A flatpack is a type of package in which the leads are in a
plane which is parallel to the substrate mounting surface. Aegis’
flatpacks range from as narrow as .250” wide up to more than 2” long.
Flatpacks have been made in sizes up to 4” square with over 350 leads.
Flatpacks usually have a wall thickness of .040” or thicker, and are
usually rectangular or square. Flatpacks are grouped into one of three
general categories: One-piece, Multi-piece, or Special.
A one-piece flatpack is a type of flatpack in which the body is
formed from one piece of metal in a process called deep drawing. The
result is a body with no braze joints or seams. The bottom thickness
originally matches the thickness of the walls but may be reduced by
grinding after the body is formed.
A multi-piece flatpack is a type of flatpack in which the ring frame (four walls) is formed by deep drawing. The bottom is separately stamped from flat stock. The ring frame and bottom will be produced from the same type of metal. The bottom and the ring frame are joined together using a brazing process during assembly.
A special flatpack may be either a one-piece or multi-piece flatpack that also includes one or more special characteristics such as:
Extended bottom No bottom
Special connector Fiber optic ports (tubes)
Unusual lead forming Dissimilar material for ring frame & bottom
Flatpack Design Rules
While Aegis prides itself on providing highly customized hermetic packages, there are some design rules that will help ensure timely, economical, and repeatable production of a robust hermetic package.
- Glass seal diameter = (wall thickness x 0.7) + lead width or diameter
- Minimum distance from top edge of glass seal to seal ring >=.050”
- Lead pitch = either .050” or .100”
- Max leads/side =integer[(length of side – (2 x wall thickness) -.040”)/lead pitch]
A plug-in is a type of package in which the leads are perpendicular to the substrate mounting surface. The all-metal plug-in is available as small as .390” wide and a large as nearly 3” long. Plug-ins usually have a wall thickness of .040” or thicker, and are usually rectangular or square.