Packaged electronic component and method of preparing the same

A packaged electronic component includes an insulating body completely enclosing the electronic component except for runner-like blade leads which extend outwardly from the insulating body. The runner-like blade leads are more durable than conventional shaped leads and facilitate the making and breaking of sliding electrical contact with stationary contacts. A method of preparing the novel, packaged electronic component is also disclosed.

The field of the invention is electronic components, and, more 
particularly, packaged electronic components and a method of preparing the 
same. 
BACKGROUND OF THE INVENTION 
The successful development of reliable electronic components and circuits 
and the desire for increased security has created an interest in the 
development of identification systems which employ user carried devices 
such as cards and the like to gain access to otherwise secure information, 
equipment and/or locations. 
In one proposed identification system, the user carried device includes a 
miniature fixed value resistor and sensor means for determining if the 
resistor has the proper value. The miniature resistor in the user carried 
device has leads which make sliding electrical contact with stationary 
contacts of the identification system when the carrier device is inserted 
into an appropriate opening. Access is permitted if the resistor has the 
correct value and denied if it has the wrong value. For such application 
and other applications, there is a need for small packaged electronic 
components such as fixed value resistors, which have durable leads which 
can operate for thousands of cycles and which are an integral part of the 
packaged component. 
There is also a need in other applications for very small fixed value 
resistors especially those with a length/width aspect ratio of 1 or less. 
The standard physical sizes of resistors which have been established are 
primarily based on or determined by the maximum power rating of the given 
device and the basic technology used in its manufacture. As a result, most 
of the commonly available resistors are based on a cylindrical geometry 
with axial leads in which the length/width aspect ratio is greater than 1. 
This symmetrical geometry is used because of the symmetry considerations 
and to maximize the electrical length of the resist filament. 
In the past, it has been difficult to commercially manufacture very small 
packaged resistors or resistors having small lenght/width aspect ratio 
using known resistor preparation technology such as carbon composition, 
carbon film, metal film or metal glaze in the symmetrical geometry. The 
commonly used resistor preparation technologies can easily be adapted to 
make resistors larger than those which are normally encountered. However, 
problems are encountered when one tries to make very small resistors with 
a length/width aspect ratio which is less than 1 or with unusual lead or 
terminal configurations. 
SUMMARY OF THE INVENTION 
The present invention relates to small, novel, packaged electronic 
components, such as fixed value resistors, which are especially adapted 
for use in electronic systems in which the leads of the electronic 
component must be durable so as to repeatedly make effective sliding 
electrical contact with stationary contacts of the system. The invention 
also relates to a method of preparing small packaged electronic 
components, including fixed value resistors, which have a lenght/width 
aspect ratio of 1 or less. 
The novel packaged electronic component of the present invention includes 
an insulating body completely enclosing an electronic component or chip 
except for runner-like blade leads which extend outwardly from the 
insulating body. The runner-like blade leads are more durable than 
conventional leads and are shaped to facilitate the making and breaking of 
sliding electrical contact with stationary contacts. 
In a preferred embodiment the insulating body is formed of a deformable 
plastic so that the electronic component can be staked into an opening in 
a carrier device. 
The inventive method of the present invention includes providing a 
conducting support member of flat sheet metal and removing portions of the 
sheet metal of said member to form an opening and a pair of integral 
spaced apart fingers which extend into the opening. The fingers are 
connected at one end to the conducting member, and their free ends or tips 
have integrally formed termination pads. The method further includes 
attaching and electrically connecting an electronic chip to said 
termination pads, forming a package of insulating material enclosing the 
fingers, termination pads and electronic chip, curing the insulating 
material, if necessary, and then trimming the sheet metal of the 
conductive support member to form the leads and free the packaged 
electronic component from the support member. 
The method of the present invention is unique in that in the normal method 
of preparing a packaged electronic component, the conventional long, 
narrow leads are first formed on a lead frame carrier. The leads are then 
connected to the component, the packaging completed and the leads cut free 
from the carrier. In contrast, in the method of the present invention, the 
runner-like leads are formed after the packaging of the component is 
complete by trimming away the conductive sheet metal support member from 
which the inwardly directed fingers and termination pads were formed. 
It is an object of the present invention to provide a packaged, 
miniaturized electronic component which has broad outwardly extending 
runner-like blade leads which are especially adapted for repeatedly making 
sliding electrical contact with stationary contacts. 
It is another object of the invention to provide a method of preparing a 
novel, packaged electronic component with unconventional shaped leads. 
It is further object of the invention to provide and disclose a method of 
preparing an electronic component such as a fixed value resistor which has 
a length/width aspect ratio of 1 or less. 
The foregoing and other objects and advantages of the invention will appear 
from the following description. In the description, reference is made to 
the accompanying drawings which form a part hereof, and in which there is 
shown by way of illustration and not of limitation preferred embodiments 
of the invention. Such embodiments do not represent the full scope of the 
invention, but rather the invention may be employed in a variety of forms, 
and reference is made to the claims herein for determining the breadth of 
the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIGS. 1 and 2 of the drawings, the packaged electronic component 10 can 
be seen to include an insulating body 11 having a pair of runner-like 
leads 12,12'. As seen in FIG. 2, an electronic chip 13 is electrically 
connected by its terminals 13a and 13b to termination pads 14,14'. Each 
termination pad 14,14' is connected to its own finger 15,15' which is in 
turn connected to a separate runner-like lead 12,12'. The runner-like 
leads 12,12' are preferably tapered from their apex 12a,12a' toward each 
end to facilitate the easy making and breaking of sliding electrical 
contact with stationary contacts of an electrical system (not shown). 
The preferred method of preparing the packaged electronic component of 
FIGS. 1 and 2 will now be described in connection with FIGS. 3a to 3d. In 
FIG. 3a is seen an electrically conductive sheet metal support member 16, 
which has been die cut to remove a portion of the sheet metal and to form 
an opening 17, the fingers 15,15' which extend into the opening 17 and the 
termination pads 14,14'. 
In the next step of the method, each of the terminals 13a,13b of chip 13 is 
then attached and electrically connected to a respective termination pad 
14,14' by any standard bonding procedure such as soldering, welding or the 
use of conductive plastic adhesive of the like. The thus positioned chip 
13 is shown in FIG. 3b. 
When the electronic chip 13 has been properly attached to the termination 
pads 14,14' a split mold 18 having an upper piece 19 and a lower piece 20 
is positioned upon the support member 16. As seen in cross section in FIG. 
3c, a cavity 21 formed by the mold piece 19 and 20 and the support plate 
16 is filled with insulating material 22 to completely enclose the 
electronic chip 13, the termination pads 14,14' and the fingers 15,15'. 
Once the insulating material has cured, the mold 18 is split and removed 
leaving behind the insulating body 11 on the support member 16 as seen in 
FIG. 3d. The runner-like leads 12,12' are then formed by trimming the 
support member 16 along the dotted lines 23,23' shown in FIG. 3d to 
produce the packaged electronic component 10 seen in FIGS. 1 and 2. 
As can be seen in the drawings, the runner-like leads 12,12' are relatively 
broad and particularly configured for repeatedly making sliding contact 
with stationary contacts. In the preferred embodiment shown in the 
drawings, the runner-like leads 12,12' taper from the apex 12a,12a' in 
both directions to further facilitate the making and breaking of sliding 
electronic contact with the stationary contacts. 
Returning now to FIGS. 1 and 2, it can be seen that when the packaged 
electronic component 10 of the present invention is staked or otherwise 
secured within a carrier device 25 (shown in phantom lines) the 
runner-like leads 12,12' which are located near the center of the 
insulating body 11 do not extend to the mating surfaces of the insulating 
body 11 and the carrier device. As seen only in FIG. 2, the conductive 
runner-like leads 12,12' are spaced from edges of insulating body 11 by 
the gently curved portions 24,24' of the side walls of the insulating body 
11 thereby permitting the carrier device 25 to be made of metal or other 
conductive material. The curved portions 24,24' of the side walls of the 
insulating body also serve as lead-ins further facilitating the making and 
breaking of the sliding contact with stationary contacts. Obviously, if 
the carrier device 25 is made of an insulating material the leads 12,12' 
can extend the full length of the sidewall, if desired. 
The preferred insulating material is a deformable thermoplastic resin which 
flows easily at normal temperatures to fill the cavity 21 and which when 
hardened is deformable so that the packaged electronic component can be 
staked into an opening in a carrier device 25. Insulating materials having 
other desirable properties can also be employed, if desired. 
It will be apparent from the foregoing description that a novel and useful 
method has been disclosed for preparing packaged electronic components 
having runner-like leads. It will also be apparent to those skilled in the 
art that the method described in connection with the drawings FIGS. 3a to 
3d makes it possible to make small packaged resistors having a 
length-width aspect ratio of 1 or less as the length and width dimensions 
of the insulating body 11 can be varied to provide any desired aspect. As 
previously indicated, it has not been considered practical to make 
resistors having such small lenght/width aspect ratios by conventional 
methods. 
Although in the foregoing description the packaging of fixed value 
resistors has been discussed, it will be readily understood to those 
skilled in the art that other types of electronic components such as 
semi-conductors, etc., can be packaged in a similar manner. It will be 
further apparent to those skilled in the art that the method described 
makes it readily possible to prepare packaged electronic components with 
unusual shaped leads and that, therefore, the use of the method is not 
limited to making packages with runner-type leads. 
Those skilled in the art will recognize that variations can be made in the 
preferred embodiments of the invention without departing from the spirit 
thereof. For example, although a preferred embodiment has been shown in 
which the electronic component includes a single chip with a single pair 
of external leads it is to be understood that electronic components 
containing more than one chip and/or more than one pair of leads are 
intended to be within the scope of the invention. Furthermore, the terms 
used to describe the invention in the specification and claims should not 
be too narrowly interpreted. For example, the term "fingers" is intended 
to cover any shaped member which extends into the window or opening 17 and 
provides termination pads for connection to the electronic chip. 
Accordingly, the invention is not to be limited by the specific 
illustrated embodiments, but only by the scope of the appended claims.