What are the fundamental principles of PCBA design for manufacturability?
1. Optimize the use of surface mount and crimping components.
Surface mount and crimping components offer excellent manufacturability. With advancements in packaging technology, most components are now available in formats suitable for reflow soldering, including through-hole components that can be soldered via reflow methods. Achieving a design that allows for complete surface assembly significantly enhances both the efficiency and quality of the assembly process. Crimping components, particularly multi-pin connectors, also exhibit strong manufacturability and connection reliability, making them a preferred choice.
2. Considerations for PCBA assembly.
1. The package size and pin pitch are considered collectively. These factors significantly influence the overall manufacturability of the board. When selecting surface mount components, it’s essential to choose a set of packages that share similar process characteristics or are compatible with the appropriate stencil thickness for solder paste printing, especially for PCBs with specific dimensions and assembly densities. For instance, mobile phone boards require packages that are ideal for soldering and can be printed using a 0.1mm thick steel mesh.
2. Shorten the process path. A shorter process path enhances production efficiency and reliability in quality. The preferred process path design includes:
(1) Single-sided reflow soldering;
(2) Double-sided reflow soldering;
(3) Double-sided reflow soldering combined with wave soldering;
(4) Double-sided reflow soldering with selective wave soldering;
(5) Double-sided reflow soldering followed by manual soldering.
3. Optimize the component layout. The design of component layout primarily involves the arrangement and spacing of components. This layout must adhere to the requirements of the soldering process. A well-thought-out arrangement can minimize poor solder joints and tooling issues while optimizing steel mesh design.
4. Consider the pad as a whole. The design of pads for solder mask and stencil openings determines the actual distribution of solder paste and the solder joint formation process. Harmonizing the designs of the pad, solder mask, and steel mesh significantly enhances the welding yield.
5. Focus on new packaging. “New package” refers not only to newly released designs but also to packages that the company has not previously utilized. When introducing these new packages, it is crucial to conduct small-scale process verification. While others may use them, it doesn’t guarantee compatibility for your application. Thorough experiments to understand process characteristics and potential issues, along with effective countermeasures, are essential.
6. Prioritize BGA, chip capacitors, and crystal oscillators. These components are particularly sensitive to stress. During layout, avoid placing them in areas where the PCB may experience bending or deformation during welding, assembly, transportation, and use.
7. Study cases to enhance design rules. Design rules for manufacturability emerge from production practices. Continually optimizing these rules in response to instances of poor assembly or failures is vital for improving manufacturability design.
1. Optimize the use of surface mount and crimping components.
Surface mount and crimping components offer excellent manufacturability. With advancements in packaging technology, most components are now available in formats suitable for reflow soldering, including through-hole components that can be soldered via reflow methods. Achieving a design that allows for complete surface assembly significantly enhances both the efficiency and quality of the assembly process. Crimping components, particularly multi-pin connectors, also exhibit strong manufacturability and connection reliability, making them a preferred choice.
2. Considerations for PCBA assembly.
1. The package size and pin pitch are considered collectively. These factors significantly influence the overall manufacturability of the board. When selecting surface mount components, it’s essential to choose a set of packages that share similar process characteristics or are compatible with the appropriate stencil thickness for solder paste printing, especially for PCBs with specific dimensions and assembly densities. For instance, mobile phone boards require packages that are ideal for soldering and can be printed using a 0.1mm thick steel mesh.
2. Shorten the process path. A shorter process path enhances production efficiency and reliability in quality. The preferred process path design includes:
(1) Single-sided reflow soldering;
(2) Double-sided reflow soldering;
(3) Double-sided reflow soldering combined with wave soldering;
(4) Double-sided reflow soldering with selective wave soldering;
(5) Double-sided reflow soldering followed by manual soldering.
3. Optimize the component layout. The design of component layout primarily involves the arrangement and spacing of components. This layout must adhere to the requirements of the soldering process. A well-thought-out arrangement can minimize poor solder joints and tooling issues while optimizing steel mesh design.
4. Consider the pad as a whole. The design of pads for solder mask and stencil openings determines the actual distribution of solder paste and the solder joint formation process. Harmonizing the designs of the pad, solder mask, and steel mesh significantly enhances the welding yield.
5. Focus on new packaging. “New package” refers not only to newly released designs but also to packages that the company has not previously utilized. When introducing these new packages, it is crucial to conduct small-scale process verification. While others may use them, it doesn’t guarantee compatibility for your application. Thorough experiments to understand process characteristics and potential issues, along with effective countermeasures, are essential.
6. Prioritize BGA, chip capacitors, and crystal oscillators. These components are particularly sensitive to stress. During layout, avoid placing them in areas where the PCB may experience bending or deformation during welding, assembly, transportation, and use.
7. Study cases to enhance design rules. Design rules for manufacturability emerge from production practices. Continually optimizing these rules in response to instances of poor assembly or failures is vital for improving manufacturability design.
