| Feature | IPC-7351 (Old) | IPC-7352 (New) | | :--- | :--- | :--- | | | Complex three-tier system (e.g., SOP65P640X120-45N ) | Simplified, more intuitive naming (e.g., SOP_0.65mm_P_64L ) | | Calculator Methodology | Absolute dimensional limits | Statistical (nominal) plus assembly allowances | | Thermal Management | Basic pad design | Enhanced for reflow and wave soldering defects | | Density Levels | Least, Nominal, Most (A, B, C) | Now integrated into three distinct levels: High Density, Standard, and Low Density | | Tombstoning Prevention | Limited guidance | Specific geometry rules to prevent small passive components from standing upright |
The document is roughly 56 pages long and covers a wide array of component families:
: Lists the standard as a Generic Guideline for Land Pattern Design with monthly status updates for members. IPC Standard Hierarchy Comparison Feature IPC-7351B (Legacy) IPC-7352 (Current) Status Standard (Requirements) Guideline (Recommendations) Release Date Naming Style Pin Qty often moved Pin Qty at the end Usage Foundation for many CAD libraries Modern DFM (Design for Manufacturability) Buy IPC-7352 in PDF & Print | Nimonik Standards
Here are the key differences:
Enter . Released by the IPC 1-13 Land Pattern Subcommittee, this modern standard replaces obsolete methodologies and establishes a unified approach to land patterns for both surface-mount and through-hole electronic components . 1. What is IPC-7352?
: Many engineering firms provide access via enterprise subscriptions to standards aggregators.
is the premier global standard governing land pattern (footprint) design for both surface mount devices (SMD) and plated through-hole (PTH) electronic components . Released by the IPC 1-13 Land Pattern Subcommittee , this document supersedes previous methodologies to align modern PCB library creation with cutting-edge assembly and inspection rules. Electronic designers, ECAD librarians, and manufacturing engineers utilize the IPC-7352 PDF to establish uniform, mathematically validated footprints that ensure high-yield, reliable solder joints. 1. What is IPC-7352? Ipc-7352 Pdf
: General-purpose design for standard density.
Instead of memorizing these, most engineers use the standardized in Appendix A of the PDF. For example, for a 0402 resistor (1.0mm x 0.5mm):
The standard is built around the fundamental solder joint goals for a component's leads, defined as the , Heel , and Side (or Periphery for grid array components). The Toe is the portion of the land pattern extending beyond the end of the lead, the Heel is the portion under the lead, and the Side is the portion along the width of the lead. The "solder joint goal tables" within the IPC-7352 PDF provide recommended values for these three elements, which are essential for generating the pad size and spacing for a land pattern. These tables are often broken down into three density levels: Least , Nominal , and Most (often colloquially referred to as 'L', 'M', and 'N'), providing designers with options to suit different manufacturing requirements and tolerance needs. | Feature | IPC-7351 (Old) | IPC-7352 (New)
IPC-7352 provides the mathematical formulas and rules for calculating land patterns based on component dimensions. It ensures that your PCB footprints are optimized for solder joint reliability, manufacturability, and testing. Key Highlights of the New Standard:
: Unlike its predecessors, IPC-7352 integrates specific guidelines for through-hole technology alongside surface-mount design. Электрохимический портал Relationship to Other Standards
subgraph Assembly_Standards [Assembly & Soldering] D[IPC J-STD-001<br>Soldering Requirements] end is the premier global standard governing land pattern