Monday, October 28, 2013

Electronic component - Wikipedia, the free encyclopedia

Electronic component - Wikipedia, the free encyclopedia:

"An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields." 

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Friday, October 25, 2013

Bob Willis - YouTube

Bob Willis is a well known expert in the area PCB assembly.

Bob on - YouTube:

Bob's website.

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Pin in Paste Technology

ITM PIn in Paste Part 1 - YouTube:

FCI Pin in Paste Guide


Samtec's SSQ design incorporates standoffs between each tail position (.080” apart) as shown below.



The SSQ is a square tail pin which fills the inside of the hole more than a solder tail would. 

SSQ connector bodies are made from Liquid Crystal Polymer (LCP),  they are lead-free compatible. Compliant with the reflow profile parameters detailed in IPC/JEDEC J-STD-020D which requires that components be capable of withstanding a peak temperature of 260°C as well as 30 seconds above 255°C.  The parts can also withstand three reflow passes.

Stencil aperture design should be similar to that shown below, elongating the relatively narrow apertures outward from the plated through hole.  Additionally, it is highly recommended to include a ‘spoke’ emanating from the annular ring, designed to facilitate the migration of the solder paste to the plated through hole during reflow.




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Thursday, October 24, 2013

DDRx Speed

Clock Rate (MHz) is the reciprocal of Clock Cycle (nSec)

and 

Clock Cycle (nSec) is the reciprocal of Clock Rate (MHz)

DDR is defined as double data rate, which means the data bits are clocked on both the rising and falling edges of the clock. 

DDR3 with Clock Rate of 800MHz would have a Data Rate of 1600.

Example of manufacturer specs.


Monday, October 14, 2013

Footprint Recommendations - DFM

These are suggested footprints from a recent DFM report from a high volume contract manufacturer, (Second Largest CM in the World).

Note these dimensions are not per IPC-7351. These dimensions are based on experience with high volume production runs.


















Murata Caps (Murata Recommendations)






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Source Murata Datasheet

Panasonic Resistors (Panasonic Recommendations)












Source: Panasonic Datasheet


Bottom Line:  

IPC7351, Contract Manufacturers, and Component Manufacturers all have different opinions and suggestions. 

I suggest you study them all and create a universally acceptable solution that will provide high quality yields in high volume production.


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Warp and Twist


Source: Beta Layout CM - SO - 010 / D / 2010










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Friday, October 11, 2013

PCB Design Tutorials - Gold Phoenix

Tutorials_Support & Resource_Knowledge Center

"Gold Phoenix Knowledge Center is a professional interchange center in the PCB industry fields.It can provide authoritative answers  for PCB relating inquiry, and all of the participants can obtain knowledge or information, communicate technology and experience with each other, and also then establish a new understanding relationship through cooperation."

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Monday, October 7, 2013

Nickel-Gold Plating Copper PCB Traces

Source: Polar Instruments Application Note AP171

"Recently a number of customers approached us because impedance controlled tracks displayed higher losses than expected. This has been evident as the impedance test trace has sloped upwards across the tested area. While on fine line traces it is quite normal to see a gently sloping trace, the level of slope (and hence loss) was much higher than predicted — so much so that Polar decided to investigate further.  Eventually we discovered that the entire length of the trace had been nickel plated in the cases we investigated. While nickel is acceptable on short lengths of pad to accommodate gold plating, plating the whole trace length is generally not a good idea. This application note explains the effect that nickel will have on high frequency transmission lines."

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