U.S. patent application number 15/895645 was filed with the patent office on 2018-06-14 for electrical component having pre-soldered surface with flux reservoirs.
The applicant listed for this patent is Antaya Technologies Corporation. Invention is credited to Alexandra Mary Mackin, John Pereira, Matthew J. Scherer.
Application Number | 20180161905 15/895645 |
Document ID | / |
Family ID | 51358065 |
Filed Date | 2018-06-14 |
United States Patent
Application |
20180161905 |
Kind Code |
A1 |
Mackin; Alexandra Mary ; et
al. |
June 14, 2018 |
ELECTRICAL COMPONENT HAVING PRE-SOLDERED SURFACE WITH FLUX
RESERVOIRS
Abstract
A pre-soldered pre-fluxed electrical component or connector,
which can protect the flux from wearing off the surface of solder
during shipping and handling. The electrical component can include
a terminal pad. A layer of solder can be on the terminal pad. The
layer of solder can have a surface with a series of generally
equally spaced apart flux wells formed in the surface of the solder
for protectively storing and retaining flux therein. The flux wells
can have a lateral dimension of at least 0.05 mm and a depth of at
least 0.023 mm that is deep enough for retaining a quantity of flux
therein when flux on the surface of the layer of solder wears off
during shipping and/or handling.
Inventors: |
Mackin; Alexandra Mary;
(West Warwick, RI) ; Pereira; John; (Rehoboth,
MA) ; Scherer; Matthew J.; (Kingston, RI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Antaya Technologies Corporation |
Warwick |
RI |
US |
|
|
Family ID: |
51358065 |
Appl. No.: |
15/895645 |
Filed: |
February 13, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14339628 |
Jul 24, 2014 |
9925611 |
|
|
15895645 |
|
|
|
|
61860487 |
Jul 31, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 13/0465 20130101;
H05K 2201/09745 20130101; B23K 35/22 20130101; B23K 1/203 20130101;
H01B 5/002 20130101; H05K 3/3489 20130101 |
International
Class: |
B23K 1/20 20060101
B23K001/20; H05K 3/34 20060101 H05K003/34; H01B 5/00 20060101
H01B005/00; H05K 13/04 20060101 H05K013/04 |
Claims
1. An electrical component comprising: a terminal pad; and a layer
of solder on the terminal pad, the layer of solder having a surface
with a series of generally equally spaced apart flux wells formed
in the surface of the solder for protectively storing and retaining
flux therein, the flux wells having a lateral dimension of at least
0.05 mm.
2. The electrical component according to claim 1, wherein the flux
wells have a diameter of at least 0.05 mm, and are in a continuous
pattern with at least 0.035 mm spacing in x and y directions.
3. The electrical component according to claim 1, wherein the layer
of solder consists essentially of 66% to 90% indium, 4% to 25% tin,
0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03%
to 4% nickel, and 0.2% to 6% zinc by weight.
4. An electrical component comprising: a terminal pad; and a layer
of solder on the terminal pad, the layer of solder having a surface
with a knurled pattern formed in the surface of the solder for
protectively storing and retaining flux therein.
5. The electrical component according to claim 4, wherein the
knurled pattern comprises a first series of generally equally
spaced apart elongate indentations.
6. The electrical component according to claim 5, wherein the
knurled pattern further comprises a second series of generally
equally spaced apart elongate indentations which cross said first
series at an angle.
7. The electrical component according to claim 4, wherein the layer
of solder consists essentially of 66% to 90% indium, 4% to 25% tin,
0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03%
to 4% nickel, and 0.2% to 6% zinc by weight.
8. A method of protecting flux on a pre-soldered pre-fluxed
electrical component, comprising the steps of: providing the
electrical component with a terminal pad; providing a layer of
solder on the terminal pad, the layer of solder having a surface;
and providing a layer of flux on the layer of solder, at least
portions of the flux filling a series of generally equally spaced
apart flux wells formed in the surface of the solder which
protectively store and retain flux therein from wear during
shipping, the flux wells having a lateral dimension of at least
0.05 mm.
9. The method according to claim 8, further comprising the step of
providing the flux wells with a diameter of at least 0.05 mm, and a
continuous pattern with at least 0.035 mm spacing in x and y
directions.
10. The method according to claim 8, wherein the layer of solder
consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to
9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4%
nickel, and 0.2% to 6% zinc by weight.
11. A method of protecting flux on a pre-soldered pre-fluxed
electrical component comprising the steps of: providing the
electrical component with a terminal pad; providing a layer of
solder on the terminal pad, the layer of solder having a surface;
providing a layer of flux on the layer of solder, at least portions
of the flux filling a knurled pattern formed in the surface of the
solder which protectively stores and retains flux therein from wear
during shipping.
12. The method according to claim 11, further comprising the step
of providing the knurled pattern with a first series of generally
equally spaced apart elongate indentations.
13. The method according to claim 12, further comprising the step
of providing a second series of generally equally spaced apart
elongate indentations which cross said first series at an
angle.
14. The method according to claim 11, wherein the layer of solder
consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to
9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4%
nickel, and 0.2% to 6% zinc by weight.
15. A method of soldering a pre-soldered pre-fluxed electrical
component to a substrate, the electrical component having a
terminal pad with a layer of solder on the terminal pad, the layer
of solder having a surface, a layer of flux being on the layer of
solder, the method comprising the steps of: providing a series of
generally equally spaced apart flux wells formed in the surface of
the solder which protectively store and retain flux therein from
wear during shipping and/or handling, the flux wells having a
lateral dimension of at least 0.05 mm and a depth of at least 0.023
mm; and contacting the pre-soldered pre-fluxed terminal pad to the
substrate and applying heat, the series of generally equally spaced
apart flux wells supplying flux for the soldering operation while
spacing a generally even distribution of portions of the solder
layer away from heat sink contact with the substrate, providing for
even heating and melting of the solder.
16. The method according to claim 15, further comprising the step
of providing the flux wells with a diameter of at least 0.05 mm, a
depth of at least 0.023 mm, and a continuous pattern with at least
0.035 mm spacing in x and y directions.
17. The method according to claim 15, further comprising the step
of providing the flux wells with a diameter of about 0.51 mm, a
depth of about 0.25 mm, and a continuous pattern with about 0.89 mm
spacing in the x and y directions.
18. The method according to claim 15, further comprising the step
of providing interconnected flux wells formed by a grid of
crisscrossing grooves in x and y directions about 0.15 mm wide,
about 0.15 mm deep, and separated from each about by about 0.25
mm.
19. The method according to claim 15, wherein the layer of solder
consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to
9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4%
nickel, and 0.2% to 6% zinc by weight.
Description
RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 14/339,628, filed on Jul. 24, 2014 which
claimed the benefit of U.S. Provisional Application No. 61/860,487,
filed on Jul. 31, 2013. The entire teachings of each of the above
referenced applications are hereby incorporated herein by
reference.
BACKGROUND
[0002] Referring to FIG. 1, in the prior art, an electrical
component 8 such as an electrical connector can have a terminal pad
10 with a pre-soldered solder layer 12 that is generally flat. A
layer of flux 14 such as a rosin based flux that dries and/or
hardens can be applied to the solder layer 12 (FIG. 2). During
shipping and handling, the electrical components can rub against
each other, such as with vibration, and this layer of flux 14 can
flake and chip or wear off, which can adversely affect the
soldering process and provide an inferior or weaker soldered joint.
FIG. 3 depicts the flux layer 14 almost completely wiped from the
solder layer 12, after wiping by hand, to illustrate how much flux
can potentially flake off.
SUMMARY
[0003] The present invention can provide an electrical device,
component or connector, which can protect flux from rubbing,
wearing, scraping, crumbling, flaking or chipping off the surface
of solder, or otherwise removed. The electrical component can
include a terminal pad. A layer of solder can be on the terminal
pad. The layer of solder can have a surface with a series of
generally equally spaced apart flux reservoirs, pits, cavities or
wells formed in the surface of the solder for protectively storing
and retaining flux therein. The flux wells can have a lateral
dimension of at least 0.05 mm and a depth of at least 0.023 mm that
is deep enough for retaining a quantity of flux therein when flux
on the surface of the layer of solder wears off during shipping
and/or handling.
[0004] In particular embodiments, the flux wells can be configured
for retaining quantities of flux therein within the layer of solder
in a generally even lateral spaced apart distribution in x and y
directions across the layer of solder. The flux wells can have a
diameter of at least 0.05 mm, a depth of at least 0.023 mm, and can
be in a continuous pattern with at least 0.035 mm spacing in the x
and y directions. In one embodiment, the flux wells can have a
diameter of about 0.51 mm, a depth of about 0.25 mm, and can be in
a continuous pattern with about 0.89 mm spacing in the x and y
directions. In another embodiment, the flux wells can be
interconnected and formed by a grid of crisscrossing grooves in x
and y directions about 0.15 mm wide, about 0.15 mm deep, and
separated from each other by about 0.25 mm. The electrical
component can include a connector portion extending from the
terminal pad for connection to a desired element. A layer of flux
can be on at least a portion of the layer of solder and fill at
least a portion of the flux wells. The layer of solder can be
formed of a lead free solder composition, and the flux can be a
type suitable for lead free solder compositions.
[0005] The present invention can also provide an electrical device,
component or connector having a terminal pad, and a layer of solder
on the terminal pad. The layer of solder can have a surface with a
series of generally equally spaced apart flux wells formed in the
surface of the solder for protectively storing and retaining flux
therein. The flux wells can have a lateral dimension of at least
0.05 mm.
[0006] In particular embodiments, the flux wells can have a
diameter of at least 0.05 mm, and can be in a continuous pattern
with at least 0.035 mm spacing in x and y directions.
[0007] The present invention can also provide an electrical device,
component or connector, having a terminal pad, and a layer of
solder on the terminal pad. The layer of solder can have a surface
with a knurled pattern formed in the surface of the solder for
protectively storing and retaining flux therein.
[0008] In particular embodiments, the knurled pattern can have a
first series of generally equally spaced apart elongate
indentations. In another embodiment, the knurled pattern can
further include a second series of generally equally spaced apart
elongate indentations which cross the first series of indentations
at an angle.
[0009] The present invention can also provide an electrical device,
component or connector, having a terminal pad, and a layer of
solder on the terminal pad. The layer of solder can have a surface
with a pattern of generally equally spaced apart flux reservoirs
formed in the surface of the solder for protectively storing and
retaining flux therein.
[0010] The present invention can also provide a method of
protecting flux on a pre-soldered pre-fluxed electrical device,
component or connector. The electrical component can be provided
with a terminal pad. A layer of solder can be provided on the
terminal pad. The layer of solder can have a surface. A layer of
flux can be provided on the layer of solder. At least portions of
the flux can fill a series of generally equally spaced apart flux
wells formed in the surface of the solder which protectively store
and retain flux therein from wear during shipping and/or handling.
The flux wells can have a lateral dimension of at least 0.05 mm and
a depth of at least 0.023 mm that is deep enough for retaining a
quantity of flux therein when flux on the surface of the layer of
solder wears off during shipping and/or handling.
[0011] In particular embodiments, the flux wells can be configured
for retaining quantities of flux therein within the layer of solder
in a generally even lateral spaced apart distribution in x and y
directions across the solder. The flux wells can be provided with a
diameter of at least 0.05 mm, a depth of at least 0.023 mm, and a
continuous pattern with at least 0.035 mm spacing in x and y
directions. In one embodiment, the flux wells can be provided with
a diameter of about 0.51 mm, a depth of about 0.25 mm, and a
continuous pattern with about 0.89 mm spacing in the x and y
directions. In another embodiment, interconnected flux wells can be
provided by a grid of crisscrossing grooves in x and y directions
about 0.15 mm wide, about 0.15 mm deep, and separated from each
other by about 0.25 mm. The electrical component can be provided
with a connector portion extending from the terminal pad for
connecting to a desired element. The layer of solder can be
provided as a lead free solder composition and the flux can be a
type suitable for lead free solder compositions.
[0012] The present invention can also provide a method of
protecting flux on a pre-soldered pre-fluxed electrical device,
component or connector including providing the electrical component
with a terminal pad. A layer of solder can be provided on the
terminal pad. The layer of solder can have a surface. A layer of
flux can be provided on the layer of solder. At least portions of
the flux can fill a series of generally equally spaced apart flux
wells formed in the surface of the solder which protectively store
and retain flux therein from wear during shipping. The flux wells
can have a lateral dimension of at least 0.05 mm.
[0013] In particular embodiments, the flux wells can be provided
with a diameter of at least 0.05 mm, and can be in a continuous
pattern with at least 0.35 mm spacing in x and y directions.
[0014] The present invention can also provide a method of
protecting flux on a pre-soldered pre-fluxed electrical device,
component or connector including providing the electrical component
with a terminal pad. A layer of solder can be provided on the
terminal pad. The layer of solder can have a surface. A layer of
flux can be provided on the layer of the solder. At least portions
of the flux can fill a knurled pattern formed in the surface of the
solder which protectively stores and retains flux therein from wear
during shipping.
[0015] In particular embodiments, the knurled pattern can be
provided with a first series of generally equally spaced apart
elongate indentations. In another embodiment, a second series of
generally equally spaced apart elongate indentations can cross the
first series at an angle.
[0016] The present invention can also provide a method of
protecting flux on a pre-soldered pre-fluxed electrical device,
component or connector including providing the electrical component
with a terminal pad. A layer of solder can be provided on the
terminal pad. The layer of solder can have a surface. A layer of
flux can be provided on the layer of solder. At least portions of
the flux can fill a pattern of generally equally spaced apart flux
reservoirs formed in the surface of the solder which protectively
store and retain flux therein from wear during shipping.
[0017] The present invention can also provide a method of soldering
a pre-soldered pre-fluxed electrical device, component or connector
to a substrate. The electrical component can have a terminal pad
with a layer of solder on the terminal pad. The layer of solder can
have a surface. A layer of flux can be on the layer of solder. A
series of generally equally spaced apart flux wells formed in the
surface of the solder protectively store and retain flux therein
from wear during shipping and/or handling. The flux wells can have
a lateral dimension of at least 0.05 mm and a depth of at least
0.023 mm. The pre-soldered pre-fluxed terminal pad can be contacted
to the substrate and heat applied. The series of generally equally
spaced apart flux wells can supply flux for the soldering operation
while spacing a generally even distribution of portions of the
solder layer away from heat sink contact with the substrate,
providing for even heating and melting of the solder.
[0018] In particular embodiments, the flux wells can be provided
with a diameter of at least 0.05 mm, a depth of at least 0.023 mm,
and a continuous pattern with at least 0.035 mm spacing in x and y
directions. In one embodiment, the flux wells can be provided with
a diameter of about 0.51 mm, a depth of about 0.25 mm, and a
continuous pattern with about 0.89 mm spacing in the x and y
directions. In another embodiment, interconnected flux wells can be
provided by a grid of crisscrossing grooves in x and y directions
about 0.15 mm wide, about 0.15 mm deep, and separated from each
other by about 0.25 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing will be apparent from the following more
particular description of example embodiments of the invention, as
illustrated in the accompanying drawings in which like reference
characters refer to the same parts throughout the different views.
The drawings are not necessarily to scale, emphasis instead being
placed upon illustrating embodiments of the present invention.
[0020] FIGS. 1-3 are drawings depicting a terminal pad of a prior
art electrical component having a flat layer of solder (FIG. 1),
having a layer of flaking flux on the solder (FIG. 2), and having
the flux wiped off (FIG. 3).
[0021] FIGS. 4A-4C are drawings depicting a terminal pad of an
electrical component in the present invention showing a flat
surface area (FIG. 4A), showing a series of dimples forming flux
wells, reservoirs or cavities in the layer of solder formed by an
EDM process (FIG. 4B), and an enlargement thereof (FIG. 4C).
[0022] FIGS. 5-7 are drawings of the terminal pad of FIG. 4 having
an EDM surface (FIG. 5), having a layer of flux that has been
subjected to being shipped 3 times (FIG. 6), and having the flux
wiped off (FIG. 7).
[0023] FIG. 8 is an engineering drawing of embodiments of an EDM
electrode for forming flux wells, showing various views and
dimensions.
[0024] FIGS. 9A-9D and 10 are drawings of another embodiment of an
electrical component having a terminal pad in the present invention
with 0.51 mm dia x.0.25 mm deep, flux wells, cavities or
reservoirs, showing a rear bottom perspective view (FIG. 9A), a
bottom view (FIG. 9B), a side view (FIG. 9C), an end view (FIG.
9D), and a bottom perspective view (FIG. 10).
[0025] FIGS. 11-13 are drawings of the terminal pad of FIGS. 9A-10,
having the flux wells or reservoirs (FIG. 11), having a layer of
flux that has been subjected to being shipped 3 times (FIG. 12),
and having the flux wiped off (FIG. 13).
[0026] FIG. 14 is a perspective view of a series of example
electrical components soldered to a surface or substrate for
conducting pull tests.
[0027] FIG. 15 is a bottom view of a prior art base control sample
electrical component having terminal pads coated with solder
without flux wells.
[0028] FIG. 16 is a bottom view of an embodiment of an electrical
component in the present invention having a pattern of flux wells
that are 23 microns deep.
[0029] FIG. 17A is a bottom view of an embodiment of an electrical
component in the present invention having a pattern of flux wells
that are 150 microns deep.
[0030] FIG. 17B is an enlarged view of the pattern of flux wells in
FIG. 17A.
[0031] FIG. 18 is a bottom view of an embodiment of an electrical
component in the present invention having a pattern of flux wells
that are 250 microns deep.
[0032] FIG. 19 is a side sectional view of the terminal pad of the
electrical component of FIG. 18 on a surface or substrate for
soldering.
[0033] FIG. 20 is a graph depicting test results for percentage of
flux coverage on the solder of electrical components versus
destructive pull force.
[0034] FIGS. 21A-21D are drawings of another electrical component
including a terminal pad having a layer of solder with flux
reservoirs, canals or trenches formed by a knurled surface, which
consists of a series of equally spaced apart elongate indentations,
with FIG. 21A being a perspective view, FIG. 21B being a bottom
view, FIG. 21C being a side view, and FIG. 21D being a plan view of
the knurled pattern.
[0035] FIGS. 22A-22D are drawings of another electrical component
including a terminal pad having a layer of solder with flux
reservoirs, canals or trenches formed by a knurled surface, which
consists of first and second series of equally spaced apart
elongate indentations which cross each other at an angle, with FIG.
22A being a perspective view, FIG. 22B being a bottom view, FIG.
22C being a side view, and FIG. 22D being a plan view of the
knurled pattern.
DETAILED DESCRIPTION
[0036] A description of example embodiments of the invention
follows.
[0037] Referring to FIGS. 4A-8, in one embodiment of the present
invention, an electrical device, component or connector 20 can have
about a 3/4 partial circular shaped terminal pad 10 with a layer of
solder 12 formed thereon, which can be generally flat or planar.
The terminal pad 10 is connected to an arm 11 extending therefrom,
which has a connector portion 11a (FIG. 10) for connecting to other
devices, components or conductors, for example by engagement,
soldering or crimping. The layer of solder 12 can have a series or
pattern 15 of generally equally spaced apart protective or storage
flux wells, reservoirs, pits or cavities 16 formed in the exterior
or outer surface or face of the solder 12, such as by EDM
(electrical discharge machining). The flux wells 16 can be
individual, can have a lateral width or diameter of about 0.05 mm
(50 microns), and can be in a continuous pattern extending in the x
and y directions with at least about 0.035 mm (35 microns) spacing
in the x and y directions. An embodiment of an EDM electrode for
forming the flux wells 16 is shown in FIG. 8. As seen in FIG. 5,
the pattern 15 of flux wells 16 does not have to be as precise as
shown in the drawing of FIG. 4 and some flux wells 16 can overlap
each other. The depth of the wells 16, or distance extending into
the layer of solder 12 can be about 25%-50% of the width or
diameter for example, about 0.023 mm (23 microns) deep. The flat
lateral surface area of the layer of solder 12 of the terminal pad
10 prior to forming flux wells 16 shown in the drawing of FIG. 4A
can be 16.25 mm.sup.2, and the surface area including the flux
wells 16 shown in FIG. 4B can be 20.25 mm.sup.2. The addition of
the flux wells 16 in the layer of solder 12 of the electrical
component 20 can increase the surface area of the layer of solder
12 about 24.6% in comparison to just the flat lateral surface area.
The flux wells 16 can have end walls 16a and side walls 16b, to
which the flux 14 can adhere to or cover.
[0038] Referring to FIG. 6, a layer of flux 14 can be pre-applied
to the layer of solder 12. The flux 14 can be a type that dries
and/or hardens, such as an activated rosin based flux for example,
Kester 1544 and AIM RA301. In some embodiments, flux 14 can be
Xersin 514. The flux 14 can cover the flat face or outer surfaces
of the solder 12 and can also fill the flux wells 16. When a
quantity of pre-soldered, pre-fluxed electrical components 20 are
shipped, the vibration and agitation of the electrical components
20 during shipping and/or handling can cause adjacent electrical
components 20 resting or contacting against each other to rub,
wear, scrape, chip, crumble and/or flake the flux 14 off of the
flat surfaces of the solder 12. However, the flux wells 16 can
provide a protective reservoir within the solder 12 for
protectively storing and retaining the flux 14, so that if a large
quantity of flux 14 is scraped or flaked off the flat surfaces of
the solder 12, the flux wells 16 can still protectively retain
sufficient flux 14 for effectively soldering the terminal pad 20 to
a surface. The size of the individual flux wells 16 can be large
enough and the spacing or density adequate to store sufficient flux
14, and also provide protection against adjacent electrical
components 20 contacting and removing flux 14. The surfaces of the
solder 12 adjacent to or surrounding the flux wells 16 can provide
raised or outwardly extending or facing protective ridges, bumps,
projections, surfaces or structures 17 (FIG. 4C) for protecting the
flux 14 within the flux wells 16. The ridges 17 can be connected or
interconnected together. FIG. 7 shows that with the flux 14 wiped
off the flat surfaces of the solder 12, that sufficient flux 14 can
be retained within the wells 16. Heat introduced during soldering
can vaporize the flux 14 within the wells 16. In some embodiments
the heat introduced can be about 500.degree. F.
[0039] Electrical component 30, depicted in FIGS. 9A-13, is another
embodiment having a terminal pad 10 with a layer of solder 12 in
which the protective wells, reservoirs, pits or cavities 16 are
larger than in FIGS. 4A-7 and can store more flux 14 in each well
16. The terminal pad 10 can be the same shape and size as in FIGS.
4A-7. The flux wells 16 can be individual, can have a lateral width
or diameter of about 0.51 mm (510 microns), and can be in a
continuous series or pattern 32 extending in the x and y directions
with about 0.89 mm (890 microns) spacing in the x and y directions,
which can be center to center. The depth of the flux wells 16 or
distance extending into solder layer 12, can be about 0.25 mm (250
microns). Since each individual flux well 16 holds more flux 14
than in FIGS. 4A-7, the spacing can be larger. The flux 14 can
cover or adhere to the end walls 16a and side walls 16b of the flux
wells 16. The flux wells 16 can be formed in the outer or exterior
surface or face of the layer of solder 12 by suitable methods
including EDM processes, rolling, molding or stamping. As can be
seen in FIGS. 12 and 13, large quantities of flux 14 can be
protectively stored and retained within the flux wells 16 despite
rubbing, wearing, scraping, chipping, crumbling or flaking during
shipping and/or handling, or if wiped off the flat surface, can
still provide enough flux 14 to provide a viable or sufficient
soldered joint. The larger and deeper flux wells 16 of electrical
component 30 can in some cases better protect and hold flux 14 than
smaller or shallower wells 16 in electrical component 20. The
surfaces of the solder 12 adjacent to or surrounding the flux wells
16 can provide raised or outwardly extending protective ridges,
bumps, projections, surfaces or structures 17 for protecting the
flux 14 within the flux wells 16. The ridges 17 can be connected or
interconnected together and can have a generally flat outer or
exterior surface or face. Chipping and scraping over wells 16 that
are shallow can in some instances more easily remove flux 14 from
the wells 16, than from a deeper well 16.
[0040] The layer of solder 12 in some embodiments can be a nonlead
or lead free solder composition. In one embodiment, the lead free
solder composition can be about 65% indium, 30% tin, 4.5% silver
and 0.5% copper, by weight. In other embodiments, other suitable
lead free compositions can be used for the layer of solder 12 for
example, about 66%-90% indium, 4%-25% tin, 0.5%-9% silver, 0.1%-8%
antimony, 0.03%-4% copper, 0.03%-4% nickel, and 0.2%-6% zinc, by
weight, and can further include in some embodiments, about
0.01%-0.3% germanium. An example of such a solder composition is
about 75% indium, 15% tin, 6% silver, 1% antimony, 1% copper, 1%
nickel, and 1% zinc. Typically, the flux 14 used for nonlead solder
compositions is brittle, and easily rubs, wears, flakes, cracks,
crumbles or chips off the layer of solder 12. In other embodiments,
the layer of solder 12 can be a leaded solder composition. In one
embodiment, the leaded solder composition can be about 25% tin, 62%
lead, 10% bismuth and 3% silver, by weight. In other embodiments,
other suitable leaded compositions can be used for the layer of
solder 12. Some types of flux 14 used with leaded solder
compositions can be brittle similar to the flux 14 for nonlead
solder compositions, while other types of flux 14 used with leaded
compositions can be more resistant to wear, chipping and
flaking.
[0041] Referring to FIG. 14, another embodiment of electrical
components, such as example electrical devices, components or
connectors 60, are shown soldered to a substrate or surface 66
which can be glass with a metalized soldering contact or terminal
pad surface, such as automotive glass. The electrical components 60
can have two spaced apart generally rectangular terminal pads 10
which are connected together by a raised bridge portion 62. Each
terminal pad 10 can have dimensions of about 4.times.7 mm, or about
28 mm.sup.2 in area, with two terminal pads 10 collectively having
about 56 mm.sup.2 area. A connector portion such as a blade
connector 64 can extend from the bridge portion 62 for mating with
a desired element, such as a mating female flat socket, which can
be at the end of or extend from a conductor or a device.
[0042] Referring to FIGS. 15-18, four different versions, types or
embodiments of electrical component 60 were prepared, soldered to a
substrate 66, and destructive pull tested to determine the pull
force required to pull the electrical components 60 free from the
substrate 66. Referring to FIG. 15, electrical component or
connector 68 is a non-inventive base control sample or prior art
embodiment of an electrical component 60 to provide baseline or
control sample test results for comparing with embodiments of the
present invention shown in FIGS. 16-18. The two terminal pads 10 of
electrical component 68 have a prior art conventional or standard
layer of solder 12 on the bottom surfaces and do not have flux
wells 16. The process that applied the layer of solder 12 to the
terminal pads 10 of the electrical component 68 inherently provided
a surface finish 69 on the exterior surface of the solder 12 which
can have a surface roughness of about 5 microns (0.005 mm), or have
surface pits about 5 microns deep. The layer of flux 14 was then
applied over the exterior surface of the layer of solder 12. The 5
micron deep pits are too small to be considered flux wells 16 in
the present invention.
[0043] Referring to FIG. 16, electrical device, component or
connector 70 is an embodiment of component 60 in the present
invention. The two terminal pads 10 of electrical component 70 have
a layer of solder 12 formed on the bottom surfaces. The layer of
solder 12 on the terminal pads 10 has a continuous series or
pattern 15 of generally equally sized and spaced apart protective
or storage flux wells, reservoirs, pits or cavities 16 formed or
extending in the outer exterior surface, such as by EDM, similar to
electrical component 20, which are about 0.023 mm (23 microns)
deep. The flux wells 16 can be individual, can have a diameter of
about 0.05 mm (50 microns) and can be spaced apart at least about
0.035 mm (35 microns) in the x and y directions, which in some
situations or portions can be center to center. Some wells 16 can
overlap each other. The layer of flux 14 was then applied over the
layer of solder 12, covering the exterior surface of the solder 12
and filling the flux wells 16. The depth of the flux wells 16, and
the protective adjacent or surrounding ridges 17 that extend
adjacent to, around or surround the flux wells 16, can provide
protection against wear for the flux 14 contained within the flux
wells 16.
[0044] Referring to FIG. 17A, electrical device, component or
connector 72 is another embodiment of component 60 in the present
invention. The two terminal pads 10 of electrical component 72 have
a layer of solder 12 formed on the bottom surfaces. The layer of
solder 12 on the terminal pads 10 has a continuous series, pattern
or grid 74 of crisscrossing elongate grooves, trenches or
reservoirs 19 in x and y directions at right angles along
longitudinal axes 75, forming interconnected generally equally
sized and spaced apart protective or storage flux wells,
reservoirs, pits or cavities 16 formed or extending in the exterior
surface (FIG. 17B).
[0045] The flux wells 16 can surround adjacent individual spaced
apart raised or outwardly extending protective ridges, bumps,
projections, surfaces or structures 17 which protect the flux 14
contained within the flux wells 16 from wear. For example, four
flux wells 16 can surround a generally square protective ridge 17
on four sides, in repeating fashion, extending in the x and y
directions. Each protective ridge 17 can be separated from
neighboring protective ridges 17 by a flux well 16. The grooves 19
forming the flux wells 16 longitudinally connect ends of the flux
wells 16 to each other along the x and y directions, and the
protective ridges 17 separate the lateral sides of the flux wells
16 from each other in the x and y directions. In one embodiment,
the flux wells 16 can be about 0.15 mm (150 microns) wide or in the
lateral direction, and can be laterally separated by square ridges
17 about 0.25 mm (250 microns) from each other in the x and y
directions. Since the flux wells 16 longitudinally extend in a
connected manner, the length of each flux well 16 extending along a
side of a ridge 17 can be considered to be either 0.25 mm (250
microns) long or 0.55 mm (550 microns) long in the longitudinal
direction, depending upon if the length of the flux well 16 is
measured to be equal only to the length of the side of a square
ridge 17, or to also include the width of the two crossing flux
wells 16. The depth of the grooves 19 and the flux wells 16
extending into the layer of solder 12 can be about 0.15 mm (150
microns) deep. The longitudinal axes 75 of the grooves 19 and flux
wells 16 can be parallel and laterally spaced apart from each other
about 0.4 mm (400 microns) centerline to centerline. The layer of
flux 14 was then applied over the exterior surface of the layer of
solder 12 and filling the flux wells 16. The flux 14 can cover or
adhere to the end walls 16a and side walls 16b of the flux wells
16. The depth of the flux wells 16 and the protective ridges 17
adjacent to and surrounded by the flux wells 16 can provide
protection against wear for the flux 14 contained within the flux
wells 16. Although the protective ridges 17 are surrounded by flux
wells 16, rather than surrounding the flux wells 16 with the
protective ridges 17, the depth of the flux wells 16 and the
consistent spacing of the protective ridges 17 in the x and y
directions generally along a flat plane in a lateral manner across
the solder 12, are able to provide sufficient protection against
wear of the flux 14, such as by rubbing, chipping, flaking and
crumbling.
[0046] Referring to FIG. 18, electrical device, component or
connector 76 is another embodiment of component 60 in the present
invention. The two terminal pads 10 of electrical component 76 have
a layer of solder 12 formed on the bottom surfaces. The layer of
solder 12 on the terminal pads 10 has a continuous series or
pattern 32 of generally equally sized and spaced apart protective
or storage flux wells, reservoirs, pits or cavities 16 formed or
extending therein similar to electrical component 30, which can be
individual, can be about 0.51 mm (510 microns) in lateral width or
diameter and about 0.25 mm (250 microns) deep. The flux wells 16
can be in a continuous series or pattern extending in the x and y
directions with about 0.89 mm (890 microns) spacing, which can be
center to center. The layer of flux 14 was then applied over the
exterior surface of the layer of solder 12 and filling the flux
wells 16. The depth of the flux wells 16 and the protective ridges
17 surrounding the flux wells 16 can provide protection for the
flux 14 contained within the flux wells 16. The ridges 17 can be in
the form of a series or pattern of interconnected generally
circular rings, walls or ridges 17, with each circular ridge 17
being raised or outwardly extending and surrounding a flux well 16.
The flux wells 16 and the circular ridges 17 can be generally
aligned along a planar or flat surface of the solder 12 laterally
along x and y directions or axes. The ridges 17 can be formed by
flat exterior surfaces of the layer of solder 12 and can have a
generally flat outer face. As seen in FIG. 18, in some embodiments,
the circular ridges 17 surrounding each flux well 16 can be an
annular ring with a narrow width, such that a majority of the
lateral surface area of the solder 12 facing outwardly is within a
flux well 16, and a majority of the flux 14 is protected from wear.
The width or thickness of the wall of the circular ridges 17 can be
about 1/4 the width or diameter of the flux wells 16, for example
in some embodiments, about 0.12 mm (120 microns). At least 60%,
sometimes 70% or 75% of the surface of the layer of solder 12 on
the terminal pads 10 of electrical component 76 can be within a
flux well 16, thereby protecting a corresponding percentage of flux
14 from wear within the flux wells 16. The interconnected circular
ridges 17 can provide a raised or outwardly extending protective
lattice ridge structure for protecting the flux 14 within the flux
wells 16 from chipping, flaking, rubbing, crumbling or wear from
other connectors during shipping and/or handling.
[0047] Tests were conducted for the electrical components 68, 70,
72 and 76 of FIGS. 15-18, to compare destructive pull test results
of soldered electrical components 70, 72 and 76 in the present
invention (FIGS. 16-18) having flux wells 16 in the layer of solder
12, with a soldered non-inventive baseline or control prior art
electrical component 68 (FIG. 15) having a standard layer of solder
12. Tests were conducted for both lead free solder compositions and
leaded solder compositions. The following electrical components
were tested:
[0048] 1. Prior art electrical component 68 shown in FIG. 15 having
5 micron pits that are not considered to be flux wells.
[0049] 2. Electrical component 70 shown in FIG. 16 having 23 micron
pits or flux wells.
[0050] 3. Electrical component 72 shown in FIGS. 17A and 17B having
150 micron pits or flux wells.
[0051] 4. Electrical component 76 shown in FIG. 18 having 250
micron pits or flux wells.
[0052] All the electrical components 68, 70, 72, and 76 have the
same basic connector 60, but the layers of solder 12 have different
configurations.
[0053] Test 1--Lead Free Solder
[0054] 50 samples of each electrical component 68 (FIG. 15 prior
art base control, 5 micron pits), electrical component 70 (FIG. 16,
23 micron pits), electrical component 72 (FIG. 17A, 150 micron
pits) and electrical component 76 (FIG. 18, 250 micron pits) having
a layer of a lead free solder 12 with a composition of about 65%
indium, 30% tin, 4.5% silver and 0.5% copper, were sprayed with a
flux 14 suitable for lead free solder compositions (standard AIM
RA301 blue flux), under normal production processes and allowed to
dry overnight. All samples were then packaged with no packing
filler to allow for movement of parts within the package and
shipped via United Parcel Service from one location in Rhode Island
to another location within Rhode Island, to rub or wear off
portions of flux 14 from the terminal pads 10 by the shipping and
handling. Eight samples of each different type or embodiment of
electrical component 68, 70, 72 and 76 were then soldered to test
glass substrates 66. The prior art base control electrical
components 68 (FIG. 15, 5 micron pits) were soldered by a standard
Antaya Q-Box soldering device at 650 watt seconds. The electrical
components 70 (FIG. 16, 23 micron pits), electrical components 72
(FIG. 17A, 150 micron pits) and electrical components 76 (FIG. 18,
250 micron pits) of the present invention were soldered at 600 watt
seconds. The flux wells 16 in the solder 12 of the electrical
components 70, 72 and 76 of the present invention provide a more
uniform heat distribution across the layer of solder 12 and allows
less input heat to be used for soldering than with layers of solder
12 that do not have flux wells 16 of the prior art base control
electrical component 68, for comparable soldering characteristics.
Using less input heat when soldering to a glass substrate 66 is
desirable because it reduces the chance of damaging or cracking the
glass, and also shortens soldering time. The eight samples of each
different component 68, 70, 72 and 76 were then destructive pull
tested to determine the force required to pull the soldered
electrical components free from the substrate 66. The average pull
force in pounds for the eight samples for each different type of
electrical component having a layer of lead free solder 12, is
provided below in Table 1.
TABLE-US-00001 TABLE 1 Pull Tests/Lead Free Solder Average Pull
Test Electrical Component for Eight Samples FIG. 15 base control
component 68, 135.8 lbs. 5 micron pits FIG. 16 component 70, 153.6
lbs. 23 micron pits FIG. 17A component 72, 158.6 lbs. 150 micron
pits FIG. 18 component 76, 164.4 lbs. 250 micron pits
[0055] As can be seen in Table 1, the electrical components 70, 72
and 76 of FIGS. 16, 17A and 18 of the present invention, which have
the flux wells 16, recorded considerably higher average pull test
results than the base control prior art electrical component 68 of
FIG. 15. The pull tests for the electrical component 70 of FIG. 16
(23 micron pits) averaged about 17 lbs. higher, the electrical
component 72 of FIG. 17A (150 micron pits) averaged about 22.8 lbs.
higher, and the electrical component 76 of FIG. 18 (250 micron
pits) averaged about 28.6 lbs. higher. The flux wells 16 in the
present invention are able to protect and retain more flux 14 on
the surface of the solder 12 from wear during shipping and handling
than the prior art base control electrical component 68 of FIG. 15
that does not have flux wells 16. The ability to increase the
amount of flux 14 retained on the surface of the solder 12 after
wear from shipping and handling with flux wells 16 in the present
invention can increase the strength of the soldered joint to a
substrate 66, which is evidenced by the increase in pull strength
over the base control prior art component 68 (FIG. 15). Although
the prior art base control component 68 of FIG. 15 has 5 micron
pits, it is evident by the low pull test results, that the 5 micron
pits are too small to function as, or to be considered flux wells
16 for protecting flux 14 from wearing off, in comparison with the
tested embodiments of the present invention. Lower pull test
results can correlate to more flux 14 wearing off, resulting in a
weaker soldered joint. The increase in pull strength in the present
invention between the electrical components 70, 72 and 76 of FIGS.
16, 17A and 18, with increase in the size of the flux wells 16, can
be due to the fact that larger flux wells 16 (width and/or depth)
can protect and retain a greater amount of flux 14 on the solder 12
from wear during shipping and handling than smaller flux wells.
[0056] FIG. 19 shows a terminal pad 10 of electrical component 76
on a substrate 66 for soldering with flux 14 retained in a pattern
32 of flux wells 16 that extend 250 microns deep in the solder 12,
and some flux 14 still on the outer surface of the solder 12 after
wear from shipping and handling. The thickness of the flux 14 on
the bottom or outer face of ridges 17 are shown oversized for
illustrative purposes, and can be thin so that the ridges 17 can
generally contact or be close to contacting the substrate 66. The
raised or outwardly extending ridges 17 surrounding the flux wells
16 raise or evenly separate or space portions 80 of solder 12
within flux wells 16 above or away from the substrate 66 evenly in
the x and y directions and out of contact with the substrate 66.
This takes the raised or spaced portions 80 of solder 12 out of
heat sink contact with the substrate 66, allowing for more even
heating and melting of the solder 12 when applying heat from the
soldering device during soldering, and at a lower temperature or
with less input heat for a shorter period of time. The raised
portions 80 formed by the flux wells 16 also provide space for
which the solder 12 and flux 14 to flow during soldering. This can
also increase the pull test results for the electrical components
that have the larger flux wells 16. The larger the flux wells 16,
the further away portions 80 of solder 12 within the flux wells 16
can be spaced from the substrate 66 to be soldered to, and the more
room that is available for solder 12 to move and flow. The flux
wells 16 and the ridges 17 can also provide a more consistent heat
distribution across the soldering surface by forming equally sized
and spaced solder heat sink contact points onto the substrate 66 in
x and y directions, and also provides equally sized and spaced heat
flow paths.
[0057] Test 2--Leaded Solder
[0058] 50 samples of each electrical component 68 (FIG. 15 prior
art base control, 5 micron pits), electrical component 70 (FIG. 16,
23 micron pits), electrical component 72 (FIG. 17A, 150 micron
pits) and electrical component 76 (FIG. 18, 250 micron pits) having
a layer of leaded solder 12 with a composition of about 25% tin,
62% lead, 10% bismuth and 3% silver, were sprayed with a flux 14
suitable for leaded solder compositions (Xersin 514 red flux),
under normal production processes and allowed to dry overnight. All
samples were then packaged with no packing filler to allow for
movement of parts within the package and shipped via United Parcel
Service from one location in Rhode Island to another location
within Rhode Island, to rub or wear off portions of flux 14 from
the terminal pads 10 by wear against adjacent components, by the
shipping and handling. Eight samples of each different type or
embodiment of electrical component 68, 70, 72 and 76 were then
soldered to test glass substrates 66 at 950 watt seconds using a
standard Antaya Q-Box soldering device. The eight samples of each
different component 68, 70, 72 and 76 were then destructive pull
tested to determine the force required to pull the soldered
electrical components free from the substrate 66. The average pull
force in pounds for the eight samples for each different type of
electrical component having a layer of leaded solder is provided
below in Table 2.
TABLE-US-00002 TABLE 2 Pull Tests/Leaded Solder Average Pull Test
Electrical Component for Eight Samples FIG. 15 base control
component 68, 185.8 lbs. 5 micron pits FIG. 16 component 70, 167.8
lbs. 23 micron pits FIG. 17A component 72, 152.1 lbs. 150 micron
pits FIG. 18 component 76, 169.9 lbs. 250 micron pits
[0059] The flux 14 used with leaded solder 12 is often not as prone
to chipping and flaking, rubbing and wearing as flux 14 used with
lead free solder. As a result, with leaded solder, the prior art
base control component 68 of FIG. 15 shipped within Rhode Island
does not have a lower pull test than the components 70, 72 and 76
of FIGS. 16, 17A and 18 that have the flux wells 16 in the present
invention. Although the components 70, 72 and 76 of FIGS. 16, 17A
and 18 in the present invention had lower pull test results than
the prior art base control component 68 of FIG. 15, the force
numbers are still well above the minimum desired force threshold of
22.4 lbs. for soldering to a glass substrate 66. By comparing the
results of Table 1 for lead free solder with the results of Table 2
for leaded solder, it can be seen that the pull test force results
for the components 70, 72 and 76 of FIGS. 16, 17A and 18 with
leaded solder 12 generally have a similar numerical force as the
pull test force results for the components 70, 72 and 76 of FIGS.
16, 17A and 18 with lead free solder 12. As a result, the use of
the flux wells 16 in the present invention can provide generally
numerically or statistically consistent and similar pull test force
results that exceed the desired minimum requirement, for both
leaded and lead free solder compositions, so that the same
configuration of components 70, 72 and 76 of FIGS. 16, 17A and 18
and flux wells 16 can be used for both leaded and lead free solder
12. This can make manufacturing process changes between leaded and
lead free solder components quick and easy by merely changing the
type of solder and flux used in the manufacturing machinery.
Although there might not have been a pull test performance
advantage in having flux wells 16 in a layer of leaded solder 12,
for short shipping distances, an advantage is that the
manufacturing processing equipment does not have to be changed when
changing over from electrical components having lead free solder 12
to electrical components having leaded solder 12. Although the
tested flux wells 16 for short shipping distances did not provide
increased performance for leaded solder 12, the ability of the same
manufacturing equipment and electrical component design to protect
and retain a sufficient amount of more brittle flux 14 on lead free
solder 12 to provide a consistent stronger soldered joint is
advantageous. However, it is expected that for longer shipping
distances, for example cross country or overseas, that much more
flux 14 would wear off the layer of leaded solder 12 on the prior
art base control component 68 of FIG. 15, and that the test results
might more closely resemble the test results for lead free solder.
Consequently, for short shipping distances, the flux wells 16
provide immediate increased solder joint performance for pre-fluxed
lead free solder 12, and for long distance shipping, should provide
increased solder joint performance for pre-fluxed leaded solder 12
in addition to the pre-fluxed lead free solder 12.
[0060] Referring to FIG. 20, sample electrical components 60 were
soldered to a substrate 66 with varying flux 14 coverage
percentages on the layer of solder 12 that is on terminal pads 10,
and destructive pull tested, to determine the desired amount of
flux retention coverage that the flux wells 16 should retain. The
curve of the graph shows a generally flat pull force line between
50% and 100% flux coverage, so that that statistically, flux
coverage between 50% and 100% provides about the same pull test
results (between about 157 and 163 lb. average). The curve of the
graph rises more rapidly upwardly from 25% flux coverage to 50%
flux coverage. As can be seen by comparing the pull test force
results of Tables 1 and 2, with the pull test force results
provided in the graph of FIG. 20, the pull test force numbers for
the present invention components 70, 72 and 76 having the flux
wells 16 with both lead free and leaded solder compositions are
generally statistically comparable to the pull test figures for at
least about 50% flux coverage or higher (the 50% to 100% range). It
appears that based on the test results, the flux wells 16 in the
present invention are able to provide protection for flux 14 on the
solder 12 of terminal pads 10 of electrical components 70, 72 and
76 from wear during shipping and handling to preserve on average,
generally, statistically or approximately, at least about 50% or
higher coverage of flux 14 on the solder 12.
[0061] Referring to Table 1, the average pull test results for the
base control prior art electrical component 68 of FIG. 15 with lead
free solder 12 and corresponding flux 14, was 135.8 lbs. Referring
to the graph of FIG. 20, this would correlate to much less than 50%
flux coverage, somewhere around 35% flux coverage. This means a
high percentage of flux 14 was worn off (about 65%) merely by
shipping within the state of Rhode Island. As can be seen, the 5
micron pits in the layer of solder 12 of the prior art base control
component 68 do not provide protection for flux 14, and therefore
do not function as and cannot be considered flux wells. Shipment of
the base control prior art electrical component 68 across the
country or overseas would likely provide a bigger difference
between the pull test results between the base control prior art
electrical component 68 and the electrical components 70, 72 and 76
in the present invention for lead free solder 12 and corresponding
flux 14.
[0062] Referring to Table 2, the average pull test results for the
base control prior art electrical component 68 of FIG. 15 with the
leaded solder 12 and corresponding flux, was 185.8 lbs. Referring
to the graph of FIG. 20, this would suggest that a sufficient
amount of flux 14 can be retained on the surface of the solder 12,
above 50%, for leaded solder 12 compositions and corresponding flux
14, for prior art base control electrical components 68 without
flux wells 16, for a short shipment distance within Rhode Island.
As previously mentioned, shipment of electrical components having
leaded solder 12 cross country or overseas would be expected to
likely cause a lot more wear of flux 14, and provide test results
close to the results for lead free solder 12.
[0063] Even if the flux wells 16 do not provide an increase in pull
force performance with leaded solder, such as for short shipping
distances, with industry using both lead free and leaded solder
compositions, the electrical components 70, 72 and 76 having flux
wells 16 in the present invention can provide generally,
statistically at least about 50% flux 14 coverage after wear from
shipping and/or handling for both lead free and leaded solder 12
compositions and corresponding fluxes 14. It can be seen that the
flux wells 16 tested having widths or diameters ranging from about
0.05 mm (50 microns) to 0.51 mm (510) microns, depths ranging from
about 0.023 mm (23 microns) to 0.25 mm (250 microns), and spacing
ranging from about 0.035 mm (35 microns) to 0.89 mm (890 microns),
provided sufficient flux 14 protection and retention from wear
during shipping and handling for obtaining consistent acceptable
soldered joints.
[0064] FIGS. 21A-21D depict an embodiment of an electrical
component 40, which can be a solder clad strip or buss bar
assembly. The buss bar assembly can have an elongate soldering
surface or terminal pad 10, with an elongate generally rectangular
or ribbon shaped layer of solder 12. An elongate linear knurled
pattern 18 can be formed in the layer of solder 12 with a knurling
wheel to form linear or elongate flux reservoirs, canals or
trenches 18a which can protectively store and retain flux 14 in
spaced apart parallel linear or elongate lines. The flux trenches
18a can consist of a continuous series of generally equally spaced
apart elongate parallel indentations within the solder 12, which
can be linear as shown, and also perpendicular to the longitudinal
direction of the terminal pad 10, and solder 12. The flux trenches
18a can be spaced apart, by about 1/16 inch (1.6 mm), can be about
0.1-0.36 mm wide and about 0.01 mm deep. In some embodiments, the
width of the flux reservoirs 18a can be angled.
[0065] FIGS. 22A-22D depict an embodiment of an electrical
component 50, which can be a solder clad strip with a crimped
blade. The electrical component 50 can have an elongate soldering
surface or terminal pad 10 with an elongate generally rectangular
or ribbon shaped layer of solder 12. An elongate linear knurled
pattern 19 can be formed in the layer of solder 12 with a knurling
wheel, and differs from knurled pattern 18 in that it includes
linear or elongate flux reservoirs, canals or trenches 19a and 19b
for protecting, storing and retaining flux 14. The flux trenches
19a and 19b can each consist of a continuous series of generally
equally spaced apart elongate parallel indentations, which can be
linear, at an angle relative to the longitudinal direction of the
terminal pad 10, and crossing each other as shown, to form a
diamond shaped knurled pattern. The trenches 19a and 19b can have
the same or similar spacing, width and depth as trenches 18a, and
can be connected or interconnected with each other. The trenches
19a and 19b can have double the flux capacity of trenches 18a.
[0066] The knurled patterns 18 and 19 of electrical components 40
and 50 do provide some flux protection and better soldered joints
than if the knurled patterns 18 and 19 were omitted. It has been
determined that the flux wells 16 of electrical connectors 20, 30,
70, 72 and 76, provide further improved performance in obtaining a
suitable soldered joint than provided by the knurled canal or
trench patterns 18 and 19 of electrical components 40 and 50. The
deeper and closer x-y spacing of the flux wells 16 in connectors
20, 30, 70, 72 and 76 can provide better consistent spaced apart
x-y flux retention from wear and distribution flux or solder flow,
as well as provide consistent x-y spaced apart small intermittent
equal sized locations of raised or outwardly extending solder
portions or ridges 17 that touch the surface or substrate 66, to be
soldered in heat sink contact.
[0067] While this invention has been particularly shown and
described with references to example embodiments thereof, it will
be understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
scope of the invention encompassed by the appended claims.
[0068] For example, although some dimensions and shapes have been
described, these can vary depending upon the situation at hand. The
flux wells 16 are often but do not have to be round, and can
include noncircular curves or can be polygonal, or can have linear
line portions connected together. The flux reservoirs or trenches
18a, 19a and 19b do not have to be linear, but can have angles
and/or curves. Although particular dimensions have been described,
it is understood that dimensions can vary depending on the
situation at hand. In addition, although certain terms of
orientation have been used, this is not meant to limit orientation
of features or components in the present invention. Furthermore,
various features for the present invention can be combined together
or omitted. It is also understood that electrical devices,
components or connectors in the present invention can have
different configurations than the examples shown and described.
* * * * *