RoHS Code:
*G = Pb in glass (exempt per RoHS 2002/95/EC Annex (5))
*C = Pb in ceramic (exempt per RoHS 2002/95/EC Annex (7))
*H = Pb in high temperature solder (exempt per RoHS 2002/95/EC Annex (7))

Pb-Free Overview:
In December 2002, the European Union Parliament approved the content of two directives to better control the management of waste electronic equipment. The two directives are the Waste from Electrical and Electronic Equipment (WEEE) and the Restriction of Hazardous substances (RoHS). The WEEE addresses the collection and treatment requirements of waste electronic equipment for the member countries. The RoHS sets phase-out dates for the use of lead (Pb) and several other materials contained in electronic products. The RoHS states that the targeted materials shall no longer be contained in the electronic products above certain limits unless there is an exemption provided in the rule.

Caliber Pb-free Program:
The Caliber Pb-free program is implemented in accordance with European Union (EU) Legislation titled "Restriction of the use of certain Hazardous Substances (RoHS)" including banning the use of Pb in electronic assemblies after July 1, 2006.

Caliber Definitions:

• Pb-Free Classification: Component and Assembly Pb content shall be less than 0.1% by weight of the device (in accordance to IPC/EIA J-STD-006) and shall not be intentionally introduced
• Components: Caliber’s definition of components apply to quartz crystal devices
• Assemblies: Caliber’s definition of assemblies apply to oscillator devices (XO, VCXO, TCXO, and OCXO's)

Recommended Solder Composition:
Caliber has qualified the following Pb-free solder composition recommended by the North American Electronics Manufacturing Initiative (NEMI): Sn95.5Ag3.9Cu0.6

Pb-free Part Number Identification:
When applicable, the Caliber specification sheet shall indicate if the device is classified as Pb-free.

Process Compatibility:
The Caliber specification sheet identifies the suggested solder reflow profile(s). All Caliber Pb-free products are backwards compatible to earlier lower temperature reflow profile(s).

Marking and Labeling:
Caliber has a Pb-free labeling method for the packaging of all Pb-free products. The lowest level shipping container shall identify the products as Pb-free.

Caliber Lead Free Plans:

Caliber Electronics Inc. is a Quartz Frequency Control Product supplier offering a full range of frequency devices in standard industry packages and footprints. All manufacturing and assembly is accomplished by ISO9001 certified manufacturing locations and subcontractors. Due to the variety of product and packaging options available various solutions and alternative terminal finish options are required. All finishes selected for Caliber Pb-Free product are 100% Lead-Free and where possible industry standard supplier led solutions.

Specific information about Caliber Pb-Free solutions will be indicated on the relevant product data sheets. In general, there are five standard package groups for which the following solutions are available. Metal Can, Through Hole product will utilize Sn/Cu. Metal Can SMD product will use Sn/Ag/Cu. Ceramic product has always been 100% Pb-Free compliant using Au plated terminations. FR4 type product utilizes Au plated terminations and Plastic Molded devices will be manufactured using 100% Matte Tin.

Full Pb-Free compliance will be indicated by using the industry standard Phase 1, 2, 3 classification as some product will not meet Pb-Free compliance due to technical constraints and critical materials incompatibility. Other parts may be 100% Pb-Free without being able to withstand the full industry standard 260°C reflow temperature requirement.

Pure Sn Concerns:

There have been numerous industry concerns over Sn “whisker” growth on plated terminals, an affect caused by creation of elongated single crystals of pure tin that can grow up to 2 mm in length and up to 3 mm in diameter. These conductive whiskers can grow spontaneously without applied electrical current or even moisture, and they are independent of atmospheric pressure (they can grow in a vacuum). Their appearance can be straight or curved, and the outer surface is usually striated. They can start appearing shortly after plating or take years to appear. While no widely accepted single factor explains the exact mechanism, it’s primarily been attributed to stresses in the tin plating itself. That can be due to the actual plating process, formation of intermetallic compounds (within the tin grain boundaries), bending or stretching of plated surface, or scratches in the plating from handling or equipment.

The newer plating processes and equipment used by our suppliers has significantly reduced or eliminated the risk of Sn whisker growth on package terminals. Our assembly suppliers have all performed extensive tests and monitors, trying to determine if Sn whisker growth could be created. None have been found so far, and they continue to monitor their process to insure they will not occur. A remaining concern might be that there is still no industry-accepted test method for determining how Sn whiskers grow on a plated surface. It’s our belief that the current matte Sn plating material and process being used is more than sufficient to avoid the potential risk of Sn whisker growth on IC package terminals. However, in order to assure that fact Caliber has also implemented a post-Sn plating one-hour bake at 150°C with each of our suppliers. Based on a number of industry studies it’s believed that will relieve any stress that could cause whisker growth. Another possible solution now gaining favor is use of nickel underplate; that process is still being considered as an alternative.

Soldering Concerns of Pb Free Plating:

In making these changes to Pb-free solder plating materials, 100% matte Sn, Sn/Bi, and Sn3Ag.05Cu materials will all require higher board mount reflow solder peak temperatures for our customers. Current Sn/Pb solder plating and epoxy mold compounds can withstand a 240 °C peak temperature and still meet Moisture Sensitivity Level (MSL) 1 on all our gull-wing and J-bend leaded packages (MSL3 on BGA and QFP). The new plating materials will require up to 260 °C for proper soldering on boards. Although the IPC/JEDEC J-STD-020B specification (Moisture/Reflow Sensitivity Classification for Non-hermetic Solid State Surface Mount Devices) only requires 250 °C max for Pb-free products. For the epoxy package to withstand the higher temperatures, it will be necessary in many cases to change the mold compound used, especially for thinner types such as TSSOP. If a mold compound should need to be changed, we’ll also want it to meet “green” requirements with material that uses no Sb and Br flame-retardants. This will be done whenever practicable.