Main Problem: Dashboard Flickering During New Energy Vehicle Charging? The Core Cause May Be Related to the DC-DC Converter Capacitor!

Problem Type: Reliability/Failure

Q: During the charging process of new energy vehicles, the dashboard or central control screen frequently flickers or even restarts. What is the underlying reason?

A: The core reason for this phenomenon is directly related to the power supply logic during charging—when a new energy vehicle is charging, the power battery pack will be briefly disconnected for a safety "check-up." During this time, all low-voltage electrical devices, such as the dashboard and vehicle infotainment system, rely solely on the DC-DC converter (the core component of the vehicle's power conversion) for power. If the capacitor at the DC-DC output end has insufficient capacity or poor stability, it cannot "replenish energy" in time when the load suddenly increases, causing the output voltage to drop instantly, thus triggering screen flickering.

Yongming's VHT/VHU series automotive-grade capacitors strictly control capacitance tolerance within the industry-leading range of 0~+20%. Each capacitor provides ample and stable power buffering, fundamentally solving the voltage drop problem caused by insufficient capacitance or large parameter differences, thus ensuring the stable operation of automotive electronic equipment.

Question Type: Design Support

Q: How can I ensure the stability of the power supply by selecting capacitors for the output filter circuit of a DC-DC converter in a new energy vehicle?

A: The key to capacitor selection lies in two core indicators: capacitance stability and ripple current withstand capability. First, the rated capacitance must be sufficient to stabilize the voltage under load fluctuations; more importantly, the deviation between the actual capacitance and the nominal value should be as small as possible to avoid a situation where the nominal value meets the standard, but the actual performance does not.

ymin automotive-grade capacitors employ rigorous end-to-end process control to precisely lock capacitance deviation within 0~+20% (superior to the industry-common ±20% standard). This means engineers can more accurately predict power output stability during the design and testing phases, mitigating system risks caused by capacitor capacitance falling below the lower limit from the design stage.

Problem Type: Supply Chain Issue

Q: Inconsistent capacitor capacitance across different batches leads to fluctuations in the yield rate of DC-DC board factory testing. How can this industry pain point be solved?

A: This is a common supply chain quality control challenge faced by the new energy vehicle electronics industry. The core issue lies in insufficient consistency of capacitor parameters. ymin capacitors provides a targeted solution: introducing 100% automated CCD detection throughout the entire production process, including riveting, winding, impregnation, and assembly, coupled with multiple rounds of rigorous aging tests, to ensure extremely high consistency of key parameters (especially capacitance) in the finished products.

By stabilizing capacitance tolerance within a narrow range of 0% to +20%, ymin Capacitors ensures consistent performance across different batches of DCDC boards, significantly improving factory yield and reducing production costs caused by capacitor parameter fluctuations.

Question Type: Technical Principle

Q: Why is capacitor capacitance accuracy so critical in DCDC circuit design? Can't the feedback loop adjust and compensate?

A: While the feedback loop has adjustment capabilities, it suffers from a slow response time. When faced with microsecond- or millisecond-level instantaneous load changes, the feedback loop simply cannot react in time. In this situation, the responsibility of maintaining voltage stability falls entirely on the output capacitor's instantaneous discharge capability.

If the actual capacitance is lower than the design value (e.g., a nominal 330μF capacitor with an actual value of only 270μF), the energy storage will be insufficient to handle instantaneous high current demands, ultimately leading to voltage drops and system instability. ymin Capacitors ensures that the minimum capacitance is not lower than the nominal value through stringent quality control, providing solid hardware support for the high-speed dynamic response of DCDC circuits and guaranteeing power supply stability. Question Type: Compatibility/Replacement

Q: High-end new energy vehicle DC-DC modules require automotive-grade solid-state or hybrid capacitors with large capacity and high consistency. What are some high-quality options?

A: Yongming's VHT and VHU series polymer hybrid solid-state capacitors are ideal choices. Designed specifically for high-voltage automotive electronics applications, this series not only boasts high capacitance density, easily meeting large capacity requirements, but also stands out for its exceptional consistency—capacity tolerance is strictly controlled within 0~+20%, with minimal individual performance differences.

Currently, models such as VHT_35V_330μF and VHU_35V_270μF are widely used in DC-DC converters on high-voltage platforms in new energy vehicles. Their stable performance effectively ensures the purity and stability of the power output, perfectly matching the stringent reliability requirements of high-end vehicles for electronic components.

Main Issue: Excessive leakage current and unacceptable static power consumption after reflow soldering of the DC-DC board? Low-leakage automotive-grade capacitors are here!

Problem Type: Reliability/Failure

Q: After SMT reflow soldering, the standby power consumption of the DC-DC power board exceeds the standard. Investigation revealed increased capacitor leakage current. How can this be prevented?

A: This is a typical pain point in the automotive electronics manufacturing industry—the high-temperature thermal shock during reflow soldering can easily cause minor damage to the internal dielectric of capacitors, leading to increased leakage current and ultimately affecting the overall standby power consumption. Yongming Capacitors solves this problem through two core technological approaches: First, 100% full inspection is conducted using CCD automatic detection equipment in key processes such as riveting and winding during production, eliminating initial defects at the source; second, multiple rigorous aging tests are conducted before shipment, 100% eliminating products whose leakage current parameters are easily degraded after thermal shock.

These measures ensure that every capacitor delivered to the factory, even after undergoing the high temperatures of reflow soldering, has a leakage current far below industry standards, providing a solid defense for meeting the overall standby power consumption standards.

Question Type: Test and Verification

Q: Do you have actual test data to prove that your capacitors maintain stable leakage current after reflow soldering?

A: The answer is yes, actual test data is the strongest proof. Taking the Yongming VHU_35V_270μF_10*10.5 capacitor as an example, our laboratory conducted reflow soldering simulation tests on 100 samples. The results showed that after high-temperature soldering, the average leakage current increase was less than 1μA.

This solid data fully demonstrates the leakage current stability of Yongming capacitors after being subjected to soldering thermal stress, easily meeting even the most stringent static power consumption requirements.


Question Type: Design Support

Q: To reduce the standby power consumption of a DC-DC module, what parameters should be focused on when selecting capacitors?

A: Besides the well-known capacitance and ESR (Equivalent Series Resistance), leakage current is an easily overlooked but crucial parameter—especially for automotive electronic applications that need to meet low-power standby standards.

When selecting capacitors, it's crucial to consider not only the initial leakage current value on the capacitor's datasheet but also its leakage current performance after undergoing the high temperatures of reflow soldering. ymin Capacitors incorporates post-soldering leakage current stability into its core factory inspection standards. Through stringent control, they ensure products maintain extremely low leakage current after soldering, directly helping companies reduce overall static power consumption and meet product standards.

Question Type: Reliability/Failure

Q: Automotive electronic products require near-zero defect failure rates. What quality control measures for capacitors support this requirement?

A: ymin Capacitors implements a "zero-defect" oriented end-to-end quality control system, forming a comprehensive control solution for excessive leakage current. During production, critical processes prone to damage, such as riveting, winding, impregnation, and assembly, are all equipped with CCD automatic optical inspection equipment for 100% inspection, preventing any potentially damaged semi-finished products from entering the next process.

Subsequently, through power-on aging and multiple rounds of parameter testing, products that may experience parameter degradation after reflow soldering at the customer's end are preemptively eliminated. This end-to-end control system provides a strong guarantee for achieving near-zero defect reliability in automotive electronic products.

Question Type: Performance Comparison

Q: Compared to ordinary surface-mount aluminum electrolytic capacitors, what are the advantages of Yongming polymer hybrid capacitors in resisting reflow soldering thermal stress?

A: The core difference lies in the electrolyte material—ordinary surface-mount aluminum electrolytic capacitors use liquid electrolyte, which is prone to bulging and swelling under the high temperature of reflow soldering, damaging the internal structure, leading to increased leakage current and rapid performance degradation; while Yongming polymer hybrid capacitors use an electrolyte system combining polymer solids and electrolyte, significantly reducing the risk of bulging and swelling at high temperatures and better resisting the thermal stress impact of reflow soldering.

This material advantage allows Yongming polymer hybrid capacitors to maintain stable leakage current and electrical performance after soldering, resulting in a significant improvement in reliability and lifespan compared to ordinary aluminum electrolytic capacitors.