Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead – Bump leads
Reexamination Certificate
2001-12-04
2004-11-16
Thomas, Tom (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
Bump leads
C257S666000, C257S698000, C257S778000, C257S781000
Reexamination Certificate
active
06818989
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a BGA (ball grid array) type semiconductor device using a TAB (tape automated bonding) tape or the like as an interposer between an LSI chip and an external terminal, a tape carrier for a semiconductor device, and a semiconductor device using said tape carrier. More particularly, the invention relates to a BGA type semiconductor device of the so-called “PSR via type” wherein an insulating film of a photosolder resist (PSR) has been provided on a side, where a wiring pattern is provided, while leaving via holes (PSR via) for solder balls, a tape carrier for a semiconductor device, and a semiconductor device using the same.
2. Prior Art
In recent years, in various types of equipment using semiconductor devices, including particularly portable equipment and mobile equipment, a reduction in size and a reduction in weight have been advanced. Therefore, regarding semiconductor devices used in these types of equipment as well, there is a demand for a reduction in size and a reduction in thickness. To meet this demand, in recent years, packages having substantially the same size as semiconductor elements, called “chip-size packages” (hereinafter abbreviated to “CSP”), have been proposed, and efforts have been made to commercialize semiconductor devices using these packages.
A BGA (ball grid array) type semiconductor device using a TAB tape as an interposer is shown as a representative example of these semiconductor devices in
FIGS. 1 and 2
.
This device is a BGA type semiconductor device of the so-called “PSR via type” wherein, while leaving via holes
12
for solder balls (PSR via), an insulating film
2
composed of a photosolder resist (PSR) is provided on a tape substrate
5
, composed of an insulating film, on its side where a wiring pattern
3
is provided.
Specifically,
FIGS. 1 and 2
show the construction of a conventional semiconductor device which is an object to be improved by the invention. A TAB tape
1
used in the semiconductor device comprises: a tape substrate
5
formed of a polyimide resin insulating film; a wiring pattern
3
which has been formed by bonding a copper foil onto one side of the tape substrate
5
through an adhesive
4
and photoetching the copper foil and has, on its one end, a bonding pad
10
for connection to a semiconductor and has, on its other end or in a portion between both ends thereof, a solder ball mounting pad
30
; and an insulating film
2
in a predetermined PSR pattern which has been formed, on the surface of the wiring pattern
3
in the region of the solder ball mounting pad
30
while leaving a via hole
12
for a solder ball, by printing a photosolder resist resin by means of a printing plate on the wiring pattern
3
and subjecting the print to pattern exposure and development.
In the TAB tape
1
as a wiring tape for mounting a semiconductor element, for wire bonding purposes, a window hole is generally formed in the center portion by stamping, and the insulating film
2
is not formed in the portion of the bonding pad
10
on the tape substrate
5
and a region extended inward from the bonding pad
10
.
In producing the semiconductor device, shown in
FIG. 1
, by using this TAB tape
1
, a semiconductor chip
7
is applied through an adhesive
6
onto the tape substrate
5
in its side remote from the wiring pattern
3
(opposite side of the tape substrate
5
), and an electrode
8
in the semiconductor chip
7
is electrically connected to the bonding pad
10
in the TAB tape through a bonding wire
9
formed of gold.
Next, the connection in the wire bonding, that is, the bonding lead portion, is sealed by a mold resin
11
. Thereafter, solder balls
13
formed by reflow treatment are mounted respectively on the solder ball mounting pads
30
in such a manner that the solder balls
13
are arrayed in via holes
12
for solder balls.
According to this semiconductor device, a wiring pattern
3
is provided on the tape substrate in its side opposite to the side on which the semiconductor chip
7
in its element formation surface is put. This construction permits the element electrode
8
in the semiconductor chip
7
to be bonded to the wiring pattern
3
through the bonding wire
9
which is passed through the window hole
15
. Therefore, the bonding wire
9
can be provided without being extended around the periphery of the semiconductor chip
7
. This can eliminate the need to ensure, on the periphery of the semiconductor chip
7
, a wiring space for the bonding wire
9
and thus can reduce the size and thickness of the whole device. Further, since wiring bonding can be carried out, a difference in coefficient of thermal expansion between the semiconductor element and the substrate can be absorbed by the bonding wire
9
. This is advantageous, for example, in that an inexpensive resin substrate rather than an expensive ceramic substrate can be used.
However, it has been found that, in sealing the bonding lead portion by the mold resin, the mold resin spreads on the PSR pattern and flows into the via hole (PSR via) for a solder ball and, consequently, the solder ball disadvantageously comes off from the via hole.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a BGA type semiconductor device which can solve the above problem of the prior art and can prevent the flow of a mold resin into a portion of a via hole for a solder ball through the provision of a groove.
It is another object of the invention to improve the effect of damming off a mold resin by a dam groove, which has been provided in such a form as not to expose the underlying wiring layer, and thus to improve the productivity of a tape carrier for a semiconductor device and a semiconductor device using the same.
According to the first feature of the invention, a BGA type semiconductor device comprises
a BGA type interposer comprising: a tape substrate formed of a resin insulating film; a wiring pattern, formed of a metal foil, provided on one side of the tape substrate; a bonding pad, for connection to a semiconductor, provided on one end of the wiring pattern; a solder ball mounting pad provided on the other end of the wiring pattern or in a portion between both ends of the wiring pattern; an insulating film provided on the surface of the wiring pattern in the region of the solder ball mounting pad while leaving a via hole for a solder ball; a window hole for wire bonding of the bonding pad to an electrode in a semiconductor element; and a groove portion which is a smaller-thickness portion of the insulating film provided in a part of the insulating film, for preventing the flow of a mold resin into the via hole for a solder ball,
a semiconductor element, provided with an electrode, mounted on the tape substrate, in the interposer, on its side remote from the wiring pattern, said electrode in the semiconductor element having been wire bonded to the bonding pad through the window hole, the connection between the bonding pad and the semiconductor element having been sealed with a mold resin by pouring the mold resin into the window hole while preventing the flow of the mold resin into the via hole for a solder ball by the groove portion, and
a solder ball mounted on the solder ball mounting pad.
According to this construction, by virtue of the provision of a groove portion, which is a smaller-thickness portion of the insulating film in a part of the insulating film, for preventing the flow of the mold resin into the via hole for a solder ball, in pouring the mold resin into the window hole used in wire bonding to perform sealing, even when the mold resin, which has been poured into the window hole, is likely to flow into the via hole for a solder ball, in which the solder ball mounting pad is present, from the window hole side, the mold resin first flows into the groove portion, whereby the flow of the mold resin into the via hole for a solder ball can be prevented by the groove portion. Therefore, the solder ball mounting pad is always maintained in an e
Ashizuka Norihiro
Higuchi Akifumi
Koizumi Toyoharu
Antonelli Terry Stout & Kraus LLP
Chu Chris
Hitachi Cable Ltd.
Thomas Tom
LandOfFree
BGA type semiconductor device, tape carrier for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with BGA type semiconductor device, tape carrier for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and BGA type semiconductor device, tape carrier for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3330831