Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887594
A. Tulbure, E. Ceuca, D. Turschner
Most manufacturers of electronics components focus on dedicated market, their core of competence, on macro- or microelectronics. Therefore, the specific applications are the sometimes the responsibility of the users. Starting from this idea, the authors describe the relevant electrical phenomena occurring in the public transportation systems (PTS). These represent the foundation of a technical specification, taken as a reference for tester development. In this context, the proposed module combines power circuits (semiconductors and protections) with control circuits (sensors and controller) in one test bench for electronic switches of urban traction systems, at a reasonable price-performance ratio [1],[2]. One important characteristic of this device is the high scalability. It is suited for many switching frequencies and gate amplitudes, control algorithms and drive powers.
{"title":"Arduino based power semiconductors tester for urban traction systems","authors":"A. Tulbure, E. Ceuca, D. Turschner","doi":"10.1109/ISSE.2014.6887594","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887594","url":null,"abstract":"Most manufacturers of electronics components focus on dedicated market, their core of competence, on macro- or microelectronics. Therefore, the specific applications are the sometimes the responsibility of the users. Starting from this idea, the authors describe the relevant electrical phenomena occurring in the public transportation systems (PTS). These represent the foundation of a technical specification, taken as a reference for tester development. In this context, the proposed module combines power circuits (semiconductors and protections) with control circuits (sensors and controller) in one test bench for electronic switches of urban traction systems, at a reasonable price-performance ratio [1],[2]. One important characteristic of this device is the high scalability. It is suited for many switching frequencies and gate amplitudes, control algorithms and drive powers.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"518 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123118917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887647
A. Kłossowicz, P. Winiarski, M. Zawierta, W. Stęplewski, A. Dziedzic
This paper presents studies of long-term stability of capacitors embedded in printed circuit boards. Planar capacitors fabricated from FaradFlex dielectric foil with copper plates laminated to FR-4 substrate served as test structures. The dielectric was BaTiO3 ceramic/polymer composition with various fillers and consequently various dielectric constants. Moreover test samples differed in composition thickness and surface size. The investigated capacitors were covered with LDP 2×106 (Laser Drillable Prepreg) protective layers to achieve embedded structures. The behaviour of capacitance as well as dissipation factor was investigated for two values of frequency (1 and 10 kHz) in order to determine their long-term stability. The in-situ accelerated ageing process (capacitance and dissipation factor of test samples performed directly at the ageing conditions) was carried out to perform long-term behaviour analysis. Temperature characteristics both before and after aging process were performed for determination of influence of environmental exposure. Additionally insulation resistance under voltage and temperature stress was monitored and analyzed.
{"title":"Analysis of long-term stability of capacitors embedded in printed circuit boards","authors":"A. Kłossowicz, P. Winiarski, M. Zawierta, W. Stęplewski, A. Dziedzic","doi":"10.1109/ISSE.2014.6887647","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887647","url":null,"abstract":"This paper presents studies of long-term stability of capacitors embedded in printed circuit boards. Planar capacitors fabricated from FaradFlex dielectric foil with copper plates laminated to FR-4 substrate served as test structures. The dielectric was BaTiO3 ceramic/polymer composition with various fillers and consequently various dielectric constants. Moreover test samples differed in composition thickness and surface size. The investigated capacitors were covered with LDP 2×106 (Laser Drillable Prepreg) protective layers to achieve embedded structures. The behaviour of capacitance as well as dissipation factor was investigated for two values of frequency (1 and 10 kHz) in order to determine their long-term stability. The in-situ accelerated ageing process (capacitance and dissipation factor of test samples performed directly at the ageing conditions) was carried out to perform long-term behaviour analysis. Temperature characteristics both before and after aging process were performed for determination of influence of environmental exposure. Additionally insulation resistance under voltage and temperature stress was monitored and analyzed.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129210995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887563
P. Fulmek, G. Langer, F. Wenzl, W. Nemitz, S. Schweitzer, H. Hoschopf, J. Nicolics
The light quality and long-term stability of phosphor converted light-emitting diodes (LEDs) for luminaires depend on the temperature distribution inside the LED chip and the color conversion element. Therefore, a reliable and accurate method to establish the LED's junction temperature is required to further improve and optimize high quality LED luminaires. In this paper we describe the development and application of an innovative junction temperature measurement method which is based on a precise and universally applicable calibration procedure, allowing to use the calibrated LED itself as a temperature sensor under the respective operation condition of interest. This method is based on an extremely fast pulse measurement procedure allowing to record pairs of forward current and voltage drop values periodically every microsecond starting from the first microsecond of a pulse. From these experiments we reap two kinds of result: (1) Independent of the pulse shape in our experiments we observe a constant relation of current-to-voltage drop which we interpret as a constant junction conductivity. Depending on the type of LED (but independent of the packaging technology) we obtain a constant junction conductivity throughout several ten microseconds which we understand as a proof that the junction temperature did not change during this very first pulse phase. (2) The junction conductivity obtained in this moment is a measure for the junction temperature so that a calibration can be made by comparison with an independent steady-state temperature measurement made at zero-current condition. The method has been successfully applied to thermally characterize high-power LED modules as a 3 × 3 LED arrays with color conversion glob tops built-up on an insulated metal substrate (IMS).
{"title":"Direct junction temperature measurement in high-power LEDs","authors":"P. Fulmek, G. Langer, F. Wenzl, W. Nemitz, S. Schweitzer, H. Hoschopf, J. Nicolics","doi":"10.1109/ISSE.2014.6887563","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887563","url":null,"abstract":"The light quality and long-term stability of phosphor converted light-emitting diodes (LEDs) for luminaires depend on the temperature distribution inside the LED chip and the color conversion element. Therefore, a reliable and accurate method to establish the LED's junction temperature is required to further improve and optimize high quality LED luminaires. In this paper we describe the development and application of an innovative junction temperature measurement method which is based on a precise and universally applicable calibration procedure, allowing to use the calibrated LED itself as a temperature sensor under the respective operation condition of interest. This method is based on an extremely fast pulse measurement procedure allowing to record pairs of forward current and voltage drop values periodically every microsecond starting from the first microsecond of a pulse. From these experiments we reap two kinds of result: (1) Independent of the pulse shape in our experiments we observe a constant relation of current-to-voltage drop which we interpret as a constant junction conductivity. Depending on the type of LED (but independent of the packaging technology) we obtain a constant junction conductivity throughout several ten microseconds which we understand as a proof that the junction temperature did not change during this very first pulse phase. (2) The junction conductivity obtained in this moment is a measure for the junction temperature so that a calibration can be made by comparison with an independent steady-state temperature measurement made at zero-current condition. The method has been successfully applied to thermally characterize high-power LED modules as a 3 × 3 LED arrays with color conversion glob tops built-up on an insulated metal substrate (IMS).","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133418744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887645
J. Morris, Lisa H. Weasel, P. Moeck, J. Snow
Interdisciplinary faculty from Physics, Biology and Electrical and Computer Engineering, (ECE) have created a sequence of three stand-alone 300-level general education lecture courses in nanotechnology with one supporting laboratory course, with the support of National Science Foundation funding through the nanotechnology Undergraduate Education initiative. These three lecture courses can be taken by non-majors as science courses for General Education credit and are tailored to support interaction between STEM (science, technology, engineering and mathematics) and non-STEM students, who will take them together. The ECE and Biology courses have each run once and course feedback and analyses are summarized here.
{"title":"Nanotechnology courses for general education","authors":"J. Morris, Lisa H. Weasel, P. Moeck, J. Snow","doi":"10.1109/ISSE.2014.6887645","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887645","url":null,"abstract":"Interdisciplinary faculty from Physics, Biology and Electrical and Computer Engineering, (ECE) have created a sequence of three stand-alone 300-level general education lecture courses in nanotechnology with one supporting laboratory course, with the support of National Science Foundation funding through the nanotechnology Undergraduate Education initiative. These three lecture courses can be taken by non-majors as science courses for General Education credit and are tailored to support interaction between STEM (science, technology, engineering and mathematics) and non-STEM students, who will take them together. The ECE and Biology courses have each run once and course feedback and analyses are summarized here.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133662788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887641
N. Codreanu, G. Vărzaru, C. Ionescu
The paper presents the design and experiments of a multi-sensor device for use in agriculture crop irrigation. The soil and environment parameters are determined by specific sensors under the supervision of a microcontroller and sent through wireless communication to a central unit. The novelty is the assembly of all the sensors on a single structure, together with the wireless communication circuitry to permit the power management of the electronics in order to allow an autonomous supplying from a solar cell in parallel with a Li-Ion accumulator. The design of the power source was done to assure a 3.3V voltage. The research work was firstly focused on soil parameters: moisture and temperature. The main experiments were performed in order to calibrate the method used for sensing the soil moisture.
{"title":"Solar powered wireless multi-sensor device for an irrigation system","authors":"N. Codreanu, G. Vărzaru, C. Ionescu","doi":"10.1109/ISSE.2014.6887641","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887641","url":null,"abstract":"The paper presents the design and experiments of a multi-sensor device for use in agriculture crop irrigation. The soil and environment parameters are determined by specific sensors under the supervision of a microcontroller and sent through wireless communication to a central unit. The novelty is the assembly of all the sensors on a single structure, together with the wireless communication circuitry to permit the power management of the electronics in order to allow an autonomous supplying from a solar cell in parallel with a Li-Ion accumulator. The design of the power source was done to assure a 3.3V voltage. The research work was firstly focused on soil parameters: moisture and temperature. The main experiments were performed in order to calibrate the method used for sensing the soil moisture.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130295376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887564
P. Matkowski
Consumer electronics such as portable devices (laptops, smartphones) become smaller, thinner and more powerful. In such devices a passive cooling begins to play a dominant role in heat dissipation process. In passive cooling systems thermal resistance of thermal path between semiconductor junction and radiator should be progressively reduced. It can be done by application of efficient (high thermal conductivity) thermal interface materials. The main aim of the study was to provide and to characterize developed thermal greases based on mixture of nano and micro fillers, which could compete or replace the current commercial ones.
{"title":"Comparative thermal analysis of commercial and novel hybrid thermal greases","authors":"P. Matkowski","doi":"10.1109/ISSE.2014.6887564","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887564","url":null,"abstract":"Consumer electronics such as portable devices (laptops, smartphones) become smaller, thinner and more powerful. In such devices a passive cooling begins to play a dominant role in heat dissipation process. In passive cooling systems thermal resistance of thermal path between semiconductor junction and radiator should be progressively reduced. It can be done by application of efficient (high thermal conductivity) thermal interface materials. The main aim of the study was to provide and to characterize developed thermal greases based on mixture of nano and micro fillers, which could compete or replace the current commercial ones.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130321925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887569
P. Svasta, A. Marghescu, Traian Neacşa
In cryptography, for message/data integrity assurances, that are vital for a security product, are used Hash functions. The Hash algorithm is based on a one-way-function that maps an arbitrary-length data to a fixed-length output. This paper will present the usage of the newest hash algorithm SHA-3 - Keccak into an electronic module based on FPGA. This will work, along with an ARM Cortex-A9 microprocessor, as a cryptographic coprocessor. The implemented hardware solution significantly increased the computational speed of the signal data processing.
{"title":"Cryptographic coprocessor for data integrity algorithms","authors":"P. Svasta, A. Marghescu, Traian Neacşa","doi":"10.1109/ISSE.2014.6887569","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887569","url":null,"abstract":"In cryptography, for message/data integrity assurances, that are vital for a security product, are used Hash functions. The Hash algorithm is based on a one-way-function that maps an arbitrary-length data to a fixed-length output. This paper will present the usage of the newest hash algorithm SHA-3 - Keccak into an electronic module based on FPGA. This will work, along with an ARM Cortex-A9 microprocessor, as a cryptographic coprocessor. The implemented hardware solution significantly increased the computational speed of the signal data processing.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132976005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887602
K. Urbanski, T. Falat, P. Matkowski, M. Szczerba, J. Felba, A. Moscicki
In this paper preliminary investigations of electrical properties of new Thermal Interface Materials (TIMs') are presented and discussed. Investigated TIMs are based on mixture of silver flakes and silver nano-particles (nano-Ag) with high content of silver (more than 90% weight). After curing and sintering of such materials, as a result, a bulk, homogenous silver layer with good electrical and mechanical properties is formed. This makes those materials suitable for high-power electronics since both thermal and electrical conductivity of the bulk silver is very high (429 W·m-1·K-1). What makes investigated materials very valuable is a relatively low temperature of sintering process (typ. 120-150°C).
{"title":"Investigation of electrical properties of contacts made of materials based on sintered nano-Ag particles","authors":"K. Urbanski, T. Falat, P. Matkowski, M. Szczerba, J. Felba, A. Moscicki","doi":"10.1109/ISSE.2014.6887602","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887602","url":null,"abstract":"In this paper preliminary investigations of electrical properties of new Thermal Interface Materials (TIMs') are presented and discussed. Investigated TIMs are based on mixture of silver flakes and silver nano-particles (nano-Ag) with high content of silver (more than 90% weight). After curing and sintering of such materials, as a result, a bulk, homogenous silver layer with good electrical and mechanical properties is formed. This makes those materials suitable for high-power electronics since both thermal and electrical conductivity of the bulk silver is very high (429 W·m-1·K-1). What makes investigated materials very valuable is a relatively low temperature of sintering process (typ. 120-150°C).","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114172120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887571
M. Klíma, J. Somer, L. Blahová, M. Procházka, I. Szendiuch
This article deals with usage of low-temperature co-fired ceramic as a material for hermetic package of bare-dies. Two types of substrates are measured - Heraeus HeraLock2000 and DuPont GreenTape 951PT. For more accurate results, different arrays of vias are designed to imitate conductive joints in a package. An air-tightness of samples is determined based on Oxygen Transmission Rate measurement. Dependence of the air-tightness on a material thickness and on a count of vias was investigated. Design and fabrication of the samples and measurement description is also included. Results of this experiment compare mentioned types of ceramics and create a base of knowledge for design of an air-tight package.
{"title":"Usage of low-temperature co-fired ceramic in hermetic packaging","authors":"M. Klíma, J. Somer, L. Blahová, M. Procházka, I. Szendiuch","doi":"10.1109/ISSE.2014.6887571","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887571","url":null,"abstract":"This article deals with usage of low-temperature co-fired ceramic as a material for hermetic package of bare-dies. Two types of substrates are measured - Heraeus HeraLock2000 and DuPont GreenTape 951PT. For more accurate results, different arrays of vias are designed to imitate conductive joints in a package. An air-tightness of samples is determined based on Oxygen Transmission Rate measurement. Dependence of the air-tightness on a material thickness and on a count of vias was investigated. Design and fabrication of the samples and measurement description is also included. Results of this experiment compare mentioned types of ceramics and create a base of knowledge for design of an air-tight package.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127530576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-07DOI: 10.1109/ISSE.2014.6887560
A. Staat, T. Hohlfeld, T. Standau, I. Weimann, R. Bauer, K. Harre
Using standard conductive paste screen printing on standard substrates and substrates based on renewable resources was done. While the parameters of the screen printing were kept unchanged, the curing temperature of the screen printed structures was varied. The resulting contact pattern were examined in regard to their resistivity and the mechanical resistance. Furthermore, the resolution of the pattern in dependency of substrate and curing temperature was studied. Additionally the burning behavior of the substrate was comparatively examined.
{"title":"Substrates based on renewable resources for printed circuit boards","authors":"A. Staat, T. Hohlfeld, T. Standau, I. Weimann, R. Bauer, K. Harre","doi":"10.1109/ISSE.2014.6887560","DOIUrl":"https://doi.org/10.1109/ISSE.2014.6887560","url":null,"abstract":"Using standard conductive paste screen printing on standard substrates and substrates based on renewable resources was done. While the parameters of the screen printing were kept unchanged, the curing temperature of the screen printed structures was varied. The resulting contact pattern were examined in regard to their resistivity and the mechanical resistance. Furthermore, the resolution of the pattern in dependency of substrate and curing temperature was studied. Additionally the burning behavior of the substrate was comparatively examined.","PeriodicalId":375711,"journal":{"name":"Proceedings of the 2014 37th International Spring Seminar on Electronics Technology","volume":"457 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125806689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：