MA-COM ANI-010

ANI-010
Reflow Soldering Guidelines for RoHS* Compliant
VCOs and Synthesizers
Introduction
This application note describes recommended practices and guidelines for the successful assembly of
M/A-COM VCOs and Synthesizers using automated
solder reflow techniques.
Incorrect handling, storage, reflow and cleaning may
damage the components.
Handling and Storage Precautions
M/A-Com VCOs and Synthesizers are static and moisture sensitive and are packaged accordingly.
Appropriate handling precautions should be observed.
The typical shelf life of these components once removed from the protective reel bag is 168hrs.
Exposure to static electricity or over voltage may cause
defects in the product or degrade it’s reliability.
Components should also be stored in such a way so
Rev. -
as to avoid exposure to corrosive, salty or dusty atmospheres, high humidity, direct sunlight and strong
electric fields.
Solder Pad Layout
Each VCO and Synthesizer data sheet recommends
a solder pad layout based on IPC standards.
Deviation from these recommended layouts can
adversely effect the solder joint strength and integrity.
Component Construction
All M/A-Com VCOs and Synthesizers are designed to
withstand solder reflow conditions, as recommended
in this application note.
The table below details the construction of M/A-Com
VCOs and Synthesizers.
Component Construction
Substrate
Type
Plating Construction
Cover Material
FR-4
Leadless
Electroless Nickel Immersion Gold
ENIG
Brass (nickel plated)
Solder Selection
When selecting solder paste, parameters such as flux
type, particle size and metal content should also be
considered. The solder paste should be carefully selected to suit all of the relevant process parameters
being used.
M/A-Com VCOs and Synthesizers are designed to
work with most recommended reflow profiles for the
SAC305/SAC405 type solders, and are fully compatible
with the standard reflow profiles used for the SN60,
SN62 and SN63 solder pastes, including no-clean
pastes.
Solder Screen Guidelines
A solder screen or stencil is required to screen the
minimum amount of solder paste onto the pads of the
footprint. This amount or thickness will directly affect
the quality of the solder joint.
The optimum thickness is 0.18 mm to 0.25 mm
(0.007 inch to 0.010 inch).
Silk screen techniques can control paste thickness
well enough to keep it in the optimum range; the
thickness being a function of the screen mesh, emulsion thickness and printer set up parameters.
A stencil technique can also achieve similar results
by using a stencil made of 0.2 mm (0.008 inch) thick
brass or stainless steel.
The stencil or screen opening should be the same
size as the pads on the footprint (1:1 registration),
excluding any solder resist mask areas.
Component Placement
M/A-Com VCOs and Synthesizers are designed for
placement using automatic Pick and Place equipment.
Component placement is critical to negate shorts
caused by solder bridging.
* Restrictions on Hazardous Substances, European Union Directive 2002/95/EC.
1
Visit www.macomtech.com for additional data sheets and product information.
M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make
changes to the product(s) or information contained herein without notice.
• North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400
• India Tel: +91.80.43537383
• China Tel: +86.21.2407.1588
ANI-010
Reflow Soldering Guidelines for RoHS* Compliant
VCOs and Synthesizers
Rev. -
General Soldering Precautions: Lead-Free Soldering Process
Relation of qualification profile and actual production profile
The profiles listed in this document are not
production reflow profiles, but are related to those
profiles with an added margin of safety to account
for oven variation, temperature drift, and product
variation and process robustness.
Process Requirements
To minimize the thermal stress to which these componets are subjected. Always preheat the printed circuit
board (failure to do so can cause excessive thermal shock
and stress that can result in damage to the component).
The actual profile used in production will be dictated
primarily by the solder composition selected.
We recommended 90 seconds above 217°C with a
maximum temperature not to exceed 260°C.
The ovens used should be 100% convection reflow.
Condition
Exposure
Average ramp-up rate (30°C to 217°C)
> 100°C
> 150°C
> 217°C
Peak Temperature
Cool-down rate (Peak to 50°C)
Time from 30°C to 255°C
less than 3°C / second
between 360-600 seconds
at least 240 seconds
at least 90 seconds
255°C at least 15 seconds
less than 6°C / second
no greater than 360 seconds
All temperatures shown are +5/-0°C
2
Visit www.macomtech.com for additional data sheets and product information.
M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make
changes to the product(s) or information contained herein without notice.
• North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400
• India Tel: +91.80.43537383
• China Tel: +86.21.2407.1588