JP3634508B2 - Tape carrier for semiconductor device, method for manufacturing the same, and tape carrier type semiconductor device using the tape carrier - Google Patents

Description

【００２５】
次に最適条件についてリードパターンの硬さとボンディング性とを評価した。ボンディング性の評価には、Ａｌからなるボンディング用電極パッドのみ形成したワイヤボンディング用の半導体素子を使用し、超音波併用熱圧着方式のシングルポイントボンダーにより、２３０℃、ツール荷重２０〜５０ｇの条件でボンディングを行った。評価はリード引張試験による接合部剥がれ率及びリードを除去した後のボンディング用電極パッドの観察によるクラック発生率で比較した。
【００２６】
表１から明らかなように、硬質の電解銅箔を用いた比較例では、熱処理後においてもビッカース硬さが１６０までしか軟化していないことから、Ａｕめっき膜の厚さが１μｍと薄い場合、接合強度とチップダメージの抑制とを両立させることが困難であった。よって、接合強度とチップダメージの抑制とを両立させるには、Ａｕめっき膜の厚さを３μｍと厚くする必要があった。これに対して、ＯＦＣ（無酸素銅）圧延箔を用いた実施例では、熱処理後、ビッカース硬さがそれぞれ１３０，１１０まで軟化していることから、Ａｕめっき膜の厚さが１μｍと薄い場合においても、良好なボンディング性が得られることが分かる。
【００２７】
以上において、本実施の形態によればリードパターン１３が軟質の銅箔からなるので、ボンディング時の応力がインナーリード１３ａ自体で緩和されるため、チップダメージが効果的に防止される。また、バンプレスボンディングにおいても、テープキャリア１０のＡｕめっき膜１５の厚さを厚くする必要がないので、チップ（半導体素子）コスト、テープキャリアコストを大幅に削減できる。さらに、バンプ付チップ、バンプレスチップのいずれを用いる場合においても、ボンディングの適性条件の範囲が拡がるので接続信頼性や歩留まりが向上する。
【００２８】
尚、本実施の形態ではＡｕバンプを用いない通常の半導体素子の場合で説明したが、これに限定されるものではなく、半導体素子としてＴＡＢ用のバンプ付き半導体素子を用いてもよく、例えばギャングボンディングにおけるバンプ高さのばらつきや、ツールボンディング面の平衡度不良に起因するチップダメージの抑制に効果がある。また、ＴＡＢテープキャリアを用いて半導体素子を搭載するＴＣＰ、テープＢＧＡ等の半導体パッケージに応用してもよい。
【発明の効果】
【００２９】
以上要するに本発明によれば、次のような優れた効果を発揮する。
【００３０】
半導体装置用テープキャリアにおいて、熱処理前のビッカース硬さが１３０よりも大きく、熱処理によりそのビッカース硬さを１３０以下に軟化形成させた軟質銅で構成された上記リードパターンを作製した後、そのリードパターンの少なくともインナーリードの表面に、直接、上記Ａｕめっき膜をめっき形成することにより、テープキャリアを半導体素子表面のボンディング用電極パッドにボンディングする際の応力をリードパターンのインナーリード自体で緩和することができ、インナーリードのＡｕめっき膜の厚さを厚くすることなくチップダメージを防止することができる。
【図面の簡単な説明】
【００３１】
【図１】本発明の半導体装置用テープキャリアの一部断面図である。
【図２】図１に示した半導体装置用テープキャリアを用いたテープキャリア型半導体装置の断面図である。
【図３】従来のテープキャリア型半導体装置の断面模式図である。
【符号の説明】
【００３２】
１０ 半導体装置用テープキャリア（テープキャリア）
１２ 絶縁性フィルム（ポリイミドフィルム）
１３ リードパターン
１３ａ インナーリード
１５ Ａｕめっき膜 BACKGROUND OF THE INVENTION
[0001]
The present invention relates to a tape carrier for a semiconductor device, a manufacturing method thereof, and a tape carrier type semiconductor device using the tape carrier.
[Prior art]
[0002]
One type of IC packaging technology is the TAB (Tape Automated Bonding) method. This, for example, a lead pattern pasted copper foil on the film tape 35mm width is formed by photoetching, a method of thermocompression bonding an electrode pad for bonding the semiconductor element surface.
[0003]
The TAB method for directly connecting the inner lead of the tape carrier and the semiconductor element has features such as narrow pitch connection, thinner package, and smaller size as compared with the wire bonding method. Widely used for TCP (Tape Carrier Package), mainly LSI. Recently, it is also applied to a BGA (Ball Grid Array) type package in which external terminals are formed of solder balls.
[0004]
FIG. 3 is a schematic cross-sectional view of a TCP type package as a conventional tape carrier type semiconductor device.
[0005]
A tape carrier (hereinafter referred to as “tape carrier”) 1 for a semiconductor device includes a base film 2 and a lead pattern 3 formed on the surface thereof, and a device hole in which an inner lead 3 a of the lead pattern 3 is opened in the base film 2. 4 is formed so as to protrude toward the inside. Inner leads 3a, the plating has been applied to the surface, heat by gang bonding (collectively bonding) method or a single point bonding method Au bumps 7 protruding provided on the bonding electrode pads 6 of the semiconductor element 5 Crimp connected. After the thermocompression bonding, the TCP package is formed by sealing the semiconductor element 5 together with the connecting portion of the inner lead 3a in the device hole 4 with the resin 8.
[Problems to be solved by the invention]
[0006]
By the way, according to the conventional example shown in FIG. 3, the stress applied to the semiconductor element 5 from the bonding tool through the inner lead 3a during the pressure bonding is relaxed by the soft Au bump 7 to damage the semiconductor element 5 ( The effect of suppressing chip damage) can be obtained, but the semiconductor element 5 with the Au bumps 7 has more manufacturing processes and is more expensive than a normal semiconductor element, and the acquisition itself may be difficult.
[0007]
For this reason, recently, a bumpless bonding method has been proposed in which an Au-plated inner lead is directly bonded to an Al bonding electrode pad without providing an Au bump on a semiconductor element, but chip damage due to stress during bonding is proposed. to prevent, it is necessary to considerably thicker than the thickness of the Au plating film bonding to the bumped chip in the inner lead of the tape carrier is not necessarily cost effective.
[0008]
An object of the present invention is to solve the above problems, without increasing the thickness of the Au plating film of the inner lead, the tape carrier and a manufacturing method thereof for a semiconductor device can be prevented chip damage as well as the tape carrier To provide a tape carrier type semiconductor device using
[Means for Solving the Problems]
[0009]
In order to achieve the above object, a tape carrier for a semiconductor device of the present invention has a lead pattern made of a conductor on one surface of an insulating film, and a semiconductor having an Au plating film on at least the inner lead surface of the lead pattern. In the tape carrier for equipment,
Vickers hardness before the heat treatment is much larger than the 130, after the Vickers hardness was prepared the lead pattern made of a soft copper softened form to 130 or less by heat treatment, the surface of at least the inner leads of the lead pattern Further, the above Au plating film is directly provided.
[0010]
Tape carrier for semiconductor device of the present invention in addition to the above configuration, the lead pattern, also is preferable constructed using the rolled copper foil having a softening temperature of 200 ° C. or less (200 ° C. is excluded).
[0011]
The method for manufacturing a tape carrier for a semiconductor device according to the present invention is for a semiconductor device having a lead pattern made of a conductor on one surface of an insulating film and an Au plating film on at least the surface of the inner lead of the lead pattern. In the tape carrier manufacturing method,
Vickers hardness before the heat treatment is much larger than the 130, after the Vickers hardness was prepared the lead pattern made of a soft copper softened form to 130 or less by heat treatment, the surface of at least the inner leads of the lead pattern In addition, the Au plating film is directly formed by plating.
[0012]
Furthermore, the tape carrier type semiconductor device of the present invention is obtained by connecting the inner lead of the above-described tape carrier for a semiconductor device and the bonding electrode pad on the surface of the semiconductor element by ultrasonic thermocompression bonding.
[0013]
In the tape carrier type semiconductor device of the present invention in addition to the above configuration, the bonding electrode pad of the semiconductor element is preferably an Au film-pressed Al film electrode pad .
[0014]
By the above-described configuration lever, and the inner lead of the tape carrier, when connecting by ultrasonic thermocompression bonding a bonding electrode pads of the semiconductor device surface (bonding) is possible to relieve the stress at the time of bonding an inner lead itself And chip damage is prevented. Moreover, since the thickness of the Au plating film of the inner lead is not increased more than necessary, the cost can be reduced.
DETAILED DESCRIPTION OF THE INVENTION
[0015]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0016]
FIG. 1 is a partial sectional view of a tape carrier for a semiconductor device according to the present invention, and FIG. 2 is a sectional view of a tape carrier type semiconductor device using the tape carrier for a semiconductor device shown in FIG.
[0017]
1 has a lead pattern 13 made of soft copper bonded to one surface (upper surface in the figure) of a polyimide film 12 as an insulating film having a device hole 11 formed in the center. Bonded with the agent 14. An Au plating film 15 is directly provided on the surface of the lead pattern 13. The alternate long and short dash line L16 indicates the position where the semiconductor element 16 is disposed, and the alternate long and short dash line L17 indicates the position of the bonding electrode pad 17 of the semiconductor element 16.
[0018]
2, is connected bonding electrode pads 17 of the semiconductor device 16 disposed in the device hole 11 of the semiconductor device tape carrier 10 and the inner lead 13a is a single point bonder ultrasonic thermocompression bonding method (bonding) ing. The bonding electrode pad 17 of the semiconductor element 16 is an electrode pad (Au bumpless electrode pad) having no Au bump on its surface. Therefore, on the bonding electrode pad 17 since Au bump 7 is not shown in FIG. 3, the connecting portion of the inner leads 13a are bent into a substantially crank shape when bonding by that the thickness of. This is because the inner lead 13a bends due to the stress at the time of bonding, and this reduces the impact on the semiconductor element 16. The tape carrier type semiconductor device 19 is formed by sealing the semiconductor element 16 together with the connecting portion of the inner lead 13a with the resin 18.
[0019]
Here, the hardness of the lead pattern 13 made of copper foil is 130 or less in Vickers hardness during bonding. The electrolytic copper foil normally used for TAB tape carriers is not suitable because it has a high hardness and is not easily softened by heat treatment. Therefore, a copper foil manufacturing stage or a tape carrier manufacturing stage using a rolled copper foil made of soft copper having a Vickers hardness of greater than 130 before heat treatment and softening at a low temperature of 200 ° C. or less (excluding 200 ° C.). in by heat treatment before the formation of the Au-plated film 15, it is tempered to 130 following Vickers hardness. Further, it is desirable that the semiconductor device is configured by using a normal semiconductor element having no Au bump as the semiconductor element 16. Furthermore, the Au plating film 15 may have a minimum thickness.
[0020]
Next, a manufacturing method of the semiconductor device tape carrier shown in FIG. 1 will be described in comparison with an example.
[0021]
A polyimide film 12 having an epoxy adhesive 14 on one surface and having a thickness of about 75 μm was pressed to form openings such as device holes 11 and sprocket holes (not shown) . As after, its polyimide film 12, a thickness of about 35 [mu] m, the initial Vickers hardness is laminated with a heat roll OFC (oxygen-free copper) rolled foil is 150. Thereafter, in order to cure the epoxy adhesive 14, heating was performed for 4 hours under two conditions of about 150 ° C. and 170 ° C. to prepare two types of laminated tapes. Next, after a lead pattern 13 including an inner lead 13a having a width of 40 μm is formed by a photo-etching method, an Au plating film 15 having a thickness of about 1 μm is directly formed on the surface of the lead pattern 13, whereby FIG. (Example) A tape carrier 10 for a semiconductor device as shown in FIG.
[0022]
As a comparative example , an electrolytic copper foil (electrolytic VLP foil) having an initial Vickers hardness of 170 was used as a conductor, and a tape carrier for a semiconductor device was produced by the method described above. The heat treatment conditions for curing the adhesive were 170 ° C. × 4 hours, and the two conditions of about 1 μm and 3 μm were compared for the thickness of the Au plating film.
[0023]
The comparison results are shown in Table 1.
[0024]
[Table 1]

[0025]
Next, the lead pattern hardness and bondability were evaluated under optimum conditions. The evaluation of the bonding properties, using the semiconductor device for wire bonding was formed only bonding electrode pad made of Al, the single-point bonder ultrasonic thermocompression bonding method, 230 ° C., a tool load 2 0～50G conditions Bonding was performed. The evaluation was compared with the crack occurrence rate due to bonding of the electrode pads observation after removal of the junction peeling rate and read by the read tensile test.
[0026]
As is clear from Table 1, in the comparative example using the hard electrolytic copper foil, the Vickers hardness is only softened up to 160 even after the heat treatment, so when the thickness of the Au plating film is as thin as 1 μm , it was Tsu difficult der to achieve both suppression of joint strength and chip damage. Therefore, in order to achieve both the suppression of the bonding strength and chip damage was Tsu need to as thick as 3μm thickness of the Au plating film. On the other hand, in the example using OFC (oxygen-free copper) rolled foil , the Vickers hardness is softened to 130 and 110, respectively, after the heat treatment, so the thickness of the Au plating film is as thin as 1 μm. in also seen that good bonding can be obtained.
[0027]
In the above, the lead pattern 13 according to this embodiment is so made of a copper foil of soft, stress at bonding because is relaxed by the inner lead 13a itself, chip damage is effectively prevented. Also in bumpless bonding, there is no need to increase the thickness of the Au plating layer 15 of the tape carrier 10, the chip (semiconductor element) cost, the tape carrier cost can be greatly reduced. Furthermore, in the case of using either a bumped chip or a bumpless chip, the range of suitable bonding conditions is expanded, so that connection reliability and yield are improved.
[0028]
In the present embodiment, the case of a normal semiconductor element that does not use Au bumps has been described. However, the present invention is not limited to this, and a semiconductor element with bumps for TAB may be used as the semiconductor element. It is effective in suppressing chip damage caused by variations in bump height during bonding and poor balance of the tool bonding surface. Moreover, you may apply to semiconductor packages, such as TCP and tape BGA which mount a semiconductor element using a TAB tape carrier.
【The invention's effect】
[0029]
In short, according to the present invention, the following excellent effects are exhibited.
[0030]
In the tape carrier semiconductor device, Vickers hardness before the heat treatment is much larger than the 130, after the Vickers hardness was prepared the lead pattern made of a soft copper softened form to 130 or less by the heat treatment, the read By plating the Au plating film directly on at least the inner lead surface of the pattern, the stress when the tape carrier is bonded to the bonding electrode pad on the surface of the semiconductor element is relieved by the inner lead of the lead pattern itself. Thus, chip damage can be prevented without increasing the thickness of the Au plating film of the inner lead.
[Brief description of the drawings]
[0031]
FIG. 1 is a partial cross-sectional view of a tape carrier for a semiconductor device of the present invention.
2 is a cross-sectional view of a tape carrier type semiconductor device using the semiconductor device tape carrier shown in FIG. 1. FIG.
FIG. 3 is a schematic cross-sectional view of a conventional tape carrier type semiconductor device.
[Explanation of symbols]
[0032]
10 Tape carrier for semiconductor devices (tape carrier)
12 Insulating film (polyimide film)
13 Lead pattern 13a Inner lead 15 Au plating film

Claims (5)

In a tape carrier for a semiconductor device having a lead pattern made of a conductor on one surface of an insulating film, and having an Au plating film on at least the surface of the inner lead of the lead pattern,
Vickers hardness before the heat treatment is much larger than the 130, after the Vickers hardness was prepared the lead pattern made of a soft copper softened form to 130 or less by heat treatment, the surface of at least the inner leads of the lead pattern A tape carrier for a semiconductor device, wherein the Au plating film is directly provided on the tape carrier. The tape carrier for a semiconductor device according to claim 1, wherein the lead pattern is configured using a rolled copper foil having a softening temperature of 200 ° C. or less (excluding 200 ° C.). In the manufacturing method of a tape carrier for a semiconductor device having a lead pattern made of a conductor on one surface of the insulating film and having an Au plating film on the surface of at least the inner lead of the lead pattern,
Vickers hardness before the heat treatment is much larger than the 130, after the Vickers hardness was prepared the lead pattern made of a soft copper softened form to 130 or less by heat treatment, the surface of at least the inner leads of the lead pattern A method of manufacturing a tape carrier for a semiconductor device, wherein the Au plating film is directly formed by plating. 3. A tape carrier type semiconductor device comprising an inner lead of a tape carrier for a semiconductor device according to claim 1 and a bonding electrode pad on the surface of the semiconductor element connected by ultrasonic thermocompression bonding. 5. The tape carrier type semiconductor device according to claim 4, wherein the bonding electrode pad of the semiconductor element is an Al film electrode pad of Au bump press.

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