Flatpack Installation
"Flush" to PC Board Installation
Mounting flush to the PCB surface, as shown in Figure 1, is a widely used method. The flatpack can be anchored to the board by soldering the formed leads directly to eyelets, plated through holes, or the stripline as in Figure 3. A benefit is that the bends in the leads between the device and the solder points provide some stress relief with temperature variations.
Great caution must be taken when forming the bends in the leads
to prevent breakage or stress on the glass beads. Merrimac
strongly recommends the leads be rigidly clamped away from
the glass bead during this operation. A better approach is
to use a properly designed bending fixture.
For high frequency operation, formed leads usually require the addition of lumped capacitance from the signal leads to ground. The capacitance values required are generally low, typically in the 1-2 pF range and can be added by discrete capacitors or the distributed equivalent at the connecting transmission lines.
Figure 1. Mounting "Flush" to PC Board
Mounting in "Cut Out" of PC Board
This method, illustrated in Figure 2, is recommended for high frequency operation, since this provides the shortest lead between the device and its connecting transmission lines. Capacitive tuning is generally not required for this mounting technique.
For best grounding conditions, all of the ground pins should be soldered to ground and the case should be soldered to the ground plane using low temperature solder, melting point close to 1450C (+2950F) or conductive silver epoxy.
Figure 2. Mounting in "Cut Out" PC Board
Figure 3. Lead Bending Constraints
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