JP2002203877A - Tape carrier and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape carrier for BGAs and a semiconductor device using thereof having a high reliability of a bonding strength of solder balls and is superior in a bonding performance. SOLUTION: In the tape carrier wherein a wiring circuit is formed by a copper foil 6 on one side of a polyimide resin film being an insulation material, wire bonding pads 4 for a connection to a semiconductor are formed on one end of the wiring circuit and pads 3 for solder balls attachment on another end, Ni/Au platings 7, 8 are performed on the wire bonding pads and either of the Au plating 8, a Sn plating 9 or a solder plating 10 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape carrier as a precision electronic component and a semiconductor device using the same, and more particularly to a wiring tape carrier for mounting a semiconductor element having pads for mounting solder balls and a BGA type using the same. (Ball Grid Array).

[0002]

2. Description of the Related Art Generally, as shown in FIG. 5A, a wiring tape carrier for mounting a semiconductor element has a wiring circuit (copper foil pattern) with a copper foil 6 on one surface of a polyimide resin film 1 which is an insulating material. And a wire bonding pad 4 for semiconductor connection is formed at one end of the wiring circuit, and a solder ball mounting pad 3 is formed at the other end, and a wiring circuit in the area of the solder ball mounting pad 3 is formed. An insulating film 2 is formed on the surface except for an electrical connection portion. In the structure of the conventional wiring tape carrier for mounting a semiconductor element, as shown in FIGS. 5B and 5C, the wire bonding pads 4 and the solder ball mounting pads 3 are plated with Ni / Au. . That is,
An Ni plating layer 7 is formed as a base layer, and an Au plating layer 8 is formed thereon.

In a form in which this tape carrier is used as a wiring tape for mounting a semiconductor element, a gold wire is wire-bonded to a pad surface of a wire bonding pad 4 of the tape carrier, and a solder ball mounting pad 3 is provided.
Is mounted on the land surface of the semiconductor device and processed into a package of a BGA type semiconductor device.

[0004]

As described above, in the conventional wiring tape for mounting a semiconductor element, Ni / Au plating is applied to the wire bonding pad 4 and the Ni / Au plating is also applied to the solder ball mounting pad 3. Plating had been applied.

[0005] Generally, in gold wire bonding,
Ultrasonic heating bonding of a gold wire is performed on the gold plating on the pad surface. Therefore, this method is considered to be suitable for rigid frame materials, but since the tape carrier is a soft material compared to the lead frame material, the bonding load and ultrasonic output are absorbed by the polyimide resin, It does not transmit efficiently to the membrane itself. Therefore, when gold wire bonding is performed on the tape carrier, it is inferior to the wire peel strength when gold wire bonding is performed on the lead frame material.

Therefore, the tape carrier is not suitable as a material for performing gold wire bonding. Therefore,
To achieve good wire bonding properties, the Au plating thickness must be increased to a certain level or more.

On the other hand, in order to maintain the bonding reliability of the solder balls, the weight concentration of Au to the solder after mounting the solder balls must be kept at a certain level or less. Therefore, when the size of the solder ball used is small, the Au plating thickness must be reduced in order to keep the weight concentration of Au with respect to the solder at a certain level or less.

However, in the conventional tape carrier, since the wire bonding pad and the solder ball attaching pad are plated at the same time, Ni is applied to both the wire bonding pad and the solder ball attaching pad.
/ Au plating is applied, and it is difficult to improve both the wire bonding property and the solder ball bonding reliability.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a BGA tape carrier having high reliability of solder ball bonding strength and excellent wire bonding properties, and a semiconductor device using the same. is there.

[0010]

In order to achieve the above object, a tape carrier according to the present invention has a wiring circuit formed of copper foil on one side of an insulating film, and one end of the wiring circuit has a wire for connecting a semiconductor. In a wiring tape carrier for mounting a semiconductor element, wherein a bonding pad is formed and a solder ball mounting pad is formed at the other end, a Ni plating layer is formed as a base layer on the wire bonding pad, and an Au plating layer is formed thereon. To form
Further, an Au plating layer is formed on the solder ball mounting pad (claim 1).

According to the present invention, only the Au plating is applied to the solder ball mounting pad. As shown in FIG. 2, in the case of the conventional method in which Ni / Au plating is performed, the weight concentration of Au to the solder after the solder ball is mounted must be kept below a certain level in order to maintain the bonding reliability of the solder ball. Therefore, when the size of the solder ball used is small, the Au plating thickness must be reduced in order to keep the weight concentration of Au with respect to the solder at a certain level or less.
That is, the conventional Ni / Au-plated A
When the thickness of the u plating increases, the solder ball bonding strength after the reliability test decreases, but in the case of only the Au plating of the present invention,
Even if the Au plating thickness is increased, the solder ball bonding strength after the reliability test does not decrease. Therefore, the Au plating thickness can be increased, and good wire bonding properties can be obtained.

In addition, Ni / A is applied to the wire bonding pad.
u plating, and solder ball mounting pad is Au
Even if an Sn plating layer is formed instead of the plating layer (Claim 2), or a solder plating layer is formed instead of the Au plating layer (Claim 3), the reliability of the solder ball bonding strength is similarly high. In addition, a tape carrier having excellent wire bonding properties can be obtained.

Using these tape carriers, a semiconductor element is mounted on the tape carrier, an electrode of the semiconductor element and a wire bonding pad are wire-bonded with a gold wire, and a solder ball is melted on a solder ball mounting pad. By mounting, a BGA package having high reliability of solder ball bonding strength and excellent wire bonding properties is manufactured (claim 4).

<The gist of the invention> Since the copper foil of the TAB tape is made of a thin material, it is extremely soft, and it is difficult to wire-bond directly to the copper foil. It is necessary to apply nickel plating, which is a harder substance.

Conventionally, the TAB tape carrier has been subjected to plating at the same time. Therefore, the solder ball mounting portion (land) of the TAB tape carrier is plated with nickel undercoat which is originally unnecessary in view of the improvement in wire bonding property. After that, gold plating was further applied as the outermost layer. In the case of this configuration, generally, nickel plating has a property of easily forming an oxide film, so that the solder melting reaction of gold plating is significantly suppressed, and the solder ball adhesion after long-term thermal aging is reduced.

Therefore, from the viewpoint of avoiding the above disadvantages,
The point of the present invention resides in that gold plating is directly applied to the land without forming the base nickel plating.

In the present invention, the form in which tin plating is applied to the lands instead of gold plating is included. This is to improve the solder ball attachability by forming tin on the lands in advance. . That is, since the solder ball itself is made of an alloy of tin and lead, the lands are plated with tin, which is the same metal, in advance to improve the bondability. It has the same meaning as the so-called "Mukae Handa".

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

<Embodiment 1> FIG. 1A shows a tape carrier (wiring tape for mounting a semiconductor element) according to the first embodiment, and FIG.
(C) is a detailed view of part B.

In this tape carrier, a wiring circuit (copper foil pattern) is formed by copper foil 6 on one side of a polyimide resin film 1 which is an insulating material, and a wire bonding pad 4 for semiconductor connection is formed at one end of the wiring circuit. And a solder ball attachment pad 3 at the other end.
Wiring tape for mounting a semiconductor element on which an insulating film 2 made of solder resist is formed on the wiring circuit surface in the area of the solder ball mounting pad 3 and a connection window hole 5 for wire bonding with the semiconductor element is formed. The carrier has a structure in which Ni / Au plating is applied to the wire bonding pad 4 and Au plating is applied to the solder ball mounting pad 3. That is,
As shown in FIG. 1B, a Ni plating layer 7 is formed as a base layer on the wire bonding pad 4 and an Au plating layer 8 is formed as an upper layer on the Ni plating layer 7. As shown in FIG. An Au plating layer 8 is formed on the ball mounting pad 3.

This tape carrier is manufactured as follows. First, a copper foil 6 is placed on the polyimide resin film 1.
To form a wiring circuit (copper foil pattern), paste a peelable resist film on the copper foil pattern other than the wire bonding pad 4, and apply N to the wire bonding pad 4.
The Ni plating layer 7 is formed by performing i-plating. afterwards,
The resist film is peeled off, and the entire copper foil pattern is plated with Au to form an Au plating layer 8.

According to this tape carrier, only the Au plating layer 8 is formed on the solder ball mounting pad 3. As shown in FIG. 2, in the case where the Ni / Au plating is performed, a predetermined solder ball shear strength cannot be obtained unless the Au concentration is lower than a certain value. The ball joint strength decreases. On the other hand, in the case of only Au plating, a predetermined solder ball shear strength can be obtained even if the Au concentration is not lower than a certain value. Therefore, even if the Au plating thickness is increased, the solder ball bonding strength after the reliability test is reduced. Does not drop. Therefore, the thickness of the Au plating layer 8 of the wire bonding pad 4 can be increased, and good wire bonding properties can be obtained.

<Embodiment 2> FIG. 3A shows a tape carrier according to a second embodiment, in which FIG. 3B is a detailed view of an A portion, and FIG. 3C is a detailed view of a B portion. It is.

In this tape carrier, a wiring circuit (copper foil pattern) is formed with copper foil 6 on one side of a polyimide resin film 1 which is an insulating material, and a wire bonding pad 4 for connecting a semiconductor is formed at one end of the wiring circuit. And a solder ball mounting pad 3 at the other end.
Wiring tape for mounting a semiconductor element on which an insulating film 2 made of solder resist is formed on the wiring circuit surface in the area of the solder ball mounting pad 3 and a connection window hole 5 for wire bonding with the semiconductor element is formed. The carrier has a structure in which Ni / Au plating is applied to the wire bonding pad 4 and Sn plating is applied to the solder ball mounting pad 3. That is,
A Ni plating layer 7 is formed as a base layer on the wire bonding pad 4 as shown in FIG. 3B, and an Au plating layer 8 is formed as an upper layer on the Ni plating layer 7. As shown in FIG. The Sn plating layer 9 is formed on the ball mounting pad 3.

This tape carrier is manufactured as follows. First, a copper foil 6 is placed on the polyimide resin film 1.
To form a wiring circuit (copper foil pattern), paste a peelable resist film on the copper foil pattern other than the wire bonding pad 4, and apply N to the wire bonding pad 4.
By performing i / Au plating, a Ni plating layer 7 as a base layer and an Au plating layer 8 as an upper layer are formed. After that, the resist film is peeled off, a peelable resist film is stuck on the wire bonding pad 4, and Sn plating is performed.
The plating layer 9 is formed.

According to this tape carrier, only the Sn plating layer 9 is formed on the solder ball mounting pad 3, so that good solder ball bonding strength can be obtained. Further, since the thickness of the Au plating layer 8 of the wire bonding pad 4 can be increased, good wire bonding properties can be obtained.

<Embodiment 3> FIG. 4A shows a tape carrier according to a third embodiment, in which FIG. 4B is a detailed view of an A section, and FIG. 4C is a detailed view of a B section. It is.

In this tape carrier, a wiring circuit (copper foil pattern) is formed by copper foil 6 on one side of a polyimide resin film 1 which is an insulating material, and a wire bonding pad 4 for semiconductor connection is formed at one end of the wiring circuit. And a solder ball attachment pad 3 at the other end.
Wiring tape for mounting a semiconductor element on which an insulating film 2 made of solder resist is formed on the wiring circuit surface in the area of the solder ball mounting pad 3 and a connection window hole 5 for wire bonding with the semiconductor element is formed. The carrier has a structure in which a wire bonding pad 4 is plated with Ni / Au and a solder ball mounting pad 3 is plated with solder. That is,
An Ni plating layer 7 is formed as a base layer on the wire bonding pad 4 as shown in FIG. 4B, and an Au plating layer 8 is formed as an upper layer on the Ni bonding layer 7. As shown in FIG. The solder plating layer 10 is formed on the ball mounting pad 3.

This tape carrier is manufactured as follows. First, a copper foil 6 is placed on the polyimide resin film 1.
To form a wiring circuit (copper foil pattern), paste a peelable resist film on the copper foil pattern other than the wire bonding pad 4, and apply N to the wire bonding pad 4.
i / Au plating is performed to form a Ni plating layer 7 as a base layer and an Au plating layer 8 as an upper layer. Thereafter, the resist film is peeled off, a peelable resist film is stuck on the wire bonding pad 4, and solder plating is performed to form a solder plating layer 10.

According to this tape carrier, only the solder plating layer 10 is formed on the solder ball mounting pad 3, so that good solder ball bonding strength can be obtained. Further, since the thickness of the Au plating layer 8 of the wire bonding pad 4 can be increased, good wire bonding properties can be obtained.

According to the embodiment shown in FIGS. 1 to 4, a flex board for BGA having high reliability of solder ball bonding strength and excellent wire bonding property is provided.

When a semiconductor device is constructed using the semiconductor element mounting wiring tape of the above embodiment, a semiconductor element (chip) is mounted on the tape carrier of FIG. 1, FIG. 3 or FIG. The wire bonding pad 4 and the electrode of the semiconductor element are wire-bonded with the gold wire through the window hole 5, and the solder ball is melted and mounted on the solder ball mounting pad 3. Then, the wire bonding portion is sealed with a resin. Thus, a BGA package having high reliability of solder ball bonding strength and excellent wire bonding properties is manufactured.

[0033]

As described above, according to the present invention, the wire bonding pads of the wiring tape carrier for mounting a semiconductor element are plated with Ni / Au, and the pads for attaching the solder balls are plated with Au or Sn. And BGA type tape carrier having high reliability of solder ball bonding strength and excellent wire bonding property, and a BGA type package using the same can be manufactured. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a tape carrier according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between Au plating thickness and solder ball bonding after a reliability test.

FIG. 3 is a diagram illustrating a tape carrier according to a second embodiment of the present invention.

FIG. 4 is a view showing a tape carrier according to a third embodiment of the present invention.

FIG. 5 is a view showing a conventional wiring tape for mounting a semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyimide resin film 2 Insulating film 3 Pad for solder ball attachment 4 Wire bonding pad 5 Window part 6 Copper foil (copper foil pattern) 7 Ni plating layer 8 Au plating layer 9 Sn plating layer 10 Solder plating layer

Continuation of the front page (72) Inventor Hiroshi Sugimoto 5-1-1, Hidaka-cho, Hitachi-shi, Ibaraki F-term in Hitachi Cable, Ltd. General Research Laboratory 5F044 AA03 MM04 MM13 MM23 MM31

Claims (4)

[Claims] A wiring circuit is formed of copper foil on one side of an insulating film, a wire bonding pad for connecting a semiconductor is formed at one end of the wiring circuit, and a solder ball mounting pad is formed at the other end. In the wiring tape carrier for mounting a semiconductor element, a Ni plating layer was formed as a base layer on the wire bonding pad, an Au plating layer was formed thereon, and an Au plating layer was formed on the solder ball mounting pad. A tape carrier, characterized in that: 2. A wiring circuit is formed from copper foil on one side of an insulating film, a wire bonding pad for connecting a semiconductor is formed at one end of the wiring circuit, and a solder ball mounting pad is formed at the other end. In the wiring tape carrier for mounting a semiconductor element, a Ni plating layer was formed as a base layer on the wire bonding pad, an Au plating layer was formed as an upper layer, and a Sn plating layer was formed on the solder ball mounting pad. A tape carrier, characterized in that: 3. A wiring circuit is formed of copper foil on one surface of an insulating film, a wire bonding pad for connecting a semiconductor is formed at one end of the wiring circuit, and a solder ball mounting pad is formed at the other end. In the wiring tape carrier for mounting a semiconductor element, a Ni plating layer was formed as a base layer on the wire bonding pad, an Au plating layer was formed thereon, and a solder plating layer was formed on the solder ball mounting pad. A tape carrier, characterized in that: 4. The tape carrier according to claim 1, wherein a semiconductor element is mounted on the tape carrier, and an electrode of the semiconductor element and a wire bonding pad are wire-bonded with a gold wire. A semiconductor device wherein solder balls are melt-mounted on solder ball mounting pads.