| Electrical ratings | Operating and maximum voltage, current per circuit, signal frequency, and expected switching conditions. | Use the applicable IPC-2221 guidance for conductor spacing and electrical design. Required spacing depends on factors such as voltage, environment, and insulation conditions. | Check the circuit against the actual load, transient conditions, and any applicable product safety requirements. |
| Trace width and copper | Specify current by net, allowable temperature rise, copper weight, and whether traces carry continuous or intermittent current. | Determine conductor dimensions using the applicable design method and the selected copper thickness; do not select trace width from current alone. | Review high-current paths, connectors, vias, and local heating together. Confirm performance through analysis or testing where needed. |
| Layer count and stack-up | Define signal, power, and ground layers; board thickness; copper weights; and controlled-impedance needs, if any. | Plan conductor arrangement, spacing, and insulation within a documented stack-up that supports the electrical and mechanical design. | Confirm routing capacity, return paths, noise control, impedance targets, and availability of the proposed stack-up with the fabricator. |
| Board material | State operating temperature range, expected humidity, mechanical demands, and any flame-rating or dielectric requirements. | Select materials and construction appropriate to the board’s electrical, thermal, and environmental conditions. | Verify material properties and required certifications against the end product’s operating environment and regulatory obligations. |
| Thermal management | Identify heat-producing components, maximum component temperatures, ambient temperature, and cooling method. | Account for conductor heating and the board’s thermal design as part of the overall layout and material selection. | Assess hot spots, copper spreading, thermal vias, airflow, and enclosure effects under representative operating conditions. |
| Mechanical fit and mounting | Provide board outline, thickness, mounting-hole locations, keep-out areas, connector positions, and dimensional tolerances. | Apply the relevant design guidance to conductor placement and board features while maintaining the specified mechanical constraints. | Check enclosure fit, connector access, mounting stresses, and clearances using drawings or a physical prototype. |
| Environmental protection | Specify exposure to dust, moisture, chemicals, vibration, and temperature cycling, plus any required protective coating. | Include environmental conditions in material, spacing, and construction decisions; IPC-2221 does not by itself define every product-level qualification test. | Define suitable protection and qualification tests for the intended environment, including any required sealing or coating process. |
| Manufacturing and assembly | Set component package details, soldering process, minimum feature requirements, panelization needs, and inspection expectations. | Use design rules compatible with the chosen board construction and communicate the stack-up and fabrication requirements clearly. | Request a design-for-manufacturing review and confirm that the selected fabricator can meet the specified features and assembly process. |
| Reliability and validation | Define service life, expected duty cycle, critical failure modes, and acceptance criteria. | Use IPC-2221 as a generic printed-board design reference alongside the requirements of the finished product. | Plan appropriate electrical, thermal, mechanical, and environmental tests based on the application and applicable standards. |