JP2000012625A - Film carrier tape for mounting electronic parts and manufacture of film carrier tape for mounting electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent camber deformation of a film carrier tape by pasting a conductive foil on an insulating film having a thickness less than specified using an adhesive layer having an average thickness less than specified for the insulating film, and etching the conductive foil to obtain desired interconnect patterns. SOLUTION: An insulating film 10 having thickness less than 75 μm is formed from fully aromatic polyimide material synthesized from pyromellitic-2-anhydride and aromatic diamine, fully aromatic polyimide having biphenyl skeleton synthesized from biphenyltetracarbonic-2-anhydride and aromatic diamine, or the like. An electrolytic copper foil 14 of 9 μm thick is pressure contacted under a heated condition via an adhesive layer 12 of epoxy resin, phenol resin, or the like, having an average thickness less than 15% of the thickness of the insulating film 10, and is etched to obtain desired interconnect patterns. In this case, camber ratio in the width direction of the tape with respect to the tape width is kept lower than 2.5% of the tape width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film carrier tape (TAB (TB) for mounting electronic parts such as ICs or LSIs.
ape Automated Bonding) tape or T-BGA (Tape
Ball Grid Array) tape, in the present invention, "TAB
The description "tape" includes these) and a method for producing the film carrier tape. More specifically, the present invention relates to a film carrier tape in which warpage of a film carrier tape caused by an adhesive used when attaching a conductive foil is reduced, and a method of manufacturing such a film carrier tape having less warpage.

[0002]

BACKGROUND OF THE INVENTION In recent years, electronic devices such as notebook personal computers have become smaller and lighter. Semiconductor I
The wiring of C is further miniaturized. IC or LSI
There is also a high demand for finer pitch wiring patterns formed on a TAB tape used for mounting the IC on a printed wiring board or connecting a drive IC of a liquid crystal display device to a liquid crystal substrate.

A TAB tape has a conductor foil such as a copper foil adhered to the surface of the above-mentioned insulating film via an adhesive formed by an epoxy-based adhesive or the like, and the conductor foil is formed into a desired pattern. It is manufactured by etching.

In order to reduce the weight or fine the pitch, it is necessary to reduce the thickness of an insulating film (eg, a polyimide film) as a base material. That is, in the conventional TAB tape, the thickness (average thickness) of the insulating film is mainly 125 μm,
With the recent reduction in weight or fine pitch, use of an insulating film having a thickness of 75 μm is being studied.

[0005] The polyimide forming the insulating film and the adhesive made of epoxy resin and the like have different characteristics due to heating when the conductive foil is bonded. In general, epoxy resin is more likely to be heated than polyimide when heated. Large shrinkage. When a conventional polyimide film having a thickness of 125 μm or a thick insulation film exceeding 75 μm is used, the heat shrinkage of the epoxy resin is absorbed by the insulation film due to the high rigidity of the insulation film, so that it becomes apparent. There was little to do. However, for example, 75μ
m, especially when a thin insulating film having a thickness of less than 75 μm is used, the stress generated due to the heat shrinkage of the epoxy resin as the adhesive becomes TAB.
Appears as tape warpage.

[0006] As described above, with the miniaturization and weight reduction of electronic equipment, the wiring pattern formed on the TAB tape has a remarkably fine pitch of several tens of μm or less, and bonding can be performed even by slight deformation of the TAB tape. Easy to cause defects. The deformation of the TAB tape due to the difference in thermal characteristics between the insulating film and the adhesive is due to the characteristics of both, and a polyimide film is used as the insulating film and an epoxy resin is used as the adhesive. Therefore, it is considered to be a problem that is difficult to avoid, and once warpage occurs, it cannot be removed in a subsequent process until the product is completed.

[0007] In addition to the adhesive, the cause of warpage of the TAB tape is caused by heat shrinkage when the solder resist is cured. The applicant of the present invention reduces the occurrence of warpage due to the solder resist. Application for method and device for reducing warpage
No. 289210). In the invention described in this specification, a TAB tape is formed by forming a reverse warp in an insulating film by heating while imparting a reverse warp to the insulating film, thereby canceling the warp caused by the solder resist and the reverse warp. In order to reduce the deformation that occurs in However, this method is effective when the applied reverse warp coincides with the warp caused by the solder resist.
When the amount of warpage is small, it is very difficult to form a reverse warp corresponding to such a small warp. Therefore, this method is less effective against warpage due to the adhesive.

Further, Japanese Patent Application Laid-Open No. 4-196554 discloses a flexible tape substrate in which the thickness of an adhesive is reduced in a flexible three-layer substrate in which a copper foil is laminated on a film. ing. By thinning the adhesive in this manner, the heat generated during the heating and pressing when bonding the outer leads to the electrodes formed on the glass substrate using the anisotropic conductive adhesive causes the pattern to be formed by the movement of the adhesive. The dimensional movement is reduced, and the combined dimensional accuracy of the conductive portions is improved, thereby improving the bonding accuracy. However, this publication does not describe the thickness of the adhesive and the insulating film for preventing the TAB tape from being warped in relation to the adhesive and the insulating film. This publication also states that the effect of dimensional stress on the copper foil pattern due to heating during anisotropic conductive bonding can be reduced by making the adhesive thinner. That is, in this publication,
It has been shown that the stress existing in the adhesive layer during the anisotropic conductive bonding becomes apparent so as to move the wiring pattern. Since the insulating film is thick, the stress is embedded in the adhesive and the TAB tape is used. The whole has not been transformed.

Also, Japanese Patent No. 2734184 discloses that
In a tape carrier formed by bonding a copper foil on an insulating film using an adhesive and forming a wiring pattern, the thickness of the adhesive is set to 3 to 7 μm, and the roughened surface on the bonding side of the copper foil is The invention of a TAB tape carrier characterized by having an average roughness Ra of 0.1 to 0.4 μm is disclosed. In this gazette, a relatively thick polyimide film of 125 μm to 75 μm or the like is used as a generally used insulating film.

Further, this publication discloses that chlorine ions and ammonia generated from the epoxy resin adhesive corrode the copper foil, which cause short-circuiting due to migration, that the cured epoxy resin is hard,
The AB tape breaks when bent, and the wiring pattern peels off due to the occurrence of such cracks. The cured epoxy resin is easily cracked, becomes powdery, and the powdered epoxy resin becomes It has been mentioned that the adhesion to the wiring pattern surface causes pattern defects. By setting the thickness of the adhesive layer to 3 to 7 μm, corrosion of the wiring pattern, short circuit, cracking of the adhesive layer,
It is described that occurrence of pattern defects due to adhesion of powdered epoxy resin can be prevented.

However, in this publication, since a relatively thick polyimide film having a thickness of 125 μm to 75 μm or the like is used as an insulating film, most of the stress due to heat shrinkage is internal to the adhesive layer as internal stress, and the TAB tape has Deformation such as warpage is unlikely to occur.

[0012]

SUMMARY OF THE INVENTION The present invention provides a method of preventing warpage of a TAB tape caused by the heat shrinkage of an adhesive when a thin insulating film is used, and a thin TAB tape with reduced warpage. It is intended to be.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a method for forming a desired wiring pattern on a thin insulating film having an average thickness of 75 μm or less via an adhesive layer having an average thickness of 15% or less of the average thickness of the insulating film. The present invention is directed to a film carrier tape for mounting an electronic component, in which a conductor foil etched in a manner as described above is adhered and warpage is reduced.

[0014] The present invention also provides a thin insulating film having an average thickness of not more than 75 µm on at least one surface thereof.
An adhesive film prepared in advance to an average thickness of 15% or less of the average thickness of the insulating film and a conductive foil are pasted through the adhesive film, and the conductive foil is etched into a desired wiring pattern. A method for manufacturing a film carrier tape for mounting electronic components with reduced warpage.

The inventor of the present invention has found that, in a film carrier tape for mounting electronic components, the thickness of the insulating film is 75 μm or less, and the warp deformation of the TAB tape specifically caused by using a thin insulating film is prevented, and The present invention was completed by finding the necessary and sufficient layer thickness of the adhesive layer for the thickness of the insulating film to securely adhere the wiring pattern to the insulating film. That is, when a thin insulating film having an average thickness of 75 μm or less is used, the thickness of the adhesive layer is set to 15% of the thickness of the insulating film.
By setting as follows, even if the adhesive layer is heated and contracted by curing the adhesive layer, the contraction stress does not appear as a large warping deformation that hinders the bonding, and furthermore, the wiring pattern Can be securely bonded to the insulating film.

Such a film carrier tape for mounting electronic parts is manufactured by previously manufacturing an adhesive film having an average thickness of 15% or less of the thickness of the insulating film in accordance with the thickness of the insulating film to be used. Preferably, the adhesive film is manufactured by attaching the adhesive film to the surface of the insulating film to form an adhesive layer. By forming an adhesive layer using an adhesive film prepared in advance to a predetermined thickness in this manner, it is possible to form an adhesive layer having uniform and good adhesiveness. Also, by using such an adhesive film, warpage can be further prevented. Also, by manufacturing the adhesive film in advance in this way, it is possible to prevent the formed adhesive layer from containing a volatile component such as a solvent, thereby more surely forming the wiring pattern on the insulating film. Can be adhered to. In addition, there is no fear of environmental pollution due to a solvent or the like.

[0017]

Next, the film carrier tape for mounting electronic components of the present invention and the method for producing the film carrier tape for mounting electronic components will be described in detail.

FIG. 1 is a plan view schematically showing an example of a film carrier tape for mounting electronic parts according to the present invention.
FIG. 2 is an enlarged view of a portion A in FIG. FIG. 3 is a partial sectional view of the tape taken along line XX shown in FIG. FIG. 4 is a diagram illustrating a method for measuring the amount of warpage of the film carrier tape for mounting electronic components according to the present invention.

As shown in FIGS. 1 to 3, the film carrier tape 1 for mounting electronic components of the present invention comprises a thin insulating film 10, an adhesive layer 12, and wiring patterns 15 and 16 made of a conductive foil 14. And these are stacked in this order.

The thin insulating film 10 on which the wiring pattern is formed is made of a flexible resin film. In addition, the insulating film has chemical resistance not to be attacked 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. Examples of such a resin include glass epoxy, BT resin, polyester, polyamide, and polyimide. Particularly, in the present invention, it is preferable to use a film made of polyimide. Examples of the polyimide film constituting the insulating film 10 formed of such a resin include a wholly aromatic polyimide synthesized from pyromellitic dianhydride and an aromatic diamine, and biphenyltetracarboxylic dianhydride and an aromatic diamine. And a wholly aromatic polyimide having a biphenyl skeleton synthesized from an aromatic diamine. 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.

In the film carrier tape for mounting electronic parts of the present invention, the insulating film 10 is thinner than those generally used in the past, and the present invention has an average thickness (T _b ) of the insulating film 10. , 75 μm or less can be reduced. In particular, in the present invention, the effectiveness is high when the average thickness (T _b ) of the insulating film 10 is less than 75 μm, preferably 20 to 75 μm, and the average thickness (T _b ) is 20 to 70 μm. This is particularly effective in some cases. When using such a thin insulating film, by forming an adhesive layer,
Warpage deformation is likely to occur, and there has not been known a method for effectively reducing warpage generated when an adhesive layer is laminated on such a thin insulating film.

Incidentally, such a thin insulating film 10
As shown in FIG. 1, the opening of the sprocket hole 21 and the like is usually formed by punching or the like. An adhesive layer is formed on the surface of the thin insulating film 10 as described above, and the conductive foil 14 is adhered by the adhesive layer 12.

In the present invention, the average thickness (T _a ) of the adhesive layer 12 needs to be 15% or less of the average thickness (T _b ) of the thin insulating film 10. In this way, the average thickness (T _a ) of the adhesive layer 12 is controlled to 15% or less, preferably 0.5 to 14% of the average thickness (T _b ) of the thin insulating film 10. By doing
The warpage of the film carrier tape for mounting electronic components according to the present invention due to the stress generated in the adhesive layer can be reduced to a level that does not hinder bonding. That is, as shown in FIG. 4, when an electrolytic copper foil 14 having an average thickness of 9 μm is heat-pressed onto the thin insulating film 10 via an adhesive layer 12, the warpage ratio (n) to the tape width in the tape width direction is determined. / M × 100) can be reduced to 3.5% or less, preferably 2.5% or less of the tape width (m). For example, as an insulating film, the width (m) is 4
When the polyimide film 10 having a thickness of 8 mm is used, the warpage ratio (n / m × 100) is 3.5% or less, so that the measured warpage amount (n) can be 1.68 mm or less. . In the present invention, the warpage rate (n / m × 10
4), as shown in FIG. 4, an insulating film 10 having a 9 μm-thick electrolytic copper foil 14 adhered to the upper surface of a base 31 having a smooth surface, and the insulating film 10 The insulating film 1 is placed so as to be in contact with the
The height (that is, the amount of warpage (n)) at which the end in the length direction of 0 is lifted from the surface of the base 31 is measured, and the amount of warpage (n)
Is expressed as a percentage of the width (m) of the insulating film. The warp rate (n
/ M × 100) is controlled to 3.5% or less, preferably 2.5% or less, so that in actual bonding, the displacement of the electrodes becomes sufficiently small with respect to the lead width.
Also, when releasing the presser of the tape after bonding,
It is possible to reduce the stress on the leads caused by the warpage, and it is possible to significantly reduce the occurrence of bonding failure and lead breakage during mounting.

In calculating the warp rate, the adhesive layer 12 is formed on the entire surface of the thin insulating film 10 except for the portion where the sprocket holes 21 are formed, and the upper surface of the adhesive layer 12 is formed. Is a value measured for a test piece obtained by arranging an electrolytic copper foil having a thickness of 9 μm so that the mat surface faces the adhesive layer 12 and curing and bonding the same. The same applies to an actual electronic component mounting film carrier tape. The measured amount of warpage (n) generally takes a smaller value than the amount of warpage (n) measured using the test piece, since the electrolytic copper foil has been etched.

The present inventor has determined that the warpage (n)
Found that the thickness varies with the thickness of the insulating film, the thickness of the adhesive layer, and the relative value.Moreover, the amount of warpage does not hinder the bonding, and has sufficient adhesive strength to cope with the narrow pitch. The present invention has been completed by selecting the relative thickness of the adhesive layer necessary and sufficient for bonding the conductive foil to the thin insulating film.

Accordingly, as the adhesive used in the present invention, an adhesive which is generally used as an adhesive for a film carrier tape for mounting electronic parts can be used. The adhesive used for the film carrier tape for mounting electronic components generally needs to have excellent properties such as heat resistance, chemical resistance, adhesive strength, and flexibility. Examples of the adhesive having such characteristics include an epoxy resin adhesive and a phenol resin adhesive. Particularly in the present invention, the effectiveness is high when an epoxy resin-based adhesive is used. The epoxy resin adhesive suitably used in the present invention 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.

Such an adhesive is heat-curable.
For example, when an epoxy resin-based adhesive is used as the adhesive, the epoxy resin adhesive should be formed by applying such that the thickness of the adhesive layer when drying the thin insulating film is within the above range. However, it is preferable that the epoxy resin is adhered to the surface of the insulating film in the form of an adhesive film formed into a film such that the layer thickness is within the above range. That is, in general, when an epoxy resin is directly applied on a thin insulating film due to its high viscosity, it is extremely difficult to apply the same viscosity to have a layer thickness in the above range with the same viscosity. . Therefore, usually, a coating solution prepared by dissolving or dispersing the epoxy resin in an organic solvent is prepared, and after applying the coating solution,
It is necessary to adopt a method of removing the solvent. When using a coating liquid, it is necessary to incorporate the step of removing the solvent from the coating layer and the step of recovering the removed solvent into the step of the film carrier tape for mounting electronic components, which makes the process and the apparatus complicated. It is disadvantageous. Further, the adhesive layer formed by applying the coating liquid has fluidity until the solvent is removed, and depending on the treatment after the application, the uniformity of the adhesive layer may be impaired. Furthermore, when viewed microscopically, the portion from which the solvent has been removed tends to have a coarse epoxy resin as an adhesive, making it difficult to form a uniform adhesive layer as a whole. In contrast, when an epoxy resin is applied to another base tape and an adhesive film prepared in advance is attached to the insulating film, the adhesive layer can be formed in a single step. In addition, since no organic solvent is used in this step, equipment is advantageous. Further, by manufacturing the adhesive film in advance, the thickness of the adhesive film can be accurately controlled, so that the uniformity of the formed adhesive layer is also improved. If the adhesive film is compressed when the adhesive film is manufactured, a uniform adhesive film can be manufactured as a whole.

Therefore, when manufacturing the film carrier tape for mounting electronic components of the present invention, it is preferable that the adhesive layer is formed using an adhesive film prepared in advance. In the electronic component mounting film carrier tape of the present invention, the wiring pattern 14 is formed by attaching the conductive foil 14 to the surface of the insulating film 10 using the adhesive 12 and etching the attached conductive foil into a desired pattern. It is formed by doing. The wiring pattern includes an inner lead 15 and an outer lead 16.
Reference numeral 5 denotes a portion extending into the device hole 20 and connecting to a bump electrode of the device. The pitch width (P ₀ ) of the inner leads 15 is usually 200 μm or less, preferably 10 to 100 μm, particularly preferably 20 μm. ５０50 μm, which is smaller than the pitch width of the inner leads formed on the conventional film carrier tape for mounting electronic components. The width (W ₀ ) of the inner leads 15 formed at such a pitch width is usually 100 μm or less, preferably 10 to 50 μm, particularly preferably 15 to 45 μm. 15,1
The gap width (S ₀ ) of No. 5 is usually 100 μm or less, preferably 10 to 50 μm, particularly preferably 15 to 45 μm.

The outer lead 16 extends from the inner lead 15 toward the outside of the tape.
Usually formed of conductor foil wider than the inner leads,
It extends radially outward from the inner leads arranged in parallel.

In the present invention, the inner lead means a wiring pattern portion arranged in parallel for connection to an electrode of a device, and a wiring pattern outside from a portion radially bent outward is defined as an outer lead. .

Examples of the conductor foil to be adhered as described above include copper and aluminum. Further, a small amount of another metal component such as indium can be added to the conductor foil, particularly the copper foil. In the present invention, it is preferable to use a copper foil as the conductor foil. Copper foil materials include electrolytic copper foil and rolled copper foil, and any of the copper foil materials can be used in the present invention.

The average thickness (T _p ) of such a conductor foil is:
Usually, 70 μm or less, preferably 4 to 70 μm, particularly preferably 4 to 40 μm, and more preferably 4 to 20 μm.
m, most preferably in the range of 4 to 15 μm. In particular, in the case of a fine pitch TAB tape that has recently attracted attention, an electrolytic copper foil having an average thickness (T _p ) of usually 4 to 20 μm, preferably 4 to 15 μm is used.

After bonding the conductive foil on the insulating film using an adhesive as described above, a photosensitive resin (resist) is applied to the surface of the conductive foil. Next, after baking and developing the wiring pattern formed on the photosensitive resin, the uncured resin is removed and etched to form a wiring pattern. After the etching, the photosensitive resin (resist) is removed, and the surface of the inner lead with which the bump electrode contacts is plated. Examples of the plating include tin plating and gold plating.

Further, the film carrier tape for mounting electronic parts of the present invention is coated with a solder resist as required. In addition, the film carrier tape for mounting electronic components of the present invention shown in FIG. 1 shows a form in which a device hole 20 for mounting a device is provided. The device may be mounted by providing a slit in the insulating film corresponding to the bump.

[0035]

According to the present invention, there is provided a film carrier tape for mounting electronic parts, in which warpage is reduced by using a thin insulating film accompanying a reduction in weight and fine pitch.

That is, in the film carrier tape for mounting electronic parts of the present invention, when a thin insulating film having a thickness of 75 μm or less is used, the thickness of the adhesive layer is set to 15% or less of the thickness of the insulating film. This control reduces the warpage of the film carrier tape for mounting electronic components. By setting the thickness of the adhesive layer to the insulating film as described above, the electronic component mounting film carrier tape is less likely to be warped and the wiring pattern can be securely bonded to the insulating film.

Therefore, according to the film carrier tape for mounting electronic parts of the present invention, a short circuit due to a bonding failure is unlikely to occur. In addition, lead breakage during bonding hardly occurs.

Moreover, in the film carrier tape for mounting electronic parts of the present invention, the thickness of the insulating film can be reduced, and the thickness of the adhesive layer can be correspondingly reduced, which is suitable for weight reduction and bending applications.

Furthermore, the film carrier tape for mounting electronic parts of the present invention is suitable for fine pitch. Further, the electronic component mounting film carrier tape of the present invention is preferably formed by using an adhesive film whose adhesive layer has been adjusted to a predetermined thickness in advance, and is manufactured by a process using a conventional apparatus. be able to. Further, according to the method of the present invention, no environmental pollution is caused by the organic solvent when forming the adhesive layer.

[0040]

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

[0041]

Example 1 As an insulating film, a width (m) of 48 mm,
50 μm thick (T _b ) polyimide film (trade name:
This polyimide film and an epoxy resin adhesive film whose thickness (T _a ) has been adjusted to 1 μm are bonded together using UPILEX, manufactured by Ube Industries, Ltd.). (T _p ) An electrolytic copper foil having a thickness of 9 μm was placed and heated and pressed at 150 ° C. In this laminate, the relative thickness of the adhesive layer to the insulating film (T
_a / _Tb × 100) is 2.0%.

When the amount of warpage (n) of the laminate obtained as described above was measured in accordance with the method shown in FIG. 4, it was 0.4 mm, and the warpage ratio (n) with respect to the width (m) of the insulating film was measured. / M × 100) was 0.83%.

FIG. 1 shows the laminated body manufactured as described above.
As shown in FIG. 5, a commercially available photoresist is applied, the pitch width (P ₀ ) of the inner leads is 50 μm, the width (W ₀ ) of the inner leads 15 is 25 μm, and the gap between the adjacent inner leads 15 After exposing the pattern so that the width (S ₀ ) becomes 25 μm, etching is performed to form a wiring pattern as shown in FIG. 1, and a tin plating layer having a thickness of 0.4 μm is formed on the bonding portion according to a conventional method. A film carrier tape for mounting electronic components was manufactured.

With respect to the thus formed film carrier tape for mounting electronic components, the failure rate (ILB) of the inner lead bonding portion and the bonding failure rate (OLB) of the outer lead bonding portion were measured.

The results are shown in Table 1.

[0046]

In Example 2 Example 1, in place of the thickness (T _a) 1μm epoxy resin adhesive film, except for using the adjusted thickness of (T _a) to 5μm epoxy resin adhesive film A laminate was produced in the same manner, and a film carrier tape for mounting electronic components was produced using the laminate. The relative thickness (T _a / T _b × 100) of the adhesive layer to the insulating film in this laminate is 10.0%.

With respect to the film carrier tape for mounting electronic parts manufactured from the laminate obtained as described above, the amount of warpage (n) measured in the same manner as in Example 1 was 1.
0 mm, and the warpage ratio (n / m × 100) with respect to the width (m) of the insulating film was 2.08%. The bonding failure rate of the film carrier tape for mounting electronic components was measured.

The results are shown in Table 1.

[0049]

In Comparative Example 1 Example 1, in place of the thickness (T _a) 1μm epoxy resin adhesive film, except for using the adjusted thickness of (T _a) to 10μm epoxy resin adhesive film A laminate was produced in the same manner, and a film carrier tape for mounting electronic components was produced using the laminate. The relative thickness (T _a / T _b × 100) of the adhesive layer to the insulating film in this laminate was 20.0%
It is.

The warpage amount (n) of the film carrier tape for mounting electronic components manufactured from the laminate obtained as described above, which was measured in the same manner as in Example 1, was 4.
0 mm, and the warpage ratio (n / m × 100) with respect to the width (m) of the insulating film was 8.33%, and the warpage ratio was extremely high. The bonding failure rate of the film carrier tape for mounting electronic components was measured.

The results are shown in Table 1.

[0052]

Embodiment 3 In Embodiment 1, the thickness (T _b ) is 50 μm.
Thickness (T _b ) instead of the polyimide film of 25
A laminate was produced in the same manner except that a μm polyimide film was used, and a film carrier tape for mounting electronic components was produced using this laminate. The relative thickness of the adhesive layer to the insulating film in this laminate (T _a / T _b ×
100) is 4.0%.

With respect to the film carrier tape for mounting electronic parts manufactured from the laminate obtained as described above, the amount of warpage (n) measured in the same manner as in Example 1 was 0.3.
The warp rate (n / m × 100) with respect to the width (m) of the insulating film was 1.67%. The bonding failure rate of the film carrier tape for mounting electronic components was measured.

The results are shown in Table 1.

[0055]

In Comparative Example 2 Example 3, in place of the thickness (T _a) 1μm epoxy resin adhesive film, except for using the adjusted thickness of (T _a) to 5μm epoxy resin adhesive film A laminate was produced in the same manner, and a film carrier tape for mounting electronic components was produced using the laminate. The relative thickness (T _a / T _b × 100) of the adhesive layer to the insulating film in this laminate is 20.0%.

The warpage amount (n) of the film carrier tape for mounting electronic components manufactured from the laminate obtained as described above, which was measured in the same manner as in Example 1, was 4.
0 mm, and the warpage ratio (n / m × 100) with respect to the width (m) of the insulating film was 8.33%, and the warpage ratio was extremely high. The bonding failure rate of the film carrier tape for mounting electronic components was measured.

The results are shown in Table 1.

[0058]

In Comparative Example 3 Example 3, in place of the thickness (T _a) 1μm epoxy resin adhesive film, except for using the adjusted thickness of (T _a) to 10μm epoxy resin adhesive film A laminate was produced in the same manner, and a film carrier tape for mounting electronic components was produced using the laminate. The relative thickness (T _a / T _b × 100) of the adhesive layer to the insulating film in this laminate was 40.0%
It is.

The warpage amount (n) of the film carrier tape for mounting electronic parts manufactured from the laminate obtained as described above, which was measured in the same manner as in Example 1, was 8.
0 mm, and the warpage rate (n / m × 100) with respect to the width (m) of the insulating film was 16.67%, and the warpage rate was significantly increased. The bonding failure rate of the film carrier tape for mounting electronic components was measured.

The results are shown in Table 1.

[0061]

Embodiments 4 to 6 In the embodiment 1, the thickness ( _Tb ) is 50.
A polyimide film having a thickness (T _b ) of 75 μm was used instead of the polyimide film having a thickness of μm, and an epoxy resin adhesive [(T _{a
/ T b × 100) = 1.3} %, Example 4, an epoxy resin adhesive having a thickness of _{5μm [(T a / T b} × 100) = 6.6%, Example 5], thickness 10μm Epoxy resin adhesive [(T
_a / _Tb × 100) = 13.3%, Example 6], except that the laminated body was manufactured, and a film carrier tape for mounting electronic components was manufactured using the laminated body.

For the film carrier tape for mounting electronic parts manufactured from the laminate obtained as described above, the amount of warpage (n) in Example 4 measured in the same manner as in Example 1 was 0.2 mm. The warpage rate (n / m × 100) with respect to the width (m) of the insulating film was 0.42%, the warpage amount (n) in Example 5 was 0.7 mm, and the width (m) with respect to the width (m) of the insulating film. Warpage rate (n / mx
100) is 1.46%, the amount of warpage (n) in Example 6 is 1.2 mm, and the warpage rate (n / m × 100) with respect to the width (m) of the insulating film is 2.50%. Was.

The bonding failure rate of the film carrier tape for mounting electronic components was measured. The results are shown in Table 1.

[0064]

[Table 1]

The relative thickness of the adhesive layer shown in Table 1 above,
FIG. 5 shows the relationship between the amount of warpage and the warpage rate. As is clear from FIG. 5, the increase in the amount of warpage and the warpage ratio is small up to a relative thickness of the adhesive layer of 15%, but the relative thickness of the adhesive layer is 1%.
If it exceeds 5%, the warp amount and the warp ratio agent layer relative thickness 15
% Is a critical value for the amount of warpage and the warpage rate.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an example of a film carrier tape for mounting electronic components according to the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a partial sectional view of the tape taken along line XX shown in FIG. 1;

FIG. 4 is a view showing a method for measuring the amount of warpage of the film carrier tape for mounting electronic components according to the present invention.

FIG. 5 is a graph showing the relationship between the relative thickness of the adhesive layer and the amount of warpage and the warpage ratio.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic component mounting film carrier tape 10 ... Insulating film 12 ... Adhesive layer 14 ... Conductor foil 15 ... Inner lead 16 ... Outer lead 21 ... Sprocket hole

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Claims (14)

[Claims] 1. A desired wiring pattern is etched on a thin insulating film having an average thickness of 75 μm or less via an adhesive layer having an average thickness of 15% or less of the average thickness of the insulating film. A film carrier tape for mounting electronic components with reduced warpage to which a conductive foil is adhered. 2. The method according to claim 1, wherein said thin insulating film has an average thickness of 20.
2. The film carrier tape for mounting electronic parts according to claim 1, wherein the film carrier tape is a polyimide film having a thickness of from 75 to 75 [mu] m. 3. The method according to claim 1, wherein the average thickness of the adhesive layer is in the range of 0.5 to 14% of the average thickness of the thin insulating film. Film carrier tape for mounting electronic components. 4. The film carrier tape according to claim 1, wherein said adhesive layer is formed of a film made of a thermosetting resin. 5. The carrier tape for mounting electronic parts according to claim 1, wherein said conductive foil is an electrolytic copper foil having an average thickness of 70 μm or less. 6. A warp ratio in the width direction of the tape when an electrolytic copper foil having an average thickness of 9 μm is thermocompression-bonded to the thin insulating film via an adhesive layer, is not more than 3.50% of the tape width. The film carrier tape for mounting electronic components according to claim 1, wherein: 7. The film carrier tape according to claim 1, wherein a pitch width of a narrowest portion of the wiring pattern formed by the conductive foil is 200 μm or less. 8. An adhesive film previously prepared on at least one surface of a thin insulating film having an average thickness of 75 μm or less and having an average thickness of 15% or less of the average thickness of the insulating film, and the adhesive film. A method for producing a film carrier tape for mounting electronic components with reduced warpage by attaching a conductor foil via a film and etching the conductor foil into a desired wiring pattern. 9. The thin insulating film having an average thickness of 20
9. The method according to claim 8, which is a polyimide film of .about.75 .mu.m. 10. The average thickness of the previously prepared adhesive film is 0.5 to 1 of the average thickness of the thin insulating film.
10. A method according to claim 8 or claim 9, wherein the value is in the range of 4%. 11. The method according to claim 8, wherein said adhesive film comprises a thermosetting resin. 12. The method according to claim 8, wherein said conductive foil is an electrolytic copper foil having an average thickness of 70 μm or less. 13. When the electrolytic copper foil having an average thickness of 9 μm is heat-pressed to the thin insulating film via an adhesive film, the warp ratio in the width direction of the tape becomes 3.5 times the tape width.
9. The method according to claim 8, wherein the value is 0% or less. 14. The method according to claim 8, wherein the pitch width of the narrowest part of the wiring pattern formed by the conductive foil is 200 μm or less.