JP2002093943A - Manufacturing method and device of film carrier tape for mounting electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method and device of a film carrier tape for mounting electronic components that uses a conductive metal ball such as a soldering ball as an external connection terminal, cannot easily eliminate the conductive metal ball, has excellent durability, and can be reliably and electrically connected. SOLUTION: By current-controlling devices for surface and rear electrodes, current flowing between the surface of a film carrier tape and the surface electrode is set larger than current flowing between the rear of the carrier tape and the rear electrode, and plating thickness (a) of a gold-plated layer that is electrolytically deposited on the surface of a connection terminal at the electronic-component side of the film carrier tape is set thicker than that (b) of the gold-plated layer that is electrolytically deposited at an external terminal connection section joined to the conductive metal ball on the back surface of the film carrier tape for forming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a device on one surface of a flexible insulating film, and forming a metal-containing conductive material such as a solder ball on the back surface of the flexible insulating film on which the device is mounted. Film carrier tape for electronic component mounting, in which conductive balls are arranged, and these metal-containing conductive balls are used as external connection terminals of a device on which the metal-containing conductive balls are mounted, particularly
The present invention relates to a manufacturing method and a manufacturing apparatus for manufacturing a CSP (Chip Size Package).

[0002]

2. Description of the Related Art Conventionally, various methods have been adopted for incorporating electronic components into an actual electronic device. Among them, a device hole is formed in an insulating film slightly larger than an electronic component to be mounted. A method of extending an inner lead from the edge of the device hole into the device hole and connecting the inner lead to an electrode formed on an electronic component has been adopted. The use of the electronic component mounting film carrier tape having the device holes as described above requires the external connection terminals to be formed at the peripheral edge of the electronic component, and the mounting density of the electronic component in the electronic device does not become higher than a certain level. is there.

In recent years, there has been a strong demand for lighter and smaller electronic devices, and in the case of conventional film carrier tapes for mounting electronic components, which have device holes and external connection terminals are extended around the periphery, as described above. It is becoming increasingly difficult to satisfy the demand for smaller and lighter electronic devices. Therefore, a method of arranging external connection terminals on the back surface of the electronic component to be mounted has been devised. Since a film carrier used in this method has a size substantially equal to that of the electronic component, a CS is required.
P (Chip Size Package), already FBGA (Finepit
ch Ball Grid Array).

FIGS. 1 and 2 show such a method.
The following two types of film carrier tapes for mounting electronic components are employed. That is, a conductive metal foil such as a copper foil is etched on one surface of the flexible insulating film 11 to form a wiring pattern 14, and a gold plating layer 36 is formed on the surface of the electronic component side connection terminal 34 of the wiring pattern 14. Is formed.

In the type shown in FIG. 1, a bump electrode 51 formed on the upper surface of an electronic component (device) 50 and an electronic component side connection terminal 34 are connected to each other by a conductive metal wire 33 such as a gold wire. By bonding, the electronic component 50 is mounted on the film carrier. In the type of FIG. 2, the bump electrodes 51 and the electronic component side connection terminals 34 formed on the lower surface of the electronic component 50 are formed on the lower surface of the electronic component 50 while cutting the electronic component side connection terminals 34. The electronic component is mounted on the film carrier by directly bonding to the bump electrode 51.

On the other hand, the electronic component side connection terminal 34 is
Flexible insulating film 1 on the lower surface of mounted electronic component 50
The wiring is formed so as to cover the through-hole (external connection terminal hole) 21 formed in the first through-hole 1. Then, the flexible insulating film 11
A metal-containing conductive ball 20 is arranged in an external connection terminal hole 21 formed on the substrate to electrically connect the metal-containing conductive ball 20 and the wiring pattern 14, and a back surface of the flexible insulating film 11. Thus, the metal-containing conductive balls 20 are exposed, and the metal-containing conductive balls 20 exposed on the back surface are used as external connection terminals.

[0007] As the metal-containing conductive balls 20 used as external terminals in such a film carrier tape for mounting electronic components, solder balls are mainly used.

[0008]

As described above, the electronic component 5
In order to bond with the bump electrode 51 provided on the electronic component side connection terminal 34, a gold plating layer 3
6 need to be formed. For this reason, the film 1 on which a large number of wiring patterns 14 are formed is subjected to a gold plating process.
1 is passed through a gold plating bath in which electrodes are arranged, and a current is applied to the exposed wiring pattern 1
The method of plating the surface of No. 4 with gold is adopted. Therefore, the gold plating layers 34 and 37 having a substantially uniform thickness are formed on the exposed surface of the wiring pattern 14.

The wiring pattern 14 thus exposed
The wiring pattern 14 in which the gold plating layer 36 having a uniform thickness is formed on the surface of the
1 and a very good electrical connection can be formed.
However, between the solder ball used as the conductive metal ball 20 and the wiring pattern 14, if gold exists on the surface of the wiring pattern 14, a gold-solder alloy is formed and joined. This gold-solder alloy has a characteristic that, for example, when the ratio of gold in the solder exceeds 4%, the impact value is sharply reduced, and the alloy becomes very hard and brittle. Therefore, if the gold-solder alloy is excessively present on the joint surface between the solder ball 20 and the wiring pattern 14, that is,
When the thickness of the gold plating layer 37 formed on the back surface of the wiring pattern 14 forming the bottom (closed end) of the external connection terminal hole 21 increases, the shear strength of the solder ball 20 decreases, and the solder ball 20 It becomes easy to fall off from the pattern 14.

This tendency is caused by cutting the wiring pattern 14 formed so as to straddle the slit 31 as shown in FIG. 2 and directly connecting the bump electrode 51 formed on the bottom edge of the electronic component (IC) 50. This also occurs in the case of a film carrier tape for mounting electronic components of the beam lead bonding type which is welded to (usually made of gold). Such dropping of the solder balls 20 means that the film carrier loses the external connection terminals, and the dropped solder balls 20 are inserted into the external connection terminal holes 21 for the solder balls formed in the insulating film 11 again, and the solder balls are again removed. 20 must be embedded. This repair work is very complicated, and has become a very serious problem in a film carrier in which an external connection terminal is formed using a conductive metal ball like a CSP.

Further, the cost of the film carrier is increased by forming an excessively thick gold plating layer. The present invention is a film carrier using a conductive metal ball such as a solder ball as an external connection terminal in consideration of such a current situation, and the conductive metal ball is not easily detached, and has excellent durability. It is an object of the present invention to provide a method of manufacturing a film carrier tape for mounting electronic components capable of ensuring reliable electrical connection and a manufacturing apparatus therefor.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned objects and objects of the prior art, and a method of manufacturing a film carrier tape for mounting electronic parts according to the present invention is described below. An insulating film, having a wiring pattern formed on one surface of the insulating film, at one end of the wiring pattern is formed an electronic component side connection terminal connectable to an electronic component to be mounted, At the other end of the wiring pattern, an external terminal joining portion formed on a through hole formed in the insulating film is formed, and a side opposite to the surface of the insulating film on which the wiring pattern is formed. By disposing a conductive metal ball in the through hole, the conductive metal ball is formed on the back surface of the insulating film and on the surface of the insulating film via the conductive metal ball. A method for manufacturing an electronic component mounting film carrier tape configured to be capable of electrical connection with an electronic component electrically connected to the wiring pattern, wherein the one surface of the insulating film is provided. A film carrier tape having a wiring pattern formed thereon is immersed in a gold plating bath, separated by a predetermined distance so as to face the surface of the film carrier tape, and a surface electrode is arranged in the gold plating bath, and the film carrier tape is provided. A predetermined distance is provided so as to face the back surface of the tape, a back electrode is disposed in a gold plating bath, a current flowing between the front surface and the front electrode of the film carrier tape, and a back surface and a back surface of the film carrier tape are provided. By individually controlling the current flowing between the electrodes, the current flowing between the surface of the film carrier tape and the surface electrode, The current flowing between the back surface and the back surface electrode of the film carrier tape is set to be larger than that of the film carrier tape, and the plating thickness (a) of the gold plating layer electrolytically deposited on the surface of the electronic component side connection terminal of the film carrier tape is reduced. It is characterized in that it is formed so as to be thicker than the plating thickness (b) of the gold plating layer electrolytically deposited on the external terminal connecting portion to be joined to the conductive metal ball on the back surface of the carrier tape.

[0013] Further, an apparatus for manufacturing a film carrier tape for mounting electronic parts according to the present invention has an insulating film and a wiring pattern formed on one surface of the insulating film, and one end of the wiring pattern is provided at one end of the wiring pattern. An electronic component-side connection terminal connectable to an electronic component to be mounted is formed, and an external terminal joint formed on a through-hole formed in the insulating film is formed at the other end of the wiring pattern. In addition, by arranging conductive metal balls in the through holes from the side opposite to the surface of the insulating film on which the wiring pattern is formed, the conductive metal balls are interposed between the conductive metal balls and on the back surface of the insulating film. An electronic component mounting film configured to be electrically connectable to an electronic component electrically connected to a wiring pattern formed on a surface of the insulating film. A manufacturing apparatus for manufacturing a carrier tape, a gold plating bath for immersing a film carrier tape having a wiring pattern formed on one surface of the insulating film, and a predetermined distance so as to face the surface of the film carrier tape. Separated, the front electrode disposed in the gold plating bath, and separated by a predetermined distance so as to face the rear surface of the film carrier tape, the back electrode disposed in the gold plating bath, and the film carrier tape A current flowing between the front surface and the front electrode, and a current control device for the front electrode and a current control device for the back electrode individually controlling the current flowing between the back surface and the back electrode of the film carrier tape, By the current control device for the front electrode and the current control device for the back electrode, the current flows between the front surface of the film carrier tape and the front electrode. The current is made larger than the current flowing between the back surface and the back electrode of the film carrier tape, and the plating thickness of the gold plating layer electrolytically deposited on the surface of the electronic component side connection terminal of the film carrier tape (a) Are formed so as to be thicker than a plating thickness (b) of a gold plating layer electrolytically deposited on an external terminal connecting portion to be joined to the conductive metal ball on the back surface of the film carrier tape.

With this configuration, the current control device for the front surface electrode and the current control device for the back surface electrode provide:
The current flowing between the surface and the surface electrode of the film carrier tape and the current flowing between the back surface and the back electrode of the film carrier tape are individually controlled to flow between the surface and the surface electrode of the film carrier tape. The current can be made larger than the current flowing between the back surface of the film carrier tape and the back surface electrode.

As a result, a gold plating layer having a sufficient thickness is formed in a portion required for bonding with the bump electrode formed on the electronic component, and a good bonding state is formed between the bump electrode and the electronic component side connection terminal. Can be formed. Also, on the surface of the wiring pattern inside the external connection terminal hole to which the solder ball is joined,
There can be a small amount of gold needed to join the solder balls, so that at the joint between the solder balls and the wiring pattern, the excess gold-solder alloy that causes the solder balls to fall off Is not formed.

Therefore, it is possible to provide a film carrier tape for mounting electronic parts, which is less likely to fall off the wiring pattern from the wiring pattern, has excellent durability, enables reliable electrical connection, and is inexpensive. Further, the method of manufacturing a film carrier tape for mounting electronic components of the present invention, in the plating bath, disposing a pair of shielding members for shielding the vicinity of both longitudinal edges of the film carrier tape, respectively, The current flowing between the front surface and the surface electrode of the film carrier tape and the current flowing between the back surface and the back surface electrode of the film carrier tape are subjected to electrolytic deposition in a state where they do not interfere with each other. .

Further, the apparatus for manufacturing a film carrier tape for mounting electronic components according to the present invention includes a pair of shielding members provided in the plating bath for shielding the vicinity of both longitudinal edges of the film carrier tape. The current flowing between the front surface and the surface electrode of the film carrier tape, and the current flowing between the back surface and the back surface electrode of the film carrier tape perform electrolytic deposition in a state where they do not interfere with each other. It is characterized by comprising.

With this configuration, the current flowing between the front surface and the front electrode of the film carrier tape and the current flowing between the back surface and the back electrode of the film carrier tape are shielded by the shielding member. As a result, mutual interference does not occur, that is, the mutual sneak of current can be prevented. Thereby, the current flowing between the front surface of the film carrier tape and the front electrode by the front electrode current control device and the back electrode current control device,
Individual control of the current flowing between the back surface of the film carrier tape and the back surface electrode can be reliably performed.

Accordingly, it is possible to accurately control the amount of gold plating on the surface of the connection terminal on the electronic component side and the amount of gold plating on the surface of the wiring pattern in the external connection terminal hole. Further, in the method for producing a film carrier tape for mounting electronic components of the present invention, the average plating thickness (a) of the gold plating layer on the surface of the electronic component side connection terminal is in the range of 0.5 to 1.5 μm, The current is controlled so that the average plating thickness (b) of the gold plating layer of the external terminal connection portion to be joined to the conductive metal ball is 0.5 μm or less.

In the apparatus for manufacturing a film carrier tape for mounting electronic components according to the present invention, the average plating thickness (a) of the gold plating layer on the surface of the connection terminal on the electronic component side is 0.5 to 0.5.
The average plating thickness of the gold plating layer of the external terminal connection part which is within the range of 1.5 μm and is connected to the conductive metal ball (b)
Is controlled to be 0.5 μm or less by the current control device for the front electrode and the current control device for the back electrode.

As a result, a gold plating layer having a sufficient thickness is formed at a portion necessary for bonding with the bump electrode formed on the electronic component, and a good bonding state is formed between the bump electrode and the electronic component side connection terminal. Can be formed. Also, on the surface of the wiring pattern inside the external connection terminal hole to which the solder ball is joined,
There can be a small amount of gold needed to join the solder balls, so that at the joint between the solder balls and the wiring pattern, the excess gold-solder alloy that causes the solder balls to fall off Is not formed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments (examples) of the present invention will be described with reference to the drawings. 1 and 2 show examples of cross sections in a state where electronic components are mounted on a film carrier tape for mounting electronic components manufactured by the present invention. FIG. 1 shows that the bump electrode of the electronic component is on the upper surface of the electronic component, the electronic component is attached on the wiring pattern, and the electronic component connection terminal and the bump electrode on the edge of the attached electronic component are attached. 1 shows an example of a film carrier tape (FBGA) for mounting electronic components of a type connected by conductor wires.

FIG. 2 shows a case where a slit is formed in a portion of the insulating film corresponding to the edge of the electronic component, a wiring pattern is formed so as to straddle the slit, and the electronic component is attached on the wiring pattern. An electronic component mounting film carrier tape (FBGA) that bonds while cutting the electrode formed on the lower edge of the electronic component and the wiring pattern (electronic component connection terminal) formed across the slit at the outer end. 3) shows an example.

As shown in FIG. 1, the film carrier tape 10 for mounting electronic components according to the present invention has a wiring pattern 14 formed on one surface of an insulating film 11 by etching a conductive metal foil. . The insulating film 11 is formed of a flexible insulating synthetic resin film. The insulating film 11 used here has flexibility, and is in contact with an acid or the like during etching, so that it is resistant to such chemicals, and is deteriorated by heating during bonding. It does not have heat resistance. Examples of a material for forming such an insulating film 11 include polyester, polyamide, liquid crystal polymer, and polyimide. In particular, in the present invention, it is preferable to use a film made of polyimide.

Examples of the polyimide film constituting the insulating film 11 include a wholly aromatic polyimide synthesized from pyromellitic dianhydride and an aromatic diamine, and a synthetic film formed from biphenyltetracarboxylic dianhydride and an aromatic diamine. Wholly aromatic polyimide having a biphenyl skeleton. Particularly, in the present invention, a wholly aromatic polyimide having a biphenyl skeleton (eg, trade name: Upilex S, manufactured by Ube Industries, Ltd.) is preferably used. The thickness of the insulating film 11 usable in this method is
Usually 7.5 to 125 μm, preferably 25 to 75 μm
Within the range.

The insulating film 11 used in the present invention includes:
Further, a number of external connection terminal holes 21 for embedding conductive metal balls (solder balls) 20 are formed. The external connection terminal hole 21 is formed in a portion of the insulating film 11 occupied by the electronic component 50 to be mounted.
A conductive metal ball 20 is disposed in the external connection terminal hole 21 so that the conductive metal ball 20 can be joined to the wiring pattern 14 formed so as to cover the surface of the external connection terminal hole 21.

The diameter of the conductive metal ball 20 is usually
It is 0.2 to 1.0 mm, preferably 0.2 to 0.5 mm.
The external connection terminal hole 21 is formed such that when the conductive metal ball 20 such as a solder ball is arranged, the adjacent conductive metal ball 20 does not come into contact with the conductive metal ball 20. The formation pitch of 21 varies depending on the size of the conductive metal ball to be used, but is usually 0.3 to 2.0 mm, preferably 0.3 to 1.0 mm.

As shown in FIG. 2, while cutting the electronic component side connection terminal 34 which is a wiring pattern formed so as to straddle the slit 31, the electronic component side connection terminal 3 is cut.
In a case where a method (beam lead bonding method) of bonding the electrode 4 to the electrode 51 formed on the bottom surface of the electronic component 50 is adopted, a slit 31 is further formed in the insulating film 11. The width of this slit is usually 0.4
２2.0 mm, preferably 0.6-1.5 mm.

Further, the insulating film 11 used in the present invention
On both edges in the longitudinal direction, a number of sprocket holes are provided at predetermined intervals. Further, through-holes for various purposes such as through-holes for positioning, defective package display, and package outer shape can be formed in the insulating film 11. The external connection terminal holes 21, slits 31, sprocket holes, and other through holes as described above can be formed by punching or the like.

The conductive metal foil 14 is laminated on one surface of the insulating film 11 in which various through holes or slits are formed as described above. In the present invention, as the conductor foil 14, a metal foil having conductivity and having a thickness of usually 3 to 35 μm, preferably 9 to 25 μm can be used. Specifically, examples of the conductive metal foil include a copper foil and an aluminum foil.

The conductor foil (metal foil) 1 having the thickness as described above
Instead of directly laminating the insulating film 11 on the insulating film 11, a very thin metal foil (for example, less than 6 μm)
The conductive metal layer can be formed by depositing a metal on the surface of the laminated ultrathin metal foil by, for example, a vapor deposition method or a plating method. Further, when a metal layer is formed by such a vapor deposition method or a plating method, a metal is directly deposited on the surface of the insulating film 11 to form a metal layer having a desired thickness (a metal plating layer, a metal vapor deposition layer, etc.).
May be formed.

The above-described conductive foil can be laminated on one surface of the insulating film 11 using an adhesive (not shown), or can be laminated without using an adhesive. Examples of the adhesive layer used herein include epoxy-based adhesives, curable adhesives such as polyimide-based adhesives and phenol-based adhesives, and these adhesives include urethane resins and melamine resins. , A polyvinyl acetal resin, a rubber component, or the like. When using an adhesive, the thickness of the adhesive is usually 8 to
It is 23 μm, preferably 10 to 21 μm. However, in the electronic component mounting film carrier tape of the present invention, the conductive metal foil 14 in the portion of the external connection terminal hole 21 formed in the insulating film 11 needs to be electrically connected to the conductive metal ball 20. Therefore, the adhesive layer is not formed on the back surface of the conductive metal foil 14 in this portion.

The conductive metal foil 1 thus laminated
4 is coated with a photoresist, the photoresist is exposed to a desired pattern and developed, and the remaining photoresist is used as a masking material to etch the conductive metal foil, thereby forming a conductive film on the insulating film 11. The wiring pattern 14 made of a conductive metal can be formed.
Note that the photoresist after the etching is removed by alkali washing or the like.

The wiring pattern 1 thus formed
The solder resist layer 24 can be formed on the surface of the substrate 4 except for the portion where the plating layer such as the electronic component side connection terminal 34 is formed. The solder resist coating liquid used when forming the solder resist layer 24 is a coating liquid having a relatively high viscosity in which a curable resin is dissolved or dispersed in an organic solvent. Examples of the curable resin contained in such a solder resist coating solution include an epoxy resin, an elastomer-modified epoxy resin, a urethane resin, an elastomer-modified urethane resin, a polyimide resin, and an elastomer-modified polyimide resin. And acrylic resin. In particular, it is preferable to use a modified elastomer. In such a solder resist coating solution, in addition to the resin components as described above, a curing accelerator, a filler, an additive, a thixo agent, a solvent, and the like, which are usually added to a solder resist coating solution, are added. be able to. Furthermore, in order to improve the characteristics such as flexibility of the solder resist layer 24, it is possible to mix fine particles having elasticity such as rubber fine particles.

Such a solder resist coating solution can be applied using a screen printing technique. The solder resist coating solution is applied except for a portion to be plated in the next step. The average coating thickness of such a solder resist is usually 1 to 80 μm, preferably 5 to 80 μm.
５０50 μm. After applying the solder resist coating liquid in this manner, the solvent is removed and the resin is cured to form the solder resist layer 24.
The resin forming the solder resist is usually cured by heating. The heat curing temperature for forming the solder resist layer is usually 80 to 180 ° C, preferably 120 to 1 ° C.
The temperature is 50 ° C., and the resin is normally cured by keeping the temperature within this range for 30 minutes to 3 hours.

In the electronic component mounting film carrier tape manufactured according to the present invention, the electronic component 50 is attached to the wiring pattern 14 for bonding. Is protected, and the wiring pattern 14 is also protected by the adhesive applied to attach the electronic component 50. Therefore, it is particularly necessary to form the solder resist layer as described above. is not.

After the solder resist layer 24 is applied in this manner, a gold plating layer 36 is formed on the exposed wiring pattern 14. For example, as shown in FIG. 1, the gold plating layer 36
When the conductive metal wire 33 is used to attach the bump electrode 51 formed on the upper surface of the electronic component (IC) 50 and the electronic component-side connection terminal 34, The wire bonding property between the wire 33 and the electronic component side connection terminal 34 is ensured. The conductive metal wire 3 in this case
As 3, a gold wire having an average cross-sectional diameter of usually 10 to 50 μm, preferably 18 to 38 μm is used.

When bonding the gold wire 33 to the electronic component side connection terminal 34, the electronic component side connection terminal 3
It is necessary that a gold plating layer 36 having a predetermined thickness is formed on the surface (front surface) to which the fourth gold wire 33 is bonded. However, as shown in FIG. 3, the conductive metal balls 20 are inserted into the external connection terminal holes 21 formed in the insulating film 11 from the surface (back surface) of the insulating film 11 where the wiring pattern 14 is not formed. Then, it is necessary to join with the wiring pattern 14 forming the bottom (closed end) of the external connection terminal hole 21. Conductive metal ball 2
When gold is present on the surface of the wiring pattern 14, the solder ball used as 0 and the wiring pattern 14 are bonded by forming a gold-solder alloy. This gold-solder alloy is
For example, when the percentage of gold in the solder exceeds 4%, the impact value sharply decreases, and the solder has a characteristic of being very hard and brittle.

For this reason, if this gold-solder alloy is excessively present on the joint surface between the solder ball 20 and the wiring pattern 14, that is, the bottom (closed end) of the external connection terminal hole 21
When the thickness of the gold plating layer 37 formed on the back surface of the wiring pattern 14 that forms the solder balls becomes large, the shear strength of the solder balls 20 decreases, and the solder balls 20 easily fall off.

This tendency is caused by the fact that the bump electrode 51 formed directly on the bottom edge of the electronic component (IC) 50 is cut while cutting the wiring pattern 14 formed so as to straddle the slit 31 as shown in FIG. This also occurs in the case of a film carrier tape for mounting electronic components of the beam lead bonding type which is welded to (usually made of gold). In the electronic component mounting film carrier tape 10 manufactured by the present invention, the plating layer 3 on the surface of the electronic component side connection terminal 34 that is directly welded to the gold wire 33 or the gold bump electrode.
6 is the same as the plating thickness (b) of the gold plating layer 37 of the external terminal connection portion 38 to be joined to the conductive metal ball.
It is formed thicker.

In the present invention, the gold plating thickness (a) of the plating layer 36 on the surface of the electronic component side connection terminal 34 is shown.
Is usually 0.5 to 1.5 μm, preferably 0.7 to
The thickness should be in the range of 1.3 μm. Further, the average plating thickness (b) of the gold plating layer 37 of the external terminal connection portion 38 to be joined to the conductive metal ball 20 is usually 0.3 μm or less, preferably in the range of 0.0005 to 0.2 μm. I do. In other words, the gold plating thickness of the gold plating layer 37 formed on the external terminal connection portion 38 is preferably as thin as possible, and may be as small as a layer cannot be formed.

By setting the gold plating thickness (a) on the surface of the electronic component side connection terminal 34 within the above range, when the gold wire 33 is wire-bonded to the bump electrode 51 of the electronic component, the gold wire 33 The welding strength between the component side connection terminal 34 and the bump electrode 51 becomes higher than the tensile strength of the gold wire. Therefore, the electronic component side connection terminal 34 and the bump electrode 51 having the gold plating thickness as described above are
After wire bonding using a gold wire 33 having a diameter of m, the wire bonding pull strength is measured. When a tensile stress of 8 g is applied to the gold wire, the electronic component side having the gold plating layer 36 having the above thickness is obtained. Connection terminal 34
No separation occurs at the fused portion of the gold wire 33 and the gold wire itself, and the gold wire itself is cut.

That is, when the gold plating layer 36 in the above range is formed on the surface of the electronic component side connection terminal 34, the welding strength between the surface and the gold wire 33 becomes higher than the tensile strength of the gold wire 33, This film carrier tape is
It has very good bondability. It is to be noted that the above excellent bondability is not impaired by increasing the thickness of the gold plating layer beyond the above range, but it is disadvantageous in terms of cost, and no remarkable increase in bondability is observed.

On the other hand, the average plating thickness of the gold plating layer 37 of the external terminal connection portion 38 to be joined to the conductive metal ball 20 (b)
By reducing the thickness, the formation of a gold-solder alloy can be suppressed, so that the solder balls 20 are directly bonded to the wiring patterns 14 constituting the external terminal connection portions 38. As a result, the shear strength of the solder balls is increased, and the solder balls (conductive metal balls) 20 serving as external terminals hardly fall off.

In the film carrier tape for mounting electronic components manufactured according to the present invention, the electronic component side connection terminals 34
Ratio of the average plating thickness (a) of the gold plating layer on the surface of (a) to the average plating thickness (b) of the gold plating layer of the external terminal connection portion 38 to be joined to the conductive metal ball (average plating thickness (b) / average plating thickness) (Ratio of (a)) is usually in the range of 0.001 to 0.6, preferably in the range of 0.001 to 0.3. As described above, the plating thickness (b) of the gold plating layer 37 of the external terminal connection portion 38 to be joined to the conductive metal ball 20
Is preferably thin, so that the average plating thickness (b)
The lower limit of the ratio of (/ a) the average plating thickness (a) is preferably as close to 0 as possible, and this value may be 0.

In practice, when gold plating is performed on the film carrier tape, as described later, a certain gap is formed from the film carrier tape in the plating solution, and the electrodes are arranged so that the electrodes and the film carrier tape are connected to each other. By applying a voltage during the current flow and flowing a current, an amount of gold corresponding to the flowed current is electrolytically deposited on the surface of the wiring pattern in contact with the gold plating solution. Therefore, as long as the external terminal connection portion 38 contacts the gold plating solution, a very small amount of gold is deposited on the external terminal connection portion 38, so that the ratio of the above average plating thickness (b) / average plating thickness (a) is obtained. It is difficult to set the lower limit to 0 by an industrial method for manufacturing a film carrier tape for mounting electronic components.

As described above, it is difficult to reduce the plating thickness of the gold plating layer of the external terminal connection portion 38 to which the solder balls 20 are bonded to 0 μm. The lower limit of the ratio of the average plating thickness (b) / average plating thickness (a) is usually 0.001 because there may be a slight advantage in characteristics such as rust prevention characteristics and mechanical strength. Is preferred.
On the other hand, the upper limit value means that the average plating thickness (b) becomes thicker or the average plating thickness (a) becomes thinner.
Considering the bonding strength of the above, it is preferably 0.6.

In the film carrier tape for mounting electronic components manufactured by the present invention, gold plating layers 36 and 37 having different average plating thicknesses are formed on the electronic component side connection terminals and the external terminal connection portions 38. A nickel plating layer may be formed between the gold plating layers 36 and 37 and the wiring pattern 14. The nickel plating layer is a relatively hard layer, so that, for example, when the gold wire 33 is wire-bonded to the gold plating layer 36 using an ultrasonic wave, at least a part of the ultrasonic wave is reflected by the nickel layer. Thus, wire bonding can be performed efficiently.

The nickel-plated layer serves as the electronic component-side connection terminal 3 when welding the gold wire 33 using ultrasonic waves.
4 is formed between the wiring pattern 14 formed of an electrolytic copper foil or the like and the gold plating layer 36. When forming a nickel layer in this way, the thickness of the nickel layer is usually 0.
It is from 0001 to 10 μm, preferably from 0.001 to 2 μm. On the other hand, a thin gold-plated layer 37 is formed in the external terminal connection part 38 for reasons such as a manufacturing process. In order to join the solder ball 20 to the gold-plated layer 37, it is usual to use ultrasonic waves. , The external terminal connection part 38
In particular, it is not necessary to form a nickel layer. However, the present invention does not exclude the formation of a nickel layer on this portion. In the above description, an example in which a nickel layer is used in order to improve the welding efficiency of a gold wire by ultrasonic waves has been described. In the present invention, instead of such a hard nickel layer, or together with the nickel layer, a hard layer is similarly used. Ni-P layer, Ni-B
And a hard layer such as a Sn—Ni layer.
These hard layers may be composite layers.

Hereinafter, in the film carrier tape 10 for mounting electronic parts manufactured by the present invention, the gold wire 3
3 or the gold plating thickness (a) of the plating layer 36 on the surface of the electronic component side connection terminal 34 directly welded to the gold bump electrode,
A method of forming the gold plating layer 37 of the external terminal connection portion 38 to be bonded to the conductive metal ball so as to be thicker than the plating thickness (b) will be described with reference to FIG.

As shown in FIG. 4, the apparatus 100 for manufacturing a film carrier tape for mounting electronic components according to the present invention includes a gold plating bath 102.
A gold plating solution 104, for example, a potassium gold cyanide solution (KAu (CN) ₂ ) is always supplied with a new gold plating solution 104 by a circulation device (not shown).

The gold plating bath 102 is a film carrier tape 1 for mounting an electronic component, which is provided with a portion of the wiring pattern 14 which is exposed by applying the solder resist layer 24 of the present invention.
0 is formed in a trough shape having a substantially rectangular cross-sectional shape and extending in the longitudinal direction so as to be conveyed while being immersed in the gold plating solution 104 in a state of standing inside. That is, FIG.
As shown in FIG. 4, the film carrier tape 10 for mounting electronic components is transported substantially in the center of the gold plating bath 102 in a direction perpendicular to the plane of FIG.

The gold plating bath 102 is separated from the surface 10a of the film carrier tape 10 for mounting electronic components, that is, the electronic component-side connection terminals 34 by a predetermined distance (La). ) Are arranged. Similarly, a back surface electrode 108 constituting an anode is disposed at a predetermined distance (Lb) away from the back surface 10 b of the electronic component mounting film carrier tape 10, that is, the external terminal connection portion 38. Have been. Note that these electrodes 10
Reference numerals 6 and 108 are separately connected to a power supply (not shown), and are disposed in the gold plating bath 102 so as to extend along the longitudinal direction of the gold plating bath 102. Further, these electrodes 106 and 108 are composed of inert electrodes such as Pt. In this case, the cathode (cathode)
Is a portion of the wiring pattern 14 of the film carrier tape 10 for mounting electronic components, and is separately connected to a power supply by wiring (not shown).

The distance La and the distance Lb are not particularly limited, but in consideration of the liquid resistance and the liquid stirring, the distance La is 10 to 100 mm, preferably 4 to 100 mm.
It is desirable that the distance Lb is 0 to 70 mm and the distance Lb is 10 to 100 mm, preferably 40 to 70 mm. The distance La and the distance Lb can be the same distance or different distances.

Further, in the gold plating bath 102, a pair of shielding members 110 and 112 for shielding the vicinity of both edges 10c and 10d in the longitudinal direction of the film carrier tape 10 for mounting electronic components are provided inside the gold plating bath 102. It is arranged to be fixed. These shielding members 110, 1
12 has a substantially U-shaped cross section, and its shielding portion 110
a, 112a shield a portion of the surface 10a of the film carrier tape 10 for mounting electronic components, and the shielding portion 1
10b and 112b shield a part of the back surface 10b of the film carrier tape 10 for mounting electronic components,
The shielding member body portions 110c and 112c are provided at both longitudinal edges 10 of the film carrier tape 10 for mounting electronic components.
c, 10d are configured to be shielded. Note that these shielding members 110 and 112 are disposed so as to extend along the longitudinal direction of the gold plating bath 102.

In this case, the distance la between the shielding portions 110a and 112a of the shielding members 110 and 112 and the surface 10a of the electronic component mounting film carrier tape 10, the shielding portions 110b and 112b of the shielding members 110 and 112, and the electronic component The distance lb from the back surface 10b of the mounting film carrier tape 10 is 0 to 0 in consideration of shielding.
10 mm, preferably 0.5-1 mm, the distance lb is
It is desirably 0 to 10 mm, preferably 0.5 to 1 mm. Note that these distances la and lb can be the same distance or different distances.

Further, the distance S at which the shielding portions 110a and 112a of the shielding members 110 and 112 shield (cover) the surface 10a of the film carrier tape 10 for mounting electronic components.
a, shielding parts 110b, 11 of shielding members 110, 112
The distance Sb at which the rear surface 2b shields (covers) the back surface 10b of the electronic component mounting film carrier tape 10 is determined by the distance Sb in consideration of preventing the tape from coming off and preventing the pattern portion from being scratched.
a is 1 to 6 mm, preferably 2 to 4 mm, and the distance Sb
Is desirably 1 to 6 mm, preferably 2 to 4 mm. That is, these shielding portions 110a, 112
The ratio at which a, 110b, and 112b shield the front surface 10a and the back surface 10b of the electronic component mounting film carrier tape 10, respectively, is 2 to 13% in the width direction of the electronic component mounting film carrier tape 10, preferably 4%. ~
It is desirable to set it in the range of 8%.

The distance Sa and the distance Sb are the same.
It can be one distance or different distances
is there. As such shielding members 110 and 112,
Flow, ie, the negative electron (e^-)
For example, synthetic resin such as vinyl chloride resin, ceramic
It is desirable to use insulating material such as
It can also be comprised from the insulating member of. In addition, these
The thickness of the shielding members 110 and 112 is negative electron (e ^-)of
Any thickness can be used as long as it is a thickness that impedes flow.
However, considering structural strength, it is 0.5 to 10 m
m, preferably 2 to 5 mm.

On the other hand, a front electrode 106 and a back electrode 108
Are connected to a front electrode rectifier 114 that is a front electrode current controller and a back electrode rectifier 116 that is a back electrode current controller, and are controlled by a control based on a program preset in the controller 120. A current Ia flowing between the surface 10a of the film carrier tape 10 for mounting electronic components and the surface electrode 106, respectively;
Back surface 10 of film carrier tape 10 for mounting electronic components
The current Ib flowing between b and the back electrode 108 can be individually controlled.

That is, as described above, the current flowing between the front surface 10a of the film carrier tape 10 for mounting electronic components and the front electrode 106 is applied to the back surface 10b of the film carrier tape 10 for mounting electronic components and the back electrode 108. The plating thickness (a) of the gold plating layer 34 electrolytically deposited on the surface of the electronic component-side connection terminal 34 of the electronic component mounting film carrier tape 10 is controlled so as to be larger than the current flowing therebetween, and the electronic component mounting is performed. It is set to be thicker than the plating thickness (b) of the gold plating layer 37 electrolytically deposited on the external terminal connection portion 38 that is joined to the conductive metal ball 20 on the back surface 10b of the film carrier tape 10 for use.

Specifically, as described above, the gold plating thickness of the plating layer 36 on the surface of the electronic component side connection terminal 34 (a)
Is usually 0.5 to 1.5 μm, preferably 0.7 to
The thickness of the conductive metal ball 20 is set within a range of 1.3 μm.
In order to make the average plating thickness (b) of the gold plating layer 37 of the external terminal connecting portion 38 to be joined to the surface terminal electrode usually 0.3 μm or less, preferably in the range of 0.0005 to 0.2 μm. Rectifier 114 allows the surface 10a of the electronic component mounting film carrier tape 10 and the surface electrode 1
06 is set to 3 to 10 A, preferably 5 to 8 A.
It is desirable that the current Ib flowing between the back surface 10b of the film carrier tape 10 and the back electrode 108 is 0 to 2A, preferably 0.1 to 1.5A. The current I
The ratio of a to the current Ib is desirably 5: 1 to 100: 1, preferably 10: 1 to 20: 1.

Further, the gold plating bath 102 is fed to the electronic component mounting film carrier tape 10 at a speed and time of 0.5 to 10 m / min, preferably 1 to 10 m / min.
It is desirable to set it to 5 m / min. The manufacturing apparatus 100 of the present invention configured as above operates as follows. At a substantially central portion of the gold plating bath 102, the electronic component mounting film carrier tape 10 is transported along the shielding members 110 and 112.

At this time, by controlling the rectifier 114 for the front electrode and the rectifier 116 for the back electrode based on the control based on a program preset in the control device 120, the front surface 10a of the film carrier tape 10 for mounting electronic parts is controlled. The current Ia flowing between the front surface electrode 106 and the back surface 10b of the electronic component mounting film carrier tape 10
Is controlled so as to be larger than the current Ib flowing between the first electrode and the back electrode 108.

As a result, the plating thickness (a) of the gold plating layer 34 electrolytically deposited on the surface of the electronic component side connection terminal 34 of the electronic component mounting film carrier tape 10 is reduced by the back surface 10 b of the electronic component mounting film carrier tape 10. The thickness is larger than the plating thickness (b) of the gold plating layer 37 electrolytically deposited on the external terminal connection portion 38 to be joined to the conductive metal ball 20, and the thickness falls within the above-mentioned predetermined thickness range.

At this time, the vicinity of both edges 10c, 10d in the longitudinal direction of the film carrier tape 10 for mounting electronic components is shielded by the shielding members 110, 112, that is, the shielding parts 110a, 112a, 110b, 11
2b and the shielding member main bodies 110c and 112c. Accordingly, as shown by the dotted lines in FIG. 4, the respective currents from the front electrode 106 and the back electrode 108, that is, the negative electrons (e ⁻ ) do not interfere with each other, and the electronic component mounting film carrier tape 10 Are prevented from wrapping around the opposite back surface 10b and front surface 10a.

Thus, the current Ia flowing between the front surface 10a of the film carrier tape 10 for mounting electronic components and the front electrode 106 and the current Ia flowing between the back surface 10b and the back surface electrode 108 of the film carrier tape 10 for mounting electronic components. Individual control with the current Ib can be reliably performed. Therefore, the amount of gold plating on the electronic component side connection terminal surface 34 and the amount of gold plating on the surface of the wiring pattern 14 in the external connection terminal hole 21 can be accurately controlled.

As a result, a gold plating layer 36 having a sufficient thickness is formed in a portion necessary for bonding with the bump electrode 51 formed on the electronic component 50, and the gold plating layer 36 is formed between the bump electrode 51 and the electronic component side connection terminal 34. Can form a good bonding state. Further, the surface of the wiring pattern 14 in the external connection terminal hole 21 to which the solder ball 20 is joined is
There is a small amount of gold required for the bonding of the solder balls 20 (37), so that the bonding between the solder balls 20 and the wiring pattern 14 causes excess solder balls 20 to fall off. No gold-solder alloy is formed.

Accordingly, it is possible to provide the film carrier tape 10 for mounting electronic parts, in which the solder balls 20 do not easily fall off the wiring pattern 14, are excellent in durability, can be reliably connected electrically, and are inexpensive. The film carrier tape 10 for mounting an electronic component having the above-described configuration manufactured by the present invention is firstly an insulating film 1.
1 is filled with a small amount of flux into the external connection terminal holes 21 opened on the back surface thereof.
The solder balls 2 each being a conductive metal ball
0, the solder ball 20 is heated to a temperature equal to or higher than the melting temperature of the solder ball 20 (usually 180 to 280 ° C.), and then cooled to place the solder ball 20 in the external connection terminal hole 21.
Embed in a state where it is joined to

The conductive metal ball 20 used here is usually a solder ball, which is an alloy of lead and tin. However, a conductive metal ball equivalent to this may be used. is there. Thus, the external connection terminal hole 21
After a conductive metal ball 20 made of a metal having conductivity and melting at a low temperature such as a solder ball is disposed on the surface, the surface opposite to the surface on which the solder ball 20 is disposed, that is, the wiring pattern 14 is formed. Preferably, an adhesive 55 having elasticity is applied on the solder resist on the surface on which the electronic component 50 is to be fixed.

Then, as shown in FIG.
In the case of the electronic component 50 in which the bump electrode 51 is formed on the surface opposite to the bonding surface of the electronic component 50, the electronic component 50 extending outward from the edge portion of the electronic component 50 temporarily fixed to the surface of the insulating film 11. The component side connection terminal 34 and the bump electrode 51 are wire-bonded using a conductive metal wire 33 such as a gold wire. When performing this wire bonding using ultrasonic waves, the ultrasonic output at this time is usually 0.1 to
3.0 W, preferably 0.3 to 2.5 W, the application time is usually 1 to 50 msec, preferably 5 to 40 msec, and the load is usually 10 to 200 g, preferably 40 to 1 g.
50 g. The stage temperature at this time is usually 70
It is set within the range of ~ 250 ° C.

When using a beam lead bonding type film carrier tape 10 for mounting an electronic component as shown in FIG. 2, a jig is brought into contact with the lower portion of the slit 31 to apply a load of about 5 to 100 g. Slit 31
Over the wiring pattern 14 formed so as to straddle. A notch is formed in the vicinity of the outer edge of the slit 31 of the wiring pattern 14 in advance. A stress of about 100 to 100 g, preferably about 20 to 80 g is applied to push up. As a result, the wiring pattern is cut at the notch, and the bump electrode 51 made of gold and the cut wiring pattern 14 are usually 30 to 200 mW, preferably 40 to 1 mW.
By applying an ultrasonic wave of 50 mW for a period of usually 20 to 1000 msec, preferably 40 to 600 msec, the electronic component can be favorably mounted on the film carrier tape 10. The stage temperature during this mounting is usually 80
~ 250 ° C.

After performing bonding in this manner,
This bonding portion is sealed with a curable resin such as an epoxy resin. Further, if necessary, the electronic component and the entire bonding portion can be sealed with a curable resin.
The preferred embodiments of the present invention have been described above.
The present invention is not limited to this. In the above embodiment, for example, the shielding members 110 and 112 are
2 is fixed so as to be fixed inside, but it is also possible to convey the inside of the gold plating bath 102 together with the film carrier tape 10 for mounting electronic components, without departing from the object of the present invention. Various changes are possible within the scope.

[0073]

EXAMPLES Next, the present invention will be described in more detail with reference to examples of the present invention, but the present invention should not be construed as being limited thereto.

[0074]

Example 1 In Example 1, a TFBGA (Tape Finepitch Ball Grid Array), which is a film carrier tape for mounting electronic components of a wire bonding type, was manufactured. As shown in FIG. 1, a polyimide film (trade name: Upilex S, manufactured by Ube Industries, Ltd.) having a thickness of 75 μm, a width of 35 mm, and a length of 100 m coated with an epoxy adhesive having a thickness of 12 μm on one surface is formed. At the same time as forming sprocket holes on both edges of the insulating film at predetermined intervals,
The external connection terminal hole 21 was formed by punching. The diameter of the external connection terminal hole 21 is 0.4 mm, and the distance between the adjacent external connection terminal holes 21 is 0.
It was 8 mm.

Next, an electrolytic copper foil having a thickness of 18 μm was laminated on the polyimide film in which the through holes were formed. A copper wiring pattern 14 was formed on one surface of the insulating film 11 by applying a photoresist to the copper foil surface, exposing, developing and etching. An epoxy solder resist was applied to the surface of the wiring pattern 14 thus formed, except for the electronic component side connection terminals 34 formed at the edges and the electrodes for passing current to the connection terminals.

The film carrier tape was subjected to 2 μm electro nickel plating in a nickel sulfamate bath. The film carrier tape was electroplated in a cyan gold bath using the manufacturing apparatus 100 as shown in FIG. At this time, the shielding member 110 made of vinyl chloride resin,
Using 112, plating was performed under the following conditions.

Shielding members 110 and 112: made of vinyl chloride resin Distance La, LB: La = 50 mm, LB = 50 mm Distance la, lb: la = 1 mm, lb = 1 mm Distance Sa, Sb: Sa = 2 mm, Sb = 2 mm Film Carrier tape transport speed: 3 m / min Currents Ia, Ib: Ia = 0.6 A, Ib = 7 A By gold plating as described above, the average thickness of the surface of the electronic component side connection terminal 34 on the wire-bonded terminal is increased. A gold plating layer 36 having a thickness of 1 μm was formed.

On the other hand, the thickness of the gold-plated layer 37 at the external terminal joint 38 composed of the wiring pattern 14 covering the upper surface of the through hole 21 formed in the insulating film 11 is 0.1 μm.
m, and the ratio of the average plating thickness (b) of the gold plating layer of the external terminal connection portion 38 to be joined to the conductive metal ball / the average plating thickness (a) of the gold plating layer on the surface of the electronic component side connection terminal is 0. It was one.

A solder ball having a diameter of 300 μm is arranged in an external connection terminal hole opened on the back surface of the insulating film.
C. and was fused to the external terminal connection portion 38 (the wiring pattern at the bottom of the external connection terminal hole). The solder strength of this solder ball was determined by (device name: PC-240 DAGE).
The average value of the shear strength of the solder balls was 400 g, and when 100 terminals were observed for each of 10 samples, no dropping of the solder balls was observed.

An adhesive 55 is applied to the surface of the solder resist 24 of the film carrier to which the solder balls are fused as described above, and an electronic component (IC) 50 is attached. The bump electrode 51 formed in the portion and the electronic component side connection terminal 34 were electrically connected by wire bonding using a gold wire 33 (diameter: 25 μm, purity 99.99%).

The conditions for wire bonding are as follows. Ultrasonic power: 1.26 W Application time: 22 ms Load: 90 g Stage temperature: 150 ° C. Apparatus used: Kulicke & Softa, 4
524 ball bonder
g, 2 g, 4 g, and 8 g, the cut state was observed by applying a load of 8 g. The gold wire was cut by applying a load of 8 g (breakage in mode 1). Peeling of bonded gold wire (mode 2 break)
Was not seen.

[0082]

Comparative Example 1 In Example 1, when plating with gold, the surface 10a of the film carrier tape 10 for mounting electronic components was used.
The current Ia flowing between the back surface electrode 106 and the current Ia flowing between the back surface 10b of the film carrier tape 10 for mounting electronic components and the back surface electrode 108 are set to the same current (current value 7A), and gold plating is performed. went.

As a result, 1 μm was applied to the surface of the electronic component side connection terminal.
The gold plating layer of m was formed, and the gold plating layer of 1 μm was also formed on the surface of the external terminal connection part 38. Solder balls were fused to the film carrier thus formed in the same manner as in Example 1. The shear strength of the solder ball fused in this way is 50 g,
The film carrier obtained in Example 1 showed only 1/8 of the shear strength of the solder ball.

[0084]

Example 2 In Example 1, a wire bonding type TFBGA was manufactured to measure the bondability and the shear strength of a solder ball.
As shown in the figure, beam lead bonding type FB
GA was manufactured. That is, as shown in FIG. 2, a wiring pattern was formed in the same manner as in Example 1 except that a slit 31 was previously formed in the polyimide film, and an electrolytic copper foil having an average thickness of 18 μm was laminated so as to cover the slit. Similarly, a gold plating layer was formed. The thickness of the gold plating layer formed on the surface of the electronic component side connection terminal connected to the bump electrode is 1 μm, and is formed on the surface of the external terminal connection portion 38 (the wiring pattern at the bottom of the external connection terminal hole). The thickness of the gold plating layer 37 was 0.1 μm.

After a solder ball having a diameter of 300 μm was fused to the thus obtained film carrier in the same manner as in Example 1, the shear strength of the solder ball was measured. When 100 terminals were observed, no solder balls were dropped off. Solder resist 2 of film carrier to which solder balls are fused as described above
An electronic component (IC) is adhered by applying an adhesive 55 to the surface of the electronic component (4), and between the bump electrode 51 formed on the lower edge of the electronic component (IC) and the electronic component side connection terminal 34. Thus, an electrical connection was formed by a beam lead bonding method while cutting the electronic component side connection terminal 34.

The beam lead bonding conditions are as follows. Ultrasonic output: 80 mW Application time: 600 ms Load: 60 g Stage temperature: 150 ° C. Apparatus used: Kulicke & Softa, 4
522 multi-process ball bonder After performing lead beam bonding in this way and applying a load of 1 g, 2 g, 5 g, 10 g, and 20 g to the lead and observing the cut state, the lead was subjected to a load of 20 g. The lead is cut at the lead (break of mode 1), and the lead connected to the bump electrode is peeled off (mode 2).
Was not observed).

[0087]

Comparative Example 2 In Example 2, the current Ia flowing between the front surface 10a of the film carrier tape 10 for mounting electronic components and the front electrode 106, the back surface 10b of the film carrier tape 10 for mounting electronic components, and the back electrode 108 And the current Ib flowing between them is the same current (current value 7A),
Gold plating was performed.

As a result, 1 μm is applied to the surface of the electronic component side connection terminal
The gold plating layer of m was formed, and the gold plating layer of 1 μm was also formed on the surface of the external terminal connection part 38. Solder balls were fused to the film carrier thus formed in the same manner as in Example 1. The shear strength of the solder ball fused in this way is 50 g,
The film carrier obtained in Example 2 showed only 1/8 of the shear strength of the solder ball.

[0089]

According to the present invention, the current flowing between the front surface and the front electrode of the film carrier tape and the rear surface and the back electrode of the film carrier tape are controlled by the current control device for the front electrode and the current control device for the back electrode. And the current flowing between the front and back electrodes of the film carrier tape can be made larger than the current flowing between the back and back electrodes of the film carrier tape. .

As a result, a gold plating layer having a sufficient thickness is formed at a portion necessary for bonding with the bump electrode formed on the electronic component, and a good bonding state is provided between the bump electrode and the electronic component side connection terminal. Can be formed. Also, on the surface of the wiring pattern inside the external connection terminal hole to which the solder ball is joined,
There can be a small amount of gold needed to join the solder balls, so that at the joint between the solder balls and the wiring pattern, the excess gold-solder alloy that causes the solder balls to fall off Is not formed.

According to the present invention, the current flowing between the front surface and the front electrode of the film carrier tape and the current flowing between the rear surface and the back electrode of the film carrier tape are shielded by the shielding member. As a result, mutual interference does not occur, that is, the mutual sneak of current can be prevented. Thereby, the current flowing between the front surface and the front electrode of the film carrier tape and the current flowing between the back surface and the back electrode of the film carrier tape are controlled by the current control device for the front electrode and the current control device for the back electrode. Individual control can be performed reliably. This makes it possible to accurately control the amount of gold plating on the surface of the electronic component side connection terminal and the amount of gold plating on the surface of the wiring pattern in the external connection terminal hole.

Accordingly, it is possible to provide a film carrier tape for mounting electronic components, which is less likely to fall off the wiring pattern from the wiring pattern, has excellent durability, enables reliable electrical connection, and is inexpensive. Further, the film carrier tape for mounting electronic components manufactured according to the present invention has a sufficient thickness on the wire bonding surface of the electronic component side connection terminal to be wire-bonded to the conductive metal wire (gold wire) used for wire bonding. Since the gold plating layer is formed, the conductor metal wire (gold wire) and the electronic component side connection terminal can be very strongly welded. In addition, only a very small amount of gold is present at the joint between the conductive metal ball represented by the solder ball and the wiring pattern, and the gold-solder alloy, which is the main cause of the fall of the solder ball, is used. It is not excessively supplied to the boundary between the solder ball and the wiring pattern. Therefore, by using the film carrier tape of the present invention, the electronic component can be more securely bonded, and the solder balls serving as the external terminals hardly fall off.

Further, not only the wire bonding type but also the beam lead bonding type film carrier as shown in FIG. 2, the very high beam lead bonding pull between the bump electrode and the electronic component side connection terminal. In addition to showing strength, the solder balls serving as external terminals are hardly detached. Also,
Since the thickness of the gold plating in the portion that does not require gold plating is made as thin as possible, the characteristics of the film carrier are improved, and the manufacturing cost of the film carrier having such excellent characteristics can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a cross section in a state where electronic components are mounted on a film carrier tape for mounting electronic components of the present invention by wire bonding.

FIG. 2 is a cross-sectional view showing an example of a cross section in a state where electronic components are mounted on a film carrier tape for mounting electronic components of the present invention by beam lead bonding.

FIG. 3 is a partially enlarged cross-sectional view schematically showing a joint portion between a solder ball and a wiring pattern in an enlarged manner.

FIG. 4 is a schematic view of an apparatus for manufacturing a film carrier tape for mounting electronic components according to the present invention.

[Explanation of symbols]

 10 Film carrier tape for mounting electronic components 11 Insulating film 14 Wiring pattern 20 Conductive metal balls 21 External connection terminal holes 24 Solder Resist 31 Slit 34 Electronic component side connection terminal 36 Gold plated layer of electronic component side connection terminal 37 Gold plated layer of external terminal connection part 38 External terminal connection Part 50: electronic component 51: bump electrode 55: adhesive 102: gold plating bath 106: front electrode 108: back electrode 110, 112 Shielding member 114 Rectifier for front electrode 116 Rectifier for back electrode 120 Control device

Claims (6)

[Claims] An electronic component-side connection terminal having an insulating film and a wiring pattern formed on one surface of the insulating film, wherein one end of the wiring pattern can be connected to an electronic component to be mounted. At the other end of the wiring pattern, an external terminal joint formed on a through hole formed in the insulating film is formed, and an insulating film surface on which the wiring pattern is formed. From the opposite side, by arranging conductive metal balls in the through holes, the conductive metal balls are electrically connected to the wiring pattern formed on the surface of the insulating film on the back surface of the insulating film via the conductive metal balls. A method for manufacturing an electronic component mounting film carrier tape configured to be electrically connectable to an electronic component connected to the A film carrier tape having a wiring pattern formed on one surface of the film is immersed in a gold plating bath, and a predetermined distance is set so as to face the surface of the film carrier tape, and a surface electrode is arranged in the gold plating bath. Along with a predetermined distance so as to face the back surface of the film carrier tape, a back surface electrode is disposed in a gold plating bath, and a current flowing between the front surface and the front surface electrode of the film carrier tape; The current flowing between the back surface and the back electrode of the tape is individually controlled, and the current flowing between the front surface and the front electrode of the film carrier tape flows between the back surface and the back electrode of the film carrier tape. A gold plating layer electrolytically deposited on the surface of the electronic component side connection terminal of the film carrier tape so as to be larger than the current. Wherein the plating thickness (a) is larger than the plating thickness (b) of the gold plating layer electrolytically deposited on the external terminal connection portion to be joined to the conductive metal ball on the back surface of the film carrier tape. Of manufacturing a film carrier tape for mounting electronic components. 2. A pair of shielding members for shielding the vicinity of both longitudinal edges of the film carrier tape in the plating bath, respectively, between a surface of the film carrier tape and a surface electrode. The film carrier for electronic component mounting according to claim 1, wherein the flowing current and the current flowing between the back surface and the back surface electrode of the film carrier tape perform electrolytic deposition in a state where they do not interfere with each other. Tape manufacturing method. 3. An average plating thickness (a) of a gold plating layer on a surface of the electronic component side connection terminal is in a range of 0.5 to 1.5 μm, and an external terminal connection portion to be joined to a conductive metal ball is provided. 3. The method according to claim 1, wherein the current is controlled so that the average plating thickness (b) of the gold plating layer is 0.5 μm or less. 4. An electronic component-side connection terminal having an insulating film and a wiring pattern formed on one surface of the insulating film, wherein one end of the wiring pattern has an electronic component-side connection terminal connectable to an electronic component to be mounted. At the other end of the wiring pattern, an external terminal joint formed on a through hole formed in the insulating film is formed, and an insulating film surface on which the wiring pattern is formed. From the opposite side, by arranging conductive metal balls in the through holes, an electrical connection is made to the wiring pattern formed on the surface of the insulating film on the back surface of the insulating film via the conductive metal balls. A manufacturing apparatus for manufacturing an electronic component mounting film carrier tape configured to be capable of being electrically connected to an electronic component connected to the insulated film. A gold plating bath in which a film carrier tape having a wiring pattern formed on one surface of the film is immersed; and a surface electrode disposed in the gold plating bath at a predetermined distance so as to face the surface of the film carrier tape. A predetermined distance so as to face the back surface of the film carrier tape, a back surface electrode disposed in a gold plating bath, a current flowing between the front surface and the front surface electrode of the film carrier tape, and the film A current control device for the front electrode and a current control device for the back electrode for individually controlling a current flowing between the back surface and the back electrode of the carrier tape, wherein the current control device for the front electrode and the current control device for the back electrode are provided. The current flowing between the front surface and the front electrode of the film carrier tape is applied between the rear surface and the back electrode of the film carrier tape. The plating current is set to be larger than the flowing current, and the plating thickness (a) of the gold plating layer electrolytically deposited on the surface of the electronic component side connection terminal of the film carrier tape is connected to the conductive metal ball on the back surface of the film carrier tape. An apparatus for manufacturing a film carrier tape for mounting electronic components, wherein the apparatus is configured to be formed to be thicker than a plating thickness (b) of a gold plating layer electrolytically deposited on a terminal connection portion. 5. A pair of shielding members disposed in the plating bath for shielding the vicinity of both longitudinal edges of the film carrier tape, respectively, between a surface of the film carrier tape and a surface electrode. 5. The electronic component according to claim 4, wherein a current flowing and a current flowing between the back surface of the film carrier tape and the back surface electrode perform electrolytic deposition in a state where they do not interfere with each other. Manufacturing equipment for mounting film carrier tapes. 6. An external terminal connection portion to be joined to a conductive metal ball, wherein the average plating thickness (a) of the gold plating layer on the surface of the electronic component side connection terminal is in the range of 0.5 to 1.5 μm. The current is controlled by the current control device for the front electrode and the current control device for the back electrode so that the average plating thickness (b) of the gold plating layer is 0.5 μm or less. An apparatus for manufacturing a film carrier tape for mounting electronic components according to claim 4.