PCBA Tech - SMT STEP BY STEP (SMT Ten Steps)

Product design for manufacturing in one step

Over the years, although DFM has been defined in various ways, a basic concept is the same: In order to achieve high possible output with a short cycle and low cost in the manufacturing stage, DFM must be based on the concept of new product development. The stage has specific performance.

Two-step process control

With the rapid development of the Internet and e-commerce, which have a strategic position in the sales market, OEMs are facing an increasingly fierce competition. The time for product development and market placement is dramatically shortening, and the pressure on marginal profits has actually increased. At the same time, contract processors (CM) found that customer requirements are increasing: production must be qualified and licensed, and the electronic components on the product must be effective and traceable. In this way, the archiving of files has become indispensable.

Three-step welding materials

Solder is used as the connection material for all three levels of connection: die, package, and board assembly. In addition, tin/lead (tin/lead) solder is usually used for component pins and PCB surface coating. Taking into account the technical effects and adverse effects of lead (Pb), smtsh.cn/target=_blank class=infotextkey>Shanghai smt solder can be classified as lead-containing or lead-free. Nowadays, feasible surface coating materials for components and PCBs that can replace tin/lead materials have been found in lead-free systems. However, the search for connection materials and the actual lead-free system is still in progress. Here, summarize the basic knowledge of tin/lead soldering materials and the performance factors of solder joints, and then briefly discuss lead-free solder.

Four-step solder paste printing (silk printing)

In the reflow soldering of surface mount assembly, the solder paste is the connecting medium between the component pin or terminal and the pad on the PCB circuit board. In addition to the solder paste itself, there are various factors in the screen printing, including the screen printing machine, the screen printing method and the various parameters of the screen printing process. The silk screen process is the focus.

Five Steps Adhesive/Epoxy Adhesive and Epoxy

The density of the adhesive, good glue point profile, good wet state and curing strength, and glue point size must be clearly specified. Use CAD or other methods to tell the automatic equipment where to dispense glue. The dispensing equipment must have appropriate accuracy, speed and repeatability to achieve a balance of application costs. Some typical glue dispensing problems must be anticipated during process design.

Six steps to place components

Today's surface mount equipment must not only be able to accurately place various components, but also be able to handle increasingly smaller component packaging. The equipment must maintain its mobility to adapt to new components that may become mainstream in electronic packaging. Equipment users-OEM and CM-are facing exciting times. The key to success lies in the ability of SMT equipment suppliers to meet customer requirements and deliver products in a short period of time.

Seven steps welding

Batch reflow soldering, process parameter control, effect of reflow temperature curve, nitrogen protection reflow, temperature measurement and optimization of reflow temperature curve.

Eight steps cleaning

Cleaning is often described as a "non-value added" process, but is this realistic? Or it is too simplified to prevent careful thinking of complex things. Without reliable products and low costs, a company cannot survive in today's global economy. Therefore, every step in the manufacturing process must be carefully checked to ensure that it contributes to the overall success.

Nine-step test/inspection

The choice of test and inspection strategy is based on the complexity of the board, including many aspects: surface mount or through-hole plug-in, single-sided or double-sided, number of components (including dense feet), solder joints, electrical and appearance characteristics, here, the focus Focus on the number of components and solder joints.

Ten steps to rework and repair

Instead of treating rework as a "necessary misfortune," enlightened managers understand that the combination of the right tools and improved technician training can make rework an efficient and cost-effective step in the entire assembly process.

The above is the introduction of SMT STEP BY STEP. Ipcb is also provided to PCB manufacturers and PCB manufacturing technology.