CN210435361U - Sintering furnace - Google Patents

Abstract

The embodiment of the application provides a sintering furnace, and the sintering furnace comprises an air inlet pipeline, a gas circulating pump, a gas heater, a sintering cavity, a condenser and a vacuum pump set. The air inlet pipeline is communicated with the input end of the gas circulating pump; the output end of the gas circulating pump is communicated with the input end of the gas heater; the output end of the gas heater is communicated with the gas inlet of the sintering cavity; the air outlet of the sintering cavity is communicated with the input end of the condenser; the output end of the condenser is communicated with the input end of the gas circulating pump; the vacuum pump set is communicated with the sintering cavity. According to the method, the technical process of removing the adhesive and the sintering technical process are completed in the same device, so that the oxygen contact risk caused by migration of the tantalum capacitor between different technologies is avoided, the content of oxygen impurities generated by the tantalum material is reduced, the quality and yield of the tantalum capacitor are improved, two technical processes are not required to be carried out independently, the migration time is saved, and the production efficiency is improved.

Description

Sintering furnace

Technical Field

The application relates to the technical field of sintering equipment, in particular to a sintering furnace.

Background

Valve metal powders are often used as the anode agglomeration powder for capacitors. The most common valve metal material is tantalum, and the capacitor with tantalum as the anode is called tantalum capacitor. In the manufacturing process of the tantalum capacitor, the anode tantalum block is formed by pressing powder and then sintering. Chemical binders are added during powder compaction and the chemical impurities of the binders have a significant impact on capacitor electrical performance and reliability during sintering. Therefore, the process of removing the binder from the tantalum block needs to be completed before sintering the tantalum block anode. In the conventional process, the process of removing the binder from the tantalum block is completed in a special device, and the tantalum block after removing the binder needs to be taken out of the device for removing the binder and placed in a sintering furnace to complete the sintering process. During the transfer of the tantalum mass, oxygen impurities in the tantalum material may be generated as a result of oxygen uptake.

Oxygen enrichment of tantalum capacitors during production and processing is caused by that most oxygen elements are adsorbed on the surface of valve metal powder particles (high-concentration oxide layer), and oxygen ions are also migrated to the interior of the particles along with the increase of temperature, so that oxygen pollution of the valve metal powder is caused. When the anode is formed, the natural oxide with a crystal structure can serve as an effective crystal nucleus under the action of temperature and field intensity, and the natural oxide continues to grow on the amorphous dielectric layer substrate to damage the dielectric layer, so that the leakage current and the reliability of the capacitor can be seriously influenced. In the subsequent molding and aging process, the damage to the defects of the dielectric layer is aggravated due to the impact of thermal stress and an electric field, so that the capacitor is failed or broken down, and the yield and the quality of the product are reduced.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a sintering furnace, which can prevent oxygen impurities from being generated in a tantalum material, thereby improving the yield of products and the quality of the products.

In a first aspect, an embodiment of the present application provides a sintering furnace, which includes an air inlet pipeline, a gas circulation pump, a gas heater, a sintering cavity, a condenser and a vacuum pump set; the air inlet pipeline is communicated with the input end of the gas circulating pump; the gas inlet pipeline is used for charging gas to the gas circulating pump so as to input the gas into the gas heater through the gas circulating pump; the output end of the gas circulating pump is communicated with the input end of the gas heater; the gas circulating pump is used for introducing heated gas into the sintering cavity and flowing the heated gas through the surface of the tantalum capacitor in the sintering cavity when the gas circulating pump is started, so that the adhesive in the tantalum capacitor is taken away by high-temperature gas and then flows into the condenser; the output end of the gas heater is communicated with the gas inlet of the sintering cavity; the gas heater is used for heating the gas entering the sintering chamber and inputting the heated gas into the sintering chamber; the air outlet of the sintering cavity is communicated with the input end of the condenser; the sintering cavity is used for carrying out vacuum high-temperature sintering on the tantalum capacitor after the adhesive is removed; the output end of the condenser is communicated with the input end of the gas circulating pump; the condenser is used for condensing the adhesive carried by the gas in the condenser, outputting the cooled gas to the gas circulating pump for gas circulation and cooling the high-temperature gas flowing out of the sintering cavity after the sintering of the sintering furnace is finished; the vacuum pump set is communicated with the sintering cavity; the vacuum pump set is used for vacuumizing the sintering cavity.

In the implementation process, the technical process of removing the adhesive and the sintering technical process of the tantalum capacitor are completed in the same device, so that the oxygen contact risk caused by migration of the tantalum capacitor among different processes is avoided, the content of oxygen impurities generated by tantalum materials is reduced, and the quality and the yield of the tantalum capacitor are improved.

In combination with the first aspect, an embodiment of the present application provides a first possible implementation manner of the first aspect, further including a gas outlet pipeline and a first valve, an input end of the gas outlet pipeline is communicated with an output end of the first valve, and an input end of the first valve is respectively communicated with the condenser and the gas circulation pump.

With reference to the first aspect, an embodiment of the present application provides a second possible implementation manner of the first aspect, where the intake pipeline includes a first intake pipe, a second intake pipe, and a second valve, and both the first intake pipe and the second intake pipe are communicated with an input end of the second valve; the output end of the second valve is respectively communicated with the condenser and the gas circulating pump; the first air inlet pipe is used for being connected with an air source; and the second gas inlet pipe is used for being connected with an argon gas source.

In the implementation process, the first air inlet pipe, the second air inlet pipe and the second valve are arranged, so that different gases are controlled to enter the sintering furnace at different moments, sintering of the tantalum capacitor is completed, and the sintering effect is improved.

With reference to the first aspect, the present application provides a third possible implementation manner of the first aspect, where a capacitor tray is disposed in the sintering chamber; the capacitor tray is used for containing the tantalum capacitor.

In the implementation process, the capacitor tray is arranged, so that the tantalum capacitor can be fixed at a fixed position, and sintering of the tantalum capacitor is facilitated.

With reference to the third possible implementation manner of the first aspect, the present application provides an example of a fourth possible implementation manner of the first aspect, and a sintering heater is further disposed in the sintering chamber; the sintering heater is arranged at the edge of the capacitor tray; the sintering heater is used for heating the tantalum capacitor arranged on the capacitor tray.

With reference to the fourth possible implementation manner of the first aspect, the present application provides a fifth possible implementation manner of the first aspect, and an insulating layer is further disposed in the sintering chamber.

In the above-mentioned realization process, through setting up the heat preservation to make the gas after the heating give off the heat through the heat preservation and make the adhesive that tantalum capacitor carried volatilize, can effectively avoid heating back gas directly to contact with tantalum capacitor, and lead to tantalum capacitor to be polluted.

With reference to the first aspect, the present application provides a sixth possible implementation manner of the first aspect, further including a safety valve, where the safety valve is communicated with the sintering chamber, and is configured to discharge gas in the sintering chamber when a gas pressure in the sintering chamber exceeds a preset threshold value.

In the implementation process, the safety valve is arranged, so that when the air pressure in the sintering cavity exceeds a preset threshold value, the gas in the sintering cavity can be discharged in time, and the probability of safety accidents is reduced.

With reference to the first aspect, an embodiment of the present application provides a seventh possible implementation manner of the first aspect, and a third valve is further disposed on the condenser; the third valve is used for cleaning solid-liquid condensate in the condenser when the third valve is opened.

In the implementation process, the solid-liquid condensate in the condenser can be timely cleaned by arranging the third valve, so that the solid-liquid condensate is prevented from being carried out of the condenser.

With reference to the seventh possible implementation manner of the first aspect, an example of the present application provides an eighth possible implementation manner of the first aspect, and the condenser is further provided with a cooling liquid inlet and a cooling liquid outlet.

With reference to the first aspect, this application provides a ninth possible implementation manner of the first aspect, where the vacuum pump group includes a first vacuum pump, a second vacuum pump, and a third vacuum pump; the output end of the first vacuum pump is communicated with the input end of the second vacuum pump, and the output end of the second vacuum pump is communicated with the input end of the third vacuum pump; and the output end of the third vacuum pump is communicated with the sintering cavity.

In the implementation process, the first vacuum pump, the second vacuum pump and the third vacuum pump are connected in series, so that the vacuumizing effect in the sintering cavity is better, the sintering effect on the sintering cavity is improved, the product quality and the yield are improved, and the production efficiency is further improved.

Additional features and advantages of the disclosure will be set forth in the description which follows, or in part may be learned by the practice of the above-described techniques of the disclosure, or may be learned by practice of the disclosure.

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic structural diagram of a sintering furnace provided in an embodiment of the present application;

FIG. 2 is a schematic view of the structure at I in the sintering furnace shown in FIG. 1;

fig. 3 is a flowchart of a sintering method for sintering a tantalum capacitor in the sintering furnace shown in fig. 1.

Icon: 100-sintering furnace; 110-an air intake line; 120-gas circulation pump; 130-a gas heater; 140-a sintering chamber; 150-a condenser; 160-vacuum pump group; 170-gas outlet pipeline; 180-a first valve; 190-safety valve; 111-a first inlet pipe; 112-a second intake pipe; 113-a second valve; 141-a capacitor tray; 142-a sintered heater; 143-insulating layer; 151-third valve; 152-a coolant inlet; 153-coolant outlet; 161-a first vacuum pump; 162-a second vacuum pump; 163-third vacuum pump.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when in use, and are used only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is further noted that, unless expressly stated or limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Referring to fig. 1 to 2, an embodiment of the present application provides a sintering furnace 100, which includes an air inlet pipe 110, a gas circulation pump 120, a gas heater 130, a sintering chamber 140, a condenser 150, and a vacuum pump set 160.

Optionally, the air intake line 110 communicates with the input of the gas circulation pump 120.

It should be understood that the air inlet line 110 is connected to the gas circulation pump 120 by a pipe.

Optionally, the air intake line 110 is used to charge the gas to the gas circulation pump 120 to input the gas to the gas heater 130 through the gas circulation pump 120.

Optionally, the intake line 110 comprises a first intake pipe 111, a second intake pipe 112 and a second valve 113.

Alternatively, the first intake pipe 111 and the second intake pipe 112 are both communicated with an input end of the second valve 113.

Optionally, the first air inlet pipe 111 is used for connecting with an air source to introduce air into the sintering furnace 100; the second gas inlet pipe 112 is used for connecting with an argon gas source to introduce argon gas into the sintering furnace 100.

Optionally, the output end of the second valve 113 is respectively communicated with the condenser 150 and the gas circulation pump 120; the second valve 113 is used to control intake of the first intake pipe 111 and the second intake pipe 112. Wherein, the gas flow direction can refer to the arrow direction in fig. 1.

Alternatively, the second valve 113 may be a three-way valve to control the first intake pipe 111 and the second intake pipe 112, respectively.

Of course, in practical use, the air intake of the first air inlet pipe 111 and the second air inlet pipe 112 can be controlled by an air source connected thereto, such as an air source connected to the first air inlet pipe 111, which controls the output of air by a switch device provided in the air source.

It is to be understood that the above examples are illustrative only and not limiting.

Alternatively, the output end of the second valve 113 is communicated with a pipeline arranged between the condenser 150 and the gas circulation pump 120, that is, the condenser 150 is communicated with the gas circulation pump 120 through a pipeline, and the output end of the second valve 113 is connected to the pipeline.

In the implementation process, the first air inlet pipe 111, the second air inlet pipe 112 and the second valve 113 are arranged to control different gases to enter the sintering furnace 100 at different moments, so that the tantalum capacitor is sintered, and the sintering effect is improved.

In a possible embodiment, the sintering furnace 100 further comprises a first pressure gauge G1 and a first thermocouple R1; the first pressure gauge G1 is installed between the gas circulation pump 120 and the gas inlet pipeline 110, and the first pressure gauge G1 is used for detecting the pressure value at the input end of the gas circulation pump 120. The first thermocouple R1 is installed between the gas circulation pump 120 and the gas inlet pipeline 110, and is configured to measure a current gas temperature, subtract a preset temperature from a measured temperature to obtain a temperature difference, and heat the gas heater 130 or stop heating the gas heater 130 according to the temperature difference, for example, when the temperature difference is greater than or equal to zero, that is, the measured temperature is greater than or equal to the preset temperature, stop heating the gas heater 130, and when the temperature difference is less than zero, that is, the measured temperature is less than the preset temperature, heat the gas heater 130 to reach the preset temperature.

Optionally, the output of the gas circulation pump 120 is in communication with the input of the gas heater 130. For example, the output end of the gas circulation pump 120 and the input end of the gas heater 130 may be connected by a pipe.

Optionally, the gas circulation pump 120 is configured to, when turned on, introduce heated gas into the sintering chamber 140 and flow through the tantalum capacitor surface located in the sintering chamber 140, so as to take away the binder in the tantalum capacitor by high-temperature gas and flow into the condenser 150. For example, the gas circulation pump 120 may pressurize the gas, sequentially pass through the gas heater 130, the sintering chamber 140, and the condenser 150, and finally, the gas circulation pump 120 is again introduced to complete the gas flow circulation.

Optionally, an eighth valve F8 is further disposed between the output end of the gas circulation pump 120 and the input end of the gas heater 130, and the eighth valve F8 is used for controlling the flow rate of the gas entering the gas heater 130.

Alternatively, the eighth valve F8 may be an adjustable valve.

Optionally, the output end of the gas heater 130 is communicated with the gas inlet of the sintering chamber 140; the gas heater 130 is used for heating the gas entering the gas heater 130 and inputting the heated gas into the sintering chamber 140. For example, the gas may be heated to 350 ℃ to heat the tantalum capacitor (i.e., the tantalum embryo pieces) in the sintering chamber 140 and carry the impurities and binder in the tantalum embryo pieces out to the condenser 150. Impurities and adhesives volatilized from the tantalum embryo blocks are collected through the condenser 150, the gas enters the gas circulating pump 120 again together with the supplemented gas at the gas inlet pipeline 110 for circulation again, and after the preset time (for example, 120 minutes), the adhesive removing process is completed.

Alternatively, the adhesive may also be referred to as a binder. Here, the number of the carbon atoms is not particularly limited.

In the implementation process, the high-temperature gas is output to the sintering cavity 140 through the gas heater 130, the high-temperature gas can be quickly diffused to each part of the sintering cavity 140 after entering the sintering cavity 140, and the high-temperature gas is high in mobility and can be uniformly heated to keep the temperature in the sintering cavity 140 stable and uniform, so that the phenomenon that the adhesive is not removed due to heating through the high-temperature heater in the prior art can be avoided. For example, the high temperature heater has a small resistance below 600 ℃, heating is realized through low voltage and large current, temperature control is difficult to stabilize in a range in low temperature heating, so that the temperature rush phenomenon can occur, and the low temperature radiation efficiency is low, so that the temperature gradient between the center of the sintering cavity 140 and the outer wall is large, the adhesive can be attached to a cold zone, the adhesive is not removed, the yield of products and the quality of the products are reduced, and adverse effects on the performance of equipment can be generated.

In a possible embodiment, a fourth valve F4 is further provided between the output of the gas heater 130 and the sintering chamber 140.

Optionally, a fourth valve F4 is used to control the output of the heated gas from gas heater 130, and thus the flow of the heated gas into sintering chamber 140.

Optionally, the fourth valve F4 is an adjustable valve, i.e. a valve capable of adjusting the flow.

In a possible embodiment, the sintering furnace 100 further comprises a first passage L and a fifth valve F5, the input end of the first passage L communicating with the output end of the fifth valve F5, the input end of the fifth valve F5 communicating with the output end of the gas circulation pump 120, the output end of the first passage L communicating with the gas inlet of the sintering chamber 140.

Optionally, the fifth valve F5 is an adjustable valve.

Optionally, the gas outlet of the sintering chamber 140 is communicated with the input end of the condenser 150; the sintering cavity 140 contains a tantalum capacitor carrying a binder, and the sintering cavity 140 is used for performing vacuum high-temperature sintering on the tantalum capacitor after the binder is removed.

Optionally, a capacitor tray 141 is arranged in the sintering chamber 140; the capacitor tray 141 is used for containing the tantalum capacitor carrying the adhesive.

Optionally, a sintering heater 142 is further disposed in the sintering chamber 140; the sintering heater 142 is disposed at the edge of the capacitor tray 141; the sintering heater 142 is disposed to heat the tantalum capacitor placed on the capacitor tray 141. For example, the sintering heater 142 may heat the product to 2200 ℃.

Alternatively, the edge refers to an edge of the capacitor tray 141, such as a side edge of the capacitor tray 141. Or may be a distance from the side of the capacitor tray 141. Such as 1 cm or 2 cm, etc.

Optionally, an insulating layer 143 is further disposed in the sintering chamber 140. The heat insulating layer 143 is disposed at the periphery of the sintering heater 142, an accommodating cavity is formed between the heat insulating layer 143 and the sintering cavity 140, and the heated gas output by the gas heater 130 is input to the heat insulating layer 143 (i.e., the accommodating cavity) so as to volatilize the adhesive in the tantalum capacitor on the capacitor tray 141 by the heat emitted from the heat insulating layer 143, and the volatilized impurities and the adhesive enter the condenser 150 for condensation.

In a possible embodiment, a second pressure gauge G2 is provided on the sintering furnace 100.

Optionally, the output end of the condenser 150 is communicated with the input end of the gas circulation pump 120; the condenser 150 is configured to condense the binder carried by the gas in the condenser 150, and output the cooled gas to the gas circulation pump 120 for gas circulation, and is further configured to cool down the high-temperature gas flowing out of the sintering chamber 140 after the sintering of the sintering furnace 100 is completed.

Alternatively, the condenser 150 and the sintering chamber 140 may be connected by a pipe. A sixth valve F6 is also provided between the condenser 150 and the sintering chamber 140.

Optionally, a sixth valve F6 is used to control whether gas flows into the condenser 150.

Optionally, a third valve 151 is further disposed on the condenser 150; the third valve 151 is used to clean the solid-liquid condensate in the condenser 150 when opened. For example, to the condensed adhesive in the condenser 150.

Alternatively, the third valve 151 may be a removable flange.

In the above implementation, the third valve 151 is provided to enable the solid-liquid condensate in the condenser 150 to be cleaned in time, so as to prevent the solid-liquid condensate from being carried out of the condenser 150.

Optionally, the condenser 150 comprises a cooling fluid inlet 152 and a cooling fluid outlet 153 for regulating the cooling fluid in the condenser 150 through the cooling fluid inlet 152 and the cooling fluid outlet 153.

Alternatively, the selection of the cooling liquid can be set according to actual requirements. For example, water or a corresponding solution can be used for cooling, and a refrigerator can be connected to achieve a corresponding effect.

Optionally, the vacuum pump set 160 is in communication with the sintering chamber 140; the vacuum pump 160 is used for evacuating the sintering chamber 140.

Optionally, the vacuum pump set 160 includes a first vacuum pump 161, a second vacuum pump 162, and a third vacuum pump 163.

Optionally, the output of the first vacuum pump 161 is communicated with the input of the second vacuum pump 162, and the output of the second vacuum pump 162 is communicated with the input of the third vacuum pump 163; the output of the third vacuum pump 163 is in communication with the sintering chamber 140.

Alternatively, the first vacuum pump 161 may be any one of a diffusion pump, a roots pump, and a mechanical vacuum pump.

Alternatively, the second vacuum pump 162 may be any one of a diffusion pump, a roots pump, and a mechanical vacuum pump.

Alternatively, the third vacuum pump 163 may be any one of a diffusion pump, a roots pump, and a mechanical vacuum pump.

For example, the first vacuum pump 161 may be a diffusion pump, the second vacuum pump 162 may be a roots pump, and the third vacuum pump 163 may be a mechanical vacuum pump. Alternatively, the first vacuum pump 161 may be a diffusion pump, the second vacuum pump 162 may be a mechanical vacuum pump, and the third vacuum pump 163 may be a roots pump. Here, the number of the carbon atoms is not particularly limited.

In the implementation process, the first vacuum pump 161, the second vacuum pump 162 and the third vacuum pump 163 are connected in series, so that the effect of vacuumizing in the sintering cavity 140 is better, the sintering effect of the sintering cavity 140 is further improved, the quality and the yield of products are further improved, and the production efficiency is further improved.

Wherein, the good product rate refers to qualified product/total product amount 100%.

Optionally, a seventh valve F7 is further disposed between the output end of the third vacuum pump 163 and the sintering chamber 140. The seventh valve F7 is used to adjust the pumping pressure of the third vacuum pump 163.

Alternatively, the seventh valve F7 may be an adjustable valve.

In a possible embodiment, the sintering furnace 100 further comprises a gas outlet line 170 and a first valve 180, wherein the input end of the gas outlet line 170 is communicated with the output end of the first valve 180, and the input end of the first valve 180 is respectively communicated with the condenser 150 and the gas circulation pump 120.

Optionally, gas outlet line 170 is used to vent gases.

Optionally, a vacuum mechanical pump is connected to the output end of the gas outlet pipe 170 for pumping out the gas.

Optionally, a first valve 180 is used to control the venting of the gas.

In a possible embodiment, the sintering furnace 100 further comprises a safety valve 190, wherein the safety valve 190 is in communication with the sintering chamber 140 and is configured to vent the gas in the sintering chamber 140 when the gas pressure in the sintering chamber 140 exceeds a preset threshold.

Based on the above description, the operational principle of the sintering furnace 100 is: the capacitor tray 141 with the embryo blocks is first placed in the sintering chamber 140 and the sintering chamber 140 is sealed. The fourth valve F4, the fifth valve F5, the first valve 180, the sixth valve F6, the eighth valve F8 are opened, and the second valve 113 and the seventh valve F7 are closed. Pumping out the gas in the sintering furnace 100 to 0.5Pa through a vacuum mechanical pump connected to the gas outlet pipeline 170, closing the first valve 180, opening the second valve 113, introducing argon gas into the second gas inlet pipe 112, and opening the gas circulating pump 120 to help the gas to circulate and fully mix; closing the second valve 113 again, opening the first valve 180, closing the gas circulation pump 120, evacuating to 0.5Pa at the gas outlet pipe 170 by the mechanical pump, repeating the process for 3 times to reduce the content of impurity gases in the sintering furnace 100, filling argon gas for the last time to make the sintering furnace 100 reach a positive pressure of 0.2Mpa, referring to the first pressure gauge G1 and the second pressure gauge G2, opening the gas circulation pump 120 to circulate the gas in the sintering furnace 100, and supplementing a certain amount of argon gas (the gas supplementing process is closed loop) through the second gas inlet pipe 112 and the second valve 113 according to the reading of the first pressure gauge G1 to make the pressure at the gas inlet (i.e., the input end) of the gas circulation pump 120 reach a certain pressure. The fifth valve F5 is closed, the gas is fully heated to 350 ℃ by the gas heater 130, and the gas is filled into the heat insulation layer 143 in the sintering chamber 140 to heat the tantalum capacitor in the capacitor tray 141, and carry out impurities and adhesives in the tantalum capacitor, the volatilized impurities and adhesives are collected by the condenser 150, the gas enters the gas circulation pump 120 again together with the gas supplemented at the second gas inlet pipe 112 for circulation, and after 120 minutes, the binder removal process is completed.

Then, the sixth valve F6, the fifth valve F5, and the fourth valve F4 are closed, the seventh valve F7 is opened, and the sintering chamber 140 is evacuated to 2 × 10 by the first vacuum pump 161, the second vacuum pump 162, and the third vacuum pump 163^-3Pa, the product is sintered by heating to 1850 ℃ for 30 minutes under vacuum and high temperature by a sintering heater 142. After sintering, the temperature is reduced to below 400 ℃, the seventh valve F7 is closed, the sixth valve F6 and the fifth valve F5 are opened, argon is filled through the second air inlet pipe 112, the gas circulating pump 120 is started after the pressure reaches 0.2Mpa, the argon is circulated in the sintering furnace 100, the temperature in the sintering cavity 140 is brought out, and the temperature is cooled again through the condenser 150 for rapid cooling. And cooling the product to below 40 ℃, pumping out the gas again, introducing air to reach 5000Pa through the first air inlet pipe 111, pumping out the gas again, introducing air to reach 5000Pa again, circulating for 3 times in this way, taking out the product after the product is passivated, and further completing sintering of the product.

In order to more intuitively show the beneficial effects of the sintering furnace 100 in the embodiment of the present application, the sintering experiment results of the sintering furnace 100 in the embodiment of the present application are compared with the existing method, as shown in tables one to six:

watch 1

Watch two

Watch III

Watch four

Watch five

Watch six

It can be seen from tables one to six that the capacity C and the loss tan δ (%) of the product are not substantially changed, the ESR of the product tends to be small, the maximum LC value of the product is small, the product has no large offset, the dispersion range is small, and the performance of the product is relatively stable compared with the prior art.

It should be noted that the sintering furnace provided in the embodiments of the present application may not only be used for sintering tantalum, but also be used for sintering a material that must be removed from a fixture and then moved to the sintering furnace for sintering.

Referring to fig. 3, the present embodiment provides a flow chart of a sintering method for tantalum capacitors, and it should be understood that the method shown in fig. 3 can be implemented by using the sintering furnace shown in fig. 1, and the method includes the following steps:

and S101, placing the pressed tantalum capacitor containing the adhesive in a sintering cavity.

Alternatively, the pressed tantalum capacitor containing the adhesive can be manually placed in the sintering cavity, or the pressed tantalum capacitor containing the adhesive can be placed in the sintering cavity by a robot or a robot hand. Here, the number of the carbon atoms is not particularly limited.

And S102, vacuumizing the sintering cavity and introducing gas.

Optionally, the gas is argon.

Of course, other inert gases, such as helium (He), neon (Ne), krypton (Kr), and xenon (Xe), may be used in practice. Other mixed gases that do not affect the sintering in the sintering furnace may be used. Here, the number of the carbon atoms is not particularly limited.

Step S103, the gas heater is started, and the gas entering the gas heater is heated to a first preset temperature range.

Optionally, the first preset temperature range is 200-550 ℃.

Alternatively, the setting of the first preset temperature range may be set according to an increasing temperature of the adhesive.

And step S104, starting the gas circulating pump, introducing the heated gas into the sintering cavity and flowing through the surface of the tantalum capacitor so as to take away the adhesive in the tantalum capacitor through high-temperature gas and then flow into the condenser.

Alternatively, after entering the condenser, the binder condenses therein under the cooling action of the condenser. And after 30-150 minutes of circulation, closing the gas circulating pump and the gas heater.

And step S105, vacuumizing the sintering cavity again.

Optionally, please refer to the above description of the working principle of the sintering furnace for the specific implementation process of step S105, and the description thereof is omitted here.

And S106, heating the tantalum capacitor in the re-vacuumized sintering cavity to finish sintering the tantalum capacitor.

Optionally, the tantalum capacitor is heated to a sintering temperature of 1200-2200 ℃ and kept for 10-60 minutes.

Optionally, please refer to the above description of the working principle of the sintering furnace for the specific implementation process of step S106, and the description thereof is omitted here.

In a possible embodiment, after step S106, the method further comprises: cooling the sintered tantalum capacitor; and taking out the cooled tantalum capacitor.

In the implementation process, the pressed tantalum capacitor containing the adhesive is placed in a sintering cavity; vacuumizing the sintering cavity and introducing gas; starting the gas heater, and heating the gas entering the gas heater to a first preset temperature range; starting the gas circulating pump, introducing the heated gas into the sintering cavity and flowing the gas through the surface of the tantalum capacitor, so that the high-temperature gas takes away the adhesive in the tantalum capacitor and then flows into the condenser; vacuumizing the sintering cavity again; and heating the tantalum capacitor in the re-vacuumized sintering cavity to finish sintering the tantalum capacitor. The technological process of removing the adhesive and the sintering technological process of the tantalum capacitor are completed in the same equipment, the oxygen contact risk caused by migration of the tantalum capacitor among different technologies is avoided, the quality and the yield of the tantalum capacitor are improved, two technological processes do not need to be carried out independently, the migration time is saved, and the production efficiency is further improved.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A sintering furnace, comprising: the device comprises an air inlet pipeline, a gas circulating pump, a gas heater, a sintering cavity, a condenser and a vacuum pump set;

the air inlet pipeline is communicated with the input end of the gas circulating pump; the gas inlet pipeline is used for charging gas to the gas circulating pump so as to input the gas into the gas heater through the gas circulating pump;

the output end of the gas circulating pump is communicated with the input end of the gas heater; the gas circulating pump is used for introducing heated gas into the sintering cavity and flowing the heated gas through the surface of the tantalum capacitor in the sintering cavity when the gas circulating pump is started, so that the adhesive in the tantalum capacitor is taken away by high-temperature gas and then flows into the condenser;

the output end of the gas heater is communicated with the gas inlet of the sintering cavity; the gas heater is used for heating the gas entering the sintering chamber and inputting the heated gas into the sintering chamber;

the air outlet of the sintering cavity is communicated with the input end of the condenser; the sintering cavity is used for carrying out vacuum high-temperature sintering on the tantalum capacitor after the adhesive is removed;

the output end of the condenser is communicated with the input end of the gas circulating pump; the condenser is used for condensing the adhesive carried by the gas in the condenser, outputting the cooled gas to the gas circulating pump for gas circulation and cooling the high-temperature gas flowing out of the sintering cavity after the sintering of the sintering furnace is finished;

the vacuum pump set is communicated with the sintering cavity; the vacuum pump set is used for vacuumizing the sintering cavity.

2. The sintering furnace according to claim 1, further comprising a gas outlet pipeline and a first valve, wherein an input end of the gas outlet pipeline is communicated with an output end of the first valve, and an input end of the first valve is respectively communicated with the condenser and the gas circulating pump.

3. Sintering furnace according to claim 1, characterized in that the air inlet line comprises a first air inlet pipe, a second air inlet pipe and a second valve, both of which are in communication with an input end of the second valve; the output end of the second valve is respectively communicated with the condenser and the gas circulating pump;

the first air inlet pipe is used for being connected with an air source;

and the second gas inlet pipe is used for being connected with an argon gas source.

4. Sintering furnace according to claim 1, characterized in that a capacitor tray is arranged in the sintering chamber;

the capacitor tray is used for containing the tantalum capacitor.

5. The sintering furnace according to claim 4, characterized in that a sintering heater is arranged in the sintering cavity;

the sintering heater is arranged at the edge of the capacitor tray;

the sintering heater is used for heating the tantalum capacitor arranged on the capacitor tray.

6. The sintering furnace according to claim 5, characterized in that an insulating layer is arranged in the sintering cavity.

7. The sintering furnace of claim 1, further comprising a safety valve in communication with the sintering chamber for venting gas from the sintering chamber when the gas pressure in the sintering chamber exceeds a predetermined threshold.

8. Sintering furnace according to claim 1, characterized in that the condenser is also provided with a third valve;

the third valve is used for cleaning solid-liquid condensate in the condenser when the third valve is opened.

9. The sintering furnace according to claim 8, wherein the condenser is further provided with a cooling liquid inlet and a cooling liquid outlet.

10. Sintering furnace according to claim 1, characterized in that the vacuum pump group comprises a first vacuum pump, a second vacuum pump and a third vacuum pump;

the output end of the first vacuum pump is communicated with the input end of the second vacuum pump, and the output end of the second vacuum pump is communicated with the input end of the third vacuum pump; and the output end of the third vacuum pump is communicated with the sintering cavity.

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