83PR226I-01 Datasheet, PDF (12/22 Pages) Integrated Device Technology – Programmable FemtoClock LVPECL Oscillator Replacement

83PR226I-01 Datasheet
VFQFN EPAD Thermal Release Path
In order to maximize both the removal of heat from the package and the electrical performance, a land pattern must be incorporated on
the Printed Circuit Board (PCB) within the footprint of the package corresponding to the exposed metal pad or exposed heat slug on the
package, as shown in Figure 3. The solderable area on the PCB, as defined by the solder mask, should be at least the same size/shape
as the exposed pad/slug area on the package to maximize the thermal/electrical performance. Sufficient clearance should be designed
on the PCB between the outer edges of the land pattern and the inner edges of pad pattern for the leads to avoid any shorts.
While the land pattern on the PCB provides a means of heat transfer and electrical grounding from the package to the board through a
solder joint, thermal vias are necessary to effectively conduct from the surface of the PCB to the ground plane(s). The land pattern must
be connected to ground through these vias. The vias act as “heat pipes”. The number of vias (i.e. “heat pipes”) are application specific
and dependent upon the package power dissipation as well as electrical conductivity requirements. Thus, thermal and electrical analysis
and/or testing are recommended to determine the minimum number needed. Maximum thermal and electrical performance is achieved
when an array of vias is incorporated in the land pattern. It is recommended to use as many vias connected to ground as possible. It is
also recommended that the via diameter should be 12 to 13mils (0.30 to 0.33mm) with 1oz copper via barrel plating. This is desirable to
avoid any solder wicking inside the via during the soldering process which may result in voids in solder between the exposed pad/slug
and the thermal land. Precautions should be taken to eliminate any solder voids between the exposed heat slug and the land pattern.
Note: These recommendations are to be used as a guideline only. For further information, please refer to the Application Note on the
Surface Mount Assembly of Amkor’s Thermally/ Electrically Enhance Leadframe Base Package, Amkor Technology.
PIN
SOLDER
EXPOSED HEAT SLUG
SOLDER
PIN
PIN PAD
GROUND PLANE
THERMAL VIA
LAND PATTERN
(GROUND PAD)
PIN PAD
Figure 3. P.C. Assembly for Exposed Pad Thermal Release Path – Side View (drawing not to scale)
©2017 Integrated Device Technology, Inc.
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April 13, 2017