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As the solder joints are somewhat less malleable, mechanical shock of joints should be avoided."Over the past 80 years, Mobil Delvac has been protecting and helping extend the lives of heavy duty engines for owner operators and fleet managers around the world," said Lawrence. "Today, with the launch of Mobil Delvac Extended Life Coolant/Antifreeze, our flagship Mobil Delvac brand now includes a full line of lubricants, greases, powertrain fluids and coolants."As standard Pb-free compatible laminate properties are still being developed, the laminate must be described clearly, lest the vendor ship material that is not compatible with the process. PWB cleanliness upon delivery should be defined, too. Post-soldering residue is expected to increase; thus the cleanliness of incoming material will be valuable. Only then will a no-clean process be attainable (we propose at least 50% of the former MIL-spec value.)Eutectic BiSn-solder can be modified by adding small percentages of other metals.Quality assurance. Next, engage the quality assurance department. Much needed information should be available there. In particular, you will find out what happens to goods received. Ideally, the understanding of quality resides at the vendor. Regular meetings, discussions and quality audits at the vendor's place can ensure a high level of product quality.Name of Product: Soldering iron, model CL-3--Cummins 14603;About Underwriters LaboratoriesProcedures. Start by describing--with the production line as the backdrop--all relevant parameters used in the present production environment. As a second step, include incoming materials. Finally, in a general sweep, encompass purchasing and engineers and layout personnel.Mobil Delvac Extended Life Coolant/Antifreeze meets or exceeds all major OEM and industry coolant specifications, including:Identification: Marked with "6G98," "MODEL CL-3," "E190243" and the UL
Listing Mark for the United States and Canada.ExxonMobil, Mobil, and Delvac are registered trademarks of Exxon Mobil Corporation or one of its subsidiaries.* The maximum temperature at which the resulting product is used must be below 100[degrees]C.--Mercedes DBL 7700."For fleet managers, owner operators, or any company specializing in off-highway applications, such as agriculture and construction, Mobil Delvac Extended Life Coolant/Antifreeze becomes a valuable tool to enhancing engine durability and reduce maintenance costs," said Valencia Lawrence, ExxonMobil Lubricants & Specialties.What You Should Do: UL recommends that users stop using the product
immediately and return it to the place of purchase.Quantity: 2000 unitsCompanies have to make sure workers remain in tune with technical requirements. When switching from Pb-bearing to Pb-free solders, keeping personnel informed is of utmost importance. The latest information has to be shared. The system of communication must be flexible to cope with the glut of information stemming from the introduction of several solder alloys.Update documentation to reflect the present situation. Check whether ISO 9000 documents from the last certification still show the values as displayed on the equipment. Sometimes the machine operator changes the settings to improve the process and its results.Underwriters Laboratories Inc. (UL) is an independent, not-for-profit
product safety certification organization that has been testing products
for more than 110 years. UL tests more than 19,000 types of products
annually, and more than 19 billion UL Marks appear on products each year.
Worldwide, UL's family of companies and its network of service providers
include 58 laboratories, and testing and certification facilities.Some use these solders at pot temperatures of 255[degrees]C. This may be marginally acceptable for product that is not thermally demanding. However, the literature shows such temperatures are unrealistic for complicated or heavy assemblies. Experiments of low temperatures sidestep problems that can arise due to high application temperatures. When capping the temperature at 255[degrees]C, leaching of 316 or even 305 steels is much less and the amount of dross generated will also be less. The preheat temperature will not need to be raised to the same degree as when one has to enter into a 285[degrees]C solder flow. Indeed, many things are possible in a laboratory environment that will never work in production situations. It is not surprising that a number of experiments have taken place and reported that the results with 255[degrees]C solders are acceptable or even "good." In production, we cannot expect that such "fiddling" will be successful and that acceptable defect rates and reliability would be attainable for demanding products. In our opinion, a high level of touch-up and repair will automatically put an end to such day-dreaming or intentional whitewashing.Do not hesitate to extend the fishbone diagram into areas such as purchasing, design and layout.What does QA really test? Is it simply the value of components and their dimensions, or does is include important process aspects such as solderability, component humidity absorption, thermal properties or even actual tests of the surface finish of boards and components? If not all requirements are already met, a lot of work may be in store; for high reliability and low levels of process defects, production will need to know much of the aforementioned information.Processes. Processes can be visualized in many different ways. A fishbone (Ishikawa) diagram depicts the steps to be performed and routes taken to ensure the production line operates properly. A good idea, perhaps, would be to take such brain-storming sessions farther, as many cost factors that impact production derive from such points as design and layout or purchasing. These sources of problems may become more marked as Pb-free processes are introduced. Although information is just coming out about what land patterns will optimize manufacturability and reliability, certain measures must be taken: e.g., it is highly recommended that assemblies exhibit better thermal equilibrium between the different parts.
Some use these solders at pot temperatures of 255[degrees]C. This may be marginally acceptable for product that is not thermally demanding. However, the literature shows such temperatures are unrealistic for complicated or heavy assemblies. Experiments of low temperatures sidestep problems that can arise due to high application temperatures. When capping the temperature at 255[degrees]C, leaching of 316 or even 305 steels is much less and the amount of dross generated will also be less. The preheat temperature will not need to be raised to the same degree as when one has to enter into a 285[degrees]C solder flow. Indeed, many things are possible in a laboratory environment that will never work in production situations. It is not surprising that a number of experiments have taken place and reported that the results with 255[degrees]C solders are acceptable or even "good." In production, we cannot expect that such "fiddling" will be successful and that acceptable defect rates and reliability would be attainable for demanding products. In our opinion, a high level of touch-up and repair will automatically put an end to such day-dreaming or intentional whitewashing.
Author: Markus Walter
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