United States Patent (19)
`Shibata et al.
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`USOO5762744A
`Patent Number:
`11
`45 Date of Patent:
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`5,762,744
`Jun. 9, 1998
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`METHOD OF PRODUCING A
`SEMCONDUCTOR DEVICE USENG AN
`EXPAND TAPE
`
`Inventors: Kazutaka Shibata; Yutaka Murakami,
`both of Kyoto, Japan
`Assignee: Rohm Co., Ltd., Kyoto. Japan
`
`Appl. No.: 870,643
`Filed:
`Jun. 6, 1997
`Related U.S. Application Data
`
`Continuation of Ser. No. 200290, Feb. 22, 1994, abandoned,
`which is a division of Ser. No. 816,398, Dec. 27, 1991, Pat.
`No. 5,316,853.
`Int. Cl. ........... B32B 3/12: B32B 31/18;
`HO1L 21/OO
`U.S. C. ......................... 156/235; 156/344; 156/584;
`437,266
`Field of Search ..................................... 156/235,344,
`156/584; 437/266
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`54
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`75
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`73
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`21
`22
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`60
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`51
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`52)
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`4,720,317
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`References Cited
`U.S. PATENT DOCUMENTS
`1/1988 Kuroda et al. .......................... 156,250
`
`
`
`4,961.804 10/1990 Aurichio ................................. 156/248
`5,030,308
`7/1991. Sheyonet al. ...
`... 156,235
`5, 10,388 5/1992 Komiyama et al. .................... 156/229
`5,275,958
`1/1994 Ishikawa ................................. 437/226
`5,476,565 12/1995 Akada et al. ........................... 156/235
`FOREIGN PATENT DOCUMENTS
`0107563 8/1981 Japan.
`54-188940 10/1984 Japan.
`3-152942 6/1991 Japan.
`403286 12/1991 Japan.
`Primary Examiner-David A. Simmons
`Assistant Examiner-Linda L. Gray
`Attorney, Agent, or Firm-Baker & Botts, L.L.P.
`57
`ABSTRACT
`A method of producing a semiconductor device wherein a
`metal preform layer is applied to an expand tape followed by
`a step of adhering a wafer to the metal preform layer using
`an adhesive layer of a thin adhesive sheet on the preform
`layer. The metal preform layer and the wafer are cut into
`chips wherein each chip has adhered to the bottom a cut
`piece of the metal preform layer. The expand tape is then
`expanded to separate adjacent chips from each other, and
`each chip is then removed from the expanded expand tape
`and then die-bonded to a lead frame.
`
`1 Claim, 2 Drawing Sheets
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`MICRON 1032
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`U.S. Patent
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`Jun. 9, 1998
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`Sheet 1 of 2
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`5,762,744
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`F/G 1
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`MICRON 1032
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`U.S. Patent
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`Jun. 9, 1998
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`Sheet 2 of 2
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`5,762,744
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`FIG 3(3) PRIOR ART
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`11
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`FIG 3(C) PARIOR ART
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`MICRON 1032
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`BACKGROUND OF THE INVENTION
`The present invention relates to expand tapes for use at
`dicing of semiconductor wafers.
`A semiconductor device is generally manufactured
`through a cutting process of cutting a semiconductor crystal
`into semiconductor wafers, a dicing process of dicing the
`semiconductor wafer into semiconductor chips, a die
`bonding process of die-bonding the semiconductor chip to a
`package and so on.
`When the semiconductor wafer is diced, an expand tape
`has conventionally been used. The expand tape is made of a
`synthetic resin film which is expandable. At the dicing
`process, a wafer 14 is stuck onto a surface 11a of the expand
`tape as shown in FIG.3(a). Under this state, the wafer 14 is
`diced (see FIG.3(b)). When the expand tape 1 is expanded,
`the wafer 14 is separated into chips 15, 15.... , 15 (see FIG.
`3(c)). These chips 15 are then die-bonded onto lead frames,
`etc., using a preform material (e.g., a silver or solder paste)
`in the subsequent die-bonding process.
`Adicing process using the aforesaid conventional expand
`tape is separated from a die-bonding process. Thus, semi
`conductor device manufacturing processes involve a greater
`number of steps and require more hands. Further, there is
`another problem that the handling of the preform material in
`addition to the expand tape is required.
`SUMMARY OF THE INVENTION
`The invention has been made in view of the above
`circumstances. Accordingly, an object of the present inven
`tion is to provide an expand tape with which the number of
`semiconductor manufacturing steps as well as burden on
`material handling can be reduced.
`To achieve the above object, the expand tape of the
`present invention comprises a preform layer on an expand
`45
`able film.
`A wafer is diced into chips after being stuck onto the
`expand tape. Thereafter, when the chips are picked up from
`the expand tape, the preform material remains adhered onto
`the bottom of each chip. Therefore, the chip is ready to be
`die-bonded onto a lead frame, etc., immediately, thereby
`contributing to simplifying the steps and to decreasing
`hands. Further, the integration of the preform material with
`the expand tape allows material handling problem to be
`reduced.
`55
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`2
`DETALED DESCRIPTION OF THE
`INVENTION
`An embodiment of the invention will hereunder be
`described with reference to FIGS. 1 and 2.
`FIG. 1 shows a section of an expand tape 1, which is the
`embodiment of the invention. This expand tape 1 is formed
`of an expandable synthetic resin film 2, and a preform layer
`3 provided thereon. The shape of the expand tape may be
`circular. The preform layer 3 is formed by applying a
`conductive paste made of epoxy containing Agor polyimide
`containing Ag, a solder paste made of Sn-Pb, or a tape
`material made of Au-Si or Au-Ge to the synthetic resin
`film 2.
`FIGS. 2(a) to 20d) are diagrams sequentially showing a
`dicing process using the expand tape 1. First, a wafer 4 is
`adhered to the preform layer 3 of the expand tape 1 (see FIG.
`2(a)). The adhesion is carried out using thermal effects or an
`adhesive layer of a thin adhesive sheet 8 fixed to layer 3 by
`a roller or coating. Then, the wafer 4 is cut into chips 5,...,
`5 using a dicing saw such as a thin circular diamond blade
`(not shown). The cutting is carried out by, for example,
`moving the dicing saw along the surface of the expand tape
`1 from a portion on which the wafer is not adhered, through
`the wafer, to the other portion on which the wafer is not
`adhered. The depth of dicing grooves 6,..., 6 reaches the
`film 2 so that the preform layer 3 can also be cut (see FIG.
`2(b)).
`When tensile force is applied, for example, concentrically
`to the expand tape 1 to expand it under this state, the chips
`5.... , 5 are separated (see FIG. 2(c)). At the same time, the
`preform layer 3 are also separated into pieces 3a, . . . , 3a
`together with the chips 5, . . . , 5.
`Each diced chip 5 is picked up by being adsorbed by a
`collet 7 as shown in FIG. 2(d). Since the piece 3a of the
`preform layer is adhered on the bottom of the chip5, the chip
`5 is ready to be die-bonded onto a lead frame, etc.
`immediately, thereby allowing the semiconductor manufac
`turing processes to be simplified.
`As described in the foregoing, the expand tape of the
`present invention is formed of an expandable film and a
`preform layer provided thereon. As a result, not only the
`processes can be simplified and the hands involved in the
`processes can be decreased, but the burden on material
`handling can be reduced as well.
`What is claimed is:
`1. A method of producing a semiconductor device com
`prising the steps of:
`applying a metal paste preform layer to an expand tape;
`adhering a wafer to the preform layer on the expand tape;
`cutting said wafer and said preform layer into chips, each
`chip having adhered to one surface a cut piece of said
`preform layer;
`expanding said expand tape to separate said chips and said
`adhered cut pieces of said preform layer from adjacent
`chips and cut pieces;
`picking up each of said chips together with the corre
`sponding adhered cut piece of said preform layer; and
`die-bonding said each chip with said adhered cut piece of
`preform layer to a lead frame after said picking up step,
`wherein said adhering step is carried out through an
`adhesive layer of a thin adhesive sheet fixed to said
`preform layer.
`
`5,762,744
`
`1
`METHOD OF PRODUCING A
`SEMCONDUCTOR DEVICE USING AN
`EXPAND TAPE
`
`This application is a continuation of application Ser. No.
`08/200,290, filed on Feb. 22, 1994, now abandoned, which
`is a division of application Ser. No. 07/816398, filed Dec.
`27, 1991 now U.S. Pat. No. 5.316,853.
`
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`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a sectional view showing the main portion of an
`expand tape, which is an embodiment of the invention;
`FIGS. 2(a) to 2(d) are diagrams illustrative of a dicing
`process using the expand tape of the invention in sequence;
`and
`FIGS. 3(a) to 3(c) are diagrams illustrative of a dicing
`process using a conventional expand tape.
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`MICRON 1032
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