U.S. patent application number 11/842456 was filed with the patent office on 2009-02-26 for vibration isolators for printed wiring boards.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. Invention is credited to Lori J. Armon, Larren E. Boyd, William P. Platt, James P. Turner.
Application Number | 20090050517 11/842456 |
Document ID | / |
Family ID | 40090228 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090050517 |
Kind Code |
A1 |
Platt; William P. ; et
al. |
February 26, 2009 |
VIBRATION ISOLATORS FOR PRINTED WIRING BOARDS
Abstract
A vibration isolator device for printed wiring boards. An
example vibration isolator device includes a solder tab with an
elastomeric material that is adhesively attached to a first side of
the solder tab. The second side of the solder tab is attached to a
printed wiring board. Solder paste is pre-applied to the printed
wiring board prior to attachment of the vibration isolator device.
The solder tab has a U-shaped cross section.
Inventors: |
Platt; William P.; (Forest
Lake, MN) ; Boyd; Larren E.; (Golden Valley, MN)
; Turner; James P.; (St. Paul, MN) ; Armon; Lori
J.; (Minneapolis, MN) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.;PATENT SERVICES AB-2B
101 COLUMBIA ROAD, P.O. BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morristown
NJ
|
Family ID: |
40090228 |
Appl. No.: |
11/842456 |
Filed: |
August 21, 2007 |
Current U.S.
Class: |
206/706 ;
206/521 |
Current CPC
Class: |
H05K 3/3405 20130101;
H05K 1/0271 20130101; H05K 2201/10386 20130101; H05K 7/1417
20130101; H05K 2201/2045 20130101; H05K 2201/0133 20130101 |
Class at
Publication: |
206/706 ;
206/521 |
International
Class: |
B65D 85/00 20060101
B65D085/00 |
Claims
1. An isolator apparatus comprising: a solder tab; and an
elastomeric material adhesively attached to a first side of the
solder tab, wherein a second side of the solder tab is attached to
a support structure.
2. The apparatus of claim 1, further comprising a solder material
positioned between the solder tab and the support structure.
3. The apparatus of claim 1, wherein the solder tab has a U-shaped
cross section.
4. The apparatus of claim 1, wherein the solder tab is a solderable
material.
5. The apparatus of claim 1, wherein the solder tab and elastomeric
material are extracted from a linear extension of a plurality of
solder tabs with attached elastomeric material.
6. The apparatus of claim 5, wherein the linear extension of a
plurality of solder tabs with attached elastomeric material is
provided on a reel.
7. The apparatus of claim 5, wherein the solder tabs are placed in
desired positions on the support structure using an automated pick
and place machine.
8. The apparatus of claim 1, wherein the support structure is a
printed wiring board.
9. An isolator system comprising: one or more isolator devices
comprising: a solder tab; and an elastomeric material adhesively
attached to a first side of the solder tab; a support structure;
and a package, wherein a second side of each solder tab is attached
to a support structure and the support structure is mounted within
the package such that only the elastomeric material makes contact
with the package.
10. The apparatus of claim 9, wherein the support structure is a
printed wiring board.
11. The system of claim 10, wherein the printed wiring board
comprises a receiving groove located on one side, the groove
configured to receive at least a portion of the elastomeric
material.
12. The system of claim 10, wherein the one or more isolator
devices are positioned on at least one of an edge or side of the
printed wiring board based on center of gravity of the printed
wiring board.
Description
BACKGROUND OF THE INVENTION
[0001] Present vibration acoustic isolators for printed wiring
boards (PWB) are typically too large to fit on small PWB's used
with micro-electro mechanical systems (MEMS) gyros. Typical devices
that are used for isolating PWB's from undesired shocks are used
between a package that includes the PWB's and the device to which
the package is mounted. This method is costly because of the number
of steps for installation. Also, these isolators are large with
respect to small printed wiring boards, thus occupying valuable
space.
SUMMARY OF THE INVENTION
[0002] The present invention provides a vibration isolator device
for printed wiring boards. An example vibration isolator device
includes a solder tab with an elastomeric material that is
adhesively attached to a first side of the solder tab. The second
side of the solder tab is attached to a printed wiring board.
[0003] In one aspect of the present invention, solder paste is
pre-applied to the printed wiring board prior to attachment of the
vibration isolator device.
[0004] In another aspect of the present invention, the solder tab
has a U-shaped cross section.
[0005] In still another aspect of the present invention, a
receiving groove is located on a side of a printed wiring board.
The groove receives at least a portion of the elastomeric
material.
[0006] In yet another aspect of the present invention, the tab is a
solderable material. The solder tab and elastomeric material are
extracted from a linear extension of a plurality of solder tabs
with attached elastomeric material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIGS. 1A and 1B illustrate front and side views of examples
formed in accordance with the embodiment of the present
invention;
[0008] FIG. 2 illustrates a side cross-sectional view of an
alternate embodiment formed in accordance with the present
invention;
[0009] FIGS. 3-5 illustrate perspective views of an example
implementation of the present invention; and
[0010] FIG. 6 illustrates a view of an alternate embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] FIGS. 1A and 1B illustrate side and front views of an
example system 20 for isolating a printed wiring board (PWB) 24
from base and side walls 22a, b of a chassis or package (not
shown). In this example, the PWB 24 is a fibrous or other similar
material board that includes predefined circuit traces and includes
mounts for receiving a number of different electronic components,
such as a micro-electro mechanical system (MEMS) sensor 32.
[0012] The system 20 includes one or more isolators 26 that attach
to the PWB 24 and provide isolation between the PWB 24 and the base
and walls 22 of the package. The isolator 26 includes a solder tab
30 and an elastic isolator 28. The isolators 26 may be formed in an
elongated form supplied in a flexible reel. An operator cuts a
portion of the isolator 26 from the reel for use prior to
attachment to the PWB 24. In one embodiment, the solder tab 30 is
brass or is a metal or other alloy having similar properties to
brass for solderability. The elastic isolator 28 is a silicone
based isolator or is a material having similar properties such as
rubber cement. The elastic isolator 28 is adhesively attached to
one side or a portion of one side of the solder tab 30. The elastic
isolator 28 is attached using an adhesive or is directly attached
to the solder tab 30 because it has adhesive properties.
[0013] The solder tab 30 is sized based on the thickness of the PWB
24 before it is attached to the PWB 24. The solder tab 44 is
preformed into a cross sectional U-shape that is sized to be
received by the PWB 24. Before the isolator 26 is attached to the
PWB 24, a mask is applied to the PWB 24 based on the location where
the solder tab 30 will come in contact with the PWB 24. Then, a
solder paste, for example, lead Pb, tinSn, an oil-based resin or
comparable adhesive material, is applied to the PWB 24 based on the
applied mask. Then, the mask is removed after the application of
the solder paste and the isolator 26 is placed onto the desired
location on the PWB 24 either manually or by a pick and place
automated machine (not shown). If the solder paste requires heat
curing, then after the isolator 26 is attached to the PWB 24 and
possibly after any electronic components are attached to the PWB
24, a heating process (e.g. IR reflow, wave process, or other known
techniques) is applied to all, thereby simultaneously curing the
electronic components and the isolators 26 to the PWB 24.
[0014] FIG. 2 illustrates a cross-sectional view of an isolator 40
that is attached to the PWB 24. The isolator 40 includes an elastic
isolator 42 and a solder tab 44. In this example, a chassis or
package wall or base 46 includes a groove or cavity 48 that is
designed to receive the elastic isolator 42 of the isolator 40. The
groove or cavity 48 can be designed such that the base of the PWB
24 extends below the plans of the surface of the wall 46. The
solder tab 44 is similar to the solder tab 30 of FIGS. 1A, 1B. The
elastic isolator 42 attached thereto is similar to the isolator 28
of FIGS. 1A and 1B, except that the elastic isolator 42 is attached
to 3 outside surfaces of the u-shaped solder tab 44.
[0015] In one embodiment, the solder tab 30 of the isolator 26 is
cut from the flat tape reel with a thickness greater than the
thickness of the PWB 24. When the isolator 26 is to be attached to
the PWB 24, a manual or automatic device bends the solder tab 30
around the edges of the PWB 24 in order to form a cross-sectional
U-shape.
[0016] FIG. 3 illustrates a perspective view of isolator 60 having
a U-shaped cross-sectioned solder tab 64 covered on its outside
surface with an elastic isolator 68.
[0017] FIGS. 4 and 5 illustrate perspective views of a PWB 70
having four isolators 60 attached to an outer edge of the PWB 70. A
package 80 is designed to receive one or more PWB's 70 with the
attached isolators 60. The isolators 60 come in contact with
interior walls of the package 80 in order to provide adequate shock
or vibration protection for the PWB 70. Also, the isolators 60 may
come in contact with isolators 60 on each other for adjacent PWB 70
in order to provide adequate separation between the PWB 70.
[0018] As shown in FIG. 6, an isolator 80 includes a flat solder
tab 82 that attaches to a PWB 88 at a front or back surface of the
PWB 88. An elastomeric material 84 that is attached to one side of
the solder tab 82 protects the PWB 88 from shock from a package
wall 90.
[0019] In the present invention, the isolators can be moved on the
board in relation to the board's center of gravity. This
adjustability allows "tuning" of the board to eliminate vibration
resonance nodes and improve on isolation performance parameters
such as VRE (vibration rectification error).
[0020] While the preferred embodiment of the invention has been
illustrated and described, as noted above, many changes can be made
without departing from the spirit and scope of the invention. For
example, the isolator described above may be for providing
vibration isolation for a variety of support structures other than
printed wiring boards. Accordingly, the scope of the invention is
not limited by the disclosure of the preferred embodiment. Instead,
the invention should be determined entirely by reference to the
claims that follow.
* * * * *