Main Question: Why does the dashboard of my new energy vehicle flicker while charging? Is it caused by the unstable output capacitor capacity of the DC-DC converter?
Derivative Question:
Question Type: Reliability/Failure
Q: During the charging process of a new energy vehicle, the dashboard or central control screen flickers or restarts momentarily. What could be the reason?
A: This phenomenon is likely because during vehicle charging, the power battery pack briefly disconnects power for safety checks. At this time, the low-voltage electrical equipment of the entire vehicle (such as the dashboard and infotainment system) relies entirely on the DC-DC converter. If the capacitance at the DC-DC output is insufficient or unstable, it cannot replenish power in time when the load suddenly increases, causing a momentary drop in output voltage and resulting in screen flickering. YMIN VHT/VHU series automotive-grade capacitors have their capacitance strictly controlled within the industry-high standard range of 0~+20%, ensuring that each individual capacitor can provide sufficient and stable power buffering, fundamentally eliminating voltage drop problems caused by insufficient capacitance or large dispersion.
Question Type: Design Support
Q: How to select capacitors for the output filter circuit of the DC-DC converter in a new energy vehicle to ensure power supply stability?
A: The key to choosing a capacitor lies in its capacitance stability and ripple current tolerance. First, the capacitor’s rated capacitance must be large enough to maintain voltage stability under varying loads. More importantly, the actual capacitance value should deviate little from the nominal value. YMIN automotive-grade capacitors, through strict process control, precisely control capacitance deviation within 0~+20% (better than the industry-common ±20%). This means that power output stability is more easily guaranteed during the design and testing phases, avoiding system risks caused by excessively low capacitance limits.
Question Type: Supply Chain Issue
Q: Poor capacitance consistency between different batches of capacitors leads to fluctuations in yield during DC-DC board factory testing. How can this be resolved?
A: This is a typical supply chain quality control issue. YMIN capacitors ensure extremely high consistency in key parameters, especially capacitance, of its products by introducing 100% CCD detection and rigorous aging tests throughout the entire manufacturing process (such as riveting, winding, impregnation, and assembly). By stabilizing capacitance tolerance within a narrow range of 0% to +20%, consistent performance of your DCDC boards across different batches is ensured, significantly improving factory yield and product reliability.
Question Type: Technical Principle
Q: Why is capacitor capacitance accuracy so important in DCDC circuit design? Isn’t there a feedback loop for adjustment?
A: While the feedback loop can indeed be adjusted, its response speed is limited. When faced with microsecond- or millisecond-level instantaneous load changes, the feedback loop cannot respond in time. In this situation, the responsibility of maintaining voltage stability falls entirely on the “instantaneous discharge” capability of the output capacitor. If the actual capacitance of the capacitor is lower than the design value (e.g., a nominal 330μF capacitor with an actual value of only 270μF), its energy storage will be insufficient to cope with instantaneous high current demands, leading to voltage drops and system instability. YMIN Capacitors guarantees a minimum capacitance no less than the nominal value, providing a solid hardware foundation for your high-speed dynamic response.
Question Type: Compatibility/Replacement
Q: Are there any automotive-grade solid-state or hybrid capacitors recommended, requiring large capacitance and good consistency, for DC-DC modules in high-end new energy vehicles?
A: We recommend YMIN’s VHT and VHU series polymer hybrid solid-state capacitors. This series is specifically designed for automotive electronics applications, offering not only high capacitance density to meet large capacity requirements, but also, more importantly, strictly controlled capacitance tolerance within 0~+20%, ensuring excellent individual consistency. For example, models VHT_35V_330μF and VHU_35V_270μF are widely used in high-voltage platform DC-DC converters in new energy vehicles, effectively ensuring the purity and stability of power output and meeting the stringent reliability requirements of high-end models.
Main Question: Our DC-DC board experiences excessive leakage current after reflow soldering, resulting in substandard static power consumption. Are there any capacitors that maintain low leakage current after high-temperature soldering?
Derivative Questions:
Question Type: Reliability/Failure
Q: After SMT surface mount reflow soldering, the standby power consumption of the DC-DC power board exceeds the standard. Investigation revealed that this is caused by increased capacitor leakage current. How can this be avoided?
A: This is a common challenge in the industry, stemming from the micro-damage caused to the internal dielectric of the capacitors by the high-temperature thermal stress of reflow soldering. YMIN Capacitors solves this problem through two core measures: First, CCDs are installed in key processes such as riveting and winding during production for 100% inspection to eliminate initial defects; second, multiple rigorous aging tests are conducted before shipment, 100% eliminating products whose leakage current parameters are prone to deterioration after thermal shock. This ensures that the capacitors delivered to your factory, after reflow soldering, still have leakage current far below the standard requirements, guaranteeing that the overall standby power consumption meets the standards.
Question Type: Testing and Verification
Q: Can you provide data to prove that the leakage current of your capacitors remains stable after reflow soldering?
A: Yes. Taking the test data of YMIN VHU_35V_270μF_10*10.5 model as an example, the test shows that after reflow soldering, the average leakage current increase of 100 samples is less than 1μA. This data fully demonstrates the leakage current stability of YMIN capacitors after soldering thermal stress, meeting the most stringent static power consumption requirements.
Question Type: Design Support
Q: To reduce the standby power consumption of DC-DC modules, what parameters should be considered when selecting capacitors?
A: Besides capacitance and ESR, leakage current is a key parameter, especially in applications requiring low-power standby standards. You need to pay attention not only to the initial leakage current value on the capacitor datasheet, but more importantly, to its leakage current performance after experiencing the high temperatures of reflow soldering. YMIN capacitors’ factory inspection standards include strict control over this aspect, ensuring that the product maintains extremely low leakage current after soldering, thereby directly helping you reduce the overall static power consumption of the device.
Question Type: Reliability/Failure
Q: Our automotive electronics products have extremely high failure rate requirements (near-zero defects). What quality control measures do your capacitors employ to support this?
A: YMIN Capacitors implements a “zero-defect” oriented quality control system. Specifically, to prevent excessive leakage current, we have installed CCD automatic optical inspection equipment in all critical processes during production, such as riveting, winding, impregnation, and assembly, to conduct 100% inspection and prevent any potentially damaged semi-finished products from entering the next process. Finally, through multiple screening processes including power-on aging and parameter testing, we ensure that any products that might experience parameter degradation after reflow soldering at the customer’s site are eliminated in advance. This comprehensive control approach provides a strong guarantee for your high reliability.
Question Type: Performance Comparison
Q: Compared to ordinary surface-mount aluminum electrolytic capacitors, what are the advantages of YMIN’s polymer hybrid capacitors in resisting reflow soldering thermal stress?
A: Ordinary surface-mount aluminum electrolytic capacitors use liquid electrolyte, which is more prone to bulging at high temperatures. Hybrid capacitors, on the other hand, use a combination of polymer solids and liquid electrolyte, which reduces the risk of bulging.
Post time: Nov-21-2025