CY7C64714-128AXC Cypress Semiconductor Corp, CY7C64714-128AXC Datasheet - Page 48

• Manufacturer Part Number: CY7C64714-128AXC
• Description: IC MCU USB EZ FX1 16KB 128LQFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB FX1™r

Specifications of CY7C64714-128AXC

• Applications: USB Microcontroller
• Core Processor: 8051
• Program Memory Type: ROMless
• Controller Series: CY7C647xx
• Ram Size: 16K x 8
• Interface: I²C, USB, USART
• Number Of I /o: 40
• Voltage - Supply: 3.15 V ~ 3.45 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Package Diagrams
13.0
Package Design Notes
Electrical contact of the part to the Printed Circuit Board (PCB)
is made by soldering the leads on the bottom surface of the
package to the PCB. Hence, special attention is required to the
heat transfer area below the package to provide a good
thermal bond to the circuit board. A Copper (Cu) fill is to be
designed into the PCB as a thermal pad under the package.
Heat is transferred from the FX1 through the device’s metal
paddle on the bottom side of the package. Heat from here, is
conducted to the PCB at the thermal pad. It is then conducted
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.
Document #: 38-08039 Rev. *C
Quad Flat Package No Leads (QFN)
Figure 12-3. 128-Lead Thin Plastic Quad Flatpack (14 x 20 x 1.4 mm) A128
(continued)
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:
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.
Figure 13-1 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.
Figure 13-2 is a plot of the solder mask pattern and Figure 13-
3 displays an X-Ray image of the assembly (darker areas
indicate solder).
CY7C64713/14
51-85101-*B
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