Brazing is the process of joining two or more materials using a metal alloy with a lower melting point than that of the materials being joined. This is done through a heating process that can vary greatly in temperature, depending upon the materials and alloys involved. Our proprietary furnace profiles and furnace controls differentiate AMETEK from our competition.
For more information refer to “BRAZE PROPERTIES
Copper is commonly used to join a frame to a base (such as in a multi-piece package) and also to join a fiber optic tube to a housing. It is most commonly used to braze materials with very similar CTE due to the temperature at which the operation is performed. Copper (99.99%) has a melting temperature of 1083° C.
Gold/Copper is most commonly used to ground leads/pins to a package, although it can also be used to braze a tube to a housing. It is most commonly used in the form of washer preform. AMETEK performs gold/copper brazing at temperatures above 905°C.
BT (CuSil) braze is another alloy that is available as a brazing option. It can be used to join dissimilar metals, such as a Kovar (ASTM F-15 Alloy) frame to a Molybdenum base. The composition of BT (CuSil) is 72% Silver / 28% Copper and its melting temperature is 780° C.
Soldering is defined as the joining of two or more metallic components through the use of any fusible alloy. AMETEK distinguishes soldering from brazing by the lower temperatures (less than 450°C for soldering) than those used during brazing. Most soldering operations are performed after all plating operations have been completed. In this way, soldering can be used to produce parts which would be difficult or impossible to plate after assembly. There are many soldering alloys used at AMETEK. The most common alloys are described below:
Gold/Germanium solder alloy is used by AMETEK to produce solder joints that will not reflow when the customer performs subsequent operations at elevated temperatures (up to 330°C) such as Gold/Tin soldering of the substrate to the package floor. The composition of the alloy used is 88% Gold / 12% Germanium which is a eutectic alloy and has a melting point of 356°C. This type of solder operation is performed in a controlled atmosphere belt furnace which eliminates the need for solder flux.
Gold/Tin alloy is used for soldering where the amount of braze runout needs to be controlled more closely than is possible with Gold/Germanuim. AMETEK may also use Gold/Tin solder following a Gold/Germanium solder operation. The composition of the alloy used is 80% Gold / 20% Tin which is a eutectic alloy and has a melting point of 280°C. This type of solder operation is performed in a controlled atmosphere belt furnace which eliminates the need for solder flux.
Other solder types used by AMETEK include but are not limited to: Lead/Tin, Tin/Silver, and Lead/Silver. All of these solders require the use of flux. Consult Design Engineering for details.