CY7C68013A/CY7C68014A
CY7C68015A/CY7C68016A
from the thermal pad to the PCB inner ground plane by a 5 x 5
array of via. A via is a plated through hole in the PCB with a
finished diameter of 13 mil. The QFN’s metal die paddle must
be soldered to the PCB’s thermal pad. Solder mask is placed
on the board top side over each via to resist solder flow into
the via. The mask on the top side also minimizes outgassing
during the solder reflow process.
Figure 14-1 below displays a cross-sectional area underneath
the package. The cross section is of only one via. The solder
paste template needs to be designed to allow at least 50%
solder coverage. The thickness of the solder paste template
should be 5 mil. It is recommended that “No Clean” type 3
solder paste is used for mounting the part. Nitrogen purge is
recommended during reflow.
For further information on this package design please refer to
the application note Surface Mount Assembly of AMKOR’s
MicroLeadFrame (MLF) Technology. This application note can
be downloaded from AMKOR’s website from the following
URL
Figure 14-2 is a plot of the solder mask pattern and
Figure 14-3 displays an X-Ray image of the assembly (darker
areas indicate solder).
http://www.amkor.com/products/notes_papers/MLF_AppNote
_0902.pdf. The application note provides detailed information
on board mounting guidelines, soldering flow, rework process,
etc.
0.017” dia
Solder Mask
Cu Fill
Cu Fill
0.013” dia
PCB Material
PCB Material
Via hole for thermally connecting the
This figure only shows the top three layers of the
circuit board: Top Solder, PCB Dielectric, and
the Ground Plane
QFN to the circuit board ground plane.
Figure 14-1. Cross-section of the Area Underneath the QFN Package
Figure 14-2. Plot of the Solder Mask (White Area)
Figure 14-3. X-ray Image of the Assembly
Purchase of I2C components from Cypress, or one of its sublicensed Associated Companies, conveys a license under the Philips
I2C Patent Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification
as defined by Philips. EZ-USB FX2LP, EZ-USB FX2 and ReNumeration are trademarks, and EZ-USB is a registered trademark,
of Cypress Semiconductor Corporation. All product and company names mentioned in this document are the trademarks of their
respective holders.
Document #: 38-08032 Rev. *K
Page 59 of 60
© Cypress Semiconductor Corporation, 2006. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress product. Nor does it convey or imply any license under patent or other rights. Cypress products are not warranted nor intended to be
used for medical, life support, life saving, critical control or safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress does not authorize its
products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges.
[+] Feedback
CYPRESS [ CYPRESS ]
