JP2004031685A - Method for manufacturing chip on film carrier tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a chip on film carrier tape which can well convey an insulating film in a manufacturing step and which can prevent a product failure from occurring. <P>SOLUTION: The method for manufacturing the chip on film carrier tape having a wiring pattern 21 made of a conductive layer 11 on a surface of a continuous insulating layer 12, a plurality of sprocket holes 22 provided at both sides in a widthwise direction of the wiring pattern 21 in such a manner that an electronic component is mounted on the wiring pattern 21 comprises a step of thermocompression bonding a reinforcing film 14 by adhering the film 14 to an opposite side to the conductive layer 11 of the insulating layer 12, a step of forming the sprocket holes 22 in regions of both sides in the widthwise direction, a step of again thermocompression bonding the reinforcing film 14 to the insulating film 12, and a step of forming the wiring pattern 21 by forming and etching a resist pattern on the conductive layer 11 and forming a dummy wiring 23 on peripheries of the plurality of sprocket holes 22. <P>COPYRIGHT: (C)2004,JPO

Description

【００５５】
以上説明したように、実施例１，２では、スプロケットホール形成後、熱圧着工程を行ったので、プロセス過程で剥離部に液が入り込むことが無く、液が残留することがなかったが、比較例１、２では、スプロケットホール形成時に補強フィルムが剥離し、剥離した部分に液の残留物が存在していた。この残留物は、テープが水切り工程や乾燥工程を経てくるので、乾燥した白色粉末状のものとして観察される。
【００５６】
また、補強フィルムは比較的熱収縮率が大きく、厚さを５０μｍから２５μｍとすると、実施例２及び比較例２，３のように、熱収縮が著しく小さくなった。しかしながら、比較例３では補強フィルムを接合強度が大きな粘着剤で接合したので、スプロケットホール形成時に剥離することがなかったが、補強フィルムを剥がす際に応力が残留して反りが発生した。
【００５７】
【発明の効果】
以上説明したように、本発明では、幅方向両側のスプロケットホール形成後、熱圧着する工程を再度行うようにしたので、製造工程において絶縁フィルムを良好に搬送でき、製品不良の発生を防止することができるＣＯＦフィルムキャリアテープの製造方法を提供することができるという効果を奏する。
【図面の簡単な説明】
【図１】本発明方法により製造したＣＯＦフィルムキャリアテープを示す概略構成図であって、（ａ）は平面図であり、（ｂ）は断面図である。
【図２】本発明方法に用いるＣＯＦ用積層フィルムの一例を示す断面図である。
【図３】本発明方法により製造したＣＯＦフィルムキャリアテープの他の例を示す概略断面図である。
【図４】本発明の一実施形態に係るＣＯＦフィルムキャリアテープの製造工程の一例を示す断面図である。
【図５】本発明の他の実施形態に係る製造方法で製造したＣＯＦフィルムキャリアテープを示す概略構成図である。
【符号の説明】
１０，１０Ａ　ＣＯＦ用積層フィルム
１１　導体層
１２　絶縁層
１３　粘着層
１４　補強フィルム
２０　ＣＯＦフィルムキャリアテープ
２１　配線パターン
２２　スプロケットホール
２３，２３Ａ　ダミー配線[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a COF film carrier tape on which electronic components such as an IC and an LSI are mounted.
[0002]
[Prior art]
With the development of the electronics industry, demand for printed wiring boards on which electronic components such as ICs (integrated circuits) and LSIs (large-scale integrated circuits) are mounted has been rapidly increasing. There is a demand for higher functionality, and as a mounting method of these electronic components, recently, a mounting method using a film carrier tape for mounting electronic components such as a TAB tape, a T-BGA tape, an ASIC tape, and a COF tape has been adopted. In particular, the importance thereof is increasing in the electronic industry using a liquid crystal display device (LCD), such as a personal computer and a mobile phone, for which high definition, thinness, and a narrow frame area of a liquid crystal screen are required. ing.
[0003]
As a method of manufacturing the electronic component mounting film carrier tape, generally, a plurality of wiring patterns and the like are formed on the insulating layer while continuously transporting a long insulating layer having sprocket holes on both sides in the width direction. Form.
[0004]
In addition, such electronic component mounting film carrier tapes have been desired to be thinner with the downsizing of electronic devices, and in recent years, those using relatively thin insulating films have been proposed. Have been.
[0005]
However, as described above, the film carrier tape for mounting electronic components, while continuously transporting the insulating layer, to form a wiring pattern and the like, if the thickness of the insulating layer is thin, the insulating film may be deformed during transport, Or there is a problem that it cuts. In addition, the strength of the sprocket hole cannot be sufficiently secured, and the sprocket hole is deformed during transportation, so that wiring patterns and solder resist patterns cannot be formed at predetermined positions with high precision, or electronic components cannot be formed with high precision. There was also a problem that it could not be implemented.
[0006]
In order to solve such a problem, Japanese Patent Application Laid-Open No. 2000-223795 discloses a method in which a reinforcing film is provided on a base film, sprocket holes are formed, dummy wires are provided, and then the reinforcing film is peeled off. Have been.
[0007]
[Problems to be solved by the invention]
However, according to the method described above, the reinforcing film is adhered to the base film via the adhesive layer. In this case, when a sprocket hole is formed, the reinforcing film is peeled off at the edge of the hole, and the subsequent peeling is performed at the peeled portion. There has been a problem that the processing solution of the chemical processing process is brought in and remains, causing problems in the process and the product.
[0008]
On the other hand, if the strength of the adhesive layer is increased to prevent peeling at the hole edge of the reinforcing film when forming sprocket holes, stress remains in the base film when the reinforcing film is peeled off after the sprocket holes are formed, There is a problem that the product is curled.
[0009]
Further, when a relatively inexpensive polyester film or the like is used as the reinforcing film, for example, the heat shrinkage and thermal deformation of the reinforcing film in the heat treatment process such as the whisker suppression process after tin plating and the curing process of the solder resist cause COF There has been a problem in that a defect due to a positioning error in manufacturing processing or a flow error due to warpage occurs.
[0010]
In view of such circumstances, an object of the present invention is to provide a method of manufacturing a COF film carrier tape that can satisfactorily convey an insulating film in a manufacturing process and can prevent occurrence of a product defect.
[0011]
Means for Solving the Invention
A first aspect of the present invention for solving the above-mentioned problems has a wiring pattern made of a conductive layer on a surface of a continuous insulating layer, and a plurality of sprocket holes provided on both sides in the width direction of the wiring pattern. In a method of manufacturing a COF film carrier tape in which electronic components are mounted on a wiring pattern, a step of attaching a reinforcing film to the insulating layer on the side opposite to the conductive layer and performing thermocompression bonding; A step of forming a sprocket hole, a step of performing thermocompression bonding between the reinforcing film and the insulating layer again, forming a resist pattern on the conductive layer and etching to form the wiring pattern, and Forming a dummy wiring around a sprocket hole. A.
[0012]
In the first aspect, since the reinforcing film is provided at the center in the width direction of the insulating layer, the problem that the insulating layer is deformed or cut during transportation in the manufacturing process can be prevented, and the sprocket hole can be prevented. It is possible to avoid the problem that the reinforcing film is peeled off at the edge of the hole during the formation and the liquid of the subsequent process is embraced and remains.
[0013]
According to a second aspect of the present invention, there is provided the COF film carrier tape according to the first aspect, wherein a bonding strength between the reinforcing film and the insulating layer after thermocompression bonding is 0.20 N / cm or less. In the manufacturing method.
[0014]
In the second aspect, since the bonding strength between the insulating layer and the reinforcing film is as small as 0.20 N / cm or less, no stress remains on the COF film carrier tape when the reinforcing film is peeled, and deformation or the like occurs. There is no.
[0015]
A third aspect of the present invention is the method for producing a COF film carrier tape according to the first or second aspect, wherein the dummy wiring is provided intermittently around each of the plurality of sprocket holes.
[0016]
In the third aspect, it is possible to avoid problems such as uneven strength when the strip-shaped dummy wiring is provided and dropping of metal powder due to friction with sprocket holes.
[0017]
A fourth aspect of the present invention is the COF film carrier tape according to any one of the first to third aspects, wherein a predetermined interval is provided between a width direction end of the insulating layer and the dummy wiring. In the manufacturing method.
[0018]
In the fourth aspect, since there is no dummy wiring up to the end in the width direction, the problem of metal powder falling due to friction with the sprocket holes is prevented.
[0019]
A fifth aspect of the present invention is the method for producing a COF film carrier tape according to any one of the first to fourth aspects, wherein the thickness of the reinforcing film is equal to or smaller than the thickness of the insulating layer. It is in.
[0020]
In the fifth aspect, since the reinforcing film thinner than the insulating layer is provided, it is possible to avoid a problem due to deformation and shrinkage of the reinforcing film.
[0021]
A sixth aspect of the present invention is the method for producing a COF film carrier tape according to the fifth aspect, wherein the thickness of the reinforcing film is 25 to 50 μm.
[0022]
In the sixth aspect, since the reinforcing film is relatively thin, even if thermal deformation or the like occurs, the COF film carrier tape itself is hardly affected.
[0023]
A seventh aspect of the present invention is the method for producing a COF film carrier tape according to any one of the first to sixth aspects, further comprising a step of peeling the reinforcing film after forming the dummy wiring. It is in.
[0024]
In the seventh aspect, even if the reinforcing film is peeled off after the formation of the dummy wiring, stable conveyance can be performed at the time of mounting electronic components or the like.
[0025]
Examples of the laminated film of the conductor layer and the insulating layer used in the COF film carrier tape of the present invention include a laminated film in which an adhesion strengthening layer such as nickel is sputtered on an insulating layer such as a polyimide film and then subjected to copper plating. Can be. Examples of the laminated film include a casting type in which a polyimide film is laminated on a copper foil by a coating method and a thermocompression-type laminated film in which an insulating layer is thermocompression-bonded to a copper foil through a thermoplastic resin or a thermosetting resin. be able to. In the present invention, any of them may be used. The conductor layer may be made of gold, silver, or the like in addition to copper, but copper foil is generally used. In addition, as the copper foil, any of an electrolytic copper foil, a rolled copper foil, and the like can be used. The thickness of the conductor layer is generally from 1 to 70 μm, and preferably from 5 to 35 μm.
[0026]
As the insulating layer, in addition to polyimide, polyester, polyamide, polyether sulfone, liquid crystal polymer, or the like can be used, and it is particularly preferable to use wholly aromatic polyimide having a biphenyl skeleton. When a polyimide film is used, the thickness is preferably about 5 to 50 μm, and more preferably about 25 to 40 μm.
[0027]
On the other hand, as a reinforcing film used in the present invention, a polyester film, a polyimide film, or the like can be used. The thickness is preferably the same as or thinner than the insulating layer, and is preferably about 25 μm, but may be about 5 μm to 50 μm.
[0028]
The method of joining the reinforcing film to the insulating layer is not particularly limited, and after applying an adhesive layer or an adhesive layer to at least one of the reinforcing film or the insulating layer, the joining may be performed, or the adhesive layer or the adhesive layer may be formed. A reinforcing film that is provided in advance may be attached. Further, after both are pasted together, they may be simply subjected to pressure bonding or the like, or may be subjected to thermocompression bonding, and are not particularly limited.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on embodiments.
[0030]
FIG. 1 shows a COF film carrier tape manufactured by the method of the present invention, and FIG. 2 shows a laminated film for COF used therein. As shown in FIG. 2, the COF film carrier tape 20 shown in FIGS. 1A and 1B has a conductor layer 11 made of a copper foil, an insulating layer 12 made of a polyimide film, and a conductor layer 11 of the insulating layer 12. Is manufactured using the laminated film for COF 10 having the reinforcing film 14 adhered to the opposite side via the adhesive layer 13. FIG. 2 shows an example of a method of manufacturing the laminated film 10 for COF by a coating method. First, a polyimide precursor or a polyimide precursor containing a varnish is formed on a conductor layer 11 made of copper foil (FIG. 2A). The resin composition is applied to form a coating layer 12a (FIG. 2B), and the solvent is dried and wound. Next, a heat treatment is performed in a cure furnace purged with oxygen, and imidization is performed to form an insulating layer 12 (FIG. 2C). Next, a reinforcing film 14 having an adhesive layer 13 is bonded to the insulating layer 12 on the side opposite to the conductor layer 11, and is bonded by thermocompression bonding (FIG. 2D) (FIG. 2E). Here, the bonding strength between the reinforcing film 14 and the insulating layer 12 is preferably set to 0.20 N / cm or less. If the bonding strength is higher than this, stress is left when the reinforcing film is peeled off, which may cause deformation of the COF film carrier tape or the like, which is not preferable.
[0031]
The COF film carrier tape 20 has a wiring pattern 21 in which the conductor layer 11 is patterned, and sprocket holes 22 provided on both sides of the wiring pattern 21 in the width direction. The wiring patterns 21 each have a size substantially corresponding to the size of the electronic component to be mounted, and are continuously provided on the surface of the insulating layer 12. In addition, a dummy wiring 23 that is electrically independent of the wiring pattern 21 is provided at a peripheral portion of the sprocket hole 22. Further, on the wiring pattern 21, there is a solder resist layer 24 formed by applying a solder resist material coating solution by a screen printing method. Note that at least a region corresponding to the inner lead 21a of the wiring pattern 21 is a plating layer that can be gold-tin eutectic bonding or gold-gold thermocompression bonding to the gold bump of the electronic component, for example, tin plating, tin alloy plating, gold plating , A gold alloy plating, or a plating layer instead of this.
[0032]
Here, the reinforcing film 14 has a function of reinforcing the central portion in the width direction of the insulating layer 12 in the process of manufacturing the COF film carrier tape 20 described above. Further, as will be described later, after the sprocket holes 22 are formed, the step of thermocompression bonding is performed again. Therefore, there is a problem that the processing liquid of the subsequent chemical processing process is brought in and remains, causing a problem in the process and the product. do not do.
[0033]
While the COF film carrier tape 20 may be left with the reinforcing film 14 remaining, as shown in FIG. 3, the COF film carrier tape 20 may be subjected to an electronic component mounting step with the reinforcing film 14 removed.
[0034]
After peeling off the reinforcing film 14, a thin portion for bending may be provided in a region corresponding to the wiring pattern 21 by laser processing or the like.
[0035]
Next, a manufacturing method according to an embodiment of the above-described COF film carrier tape will be described with reference to FIG.
[0036]
As shown in FIG. 4A, a laminated film 10 for COF is prepared, and as shown in FIG. 4B, a sprocket hole 22 is formed through the conductor layer 11 and the insulating layer 12 by punching or the like. . The sprocket holes 22 may be formed on the front surface of the insulating layer 12, or may be formed on the back surface of the insulating layer 12. Next, as shown in FIG. 4C, thermocompression bonding is performed again to completely join the reinforcing film 14 to the insulating layer 12. Thereafter, as shown in FIG. 4D, for example, a negative photoresist material coating solution is applied over the region where the wiring pattern 21 is formed on the conductor layer 11 by using a general photolithography method. Thus, a photoresist material coating layer 50 is formed. Of course, a positive photoresist material may be used. Further, after positioning the insulating layer 12 by inserting positioning pins into the sprocket holes 22, the photoresist material coating layer 50 is patterned by exposing and developing through the photomask 51, and FIG. A resist pattern 52 as shown in e) is formed. At this time, a dummy wiring pattern is also formed together with the wiring pattern. Next, using the resist pattern 52 as a mask pattern, the conductor layer 11 is dissolved and removed with an etchant, and the resist pattern 52 is further dissolved and removed with an alkaline solution or the like, thereby forming a wiring pattern as shown in FIG. 21 and dummy wirings 23 are formed. Subsequently, as shown in FIG. 4G, a solder resist layer 24 is formed in a region excluding the inner leads 21a and the outer leads 21b by using, for example, a screen printing method.
[0037]
In the above-described manufacturing process, the dummy wirings 23 are provided in a strip shape, but the present invention is not limited thereto. The dummy wirings 23 may be provided intermittently in the transport direction for each sprocket hole. This example is shown in FIG. In this case, in the COF film carrier tape 20A, the dummy wirings 23A are provided intermittently on the periphery of each sprocket hole 22.
[0038]
Although the dummy wiring is formed in the same step as the wiring pattern 21 in the above-described step, the dummy wiring may be separately provided in a separate step from the wiring pattern 21, for example, by a transfer method for partially transferring the wiring.
[0039]
In the present invention, after forming the sprocket holes on both sides in the width direction, a step of thermocompression bonding is provided again.Thus, when the reinforcing film is peeled off when forming the sprocket holes, while avoiding problems due to deformation of the film itself. Can be prevented.
[0040]
Further, when a relatively inexpensive polyester film or the like is used as the reinforcing film, for example, the heat shrinkage and thermal deformation of the reinforcing film in the heat treatment process such as the whisker suppression process after tin plating and the curing process of the solder resist cause COF There was a problem that defects due to flow abnormalities due to positioning errors and warpage in the manufacturing process occurred.However, problems such as thermal deformation were avoided by using relatively thin, for example, the same or thinner insulating film. can do.
[0041]
In addition, when the dummy wiring is provided in the manufacturing process, there is no problem in transporting the electronic component or the like even when the reinforcing film is peeled thereafter.
[0042]
Furthermore, in particular, by providing dummy wiring intermittently for each sprocket hole, the rigidity can be improved to such an extent that the insulating layer can be reliably transported, but the rigidity of the insulating layer does not become too large, and defects such as breakage and deformation are caused. Does not occur.
[0043]
Further, by providing a space between the dummy wiring and the end in the width direction of the insulating layer without providing the dummy wiring to the end, it is possible to prevent a short circuit or the like from occurring in the wiring pattern. That is, when the insulating layer is transported during manufacturing, the dummy wiring comes into contact with a guide or the like provided in the transport path to generate a metal piece, and the metal piece contacts the wiring pattern to cause a defect such as a short circuit. Can be prevented.
[0044]
In addition, since the rigidity of the entire tape does not become too large, the tape itself can freely follow the transport path even when the transport path is curved, so that the tape can be suitably transported.
[0045]
(Example 1)
An insulating layer made of Kapton-EN25 (trade name, manufactured by Dupont Toray Co., Ltd.), which is a commercially available polyimide film having a thickness of 25 μm, is provided with a sputtered adhesion reinforcing layer and a conductor layer formed of a copper plating layer provided thereon. In addition, a polyester film (Lumirror 50S10, trade name, manufactured by Toray Industries, Inc.) having a thickness of 50 μm was provided as a reinforcing film. The bonding strength at this time was 0.10 N / cm. After that, a sprocket hole was formed, and thermocompression bonding was performed again. Then, a wiring pattern and a dummy wiring were formed and a solder resist layer was provided to obtain a COF film carrier tape.
[0046]
(Example 2)
A COF film carrier tape was prepared in the same manner as in Example 1 except that the reinforcing film was a polyester film having a thickness of 25 μm (Lumirror 25S10, manufactured by Toray Industries, Inc.).
[0047]
(Comparative Example 1)
A COF film carrier tape was prepared in the same manner as in Example 1 except that the step of thermocompression bonding of the reinforcing film after the formation of the sprocket holes and the insulating film was not performed.
[0048]
(Comparative Example 2)
A COF film carrier tape was prepared in the same manner as in Example 2 except that the thermocompression bonding step with the insulating film was not performed on the reinforcing film after the formation of the sprocket holes.
[0049]
(Comparative Example 3)
A COF film carrier tape was produced in the same manner as in Comparative Example 2, except that the bonding strength when the reinforcing film was bonded to the insulating film and thermocompression bonded was set to 0.50 N / cm.
[0050]
(Test example)
In each of the examples and comparative examples, it was observed whether or not the liquid used in the process remained between the reinforcing film and the insulating layer.
[0051]
Further, the tape length after the provision of the solder resist layer was compared with the initial stage of the process to measure the tape shrinkage (%).
[0052]
Furthermore, the warpage of the film carrier tape after peeling off the reinforcing film was measured. The warpage is measured by measuring the height h (mm) from the base at both ends in the longitudinal direction when a film carrier tape having a length of 100 mm is placed on the base with the reinforcing film facing upward. And less than 5 mm was evaluated as small.
[0053]
Table 1 shows the results.
[0054]
[Table 1]

[0055]
As described above, in Examples 1 and 2, the thermocompression bonding step was performed after the formation of the sprocket holes, so that the liquid did not enter the peeling portion during the process and no liquid remained. In Examples 1 and 2, the reinforcing film was peeled off at the time of forming the sprocket holes, and a liquid residue was present at the peeled portion. This residue is observed as a dry white powder as the tape goes through a draining step and a drying step.
[0056]
The heat shrinkage of the reinforcing film was relatively large, and when the thickness was 50 μm to 25 μm, the heat shrinkage was remarkably small as in Example 2 and Comparative Examples 2 and 3. However, in Comparative Example 3, since the reinforcing film was bonded with an adhesive having a high bonding strength, the reinforcing film was not peeled off at the time of forming the sprocket hole. However, when the reinforcing film was peeled off, stress remained and warpage occurred.
[0057]
【The invention's effect】
As described above, in the present invention, after forming the sprocket holes on both sides in the width direction, the thermocompression bonding process is performed again, so that the insulating film can be transported favorably in the manufacturing process, and the occurrence of product defects can be prevented. It is possible to provide a method of manufacturing a COF film carrier tape that can perform the above-described steps.
[Brief description of the drawings]
FIG. 1 is a schematic structural view showing a COF film carrier tape manufactured by the method of the present invention, wherein (a) is a plan view and (b) is a cross-sectional view.
FIG. 2 is a sectional view showing an example of a laminated film for COF used in the method of the present invention.
FIG. 3 is a schematic sectional view showing another example of the COF film carrier tape manufactured by the method of the present invention.
FIG. 4 is a cross-sectional view illustrating an example of a manufacturing process of the COF film carrier tape according to one embodiment of the present invention.
FIG. 5 is a schematic configuration diagram showing a COF film carrier tape manufactured by a manufacturing method according to another embodiment of the present invention.
[Explanation of symbols]
10, 10A COF laminated film 11 Conductive layer 12 Insulating layer 13 Adhesive layer 14 Reinforcing film 20 COF film carrier tape 21 Wiring pattern 22 Sprocket holes 23, 23A Dummy wiring

Claims (7)

A COF film carrier tape having a wiring pattern made of a conductive layer on the surface of a continuous insulating layer, and a plurality of sprocket holes provided on both sides in the width direction of the wiring pattern, wherein electronic components are mounted on the wiring pattern In the manufacturing method of
A step of attaching a reinforcing film to the opposite side of the insulating layer from the conductive layer and thermocompression bonding; a step of forming the sprocket holes in regions on both sides in the width direction; and a thermocompression bonding of the reinforcement film and the insulating layer. Again forming a resist pattern on the conductive layer and etching to form the wiring pattern and form a dummy wiring around the plurality of sprocket holes. Of producing a COF film carrier tape. The method for producing a COF film carrier tape according to claim 1, wherein a bonding strength between the reinforcing film and the insulating layer after thermocompression bonding is 0.20 N / cm or less. 3. The method according to claim 1, wherein the dummy wiring is provided intermittently around each of the plurality of sprocket holes. 4. The method of manufacturing a COF film carrier tape according to claim 1, wherein a predetermined interval is provided between an end of the insulating layer in a width direction and the dummy wiring. The method for manufacturing a COF film carrier tape according to any one of claims 1 to 4, wherein the thickness of the reinforcing film is equal to or smaller than the thickness of the insulating layer. 6. The method according to claim 5, wherein the thickness of the reinforcing film is 25 to 50 [mu] m. 7. The method of manufacturing a COF film carrier tape according to claim 1, further comprising a step of removing the reinforcing film after forming the dummy wiring.

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