Note: Descriptions are shown in the official language in which they were submitted.
:
13132q8
METHOD OF MAKING A HERMETICALLY SEALED
PACKAGE HAVING AN ELE~TRONIC CQMPONENT
Background of the Invention
It is known to hermetically seal an electronic
component in a package for protecting the component from
environmental conditions. However, it is desirable to
provide a package and a method of manufacture using tape
automated bonding (TAB) leads for providing a less
expensive method of manufacture. Another purpose of the
present invention is to provide such a package that will
satisfy current military specifications. That is,
specifications require that the electronic component or
die use an eutectic die attachment method in hermetic
packages. However, presently tape automated bonding leads
are not compatible with eutectic die attachment method
because the presence of the tab leads makes it difficult
to grip the die adequately to perform the necessary
scrubbing and attachment action. Furthermore when using
an eutectic die attachment, the accuracy necessary or
outer lead alignment with the die cannot be achieved.
:
. -
~ 2- 1 3 1 3298
1 Summary
~ he present invention is directed to a
hermetically sealed package having an electronic component
which allows the use of tape automated bonding leads for
providing a less expensive manufacturing process. In
addition, the method of making the present package allows
the use of eutectic die attachment methods with tape
automated bonding leads and further provides a better
eutectic die attachment method by bonding the die to a
metal plate which has better conductivity than a ceramic
body.
A still further object of the present invention
is the provision of a hermetically sealed package having
an electronic component therein including a body of
insulating material in which the body has an opening
therethrough. A plurality of electric conductors are
provided in the body extending from adjacent the opening
to points on the exterior of the body outside of the
opening for making electrical connections to the sealed
package. Top and bottom covers are connected to the body
enclosing and sealing the openlng from the outside
environment. An electronic component is bonded to the
bottom cover and positioned in the body opening adjacent
the electrical conductors and a plurality of tape
automated bonding leads are provided in the opening having
outer ends bonded to the electrical conductors and having
inner ends bonded to the electronic component. Preferably
the covers are metal and preferably a metal seal is
provided between the body and the covers. If desired to
meet military specifications, the electronic component is
eutectically bonded by heat to the top o~ the bottom metal
cover by gold.
Still a further object of the present invention
is wherein the body includes an upper facing shelf in the
body about the opening supporting one of the ends of the
''' :
.. - `-
~ .
~3~ 1 31 32q8
1 electrical conductors for engagement with and bonding to
the outer ends of the leads.
A further object of the present invention is the
provision of a method of making a hermetically sealed
package having an electronic component therein which
includes forming a body of insulating material with an
opening therethrough and a plurality of electrical
conductors in the body extending from adjacent the opening
through the body to points on the exterior of the body
outside of the opening. The method includes placing a
plurality of electrical leads having inner and outer ends
in the opening in which the inner ends of the leads are
connected together for aligning the leads with each
other. Ne~t, the outer ends of the plurality of leads are
aligned in contact with the electrical conductors adjacent
the opening and each of the outer ends of each o the
leads is bonded with one of the electrical conductors.
Thereafter, the inner ends of the leads are disconnected
from each other. An electronic component is bonded to the
top of a bottom cover and placed in the opening and
aligned and bonded to the inner ends of the electrical
leads. Thereafter, the bottom cover is sealed to the
bottom of the body and a top cover is sealed to the top o
the body for enclosing the opening.
The electrical leads are formed from tape
automated bonding tape. Preferably the covers are metal
and are sealed to a metal seal on the body. If it is
desired to meet military specifications, the electronic
component is eutectically bonded by heat -to -the top of a
bottom metal cover with gold. Preferably the body
includes a shelf surrounding the opening from which the
electrical conductors extend and which receives a
plurality of tape automated bonding leads' outer ends for
aligning with and are bonded to thz electrical
conductors.
-4-- l 31 3298
1 Other and further objects, features and
advantages will be apparent from the following description
of a presently preferred embodiment of the invention given
for the purpose of disclosure and taken in conjunction
with the accon,panying drawings.
Brief Description of the Drawinq~
Fig. l is an elevational view of the body of the
package of the present invention,
Fig. 2 is a perspective view, in cross section of
the body of Fig. l,
Fig. 3 is a fragmentary perspective view of the
step of punching out and placing a tape automated bonding
tape lead support in the body,
Fig. 4 is a fragmentary perspective view
illustrating the step of bonding the outer leads to the
electrical conductors in the body,
Fig. 5 is a fragmentary perspective view
illustrating separating the inner leads from each other by
a punch,
Fig. 6 is a fragmentary perspective view
illustrating the step of attaching the electronic
component or die to a cover,
Fig. 7 is a fragmentary perspective view
; 25 illustrating the step of aligning th~ electronic component
or die with the inner ends of the leads and bonding
thereto, and
Fig. 8 is a fragmentary perspective view
illustrating the step of sealing the top and bottom covers
to the body.
Description of the Preferred Embodimçnt
ReEerring now the drawings and particularly to
Figs. l and 2, the reference numeral l0 shows the body in
which an electronic component is to be hermetically
..
~`' _5~ 1 31 3298
1 sealed. The body 10 is made of any suitable insulating
material such as ceramic which may be aluminum oxide and
includes an opening 12 therethrough. Preferably the body
includes a shelf 14 surrounding the opening 12. A
plurality of electrical conductors 16 e~tend from adjacent
the opening 12 by being positioned on the top of the shelf
14 for interconnection with an electric component as will
be more fully described hereinafter and extend to the
exterior of the body to contact points 1~ for connection
with other electrical apparatus. ~or ease of
illustration, the number of leads is shown as twelve,
although any desired number may be provided. Preferably a
top metal seal 20 is provided around the opening 1~ and a
bottom metal seal (not shown~ is provided on the bottom of
the body 10.
Referring now to Fig. 3, a tape-automated bonding
(TAB) tape 22 is provided for providing a plurality of
leads for interconnecting an electronic component to the
electrical conductors 16. Thus, a plurality of frames are
provided on the tape 22 to provide a plurality of tape
lead supports 24. Each of the lead suppor~s 24 include a
plurality of leads 26. Each of the leads 26 includes an
outer end 28 and an inner end 30. The inner ends 30 are
connected together by a support 32 for keeping the leads
26 properly aligned with each other for holding them in
position while bonding them to the electrical conductors
16. As best seen in Fig. 3, a punch 34 punches a lead
support 24 out of the tape 22 and the lead support 24 is
placed in the body 10 in the opening 12. As best seen in
30 Fig. 4, the spyder 24 is in position in the body 10 and
positioned on shelf 14. An alignment pedestal 36 moves
into the bottom of the opening 12 for aligning the outer
ends 28 of the spyder 24 with the electrical conductors 16
on the shelf 14. With the leads 26 properly aligned,
conventional bonding of the outer ends 28 to the
~ 3 1 3298
1 electrical conductors 16 may be conventionally
accomplished such as by thermocompression welding by a
bonder 38.
Referring now to Fig. 5, a punch 40 punches out
the support 32 as the leads 26 are now properly posi-tioned
by being bonded to the electrical conductors lfi. That is, :
as best seen in Fig. 7, the electrical leads 26 have their
outer ends 28 bonded and their inner ends 30 extending
over and into the opening 12 for being bonded to an
electrical component 50.
Referring now to Fig. 6, an electri.cal componen-t
50, such as a silicon integrated circuit or die, is bonded
to a bottom cover 52. Preferably the bottom cover 52 is a
metal plate such as ~lloy 42 or Kovar. While the die S0
may be bonded to the cover bottom 52 by any suitable
means, in order to meet military specificatioris, the die
50 is attached by the eutectic attachment method in which
a plating of gold is provided between the die 50 and the
bottom cover 52. The bonding is accomplished by heating
20 the bottom cover 52 by a heater 53 and a scrub collet 56
grips the die 50 and scrubs it across the top surface o~
the cover 52 for making the necessary bond.
After the die 50 is bonded to the bottom cover
52, the die 50, as best seen in Fig. 7, is inserted into
the bottom of the opening in the body 12 for aligning the
electrical pads 54 on the die 50 with the inner ends 30 of
th0 TAB leads Z6. This is accomplished with the aid of an
alignment pedestal 58 engaging and moving the bottom cover
5~. With the pads 54 in alignment with the inner ends 30,
the inner ends 30 are bonded to the pads 54 by any
suitable conventional means such as a thermode 56 whi~h
simultaneously bonds all of the ends 30 to the pads 54~
As best seen in Fig. 8, the bottom cover 52 is
sealed to the body lO and a top cover 60 is sealed to the
top of the body lO thereby enclosing the opening and the
.
, ,,
~ 1 31 3298
1 elec~ronic component 50 therein in a hermetical seal. The
sealing may be done by heating and securing the plates to
the metal seals 20 or by welding. Thereafter, the
complete package may be interconnected to other electrical
components by means of the point contacts 18.
The present hermetically sealed package and
method of making is particularly advantageous in using TAB
leads for making the interconnection between the body lO
and the electronic component 50. This is accomplished by
using the lead support 24 and bonding the outer ends 28 to
the body lO leaving the inner ends 30 aligned and in
position for being bonded to the electronic component 50.
Since the electronic component or die 50 is much more
expensive than the body 10 and lead support 24, these
components may be inexpensively discarded in the event
that the combination of the leads 26 and body 10 are
manufactured with defects without having to discard the
more expensive electronic component 50. The method of
manufacture is also advantageous in providing a way of
accurately aligning the padl~ 54 of the die 50 with the
inner ends 30 of the leads 26. That is, when the die 50
is bonded to the bottom cover 52, as best seen in Fig. 6,
the positional accuracy of the placement of the die 50 on
the cover 52 is not always repeatable. That is,
eutectically bonding the die 50 cannot be perEormed with
repeatable accuracy for alignment with the outer ends 30
because the die 50 may set and bond at slightly difEerent
positions on the plate 52. However, because the plate 52
is movable relative to the body lO, the plate 52 can be
moved in the step of the process shown in Fig. 7 on the
alignment pedestal 58 for accurately aligning the pads 54
with the inner ends 30 of the leads 26. Another advantage
of the present process is that the bottom cover 52 is
metal which has a good heat conductivity for more quickly
131329~
and easily performing the bonding of the die ~0 to the
cover 52 in the step of Fig. 6.
The method of the present invention is apparent
from the d~scription of the presently pre~erred embodiment
and includes forming a body of an insulating material with
an opening therethrough and an upwardly directed shelf in
the body surrounding the opening. A plurality of
electrical conductors extend from the top of the shelf to
the exterior of the body outside of the opening. The
method includes placing a plurality of tape automated
bonding leads in the opening in which th leads have inner
and outer ends and the inner ends are interconnected
together by a support for aligning the leads with each
other. The outer ends of the leads are aligned in contact
with the electrical conductors on the shelf and each of
the outer ends are then bonded with one of the electrical
conductors. The support is removed from the inner ends of
the leads thereby disconnecting the inner ends. An
electronic component is bonded by heat to the top of a
bottom layer and aligned in the opening adjacent the ends
of the leads and bonded thereto. The bottom cover and a
top cover are sealed to the body enclosing the opening
providing a hermetic seal for the electronic ~omponent.
The present invention, therefore, is well adapted
to carry out the objects and attain the ends and
advantages mentioned as well as others inherent therein.
While a presently preferred embodiment of the invention
has been given for the purpose of disclosure, numerous
changes in the details of construction, arrangement of
parts, and steps of the process will be readily apparent
to those skilled in the art and which are encompassed in
the spirit of the invention and the scope of the appended
claims.
: ,' ' : '
.
