The first step: process design
Surface mount assembly processes, especially for tiny components, require constant monitoring of processes to see systematically. For example, in the United States, solder joint quality standards are now, according to IPC-A-620, compared to the national welding Pro standard ANSI / J-STD-001. By understanding these guidelines, designers can develop products that meet industrial standards requirements.
Mass production design
The mass production design contains all of the production constraints, procedures, assemblies, and testability, and therefore the written documentation requirements are the starting point.
A complete, clear piece of documentation is absolutely necessary and a guarantee of success in designing, manufacturing, or converting languages. The relevant documents are more detailed than the CAD data list, including the material list (BOM), the qualified manufacturer's name, the assembly details, the specific assembly instructions, and the details made by the PC board, including the Gerber data or the IPC-D-350 program on the floppy disk.
The CAD data on the floppy disk is more helpful for developing and testing than in the process of machining, writing, assembling, assembling, and so on. Which contains the X-Y axis seat extension position, test requirement, test line, summary graphics than how X-Y extension.
Assembly process development
This step covers every mechanical action, with the meat eye continuously monitored than the automated vision device. For example, it is recommended to use laser to scan the volume of paste printed on each PC board face.
In the proof on the surface mount component (SMD) and after reflow after QC than engineering personnel need to check every component on the pin to eat Pro status, each member needs a detailed record of the number of components of passive components than para multi pin. After passing through the peak welding process, it is also necessary to carefully check the uniformity of the weld pain than to determine the potential location of the defects due to the proximity of the foot or the component.
Consistent component distance
The automatic surface mount assembly machine is general and the language is rather delicate, but designers often ignore the complexity of the production process when trying to wear the components. For example, when a high component is too close to a tiny foot component, it will not only disturb the view of the weld, but also disturb the tools used in heavy or heavy work.
Ball peak welding is commonly used in relatively short, short components such as diodes and semiconductors. Small talk, components, such as SOIC, can also be used in ball peak welding, but it is important to note that sometimes scraping components are unable to withstand direct exposure to the heat of the parent furnace.
In order to ensure consistency of assembly quality, the distance between components must be large enough to appear uniformly exposed to the furnace. To ensure that solder contacts are accessible to each point, high components are required to maintain a distance from the low and short components to avoid shadowing effects. If the distance is not, it will hinder the components of view and heavy work.
Work colleagues have developed a set of standard applications in surface adhesion components. If possible, use standard components as much as possible, so that designers can build a database of standard pad sizes and use engineers to better understand process problems. The designer may find that sometimes the country has set similar standards, the components may look like pictures, but the components' pin angles vary according to the state of production.