Browse Topic: Soldering
With rising environmental concerns, developing lead-free solders is crucial for sustainable electronics. Traditional lead-based solders, while effective, pose health and environmental risks, prompt a shift to safer alternatives that retain reliability. Sn-9Zn alloys, when alloyed with elements such as cerium (Ce) and chromium (Cr), show enhanced mechanical and thermal properties suited for modern electronics. This study examines the effects of Ce and Cr, and their combination in Sn-9Zn solder alloy, analyzing improvements in microstructure, thermal, wettability, and hardness properties. Microstructural analysis reveals that Ce and Cr additions refine the alloy’s structure, benefiting performance. Wettability testing shows that Sn-9Zn-0.05Ce achieves the lowest wetting angle, while Sn-9Zn-0.05Ce-0.1Cr displays a balanced angle between Sn-9Zn-0.05Ce and Sn-9Zn-0.1Cr. Differential scanning calorimetry (DSC) results indicate that Sn-9Zn-0.05Ce has the lowest melting temperature, while Sn-9Zn-0.1Cr has the highest, with Ce and Cr together reducing the melting temperature by 2.83°C from the peak in Sn-9Zn-0.1Cr. Apart from this, the Vickers microhardness test reveals the highest hardness in Sn-9Zn-0.05Ce-0.1Cr with 19.62 HV, underscoring the strengthening effects of Ce and Cr. The outcomes suggest Ce and Cr alloying as a promising approach to enhance the performance of lead-free solders in eco-friendly electronics.
Repartly, a startup based in Guetersloh, Germany, is using ABB’s collaborative robots to repair and refurbish electronic circuit boards in household appliances. Three GoFa cobots handle the sorting, visual inspection and precise soldering tasks enabling the company to enhance efficiency and maintain high quality standards.
An electronic assembly is created by integrating thousands of parts from multiple suppliers utilizing a host of circuit card manufacturing processes. With the lead elimination from electronics resulting from the European Union Reduction of Hazardous Substances (RoHS) legislation, many of the heritage aerospace and defense commercial off the shelf (COTS) solder materials with tin–lead have become obsolete. Most notably there has been an increasing cost and schedule pressure to use commercially available pure tin part finishes and lead–free solders in aerospace and defense electronic systems.
In the circuit board industry, an increasing number of parts and boards are proving to be difficult to inspect with automated optical inspection (AOI) because the solder is invisible. Furthermore, high-quality requirements such as bonding strength of the automobile industry and full surface inspection of the solder are increasing. To address these needs, Omron has introduced new technology for accomplishing inspections within the required inline take time (the rate at which a product must be completed to meet customer demand). This has been one of the most challenging requirements for computed tomography (CT) X-ray automatic inspection equipment. For continuous imaging technology, highly accurate positioning control and high-speed image sensing are required.
Rosin is a naturally available organic material obtained especially from pine trees. It finds many usages and applications in areas like soldering, pharmaceuticals, building work, engineering field etc. In this work, an attempt has been made to study experimentally the improvement in strength of rosin at normal stove top temperature by means of combining rosin in various ratios with some important organic hardeners and chemicals of literature importance. A table top book press was fabricated for the purpose of rosin pressing using simple tools like teak wood, bolt and nuts. Experiments were conducted using commonly used kitchen gas stove, fabricated book press, rosin raw material, aluminium sulfate powder, maleic anhydride chemical, acetone, ethanol and saw dust particles for making different combination materials using rosin as the main element. Results showed that, rosin on its own without additives showed higher viscosity and brittleness. When combined with organic hardener aluminium sulfate, rosin produced an improved material with reduced brittleness, good hardness and good energy absorption. And by combining with maleic anhydride chemical, rosin produced a hard monomer with an improvement in energy absorption with better future scopes. Comparatively better material was obtained using saw dust particle reinforced rosin and chemical hardener combination. Improvement in characteristics like viscosity and energy absorbed were observed using experiments at three different temperatures. With this improvements, rosin promises to be a possible future material or material additive like filler in composites with regard to anti-plastic materials or plastic alternatives.
Reliability states the degree to which the result of a measurement, calculation, or specification can be depended on to be accurate. And, tests according to GM specifications represents a minimum of 15 years of vehicle life time with defined Reliability and Confidence level. In this work, actual number of thermal cycles for Thermal Fatigue tests (Thermal Shock and Power Temperature Cycle) are calculated for Copper Wire whose Coffin Manson exponent is 5. Overstressing the PEPS Antenna under thermal fatigue requirement (defined number of thermal cycles based on Reliability and Confidence requirements) will lead to broken Copper wire which will result in component’s functional failure and thus impossible to continue reliability testing. The objective of this paper is to determine thermal fatigue requirements for Antenna’s Copper wire whose Coffin Manson exponent is 5. Testing with exact number of thermal cycles will reduce the validation failures owing to broken Copper wire and thus save incurred revalidation cost. The current study is limited to only adjusting the thermal fatigue requirements (Number of Thermal Cycles) for only specific E/E components having Copper wire soldered directly on to the PCBA. The limitation of validation experiment is to choose the correct Coffin Manson exponent for achieving desired number of thermal cycles for all specific E/E components having Copper wire soldered directly on to the PCBA. Conclusion- Derived appropriate thermal fatigue cycles (22% of actual total number of 100% cycles) for Copper material with Coffin Manson exponent of 5 will reduce the failure associated with the broken Copper wire and thus will save the revalidation cost.
Industry consensus developed IPC standards for the automotive electronics manufacturer have been available since 2016. We will look at the current IPC standards available in development and in revision, the standards development process, and the automotive application addendums for printed board fabrication and assembly soldering that provide unique criteria for the reliability of electronic interconnects that must survive the harsh environments within the automotive industry. Attention will be given to a new effort in development to provide links between existing automotive-centric IPC standards and other industry standards applicable to automotive applications for printed board material selection, design, and solder joint reliability testing. We will also discuss challenges facing the industry, including process changes and cleanliness requirements, e.g. ionic contaminants, that affect every manufacturer and customer.
This research proposes a third-generation power control unit (PCU) for a two-motor hybrid system. To make a more compact intelligent power unit (IPU) to be located under the second seat, a PCU with a 12-volt DC-DC converter (DCDC) that mounts directly on the transmission was developed, whereas the DCDC was previously mounted within the IPU. Since this has a considerable impact on the engine room layout, the technology described below was used to make the PCU even more compact than the second-generation unit. The power module, a key component of the PCU, now uses Ag nanoparticles sintering bonding rather than conventional solder bonding. This helps lower thermal resistance and enables smaller power semiconductors. The voltage control unit (VCU) has a new circuit that uses a multi-stage switching circuit and electric power transfer capacitor instead of the conventional chopper circuit. This makes it possible to shrink the reactor to less than 65% of its usual volume without raising the carrier frequency, and enables a layout that efficiently uses both sides of the water jacket (W/J), so that no specially designed W/J needs to be added just for the DCDC. As for the W/J seal, friction stir welding (FSW) to increase rigidity was used to reduce seal width and to make the W/J itself more compact. The use of these compactness technologies enabled the PCU to maintain all the efficiency of a second-generation PCU and made it possible to build the DCDC in the PCU with its volume less than a second-generation one. Development of this PCU makes the IPU much more compact and provides a similar amount of trunk space as in a gasoline-powered vehicle.
The huge demand for switching components exceeding silicon's (Si) current density limitation of 200 A/cm2 has pushed the enhancement of alternative semiconductor materials such as silicon carbide (SiC), gallium nitride, and diamond. The enhanced material properties of SiC, such as high thermal conductivity, large critical field, wide bandgap, large elastic modulus, and high saturation velocity, make it a viable candidate for pulsed power systems. Using SiC would increase both current and power densities, improve dI/dt and dV/dt capabilities, reduce recovery time, and minimize switching losses in various power electronic systems. Furthermore, a significant reduction in the volume and weight of pulsed power systems can be realized by implementing SiC SGTOs, reducing the thermal management requirements of the pulsed power system.
Power modules are used to operate three-phase alternating current motors in hybrid vehicles and electric vehicles. Good fuel efficiency and high power density are required in the field of hybrid vehicles. To achieve this goal, the miniaturization of the power module will be necessary. This trend may make a current density, which is created by insulated gate bipolar transistors (IGBTs) and free wheel diodes (FWDs), higher in power modules. Solder is often used as the joint material of power modules. It is known that a current density larger than 10 kA/cm2 causes solder electromigration. This phenomenon may cause delamination of the joint area. In addition, the ambient temperature has an influence on electromigration. The temperature of an engine compartment is high, so it is likely to cause electromigration. However, the current density of the double-sided cooling power modules in 2007 with solder joint is lower than 0.4 kA/cm2, and this value is lower than 10 kA/cm2. This current density is not so severe to the solder joint system. Black’s equation shows that current density and the temperature have an effect on the mean time to failure (MTTF). We investigated mechanisms of electromigration when applying a current density lower than 10 kA/cm2. In this research, the solder joint system was composed of Ni plating/Sn-0.7Cu. The diffusion ratio of Ni was different between the cathode side and the anode side. The diffusion ratio of the cathode side was higher than that of the anode side. In addition, the thickness of the intermetallic compound (IMC) was larger at the anode side than that at the cathode side. The electromigration of Ni plating/Sn-0.7Cu based joint system with a current density lower than 10 kA/cm2 was clarified.
For the purpose of improving vehicle fuel efficiency, it is necessary to reduce energy loss in the alternator. We have lowered the resistance of the rectifying device and connecting components, and control the rectifying device with an IC to reduce rectification loss. For the package design, we have changed the structure of the part on which the rectifying device is mounted into a high heat dissipation type. The new structure has enabled optimizing the size of the rectifying device, resulting in the reduction of size of the package. In addition, the rectifying device is mounted using a new soldering material and a new process, which has improved the reliability of the connection. Moreover, since the alternator has introduced a new system, the controller IC has a function for preventing malfunction of the rectifying device and a function for detecting abnormalities, in order to ensure safety. These technologies have realized a low-energy loss high-reliability rectifier, which contribute to the reduction of alternator loss and enhancement of vehicle fuel efficiency.
Iowa State engineers have developed micro-sized liquid-metal particles for heat-free soldering and metal processing applications.
The use of Micro Electro-Mechanical Systems (MEMS) for measuring accelerations, pressure, gyroscopic yaw rate and humidity in engine controls, inflatable restraint, braking, stability and other safety critical vehicle systems is increasing. Their use in these safety critical systems in high stress automotive environments makes ensuring their reliability and durability essential tasks, especially as the Vehicle System Functional Safety requirements of ISO-26262 are being implemented across the industry. A Design for Reliability (DfR) approach that applies Physics of Failure methods to evaluate and eliminate or mitigate susceptibilities to failure modes of a device during the design of a product is the most effective and efficient way to achieve Functional Safety levels of reliability-durability. MEMS packages exhibit several failure modes that can be predicted as a device is designed using modern Computer Aided Engineering (CAE) software tools. This paper provides a methodology for using the Sherlock ADA CAE APP to rapidly create a high-fidelity model of a MEMS interposer with all the conductor geometries. The two failure modes that are explored with this model are: Package warpage due to copper imbalance between the two sides of the MEMS interposer. If a Coefficient of Thermal Expansion (CTE) mismatch due to copper imbalance exists between the two sides, bending of the package can occur to such a degree that it becomes impossible to assemble the solder interconnects. Filled microvia delamination that can occur when the filled microvias have copper structures that can delaminate from the copper traces in the conductor layers. High-fidelity CAE modeling where each layer can be meshed based on the actual geometry of the layout of a MEMS device provides a predictive tool that allows designers to optimize the design to balance the layout without the need for costly and time consuming manufacture and testing of prototype parts.
Items per page:
50
1 – 50 of 207