JP3220693B2 - Method of manufacturing film carrier tape for mounting electronic components with reduced warpage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a film carrier tape for mounting electronic components with less warpage. More specifically, the present invention relates to a film carrier tape (TAB (Tape Automated Bonding) tape, T-BGA) for mounting an electronic component such as an IC or an LSI.
(Tape Ball Grid Array) tape, ASIC (Applicatio
n Specific Integrated Circuit) tape, CSP (Chip)
Size Package) tape and the like, and particularly relates to a method for producing a film carrier tape for mounting electronic components with less warpage.

[0002]

2. Description of the Related Art With the development of the electronics industry, IC
Demand for printed wiring boards on which electronic components such as (integrated circuits) and LSIs (large-scale integrated circuits) are mounted has been rapidly increasing. However, there has been a demand for smaller, lighter, and more sophisticated electronic devices. Recently, as a mounting method of electronic parts, TAB
A mounting method using a film carrier tape for mounting electronic components such as a tape, a T-BGA tape, a CSP and an ASIC tape has been adopted. In particular, liquid crystal display elements (LCDs), such as personal computers, which are required to have higher definition, thinner, and smaller frame areas of liquid crystal screens
Is increasingly important in the electronics industry that uses it.

Conventionally, such a film carrier tape for mounting electronic parts has been manufactured through the following steps as a method of manufacturing a TAB tape, for example. That is, first, after a flexible insulating film serving as a base material such as a polyimide film is punched with a press machine to form a predetermined through hole, a copper foil is attached to the flexible insulating film via an adhesive. A conductive metal foil such as that described above is attached by thermocompression bonding. Then, a photoresist is applied to the entire upper surface of the conductive metal foil, and the photoresist is exposed to ultraviolet light in a desired pattern shape using a photoresist mask. To dissolve away. The copper foil portion not covered with the photoresist is removed by chemically dissolving (etching) with an acid as an etchant, and then the photoresist is dissolved and removed with an alkaline solution to thereby remove the flexible insulating film. A desired wiring pattern is formed by a conductive metal foil such as a copper foil remaining on the top.

[0004] Among the wiring patterns, inner leads connected to devices (electronic parts) such as ICs and LSIs for preventing short circuits due to dust, whiskers, and migration during mounting, and for protecting and insulating between wirings. Except for the lead parts such as the outer leads connected to the liquid crystal display element, etc., apply a solder resist such as epoxy resin which is an insulating resin using a screen with a coating pattern, then dry and cure. To form a solder resist coating layer.

After the solder resist is hardened in this way, the lead portion is exposed to prevent oxidation and discoloration of the exposed lead portion and to secure the bonding strength with a connection portion such as a bump of a device connected to the lead portion. To
For example, it is manufactured by applying tin plating, gold plating, tin-lead eutectic alloy plating, or the like. Then, the inner lead of the TAB tape manufactured as described above and the electrode on the electronic component such as the IC chip are connected to each other by a method such as gang bonding (In) through a bump such as gold.
By connecting with ner Lead Bonding, electronic components can be mounted.

A film carrier tape to which electronic components such as an IC chip are connected is sealed with an epoxy resin or the like by potting or transfer molding to protect the electronic components such as the IC chip, and then the resin is cured by heating. Is done. On the other hand, the outer lead of TAB tape is
Thermo-compression bonding or connection to a printed circuit board such as a liquid crystal display element by anisotropic conductive film, soldering, etc. (Outer Lea
d Bonding).

[0007] The above description focuses on the TAB tape, but also when the T-BGA tape is used,
TAB from inner lead bonding to resin sealing
Although it is common to the tape, the solder balls are arranged in a matrix instead of the outer lead bonding, and the connection to the printed circuit board is made via these solder balls. For such a solder ball connection,
The solder resist layer has a transfer diameter of 100 to 800 μm two-dimensionally arranged vertically and horizontally at a pitch of 0.5 to 2.0 mm.
m are formed. Such TB
In connection with the solder ball connection of the GA tape, the wiring pitch is coarser than that of the outer lead bonding, and moreover, since it is possible to cope with an IC having a larger number of pins, the use thereof is increasing in recent years.

[0008] A CSP (Chip Size Package), in which the size of the IC and the size of the package of the film carrier tape are almost the same, and the connection method is mainly the same as that of the BGA, has recently become a BGA tape. Has been attracting attention as well. Such a T-BGA tape and CSP can be manufactured by substantially the same process and material as the conventional TAB tape. TAB tape,
Both the T-BGA tape and the CSP generally have a tape width of 35 mm to 70 mm, and the insulating film serving as a flexible substrate has a resin film of 20 μm to 125 μm.
For the copper foil for forming the wiring pattern, an electrolytic copper foil having a thickness of 12 to 35 μm is often used.

As described above, there are various types of electronic component mounting film carrier tapes used for mounting electronic components on electronic equipment. The cross-sectional structure of such electronic component mounting film carrier tapes is as follows. Each of them generally has a four-layer structure of a flexible insulating film, an adhesive, a conductive metal and a solder resist. Since the film carrier tape for mounting electronic components having the above-described configuration has completely different characteristics of the material constituting each layer, the resulting film carrier tape for mounting electronic components has warpage deformation in which the solder resist-coated surface is concave. Occurs.
It is considered that such a warp deformation is caused by a combined action of water absorption expansion of the flexible insulating film, curing contraction of the adhesive layer, thermal expansion and contraction of the conductive metal, curing contraction of the solder resist, and the like. ing. Then, in the width direction of the film carrier tape for mounting electronic components, it is easy to bend and deform so that the side on which the wiring pattern is formed becomes concave. The warp deformation in the tape width direction such that the surface on which the wiring pattern is formed becomes concave may be as large as about 20% of the tape width.

In recent years, wiring patterns formed on electronic parts have become very fine pitch. In the case of inner leads having the narrowest wiring pattern width, those having very fine pitch lead widths of not more than tens of μm or less. Are also manufactured. In such a fine pitch electronic component mounting film carrier tape, if the warp deformation is as large as 20% with respect to the tape width, the position of the bump electrode formed on the mounted electronic component and the electronic component mounting film are determined. The position of the inner lead of the carrier tape does not match, and normal bonding cannot be performed in many cases. In addition, as the fine pitch progresses as described above, the thickness of a member that has a function of holding the form of the electronic component mounting film carrier tape such as a flexible insulating film and a conductive metal foil to be used is reduced. As the pitch becomes finer from this aspect, warpage deformation is likely to occur, and the situation is increasing.

Under these circumstances, various methods have been proposed to reduce the warpage of the film carrier tape for mounting electronic components. For example, in claim 2 of JP-A-6-283576, in the production of a flexible circuit board having a pattern formed on a resin-based film,
After printing the thermosetting solder resist applied for the purpose of circuit protection, winding with the solder resist application side outside,
There is disclosed an invention of a method for manufacturing a flexible circuit board which can be mounted without warpage by heating and curing in a coil state. After applying the thermosetting solder resist using printing technology, the solder resist is coated on the outside and wound around a reel and cured by heating to prevent warpage that occurs in the length direction of the tape. Is extremely effective, but there is a problem that it is not as effective as the warpage prevention in the length direction with respect to the warpage deformation occurring in the width direction of the tape.

Further, the present applicant heats a film carrier tape for a semiconductor IC while imparting a reverse warp in the width direction, or restrains the tape while applying a reverse warp in the width direction while heating, and cools the tape. Later, an application was made for an invention of a method of releasing the reverse warpage to reduce the warpage in the width direction of the film carrier tape.
The application has been published in Japanese Patent Publication No. 11-111781. Further, as an improvement of the invention described in Japanese Patent Application Laid-Open No. H11-111781, a conductor wiring pattern is formed on the surface of a flexible insulating film, and a device or the like of the wiring pattern is contacted. By contacting the film carrier tape with the solder resist applied to the parts other than the terminal parts to a heating roll (specifically, a barrel-shaped heating roll) capable of imparting reverse warpage, and then quenching An application has been filed for the invention of a method for manufacturing a film carrier tape for mounting electronic components, which reduces the warpage of the tape (see Japanese Patent Application No. 11-142302).

By using the barrel-shaped heating roll as described above, the film carrier tape can be heated while giving a reverse warp, so that the warpage deformation can be effectively prevented. In particular, after giving a reverse warp by a barrel-shaped heating roll, by quenching, the reverse warp imparted in the subsequent steps, for example, becomes a stress that can resist warpage deformation generated by curing shrinkage of the solder resist,
The warpage is canceled by the reverse warpage, and good results are obtained for the warpage.

However, in order to contact such a barrel-shaped heating roll so that the tape is warped, it is necessary to considerably increase the contact pressure between the tape and the barrel-shaped heating roll. By physical contact between the barrel-shaped heating roll and the film carrier tape in
There is a possibility that a new problem may occur in that the fine pitched leads are likely to be deformed and cracks are easily generated in the cured solder resist.

On the other hand, Japanese Patent Application Laid-Open No. 8-45984 discloses a large number of conductor patterns each comprising a long flexible film substrate and pin-shaped connection terminals and mounting terminals arranged on the surface of the substrate. In a semiconductor device comprising a and a solder resist ink is applied at a predetermined position on the conductor pattern,
After applying heat for a certain period of time to the semiconductor device in a state where the conductor pattern forming surface is curled and raised in a direction perpendicular to the longitudinal direction and drying and curing the solder resist ink, plating is applied to the semiconductor device invention. It has been disclosed. Further, in this publication, in a semiconductor device in which a solder resist ink is applied to a predetermined position on a conductive pattern forming surface and plated, the conductive pattern forming surface is curled and raised in a direction perpendicular to a longitudinal direction. An invention of a semiconductor device, characterized in that the semiconductor device in a heated state is heated for a certain period of time, is disclosed.

After the solder resist ink is applied as described above, the solder resist ink is cured in a stretched state by being curled while the solder resist ink application surface is raised and heated for a certain period of time. And the reverse warpage caused by curling and heating are canceled out, so that a very good semiconductor device with almost no warp deformation can be obtained. Further, according to the method described in this publication, even after the warpage has once occurred, the above-described operation is very excellent in that the warpage that has occurred in the width direction of the tape can be eliminated. It is a method.

The warpage of the film carrier tape for mounting electronic components is not caused only by the curing shrinkage of the solder resist, but is caused by the water absorption expansion of the flexible insulating film and the curing shrinkage of the adhesive layer as described above. It is considered that the thermal expansion and shrinkage of the conductive metal and the hardening and shrinkage of the solder resist are caused by a combined action.

Therefore, if a stress that can resist curing shrinkage of the solder resist is applied to the film carrier tape for mounting electronic components before the solder resist is applied, the solder resist can be applied and cured by heating. Even when contracted, the tape does not warp.
The present inventor has found that in order to prevent such warpage deformation, it is effective to incorporate stress capable of resisting the warpage deformation into the film carrier tape for mounting electronic components, and to complete the present invention. Reached.

[0019]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a film carrier tape for mounting electronic components, which is less likely to be warped.

[0020]

SUMMARY OF THE INVENTION The method of the present invention for producing a film carrier tape for mounting electronic components with reduced warpage is provided by a method for forming a photo-conductive layer on a surface of a conductive metal foil adhered on a flexible insulating film via an adhesive layer. resist by coating photosensitive to form a desired pattern of photoresist, after the conductive metal foil a pattern of the photoresist as a masking material to form a wiring pattern consisting of by etching the conductive metal, a solder resist before applying the flexible insulating film is formed (a) wiring pattern
Step surface wiring pattern has been formed Ru adversely warped flexible insulating film wiring pattern is formed by shaping curved in the width direction in a convex shape so that the upward under heating, and And / or (B) a flexible insulating film on which the wiring pattern is formed
To under heating, allowed to respect the feeding direction of the flexible insulation film wiring pattern is formed, the wiring pattern between the plurality of leveler rollers arranged displaced alternately up and down is formed through the process, which Ru passed through a FLEXIBLE insulating film
By this, 30% or more of the surface of the flexible insulating film
Flexible with a wiring pattern made of conductive metal foil
Stress that resists warp deformation
It was, then, is characterized in that is applied to cure the solder resist leaving a joint terminal portion on the surface of the wiring pattern.

The method of the present invention comprises the steps of:
It is particularly useful for an electronic component mounting film carrier tape having a wiring pattern formed of a conductive metal foil on 0% or more of its surface. As described above, the warpage deformation of the film carrier tape for mounting electronic components is largely caused by the curing shrinkage stress generated during the heat curing of the solder resist, but not only this curing shrinkage but also other factors. It is caused by multiple actions. Therefore, if a factor other than the stress caused by the curing shrinkage of the solder resist is included in the film carrier tape for mounting electronic components as a stress that resists the curing shrinkage stress of the solder resist, the electronic components are cured even if the solder resist cures and shrinks. The warpage of the mounting film carrier tape can be reduced.

[0022]

Next, a method for manufacturing a film carrier tape for mounting electronic parts according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an example of a film carrier tape for mounting electronic components manufactured by the method of the present invention.

FIG. 2 is a process chart showing an example of a manufacturing process of the film carrier tape for mounting electronic parts of the present invention. FIG. 3 is a schematic perspective view having a notch showing an example of a reverse warpage imparting device used in the present invention. FIG. 4 and FIG.
It is a figure showing an example of a leveler unit arranged in a heating furnace in the present invention.

As shown in FIG. 1, a film carrier tape for mounting electronic parts manufactured by the present invention basically comprises a flexible insulating film 10 and a flexible insulating film 10.
An adhesive layer 12 provided on the surface, a wiring pattern 14 formed by etching a conductive metal attached to the flexible insulating film 10 by the adhesive layer 12, and a lead formed on the surface of the wiring pattern. And a solder resist 18 which has been applied and cured.

The flexible insulating film 1 used in the present invention
Numeral 0 is made of a flexible insulating resin film. Further, the flexible insulating film 10 has chemical resistance that is not affected by such a chemical because it comes into contact with an acid or the like at the time of etching, and heat resistance that does not deteriorate even by heating at the time of bonding. I have. Examples of the material for forming such a flexible resin film include polyester, polyamide, and polyimide. Particularly, in the present invention, it is preferable to use a film made of polyimide.

Examples of the polyimide film forming the flexible insulating film 10 include wholly aromatic polyimide synthesized from pyromellitic dianhydride and aromatic diamine.
A wholly aromatic polyimide having a biphenyl skeleton synthesized from biphenyltetracarboxylic dianhydride and an aromatic diamine can be exemplified. Particularly, in the present invention, a wholly aromatic polyimide having a biphenyl skeleton (eg, trade name: Upilex, manufactured by Ube Industries, Ltd.) is preferably used. The thickness of such a flexible insulating film 10 is usually in the range of 25 to 125 μm, preferably 25 to 75 μm. When polyimide is used as such a flexible insulating film, this polyimide has a water absorbency of about 3% or less, but the polyimide expands by absorbing water, and the contained water evaporates. Then, it has the property of shrinking.

The flexible insulating film 10 used in the present invention
Is provided with a sprocket hole 23, and if necessary, a device hole 21, an outer lead hole 22, and, if a bent portion is provided, a flex slit (not shown) or the like is formed at the bent position by punching. I have. Flexible insulating film 10 as described above
A conductive metal foil is stuck on the surface of the substrate with an adhesive layer 12, and a wiring pattern 14 made of a conductive metal is formed by etching a photoresist obtained by developing the conductive metal foil into a desired pattern as a masking material. Have been.

The adhesive 12 used for sticking the conductive metal foil for forming the wiring pattern to the flexible insulating film 10 as described above is heat-resistant, chemical-resistant, adhesively strong, Characteristics such as flexibility are required. Examples of the adhesive having such properties include an epoxy-based adhesive, a polyimide-based adhesive, and a phenol-based adhesive. Such an adhesive may be modified with a urethane resin, a melamine resin, a polyvinyl acetal resin, or the like, or the epoxy resin itself may be modified with a rubber. The thickness of the adhesive layer 12 is usually in the range of 8 to 23 μm, preferably 10 to 21 μm. Such adhesives are usually thermosetting, but many have a glass transition temperature (Tg), and in the case of an adhesive having such a glass transition temperature (Tg), this glass transition temperature (Tg) is usually in the range of 130 to 160 ° C. Specifically, for example, the glass transition temperature (Tg) of the epoxy adhesive is 130 to
The glass transition temperature (Tg) of the polyimide adhesive is about 150 to 160 ° C.

Such an adhesive may be applied to the surface of the flexible insulating film 10, or may be applied to the surface of the conductive metal foil. In addition, a conductive metal foil can be laminated using a resin equivalent to the resin forming the flexible insulating film 10. When the flexible insulating film 10 and the conductive metal foil are thermocompression-bonded using this adhesive, the adhesive tends to cure and shrink by thermocompression bonding. However, even when the adhesive is cured by heat compression, the adhesive softens somewhat by heating, and in such a softened state, the adhesive has a degree of freedom.

The conductive metal foil used in the present invention has conductivity and usually has a thickness of 6 to 150 μm, preferably 6 to 150 μm.
The metal foil is in the range of from 75 to 75 m, particularly preferably in the range of from 8 to 75 m, and more preferably in the range of from 8 to 50 m. Also, instead of directly laminating a metal foil having the above-mentioned thickness on a flexible insulating film, a very thin metal foil (for example, less than 6 μm) is adhered to the flexible insulating film. The conductive metal layer can be formed by depositing a metal on the surface of the attached ultrathin metal foil by, for example, an evaporation 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 a flexible insulating film to form a metal layer having a desired thickness (a metal plating layer, a metal deposition layer, or the like). )
May be formed.

In the present invention, a base film is produced by laminating a metal layer (such as a metal foil layer, a metal plating layer, a metal deposition layer, or a composite metal layer thereof) on the above-mentioned flexible insulating film. . Next, a photoresist is applied to the metal layer surface of the base film, a predetermined pattern is baked on the photoresist, unnecessary photoresist is removed, and a predetermined pattern is formed on the metal layer surface of the base film. The metal layer is etched using the pattern made of the photoresist as a masking material to form a wiring pattern made of a conductive metal foil.

That is, a phytoresist is applied to the surface of the metal layer of the base film, and a predetermined pattern is exposed and baked to form a portion soluble in an aqueous medium and a portion insoluble in an aqueous medium. By removing with an aqueous medium or the like, a masking material made of an insoluble photoresist can be formed on the surface of the metal layer. Here, the masking material made of an insoluble photoresist may be formed of a photoresist that cures by exposure, or, conversely, can be dissolved in a specific solvent such as an aqueous medium by exposure. After exposure using a photoresist, the photoresist may be formed by removing a portion of the photoresist solubilized by a specific solvent.

By bringing the base film masked by the photoresist into contact with the etching solution, the metal of the unmasked portion elutes, and the metal of the masked portion remains on the flexible insulating film. A wiring pattern made of the metal foil (or metal layer) that has not been eluted is formed on the flexible insulating film. As the etchant used here, a commonly used acidic etchant can be used.

In the wiring pattern thus formed, the pitch width of each inner lead is usually 20 to 50.
0 μm, preferably 25-100 μm.
Particularly, it is highly useful for a film carrier tape for mounting electronic components having a fine pitch of 20 to 80 μm. In addition,
The masking material (etchant-insoluble photoresist) after the etching in this manner can be removed by, for example, washing with an alkaline washing solution.

In particular, in the method for manufacturing a film carrier tape for mounting electronic parts according to the present invention, usually, a wiring pattern made of a conductive metal foil is formed on at least 30% of the surface of a flexible insulating film. It is highly useful as a method for preventing warpage of a film carrier tape. In the film carrier tape for mounting electronic parts of the present invention, after forming a wiring pattern made of a conductive metal foil or the like on the surface of the flexible insulating film by etching using a phytoresist as a masking material as described above, Then, a reverse warp is applied to the flexible insulating film on which the wiring pattern is formed, and / or the flexible insulating film on which the wiring pattern is formed is passed between the plurality of leveler rollers under heating.

First, a method of imparting a reverse warp to a flexible insulating film on which a wiring pattern is formed under heating will be described. A masking material is used when forming a wiring pattern on the flexible insulating film as described above. The photoresist used as the photoresist is removed by washing with alkali and water.
After removing the photoresist used as the masking material in this way, the flexible insulating film on which the wiring pattern has been formed is reversely warped under heating.

A device for applying a reverse warp to the flexible insulating film on which the wiring pattern is formed under the heating is as follows.
The device shown in FIG. 3 can be used. In this reverse warp imparting device, a heating furnace 54 provided with a heating means (not shown) is provided with a flexible insulating film having a wiring pattern formed thereon under heating by heating the flexible insulating film having the wiring pattern formed thereon. Curved in the width direction so that

Specifically, as shown in FIG.
In FIG. 4, the flexible insulating film on which the wiring pattern is formed is inserted into slits 58, 58 formed in a pair of side edge guides 57, 57 arranged at intervals slightly shorter than the tape width. The part is inserted. The pair of side edge guides 57, 57 are arranged at intervals shorter than the tape width, and the slits 58, 58 formed in the side edge guides 57, 57 also open obliquely upward. , Slits 5 formed in the side edge guides 57, 57
When the both sides of the flexible insulating film are inserted at 8,58, the flexible insulating film on which the wiring pattern is formed is bent in a convex shape with the surface on which the wiring pattern is formed facing upward. Become.

The length of the side edge guides 57, 57 can be appropriately set in accordance with the length of the heating furnace 54, but is usually about 5 to 50 cm, preferably about 30 to 50 cm. Are successively arranged about 1 to 6 pieces. As described above, the moving speed of the flexible insulating film 10 on which the wiring pattern is formed in the heating furnace 54 is usually 2 to 1
Since it is 0 cm / sec, preferably 3-5 cm / sec, the passing time of the flexible insulating film 10 on which the wiring pattern in a curved state is formed as described above is usually 5 to 100 sec, preferably 10 to 10 sec. ~ 60 seconds.

In this state, a heating means (not shown) provided in the heating furnace 54 normally operates for 100 to 30 minutes.
Heated to 0 ° C, preferably 150-200 ° C. In particular, when the adhesive has a glass transition temperature, it is preferable that the adhesive be applied to the glass at a temperature higher than the temperature. By heating the flexible insulating film on which the wiring pattern is formed in such a manner that the wiring pattern is reversely warped as described above, the adhesive bonding the wiring pattern to the flexible insulating film is somewhat softened. A slight displacement occurs between the flexible insulating film and the wiring pattern to maintain a curved shape with the wiring pattern facing upward, and the arrangement of the resin forming the adhesive by softening the adhesive layer is reduced. The restructured flexible insulating film on which the wiring pattern is formed undergoes reverse warpage deformation with the surface on which the wiring pattern is formed facing upward. In order to form and maintain the above-described reverse warpage deformation on the insulating film on which the wiring pattern is formed as described above, the area where the wiring pattern is formed on the surface of the flexible insulating film as described above is large. In addition, the above-mentioned reverse warpage deformation becomes larger, and therefore, it exists in the flexible insulating film on which the wiring pattern is formed as a stress that can sufficiently counteract the warpage deformation stress caused by the curing shrinkage of the solder resist.

Further, as described above, the wiring pattern can be formed also by drying and shrinking of the flexible insulating film due to evaporation of moisture contained in the flexible insulating film by heating in the heating furnace. The flexible insulating film is reversely warped with the surface on which the wiring pattern is formed as the upper surface. In the process after the formation of the wiring pattern, if the storage state is maintained in a dry state so as not to absorb the moisture in the air, the flexible insulating film also resists warpage deformation caused by the curing shrinkage of the solder resist. As a possible stress, the stress can be included in the flexible insulating film on which the wiring pattern is formed.

As described above, in the heating furnace 54, the side edge guides 5
The flexible insulating film 10 on which the sailboat pattern in which the reverse warpage is formed by using 7, 57 is usually formed so that the state in which the reverse warp is formed can be maintained after the reverse warp is formed. It is cooled to a temperature of less than 0 ° C, preferably 20-50 ° C. Further, in the method of the present invention, the wiring pattern is formed under heating together with the method of forming the reverse warpage using the side edge guides 57 in the heating furnace 54 as described above, or separately from this method. Flexible insulating film 1
By passing the flexible insulating film 10 on which the wiring pattern is formed between the leveler roller units 26 which are alternately displaced up and down with respect to the feeding direction of 0, the inner layer of the adhesive layer is formed. In addition to removing the stress causing the warpage deformation, the warpage deformation of the film carrier tape for mounting electronic components due to the curing shrinkage of the solder resist can be reduced by reconstructing the resin constituting the adhesive layer.

That is, the leveler unit 26 having the leveler rollers 34 to 40 alternately displaced up and down as shown in FIG. 4 and FIG. The flexible insulating film 10 on which the pattern is formed is vertically passed between the leveler rollers 34 to 41. The heating warp removing leveler unit 26 includes a pair of side plates 30 fixed by a support rod member 28, an introduction roller 32, a plurality of leveler rollers 34 to 40, and a discharge roller 42, each of which has a rotation support shaft 44. It is installed. The introduction roller 32, the leveler rollers 34 to 40, and the output roller 42 are rotatably mounted on the rotation support shaft 33 via bearings.

Each of the introduction roller 32, the leveler rollers 34 to 40, and the exit roller 42 has a step 45 for guiding the flexible insulating film 10 on which a wiring pattern is formed. Also, the side plate 3
0 has four engagement flanges 46 projecting therefrom.
These engagement flanges 46 are provided on the inner wall 48 of the heating furnace 54.
The leveler unit 26 can be removed from the heating furnace 54 by detachably engaging with the flange 50 formed in the heating furnace 54.

In the leveler unit 26, as shown in FIG. 5, the flexible insulating film 10 supplied to the heating furnace 54 and having the wiring pattern formed thereon is fed into the heating furnace 54 by an introduction roller as indicated by a chain line. The leveler rollers 34 to 40 are alternately displaced in the vertical direction with respect to the feeding direction C of the flexible insulating film 10 on which the wiring pattern is formed.

Then, as shown by a dashed line D in FIG.
The flexible insulating film 10 that has been introduced into the introduction roller 32 and has the wiring pattern formed thereon is wound so as to pass between the outer peripheral surfaces 34a to 40a located outside the leveler rollers 34 to 40, respectively. pass. With such a configuration, the flexible insulation is provided so as to oppose the stress in the solder resist which is likely to cause warpage deformation such that the processed surface of the solder resist becomes concave when the solder resist is cured (cured). The shrinking force of the film and the preformed force due to the reconstitution of the resin of the adhesive layer act to reduce the warpage of the obtained film carrier tape for mounting electronic components.

In order to increase the warpage preventing effect of the leveler unit 26 in the heating furnace 54, the flexible insulating film 10 on which the wiring pattern is formed is formed.
Leveler rollers 34 to 4 depending on the thickness, width and material of
It is desirable that the radius of curvature R of 0 is in the range of 1 to 5 cm, preferably 1.5 to 3 cm. In addition, leveler roller 3
It is desirable to set the amount of vertical displacement with respect to the feeding direction C of the flexible insulating film 10 on which the wiring patterns of 4 to 40 are formed, that is, the amount of pushing, in the range of 0 to 10 cm, preferably 1 to 3 cm. Further, the leveler roller 34
Separation distance between ~ 40 and 3 ~ 10cm, preferably 5 ~
It is desirable to set within the range of 8 cm.

The heating temperature of the flexible insulating film 10 on which the wiring pattern is formed using the heating furnace 54 is as follows:
100-300 ° C., preferably 15
When the adhesive has a glass transition temperature of 0 to 200 ° C., particularly when the adhesive has a glass transition temperature, it is preferable to heat the glass to a temperature higher than the temperature. The heating time at such a heating temperature is usually 10 to 300 seconds, preferably 60 to 120 seconds. The heating time can be appropriately set according to the length of the heating furnace 54 and the moving speed of the film carrier tape for mounting electronic components.

The side edge guide and the leveler roller as described above can be used alone or in combination. When both are used in combination, either the side edge guide or the leveler roller may be used first, but after flattening the flexible insulating film on which the wiring pattern is formed using the leveler roller, the side edge guide is used. By giving the reverse warpage using the guide, the warpage deformation in the longitudinal direction of the obtained film carrier tape for mounting electronic components can also be efficiently reduced.

Therefore, even if stress is generated due to the hardening of the solder resist, the warpage is caused by the stress inherent in the flexible insulating film on which the wiring pattern corrected by the side edge guide or the leveler roller is formed under heating. Is suppressed. In the present invention, the flexible insulating film on which the predetermined wiring pattern is formed as described above is given a reverse warp and / or after passing through a leveler roller,
In the next step, a solder resist 18 is applied except for the tip of the inner lead 15 and the tip of the outer lead 16 to be plated.

The solder resist coating solution used in the present invention is a coating solution having a relatively high viscosity in which a curable resin is dissolved or dispersed in an organic solvent. The curable resin contained in such a solder resist coating solution is an epoxy resin, an elastomer-modified epoxy resin, a urethane resin, an elastomer-modified urethane resin, a polyimide resin, an elastomer-modified polyimide resin, and an acrylic resin. It is preferable that the resin contains at least one resin component selected from the group consisting of resins. In particular, it is preferable to use a modified elastomer.

In the present invention, in addition to the resin components described above, the solder resist coating solution usually contains additives such as a curing accelerator, a filler, an additive, a thixotropic agent and a solvent. Can be added. Further, in order to improve the properties such as flexibility of the solder resist layer, fine particles having elasticity such as rubber fine particles can be blended.

Such a solder resist coating solution can be applied using a screen printing technique. The solder resist coating solution is applied except for portions that are usually plated in the next step, such as inner lead portions and outer lead portions. Such solder resist 1
The coating average thickness of No. 8 is usually in the range of 1 to 80 μm, preferably 5 to 50 μm.

After applying the solder resist in this way,
Usually, the solder resist is cured by heating,
It usually shrinks with this curing reaction. However,
In the electronic component mounting film carrier tape of the present invention,
Even when the solder resist cures and shrinks, there is a stress in the flexible insulating film on which the wiring pattern is formed, which can withstand the stress that causes such warpage deformation, so that both are offset and the film for mounting electronic components is removed. Warpage deformation that occurs in the carrier tape is significantly reduced.

In the present invention, after the solder resist is applied and cured while leaving the lead portion as described above, the lead portion exposed from the solder resist is plated. Examples of such plating include tin plating, gold plating, gold plating over nickel, nickel plating, silver plating, and solder plating. In the present invention, these treatments may be employed alone or in combination. it can.

The film carrier tape for mounting electronic parts manufactured as described above is preferably wound around a reel together with a flat spacer, and stored and transported. The flat spacer used here is formed of a flat resin film or the like having no unevenness on the front and back surfaces. Here, as the resin forming the flat spacer, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN): polyethylene, polypropylene and LLDPE
And polyolefins such as polyamide, polyimide, fluororesin (Teflon ^™ ) impregnated glass cloth and paper. The thickness of the flat spacer formed of such a resin is usually 50 μm or more, preferably 50 to 200 μm, and particularly preferably 75 to 150 μm.
It is in the range of μm.

The electronic component mounting film carrier tape manufactured as described above has a good applicability to fine patterns such as micro holes, and cuts and seals inner leads during mounting and assembling electronic components such as ICs. Accurate alignment can be performed without causing any trouble such as cracking of the resin and at the time of mounting on a printed circuit board such as a liquid crystal display element.

In the method of manufacturing a film carrier tape for mounting electronic components according to the present invention, the flexible insulating film having the wiring pattern formed thereon is treated before applying the solder resist, and then the solder resist is applied and cured. Further plating treatment can be performed.Before the above treatment, furthermore, after plating the wiring pattern surface with an undercoat, under heating, treatment using a side edge guide or a leveler roller, and then applying and curing a solder resist. Thereafter, the lead portion can be plated again.

The electronic component mounting film carrier tape obtained by the manufacturing method of the present invention is wound on a reel together with the flat spacer, and the electronic component mounting film carrier tape wound on the reel together with the flat spacer is reduced under reduced pressure. , The warpage of the film carrier tape for mounting electronic components can be further reduced.

The method for producing a film carrier tape for mounting electronic parts according to the present invention comprises a TAB tape, a T-BGA tape, an ASIC tape, a CSP tape and a liquid crystal element T.
It can be adopted when manufacturing an AB tape, a flexible wiring board for wire bonding, and the like.

[0061]

According to the method of manufacturing a film carrier tape for mounting electronic parts of the present invention, a process for forming a reverse warp on a flexible insulating film on which a wiring pattern is formed by using a side edge guide under heating. And / or after applying a treatment using a leveler roller, a solder resist is applied and cured on this wiring pattern, so that the flexible insulating film on which the wiring pattern is formed before the solder resist is applied. Has an inherent stress against shrinkage caused by the hardening of the solder resist, and the inherent stress and the hardening shrinkage stress of the solder resist cancel each other out, so that warpage deformation can be reduced.

In particular, in the production method of the present invention, when the leveler roller is used under heating, not only the warpage deformation occurring in the width direction of the film carrier tape for mounting electronic components but also the warpage deformation occurring in the longitudinal direction of the tape can be reduced. Becomes possible. Such a warpage reduction effect in the present invention becomes more conspicuous as the area of the wiring pattern formed of the conductive metal foil on the surface of the flexible insulating film is larger.

[0063]

Next, the present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited to these examples.

[0064]

Example 1 Width 4 with 12 μm thick adhesive layer formed
Device holes, sprocket holes, and cutting slits for outer leads were formed in a 8 mm, 75 μm thick polyimide film by punching. This adhesive layer was formed from an epoxy adhesive, and the epoxy adhesive had a glass transition temperature (Tg) of 150 ° C.).

Using this adhesive, an electrolytic copper foil having an average thickness of 25 μm was heated to a temperature of 160 ° C., and heated and pressed at a linear pressure of 3 kg / cm. Next, a photoresist was applied on the copper foil, and the photoresist was exposed and etched to form a wiring pattern made of the copper foil. The pitch width of the leads in the formed wiring pattern was 50 μm, and a wiring pattern made of copper foil was formed on 30% of the surface of the polyimide film.

After the wiring pattern was formed in this manner, the photoresist as a masking material was removed by washing with alkali and washing with water. The side edge of the polyimide film having the wiring pattern formed on the surface is shown in FIG.
A pair of side edge guides (50 cm in length) arranged in a heating furnace having a length of 3 m as shown in Fig. 4 was inserted into a slit in which six consecutive guides were placed. The pair of side edge guides is provided at the lower part of the slit.
The distance at the bottom was 40 mm, and thus the polyimide film was curved toward the upper surface on which the wiring pattern was formed.

The temperature of the heating furnace was set to 210 ° C., and the polyimide film having the wiring pattern formed on the surface set as described above was moved at a speed of 4 m / min in the heating furnace. In the polyimide film on which the wiring pattern processed and sent out as described above in the heating furnace was formed, a reverse warpage was formed in a convex shape with the surface on which the wiring pattern was formed facing upward.

Next, the wiring obtained as described above
A solder resist was applied on the surface of the pattern so that the thickness of the solder resist layer after curing was 20 μm while leaving a lead portion. This solder resist is made of an epoxy resin, and has a glass transition temperature (Tg) of 15
0 ° C. The polyimide film having the solder resist applied on the surface of the wiring pattern was heated stepwise to a temperature of 140 ° C. over one hour and heated to harden the solder resist.

After the solder resist was cured, a tin plating layer having a thickness of 0.2 μm was formed on the lead exposed from the solder resist layer. The thus produced film carrier tape for mounting electronic components had almost no warpage. This film carrier tape for mounting electronic components was stored on a reel together with a polyethylene terephthalate (PET) film having a thickness of 125 μm and a width of 48 mm at a temperature of 25 ° C. and a humidity of 60%, and the occurrence of warpage was observed. Almost no change in warpage over time was observed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a film carrier tape for mounting electronic components manufactured by a method of the present invention.

FIG. 2 is a process chart showing an example of a process for producing a film carrier tape for mounting electronic components of the present invention.

FIG. 3 is a partially cutaway perspective view showing an example of a device for applying a reverse warp to a film under heating used in the method of the present invention.

FIG. 4 is a side view showing an example of a leveler unit.

FIG. 5 is a plan view showing an example of the leveler unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Flexible insulating film (flexible insulating film in which wiring pattern was formed) 12 ... Adhesive layer 14 ... Wiring pattern 15 ... Inner lead 16 ... Outer lead 18 ...・ Solder resist 21 ・ ・ ・ Device hole 22 ・ ・ ・ Outer lead hole 23 ・ ・ ・ Sprocket hole 26 ・ ・ ・ Leveler unit 28 ・ ・ ・ Support rod member 30 ・ ・ ・ Side plate 32 ・ ・ ・ Introduction rollers 34,35, 36, 37, 38, 39, 40: Leveler roller 34a, 35a, 36a, 37a, 38a, 39a, 40a: Outer peripheral surface 42: Derivation roller 45: Step 46: Engagement Flange 48 ・ ・ ・ Inner wall of heating furnace 50 ・ ・ ・ Flange 52 ・ ・ ・ Sending part 54 ・ ・ ・ Heating furnace 57 ・ ・ ・ Side guide 58 ・ ・ ・ Slit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-111781 (JP, A) JP-A-10-178051 (JP, A) JP-A-8-45984 (JP, A) JP-A-2000-219267 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/60 311

Claims (9)

(57) [Claims] 1. A photoresist is applied to the surface of a conductive metal foil stuck on a flexible insulating film via an adhesive layer and exposed to light to form a desired pattern made of a photoresist. After forming a wiring pattern made of a conductive metal by etching the conductive metal foil using the pattern as a masking material, a solder resist is formed.
Before coating, (A) a flexible insulating film on which the wiring pattern is formed
Step surface wiring pattern has been formed Ru adversely warped flexible insulating film wiring pattern is formed by shaping curved in the width direction in a convex shape so that the upward under heating, and And / or (B) a flexible insulating film on which the wiring pattern is formed
To under heating, allowed to respect the feeding direction of the flexible insulation film wiring pattern is formed, the wiring pattern between the plurality of leveler rollers arranged displaced alternately up and down is formed Ru passed through a fLEXIBLE insulating film process, by going through the 30% or more of the flexible insulating film
Wiring pattern made of conductive metal foil is formed on the surface of
Stress that can resist warping is applied to the flexible insulating film
Zaisa allowed, then the film carrier tape manufacturing method of the warp deformation is reduced, characterized in that to the coating to cure the solder resist leaving a joint terminal portion on the surface of the wiring pattern. 2. The method for manufacturing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the thickness of the adhesive is in the range of 8 to 23 μm. 3. When the flexible insulating film on which the wiring pattern is formed by projecting a curved shape in the width direction so that the surface on which the wiring pattern is formed faces upward, 2. The method for producing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the tape is heated to 100 to 300 [deg.] C. 4. The method for producing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the heating time of the heating is 30 to 200 seconds. 5. The method according to claim 5, wherein after the heating, the flexible insulating film on which the wiring pattern having the reverse warpage is formed or the flexible insulating film on which the wiring pattern passing through the leveler roller is formed is cooled. Claim 1,
5. The method for producing a film carrier tape for mounting electronic components according to claim 3 or 4, wherein the warpage is reduced. 6. The electronic component mounting film according to claim 1, wherein the solder resist has an average thickness after curing within a range of 10 to 40 μm. Manufacturing method of carrier tape. 7. The conductive metal foil has an average thickness of 6 to 15.
2. The method for producing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the thickness is within a range of 0 [mu] m. 8. The flexible insulating film having an average thickness of 2
2. The method for producing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the thickness is in the range of 5 to 125 [mu] m. 9. The method for manufacturing a film carrier tape for mounting electronic parts with reduced warpage according to claim 1, wherein the wiring pattern to which the solder resist is not applied is plated.