U.S. patent application number 10/905176 was filed with the patent office on 2006-07-06 for methods for testing single-use devices.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to David Gerez.
Application Number | 20060144278 10/905176 |
Document ID | / |
Family ID | 36638899 |
Filed Date | 2006-07-06 |
United States Patent
Application |
20060144278 |
Kind Code |
A1 |
Gerez; David |
July 6, 2006 |
Methods for Testing Single-Use Devices
Abstract
Methods for testing single-use electrical devices (e.g.,
explosive detonators and initiators) are provided to ensure
operating reliability of such devices when used in the field. These
methods facilitate testing of non-destructible components of
single-use electrical devices at operating parameters during
production or anytime before field use.
Inventors: |
Gerez; David; (Houston,
TX) |
Correspondence
Address: |
SCHLUMBERGER RESERVOIR COMPLETIONS
14910 AIRLINE ROAD
ROSHARON
TX
77583
US
|
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
300 Schlumberger Drive
Sugar Land
TX
|
Family ID: |
36638899 |
Appl. No.: |
10/905176 |
Filed: |
December 20, 2004 |
Current U.S.
Class: |
102/202.5 |
Current CPC
Class: |
F42C 21/00 20130101 |
Class at
Publication: |
102/202.5 |
International
Class: |
F42B 3/12 20060101
F42B003/12 |
Claims
1. A method for testing an electrical device having a single-use
component and another component, comprising: testing the device;
and electrically connecting the single-use component to the other
component, wherein the testing is performed before the single-use
component and the other component are electrically connected.
2. The method of claim 1, wherein electrically connecting the
single-use component and the other component comprises mounting the
single-use component to a circuit board having a conductive path
formed between the single-use component and the other
component.
3. The method of claim 1, further comprising: mounting the
single-use component and the other component to a circuit board
before the testing is performed, wherein electrically connecting
the single-use component and the other component comprises
completing a conductive path between the single-use component and
the other component.
4. A method for producing an electrical device having a single-use
component and at least one other component, comprising: providing a
circuit board for receiving the single-use component and the at
least one other component and a conductive path for electrically
connecting the single-use component and the at least one other
component; installing the at least one other component on the
circuit board; installing the single-use component on the circuit
board, wherein the conductive path is incomplete between the
single-use component and the at least one other component; testing
the at least one other component; and completing the conductive
path between the single-use component and the at least one other
component.
5. The method of claim 4, wherein completing the conductive path
between the single-use component and the at least one other
component comprises: applying solder between the between the
single-use component and the at least one other component.
6. The method of claim 4, wherein completing the conductive path
between the single-use component and the at least one other
component comprises: connecting a wire between the single-use
component and the at least one other component.
7. The method of claim 4, wherein completing the conductive path
between the single-use component and the at least one other
component comprises: mounting a resistor between the single-use
component and the at least one other component.
8. The method of claim 4, wherein completing the conductive path
between the single-use component and the at least one other
component comprises: applying a conductive strip between the
single-use component and the at least one other component.
9. The method of claim 4, wherein installing the components on the
circuit board comprises: mounting the single-use component on one
side of the circuit board; and mounting the at least one other
component on the other side of the circuit board.
10. The method of claim 9, wherein completing the conductive path
between the single-use component and the at least one other
component comprises: forming a hole in the circuit board between
the single-use component and the at least one other component; and
filling the hole with a conductive element.
11. The method of claim 10, wherein the conductive element is
solder.
12. The method of claim 10, wherein the conductive element is a
pin.
13. The method of claim 4, wherein the electrical device is an
explosive detonator.
14. The method of claim 13, wherein the single-use component is
selected from a group consisting of an exploding foil initiator, an
exploding bridge wire initiator, a semiconductor bridge initiator,
and a hotwire.
15. The method of claim 13, wherein the at least one other
component is selected from a group consisting of a filter, an
addressable chip, a capacitor, a resistor, a transformer, a switch,
and a diode.
16. The method of claim 4, wherein the electrical device is an
igniter.
17. The method of claim 16, wherein the single-use component is
selected from a group consisting of an exploding foil initiator, an
exploding bridge wire initiator, a semiconductor bridge initiator,
and a hotwire.
18. The method of claim 16, wherein the at least one other
component is selected from a group consisting of a filter, an
addressable chip, a capacitor, a resistor, a transformer, a switch,
and a diode.
19. A method for producing an electrical device having a single-use
component and a multi-use component, comprising: providing a
circuit board having a conductive pad for receiving the single-use
component, a conductive pad for receiving the multi-use component,
and a conductive path for electrically connecting the conductive
pad of the single-use component and the conductive pad of the
multi-use component; installing the multi-use component on one of
the conductive pads of the circuit board; installing the single-use
component on the other conductive pad of the circuit board, wherein
the conductive path is incomplete between the conductive pads;
testing the multi-use component in a test fixture; and completing
the conductive path between the conductive pads.
20. The method of claim 17, wherein completing the conductive path
between the conductive pads comprises: connecting a wire between
the conductive pads.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to testing of
devices, and more particularly to methods for testing single-use
electrical devices for oilfield operations.
[0003] 2. Background of the Invention
[0004] Testing of single-use devices during or after production and
before field use poses a particular problem. It is difficult to be
certain that such a single-use device will function as intended in
the field, as any definitive operational test would, by definition,
leave the device unusable. For example, electrical components of
explosive devices (e.g., detonators, charges, initiators, and other
explosive-related single-use devices) are destroyed upon
detonation, thus conventional testing techniques are inadequate to
fully test such devices at operating parameters.
[0005] Presently, one approach for testing single-use devices is to
take a limited sample of the completed units under production, and
carry out a destructive test of this sample. Standard statistical
guidelines may then provide the probability that the remaining
devices outside the sample will perform satisfactorily. While
providing testing of the sample devices at operational parameters,
this approach will not account for unique conditions found in the
remaining devices outside the sample, which may cause
malfunctioning or inoperability.
[0006] Another approach for testing single-use devices is to test
the components of a single-use device as thoroughly as possible but
short of operational levels which may cause destruction. For
example, a capacitor in an electronic circuit of an explosive
detonator may be tested by applying a voltage to the device, but
not one sufficiently high to trigger the detonator. The capacitor
may be charged during operations to 1200-1500V, but only be charged
to 1000V in the production test. Thus, a weakened capacitor that
would fail at 1100V would not be detected, and may result in a
field failure. Therefore, while this type of testing identifies
some faults at sub-operational levels, it does not stress the
system to the same extent as operational use.
[0007] Accordingly, there exists a need for methods to test
single-use devices such that the devices are still operational for
use in the field.
SUMMARY
[0008] The present invention relates to methods for producing and
testing single-use electrical devices to ensure operating
reliability of such devices when used in the field. These methods
facilitate testing of non-destructible components of single-use
electrical devices at operating parameters during production.
[0009] Some embodiments of the present invention include a method
for testing any non-destructive components on an electrical circuit
board at operating parameters during production, yet before any
actual single-use components are installed. In such embodiments,
any single-use components may be installed on the circuit board
after the non-destructive components are tested.
[0010] Other embodiments of the present invention include a method
for testing any non-destructive components on an electrical circuit
board at operating parameters during production and after
single-use components are installed. In such embodiments, the
conductive paths connecting the single-use components to the
non-destructive components are left incomplete until after the
non-destructive components are tested. Once the non-destructive
components are tested at operating parameters, the conductive paths
between the single-use components and the non-destructive
components are completed.
[0011] Other or alternative embodiments of the present invention
will be apparent from the following description, from the drawings,
and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The manner in which these objectives and other desirable
characteristics can be obtained is explained in the following
description and attached drawings in which:
[0013] FIG. 1 illustrates an electrical schematic view of a prior
art EFI initiated detonator, which may be assembled and tested
according to various embodiments of the testing method of the
present invention.
[0014] FIG. 2 illustrates a schematic view of a single-use device
being assembled in accordance with an embodiment of the testing
method of the present invention, where the single-use component is
installed after the non-destructive components are tested.
[0015] FIGS. 3-6 illustrate schematic views of a single-use device
being assembled in accordance with various embodiments of the
testing method of the present invention, where the single-use
component is installed before the non-destructive components are
tested.
[0016] It is to be noted, however, that the appended drawings
illustrate only typical embodiments of this invention and are
therefore not to be considered limiting of its scope, for the
invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0017] In the following description, numerous details are set forth
to provide an understanding of the present invention. However, it
will be understood by those skilled in the art that the present
invention may be practiced without these details and that numerous
variations or modifications from the described embodiments may be
possible.
[0018] In the specification and appended claims: the terms "connect
"connection", "connected", "in connection with", and "connecting"
are used to mean "in direct connection with" or "in connection with
via another element"; and the term "set" is used to mean "one
element" or "more than one element". As used herein, the terms "up"
and "down", "upper" and "lower", "upwardly" and downwardly",
"upstream" and "downstream"; "above" and "below"; and other like
terms indicating relative positions above or below a given point or
element are used in this description to more clearly describe some
embodiments of the invention. Moreover, as used herein, the term
"single-use" describes a device or component of a device that is
designed to only perform a function once under operational
parameters before it is rendered inoperable; and the term
"non-destructive" describes a device or component that is not a
single-use device or component.
[0019] A single-use device may include one or more components in
electrical connection. For example, with respect to FIG. 1
detonator device 10, as described in U.S. patent Ser. No.
10/711,809 and shown in FIG. 1, may include one or more filters,
addressable chips, capacitors, resistors, transformers, switches,
and diodes for the purpose of receiving a voltage to activate an
electrical initiator. The initiator may be an exploding foil
initiator (EFI), an exploding bridge wire (EBW) initiator, a
semiconductor bridge (SCB) initiator, hotwire or another
electrically activated initiator. While some embodiments of this
invention are described for use with testing an initiator component
of a detonator, other embodiments may be used with igniters,
explosive-actuated devices such as exploding bolts, or
propellant-actuated devices such as piston-driven motors, cutters,
valves and other similar devices.
[0020] Generally, it may be desirable to test a single-use device,
like the detonator 10 of FIG. 1, during or after production to
ensure operating reliability when used in the field. According to
one embodiment of the present invention, as shown in FIG. 2, the
single use device 200 may be tested at operating parameters during
production, yet before any actual single-use components are
installed. Once the non-destructive or multi-use components are
tested at operating parameters, the single-use components may be
installed.
[0021] According to another embodiment of the present invention, as
shown in FIGS. 3-6, the single-use device 200 may be tested at
operating parameters during production with all single-use
components installed, yet with an incomplete conductive path
between the single-use components and non-destructive components.
Once the non-destructive components are tested at operating
parameters, the conductive path between the single-use components
and the non-destructive components is completed.
[0022] With more particularity, FIG. 2 illustrates a single-use
device 200 having a circuit board 210, a single-use component 215
(also known as a "one-shot part"), and one or more non-destructive
components 220A, 220B, 220C, 220D. The circuit board 210 may be a
conventional printed-circuit-board (PCB), a flexible PCB, the
substrate of a multi-chip module (MCM), or other circuit board. In
alternative embodiments, the electrical components may be fused
together without the use of a circuit board. Typically,
non-destructive electronic components 220A, 220B, 220C, and 220D
may be assembled onto the PCB 210 by applying a solder paste onto
conductive pads on the PCB and then placing the each component onto
its respective pad. The solder paste prevents shifting of the
components during processing. The PCB 210 is then passed through a
reflow oven (or other conventional solder heating source such as a
wave-solder machine or a manually-operated soldering iron to melt
the solder and establish a mechanical and electrical bond between
the pads of the PCB and the components 220A, 220B, 220C, and 220D.
While this may be a typical technique for connecting electronic
components to a PCB, other conventional techniques (e.g.,
laser-welding or ultrasonic-welding) may also be applied in
achieving the present invention. The process may be repeated for
components mounted on the other side of the PCB 210. Finally, the
board may be tested in an electrical-test fixture designed to apply
electrical stimuli at specified test points and detect the response
of the circuit. This may be a "bed-of-nails" fixture designed to
establish contact with test points on the board, a fixture that
interfaces through the external interfaces of the board (e.g.,
connecting wires), or other similar fixture.
[0023] Still with reference to FIG. 2, in one embodiment of the
present invention, a method is provided for performing an
electrical test of a single-use device 200, before connection of
the single-use component 215 to the PCB 210. In this embodiment,
only after completion of the electrical test is the single-use
component 215 mounted on the board 210. The single-use component
215 may be mounted using one of several possible techniques. First,
the single-use device 215 may be soldered to a conductive pad 212
by applying solder and re-heating the board in the reflow oven.
Second, instead of solder, a conductive epoxy may be used to set
the component 215 to the pad 212 of the PCB 210 at a relatively low
temperature, thus the device 200 would not be subjected to the high
temperatures of a reflow oven. In addition, this technique could be
applied without modifying the existing board design or introducing
the complexity of additional components (as shown in FIGS. 4, 5,
and 6). Third, the component 215 may be soldered to the PCB 210 by
locally heating the conductive pad 212 (e.g., as with a hot iron, a
stream of heated gas, ultrasonic energy, infrared energy, halogen
light, and so forth). Other mechanical techniques for connecting
the single-use component 215 to the pad 12 of the PCB 210 (e.g.,
jumpers and latching) may also be employed, however, because many
single-use devices (e.g. EFI detonators) require a fast-rising
high-current pulse, the resistance and inductance of the circuit
are critical parameters and the use of many mechanical connectors
may be precluded.
[0024] With respect to FIG. 3, another embodiment of the present
invention is provided including a method for testing a single-use
device 200 by delaying the establishment of a conductive path
between the single-use component 215 and the non-destructive
components 220A, 220B, 220C, 220D. Under this method, the
single-use component 215 is soldered to the pad 226 of the PCB 210
using the standard production process; however, a gap 223 in the
conductive path between the pads 225, 226 for the single-use
component 215 and the rest of the circuit (i.e., the
non-destructive components 220A, 220B, 220C, 220D) provides an
electrical isolation such that the circuit is maintained and
testing can be carried out without activating the single-use
component 215. Once the test is complete, a conductive path may be
established in different ways (as shown in FIGS. 4-6).
[0025] FIG. 4 illustrates an embodiment of the technique for
establishing a conductive path whereby the gap 223 between the
single-use component 215 and non-destructive components 220A, 220B,
220C, 220D is bridged by applying solder 230. Alternatively,
soldering wires, low-resistance surface-mount resistors, a
conductive strip or web, conductive epoxy, or other conductive
materials may also be employed to bridge the gap 230. In one
embodiment, a wire is used to bridge the gap 223 between the
conductive pads 225, 226 instead of the solder bead 223 as shown.
The wire may be connected to the conductive pads 225, 226 by
applying a bead of solder to each end of the wire, by gluing or
applying an epoxy to the wire, or by application of another
adhesive material.
[0026] FIG. 5 illustrates another embodiment of the technique for
establishing a conductive path whereby the gap 223 between the
single-use component 215 and non-destructive components 220A, 220B,
220C, 220D is bridged. In this embodiment, the pad 226 for mounting
the single-use component 215 and the pad 225 connecting to the
non-destructive components 220A, 220B, 220C, 220D are on opposite
sides of the PCB 210. The non-conductive gap 223 is maintained by
the thickness of the PCB 210, which itself may be fabricated from
an insulating material (e.g., polyamide, PFTE, ceramic, or
figerglass-reinforced plastic, or other insulating material). The
pads 225, 226 and the PCB 210 may be fabricated with a hole
therethrough for insertion of a conductive bridging element 240 to
connect the component 215 to the non-destructive components 220A,
220B, 220C, 220D after testing is complete. Alternatively, a hole
may be drilled through the pads 225, 226 and the PCB 210 after
production or after testing, as with a laser or mechanical drill.
Once again, after testing is complete, a conductive bridging
element may be employed. The bridging element 240 may be formed by
any number of means including, but not limited to, solder set by a
localized heating process (e.g., a hot iron or stream of hot gas),
electrical connections between layers, such as inter-layer vias,
one or more pins (e.g., rods, bolts, rivets, or other similar
structural connecting element) inserted through the hole in board
210 such that each pad 225, 226 is engaged, a conductive epoxy, and
so forth.
[0027] FIG. 6 illustrates yet another embodiment of the technique
for establishing a conductive path whereby the gap 223 between the
single-use component 215 and non-destructive components 220A, 220B,
220C, 220D is bridged by a moveable flap 250. In this embodiment,
the flap 250 is mounted on the board 210 with a conductive pad 225
on its surface. The flap 250 may be moved by shifting, rotating, or
folding over, to establish a connection with the pad 226 of the
single-use component 215. The flap 250 may be held in place by any
conventional means including, but not limited to, soldering,
conductive epoxy, pins, and so forth.
[0028] Although only a few exemplary embodiments of this invention
have been described in detail above, those skilled in the art will
readily appreciate that many modifications are possible in the
exemplary embodiments without materially departing from the novel
teachings and advantages of this invention. Accordingly, all such
modifications are intended to be included within the scope of this
invention as defined in the following claims. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and not only
structural equivalents, but also equivalent structures. Thus,
although a nail and a screw may not be structural equivalents in
that a nail employs a cylindrical surface to secure wooden parts
together, whereas a screw employs a helical surface, in the
environment of fastening wooden parts, a nail and a screw may be
equivalent structures. It is the express intention of the applicant
not to invoke 35 U.S.C. .sctn.112, paragraph 6 for any limitations
of any of the claims herein, except for those in which the claim
expressly uses the words `means for` together with an associated
function.
* * * * *