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Here you can find knowledge about Cold Solder Prevention, including but not limited to usage methods, installation techniques, troubleshooting and more. Focused on SMT soldering processes. If you can't find what you need, please contact us anytime.
Insufficient flux activity in solder paste will significantly weaken its ability to remove oxide films, leading to poor pad wetting after solder paste printing and insufficient solder spreading during reflow, which ultimately causes cold solder joints in the solder paste. This issue is particularly prominent in 0201/01005 micro components, OSP surface-treated PCBs, and low-temperature reflow processes, requiring coordinated verification from three aspects: flux acid value, halogen content, and activation temperature window.
Published: 2020-09-21Cold solder joint is one of the most frequent soldering defects on SMT production lines. Pad oxidation and insufficient flux activity are the two main causes: the former prevents solder paste from wetting the copper surface, while the latter makes the oxide film difficult to remove. When the two factors overlap, the incidence of cold solder joint can increase by more than 3 times. The Jiajinyuan JHY-805 series flux has a measured wetting angle of <25° on OSP boards, effectively suppressing the formation of cold solder joints.
Published: 2018-05-09Cold soldering is one of the most stubborn soldering defects in SMT production of large thick copper boards, occurring frequently especially on PCBs with copper thickness ≥2oz and dimensions ≥400mm×300mm. The root cause is that the large heat capacity of the copper substrate and delayed temperature rise lead to insufficient solder paste reflow. In production line tests, Jiajinyuan cold soldering repair paste can reduce the cold soldering defect rate from 1.8% to below 0.3%.
Published: 2018-02-07Cold solder joints with rough surfaces, poor mechanical strength, and susceptibility to fracture failure are a high-frequency failure mode in SMT production lines. The root causes are insufficient melting of the solder paste, inadequate flux activity, or low reflow peak temperature. For Jia Jinyuan solder paste on 0.3mm fine-pitch QFN devices, if the reflow peak temperature is below 217°C, batch cold soldering leading to weak solder joints with thrust below 8gf is highly likely to occur.
Published: 2018-01-01Cold solder joints are almost impossible to identify visually with the naked eye or via conventional AOI, and must be exposed through power-on testing and thermal stress excitation. Their essence is the absence of continuous metallurgical bonding between the solder joint metals, leading to signal transmission interruption, abnormal temperature rise, and intermittent failures. Statistics from the JJY production line show that 73% of customer returns caused by cold solder joints occur after 48 hours of complete machine aging.
Published: 2017-01-15
Cold solder joints caused by solder wire are a high-frequency root cause of failures on SMT production lines. They are neither a simple material defect nor a single process control failure, but rather the result of coupled mismatches among multiple variables, including solder wire activity, wire diameter tolerance, flux residue, soldering iron temperature, wire feed rhythm, and solder joint wetting time. Typical manifestations include a dull solder joint surface without metallic luster, a thrust test result below 50gf, and an internal void rate exceeding 15% visible under X-ray inspection.
Published: 2016-12-07Manual soldering is a key process for repair soldering and rework on SMT production lines. Novices often cause defects such as cold solder joints and solder spikes due to improper temperature control, excessive solder joint dwell time, or incorrect selection of soldering tip types. Based on twenty years of practical experience on the Jiajinyuan production line, this paper focuses on pre-soldering preparation, soldering iron parameter setting, solder joint operation rhythm, and common defect attribution, directly addressing the core operational details that affect the first-pass yield.
Published: 2015-02-11In circuit board soldering, cold solder joints, solder beads, and voids are high-frequency defects on production lines, directly affecting first-pass yield and long-term reliability. Based on 20 years of practical data from the Jiajinyuan SMT production line, this paper focuses on key intervention points such as solder paste printing accuracy, dynamic matching of reflow profiles, stencil aperture optimization, and nitrogen concentration gradient control, and provides immediately implementable parameter adjustment combinations and failure reproduction verification methods.
Published: 2014-05-14Cold solder joints manifest as a lack of intermetallic compound layer between component pins and PCB pads, resulting in poor electrical conduction and insufficient mechanical strength. This defect is commonly observed in actual production line conditions such as insufficient peak reflow temperature, reduced solder paste activity, or severe pad oxidation. For Jiajinyuan solder paste, intensified flux volatilization after continuous printing for over 4 hours will significantly increase the incidence of cold solder joints.
Published: 2013-11-03Ball mounting process yield control should focus on solder paste printing consistency, stencil tension stability, and reflow profile matching. By monitoring squeegee pressure fluctuations in real time, optimizing the vacuum suction parameters of the ball mounting machine, and calibrating visual positioning offsets, the incidence of cold solder joints and solder ball misalignment can be significantly reduced. On Jiajinyuan's production line, the measured defect rate per batch of ball mounting was reduced from 0.87% to 0.23%. The key lies in coupling all stages of the ball mounting process into a closed-loop feedback system.
Published: 2012-11-16Our technical team is always ready to provide professional solder material selection advice and SMT process solutions.