U.S. patent application number 12/236756 was filed with the patent office on 2009-01-22 for punched adhesive tape for semicconductor, method of manufacturing lead frame with the adhesive tape, lead frame with the adhesive tape, and semiconductor device comprising the lead frame.
Invention is credited to Youichi Hosokawa, Shinji Iioka, Hiroshi Kirihara, Yoshihiro Nomura, Yoshiyuki Tanabe, Satoru Yanagisawa.
Application Number | 20090022893 12/236756 |
Document ID | / |
Family ID | 16311261 |
Filed Date | 2009-01-22 |
United States Patent
Application |
20090022893 |
Kind Code |
A1 |
Tanabe; Yoshiyuki ; et
al. |
January 22, 2009 |
PUNCHED ADHESIVE TAPE FOR SEMICCONDUCTOR, METHOD OF MANUFACTURING
LEAD FRAME WITH THE ADHESIVE TAPE, LEAD FRAME WITH THE ADHESIVE
TAPE, AND SEMICONDUCTOR DEVICE COMPRISING THE LEAD FRAME
Abstract
A punched adhesive tape for semiconductor which is made by
punching an adhesive tape comprising a base film and an adhesive
layer provided on one or each side of the base film to mark the
regions in the adhesive tape where contaminants or defects are
contained; a method of producing an adhesive tape-bearing lead
frame by punching the punched adhesive tape for semiconductor, with
the parts containing the punched holes skipped over, and applying
the adhesive tape pieces punched out from the punched adhesive tape
for semiconductor to a lead frame; a semiconductor device
fabricated by using the adhesive-bearing lead frame.
Inventors: |
Tanabe; Yoshiyuki;
(Chiba-shi, JP) ; Nomura; Yoshihiro;
(Ichihara-shi, JP) ; Kirihara; Hiroshi;
(Ichihara-shi, JP) ; Hosokawa; Youichi;
(Ichihara-shi, JP) ; Iioka; Shinji; (Ichihara-shi,
JP) ; Yanagisawa; Satoru; (Ichihara-shi, JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET, SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
16311261 |
Appl. No.: |
12/236756 |
Filed: |
September 24, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11241992 |
Oct 4, 2005 |
7449076 |
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12236756 |
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10246620 |
Sep 19, 2002 |
7273654 |
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11241992 |
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09462943 |
Jan 18, 2000 |
6523446 |
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PCT/JP98/03072 |
Jul 9, 1998 |
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10246620 |
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Current U.S.
Class: |
427/289 |
Current CPC
Class: |
H01L 2924/00 20130101;
H01L 2924/00014 20130101; H01L 2224/83101 20130101; H01L 2224/32245
20130101; H01L 2924/00014 20130101; H01L 2924/00 20130101; H01L
2924/00012 20130101; H01L 2924/00 20130101; H01L 2224/4826
20130101; H01L 2924/00012 20130101; Y10T 156/1056 20150115; Y10T
428/2852 20150115; H01L 2224/4826 20130101; H01L 23/544 20130101;
H01L 2224/32245 20130101; Y10S 428/901 20130101; H01L 2924/01033
20130101; H01L 2924/181 20130101; H01L 23/4951 20130101; H01L
2224/73253 20130101; H01L 24/32 20130101; H01L 2224/83192 20130101;
H01L 2924/01077 20130101; H01L 2224/73215 20130101; H01L 2224/32245
20130101; Y10T 83/9416 20150401; H01L 2924/01075 20130101; Y10T
428/28 20150115; H01L 24/29 20130101; H01L 2224/45144 20130101;
Y10T 428/24273 20150115; Y10T 428/24322 20150115; H01L 2224/83192
20130101; Y10T 83/155 20150401; H01L 2223/54473 20130101; H01L
2924/01006 20130101; H01L 2924/01029 20130101; Y10T 83/543
20150401; H01L 24/27 20130101; Y10T 156/1062 20150115; H01L
2224/73215 20130101; H01L 2924/01027 20130101; H01L 2224/45144
20130101; H01L 2224/48091 20130101; H01L 2924/181 20130101; H01L
2224/83192 20130101; H01L 2224/32014 20130101; H01L 2924/181
20130101; Y10T 156/1084 20150115; H01L 2924/01079 20130101; H01L
24/45 20130101; H01L 24/48 20130101; H01L 2924/01005 20130101; H01L
2224/48091 20130101; H01L 2224/83856 20130101; H01L 2224/48247
20130101; H01L 2924/01082 20130101; H01L 2224/83101 20130101 |
Class at
Publication: |
427/289 |
International
Class: |
B05D 3/12 20060101
B05D003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 1997 |
JP |
9-193637 |
Claims
1. A method for making a punched adhesive tape for fabricating
semiconductor devices, comprising: providing an adhesive tape
comprising a base film and an adhesive layer provided on at least
one side of the base film; inspecting the adhesive tape for at
least one of contaminants and defects; punching at least one hole
completely through the base film and the adhesive layer at or in a
vicinity of a region at which a contaminant or a defect is
detected.
2. The method for making a punched adhesive tape for fabricating
semiconductor devices according to claim 1, further comprising
winding the adhesive tape having at least one hole punched
completely through the base film and the adhesive layer into a
roll.
3. The method for making a punched adhesive tape for fabricating
semiconductor devices according to claim 1, further comprising
winding the adhesive tape before inspecting the adhesive tape,
continuously unwinding the adhesive tape while inspecting the
adhesive tape, stopping the unwinding when a contaminant or a
defect is detected, and punching the at least one hole completely
through the base film and the adhesive layer at or in a vicinity of
a region at which a contaminant or a defect is detected while the
unwinding is stopped.
Description
[0001] This application is a Divisional Application of Ser. No.
10/246,620, filed Sep. 19, 2002, which is a Continuation
Application of application Ser. No. 09/462,943, filed Jan. 18,
2000, which is a national stage application filed under 35 USC 371
of International Patent Application (PCT) No. PCT/JP98/03072, filed
Jul. 9, 1998.
TECHNICAL FIELD
[0002] The present invention relates to punched adhesive tapes for
semiconductor particularly suitable for use in semiconductor
devices wherein semiconductor elements (chips) are bonded to lead
frames, and also relates to the production of adhesive tape-bearing
lead frames, to adhesive tape-bearing lead frames and to
semiconductor devices fabricated using the adhesive tape-bearing
lead frames.
BACKGROUND ART
[0003] In resin-molded semiconductor devices, adhesive tapes are
now mainly used as the adhesives for bonding semiconductor elements
(chips) to lead frames.
[0004] If the adhesive tapes used for the above purpose contain
contaminants or defects, the reliability of semiconductor devices
may be lowered. It is therefore necessary to inspect adhesive tapes
for contaminants and defects before applying the adhesive tapes to
adherend lead frames, to avoid using adhesive tapes containing
contaminants or defects.
[0005] A conventional, simple method of removing contaminants is to
cut off the parts containing contaminants from adhesive tapes, to
obtain contaminants free adhesive tapes. This method however
requires many hands and is inefficient.
[0006] According to an alternative for preventing contamination,
the regions containing contaminants are marked with seals, ink or
the like, to avoid these regions and use other regions for bonding.
This method also needs improvement since the adhesive tapes may be
contaminated by the marking, causing the contamination of adherend
chips.
DISCLOSURE OF INVENTION
[0007] The object of the present invention is to solve the above
problems and to provide an adhesive tape for semiconductor which is
excellent in work efficiency, a method of producing an adhesive
tape-bearing lead frame using the same, an adhesive tape-bearing
lead frame, and a semiconductor device fabricated by using the
same. As a result of study to prevent contamination without cutting
adhesive tapes nor contaminating them by marking with seals or ink,
we have hit upon an idea that punching adhesive tapes at or in the
vicinity of the regions containing contaminants or defects is
excellent in work efficiency and overcomes the above problems, and
we have consequently completed the present invention.
[0008] That is, the present invention provides a punched adhesive
tape for semiconductor, which is made of an adhesive tape
comprising a base film and an adhesive layer provided on one or
each side of the base film, and is pierced with at least one
punched hole which is made by punching the adhesive tape at or in
the vicinity of a region where the adhesive tape contains a
contaminant or a defect.
[0009] The punched adhesive tape for semiconductor of the present
invention is suitable particularly for bonding semiconductor chips
to lead frames, and also has various other uses in the fabrication
of semiconductor devices, for example, to bond semiconductor chips
to TAB tapes.
[0010] The present invention further provides a method of producing
an adhesive tape-bearing lead frame, comprising detecting the
punched hole in the punched adhesive tape for semiconductor,
punching the punched adhesive tape for semiconductor, with a part
thereof containing the punched hole skipped over, to punch out an
adhesive tape piece from the punched adhesive tape for
semiconductor, applying the adhesive tape piece to a lead frame,
with one adhesive layer of the adhesive tape piece adhering to the
lead frame.
[0011] The present invention further provides an adhesive
tape-bearing lead frame produced by the above-described method.
[0012] The present invention further provides a semiconductor
device fabricated by using the adhesive tape-bearing lead
frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a plan view of a punched adhesive tape for
semiconductor of an embodiment according to the present
invention.
[0014] FIG. 2 is an expanded cross-sectional view of the punched
adhesive tape for semiconductor as shown in FIG. 1 taken in the
direction of arrows A-A.
[0015] FIG. 3 is a cross-sectional view of a semiconductor device
of an embodiment according to the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0016] Hereinafter the punched adhesive tape for semiconductor of
the present invention and the adhesive tape-bearing lead frame
produced using the same will be described in detail.
[0017] Exemplary films usable as the base film in the present
invention include insulating heat resistant resin films, such as
polyimide films, polyether-amide films, polyether-amide-imide
films, polyether-sulfone films, polyether-ether-ketone films and
polycarbonate films. The base film is preferably transparent. The
thickness of the base film is preferably 5 to 200 .mu.m, more
preferably 25 to 50 .mu.m. Base films thicker than 200 .mu.m are
disadvantageous to the production of thin resin-molded
semiconductor devices, and base films thinner than 5 .mu.m may
lower the work efficiency in adhesive coating.
[0018] Non-limitative examples of adhesives usable to form the
adhesive layer of the punched adhesive tape for semiconductor of
the present invention include adhesives comprising thermoplastic
resins, such as aromatic polyamides, aromatic polyesters, aromatic
polyimides, aromatic polyethers, aromatic polyether-amide-imides,
aromatic polyester-imides and aromatic polyether-imides, and
adhesives comprising thermosetting resins, such as acrylic resins,
epoxy resins and phenolic resins.
[0019] The thickness of each adhesive layer of the punched adhesive
tape for semiconductor of the present invention is generally 1 to
100 .mu.m, preferably 5 to 50 .mu.m, more preferably 10 to 25
.mu.m.
[0020] For example, the adhesive tape to be used in the present
invention for the production of the punched adhesive tape for
semiconductor is produced by coating one or both sides of a base
film with a varnish of an adhesive dissolved in a solvent, and
heating the coating to dry by removing the solvent, to form an
adhesive layer on one or each side of the base film. Adhesives
comprising thermosetting resins are preferably semi-cured,
generally to B-stage, by the drying. The adhesive layer is
preferably transparent.
[0021] The adhesive tape may be provided with a peelable,
transparent protection film, such as polytetrafluoroethylene film,
polyethyleneterephthalate film, release-treated
polyethyleneterephthalate film, polyethylene film polypropylene
film or polymethylpentene film, on one or both adhesive layers.
Adhesive tapes provided with protection films may be punched
together with the protection films, or may be punched after the
protection films are peeled off. The thickness of the protection
film is preferably 5 to 100 .mu.m, more preferably 10 to 50
.mu.m.
[0022] The punching for making the punched holes piercing the
punched adhesive tape for semiconductor of the present invention
may be carried out by any method, for example by using a punching
machine comprising a tape-punching die and an air press capable of
reciprocating the die. Contaminants and defects contained in the
adhesive tape are removed by punching the adhesive tape at the
regions each containing a contaminant or a defect. However, it is
not always necessary to punch out each contaminant or defective
part completely so far as a region which contains a part of the
contaminant or defect or is close to the contaminant or defect is
punched out. Even in such cases, adhesive tape pieces free of
contaminants and defects can be obtained by punching the punched
adhesive tape for semiconductor, skipping over the punched holes
and the neighborhood. When a punched hole is made in the vicinity
of a region containing a contaminant or a defect, the distance
between the center of the punched hole and the region containing a
contaminant or a defect is preferably 10 cm or less, more
preferably 5 cm or less.
[0023] Herein, the term "contaminant" means a substance other than
the materials of the adhesive layer and of the base film, which
lowers the reliability of semiconductor devices, such as a fine
particle of a conductive substance and a dust particle, and the
term "defect" means the part lacking the adhesive layer, the part
where the thickness of the adhesive layer is not uniform, or the
like, which causes bonding failure.
[0024] The form of the punched hole is not limited, and is
preferably circular. The punched hole may be of any size which does
not cut the adhesive film. Preferred punched holes are circular
holes of 0.5 to 10 mm, more preferably 2 to 5 mm in diameter.
Punched holes having a diameter of more than 10 mm may lower the
tensile strength of the adhesive tape, causing break during
practical use. Punched holes of less than 0.5 mm in diameter are
difficult to make.
[0025] Punching adhesive tapes at the regions containing
contaminants or defects allows using long adhesive tapes as they
are since contaminants and defects can be removed without cutting
the adhesive tapes. A contamination inspection apparatus comprised
of an adhesive tape-unwinding part, a CCD camera (charge-coupled
device camera), a punching part and an adhesive tape-winding part
enables a continuous process comprising unwinding an adhesive tape
continuously from the adhesive tape-unwinding part, inspecting the
appearance of the fed adhesive tape with the CCD camera, slowing
down the adhesive tape to stop it upon the detection of a
contaminant or a defect, punching the region containing the
contaminant or defect to make a punched hole at the punching part,
resuming unwinding, and finally winding the punched adhesive
tape.
[0026] FIG. 1 is a plan view of a punched adhesive tape for
semiconductor of an embodiment according to the present invention,
and FIG. 2 is an expanded cross-sectional view of the punched
adhesive tape for semiconductor as shown in FIG. 1 taken in the
direction of arrows A-A. As shown in these figures, a punched
adhesive tape for semiconductor (1) consisting of a base film (2)
and two adhesive layers (3, 3) provided, respectively, on each side
of the base film (2) is pierced with a circular punched hole (4),
which is made by punching. The region of the material adhesive tape
where a contaminant or a defect was contained has been removed by
punching the punched hole (4).
[0027] According to the method of the present invention, an
adhesive tape-bearing lead frame is produced by detecting the
punched hole in the punched adhesive tape for semiconductor of the
present invention, punching the punched adhesive tape for
semiconductor, with a part thereof containing the punched hole
skipped over, to punch out an adhesive tape piece from the punched
adhesive tape for semiconductor, applying the adhesive tape piece
to a lead frame, with one adhesive layer of the adhesive tape piece
adhering to the lead frame.
[0028] The lead frame to be used in the method of the present
invention is not limited in structure, and examples of usable lead
frames include those for the use in COL (Chip on Lead) and LOC
(Lead on Chip) semiconductor devices. Exemplary materials of the
lead frame include 42 alloy and copper alloy. The lead frame
typically comprises inner leads, outer leads and bus bars, and one
or more adhesive tape pieces may be applied to any position
selected depending on the structure of the lead frame and on the
adherend, and when used to bond semiconductor chips, depending on
the shapes of the semiconductor chips, the pad array on the chips,
the design of the lead frame, etc.
[0029] The punched adhesive tape for semiconductor to be used in
this method preferably has an adhesive layer on each side of the
base film. When an adhesive film having only one adhesive layer is
used, an adhesive layer need be formed on the base film of the
adhesive tape piece applied on the lead frame, for example, by
coating an adhesive, to bond semiconductor chips thereon.
[0030] When the punched adhesive tape for semiconductor is provided
with one or two protection films, the protection film on the
adhesive layer which adheres to the lead frame need be peeled off
before punching. The protection film provided on the other side may
be peeled off either before punching, or after punching and
applying and before bonding adherend, such as semiconductor
chips.
[0031] The form of the adhesive tape piece punched out from the
punched adhesive tape for semiconductor depends on the structure of
the lead frame and on the adherend to be bonded to the lead frame.
For example, when the adherend is a semiconductor chip, the form of
the adhesive tape piece depends on the shape of the semiconductor
chip, the pad array on the semiconductor chip, the design of the
lead frame, or the like.
[0032] When the adhesive tape piece is applied to the lead frame,
the lead frame is generally heated to 150 to 450.degree. C. When
the adhesive layers are thermosetting adhesive layers, at least the
adhesive layer which does not contact the lead frame must not be
completely cured but need remain semi-cured. If completely cured,
the adhesive layer cannot bond adherend semiconductor chips any
longer.
[0033] Preferably, the method of the present invention for
producing an adhesive tape-bearing lead frame by using a punched
adhesive tape for semiconductor is carried out by employing a
common process for applying adhesive tapes to lead frames which
comprises unwinding an adhesive tape, punching the adhesive tape
(to punch out an adhesive tape piece to be applied to a lead
frame), applying the adhesive tape piece, and winding the punched
adhesive tape, and by adding thereto a step of detecting punched
holes prior to the punching of the adhesive tape piece. The
detection of punched holes can be carried out visually, but
preferably by using a CCD camera, which permits automatic detection
and improves the work efficiency.
[0034] By winding (skipping) the punched adhesive tape for
semiconductor a certain length, for example .+-.20 cm, preferably
.+-.10 cm from the center of each punched hole in the direction of
the length of the punched adhesive tape for semiconductor without
punching the regions containing the detected punched holes, it can
be prevented to apply adhesive tape pieces containing contaminants
or defects to lead frames. Further, since the regions of the
material adhesive tape where contaminants or defects are contained
are marked by punching, there is no fear of contaminating
semiconductor chips due to external causes, for example, due to the
marking of contaminants and defects with seals or ink. The method
of the present invention also reduces the work time since it
permits using long adhesive tapes as they are without cutting,
thereby reducing the number of the exchanges of adhesive tapes
during the work for applying adhesive tape pieces. That is,
according to the method of the present invention, adhesive
tape-bearing lead frames can be produced efficiently with good
yield.
[0035] The obtained adhesive tape-bearing lead frame has an
advantage of low production cost since the use of the punched
adhesive tape for semiconductor of the present invention improves
the work efficiency, yield and productivity in the production of
the adhesive tape-bearing lead frame. Also, the adhesive
tape-bearing lead frame can decrease defects in the semiconductor
devices produced using them, reducing the production cost.
[0036] The semiconductor device of the present invention has no
limitation in its structure so far as it is fabricated by using the
adhesive tape-bearing lead frame of the present invention. FIG. 3
is a cross-sectional view of a semiconductor device of an
embodiment according to the present invention, wherein the
semiconductor chip (7) is mounted on the lead frame (5) comprising
inner leads (51), outer leads (52) and bus bars (53). The inner
leads (51) are connected with the die pads of the semiconductor
chip (7) by, for example, gold wires (8). The semiconductor device
is molded with the sealing material (9). The semiconductor chip (7)
is bonded to the lead frame (5) by the adhesive tape piece (6) by
using an adhesive tape-bearing lead frame which consists of the
lead frame (5) and the adhesive tape piece (6) applied thereto.
[0037] For example, the semiconductor device of the present
invention is produced by bonding with heat and pressure a
semiconductor chip to the adhesive tape piece applied to the
adhesive tape-bearing lead frame of the present invention, curing
(C-stage) the adhesive layers when the adhesive layers are made of
thermosetting resin adhesives, connecting the inner leads of the
lead frame with the die pads of the semiconductor chip by wire
bonding, followed by molding with a sealing material, such as an
epoxy resin sealing material.
[0038] The present invention will be described in more detail with
reference to the following Examples, which, however, are not to be
construed to limit the scope of the invention.
EXAMPLE 1
[0039] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd., a three-layered adhesive tape: adhesive
layer 25 .mu.m thick (an aromatic polyether-amide-imide)/base film
50 .mu.m thick (a polyimide film)/adhesive layer 25 .mu.m thick (an
aromatic polyether-amide-imide)) 10 m long by 9 mm wide was
subjected to an appearance inspection using a contaminant (defect)
inspector (trade name: SCANTEC-5000, produced by Nagase Sangyo Co.,
Ltd.), which consists of an adhesive tape-unwinding part, a CCD
camera (trade name: TECEYE T15000H, produced by Excel Co., Ltd.), a
punching part and an adhesive tape-winding part. In the course of
the inspection, the contaminated or defective parts detected by the
CCD camera or the neighborhoods thereof were punched out (punched
hole: a circular hole of 3 mm in diameter) at the punching part.
Thus a punched adhesive tape for semiconductor 10 m long was
obtained without cutting the adhesive tape.
EXAMPLE 2
[0040] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd.) 50 m long by 9 mm wide was subjected to an
appearance inspection using a contaminant (defect) inspector
consisting of an adhesive tape-unwinding part, a CCD camera, a
punching part and an adhesive tape-winding part. In the course of
the inspection, the contaminated or defective parts detected by the
CCD camera or the neighborhoods thereof were punched out (punched
hole: a circular hole of 3 mm in diameter) at the punching part.
Thus a punched adhesive tape for semiconductor 50 m long was
obtained without cutting the adhesive tape.
EXAMPLE 3
[0041] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd.) 300 m long by 9 mm wide was subjected to an
appearance inspection using a contaminant (defect) inspector
consisting of an adhesive tape-unwinding part, a CCD camera, a
punching part and an adhesive tape-winding part. In the course of
the inspection, the contaminated or defective parts detected by the
CCD camera or the neighborhoods thereof were punched out (punched
hole: a circular hole of 3 mm in diameter) at the punching part.
Thus a punched adhesive tape for semiconductor 300 m long was
obtained without cutting the adhesive tape.
EXAMPLE 4
[0042] Using the punched adhesive tape for semiconductor produced
in Example 1, an adhesive tape-bearing lead frame was produced as
follows. A 42 alloy lead frame comprising inner leads, outer leads
and bus bars was used, and adhesive tape pieaces (1 mm.times.6 mm)
were applied to the inner leads and bus bars by a continuous
process comprising unwinding the adhesive tape, detecting punched
holes, punching out adhesive tape pieces, applying them to the lead
frame, and winding the adhesive tape, wherein the adhesive tape
pieces punched out from the adhesive tape for semiconductor were
applied to the lead frame by pressing them to the lead frame at
400.degree. C. for 3 seconds under a pressure of 3 MPa. The
detection of punched holes were carried out using a CCD camera, and
on detection of each punched hole, the adhesive tape was wound by
10 cm in the direction of length without punching, to avoid
punching a part of a length of .+-.5 cm from the center of the
punched hole in the direction of the length of the adhesive tape,
and to avoid applying the part to the lead frame. When all the
adhesive tape pieces which were applied in sequence to the lead
frame were inspected, no contaminants nor defects were
observed.
EXAMPLE 5
[0043] Semiconductor chips (6.6 mm.times.15 mm.times.0.28 mm) were
bonded to the adhesive tape-bearing lead frame produced in Example
4 on its side bearing the adhesive tape pieces by pressing for 3
seconds at 350.degree. C. under a pressure of 3 MPa. When the inner
leads and the semiconductor chips were connected by wire bonding,
no problem occurred. Then moldings with an epoxy resin sealing
material (Trade name: CEL-920, produced by Hitachi Chemical
Company, Ltd.) were carried out to produce semiconductor devices.
After a moisture absorption test for 168 hours at 85.degree. C. at
a relative humidity of 85% followed by a reflow test in an IR
furnace of a maximum temperature of 245.degree. C., all the
semiconductor devices worked properly without any malfunction.
COMPARATIVE EXAMPLE 1
[0044] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd.) of 10 m long by 9 mm wide was subjected to
an appearance inspection using a contaminant (defect) inspector
consisting of an adhesive tape-unwinding part, a CCD camera and an
adhesive tape-winding part. In the course of the inspection, each
time a contaminant or a defect was detected, the adhesive tape was
cut off to remove a part of 20 to 30 cm long containing the
contaminant or defect. Thus two adhesive tapes for semiconductor of
3 m and 6.7 m in length were obtained.
COMPARATIVE EXAMPLE 2
[0045] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd.) 50 m long by 9 mm wide was subjected to an
appearance inspection using a contaminant (defect) inspector
consisting of an adhesive tape-unwinding part, a CCD camera and an
adhesive tape-winding part. In the course of the inspection, each
time a contaminant or a defect was detected, the adhesive tape was
cut off to remove a part of 20 to 30 cm long containing the
contaminant or defect. Thus three 10 m-rolls, two 7 m-rolls and one
5 m-roll of adhesive tapes for semiconductor were obtained.
COMPARATIVE EXAMPLE 3
[0046] An adhesive tape (trade name: HM-122U, produced by Hitachi
Chemical Company, Ltd.) 300 m long by 9 mm wide was subjected to an
appearance inspection using a contaminant (defect) inspector
consisting of an adhesive tape-unwinding part, a CCD camera and a
tape winding part. In the course of the inspection, each time a
contaminant or a defect was detected, the adhesive tape was cut off
to remove a part of 20 to 30 cm long containing the contaminant or
defect. Thus three 50 m-rolls, four 20 m-rolls, five 7 m-rolls and
six 5 m-rolls of adhesive tapes for semiconductor were
obtained.
[0047] As to the adhesive tapes for semiconductor produced in
Examples 1 to 3 and Comparative Examples 1 to 3, the number of
punched holes, the length per roll, the total length, the
percentage of the tape loss upon applying them to lead frames, and
the number of exchanges of adhesive tapes during applying them to
lead frames are shown in Table 1.
TABLE-US-00001 TABLE 1 Number of Number of punched Tape loss
exchanges of holes Length/roll (%)*/roll adhesive tapes Example 1 1
10 m 15 once/10 m Comp. 0 3 m (1 roll) 50 twice/10 m Example 1 6.7
m (1 roll) 22 Total: 9.7 m Example 2 5 50 m 3 once/50 m Comp. 0 10
m (3 rolls) 15 six times/50 m Example 2 7 m (2 rolls) 21 5 m (1
roll) 30 Total: 49 m Example 3 17 300 m 0.5 once/300 m Comp. 0 50 m
(3 rolls) 3 18 times/300 m Example 3 20 m (4 rolls) 7.5 7 m (5
rolls) 21 5 m (6 rolls) 30 Total: 295 m *A tape loss of 1.5 m/roll
in total of the lengths from both ends of each adhesive tape was
caused by setting the adhesive tape to the production
apparatus.
[0048] Table 1 clearly shows that making punched holes in a
material adhesive tape permits using an adhesive tape in good yield
and improves work efficiency, compared with cutting the material
adhesive tape.
INDUSTRIAL APPLICABILITY
[0049] Because the punched adhesive tape for semiconductor of the
present invention is having contaminants and defects marked by
punching, detecting the punched holes can prevent such defective
parts of the adhesive tape from being applied to lead frames. Also
there is no external factors of chip contamination, which are
inherent in the conventional method of marking contaminants and
defects with seals or ink. Further, the punched adhesive tape for
semiconductor reduces the work time since it enables using long
adhesive tapes as they are without cutting, thereby decreasing the
number of the exchanges of adhesive tapes during the work for
applying adhesive tapes. That is, by using the punched adhesive
tape for semiconductor of the present invention, adhesive tape
pieces can be applied to lead frames with high work efficiency and
good yield.
[0050] Also the cost of producing the adhesive tape-bearing lead
frame of the present invention using the punched adhesive tape for
semiconductor is advantageously low since the adhesive tape-bearing
lead frame can be produced efficiently with good yield and high
productivity. Further, the adhesive tape-bearing lead frame reduces
the malfunction of the semiconductor devices fabricated by using
it, thereby lowering the production cost.
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