Layout Guidelines
=================

Land pattern
------------

.. figure:: ../images/concept/qs-pad.png
   :figwidth: 25%
   :align: right
   :alt: QS Land Pattern
   
   100 pin QS Land Pattern

.. figure:: ../images/concept/qs-qsx-pad.png
   :figwidth: 25%
   :align: right
   :alt: QS and QSX Common Land Pattern
   
   100 pin Common Land Pattern

.. figure:: ../images/concept/qsx-pad.png
   :figwidth: 25%
   :align: right
   :alt: QSX Land Pattern
   
   108 pin QSX Land Pattern
   
The five 1mm pads in the square GND pad cutout can be omitted.

Solder Mask
-----------

.. figure:: ../images/concept/qsx-mask.png
   :figwidth: 25%
   :align: right
   :alt: QSX Solder Mask

   QSX Solder Mask
   
.. figure:: ../images/concept/qs-mask.png
   :figwidth: 25%
   :align: right
   :alt: QS Solder Mask
   
   QS Solder Mask

.. figure:: ../images/concept/qs-back2.png
   :width: 40%
   :figwidth: 30%
   :align: left
   :alt:


The ground pad solder mask on the bottom side of the QS module is divided into sections. 

GND Vias
--------

.. figure:: ../images/concept/qs-via.png
   :figwidth: 25%
   :align: right
   :alt:

If the via holes used on the application board have a diameter larger than 0.3 mm, 
it is recommended to mask the via holes to prevent solder wicking through the via holes. 
Solders have a habit of filling holes and leaving voids in the thermal pad solder junction, 
as well as forming solder balls on the other side of the application board which can in some 
cases be problematic. The 0.7mm wide solder mask stripes can be used to arrange the vias.