Posted Mar 31, 2011, by Tom Hausherr
Here are some tips about Metric Speak that all PCB designers need to know. “Metric” is not a unit of measure. Metric is a term that describes a measurement system. You use either millimeters or microns for your PCB design units. The proper terminology to describe your working units when using the metric measurement system is millimeters or microns, not metric. Example: When doing PCB layout in Inches … Read More
Tags:
Padstack,
CAD Library,
PCB Grid
Posted Jan 21, 2011, by Tom Hausherr
0.5 mm Pitch BGA Routing Solution
There is a reasonable solution for via fanout and a routing solution for the 0.5 mm pitch BGA but we need to think outside the box. The board thickness is an important factor because it affects the hole plating aspect ratio. If you use a 1 mm PCB thickness and want to achieve a 7:1 aspect ratio (this is common among all manufacturers) then the smallest hole size … Read More
Tags:
CAD Library,
BGA
Posted Jan 14, 2011, by Tom Hausherr
CAD Library Zero Component Orientations
In 2005 IPC and IEC (International Electrotechnical Commission) established a joint standard for land pattern geometries (IPC-7351/IEC 61188-5-1). In order to maintain a consistent method where these two important standards describe the component mechanical outlines, and their respective mounting platforms, a single concept must be developed that takes into … Read More
Tags:
IEC Standards,
IPC Standards,
CAD Library
Posted Jan 8, 2011, by Tom Hausherr
The BGA or Ball Grid Array has been around since the 1980’s but the pin pitch started out with 1.5 mm and then quickly went to 1.27 mm (50 mils) for about 15 years. Then in the late 1990’s, the 1 mm pitch BGA was introduced and every couple years a smaller pin pitch was introduced. Today 0.4 mm pitch BGA’s are in every cell phone and 0.3 mm pitch BGA’s are the next generation. … Read More
Tags:
CAD Library,
BGA
Posted Nov 18, 2010, by Tom Hausherr
Placement Courtyards
I promised to post “The Anatomy of a Land Pattern” in Part 6 of my blog, but the subject must be broken down into mini-blogs as the topic covers too many issues. So let’s start with the IPC-7351B “Placement Courtyard”.
The IPC-7351B standard only focuses on 2 two major aspects of the CAD library:
The land size and spacing
Placement courtyard
All … Read More
Tags:
CAD Library
Posted Oct 1, 2010, by Tom Hausherr
Molded Body Components
The next most popular component family on a PCB design layout is the Molded Body Tantalum Capacitor (CAPM). The CAPM components have an “L-Bend” component lead form. Most Molded Body Tantalum Capacitors are metric by default including their standard EIA names –
3216 – 3.2 mm X 1.6 mm
6032 – 6.0 mm X 3.2 mm
7243 - 7.2 mm X 4.3 mm
7343 – 7.3 mm X 4.3 mm
The … Read More
Tags:
library tools,
CAD,
CAD Library
Posted Jul 8, 2010, by Tom Hausherr
I'm curious as how do PCB designers route metric pitch BGA's on a mil grid system or gridless (which consumes memory and CPU)? I can't figure why anyone would use a mil grid system for any PCB CAD library construction or PCB design layout when all the SMT component manufacturers are only producing metric pin pitch packages. This is where we note that all chip resistors and capacitors are dimensioned … Read More
Tags:
CAD Library,
BGA
