Tape carrier including leads on both sides and resin-encapsulated semiconductor device incorporating the tape carrier

A tape carrier includes an electrically insulating carrier tape having a first tape surface to which a heat-dissipating metal cap is attached and a second tape surface opposite the first tape surface, a plurality of leads disposed on each of the tape surfaces and a surface area on the second tape surface free of leads for mounting a resin injection runner of a mold die directly on the tape. The present invention also includes a semiconductor device using the tape carrier and a method for manufacturing the semiconductor device.

BACKGROUND OF THE INVENTION 
This invention relates to a tape carrier and, more particularly, to a tape 
carrier for use in a molded Tape Carrier Package (T.C.P.) structure. This 
invention also relates to a semiconductor device on the tape carrier and a 
method of making the same. 
FIG. 5 is a sectional view illustrating a known tape carrier for use in a 
T.C.P. In FIG. 5, a tape carrier 5 comprises a carrier tape 1 made, for 
example, of polyimide, leads 2 disposed on the top surface of the carrier 
tape 1 and testing pads 3 disposed on the top surface of the carrier tape 
1 and electrically connected to one end of each of the leads 2 for use in 
testing. A resist 4 is disposed on the carrier tape 1 as well as on the 
lead 2. 
FIG. 6 is a top plan view of a known semiconductor device using the known 
tape carrier 5 illustrated in FIG. 5 but with the resin removed for 
clarity. As illustrated in FIG. 6, a plurality of the leads 2 are 
electrically connected at one end to the testing pads 3 and electrically 
connected at the other end to a semiconductor chip 6 and extend outwardly 
from each side of the semiconductor chip 6. Perforations 18 along both 
sides of the carrier tape 1 are at fixed intervals along straight lines. 
During manufacture and test, the carrier tape 1 is fed and held in place 
by a sproket wheel (not shown) engaging the perforations 18. 
The testing pads 3 are disposed close to the perforations 18 so that the 
testing pads 3 can be touched easily with, for example, a testing pin (not 
shown) during testing. Since the testing pads 3 have a width such as 0.7 
mm which is wide as compared with that of the leads 2 and the testing pads 
3 are disposed at very minute intervals such as about a few hundred .mu.m, 
it has been recently difficult to increase the number of the testing pads 
3 with an increase in the number of the leads 2. Further, as seen from 
FIG. 6, a hole 8 is disposed in the carrier tape 1 through which molten 
resin flows on the top side of the carrier tape 1 from the underside 
thereof when the semiconductor chip 6 is being molded together with the 
tape carrier 5 in a metal die. 
FIG. 7 is a sectional view taken along line 7--7 in FIG. 6 and illustrates 
one example of a known molding method. As seen from FIG. 7, the 
semiconductor chip 6 is mounted on a heat radiating metal cap 9. The 
semiconductor chip 6 is electrically connected to the leads 2 and the 
testing pads 3 through a bump 7 which is disposed on the semiconductor 
chip 6. The heat radiating metal cap 9 is a substantially dish-shaped 
member having a circumferential brim 9a at its edge which is attached to 
the bottom surface of the carrier tape 1 and an inside bottom to which the 
semiconductor chip 6 is attached. The tape carrier 5 and the semiconductor 
chip 6 as described above are clamped between mold dies for molding 
together with the heat radiating metal cap 9. The mold dies are composed 
of an upper die 10 and a lower die 11 which form a cavity 14 therebetween 
for accommodating the semiconductor chip 6, the tape carrier 5 and the 
heat radiating metal cap 9. Further, a first resin-supply runner 12 is 
provided in the lower die 11 to let the molten resin flow therethrough and 
a second resin-supply runner 13 is disposed in the upper die 10 which is 
connected to the first resin-supply runner 12 through the hole 8 in the 
carrier tape 1. The first runner 12 is placed at the position illustrated 
by a phantom line in FIG. 6. As illustrated in FIG. 7, disposed between 
the second runner 13 and the cavity 14 is a gate 15 through which the 
molten resin 16 flows into the cavity 14 from the second runner 13. 
If the mold resin 16, which is attached to the testing pads 3 and the leads 
2 which are disposed on the carrier tape 1 during molding, is cured and 
fixed on the testing pads 3 and the leads 2, the testing pads 3 and the 
leads 2 may be peeled off from the carrier tape 1 together with the resin 
16 during the gate-breaking process for removing the runners 12 and 13. 
Accordingly, in order to prevent the molten resin 16 from attaching to the 
testing pads 3 and the leads 2, the molten resin 16 may be caused to flow 
under the carrier tape 1 through the first runner 12 disposed in the lower 
die 11 and is injected into the cavity 14 in a manner known as the low 
pressure transfer molding method. However, as the molten resin 16 cannot 
be directly injected into the cavity 14 from the first runner 12 disposed 
under the carrier tape 1 because of the heat radiating metal cap 9, the 
hole 8 must be disposed in the carrier tape 1 upstream of the cavity 14 so 
that the molten resin 16 flows from the underside of the carrier tape 1 to 
the top side thereof through the hole 8 and injected into the cavity 14 
through the gate 15. 
If there is a portion 14a defined outside of the heat radiating metal cap 9 
within the cavity 14 and in which the mold resin 16 cannot be easily 
injected, a communication hole 9b may be disposed in the heat radiating 
metal cap 9. In the gate-breaking process for removing the resin 16 within 
the runners 12 and 13, firstly, the resin 16 within the gate 15 is snapped 
off by bending the carrier tape 1. Since the resin 16 within the first 
runner 12 is connected to the resin within the second runner 13 through 
the hole 8, the resin 16 within the second runner 13 is taken out from 
there through the hole 8 as the carrier tape 1 is being flexed. FIG. 8 
illustrates a conventional semiconductor device of the T.C.P. structure 
manufactured by the above-described method. 
In the known molding process as described above, the carrier tape 1 is 
clamped between the upper die 10 and the lower die 11. However, the 
carrier tape 1 cannot be clamped around the hole 8 as illustrated in FIG. 
9 since the second runner 12 is formed within the lower die 11. Therefore, 
these unclamped portions of the carrier tape 1 expand and sag loosely due 
to heat of the mold dies 10 and 11 and an undesirable gap 17 arises 
between the carrier tape 1 and the upper die 10 as well between the 
carrier tape 1 and the lower die 11. When the molten resin 16 is led from 
the first runner 12 to the second runner 13 through the communication hole 
8, the molten resin 16 undesirably enters into the gap 17. After molding, 
the cured mold resin 16 within the gap 17 remains attached to the leads 2 
and the testing pads 3 as undesirable burrs 19 illustrated in FIG. 8. 
Further, in the known semiconductor device, since the first and second 
runners 12 and 13, which are respectively disposed on the upper side and 
the underside of the carrier tape 1 and connected to each other through 
the communication hole 8 disposed in the carrier tape 1, must be provided 
in the metal dies 10 and 11, the structures of the metal dies 10 and 11 
are not simple and the gate-breaking process is not easy and not 
efficient. 
Still further, the undesirable burrs 19 hinder the removal of the 
unnecessary mold resin 16 within the runners 12 and 13 during the 
gate-breaking process and the unnecessary resin 16 as well as the burrs 19 
cannot be easily removed, resulting in a poor appearance and a poor 
formability. 
SUMMARY OF THE INVENTION 
Accordingly, one object of the present invention is to provide a tape 
carrier or a semiconductor device free from the above-discussed problems 
of the known tape carrier and the known semiconductor device. 
Another object of the present invention is to provide a tape carrier or a 
semiconductor device having an improved assembling operations, in 
particular, gate-breaking operation efficiency. 
Another object of the present invention is to provide a tape carrier or a 
semiconductor device which can be easily molded in metal dies which have 
simple structures. 
A further object of the present invention is to provide a tape carrier or a 
semiconductor device which prevent an undesirable burr from being 
generated. 
A still further object of the present invention is to provide a tape 
carrier or a semiconductor device having good lead formability. 
Another object of the present invention is to provide a tape carrier or a 
semiconductor device in which leads can be disposed on both surfaces of 
the carrier tape and which can accommodate a comparatively large number of 
leads and testing pads. 
With the above objects in view, a tape carrier according to the present 
invention comprises an electrically insulating carrier tape having two 
surfaces, a plurality of leads disposed on both of the surfaces of the 
carrier tape and a surface area defined on one of the tape surfaces. The 
surface area has no lead thereon and allows the resin injection runner of 
the mold die to be directly mounted thereon. 
A semiconductor device according to the present invention comprises an 
electrically insulating carrier tape having two surfaces, a plurality of 
leads disposed on both of the tape surfaces, a semiconductor chip 
electrically connected to the leads and disposed on heat-dissipating means 
for radiating heat from the semiconductor chip, a surface area defined on 
one of the tape surfaces and a resin hermetically sealing therein the 
semiconductor chip, the heat-dissipating means, the carrier tape and the 
leads. The surface area has no lead thereon and allows the resin injection 
runner of the mold die to be directly mounted thereon. 
The present invention also resides in a method for manufacturing a 
semiconductor device comprising the steps of preparing the tape carrier of 
the present invention as described above, electrically connecting the 
leads to a semiconductor chip disposed on heat-dissipating means, directly 
mounting a resin injection runner of a mold die on the surface of the tape 
carrier and mounting the semiconductor chip, the heat-dissipating means, 
the tape carrier and the leads in a molding die, filling the molding die 
with the molten resin through the resin injection runner of the mold die, 
curing the mold resin within the mold die to hermetically mold the 
semiconductor chip, the heat-dissipating means, the tape carrier and the 
leads, taking the semiconductor chip molded by the mold resin out of the 
die and cutting the semiconductor chip molded by the mold resin from the 
tape carriers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a sectional view illustrating an embodiment of a tape carrier 32 
of the present invention for use in a Tape Carrier Package (T.C.P.). As 
illustrated in FIG. 1, the tape carrier 32 of the present invention 
comprises an electrically insulating carrier tape 1 having two major 
surfaces and made, for example, of polyimide and a plurality of leads 30 
disposed on both of the major surfaces of the carrier tape 1. A plurality 
of testing pads 31 are also disposed on both of the major surfaces of the 
carrier tape 1 and each electrically connected to one end 30a of a 
corresponding lead 30. The other ends 30b of the leads 30 disposed on the 
top surface of the carrier tape 1 are curved gently and downwardly and the 
other ends 30b of the leads 30 disposed on the bottom surface of the 
carrier tape 1 are curved gently and upwardly so that the ends 30b of the 
leads on the top surface and on the bottom surface are in the same plane 
to be easily connected to a semiconductor chip 6. A resist 4 covers and is 
attached to all of both surfaces of the carrier tape 1 including on the 
leads 30. 
In FIG. 2, the carrier tape 1 is an elongated rectangular member and a 
plurality of the semiconductor chips 6 are disposed on the middle portion 
of the carrier tape 1 parallel to the side of the elongated carrier tape 1 
at regular intervals. A plurality of the leads 30, which are disposed on 
both surfaces of the carrier tape 1, are electrically connected to each 
side of the semiconductor chip 6. Therefore, the testing pads 31 and the 
semiconductor chip 6 are electrically connected to each other through the 
leads 30. Also, a plurality of perforations 18 are present along both 
sides of the carrier tape 1 at the fixed intervals along two straight 
lines. During manufacture, the carrier tape 1 is automatically fed and 
held in place by feeding means such as a sproket wheel (not shown) 
engaging the perforations 18. The testing pads 31 are disposed close to 
the perforations 18 so that the testing pads can be touched easily with a 
testing pin (not shown) during testing. 
In the semiconductor device of the present invention, as illustrated in 
FIG. 2, since the leads 30 and the testing pads 31 are disposed on both of 
the top and bottom surfaces of the carrier tape 1, therefore, less than 
half of the leads 30 and the testing pads 31 may disposed on the top 
surface and so there is room on the top surface as compared with the known 
semiconductor device in which all the leads 30 and the testing pads 31 are 
disposed only on the top surface as described above. A surface area 35a is 
established on the top surface of the carrier tape 1 for directly 
positioning thereon a resin injection runner 35 (See FIG. 3) of a metal 
die during molding as illustrated by the phantom line in FIG. 2. As the 
leads 30 and the testing pads 31 can be disposed on all of both surfaces 
of the carrier tape 1 except for the surface area 35a, the semiconductor 
device of the present invention can accommodate almost twice as many of 
the leads 30 and the testing pads 31 as that of the known semiconductor 
device. 
FIG. 3 is a sectional view taken along line 3--3 in FIG. 2 and illustrates 
a method of manufacturing the semiconductor device of the present 
invention. In FIG. 3, the tape carrier 32 illustrated in FIG. 1 is 
disposed on a lower die 33 of a metal dies for molding and clamped by the 
lower die 33 and an upper die 34 of the mold dies. Also, a heat-radiating 
metal cap 9 is disposed on the lower die 33. The radiating metal cap 9 is 
a substantially dish-shaped member having a circumferential brim 9a at its 
edge. The semiconductor chip 6 is disposed within the radiating metal cap 
9 and electrically connected to the leads 30 through a bump 7 which is 
disposed on the semiconductor chip 6. The circumferential brim 9a is 
attached to the bottom surface of the carrier tape 1 while the resist 4 
prevents electrical short-circuiting therebetween. The resin injection 
runner 35 is disposed in the upper die 34 for introducing a molten resin 
16 therethrough. The upper die 34 and the lower die 33 together form a 
mold cavity 36 therein accommodates the semiconductor chip 6 and the heat 
radiating metal cap 9. The runner 35 and the cavity 36 are connected to 
each other through a gate 37. 
During molding, the molten resin 16 is introduced through the runner 35 on 
the top surface of the carrier tape 1. Since there are no leads 30 and no 
testing pads 31 in the runner 35, the molten resin 16 does not attach to 
the leads 30 and the testing pads 31. The molten resin 16 is led only on 
the top surface of the carrier tape 1 and injected into the cavity 36 from 
the runner 35 through the gate 37. In the semiconductor device of the 
present invention, as the carrier tape 1 can be clamped tightly by the 
upper and lower dies 34, 33 and there is no slack of the carrier tape 1 
caused by thermal expansion of the carrier tape 1, an undesirable burr is 
prevented from being generated. 
If there is a portion 36a disposed outside of the radiating metal cap 9 in 
the cavity 36 and the molten resin 16 cannot easily flow into the portion 
36a, the through hole 9a may be disposed, if necessary, in the radiating 
metal cap 9. 
In the semiconductor device of the present invention, all that is required 
in the gate-breaking process is that the resin 16 within the gate 37 be 
snapped off by bending the carrier tape 1 so that the unnecessary mold 
resin 16 within the runner 35 is taken off the carrier tape 1. Hence ends 
of the leads 30 and the testing pads 31 are exposed outside as illustrated 
in FIG. 4. 
As has been described, a tape carrier and a semiconductor device according 
to the present invention the leads 30 and the testing pads 31 are disposed 
on both surfaces of the carrier tape 1 so there is room on the top surface 
of the carrier tape 1 to dispose the surface area 35a for directly 
mounting the resin injection runner 35 of the metal die thereon. Further, 
during molding, the carrier tape 1 can be clamped tightly without slack in 
metal dies which have simple structures. The molten resin 16 can flow only 
on the top surface of the carrier tape 1 and no undesirable burr is 
generated resulting in an excellent appearance and good lead formability. 
Also, in the gate-breaking process, the unnecessary resin 16 within the 
runner 35 can be removed easily and with a good appearance only by 
snapping off the mold resin 16 within the gate 37. 
Still further, in the tape carrier and the semiconductor device of the 
present invention, as the leads 30 and the testing pads 31 can be disposed 
on the both surfaces of the carrier tape 1, a large number of the leads 30 
and the testing pads 31, almost twice as many as those of the known tape 
carrier and the known semiconductor device as described above, can be 
accommodated.