to be processed are placed on the supporting means such as the tray 602 in Figure 6A, the controller 112 controls the loading of the supporting means into the furnace chamber 142 through furnace entrance 101 as shown in Figure 1. [0086] In step 1016, the controller 112 controls the on/off and speed of rotation of the convey belt 306 through controlling motor 962 as shown in Figures 3A-3C to move the ceramic devices through the nine heating zones as shown in Figures 3A-3C.

[0087] In step 1018, when needed, according to the feedbacks from the heating sensor 154 shown in Figure 1, the controller 112 adjusts the heats generated by the heating means shown in Figures 3A-3C in compliance with the input of the thermal profile.

[0088] In step 1020, after completion of the bonder removing cycle or the co-firing sintering cycle, the controller 112 controls rotation of the convey belt 306 to output the ceramic devices via the furnace exit 103 as shown in Figure 1.

[0089] In the step 1022, the controller 112 determines whether the operation needs to be continued.

[0090] If the operation does not need to be continued, the operation is led to step 1022 to end the operation.

[0091] If the operation needs to be continued, the operation is led to step 1004 to start a new processing cycle.

[0092] The flowchart program shown in FIG. 10 may be stored in the memory 904 of Fig. 9, the controller 112 controls the operation shown in Figure 10 by executing the program stored in memory 904 shown in Figure 9.

[0093] The embodiments in the present disclosure includes advantageous technical effects as follows:

[0094] 1 , being able to be used both for bonder removing cycle and for co-fired sintering cycle;

[0095] 2, having improved heating uniformity especially in temperature increasing stage so as to increase temperature increasing velocity;

[0096] 3, being able to project infrared lights on the ceramic devices in process to improve temperature uniformity;

[0097] 4, using one type of heating means (such as infrared lamps) in the furnace to simple the heating structure of the furnace. [0098] 5, Ventilating zone dividers are set between the heating zones, so that the heating uniformity of each heating zone is better.

[0099] Due to the above advanced technical effects, the sintering furnace of the application has special advantages for processing low-temperature ceramic device (LTCC).

[00100] While the present disclosure has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Furthermore, the technical effects and/or technical problems in the specification are exemplary and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems. Accordingly, the examples of embodiments of the present disclosure, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the invention. Therefore, the present disclosure is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents.