JPH10223696A - Tab tape and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid damage to leads due to electroless plating by providing a thicker Sn plated layer on ball pad leads than an Sn plated layer on inner leads. SOLUTION: An alkanol sulphonate electroless plating liq. is applied to form an Sn plated layer of 0.4μm on a resist surface as a plated part 6b. After removing a plating resist, a photo resist is applied to a ball pad-forming surface, exposed to form a wiring pattern 3, developed, coated with a backing agent, and etched to form a wiring pattern, inner leads 4 and ball pad leads 6a. An insulative protection paint is applied to the entire surface from the outside of the ball pad part 6 to the inside of a device hole 3 and heated at 150 deg.C for 60min. Using an electroless plating liq. an Sn plating is applied to form plated inner leads of 0.4μm thick. From evaluated results it is verified that the inner leads are 0.2μm thick and Sn plated layer on ball pad part 6 is 0.5μm thick.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a T
The present invention relates to an AB tape and a method for manufacturing the same, and more particularly, to a TAB tape having different plating thicknesses or different types of plating in a wiring pattern and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 1 shows a TAB (TaB) used for a semiconductor device.
pe Automated Bonding) tape. As shown in the figure, a sprocket hole 1 for carrying and positioning a semiconductor element (IC chip) in a mounting process of a semiconductor element (IC chip) is formed on both sides of an insulating film 2, and a semiconductor element is accommodated in a central portion. A device hole 3 having a rectangular opening is formed. This device hole 3
Vertically from each piece of device hole 3 toward the center of
Further, inner leads 4 protruding at regular intervals are formed on the insulating film 2.

[0005] The other end of the inner lead 4 is connected to a wiring pattern 5 wired on the insulating film 2. At the other end of the wiring pattern 5, a circular ball pad 6
Is provided. Insulating protective paint 7 is applied to the entire area of the ball pad portion 6 near the device hole 3 except for the area where the solder balls are provided, including the wiring pattern 5 and the inner leads 4 and most of the area. I have.

[0004] As the insulating protective coating 7, a coating that can withstand heating during packaging and ball formation is used. The inner leads 4, the wiring patterns 5, and the ball pad portions 6 are formed by etching a copper foil.

On one side of the semiconductor element, an inner lead 4
A pad connected to the tip of the inner lead 4 is provided at a predetermined position. The semiconductor element is positioned so as to cover the device hole 3 while aligning the pad with the tip of the inner lead 4. Glue to the back with adhesive. Thereafter, the inner leads 4 and the pads of the semiconductor element are bonded to each other.

FIG. 2 shows details of the ball pad section 6.
It has a circular ball pad lead 6a formed so as to be connected to the end of the wiring pattern 5, and a plating portion 6b provided concentrically on the ball pad lead 6a.
A solder ball (not shown) is provided on the plating portion 6b, and connection with a substrate or the like is performed.

FIG. 3 shows a cross section of the ball pad portion 6,
The insulating protection material 7 is applied so as to leave the plated portion 6b. The plated portion 6b is plated with tin having a thickness of 0.4 μm or more in order to improve the bonding with a solder ball (not shown). The inner lead 4 has a thickness of 0.2 μm for good bonding with the pad of the semiconductor element.
m of tin plating is applied.

FIGS. 4A to 4G show a method of manufacturing this TAB tape. Hereinafter, the procedure for manufacturing the TAB tape will be described with reference to FIGS. 4A to 4G while also referring to FIGS. (1) First, an adhesive 10 is applied to one surface of the insulating film 2 and punched for a device hole to form a punched hole 11, and then a laminated copper foil tape 12 is applied to a surface to which the adhesive 10 is applied by a hot roller. (Fig. 4
(A)). (2) Next, a photoresist 13 for forming a pattern or a lead is applied to the adhered laminated copper foil tape 12 (FIG. 4B), and exposure and development are performed (FIG. 4 (B)). c)). (3) After exposure and development, a backing agent 14 is applied (FIG. 4).
(D)), inner leads 4 by photo-etching
After forming the wiring pattern 5 and the ball pad leads 6a (FIG. 4E), the unnecessary photoresist 13 is peeled off from the laminated copper foil tape 12 (FIG. 4).
(F)). (4) Then, an insulating protective paint 7 is applied except for the tip of the inner lead 4 and the portion of the ball pad lead 6a (FIG. 4 (g)), and is heated and dried at a predetermined temperature for a predetermined time. (5) After drying, the tip of the inner lead 4 is masked, and a predetermined portion on the ball pad lead 6a is tin-plated with an electroless tin plating solution to form a plated portion 6b. (6) Thereafter, the masking provided at the tip of the inner lead 4 is removed, tin plating is applied to this portion and the plating portion 6b, and heating is performed at a predetermined temperature for a predetermined time. Thus, the TAB tape is completed.

As is apparent from the above description, the conventional T
According to the method of manufacturing the AB tape, the tinning is applied twice to the ball pad portion 6. That is, the first tin plating is performed on the plated portion 6b of the ball pad portion 6 after the inner lead 4 is masked, and the second tin plating is performed on the plated portion 6b of the inner lead 4 and the ball pad portion 6 after removing the masking. Tin plating is performed.

[0010]

According to the conventional TAB tape manufacturing method, however, tin plating is applied twice to the plated portion 6b. This tin plating is performed using an electroless tin plating solution. Therefore, there is a problem in the reliability of the ball pad portion.

That is, as a characteristic of the electroless tin plating solution, there is a property of dissolving copper, and the copper foil at the interface with the insulating protective paint may be damaged. The damage increases as the time of immersion in the tin plating solution increases. A long time immersion is required for thick tin plating. According to the conventional method of manufacturing a TAB tape, the ball pad portion is immersed twice in the tin plating solution, so that a plating time twice or more as long as the plating of the inner lead is required. This time is such that damage is not negligible.

The fact that copper is damaged means that a gap 8 as shown in FIG. 5 is formed at the interface between the copper foil and the insulating protective paint. The formation of the gap 8 adversely affects the shape of the ball and the consistency with the tape, and impairs the reliability. In addition, even if thorough cleaning is performed, there is a risk to reliability, and a detailed inspection is required.

In addition, after the wiring pattern is formed, a portion which must not be subjected to the first plating must be masked with a resist, so that the lead of the punching hole may be deformed.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a TAB tape and a method for manufacturing the same, which can prevent lead damage due to electroless tin plating and prevent deformation of punched hole leads due to masking. To provide.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a TAB having an inner lead connected to a semiconductor chip and a ball pad lead connected to another electric conductor by solder balls or the like. In the tape, the inner lead and the ball pad lead have a tin plating layer on a surface, and the tin plating layer of the ball pad lead has a thickness larger than that of the inner lead. A TAB tape is provided.

According to another aspect of the present invention, there is provided a TAB tape having an inner lead connected to a semiconductor chip and a ball pad lead connected to another electric conductor by solder balls or the like. The inner lead has a tin plating layer on the surface, and the ball pad lead has a gold plating layer on the surface. In this case, the gold plating layer may have a tin plating layer on the surface.

Further, in order to achieve the above object, the present invention provides a method in which a plating resist is applied to a surface of a copper foil laminated on an insulating film having a device hole except for a portion where a ball pad is formed, and Forming a tin plating layer, removing the plating resist, applying a photoresist, performing exposure of wiring leads connecting the inner leads and the ball pad portion including the ball pad forming portion, and performing development and etching. Forming an inner lead, the ball pad portion, and the wiring lead, applying an insulating protective paint except for the inner lead and the tin plating layer, and applying tin plating to the inner lead and the tin plating layer. TA
A method of manufacturing a B tape is provided.

Further, in order to achieve the above object, the present invention provides a method of forming a ball pad on a surface of a copper foil laminated on an insulating film having device holes, except for applying a plating resist except for a ball pad forming portion. A gold plating layer is formed on the portion, the plating resist is removed, a photoresist is applied, a wiring lead for connecting an inner lead and a ball pad portion including the ball pad forming portion is exposed, and development and etching are performed. To form the inner leads, the ball pad portions, and the wiring leads, apply an insulating protective paint except for the inner leads and the gold plating layer, and mask the gold plating layer or not. And a method for producing a TAB tape characterized by applying tin plating to a TAB tape.

[0019]

Embodiments of the present invention will be described below. In the present invention, the plating portions of the inner leads and the ball pad leads are plated with tin as in the past, but the plating portions of the ball pad leads may be plated with gold instead of tin plating. Since gold plating is excellent in solder wettability, conductivity, corrosion resistance, and the like, a ball pad such as a solder ball can be provided with high reliability.

[0020]

Next, a TAB tape of the present invention and a method for manufacturing the same will be described. The shape of the TAB tape is shown in Figs.
This is as shown in FIG. [Embodiment 1] First, a description will be given of a manufacturing method in the case of plating the inner lead 4 and the plated portion 6b of the ball pad lead 6a with tin. (1) A plating resist is applied to the surface of the copper foil laminated on one side of the insulating film 2. This plating resist is applied by printing, and is applied to the entire surface of the ball pad lead 6a except for the portion corresponding to the plating portion 6b. (2) Tin plating of 0.4 μm thickness is performed on the resist surface with an alkanolsulfonic acid-based electroless tin plating solution to form a plated portion 6b. (3) The plating resist applied in (1) is removed. (4) A photoresist is applied to the surface on which the ball pad portion 6 has been formed in (1), and exposure for forming the wiring pattern 5 is performed. (5) After the exposure according to (4), development, application of a backing agent, and etching are sequentially performed to form each of the wiring pattern 5, the inner lead 4, and the ball pad lead 6a. (6) An insulating protective paint is applied to the entire surface (excluding the tin-plated portion) from the outside of the ball pad portion 6 to the inside of the device hole 3, and heated at 150 ° C. for 60 minutes. (7) Using the electroless tin plating solution of the above (2), tin plating is performed so that the inner lead 4 has a thickness of 0.4 μm. (8) Heat at 130 ° C. for 90 minutes to prevent whiskers.

The TAB tape manufactured as described above was evaluated. As a result, the inner lead was 0.2
The cross-sectional photograph confirmed that the thickness of the ball pad portion 6 was 0.4 μm and the thickness of the tin plating was 0.4 μm. In addition, it was confirmed that there was no damage by the plating solution on the interface between the insulating protective paint of the ball pad portion 6 and the tin plating.

[Embodiment 2] Next, a manufacturing method in which the inner lead 4 is plated with tin and the plated portion 6b is plated with gold will be described. (1) A plating resist is applied to the surface of the copper foil laminated on one side of the insulating film 2. This plating resist is applied by printing, and is applied to the entire surface of the ball pad lead 6a except for the portion corresponding to the plating portion 6b. (2) After applying 0.2 μm-thick electric nickel plating to the resist surface with a sulfanilic acid-based nickel plating solution, 1 μm-thick electrogold plating is applied to the surface of this electric nickel plating with a cyan-based gold plating solution. The plating part 6b is formed. (3) The plating resist applied in (1) is removed. (4) A photoresist is applied to the surface on which the ball pad portion 6 has been formed in (1), and exposure for forming the wiring pattern 5 is performed. (5) After the exposure according to (4), development, application of a backing agent, and etching are sequentially performed to form each of the wiring pattern 5, the inner lead 4, and the ball pad lead 6a. (6) An insulating protective paint is applied to the entire surface (except for the gold-plated portion) from the outside of the ball pad portion 6 to the inside of the device hole 3, and heated at 150 ° C. for 60 minutes. The application of the insulating protective paint to the ball pad lead 6a is performed by the plating portion 6b.
And may partially overlap. (7) A plating resist is applied to the gold-plated portion in the above (6) by screen printing. (8) Using an electroless tin plating solution, tin plating is performed so that the inner leads 4 have a thickness of 0.4 μm, and then the plating resist is removed. (8) Heat at 130 ° C. for 90 minutes to prevent whiskers.

In the second embodiment, the plating resist is applied to the gold-plated portion and tin plating is applied to the inner lead 4. However, the plating resist is not applied to the gold-plated portion but is applied together with the inner lead 4. Tin plating may be applied also to the gold plating portion.

The TAB tape manufactured as described above was evaluated. As a result, the inner lead 4 is set at 0.
2 μm thick tin plating, ball pad 6 0.4 μm
The cross-sectional photograph confirmed that the gold plating thickness was m. Also, it was confirmed that there was no damage by the plating solution at the interface between the insulating protective paint of the ball pad portion 6 and the gold plating.

In the above embodiments, various descriptions have been made on the TAB tape and the method of manufacturing the same, but it goes without saying that the present invention is not limited to this. For example, a BGA (Ball Grid Allay) tape that can be plated beforehand with a necessary portion before forming a wiring pattern, and with or without a pre-plated portion after forming the wiring pattern and its The present invention can be applied to a manufacturing method.

[0026]

As described above, according to the TAB tape and the method of manufacturing the same of the present invention, the electroless tin coating after the application of the insulating protective coating is performed once, and the insulating protective coating is applied. Since the masking step after this is omitted, it is possible to prevent the lead from being damaged due to the electroless tin plating and to prevent the lead of the punched hole from being deformed due to the masking. As a result, a highly reliable TAB tape and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing a TAB tape.

FIG. 2 is a plan view showing details of a ball pad unit in FIG. 1;

FIG. 3 is a cross-sectional view of the ball pad section of FIG. 2;

FIG. 4 is a diagram showing a method of manufacturing a TAB tape.

FIG. 5 is a view showing a state in which an interface between the insulating protective paint of the ball pad portion of FIG. 3 and a ball pad lead is damaged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sprocket hole 2 Insulating film 3 Device hole 4 Inner lead 5 Wiring pattern 6 Ball pad part 6a Ball pad lead 6b Plating part 7 Insulating protective paint 8 Damage 10 Adhesive 11 Punching hole 12 Laminated copper foil tape 13 Photoresist 14 Back Stopper

Claims (5)

[Claims] 1. A TAB tape having an inner lead connected to a semiconductor chip and a ball pad lead connected to another electric conductor by solder balls or the like, wherein the inner lead and the ball pad lead are tin-plated on the surface. The TAB tape according to claim 1, wherein the tin plating layer of the ball pad lead has a thickness greater than that of the tin plating layer of the inner lead. 2. A TAB tape having an inner lead connected to a semiconductor chip and a ball pad lead connected to another electric conductor portion by a solder ball or the like, wherein the inner lead has a tin plating layer on a surface, A TAB tape, wherein the ball pad lead has a gold plating layer on a surface. 3. The TAB tape according to claim 2, wherein the gold plating layer has a tin plating layer on a surface. 4. A plating resist is applied to a surface of a copper foil laminated on an insulating film having a device hole except for a ball pad forming portion, a tin plating layer is formed on the ball pad forming portion, and the plating resist is removed. Then, a photoresist is applied, and a wiring lead for connecting the inner lead and the ball pad portion including the ball pad forming portion is exposed. The inner lead, the ball pad portion, and the wiring lead are developed and etched. A method for producing a TAB tape, comprising: forming an insulating protective coating except for the inner leads and the tin plating layer; and applying tin plating to the inner leads and the tin plating layer. 5. A plating resist is applied to a surface of a copper foil laminated on an insulating film having a device hole except for a ball pad forming portion, a gold plating layer is formed on the ball pad forming portion, and the plating resist is removed. Then, a photoresist is applied, and a wiring lead for connecting the inner lead and the ball pad portion including the ball pad forming portion is exposed. The inner lead, the ball pad portion, and the wiring lead are developed and etched. Forming a TAB tape characterized by applying an insulating protective paint except for the inner leads and the gold plating layer, and masking the gold plating layer or applying tin plating without masking Method.