JPH0888305A - Manufacture of lead frame - Google Patents

Abstract

PURPOSE: To obtain a lead frame which reduces the number of manufacturing processes and to which a fine working operation can be performed at low costs. CONSTITUTION: An electrodeposition roller 11 whose surface is provided with insulating protrusions 12 in a pattern whose shape is opposite to that of a lead frame is turned in a plating tank 13 in which a plating liquid 4 has been put. A current is made to flow to the electrodeposition roller 11 through an anode 15 and a power-supply roller 16. A metal is electrodeposited on the surface of the electrodeposition roller 11. When a plated film which has been formed in this manner is stripped from the electrodeposition roller 11, a copper foil 17 in which a pattern for the lead frame has been formed is manufactured, and the lead frame is manufactured by using the copper foil. Thereby, the formation and etching process of a resist pattern as a process which is indispensable for a manufacturing method after the bonding operation of a metal foil can be eliminated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to Tape A for semiconductors.
The present invention relates to a method for manufacturing a lead frame of electrolytic metal foil used for automated bonding (hereinafter referred to as TAB tape), a printed wiring board and the like.

[0002]

2. Description of the Related Art Conventionally, a lead frame on which a semiconductor element is mounted is generally formed by stamping or etching a metal plate having a thickness of 0.1 to 0.3 mm by stamping or etching. , As the demand for narrow pitch increases, electroforming by additive plating or TAB tape (or TCP: Tap)
A method of forming a fine pattern by processing a metal foil, such as eCarrier Package, has been used.

In particular, the TAB tape is the most widely used as a construction method capable of reducing the thickness of the package as well as the finest processing among the methods currently used.

A conventional method for producing a lead frame will be described below. As shown in FIG. 6, a polyimide tape 1 with an adhesive is punched for mounting semiconductors and for external connection of a printed circuit board or the like, and then a metal foil 2 is bonded onto the polyimide tape 1. In this case, the metal foil 2 is a flat plate having an uneven surface on the surface to be bonded to the polyimide tape 1 and a smooth surface on the opposite surface. A resist 3 for forming a pattern is formed on the metal foil 2.
Is coated, exposed and developed to form a frame pattern. The surface of the metal foil patterned in this way is etched to form wiring, the resist 3 is removed, and a necessary portion is plated to form a TAB tape 4. The electrolytic metal foil 2 used in the manufacturing method of such a TAB tape is manufactured by the manufacturing equipment as shown in FIG. That is, a current is passed from the anode 7 to the power feeding roller 8 to the smooth surfaced electrodeposition roller 6 that is slowly rotating in the plating solution 5, and the metal to be electrodeposited on the surface of the electrodeposition roller 6 is taken up by the winding roller 9. The metal foil 10 is made by winding the metal foil 10. At this time, the thickness of the metal foil 10 to be electrodeposited is determined by the electrodeposition roller 6
Control by adjusting the rotation speed of. The flat metal foil 10 thus formed is cut into a certain width and TA
Used as the metal foil 2 for B tape.

[0005]

However, as described above, it takes a lot of man-hours to manufacture a lead frame using a metal foil such as a TAB tape, and the processing time in each step is long, so that the material for the process is long. Since the cost is also high, the low productivity which is caused is a constraint, and there is a problem that only a part of the lead frame is used.

The present invention solves the above-mentioned conventional problems. The metal foil used for the TAB tape or the like is not a flat plate as in the conventional case, but is a metal foil formed by electrodeposition of a lead frame pattern. To provide a method for manufacturing a lead frame capable of reducing the number of steps while maintaining the fine processing without the formation / etching of a resist pattern, which is a step that is indispensable for the manufacturing method after adhesion of the metal foil. With the goal.

[0007]

In order to achieve this object, a method of manufacturing a lead frame according to the present invention comprises a surface of an electrodeposition roller for electrodepositing a metal foil, which has an insulation property of a pattern opposite to the pattern of the lead frame. It has a structure with a protrusion.

[0008]

With this structure, by depositing metal on the surface of the electrodeposition roller, a metal foil having the lead frame pattern can be continuously formed, and the processing of the metal foil is eliminated in the subsequent steps, resulting in a significant reduction in the number of steps. Can be achieved.

[0009]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is a cylindrical electrodeposition roller made of stainless steel, and copper is electrodeposited on the surface of the electrodeposition roller 11. Reference numeral 12 is a projection made of an insulating member provided on the surface of the electrodeposition roller 11, and the projection 12 has a pattern shape opposite to the pattern of the lead frame and has a thickness of 20 to 100 μm. In the case of this embodiment, 50 μm
And 13 is a plating tank, and a plating solution 14 is contained in the plating tank 13.
It is a copper plating solution composed of 250 g / L and sulfuric acid of 30 to 200 g / L. In the case of this embodiment, copper sulfate is 200 g /
A copper plating solution containing L and sulfuric acid at 50 g / L was used. Reference numeral 15 denotes an anode arranged in the plating tank 13 so as to face the electrodeposition roller 11 with a distance of 5 to 50 mm, and a positive potential is applied to the anode 15. Reference numeral 16 is a power feeding roller made of a stainless steel material. The power feeding roller 16 is in contact with the electrodeposition roller 11, and a predetermined current flows from the anode 15 to the electrodeposition roller 11. Reference numeral 17 is a copper foil on which a lead frame pattern is formed, and 18 is a winding roller for winding the copper foil 17. Three
Reference numeral 0 denotes an outlet for sucking up the plating solution 14 with a pump (not shown) and pouring it between the electrodeposition roller 11 and the anode 15, whereby the plating solution 14 is agitated to make the concentration of the plating solution 14 uniform. The electrodeposition speed of the copper foil 17 can be increased.

The operation of the electrodeposition apparatus constructed as above will be described. When the plating solution 14 is put in the plating tank 13 and electric current is passed through the anode 15 and the power feeding roller 16 while rotating the electrodeposition roller 11 at a speed of 0.005 to 0.1 rpm,
Copper having a thickness of 35 to 38 μm is electrodeposited on the conductive portion on the surface of the electrodeposition roller 11. By peeling off the copper plating film thus deposited from the electrodeposition roller 11, the copper foil 17 on which the lead frame pattern is formed is taken up by the take-up roller 18. The thickness of the copper foil 17 to be electrodeposited is controlled by controlling the rotation speed of the electrodeposition roller 11 and the value of the current flowing through the anode 15 and the power feeding roller 16.

In this embodiment, a copper plating solution is used as the plating solution 14, but the plating solution 14 is mainly composed of nickel sulfamate of 500 g / L in order to increase the strength of the metal foil. With liquid, or
Needless to say, an iron plating solution containing 400 g / L of iron sulfate, 50 g / L of sodium chloride and 30 g / L of aquatic acid may be used.

FIG. 2 shows the copper foil frames 19a and 19b, which are processed into a predetermined pattern according to the purpose of use.
In other words, when using it for TAB tape,
The copper foil frame 19a having a frame pattern linearly arranged as shown in (a) is used, and when it is used for a printed wiring board, as a copper foil frame 19b having a matrix frame pattern as shown in FIG. 2 (b). To process.
Further, since the metal foil frame has a thin thickness of 10 to 50 μm, frames 20a and 20b are provided around the copper foil frames 19a and 19b for reinforcement and supply of electric current for electroplating performed in a later step. ing. Further, as a deformation prevention, a bridging pattern 21 for connecting the leading ends of the metal foil leads may be provided as shown in FIG.

As shown in FIG. 4, this copper foil frame 19a is laminated on a polyimide film 22 with an adhesive which has been punched for mounting semiconductor elements and punched for punching external connection of a printed circuit board or the like. Part,
For example, the wire bonding portion for connecting the semiconductor element with the wire is plated with gold, and the connection portion with the outer lead is plated with gold, tin, or solder plating, etc.
The tape 23 is produced.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to the drawings. Copper foil frame 19b
The process up to the step of manufacturing is the same as that of the first embodiment, and thus will be omitted. In FIG. 5, the copper foil frame 19b is laminated on the printed circuit board 24 with an adhesive to form the copper foil frame 1
Printed wiring board 26 having wiring layer 25 made of 9b
Is prepared. Next, a required portion of the wiring layer 25, for example, a wire bonding portion for connecting the semiconductor element with a wire is plated with gold, and a connecting portion with the outer lead is covered with gold, tin,
Alternatively, after plating such as solder plating is performed to produce a plated printed wiring board 27, the plated printed wiring board 27 is cut to produce an inner pattern 28 for a lead frame.

[0015]

As described above, according to the present invention, processing steps such as resist patterning and etching which are necessary in the usual manufacturing of a TAB tape or a printed wiring board are not necessary, and the number of steps can be reduced. Further, in the conventional TAB tape manufacturing method, the processing capacity of the exposure step becomes a bottleneck and the production capacity is limited.
Mass production is possible. Furthermore, since the metal foil is produced by electrodeposition, the cross-sectional shape is rectangular. Therefore, compared with the etching method which is a normal manufacturing method, there is also an effect that the sagging of the side surface peculiar to etching is eliminated and the accuracy of the pattern interval is improved, and the present invention is an excellent lead frame capable of performing fine processing at low cost. Is a manufacturing method.

[Brief description of drawings]

FIG. 1 is a sectional view of an electrodeposition apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of a copper foil frame according to the first embodiment of the present invention.

FIG. 3 is a plan view of a copper foil frame according to the first embodiment of the present invention.

FIG. 4 is an explanatory view showing a TAB tape manufacturing process in the first embodiment of the present invention.

FIG. 5 is an explanatory view showing a printed wiring board manufacturing process according to the second embodiment of the present invention.

FIG. 6 is an explanatory view showing a conventional TAB tape manufacturing process.

FIG. 7 is a sectional view of a conventional electrodeposition apparatus for producing metal foil.

[Explanation of symbols]

 11 Electrodeposition roller 12 Protrusion 13 Plating layer 14 Plating liquid 15 Anode 16 Power supply roller 17 Copper foil 18 Winding roller 19a, 19b Copper foil frame 20a, 20b Frame 21 Crossover pattern 22 Polyimide film 23 TAB tape 24 Printed circuit board 25 Wiring layer 26 Printed wiring board 27 Plated printed wiring board 28 Inner pattern 30 Blowout port

Claims (5)

[Claims] 1. A method comprising: providing a plurality of insulating protrusions on the surface of an electrodeposition roller; depositing metal along the protrusions of the electrodeposition roller to produce a metal foil; and attaching the metal foil to a substrate. Characteristic lead frame manufacturing method. 2. The method for manufacturing a lead frame according to claim 1, wherein the shape of the protrusions provided on the surface of the electrodeposition roller is a shape of a pattern opposite to a predetermined pattern of the lead frame. 3. A plurality of insulating projections are provided on the surface of an electrodeposition roller, a metal is deposited along the projections of the electrodeposition roller to produce a metal foil, and the metal foil is bonded to a polyimide tape. A method of manufacturing a lead frame, characterized in that the lead frame is in a Tape Automated Bonding shape. 4. A plurality of insulating protrusions are provided on the surface of the electrodeposition roller, a metal is deposited along the protrusions of the electrodeposition roller to produce a metal foil, and the metal foil is bonded to a printed circuit board. And a printed wiring lead frame. 5. The method of manufacturing a lead frame according to claim 1, wherein the metal to be electrodeposited is copper, nickel or iron as a main component.