Information
-
Patent Grant
-
6227877
-
Patent Number
6,227,877
-
Date Filed
Monday, November 23, 199825 years ago
-
Date Issued
Tuesday, May 8, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Donovan; Lincoln
- Lee; Richard K.
-
CPC
-
US Classifications
Field of Search
US
- 439 83
- 439 493
- 439 495
- 439 876
-
International Classifications
-
Abstract
An electrical contact includes a main body having a contact arm (11) extending from a lower portion thereof, a tail (13) extending from an upper portion thereof, and a retainer (13) projecting from the main body between the contact arm and the tail. A cutout (133) is defined in a surface of the tail opposite a surface designed to engages with a PCB. A guiding slot (132) is defined in the main body of the contact between the tail and the contact arm opposite the retainer. When the tail is soldered to the PCB, any excess solder will flow along the contact. The cutout provides an obstruction and the guiding slot provides a surface area for the solder to solidify on the contact without covering a portion of the contact arm and hindering signal transmission.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrical contact, and particularly to an electrical contact for surface mounting to a printed circuit board whereby excess solder will not hinder signal transmission.
2. The Prior Art
The trend of the computer industry continues toward miniaturization. Notebook and hand held computers both require an efficient use of internal space to include the necessary hardware within a housing of limited size. In desktop computers, a printed circuit board (PCB) is commonly provided with through holes for connecting components on one surface with components on the opposite surface of the PCB. However, such through holes occupy too much space on the PCB. Therefore, a surface mounting contact
4
, as shown in
FIGS. 3 and 4
, has been introduced for surface mounting to both sides of a PCB
3
.
The contact
4
includes a contacting end
41
for electrically engaging with a contact pad formed on an electrical card (not shown), a tail
42
opposite the contacting end
41
for surface mounting to the PCB
3
, and a retaining portion
43
formed between the contacting end
41
and the tail
42
for retention in a housing
33
of an SO DIMM connector. A continuous face
44
is formed between the tail
42
and the contacting end
41
opposite the retaining portion
43
. The tail
42
is electrically engaged with a contact pad
31
on the PCB
3
by means of solder
32
. After surface mounting of the connector to one side of the PCB
3
, the PCB
3
with the associated connector is handled in an upside-down manner to surface mount other components on the other side of the PCB, so that liquefied solder or excess solder
32
has a tendency, due to gravity, to flow downward along the continuous face
44
and cover a substantial portion of the contacting end
41
. Since the contacting end
41
is gold-coated for facilitating high speed signal transmission, the excess solder
32
formed on the contacting end
41
will hinder signal transmission.
Hence, an improved electrical contact is needed to overcome the disadvantages of surface mount soldering conventional electrical contacts.
SUMMARY OF THE INVENTION
Accordingly, an objective of the present invention is to provide an electrical contact defining a guiding slot in a main body thereof for increasing the surface area of the contact whereby excess solder will solidify within the slot and will not adversely affect signal transmission.
An additional objective of the present invention is to provide an electrical contact defining a cutout in a tail thereof for obstructing the flow of excess solder along the contact when the contact is surface mounted to a PCB.
To fulfill the above mentioned objectives, an electrical contact in accordance with the present invention electrically connects a connector with a PCB. The contact includes a main body having a contact arm extending from a lower portion thereof for engaging with a card inserted into the connector, a tail extending from an upper portion thereof for being surface mounted to the PCB, and a retainer projecting from the main body between the contact arm and the tail for supporting the contact within a housing of the connector. A cutout is defined in a surface of the tail opposite the surface which engages with the PCB. A guiding slot is defined in the main body of the contact between the tail and the contact arm opposite the retainer. When the tail is soldered to the PCB, any excess solder will flow downward from the PCB and along the contact. The cutout provides an obstruction and the guiding slot provides sufficient surface area for the solder to solidify on the contact without covering a portion of the contact arm and hindering signal transmission.
These and additional objects, features, and advantages of the present invention will become apparent after reading the following detailed description of the preferred embodiment of the present invention taken in conjunction with the appended drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a side view of an electrical contact in accordance with a preferred embodiment of the present invention;
FIG. 2
is a cross-sectional view showing the contact of
FIG. 1
surface mounted to a PCB and received in a housing of a connector;
FIG. 3
is a side view of a conventional electrical contact; and
FIG. 4
is a cross-sectional view showing the contact of
FIG. 3
surface mounted to a PCB and received in a housing of a connector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will be made in detail to the preferred embodiment of the present invention.
Referring to
FIGS. 1 and 2
, an electrical contact
1
in accordance with the present invention connects an electrical connector
2
with a PCB
3
. The contact
1
comprises a main body
10
having a contact arm
11
extending from a lower portion thereof, a tail
13
extending from an upper portion thereof, and a retainer
12
projecting from the main body
10
between the contact arm
11
and the tail
13
.
Please note that the present invention is specifically designed for use with assembly procedures wherein:
(a) the contact
1
is soldered to a lower surface of the PCB
3
(with the soldering step occurring while the contact
1
is beneath the PCB
3
), or
(b) the contact
1
is first soldered to the PCB
3
(from a position above the PCB
3
) and the PCB
3
is later inverted and other components are soldered to an opposite side of the PCB
3
, so that there is a possibility of reflow of the solder attaching the contact
1
to the PCB
3
.
The retainer
12
is received in a first passageway
22
defined in an insulative housing
21
of the connector
2
which may be an SO DIMM connector. The retainer
12
forms a barb
122
on a bottom portion thereof for interferentially engaging with the housing
21
.
The contact arm
11
extends into a second passageway
20
defined in the housing
21
of the connector
2
. The contact arm
11
forms a tip
111
at an end thereof. A gold-coated projection
112
extends from the contact arm
11
near the tip
111
and projects beyond a bottom face of the housing
21
for engagement with a contact pad formed on a card (not shown) inserted into the connector
2
.
The tail
13
is surface mounted to a contact pad
31
formed on the PCB
3
by solder
32
. A cutout
133
is defined in a surface of the tail
13
opposite the surface which engages with the contact pad
31
of the PCB
3
. A guiding slot
132
is defined in the main body
10
of the contact
1
between the tail
13
and the contact arm
11
opposite the retainer
12
. When the tail
13
is soldered to the contact pad
31
, any excess solder
32
will flow downward from the PCB
3
and along the contact
1
. The cutout
133
provides an obstruction and the guiding slot
132
provides sufficient surface area for the solder
32
to solidify on the contact
1
without covering a portion of the contact arm
11
and hindering signal transmission.
While the present invention has been described with reference to a specific embodiment, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications to the present invention can be made to the preferred embodiment by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.
Claims
- 1. An electrical contact for connecting an electrical connector with a PCB, comprising a main body having a contact arm extending from a lower portion thereof, and a tail extending from an upper portion thereof for surface mounting to the PCB, the main body forming a guiding slot between the tail and the contact arm, so that when the tail is soldered to the PCB, any liquefied excess solder will flow downward therefrom along the tail and into the guiding slot where it will solidify, a cutout being defined in a surface of the tail opposite the surface which engages with the PCB for obstructing the flow of excess solder along the tail, and said guiding slot penetrating through the main body in a direction perpendicular to the main body.
- 2. The contact as described in claim 1, wherein a retainer projects from the main body between the contact arm and the tail, and the guiding slot extends opposite said retainer.
- 3. The contact as described in claim 2, wherein the retainer is received in a first passageway defined in an insulative housing of the connector.
- 4. The contact as described in claim 3, wherein the contact arm extends into a second passageway defined in the housing of the connector.
- 5. The contact as described in claim 4, wherein the contact arm forms a tip at an end thereof.
- 6. The contact as described in claim 5, wherein a gold-coated projection extends from the contact arm near the tip and projects beyond a bottom face of the housing.
Priority Claims (1)
Number |
Date |
Country |
Kind |
86219639 |
Nov 1997 |
TW |
|
US Referenced Citations (5)