U.S. patent application number 15/661368 was filed with the patent office on 2018-02-01 for plating having increased thickness and reduced grain size.
This patent application is currently assigned to Apple Inc.. The applicant listed for this patent is Apple Inc.. Invention is credited to Hani Esmaeili, Raymund W. M. Kwok, Daniel C. Wagman, James A. Wright.
Application Number | 20180030608 15/661368 |
Document ID | / |
Family ID | 61009330 |
Filed Date | 2018-02-01 |
United States Patent
Application |
20180030608 |
Kind Code |
A1 |
Kwok; Raymund W. M. ; et
al. |
February 1, 2018 |
PLATING HAVING INCREASED THICKNESS AND REDUCED GRAIN SIZE
Abstract
Contacts that may be highly corrosion resistant, less
susceptible to wear, and may be readily manufactured with a process
that controls or reduces resource usage. Corrosion resistance and
wear performance may be improved by providing a thicker plating
that has a reduced tendency to crack and by using materials that
act as catalysts. Wear performance may be improved by reducing
grain size for a harder plating. An amount of resources needed may
be reduced or controlled by using materials that plate well and by
using a manufacturing process having a reduced number of steps.
Inventors: |
Kwok; Raymund W. M.; (Hong
Kong, HK) ; Wright; James A.; (Los Gatos, CA)
; Esmaeili; Hani; (Santa Clara, CA) ; Wagman;
Daniel C.; (Scotts Valley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Assignee: |
Apple Inc.
Cupertino
CA
|
Family ID: |
61009330 |
Appl. No.: |
15/661368 |
Filed: |
July 27, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62367610 |
Jul 27, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 5/18 20130101; C25D
3/567 20130101; C25D 5/34 20130101; C25D 7/00 20130101 |
International
Class: |
C25D 5/18 20060101
C25D005/18; C25D 7/00 20060101 C25D007/00; C25D 3/56 20060101
C25D003/56 |
Claims
1. A method of forming a contact, the method comprising: plating
the contact with a binary alloy by: receiving a contact; applying
an alternating signal to the contact; and at least partially
submerging the contact in a bath, the bath comprising: a first
element in a first group consisting of platinum, palladium,
iridium, osmium, rhodium, and ruthenium; and a second element in a
second group consisting of platinum, palladium, iridium, osmium,
rhodium, and ruthenium, where the second element is different from
the first element.
2. The method of claim 1 wherein the first group consists of
platinum, palladium, iridium, osmium, and rhodium.
3. The method of claim 2 wherein the second group consists of
platinum, palladium, iridium, ruthenium, osmium, and rhodium.
4. The method of claim 1 wherein the first element is rhodium and
the second element is ruthenium.
5. The method of claim 1 further comprising, before plating the
contact with a binary alloy, stamping the contact.
6. The method of claim 5 further comprising, after stamping the
contact and before plating the contact with a binary alloy, plating
at least a portion of the contact with a leveling agent.
7. The method of claim 6 wherein the leveling agent is copper.
8. A method of forming a contact, the method comprising: plating
the contact with a binary alloy by: selecting a first element by
choosing a good catalyst that plates well; selecting a second
element by choosing an inorganic grain refiner that is a good
catalyst, applying an alternating signal to the contact; and at
least partially submerging the contact in a bath comprising the
binary alloy.
9. The method of claim 8 wherein the first element is one of a
group consisting of platinum, palladium, iridium, osmium, and
rhodium.
10. The method of claim 9 wherein the second element is one of a
group consisting of platinum, palladium, iridium, ruthenium,
osmium, and rhodium.
11. The method of claim 8 wherein the first element is rhodium and
the second element is ruthenium.
12. The method of claim 11 wherein the binary alloy is
approximately 99 percent rhodium and approximately 1 percent
ruthenium.
13. The method of claim 12 wherein the binary alloy is
approximately 90 percent rhodium and approximately 10 percent
ruthenium.
14. A method of forming a contact, the method comprising: stamping
a contact; plating at least a first portion of the contact with a
leveling agent; and plating a least a portion of the first portion
of the contact with a binary alloy by: applying a signal to the
contact; and at least partially submerging the contact in a
bath.
15. The method of claim 14 wherein the binary alloy comprises: a
first element in a first group consisting of platinum, palladium,
iridium, osmium, rhodium, and ruthenium; and a second element in a
second group consisting of platinum, palladium, iridium, osmium,
rhodium, and ruthenium, where the second element is different from
the first element.
16. The method of claim 15 wherein the first group consists of
platinum, palladium, iridium, osmium, and rhodium.
17. The method of claim 16 wherein the second group consists of
platinum, palladium, iridium, ruthenium, osmium, and rhodium.
18. The method of claim 17 wherein the first element is rhodium and
the second element is ruthenium.
19. The method of claim 17 wherein the binary alloy is
approximately 90 percent rhodium and approximately 10 percent
ruthenium.
20. The method of claim 14 wherein the leveling agent is copper.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
provisional application No. 62/367,610, filed Jul. 27, 2016, which
is incorporated by reference.
BACKGROUND
[0002] Electronic devices often include one or more connector
receptacles though which they may provide and receive power and
data. This power and data may be conveyed over cables that may
include a connector insert at each end of a cable. The connector
inserts may be inserted into connector receptacles in the
communicating electronic devices.
[0003] The contacts in these various connectors may be exposed to
liquids and fluids that may cause the contacts to corrode. For
example, a user may purposely or inadvertently submerge an
electronic device or a connector insert in a liquid. A user may
spill a liquid or perspire on contacts on an electronic device or
connector insert. This may cause one or more contacts to corrode,
particularly where a voltage is present on the one or more
contacts. This corrosion may impair the operation of the electronic
device or cable and in severe cases may render the device or cable
inoperable. This corrosion may also mar the appearance of the
contacts. Where the contacts are at the surface of an electronic
device or at the surface of a connector insert on a cable, such
corrosion may be readily apparent to a user. Even when such
corrosion does not reach the level of device impairment, it may
create a negative impression in the mind of a user that may reflect
poorly on the device or cable and the device or cable's
manufacturer. This corrosion may be exacerbated by additional wear
on the contacts.
[0004] These connector inserts may be inserted into the connector
receptacles many times over the lifetime of a device. These
repeated insertions may cause wear to occur on contacts on either
or both the connector inserts and connector receptacles. Like
corrosion, this wear may cause either connector to become worn
looking. This wear may also provide a pathway for corrosion.
[0005] Some of these electronic devices may be very popular and may
therefore be manufactured in great numbers. Therefore it may be
desirable that these contacts be readily manufactured such that
demand for the devices may be met. Also, it may be desirable to
control or reduce the amount of resources used during the
manufacturing process.
[0006] Thus, what is needed are contacts that may be highly
corrosion resistant, less susceptible to wear, and may be readily
manufactured with a process that controls or reduces resource
usage.
SUMMARY
[0007] Accordingly, embodiments of the present invention may
provide contacts that may be highly corrosion resistant, less
susceptible to wear, and may be readily manufactured with a process
that controls or reduces resource usage. These contacts may be
located at a surface of an electronic device, at a surface of a
connector insert on a cable, in a connector receptacle on an
electronic device, or elsewhere.
[0008] These and other embodiments of the present invention may
provide contacts that are highly corrosion resistant. These
contacts may be plated with a material that acts as a catalyst in
order to improve corrosion resistance. Specifically, the plating
material may act as a catalyst to reduce water into oxygen, thereby
preventing the plating material from dissolving into the water.
These and other embodiments of the present invention may provide a
plating that acts as a good catalyst by using one or more platinum
group elements. These one or more platinum group elements may be
combined with one or more other elements in various embodiments of
the present invention.
[0009] These and other embodiments of the present invention may
further improve corrosion resistance by providing a plating layer
for contacts where the plating layer has reduced localized stress.
This reduced stress may result in a reduced tendency to crack. This
reduction in cracking may prevent moisture from seeping through
cracks in the plating layer and reaching an underlying layer, which
may be more susceptible to corrosion. These and other embodiments
of the present invention may provide a plating for a contact where
the plating is performed using an alternating or pulsed signal,
such as a voltage or current. This alternating or pulsed voltage or
current may provide a plating that has reduced local stresses.
Further, the use of this pulsed plating may help to reduce grain
size of the material being plated. Grain size may further be
reduced by using a grain refiner. The use of pulsed plating and a
grain refiner may aid in reducing local stresses.
[0010] These and other embodiments of the present invention may
further improve corrosion resistance by providing a plating layer
having an increased thickness. This increased thickness may provide
more material to be dissolved by moisture or removed by wear before
more vulnerable underlying layers of the contact may be reached.
This increased thickness may also reduce the chances that a crack
in the plating layer may reach from a surface of the contact to the
vulnerable underlying layers. These and other embodiments of the
present invention may use pulsed plating and a grain refiner to
provide good leveling and small grains such that thicker plating
may be achieved.
[0011] These and other embodiments of the present invention may
provide contacts that are less susceptible to wear. Again, these
contacts may be plated with a layer having an increased thickness.
This increased thickness may provide more material to wear away
before such wear either becomes noticeable or becomes a possible
corrosion problem.
[0012] These and other embodiments of the present invention may
further improve wear by providing a plating layer having a reduced
grain size. This reduced grain size may increase a hardness of the
plating layer, thereby reducing its tendency to wear. In various
embodiments of the present invention grain size may be reduced by
using a material that reduces an energy at the grain boundaries of
the plating material.
[0013] These and other embodiments of the present invention may
provide contacts that may be readily manufactured with a process
that controls or reduces resource usage. For example, embodiments
of the present invention may provide plating layers for contacts
where the materials are chosen for their ability to plate well.
This ability may simplify manufacturing and improve yields. These
embodiments of the present invention may provide a plating stack
for contacts that has a reduced number of steps. This
simplification to the manufacturing process may help to control or
reduce the usage of resources, such as precious metals.
[0014] Again, these and other embodiments of the present invention
may provide a plating for a contact where the plating is performed
using an alternating or pulsed voltage or current. The use of this
pulsed plating may help to reduce grain size of the material being
plated. This reduction in stress and reduced grain size may allow a
thicker plating to be achieved for better corrosion resistance and
for better wear performance. The alternating voltage or current may
also help to provide a more level surface for the resulting
plating. This more level surface may further help to improve the
wear performance of the resulting contact. In these and other
embodiments of the present invention, plating may be done using a
constant or DC voltage or current, or other types of varying
voltage or currents may be used.
[0015] These and other embodiments of the present invention may
provide a method of plating a contact. A substrate for the contact
may be formed of copper or other material. The substrate may be
stamped or otherwise formed. A first plating may be applied to the
substrate to smooth surface defects caused by the stamping process.
This first plating may be copper or other material that may be used
as a leveling agent. A second plating may be applied over the first
plating. Either or both of the first plating and the second plating
may be done using an alternating voltage or current, a constant or
DC voltage or current, or other type of voltage or current
waveform. This process may include a limited number of plating and
other manufacturing process steps. This limited number of plating
layers may reduce a risk of adhesion issues between layers. The
limited number of manufacturing process steps may reduce or control
resource usage and provide an effective way to provide contacts
having good corrosion and wear performance.
[0016] In these and other embodiments of the present invention, the
second plating may be formed using a binary alloy. The binary alloy
may include a first element that is selected for its ability to
plate onto a contact. This ability to plate may help to simplify
the manufacturing process and help to reduce or control an amount
of resources, such as precious metals, consumed. The first element
may further be selected to provide a good catalyst such that water
on a contact is converted into oxygen. This may help to prevent the
plated material from dissolving in the presence of moisture,
particularly when a contact is providing a voltage.
[0017] In these and other embodiments of the present invention, a
second element in the binary alloy may be selected based on its
ability to act as a grain refiner. Specifically, the second element
may be selected for its ability to reduce interfacial energy at the
grain boundaries of the binary alloy as it is plated on a contact
for the purpose of stabilizing a fine grain size and avoiding grain
growth. This smaller grain size may allow binary alloy to be more
thickly plated. The resulting plating may also reduce local stress
in the plating, which may reduce cracking and thereby improve
corrosion resistance. The smaller grain size may further increase
hardness, which may improve wear resistance.
[0018] In these and other embodiments of the present invention, the
second element in the binary alloy may further be selected based on
its ability to be plate well. This ability to plate well may
simplify the manufacturing process and may help to reduce or
control an amount of resources that are consumed. The second
element may also be selected based on its ability to act as a
catalyst to reduce water to oxygen.
[0019] In these and other embodiments of the present invention, the
first element may be an element in a first group consisting of
platinum, palladium, iridium, osmium, rhodium, and ruthenium. In
these and other embodiments of the present invention, the first
element may be an element in a first group consisting of platinum,
palladium, iridium, osmium, and rhodium. In these and other
embodiments of the present invention, the first element may be an
element in a first group consisting of rhodium, iridium, platinum,
and rhenium. In these and other embodiments of the present
invention, the first element may be rhodium.
[0020] In these and other embodiments of the present invention, the
second element may be an element in a second group consisting of
platinum, palladium, iridium, osmium, rhodium, and ruthenium. In
these and other embodiments of the present invention, the second
element may be an element in a second group consisting of platinum,
palladium, iridium, ruthenium, osmium, and rhodium. In these and
other embodiments of the present invention, the second element may
be an element in a second group consisting of molybdenum, niobium,
tungsten, rhenium, iridium, iron, nickel, rhodium, and ruthenium.
In these and other embodiments of the present invention, the second
element may be iridium. In these and other embodiments of the
present invention, the second element may be ruthenium.
[0021] In these and other embodiments of the present invention, the
first element may be rhodium and the second element may be iridium.
In these and other embodiments of the present invention, the first
element may be rhodium and the second element may be one of
molybdenum, niobium, and tungsten. In these and other embodiments
of the present invention, the first element may be iridium and the
second element may be one of rhenium and tungsten. In these and
other embodiments of the present invention, the first element may
be platinum and the second element may be one of iridium, iron,
nickel, rhenium, rhodium, ruthenium, and tungsten.
[0022] In these and other embodiments of the present invention, the
first element may be rhenium and the second element may be
tungsten.
[0023] The use of one of these materials as the second element may
provide an inorganic grain refiner. The use of an inorganic grain
refiner may reduce the amount of hydrogen in the plating, which may
further reduce the tendency of the plating to crack.
[0024] In these and other embodiments of the present invention, the
first element may comprise approximately 90 percent of the binary
alloy by weight, while the second element may comprise
approximately 10 percent of the binary alloy. In these and other
embodiments of the present invention, the first element may
comprise approximately 95 percent of the binary alloy while the
second element may comprise approximately 5 percent of the binary
alloy. In these and other embodiments of the present invention, the
first element may comprise approximately 99 percent of the binary
alloy while the second element may comprise approximately 1 percent
of the binary alloy. In these and other embodiments of the present
invention, the first element may be at least approximately 80
percent, 90 percent, 95 percent, in the range of 80-99 percent, or
other percentage by weight. In these and other embodiments of the
present invention, the second element may be at least approximately
20 percent, 10 percent, 5 percent, in the range of 1-20 percent, or
other percentage by weight. In these and other embodiments of the
present invention, the first element may be rhodium and the second
element may be ruthenium. The binary alloy may have a thickness in
the range of 0.5 to 2 microns, from 1 to 4 microns, from 2 to 6
microns, or more than 6 microns. It may have a thickness of 2
microns, 3 microns, 4 microns, 5 microns, or more than 5 microns.
In these and other embodiments of the present invention, the binary
alloy may have a greater thickness, such as 10-50 microns, 50-100
microns, 100-150 microns, or more than 150 microns. For example, it
may have a thickness of 60 microns, 80 microns, 100 microns, 120
microns, 140 microns, or more than 140 microns.
[0025] In these and other embodiments of the present invention, the
first element may comprise more than or approximately 99.5 percent
of the binary alloy while the second element may comprise less than
or approximately 0.5 percent of the binary alloy, where the
percentages are by weight. This may be particularly true where the
first element is rhodium and the second element is iridium. Iridium
may not plate well, and keeping its percentage to a minimum may
reduce some of the complications that may otherwise result.
[0026] These and other embodiments of the present invention may
provide a contact. A substrate for the contact may be formed of
copper or other material. The substrate may be stamped or otherwise
formed. The contact may have a first plating over the substrate to
smooth surface defects caused by the stamping process. This first
plating may be copper or other material that may be used as a
leveling agent. The contact may further have a second plating over
the first plating. Either or both of the first plating and the
second plating layers may be provided using an alternating or
pulsed voltage or current, though in these and other embodiments of
the present invention an alternating or pulsed voltage or current
is not used.
[0027] In these and other embodiments of the present invention,
other layers, such as barrier layers to prevent corrosion of
internal structures may be included. For example, barrier layers,
such as zinc barrier layers, may be used to protect magnets or
other internal structures from corrosion by cladding or plating
layers. Catalyst layers may be used to improve the rate of
deposition for other layers, thereby improving the manufacturing
process. These catalyst layers may be formed of palladium or other
material. Stress separation layers, such as those formed of copper,
may also be included in these and other embodiments of the present
invention, including the above contacts. Other scratch protection,
passivation, and corrosion resistance layers may also be
included.
[0028] While embodiments of the present invention are well-suited
to contacts and their method of manufacturing, these and other
embodiments of the present invention may be used to improve the
corrosion resistance of other structures. For example, electronic
device cases and enclosures, connector housings and shielding,
battery terminals, magnetic elements, measurement and medical
devices, sensors, fasteners, various portions of wearable computing
devices such as clips and bands, bearings, gears, chains, tools, or
portions of any of these, may be covered with a precious-metal
alloy and plating layers as described herein and otherwise provided
for by embodiments of the present invention. The precious-metal
alloy and plating layers for these structures may be formed or
manufactured as described herein and otherwise provided for by
embodiments of the present invention. For example, magnets and
other structures for fasteners, connectors, speakers, receiver
magnets, receiver magnet assemblies, microphones, and other devices
may have their corrosion resistance improved by structures and
methods such as those shown herein and in other embodiments of the
present invention.
[0029] In various embodiments of the present invention, the
components of contacts and their connector assemblies may be formed
in various ways of various materials. For example, contacts and
other conductive portions may be formed by stamping, coining,
metal-injection molding, machining, micro-machining, 3-D printing,
or other manufacturing process. The conductive portions may be
formed of stainless steel, steel, copper, copper-nickel-silicon
alloy, copper titanium, phosphor bronze, palladium, palladium
silver, or other material or combination of materials, as described
herein. They may be plated or coated with nickel, gold, palladium,
or other material, as described herein. The nonconductive portions,
such as the housings and other portions, may be formed using
injection or other molding, 3-D printing, machining, or other
manufacturing process. The nonconductive portions may be formed of
silicon or silicone, Mylar, Mylar tape, rubber, hard rubber,
plastic, nylon, elastomers, liquid-crystal polymers (LCPs),
ceramics, or other nonconductive material or combination of
materials.
[0030] Embodiments of the present invention may provide contacts
that may be located in, or may connect to, various types of
devices, such as portable computing devices, tablet computers,
desktop computers, laptops, all-in-one computers, wearable
computing devices, cell phones, smart phones, media phones, storage
devices, keyboards, covers, cases, portable media players,
navigation systems, monitors, power supplies, adapters, remote
control devices, chargers, and other devices. These contacts may
provide pathways for signals that are compliant with various
standards such as Universal Serial Bus (USB), High-Definition
Multimedia Interface.RTM. (HDMI), Digital Visual Interface (DVI),
Ethernet, DisplayPort, Thunderbolt.TM., Lightning, Joint Test
Action Group (JTAG), test-access-port (TAP), Directed Automated
Random Testing (DART), universal asynchronous receiver/transmitters
(UARTs), clock signals, power signals, and other types of standard,
non-standard, and proprietary interfaces and combinations thereof
that have been developed, are being developed, or will be developed
in the future. In various embodiments of the present invention,
these interconnect paths provided by these contacts may be used to
convey power, ground, signals, test points, and other voltage or
current, current, data, or other information.
[0031] Various embodiments of the present invention may incorporate
one or more of these and the other features described herein. A
better understanding of the nature and advantages of the present
invention may be gained by reference to the following detailed
description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 illustrates an electronic system according to an
embodiment of the present invention;
[0033] FIG. 2 illustrates a contact according to an embodiment of
the present invention;
[0034] FIG. 3 illustrates a method of reducing corrosion according
to an embodiment of the present invention;
[0035] FIG. 4 illustrates a method of improving wear performance
according to an embodiment of the present invention;
[0036] FIG. 5 illustrates a method of controlling or reducing
resource usage according to an embodiment of the present
invention;
[0037] FIG. 6 illustrates a method of manufacturing a contact
according to an embodiment of the present invention;
[0038] FIG. 7 illustrates a method of selecting an element as a
first element in a binary alloy according to an embodiment of the
present invention;
[0039] FIG. 8 illustrates a method of selecting an element as a
second element in a binary alloy according to an embodiment of the
present invention;
[0040] FIG. 9 illustrates a DC waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention;
[0041] FIG. 10 illustrates a pulsed waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention;
[0042] FIG. 11 illustrates a pulsed waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention; and
[0043] FIG. 12 illustrates another pulsed waveform of a current
flowing through a contact during plating according to an embodiment
of the present invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0044] FIG. 1 illustrates an electronic system according to an
embodiment of the present invention. This figure, as with the other
included figures, is shown for illustrative purposes and does not
limit either the possible embodiments of the present invention or
the claims.
[0045] In this example, host device 110 may be connected to
accessory device 120 in order to share data, power, or both.
Specifically, connector receptacle 112 on host device 110 may be
connected to connector receptacle 122 on accessory device 120 via
cable 130. Cable 130 may include connector insert 132 that may be
inserted into connector receptacle 112 on host device 110 and
connector insert 134 that may be inserted into connector receptacle
122 on accessory device 120. In these and other embodiments of the
present invention, contacts of connector receptacle 112 on host
device 110 may be in physical contact and directly and electrically
connected to contacts of connector receptacle 122 on accessory
device 120.
[0046] The contacts in these various connector receptacles 112 and
122 and connector inserts 132 and 134 may be vulnerable to exposure
to liquids or other fluids. This exposure, particularly when there
are voltages present on the exposed contacts, may lead to their
corrosion. This corrosion may mar the contacts and may be readily
apparent to a user. This corrosion may lead to a reduction in
operation of the device and may even render the device inoperable.
Even when such corrosion does not reach the level of device
impairment, it may create a negative impression in the mind of a
user that may reflect poorly on the device and the device's
manufacturer. Also, the connector inserts 132 and 134 may be
inserted into connector receptacles 112 and 122 many times. This
repeated insert may lead to wear of the various contacts.
[0047] Accordingly, these and other embodiments of the present
invention may provide contacts for connector assemblies that may be
highly corrosion resistant and have improved wear performance. But
ordinarily such an increase in corrosion resistance may lead to a
reduction in manufacturability and an increase in resource usage.
Accordingly, these and other embodiments of the present invention
may provide contacts that are readily manufactured and may be
manufactured with a process that controls or reduces resource
usage. An example of one such contact is shown in the following
figure.
[0048] FIG. 2 illustrates a contact according to an embodiment of
the present invention. This or similar contacts may be used in a
connector insert, such as connector insert 132 and 134, or
connector receptacles, such as connector receptacles 112 and 122 in
FIG. 1. Contact 200 may include beam portion 210 between contacting
portion 220 and surface-mount contacting portion 230. Contacting
portion 220 may mate with a contact in a corresponding connector
when the connector having contact 200 is mated with the
corresponding connector. Surface-mount contacting portion 230 may
be soldered to a contact on a printed circuit board, flexible
circuit board, or other appropriate substrate in an electronic
device housing the connector having contact 200. A stabilizing
portion 240 may be inserted in a housing forming the connector
having contact 200.
[0049] During manufacturing, one or more contacts 200 may be
attached to a carrier (not shown.). The carrier may be detached
from the contacts 200 at the end of manufacturing, or at another
time during manufacturing. The carrier may be attached to
surface-mount contacting portion 230 or other portion of contact
200.
[0050] Contacting portion 220 may include a surface 250. Surface
250 may be exposed to moisture such as sweat, water or other
fluids. These fluids may cause corrosion of contact 200. This
corrosion may be particularly exacerbated by the presence of a
voltage on contact 200. Surface 250 may also engage a corresponding
surface in a corresponding connector. This may lead to wear of
surface 250 of contact 200. Further, contacts 200 may be
manufactured in very high numbers. Accordingly, these and other
embodiments of the present invention may provide contacts 200 that
are corrosion resistant, have good wear performance, and may be
readily manufactured with a process that controls or reduces
resource usage. Examples of methods of providing corrosion
resistance, good wear performance, and controlling or reducing
resource usage are shown in the following figures.
[0051] FIG. 3 illustrates a method of improving corrosion
resistance according to an embodiment of the present invention.
Embodiments of the present invention may provide contacts that may
be plated with a material that acts as a catalyst in order to
improve corrosion resistance. Specifically, in act 310, the plating
material may operate as a catalyst to reduce water into oxygen,
thereby preventing the plating material from dissolving into the
water. Embodiments of the present invention may provide a plating
that acts as a good catalyst by using one or more platinum group
elements. These one or more platinum group elements may be combined
with one or more other elements in various embodiments of the
present invention.
[0052] In act 320, these and other embodiments of the present
invention may further improve corrosion resistance by providing a
plating layer for contacts where the plating layer has reduced
localized stress. This reduced stress may result in a reduced
tendency to crack. This reduction in cracking may prevent moisture
from seeping through cracks in the plating layer and reaching an
underlying layer, which may be more susceptible to corrosion. These
and other embodiments of the present invention may provide a
plating for a contact where the plating is performed using an
alternating or pulsed signal, such as a voltage or current. This
alternating or pulsed voltage or current may provide a plating that
has reduced local stresses. Further, the use of this pulsed plating
may help to reduce grain size of the material being plated. Grain
size may further be reduced by using a grain refiner. The use of
pulsed plating and a grain refiner may aid in reducing local
stresses.
[0053] In act 330, these and other embodiments of the present
invention may further improve corrosion resistance by providing a
plating layer having an increased thickness. This increased
thickness may provide more material to be dissolved by moisture or
removed by wear before more vulnerable underlying layers of the
contact may be reached. This increased thickness may also reduce
the chances that a crack in the plating layer may reach from a
surface of the contact to the vulnerable underlying layers. These
and other embodiments of the present invention may use pulsed
plating and a grain refiner to provide good leveling and small
grains such that a thicker plating may be achieved.
[0054] FIG. 4 illustrates a method of improving wear performance
according to an embodiment of the present invention. Again, in act
410, these contacts may be plated with a layer having an increased
thickness. This increased thickness may provide more material to
wear away before such wear either becomes noticeable or becomes a
possible corrosion problem. In act 420, wear may be further
improved by providing a plating layer having a reduced grain size.
This reduced grain size may increase a hardness of the plating
layer, thereby reducing its tendency to wear. In various
embodiments of the present invention, grain size may be reduced by
employing an inorganic grain refiner. This grain refiner may reduce
the energy at grain boundaries of the plating material, making them
less likely to attract additional atoms and grow in size.
[0055] FIG. 5 illustrates a method of controlling or reducing
resource usage according to an embodiment of the present invention.
In act 510, materials for contact plating layers may be chosen for
their ability to plate well. This may simplify the manufacturing
process and help to improve yields. In act 520, these and other
embodiments of the present invention may provide a plating stack
for contacts that has a reduced number of steps. This
simplification to the manufacturing process may help to reduce or
control an amount of resources, such as precious metals, consumed.
An example of one such manufacturing process is shown in the
following figure.
[0056] FIG. 6 illustrates a method of manufacturing a contact
according to an embodiment of the present invention. A substrate
for the contact may be formed of copper, bronze, copper alloy, or
other material. The substrate may be stamped or otherwise formed,
in act 600. A first plating may be applied to the substrate to
smooth surface defects caused by the stamping process, in act 610.
This first plating may be copper or other material that may be used
as a leveling agent. A second plating may be applied over the first
plating in act 620. The second plating may be done using a binary
alloy. Either or both of the first plating and the second plating
may be done using an alternating voltage or current. For example,
the second step may be performed by applying an alternating or
other voltage or current to a contact. The contact may be at least
partially submerged in a bath comprising the binary alloy. This
process may include a limited number of plating and other
manufacturing process steps. This limited number of plating layers
may reduce a risk of adhesion issues between layers. The limited
number of manufacturing process steps may reduce or control
resource usage and provide an effective way to provide contacts
having good corrosion and wear performance. Methods of selecting
elements for a binary alloy and examples are shown below and in the
following figures.
[0057] FIG. 7 illustrates a method of selecting an element as a
first element in a binary alloy according to an embodiment of the
present invention. The binary alloy may include a first element
that is selected for its ability to plate onto a contact, in act
710. This ability to plate may help to simplify the manufacturing
process and help to reduce or control an amount of resources used
during the manufacturing process. The first element may further be
selected to provide a good catalyst such that water on a contact is
converted into oxygen, in act 720. This may help to prevent the
plated material from dissolving in the presence of moisture,
particularly when a contact is providing a voltage.
[0058] FIG. 8 illustrates a method of selecting an element as a
second element in a binary alloy according to an embodiment of the
present invention. A second element in the binary alloy may be
selected based on its ability to act as a grain refiner in act 810.
Specifically, the second element may be selected for its ability to
reduce an energy at the grain boundaries of the binary alloy as it
is plated on a contact. This smaller grain size may allow binary
alloy to be plated thicker. The resulting plating may also reduce
local stress in the plating, which may reduce cracking and thereby
improve corrosion resistance. The smaller grain size may further
increase hardness, which may improve wear and corrosion
resistance.
[0059] In these and other embodiments of the present invention, the
second element in the binary alloy may further be selected based on
its ability to be plate well, in act 820. This ability to plate
well may simplify the manufacturing process and may help to reduce
or control an amount of resources used. In act 830, the second
element may also be selected based on its ability to act as a
catalyst to reduce water to oxygen.
[0060] In these and other embodiments of the present invention, the
first element may be an element in a first group consisting of
platinum, palladium, iridium, osmium, rhodium, and ruthenium. In
these and other embodiments of the present invention, the first
element may be an element in a first group consisting of platinum,
palladium, iridium, osmium, and rhodium. In these and other
embodiments of the present invention, the first element may be an
element in a first group consisting of rhodium, iridium, platinum,
and rhenium. In these and other embodiments of the present
invention, the first element may be rhodium.
[0061] In these and other embodiments of the present invention, the
second element may be an element in a second group consisting of
platinum, palladium, iridium, osmium, rhodium, and ruthenium. In
these and other embodiments of the present invention, the second
element may be an element in a second group consisting of platinum,
palladium, iridium, ruthenium, osmium, and rhodium. In these and
other embodiments of the present invention, the second element may
be an element in a second group consisting of molybdenum, niobium,
tungsten, rhenium, iridium, iron, nickel, rhodium, and ruthenium.
In these and other embodiments of the present invention, the second
element may be iridium. In these and other embodiments of the
present invention, the second element may be ruthenium.
[0062] In these and other embodiments of the present invention, the
first element may be rhodium and the second element may be iridium.
In these and other embodiments of the present invention, the first
element may be rhodium and the second element may be one of
molybdenum, niobium, and tungsten. In these and other embodiments
of the present invention, the first element may be iridium and the
second element may be one of rhenium and tungsten. In these and
other embodiments of the present invention, the first element may
be platinum and the second element may be one of iridium, iron,
nickel, rhenium, rhodium, ruthenium, and tungsten. In these and
other embodiments of the present invention, the first element may
be rhenium and the second element may be tungsten.
[0063] The use of one of these materials as the second element may
provide an inorganic grain refiner. The use of an inorganic grain
refiner may reduce the amount of hydrogen in the plating, which may
further reduce the tendency of the plating to crack.
[0064] In these and other embodiments of the present invention, the
first element may comprise approximately 90 percent of the binary
alloy while the second element may comprise approximately 10
percent of the binary alloy. In these and other embodiments of the
present invention, the first element may comprise approximately 95
percent of the binary alloy while the second element may comprise
approximately 5 percent of the binary alloy. In these and other
embodiments of the present invention, the first element may
comprise approximately 99 percent of the binary alloy while the
second element may comprise approximately 1 percent of the binary
alloy. In these and other embodiments of the present invention, the
first element may be at least approximately 80 percent, 90 percent,
95 percent, in the range of 80-99 percent, or other percentage by
weight. In these and other embodiments of the present invention,
the second element may be at least approximately 20 percent, 10
percent, 5 percent, in the range of 1-20 percent, or other
percentage by weight. In these and other embodiments of the present
invention, the first element may be rhodium and the second element
may be ruthenium. The binary alloy may have a thickness in the
range of 0.5 to 2 microns, from 1 to 4 microns, from 2 to 6
microns, or more than 6 microns. It may have a thickness of 2
microns, 3 microns, 4 microns, 5 microns, or more than 5 microns.
In these and other embodiments of the present invention, the binary
alloy may have a greater thickness, such as 10-50 microns, 50-100
microns, 100-150 microns, or more than 150 microns. For example, it
may have a thickness of 60 microns, 80 microns, 100 microns, 120
microns, 140 microns, or more than 140 microns.
[0065] In these and other embodiments of the present invention, the
first element may comprise more than or approximately 99.5 percent
of the binary alloy while the second element may comprise less than
or approximately 0.5 percent of the binary alloy. This may be
particularly true where the first element is rhodium and the second
element is iridium. Iridium may not plate well, and keeping its
percentage to a minimum may reduce some of the complications that
may otherwise result.
[0066] In these and other embodiments of the present invention,
including the above contacts, other layers, such as barrier layers
to prevent corrosion of internal structures may be included. For
example, barrier layers, such as zinc barrier layers, may be used
to protect magnets or other internal structures from corrosion by
cladding or plating layers. Catalyst layers may be used to improve
the rate of deposition for other layers, thereby improving the
manufacturing process. These catalyst layers may be formed of
palladium or other material. Stress separation layers, such as
those formed of copper, may also be included in these and other
embodiments of the present invention, including the above contacts.
Other scratch protection, passivation, and corrosion resistance
layers may also be included.
[0067] For example, in FIG. 2, a substrate for contact 200 may be
formed of copper, bronze, copper alloy or other material.
Surface-mount contacting portion 230 of contact 200 may be plated
with a layer of nickel and a gold flash. This may provide a good
layer for soldering the surface-mount contacting portion 230 to a
contact on a printed circuit board, flexible circuit board, or
other appropriate substrate. It may simplify manufacturing to allow
the nickel and gold layers to cover the entire contact. In this
case, a copper leveling layer may be used as a leveling agent and
the copper layer may then be covered with the nickel and gold
layers. A binary alloy may be plated over the nickel and gold
afterward. The gold may assist in the adhesion of the binary alloy.
In these and other embodiments of the present invention, the copper
leveling layer over the contact may have a thickness of 2 microns,
3 microns, 4 microns, 5 microns, or more than 5 microns. In these
and other embodiments of the present invention, the binary alloy
may have a greater thickness, such as 10-50 microns, 50-100
microns, 40-120 u, 100-150 microns, or more than 150 microns. For
example, it may have a thickness of 60 microns, 80 microns, 100
microns, 120 microns, 140 microns, or more than 140 microns. The
nickel layer may be formed of nickel or a nickel alloy, such as an
electroless nickel plating, nickel tungsten, or other material. The
gold flash may have a thickness of 1 micron, 2 microns, 2.2
microns, 2.4 microns, 2.6 microns, 2.8 microns, 3 micron, 4
microns, 5 microns, or more than 5 microns. A binary alloy layer
may then be plated over the contact. In these and other embodiments
of the present invention, one or more of these layers may be
omitted, and one or more other layers may be included.
[0068] Again, in these and other embodiments of the present
invention, plating of one or more layers, such as a binary alloy
layer, may be performed using a signal such as an alternating
voltage or current, though in these and other embodiments of the
present invention, a constant or DC voltage or current may be used.
This binary alloy layer may be plated over the gold flash or other
layer in the example above. Some examples are shown in the
following figures.
[0069] FIG. 9 illustrates a DC waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention. In this example, a constant or DC current having
an amplitude 910 may flow through a contact submerged in a bath for
a duration 920.
[0070] In these and other embodiments of the present invention, the
DC current may have various amplitudes 910. For example, the DC
current may have an amplitude 910 of 1 amps/square decimeter,
(ASD), between 1-5 ASD, 4 ASD, between 4-8 ASD, 4 ASD, 6 ASD, 8
ASD, 10 ASD, 12 ASD, between 5-8 ASD, between 6-12 ASD, 14 ASD,
between 10-20 ASD, 16 ASD, 20 ASD, between 20-30 ASD, 25 ASD, 30
ASD, 35 ASD, between 30-40 ASD, 40 ASD, 45 ASD, 50 ASD, between
40-60 ASD, or more than 60 ASD, or it may have another
amplitude.
[0071] Using a DC waveform as shown may result in an uneven
distribution of the plating material. In these and other
embodiments of the present invention, plating on portions of a
contact near a carrier used during manufacturing may be undesirably
thin, while plating on portions of the contact away from the
carrier may be excessively thick and subject to cracking. (Again, a
contact, such as contact 200 in FIG. 2, may be attached to a
carrier at or near surface-mount contacting portion 230.) This
cracking may result in an increase in the rate of corrosion of the
contact. Similarly, a contact portion having an undesirably thin
plating may not be adequately protected and may also be subject to
corrosion. This uneven distribution of plating may be reduced by
using shielding. This shielding may reduce a localized current flow
current thereby helping to prevent plating in various areas from
becoming excessively thick while other portions remain undesirably
thin.
[0072] Again, in these and other embodiments of the present
invention, an alternating or pulsed signal, such as a voltage or
current, may be applied to, or may flow through, the contact during
plating to improve plating uniformity. Examples are shown in the
following figures.
[0073] FIG. 10 illustrates a pulsed waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention. In this example, an alternating or pulsed
current having amplitude 1010 may flow through a contact submerged
in a bath for a number of pulses. The pulses may be on for a time
1020 and may be off for a time 1030. Off times 1030 may allow time
for ions to migrate to a surface of the contact. This migration may
improve uniformity of the plated material. In these and other
embodiments of the present invention, a shorter on time 1020 and a
longer off time 1030 may improve uniformity of the plated material.
The current density, the amplitude 1010, can be increased to
shorten plating time and increase manufacturing throughput.
[0074] In these and other embodiments of the present invention, on
times 1020 and off times 1030 of the pulses may have various
durations, while the pulses may have various amplitudes 1010. For
example, the pulses may have an amplitude 1010 of 1 ASD, between
1-5 ASD, 4 ASD, between 4-8 ASD, 4 ASD, 6 ASD, 8 ASD, 10 ASD, 12
ASD, between 5-8 ASD, between 6-12 ASD, 14 ASD, between 10-20 ASD,
16 ASD, 20 ASD, between 20-30 ASD, 25 ASD, 30 ASD, 35 ASD, between
30-40 ASD, 40 ASD, 45 ASD, 50 ASD, between 40-60 ASD, or more than
60 ASD, or they may have another amplitude. On time 1020, may have
a duration of 1 milliseconds (ms), 2 ms, between 2-5 ms, 4 ms, 5
ms, 6 ms, between 4-8 ms, 8 ms, 10 ms, between 7-14 ms, 12 ms, 14
ms, 18 ms, between 10-20 ms, 20 ms, 22 ms, 25 ms, between 15-30 ms,
between 20-30 ms, 30 ms, 35 ms, 40 ms, or more than 40 ms. Off time
1030, may have a duration of 1 milliseconds (ms), 2 ms, between 2-5
ms, 4 ms, 5 ms, 6 ms, between 4-8 ms, 8 ms, 10 ms, between 7-14 ms,
12 ms, 14 ms, 18 ms, between 10-20 ms, 20 ms, 22 ms, 25 ms, between
15-30 ms, between 20-30 ms, 30 ms, 35 ms, 40 ms, or more than 40
ms. The on times 1020 and off times 1030 may have the same or
different values.
[0075] FIG. 11 illustrates a pulsed waveform of a current flowing
through a contact during plating according to an embodiment of the
present invention. In this example, forward alternating or pulsing
current having amplitude 1110 may flow through a contact submerged
in a bath for a number of pulses having a duration 1120. These
durations 1120 may be separated by gaps 1130. Gaps 1130 may allow
time for ions to migrate to a surface of the contact. This
migration may improve uniformity in the plated material. Reverse
current pulses having amplitude 1140 may flow during the gaps 1130.
Reverse current pulses having amplitudes 1140 may improve
uniformity and control grain size.
[0076] In these and other embodiments of the present invention,
duration 1120 and gaps 1130 of the pulses may have various
durations, while the forward and reverse pulses may have various
amplitudes 1110 and 1140. For example, the pulses may have
amplitudes 1110 and 1140 of 1 ASD, between 1-5 ASD, 4 ASD, between
4-8 ASD, 4 ASD, 6 ASD, 8 ASD, 10 ASD, 12 ASD, between 5-8 ASD,
between 6-12 ASD, 14 ASD, between 10-20 ASD, 16 ASD, 20 ASD,
between 20-30 ASD, 25 ASD, 30 ASD, 35 ASD, between 30-40 ASD, 40
ASD, 45 ASD, 50 ASD, between 40-60 ASD, or more than 60 ASD, or
they may have another amplitude. Durations 1120 and gaps 1130 may
have a duration of 1 ms, 2 ms, between 2-5 ms, 4 ms, 5 ms, 6 ms,
between 4-8 ms, 8 ms, 10 ms, between 7-14 ms, 12 ms, 14 ms, 18 ms,
between 10-20 ms, 20 ms, 22 ms, 25 ms, between 15-30 ms, between
20-30 ms, 30 ms, 35 ms, 40 ms, or more than 40 ms. Amplitudes 1110
and 1140 may have the same or different values. Durations 1120 and
gaps 1130 may have the same or different durations.
[0077] FIG. 12 illustrates another pulsed waveform of a current
flowing through a contact during plating according to an embodiment
of the present invention. In this example, a pulsing current having
amplitude 1210 may flow through a contact submerged in a bath for a
number of pulses having duration 1220. These pulses may be
separated by gaps 1230 where current does not flow, at least in a
substantial amount. Gaps 1230 may allow time for ions to migrate to
a surface of the contact. This migration may improve uniformity in
the plated material. After current pulses having amplitude 1210
have flowed through the contact, a current pulse having a larger
amplitude 1260 may flow through the contact. The smaller amplitude
pulses having amplitude 1210 may act to primarily plate one of the
elements in the binary alloy, while the larger pulses having
amplitude 1260 may cause the second element in the binary alloy to
plate on the contact. A gap 1250 may follow these larger pulses
having amplitude 1260 and may be longer than gap 1230. Reverse
current pulses having amplitude 1240 may flow during a portion 1270
of the gaps 1250, while current does not flow, at least in a
substantial amount, for the remaining portion 1280 of the gap 1250.
Reverse current pulses having amplitude 1240 may improve uniformity
and control grain size.
[0078] In these and other embodiments of the present invention,
duration 1220 and gaps 1230 and 1250 of the pulses may have various
durations, while the forward and reverse pulses may have various
amplitudes 1210, 1240, and 1260. For example, the pulses may have
amplitudes 1210, 1240, and 1260 of 1 ASD, between 1-5 ASD, 4 ASD,
between 4-8 ASD, 4 ASD, 6 ASD, 8 ASD, 10 ASD, 12 ASD, between 5-8
ASD, between 6-12 ASD, 14 ASD, between 10-20 ASD, 16 ASD, 20 ASD,
between 20-30 ASD, 25 ASD, 30 ASD, 35 ASD, between 30-40 ASD, 40
ASD, 45 ASD, 50 ASD, between 40-60 ASD, or more than 60 ASD, or
they may have another amplitude. Durations 1220 and gaps 1230 and
1250 may have durations of 1 ms, 2 ms, between 2-5 ms, 4 ms, 5 ms,
6 ms, between 4-8 ms, 8 ms, 10 ms, between 7-14 ms, 12 ms, 14 ms,
18 ms, between 10-20 ms, 20 ms, 22 ms, 25 ms, between 15-30 ms,
between 20-30 ms, 30 ms, 35 ms, 40 ms, or more than 40 ms.
Amplitudes 1210, 1240, and 1260 may have the same or different
values. Durations 1220 and gaps 1230 and 1250 may have the same or
different durations.
[0079] In these and other embodiments of the present invention, the
plating may be done by applying a DC or pulsed signal to a contact
while the contact is at least partially submerged in a bath. In
these and other embodiments of the present invention, the contact
may be submerged before a signal is applied to the contact, or a
signal may be applied to the contact before submersion, or these
events may occur simultaneously. In these and other embodiments of
the present invention, these events may occur in either order or
simultaneously.
[0080] A contact 200 has been shown above. In these and other
embodiments of the present invention, other types of contacts may
be made and they may be used in different locations. For example,
they may be located at a surface of a device enclosure, in a
connector insert, in a connector receptacle, or in another
contacting structure. Also, while contact 200 is shown as having a
particular shape, these shapes may vary in these and other
embodiments of the present invention.
[0081] While embodiments of the present invention are well-suited
to contacts and their method of manufacturing, these and other
embodiments of the present invention may be used to improve the
corrosion resistance of other structures. For example, electronic
device cases and enclosures, connector housings and shielding,
battery terminals, magnetic elements, measurement and medical
devices, sensors, fasteners, various portions of wearable computing
devices such as clips and bands, bearings, gears, chains, tools, or
portions of any of these, may be covered with a precious-metal
alloy and plating layers as described herein and otherwise provided
for by embodiments of the present invention. The precious-metal
alloy and plating layers for these structures may be formed or
manufactured as described herein and otherwise provided for by
embodiments of the present invention. For example, magnets and
other structures for fasteners, connectors, speakers, receiver
magnets, receiver magnet assemblies, microphones, and other devices
may have their corrosion resistance improved by structures and
methods such as those shown herein and in other embodiments of the
present invention.
[0082] In these and other embodiments of the present invention, the
components of contacts and their connector assemblies may be formed
in various ways of various materials. For example, contacts and
other conductive portions may be formed by stamping,
metal-injection molding, machining, micro-machining, 3-D printing,
or other manufacturing process. The conductive portions may be
formed of stainless steel, steel, copper, copper-nickel-silicon
alloy, copper titanium, phosphor bronze, palladium, palladium
silver or other material or combination of materials. They may be
plated or coated with nickel, gold, or other material. The
nonconductive portions, such as the housings and other portions may
be formed using injection or other molding, 3-D printing,
machining, or other manufacturing process. The nonconductive
portions may be formed of silicon or silicone, Mylar, Mylar tape,
rubber, hard rubber, plastic, nylon, elastomers, liquid-crystal
polymers (LCPs), ceramics, or other nonconductive material or
combination of materials.
[0083] Embodiments of the present invention may provide contacts
and their connector assemblies that may be located in, and may
connect to, various types of devices, such as portable computing
devices, tablet computers, desktop computers, laptops, all-in-one
computers, wearable computing devices, cell phones, smart phones,
media phones, storage devices, keyboards, covers, cases, portable
media players, navigation systems, monitors, power supplies,
adapters, remote control devices, chargers, and other devices.
These contacts and their connector assemblies may provide pathways
for signals that are compliant with various standards such as
Universal Serial Bus (USB), High-Definition Multimedia Interface
(HDMI), Digital Visual Interface (DVI), Ethernet, DisplayPort,
Thunderbolt, Lightning, Joint Test Action Group (JTAG),
test-access-port (TAP), Directed Automated Random Testing (DART),
universal asynchronous receiver/transmitters (UARTs), clock
signals, power signals, and other types of standard, non-standard,
and proprietary interfaces and combinations thereof that have been
developed, are being developed, or will be developed in the future.
In various embodiments of the present invention, these interconnect
paths provided by these contacts and connectors may be used to
convey power, ground, signals, test points, and other voltage,
current, data, or other information.
[0084] The above description of embodiments of the invention has
been presented for the purposes of illustration and description. It
is not intended to be exhaustive or to limit the invention to the
precise form described, and many modifications and variations are
possible in light of the teaching above. The embodiments were
chosen and described in order to best explain the principles of the
invention and its practical applications to thereby enable others
skilled in the art to best utilize the invention in various
embodiments and with various modifications as are suited to the
particular use contemplated. Thus, it will be appreciated that the
invention is intended to cover all modifications and equivalents
within the scope of the following claims.
* * * * *