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Motorola Sensor Device Data
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Mounting and Handling Suggestions
Custom Port Adaptor Installation Techniques
The Motorola MPX silicon pressure sensor is available in a
basic chip carrier cell which is adaptable for attachment
to customer specific housings/ports (Case 344 for 4-pin
devices and Case 867 for 6-pin devices). The basic cell has
chamfered shoulders on both sides which will accept an O-
ring
such
as
Parker
(p/n#2-015-S-469-40). Refer to Figure 1 for the recommended
O-ring to sensor cell interface dimensions.
The sensor cell may also be glued directly to a custom
housing or port using many commercial grade epoxies or RTV
adhesives which adhere to grade Valox 420, reinforced
polyester resin plastic polysulfone (MPX2040D only). The
epoxy should be dispensed in a continuous bead around the
cell-to-port interface shoulder. Refer to Figure 2. Care must be
taken to avoid gaps or voids in the adhesive bead to help
ensure that a complete seal is made when the cell is joined to
the port. After cure, a simple test for gross leaks should be
performed to ensure the integrity of the cell to port bond.
Submerging the device in water for 5 seconds with full rated
pressure applied to the port nozzle and checking for air
bubbles will provide a good indication. Be sure device is
thoroughly dried after this test.
Seal’s
silicone
O-ring
Figure 2.
ADHESIVE BEAD
Standard Port Attach Connection
Motorola also offers standard port options designed to
accept readily available silicone, vinyl, nylon or polyethylene
tubing for the pressure connection. The inside dimension of
the tubing selected should provide a snug fit over the port
nozzle. Dimensions of the ports may be found in the case
outline drawings. Installation and removal of tubing from the
port nozzle must be parallel to the nozzle to avoid undue stress
which may break the nozzle from the port base. Whether
sensors are used with Motorola’s standard ports or customer
specific housings, care must be taken to ensure that force is
uniformly distributed to the package or offset errors may be
induced.
Electrical Connection
The MPX series pressure sensor is designed to be installed
on a printed circuit board (standard 0.100
″
lead spacing) or to
accept an appropriate connector if installed on a baseplate.
The leads of the sensor may be formed at right angles for
assembly to the circuit board, but one must ensure that proper
leadform techniques and tools are employed. Hand or
“needlenose” pliers should never be used for leadforming
unless they are specifically designed for that purpose.
Industrial leadform tooling is available from various compan-
ies including Janesville Tool & Manufacturing(608-868-4925).
Refer to Figure 3 for the recommended leadform technique. It
is also important that once the leads are formed, they should
not be straightened and reformed without expecting reduced
durability. The recommended connector for off-circuit board
applications may be supplied by JST Corp. (1-800-292-4243)
in Mount Prospect, IL. The part numbers for the housing and
pins are:
4 Pin Housing: SMP-04V-BC
6 Pin Housing: SMP-06V-BC
Pin: SHF-01T-0.8SS
The crimp tool part number is: YC12.
Figure 1.
.114
.047
0
.125
.075
.037R
0
.021
.210
″
CELL
Figure 3. Leadforming
TOP CLAMP AREA
BOTTOMCLAMP AREA
Leads should be securely clamped top
and bottom in the area between the
plastic body and the form being sure
that no stress is being put on plastic
body. The area between dotted lines
represents surfaces to be clamped.
F
Freescale Semiconductor, Inc.
n
.