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Updated February 29, 2008
The IPC-7351A LP Calculator is a fantastic time saver. It is a land pattern calculator based on the IPC-7351A SMT land pattern standard that allows you to define your
own CAD land patterns and offers seamless compatibility with the freely-distributed library documentation.
Advanced features include:
• Graphic display of component features aligned with calculated land pattern
• Compensation variables for fabrication and assembly processes
• Preset operating environments or user defined goals for land pattern toe, heel and side protrusions
• Solder joint analysis calculations
• DRC protection from overlapping lands
• Automatic land pattern name generation
 The IPC-7351A LP Calculator allows you to change the Manufacturing Tolerances that determine the pad size, Placement Courtyard Tolerance, PAD Width Round-off, Component Tolerance, Land Pattern Name, and the Solder Joint Analysis. Alternatively, you can simply use the default IPC settings, modify, and save your library documentation (using the LP Librarian or Wizard) for future retrieval.
This product provides the Pick & Place Zero Component Rotation for accurate assembly data. The JEDEC JEP95 publication and the EIA / ANSI 481 specification for tape and reel packaging was used to determine the exact component zero rotation on the assembly tape and reel or tube so that you can build all your CAD library parts in the same zero rotation to provide your vendors with accurate assembly data.
How is the IPC-7351A LP Software Beneficial?
The IPC-7351A LP Software is especially beneficial if you:
- spend more time than necessary to match up PCB components with land patterns,
- consider the current name of your land pattern to be all the documentation you need to have,
- are tired of laying parts on a 1:1 plot of your printed circuit board to verify that the land patterns you’ve selected are the right ones (if you see the difference between 0.1mm and 0.2 mm!)
- design your product with its operating environment in mind
- want to improve the bottom line by making PCB design more efficient
The IPC-7351A PCB Libraries LP Calculator is the library maintenance tool that will revolutionize the way you work. This software gives you access to options that will allow you to quickly and easily browse your PCB land pattern library to locate, view, construct and verify the mechanics of your PCB library design.
What About Alternatives?
 Like nearly everything else, there are alternatives. However, this software stands above the other "maverick" calculators and land pattern generators out there.
The first and most important reason is that we alone did not determine how the outputs are generated. Instead, we worked with IPC as the IPC-7351A standard was developed to ensure the output of this software would comply with the new standard and be accepted by the industry. Unlike alternatives, this software was produced from the ground up based entirely on the IPC-7351A as this standard was developed, which means this software does not build parts to our standard, but the IPC-7351.
Another reason our software is superior is because it perfectly dovetails with the absolutely free library documentation provided by IPC. This documentation is rapidly growing and will continually add greater value to LP software users over time. Unlike other tools created independently of IPC, this tool will meet your company's long-term library documentation needs, and provide you unprecedented compatibility with what the rest of the industry is using.
The following are target conditions for Chip, Gull-Wing, and J-Lead components. For best CAD library accuracy and quality, use the LP Calculator to achieve the best land pattern results derived from your component dimentional data or our rapidly growing library documentation. If you want to maintain your own library documentation, get the LP Librarian (includes calculator), and if you want to build parts directly to your CAD tool in less time than it takes you to key in the component dimensions, just use the LP Wizard. Building the perfect CAD library parts can't get any easier than by using the IPC-7351A LP Wizard!
The IPC-7351A 3-Tier Library System
Land patterns need an accurate Solder Joint Statistical Analysis. To help ensure that you have good solder joints regardless of what size tolerance (minimum, nominal or maximum) the components come in, use the LP Librarian. The solder joint analysis data is a must when it comes to DFA. Only the IPC-7351A LP Librarian provides you the solder joint analysis information that you need to ensure a perfect Land Pattern.
The IPC-7351A LP Calculator is in accordance with the new IPC-7351A specification. Different electronic products have different requirements for reliability, maintainability and board density. With the 3-tiered library construction concept built into the IPC-7351A LP Calculator, you can generate land patterns to meet different requirements by varying the pad and courtyard dimensions.
Three land pattern geometry variations are supplied for each of the device families; maximum land protrusion (Density Level A), median land protrusion (Density Level B) and minimum land protrusion (Density Level C). With the 3-tiered library construction concept built into the IPC-7351A LandWiz, you can generate land patterns to meet those different requirements by varying the pad and courtyard dimensions.
Here are the three different tiers and how and when you should use them:
Density Level A: Maximum (Most) Land Protrusion
For low-density product applications, the 'maximum' land pattern condition has been developed to accommodate wave or flow solder of leadless chip devices and leaded gull- wing devices. The geometry furnished for these devices, as well as inward and “J”-formed lead contact device families, may provide a wider process window for reflow solder processes as well.
Density Level B: Median (Nominal) Land Protrusion
Products with a moderate level of component density may consider adapting the 'median' land pattern geometry. The median land patterns furnished for all device families will provide a robust solder attachment condition for reflow solder processes and should provide a condition suitable for wave or reflow soldering of leadless chip and leaded gull-wing type devices.
Density Level C: Minimum (Least) Land Protrusion
High component density typical of portable and hand-held product applications may consider the 'minimum' land pattern geometry variation. Selection of the minimum land pattern geometry may not be suitable for all product use categories. The use of classes of performance (1, 2, and 3) is combined with that of component density levels (A, B, and C) in explaining the condition of an electronic assembly. As an example, combining the description as Levels 1A or 3B or 2C, would indicate the different combinations of performance and component density to aid in understanding the environment and the manufacturing requirements of a particular assembly. |
IPC-7351A LP Family System
Requirements
Minimum: MS-Windows XP (may work with Windows 2000, but we cannot guarantee this), Microsoft .NET
Framework (downloadable from Mircosoft for free), 1024 X 768 resolution
or higher, and at least 11MB of available hard drive space.
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