Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
2001-08-24
2004-04-20
Vo, Peter (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S832000, C029S843000, C029S854000, C174S260000, C228S006200, C257S773000, C361S760000, C361S774000
Reexamination Certificate
active
06722029
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of electronic circuits, and, more particularly, to a method of mounting electronic components. Further, the present invention is particularly applicable to the mounting of integrated circuits (ICs) on printed circuit boards (PCBs), including flexible printed circuit boards, though the present invention may also be used to mount other components on PCBs, or to mount components on other types of carriers, for example.
BACKGROUND OF THE INVENTION
There are many situations where it is desirable to minimize the overall dimensions of an electronic device. One example is a miniature video camera using an image sensor formed as a single IC.
An IC is generally mounted on a PCB having a larger area. Such an arrangement is illustrated in
FIG. 1
in a surface mount form. An IC
10
has a plurality of contacts
12
extending down the side face
14
and under the undersurface
16
of the IC
10
. The IC
10
is mounted on a PCB
18
which has a plurality of copper contact pads
20
. The contact
12
is connected to the contact pad
20
by a body
22
of solder which includes a planar portion
22
A and a fillet
22
B. This arrangement requires the PCB
18
to extend beyond the side of the IC
10
by a distance of at least A. In practice, a greater distance B will be required, since the copper contact pad
20
will not normally extend to the edge of the PCB
18
.
Another prior art approach includes mounting an IC in a manner which reduces the horizontal dimension from that of FIG.
1
. This prior art approach is illustrated in
FIG. 2
, in which like parts are denoted by like reference numerals. Here, the IC
10
and the PCB
18
are of the same horizontal extent. The contact
12
is positioned only on the underside
16
of the IC
10
, and the copper contact pad
20
extends to the edge of the PCB
18
. The connection is made by a solder body
22
′ which has only a planar portion. The solder fillet is lost, which degrades the mechanical strength and reliability of the connection, and may provide a poorer electrical connection.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method of mounting electronic components which facilitates minimization of the size of a device.
This and other objects, features, and advantages in accordance with the present invention are provided by a method of mounting an electronic component having at least one contact extending across a part of its undersurface. The method may include providing a support smaller in area than the undersurface of the component and having a contact pad for connection to the contact. The contact pad may have a first portion extending across an upper surface of the support adjacent one edge and a second portion extending from the edge across a side surface of the support. The method may also include positioning the electronic component and the support with the undersurface of the component adjacent the upper surface of the support. This is done so that the first portion of the contact pad is aligned with and spaced apart from a first portion of the contact, and the second portion of the contact pad is aligned with and disposed inwardly of a second portion of the contact.
The method may further include forming a solder connection between the contact and the contact pad. More specifically, the solder connection may include a planar portion between the first portions of the contact and the contact pad and a fillet portion extending angularly from the second portion of the contact to the second portion of the contact pad. The method thus provides for the combination of an integrated circuit and a printed circuit board in which the printed circuit board has an area smaller than an area of the integrated circuit.
REFERENCES:
patent: 4790894 (1988-12-01), Homma et al.
patent: 4839716 (1989-06-01), Butt
patent: 5369551 (1994-11-01), Gore et al.
patent: 5532910 (1996-07-01), Suzuki et al.
patent: 5838070 (1998-11-01), Naruse et al.
patent: 6064114 (2000-05-01), Higgins, III
patent: 6372985 (2002-04-01), Shimoe
patent: 3730497 (1989-03-01), None
patent: 0180730 (1986-05-01), None
patent: 0659032 (1995-06-01), None
patent: 0712266 (1996-05-01), None
Patent Abstracts of Japan, vol. 018, No. 326 (E-1565), Jun. 21, 1994 & JP 06 077631 A (Matsushita Electric Ind Co Ltd), Mar. 18, 1994.
Patent Abstracts of Japan, vol. 1995, No. 07, Aug. 31, 1995 & JP 07 111380 A (Murata Mfg Co Ltd), Apr. 25, 1995.
Patent Abstracts of Japan, vol. 1996, No. 12, Dec. 26, 1996 & JP 08 204328 A (Mitsubishi Electric Corp), Aug. 9, 1996.
Allen Dyer Doppelt Milbrath & Gilchrist, P.A.
Jorgenson Lisa K.
Nguyen Donghai D.
STMicroelectronics Ltd.
Vo Peter
LandOfFree
Method of mounting an electrical component to a support does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of mounting an electrical component to a support, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of mounting an electrical component to a support will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3191454