HMPS-2820 Datasheet, PDF (6/8 Pages) AVAGO TECHNOLOGIES LIMITED – MiniPak Surface Mount RF Schottky Barrier Diodes Single and dual versions

Assembly Information
The MiniPak diode is mounted to the PCB or microstrip
board using the pad pattern shown in ­Figure 17.
0.4
0.5
0.4
0.3
0.5
0.3
Figure 17. PCB Pad Layout, MiniPak (dimensions in mm).
This mounting pad pattern is satisfactory for most ap-
plications. However, there are applications where a high
degree of isolation is required between one diode and
the other is required. For such applications, the mounting
pad pattern of Figure 18 is ­recommended.
0.40 mm via hole
(4 places)
0.20
0.8
2.40
0.40
2.60
SMT Assembly
Reliable assembly of surface mount components is a
complex process that involves many material, process,
and equipment factors, including: method of heating
(e.g., IR or vapor phase reflow, wave soldering, etc.) circuit
board material, conductor thickness and ­pattern, type of
solder alloy, and the thermal conductivity and thermal
mass of components. Components with a low mass, such
as the MiniPak package, will reach solder reflow tempera-
tures faster than those with a greater mass.
After ramping up from room temperature, the ­ circuit
board with components attached to it (held in place with
solder paste) passes through one or more preheat zones.
The preheat zones increase the temperature of the board
and components to prevent thermal shock and begin
evaporating solvents from the solder paste. The reflow
zone briefly elevates the temperature sufficiently to
produce a reflow of the solder.
The rates of change of temperature for the ramp-up
and cool-down zones are chosen to be low enough
to not cause deformation of the board or damage to
­components due to thermal shock. The maximum
­temperature in the reflow zone (T_MAX) should not ­exceed
255°C.
These parameters are typical for a surface mount ­assembly
process for Avago diodes. As a general guideline, the
circuit board and components should be ­ exposed only
to the minimum temperatures and times necessary to
achieve a uniform reflow of solder.
Figure 18. PCB Pad Layout, High Isolation MiniPak (dimensions in mm).
This pattern uses four via holes, connecting the crossed
ground strip pattern to the ground plane of the board.