JP3695303B2 - TAB tape and semiconductor device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a TAB tape and a semiconductor device using the TAB tape, and in particular, a TAB tape that is excellent in dimensional stability and heat resistance when forming fine wiring and can be manufactured using existing equipment, and the same. The present invention relates to a semiconductor device.
[0002]
[Prior art]
In a conventional semiconductor device, a wireless bonding method is known in which a semiconductor chip and a lead electrode are electrically connected without using a gold wire. In this wireless bonding method, TAB connection based on a TAB (Tape Automated Bonding) tape using an insulating film is known. In recent years, semiconductor devices have been miniaturized and highly integrated, and also have heat dissipation and heat resistance. It is known that even if it has sex, it has excellent characteristics.
[0003]
FIG. 8 shows a semiconductor device using a conventional TAB tape, which is formed on a TAB tape 30 having a copper wiring pattern 33 affixed to an insulating film 31 via an adhesive 32, and an inner lead 34 of the TAB tape 30. The bump 35, the solder resist 37 that protects the outer lead 36, the semiconductor chip 38 that is bump-bonded to the inner lead 34, and the potting resin 39 that seals the inner lead and the semiconductor chip 38 are formed.
[0004]
The insulating film 31 is formed of an organic polyimide tape, glass epoxy tape, etc. (water absorption 1.4% or less) having a thickness of 50 μm to 125 μm, a width of 35 mm, 48 mm, or 70 mm, and a thickness of 8 μm. A copper wiring pattern 33 having a thickness of 18 μm to 35 μm made of a copper foil such as a rolled copper foil or an electrolytic copper foil is bonded through an adhesive 32 of 24 μm to 24 μm. Further, Sn electroless plating 40 is applied to the surface of the copper wiring pattern 33.
[0005]
FIG. 9 shows a bonder for TAB-bonding the TAB tape 30 and the semiconductor chip 38. The stage 13 on which the semiconductor chip 38 is mounted, the bonding tool 14 disposed above the stage 13, and the bonding tool 14 are provided. CCD camera 15 is provided.
[0006]
The bonding of the TAB tape 30 and the semiconductor chip 38 by the bonder is recognized by mounting the semiconductor chip 38 on the stage 13, placing the TAB tape 30 on the stage 13, and transmitting the TAB tape 30 through the CCD camera 15. After confirming that the semiconductor chip 38 is in a predetermined position, the TAB tape 30 is heated and pressed to the semiconductor chip 38 with the bonding tool 14 to perform bump bonding. After bump bonding, the periphery of the semiconductor chip 38 is sealed with potting resin (not shown).
[0007]
[Problems to be solved by the invention]
However, according to the conventional semiconductor device, if the transparency of the insulating film is low, it becomes difficult to align the TAB tape and the semiconductor chip at the time of bonding, so it is necessary to modify or change the bonder for the alignment. This increases the manufacturing cost. Further, if the insulating film is made thin in order to obtain transparency, there is a problem that warpage or plating peeling is likely to occur due to a decrease in heat resistance, resulting in a decrease in yield and productivity.
[0008]
Accordingly, an object of the present invention is to provide a TAB tape that can be used without modifying or changing existing equipment, and has excellent dimensional stability during production without reducing yield and productivity, and a semiconductor device using the TAB tape. It is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a first insulating film having an L value indicating transparency of greater than 35,
Adhering a copper foil layer forming a copper wiring pattern to the first insulating film, an adhesive having a glass transition temperature greater than 180 ° C. in a range of water absorption of 0.2% to 2.7%;
A second insulating film made of an aramid tape , which is adhered to the first insulating film with the adhesive and has an L value of 35 greater than 35 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. Provide TAB tape.
[0011]
Moreover, in order to achieve the above object, the present invention provides a first insulating film having an L value indicating transparency greater than 35, and
Adhering a copper foil layer forming a copper wiring pattern to the first insulating film, an adhesive having a glass transition temperature greater than 180 ° C. in a range of water absorption of 0.2% to 2.7%;
A second insulating film made of an aramid tape , which is adhered to the first insulating film with the adhesive and has an L value of 35 greater than 35 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. A semiconductor device bonded to a semiconductor chip using a TAB tape is provided.
[0012]
According to the present invention, by using an insulating film whose transparency does not easily change due to a change in thickness, it is possible to accurately align the two regardless of the arrangement of the insulating film and the semiconductor chip during bonding.
[0013]
The water absorption rate of the adhesive is preferably in the range of 0.8% (when immersed in water at 23 ° C. for 24 hours) to 2.7%. If it is less than 0.2%, there is a problem that it becomes difficult for the adhesive layer to absorb moisture of the die bonding agent and the transfer mold resin. On the other hand, if the adhesive is 2.7% or more, during reflow heating (temperature of about 240 ° C.), moisture may not be released from the adhesive layer only by the adhesive layer and cracks (delamination) may occur. There is.
[0014]
The glass transition temperature Tg of the adhesive is preferably 180 ° C. or higher in order to have characteristics that can withstand heating at about 200 ° C. for about 4 seconds in flip chip bonding.
[0015]
The insulating film with adhesive preferably has an L value of 35 or more, which is an index of light transmission. This is based on the fact that the ILB bonder for the TAB tape requires the light transmittance of the insulating film when aligning the semiconductor chip, and the L value = 35 or more is necessary as an index thereof.
[0016]
This is because the copper foil layer has a thickness in the range of 3 μm to 25 μm to improve etching accuracy. The reason why the thickness is 3 μm or more is to ensure good adhesion strength with the adhesive even at the roughened surface maximum roughness Rz = 2.5 μm of the copper foil layer.
[0017]
The first and second insulating films are laminated with an insulating film having a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. as a warp prevention. Thereby, the deformation | transformation of the insulating film with an adhesive agent is prevented by canceling using the curvature characteristic of the insulating film from which an expansion coefficient differs.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a TAB tape of the present invention and a semiconductor device using the TAB tape will be described in detail with reference to the drawings.
[0019]
FIG. 1 shows a cross section of a TAB tape 11 as an example according to the first embodiment of the present invention. As shown in FIG. 1A, an insulating film (Kapton EN: 38 μm thick and 35 μm wide) is used. Manufactured by Toyo Metallizing Co., Ltd. 1, an adhesive 2 having a water absorption of 1.2% and a thickness of 8 μm, an aramid tape 3 having a thickness of 9 μm and a width of 35 mm, and an adhesive 4 having a water absorption of 1.2% and a thickness of 8 μm The electrolytic copper foil 5 having a thickness of 9 μm and a roughened surface maximum roughness of 1.5 μm is laminated. FIG. 1B shows a state in which a copper wiring pattern 5A having a lead pitch of 34 μm or 50 μm based on a photoresist and an etching process is formed on the TAB tape 11 and Sn plating 6 is applied to the surface by electroless plating or electroplating. Is shown. The insulating film 1 has a water absorption rate of 1.7% and an L value showing transparency of 54, and the aramid tape 3 has an L value of 50 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. .
[0020]
FIG. 2 shows a cross section of a TAB tape 21 formed as a comparative example. As shown in FIG. 2A, an insulating film (Kapton EN: manufactured by Toyo Metallizing) 6 having a thickness of 38 μm and a width of 35 μm, Constructed by laminating an aramid tape 7 having a width of 9 μm and a width of 35 mm, an adhesive 8 having a water absorption rate of 1.2% and a thickness of 8 μm, and a Cu plating layer having a thickness of 8 μm formed on the insulating film 6 by Cu plating after sputtering. Has been. FIG. 2B shows a state in which a copper wiring pattern 9A having a lead pitch of 34 μm or 50 μm based on a photoresist and an etching process is formed on the TAB tape 21 and Sn plating 10 is applied to the surface by electroless plating or electroplating. Is shown. The insulating film 6 has a water absorption rate of 1.7% and an L value of 54, and the aramid tape 3 has an L value of 50 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C.
[0021]
FIG. 3 shows a schematic configuration of a color meter for measuring the L value, and the transparency of the TAB tapes 11 and 21 is measured based on the principle of color measurement using the color meter. The color meter comprises a light source 16 such as a tungsten lamp for irradiating the measurement light L, and the half mirror 17A and 17B for splitting reflected light L _R reflected by the TAB tape 11 and 21, the color temperature conversion of the dispersed light Color temperature conversion filters 18A, 18D, and 18G for performing tristimulus values, tristimulus value filters 18B, 18E, and 18H for extracting tristimulus values, and sensitivity correction filters 18C, 18F, and 18 for performing spectral sensitivity correction before receiving the light receiver. 18I and light receivers 19R, 19G, and 19B that receive light that has passed through the filters. In the figure, the dispersed light passes through a color temperature conversion filter, a tristimulus filter, and a sensitivity correction filter (hereinafter, this combination is referred to as a light receiver filter) and enters a light receiver corresponding to the three primary colors of RGB. To do.
[0022]
FIG. 4 shows a method for calculating the L value in the color meter, FIG. 4 (a) shows the composite spectral sensitivity of the receiver filter provided in the optical path of the receiver 19R, and FIG. 4 (b) shows the received light value. (Tristimulus value) X is shown. The light receiver outputs a current value corresponding to the area indicated by oblique lines with respect to the tristimulus value X to a measuring device (not shown). FIG. 4C shows the composite spectral sensitivity of the light receiver filter provided in the optical path of the light receiver 19G, and FIG. 4D shows the light reception value (tristimulus value) Y. FIG. 4E shows the composite spectral sensitivity of the light receiver filter provided in the optical path of the light receiver 19B, and FIG. 4F shows the received light value (tristimulus value) Z.
[0023]
The tristimulus values XYZ for RGB are obtained by equations (1) to (3) based on the energy distribution Pλ of the light source, the reflectance ρλ of the object, and the spectral tristimulus values xλ, yλ, zλ, Based on the calculated Y, the L value is calculated from Equation (4).
[0024]
FIG. 5 shows a bonding process (TAB method) between the TAB tape and the semiconductor chip. As shown in FIG. 5A, the TAB tapes 11 and 21 are supplied to the bonder with the copper wiring patterns 5A and 9A facing downward. Further, as shown in (b) and (c), bumps 12A are formed on the electrode portions of the semiconductor chip 12 with solder, gold, etc., and after heating to about 500 ° C., the bump forming surface is shown as shown in (d). Fix it to the bonder stage 13 with the top facing up. After fixing, the CCD camera 15 confirms that the joining position of the semiconductor chip 12 is at a predetermined position through the TAB tapes 11 and 21, and lowers the bonding tool 14 heated to 100 ° C. to lower the TAB tapes 11 and 21. The semiconductor chip 12 was pressed and bonded for about 3 seconds.
[0025]
According to the TAB tape 11 of this example, excellent transparency was obtained, and excellent bonding properties were obtained without causing warping of the tape at any lead pitch of 34 μm and 50 μm. Moreover, it is excellent in insulation resistance and migration resistance, and can be applied to fine wiring having a lead pitch of 50 μm or less. On the other hand, in the TAB tape 21 of the comparative example, when Sn plating was performed after the formation of the copper wiring pattern 9A, the penetration of the wiring pattern occurred due to the penetration of Sn. In particular, it was confirmed that when the lead pitch was 34 μm, the entire surface was peeled and the quality of the TAB tape could not be obtained.
[0026]
FIG. 6 shows a bonding process (flip chip method) using a Flip Chip-ILB bonder. As shown in FIG. 6A, the TAB tape 11 is fixed to the bonder stage 13 with the copper wiring pattern 5A facing up. Further, as shown in (b) and (c), bumps 12A are formed on the electrode portions of the semiconductor chip 12 with solder, gold, etc., and as shown in FIG. 14 is fixed. After fixing, the semiconductor chip 12 and the TAB tape 11 were aligned by the CCD cameras 15A and 15B, and then the bonding tool 14 was lowered to press the TAB tape 11 and the semiconductor chip 12 and joined by solder reflow.
[0027]
As described above, according to the TAB tape 11 of this embodiment, excellent bonding properties can be obtained without causing warping of the tape even with a Flip Chip-ILB bonder that does not require transparency of the TAB tape.
[0028]
FIG. 7 shows a cross section of a TAB tape according to the second embodiment of the present invention, in which a solder resist 20 is applied to the copper wiring pattern 5A. Other configurations are the same as those of the TAB tape described in the first embodiment. In addition to the solder resist, a photoresist can be applied.
[0029]
The above-mentioned TAB tape is a COF (Chip On Film) TAB tape, which is a single-side potting or transfer mold type, and has excellent insulation resistance and migration resistance characteristics. It can be applied to Tape BGA (Ball Grid Array) flip chip type and wire bonding type CSPs.
[0030]
【The invention's effect】
As described above, according to the TAB tape of the present invention and the semiconductor device using the TAB tape, the insulating film having a predetermined mechanical strength and flatness and having a predetermined transparency that can be seen through from one surface to the other surface. Since the lead pattern is formed on one surface, the existing equipment can be used without modification, change, etc., and the dimensional stability during production can be improved without reducing the yield and productivity.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a TAB tape according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a TAB tape formed as a comparative example of the present invention. [FIG. 4] (a) to (f) are explanatory views showing a method of calculating an L value in a color meter. [FIG. 5] A bonding process of a TAB tape and a semiconductor chip according to the first embodiment of the present invention. FIG. 6 is an operation diagram showing a bonding process of a TAB tape and a semiconductor chip by a Flip Chip-ILB bonder according to the first embodiment of the present invention. FIG. 7 is a second embodiment of the present invention. FIG. 8 is a cross-sectional view of a conventional semiconductor device using a TAB tape. FIG. 9 is a side view of a bonder that joins the TAB tape and a semiconductor chip.
1, insulating film 2, adhesive 3, aramid tape 4, adhesive 5, electrolytic copper foil 5A, copper wiring pattern 6, insulating film 7, aramid tape 8, adhesive 9A, copper wiring pattern 11, tape 12A, Bump 12, semiconductor chip 13, stage 14, bonding tools 5A, 9A, wiring pattern 15, CCD camera 15A, 15B, CCD camera 16, light source 17A, half mirror 18A, color temperature conversion filter 18B, tristimulus value filter 18C, sensitivity Correction filter 19R, light receiver 19G, light receiver 19B, light receiver 20 solder resist 21, tape 30, tape 31, insulating films 11, 21, tape 32, adhesive 33, wiring pattern 34, inner lead 35, bump 36, Outer lead 37, solder resist 38, semiconductor chip 39, potting Resin

Claims (2)

A first insulating film having an L value indicating transparency greater than 35;
Adhering a copper foil layer forming a copper wiring pattern to the first insulating film, an adhesive having a glass transition temperature greater than 180 ° C. in a range of water absorption of 0.2% to 2.7%;
A second insulating film made of an aramid tape , which is adhered to the first insulating film with the adhesive and has an L value of 35 greater than 35 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. TAB tape characterized by this. A first insulating film having an L value indicating transparency greater than 35;
Adhering a copper foil layer forming a copper wiring pattern to the first insulating film, an adhesive having a glass transition temperature greater than 180 ° C. in a range of water absorption of 0.2% to 2.7%;
A second insulating film made of an aramid tape , which is adhered to the first insulating film with the adhesive and has an L value of 35 greater than 35 and a thermal expansion coefficient of 4 × 10 ⁻⁶ / ° C. A semiconductor device which is bonded to a semiconductor chip using a TAB tape.

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