KR100575039B1 - Method for manufacturing flexible printed wiring board - Google Patents

Abstract

A manufacturing method of a flexible printed wiring board capable of improving the inspection property of a pattern defect.

A manufacturing method of a flexible printed wiring board having a step of forming two or more layers of plating layers on a conductor pattern 13 made of a conductor layer provided on a surface of an insulating layer 11 and a step of performing heat treatment in any step The conductor pattern 13 formed on the surface of the base plating layer 101 is recognized by recognizing the defects of the pattern before the base plating layer 101 is formed on the conductor pattern 13 and then the heating process is performed By performing the pattern inspecting process, the inspectability of pattern defects can be improved.

Wiring board, insulating layer, plating layer, wiring pattern, sprocket hole, photoresist material, photomask,

Description

METHOD FOR MANUFACTURING FLEXIBLE PRINTED WIRING BOARD BACKGROUND OF THE INVENTION [0001]

1 is a schematic view showing a flexible printed wiring board according to Embodiment 1 of the present invention, wherein (a) is a plan view and (b) is a cross-sectional view.

2 is a cross-sectional view for explaining an example of a manufacturing method of a flexible printed wiring board according to Embodiment 1 of the present invention.

3 is a schematic view for explaining a pattern inspection process according to Embodiment 1 of the present invention.

4 is a cross-sectional view for explaining an example of a manufacturing method of a flexible printed wiring board according to Embodiment 1 of the present invention.

Explanation of reference numerals

10 Flexible printed wiring board 11 Insulating layer

12 conductor layer 13 conductor pattern

14 Wiring pattern 15 Sprocket hole

16 solder resist layer 20 laminated film for COF

21 Photoresist material Coating layer 22 Photomask

23 Resist pattern for wiring pattern 100 Plating layer

101 base plating layer 102 main plating layer

200 automatic appearance inspection device 201 pedestal

202 concave portion 203 CCD camera

204 light source

The present invention relates to a method of manufacturing a flexible printed wiring board on which electronic components such as ICs or LSIs are mounted.

Along with the development of the electronics industry, demand for printed wiring boards for mounting electronic components such as ICs (integrated circuits) and LSIs (large-scale integrated circuits) is rapidly increasing. However, there is a demand for miniaturization, As a mounting method of these electronic components, a flexible printed wiring board (hereinafter, referred to as " flexible printed wiring board ") such as TAB (Tape Automated Bonding), T-BGA (Ball Grid Array) tape, ASIC tape, A mounting method using a mounting method is adopted. Particularly, in the electronic industry using a liquid crystal display device (LCD) in which high definition, thinness, and a small frame area of a liquid crystal screen are required, such as a mobile phone, a personal computer (PC) It is getting higher.

As a mounting method for mounting a higher density in a smaller space, a COF (Chip On Film) tape for directly mounting an IC chip on a flexible printed wiring board has been put to practical use.

Here, this flexible printed wiring board is manufactured as follows. For example, first, a sprocket hole or the like for transportation is formed on both sides in the width direction of the insulating layer made of polyimide, and a photoresist layer is formed on a copper foil provided on one side of the insulating layer while carrying the insulating layer using the sprocket holes. . Next, the photosensitive resin layer is patterned by exposure and development, the copper foil is removed by etching using the photosensitive resin layer formed into a predetermined shape by patterning, and the photosensitive resin layer is removed to form a conductor pattern. Next, after a solder resist layer is formed on the conductor pattern, a tin plating layer is formed. Alternatively, after a wiring pattern is formed by forming a tin plating layer on the conductor pattern, a solder resist layer is formed on each wiring pattern except the terminal portions such as an inner lead and an outer lead. Further, A tin plating layer is formed thereon. In the latter case, generally, a heat treatment is performed to form a solder resist layer to form a Cu-Sn alloy layer and to prevent the occurrence of a false defect.

Further, in such a flexible printed wiring board, if a defective pattern is present in a conductor pattern, a product becomes defective and becomes a serious problem. Conventionally, after a conductor pattern is formed so as not to bring a defect into a process after the formation of a conductor pattern, It is common to carry out a pattern inspecting process for inspecting defects of a conductor pattern by visual inspection of the conductor pattern or automatic appearance inspection apparatus (AOI). The AOI is designed to inspect the defect of the conductor pattern by optically reading the conductor pattern with an image reading camera and comparing it with data (reference sample) for verification confirmation (see Japanese Patent Laid-Open No. 2001-356099) .

In recent years, however, in the above-mentioned flexible printed wiring board, the wiring pitch of the conductor pattern is gradually increasing to 40 占 퐉 or less (line width of 20 占 퐉 or less) and fine pitch, and defects of the pattern are visually recognized by human eyes or identified by AOI It becomes difficult to do.

For example, after the formation of the conductor pattern, there is a portion where the surface of the copper foil is oxidized and discolored, and such a discolored portion is erroneously recognized as a defect in a pseudo-pattern, thereby lowering the yield of the product. On the other hand, after the formation of the tin plating layer, the occurrence of the foil causes a short circuit of the wiring pattern. Therefore, the heat treatment is generally performed immediately after the tin plating. In addition to this, the flexible printed wiring board is subjected to wave deformation, Wavy distortion occurs in the longitudinal direction on both sides in the tape width direction in which the holes are provided. In the case of AOI, positional shifts occur and are erroneously recognized when compared with the verification confirmation data. Such deformation of the tape is remarkable in the production of a relatively thin type flexible printed wiring board such as the COF tape described above.

That is, in the conventional pattern inspecting process, the AOI may erroneously recognize a normal conductor pattern as a defect, and the detected defective portion of the AOI must be re-inspected again by consuming time, and the inspectability of the pattern defect is poor There is a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a manufacturing method of a flexible printed wiring board capable of improving the inspection property of a pattern defect in view of such circumstances.

A first aspect of the present invention which solves the above problems is a flexible printed circuit board including a step of forming two or more layers of plating layers on a conductor pattern formed of a conductor layer provided on a surface of an insulating layer, And a pattern inspecting step of inspecting a conductor pattern formed on the surface of the base plating layer and defect of the pattern after the base plating layer is formed on the conductor pattern and before the heating treatment is performed And the like.

 In this first embodiment, it is possible to prevent the occurrence of discolored portions due to oxidation on the surface of the conductor pattern by the underlying plating layer, and to prevent the discolored portion from being erroneously recognized as a defective pseudo pattern. Therefore, the inspection of pattern defects and the yield of products can be improved. In addition, by performing the pattern inspection step before the heat treatment, the tape can be favorably positioned and conveyed without being affected by the wave form of the film carrier tape,

A second aspect of the present invention is the method of manufacturing a flexible printed wiring board according to the first aspect, wherein the base plating layer has a higher surface luminance than the conductor pattern.

 In the second embodiment, the surface brightness of the conductor pattern is increased by the underlying plating layer in the pattern inspecting step, and the image recognizable range is substantially increased.

A third aspect of the present invention is the method of manufacturing a flexible printed wiring board according to the first aspect, wherein the base plating layer is formed to a thickness of 0.01 to 0.5 m.

 In this third embodiment, a desired surface brightness can be obtained in the conductor pattern by forming a base plating layer having a predetermined thickness on the conductor pattern, and the inspection of pattern defects can be improved.

A fourth aspect of the present invention is the method of manufacturing a flexible printed wiring board according to the second aspect, wherein the base plating layer is formed to a thickness of 0.01 to 0.5 m.

 In the fourth embodiment, a base plating layer of a predetermined thickness is formed on the conductor pattern, whereby desired surface brightness can be obtained in the conductor pattern, and the inspection of pattern defects can be improved.

In a fifth aspect of the present invention, in any one of the first to fourth aspects, the pattern inspecting step is performed after the base tin plating layer is formed as the base plating layer, and then the tin plating layer is thicker And a step of performing the heat treatment after forming the plating layer is carried out on the surface of the flexible printed wiring board.

 In the fifth embodiment, the pattern inspecting process is carried out before the heating process, so that the tape can be favorably positioned and transported without being affected by the wave deformation of the film carrier tape, and the inspectability of the pattern defect and the yield Can be improved. In addition, the occurrence of a fused capacitor can be prevented, and the wiring pattern can be prevented from being short-circuited.

In a sixth aspect of the present invention, in any one of the first to fourth aspects, the pattern inspecting step is performed after the base tin plating layer is formed as the base plating layer, and then the surface of the conductor pattern excluding at least the terminal portions In the step of forming the solder resist layer which covers the solder resist layer.

 In the sixth embodiment, the pattern inspecting process is carried out before the heat treatment, so that the tape can be favorably positioned and transported without the influence of the wave deformation of the film carrier tape, and the inspectability of the pattern defect and the yield Can be improved.

In a seventh aspect of the present invention, in any one of the first to fourth aspects, the pattern inspection step is performed after the nickel plating layer is formed as the base plating layer, and then the surface excluding at least the terminal portion of the conductor pattern And the step of performing the heat treatment is carried out when forming the solder resist layer to be coated.

 In the seventh aspect, by performing the pattern inspecting process before the heat treatment, the tape can be favorably positioned and conveyed without being affected by the wave deformation of the film carrier tape, and the inspectability of the pattern defect and the yield , ≪ / RTI >

Hereinafter, the present invention will be described in detail based on embodiments.

(Embodiment 1)

1 is a schematic view showing a flexible printed wiring board according to a first embodiment of the present invention, wherein (a) is a plan view and (b) is a cross-sectional view.

As shown in the figure, the flexible printed wiring board 10 of the present embodiment is a COF film carrier tape, and is formed by patterning a conductive layer 12 provided on one side of a tape-shaped insulating layer 11 13 and a plurality of sprocket holes 15 provided on both sides of the wiring pattern 14 in the width direction.

Here, as the material of the insulating layer 11, for example, polyesters, polyamides, polyether sulfone, liquid crystal polymers and the like can be used in addition to polyimide. Particularly, it is possible to use a mixture of pyromellitic acid dianhydride and aromatic diamine It is preferable to use a wholly aromatic polyimide. The thickness of the insulating layer 11 is generally 12.5 to 125 占 퐉, preferably 12.5 to 75 占 퐉, and more preferably 25 to 50 占 퐉.

On the other hand, as the material of the conductor layer 12, other than copper, for example, aluminum, gold, silver or the like may be used, but copper is common. As the copper layer, copper layer formed by vapor deposition or plating, electrolytic copper foil, rolled copper foil, or the like can be used. The thickness of the conductor layer 12 is generally 1 to 70 占 퐉, preferably 5 to 35 占 퐉.

The wiring pattern 14 is continuously provided on the surface of the insulating layer 11. The wiring pattern 14 includes a conductor pattern 13 formed by patterning a conductor layer 12 provided on the surface of the insulating layer 11 and two or more layers formed on the conductor pattern 13 And a plating layer (100). For example, in the present embodiment, the plating layer 100 is formed by laminating the base plating layer 101 and the main plating layer 102 on the entire surface on the conductor pattern 13. [ The thickness of the plating layer 100 is, for example, 0.3 to 1.0 占 퐉, and preferably 0.4 to 0.7 占 퐉.

On the wiring pattern 14 having the plating layer 100 as described above, the solder resist material coating solution is applied only to the area required by the screen printing technique, and then the solder resist layer 16 is formed by heating and curing. Of course, the solder resist layer may be formed by photolithography.

A portion of the wiring pattern 14 which is not covered with the solder resist layer 16 becomes a connection terminal portion. That is, the end of the central portion of the wiring pattern 14 becomes the inner lead 14a, and the outer end of the solder resist layer 16 on the side opposite to the inner lead 14a becomes the outer lead 14b.

Here, an example of a method of manufacturing a COF film carrier tape which is an example of the above-described flexible printed wiring board 10 will be described with reference to Figs. 2 to 4. Fig. 2 and 4 are sectional views showing an example of a method for producing a COF film carrier tape, and Fig. 3 is a schematic view for explaining a pattern inspection process.

First, as shown in Fig. 2 (a), a laminated film 20 for COF in which a conductor layer 12 is formed on an insulating layer 11 is prepared. Here, the COF-use laminated film 20 is obtained by applying a polyimide precursor resin composition containing a polyimide precursor or varnish, for example, onto a conductor layer 12 made of a copper foil to form a coating layer, Followed by drying and winding, followed by heat treatment in a curing furnace, and imidization to form an insulating layer 11. However, the present invention is not limited thereto.

Next, as shown in Fig. 2 (b), the sprocket holes 15 are formed by penetrating the insulating layer 11 and the conductor layer 12 by punching or the like. The sprocket holes 15 may be formed from the surface of the insulating layer 11 or from the back surface of the insulating layer 11,

Next, as shown in Fig. 2 (c), a photoresist material coating solution is applied over a region where the conductor pattern 13 is formed on the conductor layer 12 by using a general photolithography method, Thereby forming a material coated layer 21. A positioning pin (not shown) is inserted into the sprocket hole 15 to position the insulating layer 11 and then exposed using a photomask 22. Thereafter, the photoresist material is applied The resist pattern 23 for a conductor pattern as shown in Fig. 2 (d) is formed by patterning the layer 21,

Next, the conductor pattern 12 is dissolved and removed as an etching solution by using the resist pattern 23 for a conductor pattern as a mask pattern, and the resist pattern 23 for a conductor pattern is dissolved and removed with an alkali solution, thereby forming a conductor pattern 13 as shown in Fig.

This is the manufacturing process for forming the conductor pattern 13. Next, in this embodiment, after the base plating layer 101 is formed on the conductor pattern 13, the pattern inspection step is performed.

Specifically, first, as shown in Fig. 2 (f), on the surface of the conductor pattern 13, the surface brightness is higher than that of the conductor pattern 13, and the bonding with the electronic parts and the like in the subsequent step And the underlying plating layer 101 made of a metal less likely to cause discoloration due to oxidation than the conductor pattern 13 is formed.

It is preferable that the base plating layer 101 has a thickness of 0.01 to 0.5 mu m. As the base plating layer 101, for example, in this embodiment, a base tin plating layer is formed by electroless plating or the like. As described above, in the case of performing tin plating with a foaming problem, it is necessary to perform a heat treatment in order to prevent foaming. In the present embodiment, the degree of foaming does not occur in a short period of time, Of the surface tin plating layer to increase the surface luminance. Therefore, it is not necessary to perform the heat treatment, and the film carrier tape is not deformed. Therefore, there is no adverse effect on the pattern inspection process to be described later. As described above, since the base plating layer 101 is formed on the conductor pattern 13 and its surface luminance can be increased by about 10% to about 50% as compared with the surface of the conductor pattern 13, The inspection of pattern defects can be improved.

In addition, in the present embodiment, it is possible to reliably prevent erroneous recognition of a discolored portion due to oxidation as a pseudo-pattern defect in the pattern inspecting step. This is because, before the pattern inspecting process, the whole of the conductor pattern 13 is substantially covered with the base plating layer 101 which is thick enough not to require heat treatment and which is less prone to discoloration due to oxidation than the conductor pattern 13 It is because.

 The base plating layer 101 also serves to protect the surface of the conductor pattern 13. That is, the base plating layer 101 prevents the surface of the conductor pattern 13 from being oxidized. Therefore, it is preferable that the base plating layer 101 is formed immediately after the conductor pattern 13 is formed. This is because, when the oxidized discolored portion exists on the surface of the conductor pattern 13, there is a possibility that the inspection property in the pattern inspection step described later is adversely affected.

Next, in the previous step, a pattern inspection process for inspecting the defects of the pattern by recognizing the conductor pattern 13 on which the base plating layer 101 is formed on the surface is performed. For example, in the present embodiment, as shown in Fig. 3A, it is possible to irradiate light from the side of the conductor pattern 13 of the insulating layer 11 and to recognize the reflected light to inspect the defects of the pattern A pattern inspection process was performed using the automatic appearance inspection apparatus 200 as much as possible.

Specifically, in the automatic visual inspection apparatus 200, the film carrier tape to be inspected is first conveyed by a conveyance gear (not shown), and tensioned with a predetermined tension toward the upstream side and the downstream side in the conveyance direction , And is fixed to the concave portion 202 of the pedestal 201 in this state (see Fig. 3 (a)). Alternatively, although not shown, there is also a method of temporarily pressing the tape against the pedestal with a rubber roller from the upper side of the tape on the upstream side and the downstream side. Next, the whole of the conductor pattern 13 is irradiated by the light source 204 disposed above the tape, that is, on the conductor pattern 13 side so as to surround the CCD (Charge Coupled Device) camera 203. Subsequently, each of the conductor patterns 13 provided on the surface of the base plating layer 101 described above is optically read by the CCD camera 203 disposed on the side of the conductor pattern 13 such as the light source 204. Then, a pattern defect such as disconnection is inspected by superimposing, for example, a reference sample (verification confirmation data) by an image processing unit (not shown) and verifying the verification. Actually, in the case where a defect of the conductor pattern 13 is detected, it is preferable that the operator confirms whether or not the normal conductor pattern 13 is detected as a pattern defect with respect to the displayed defect information (verification) to be.

Here, when the pattern defect is inspected by the automatic visual inspection apparatus 200 as described above, in the present embodiment, the base plating layer 101 is formed on the surface of the conductor pattern 13, Is about 10 to 50% higher than that of the surface of the conductive pattern 13, the shape of the whole conductor pattern 13 can be actually read.

More specifically, when the conductor layer 12 is etched to form the conductor pattern 13, the cross-sectional shape of each conductor of the conductor pattern 13 is generally trapezoidal as shown in Fig. 3 (b). In the configuration of only the conductor pattern 13, the line width of each wiring of the conductor pattern 13 is recognized as the width of the top surface A because it does not have a sufficient surface luminance. 3C, by forming the base plating layer 101 on the conductor pattern 13, the surface luminance is higher than that of the conductor pattern 13, The line widths of the respective wirings are recognized on the whole surface (B). That is, the range (surface area) in which the image is recognized is substantially increased, and the shape of the entire wiring pattern 14 can be largely read. This makes it possible to improve the inspection performance of pattern defects and the yield of products.

Further, in the present embodiment, since the range of recognizing the image can be enlarged, the permissible range (area) becomes large when the image pattern of the conductor pattern 13 recognized with the image and the reference sample are superimposed on each other, It is possible to improve the property.

 Since the formation of the discolored portion due to oxidation can be prevented by forming the base plating layer 101 on the surface of the conductor pattern 13, the discolored portion due to oxidation is erroneously recognized as a pseudo-pattern defect Can be reliably prevented. Therefore, it is possible to significantly reduce burden of confirmation work of verification by the operator.

After the pattern inspecting process is performed as described above, the main plating layer 102 is formed on the base plating layer 101 in this embodiment, as shown in Fig. 4 (a). For example, in the present embodiment, a main tin plating layer thicker than the base plating layer 101 is formed as the main plating layer 102 by electroless plating or the like. The thickness of the main plating layer 102 is preferably 0.3 to 0.7 mu m, for example. This is for ensuring the thickness necessary for electrical connection with the outside at each terminal portion of the inner lead 14a and the outer lead 14b. Thereafter, a heating (curing) treatment is performed at about 100 to 200 DEG C to prevent foaming, thereby forming a plating layer 100 composed of a base plating layer 101 and a main plating layer 102 ) Reference). As a result, at least the boundary portion between the base plating layer 101 and the conductor pattern 13 of the plating layer 100 becomes an alloy plating layer.

Next, as shown in Fig. 4 (b), a solder resist material coating liquid is coated on the wiring pattern 14 (actually, the plating layer) by, for example, a screen printing method, The solder resist layer 16 is formed to complete the flexible printed wiring board 10 as shown in Fig.

As described above, in the present embodiment, occurrence of fogging can be prevented by forming the main plating layer 102 on the base plating layer 101, applying the solder resist material coating liquid, and performing the heat treatment, 14 can be prevented from being short-circuited.

In this embodiment, since the heating process is performed after the pattern inspecting process, the film carrier tape is not deformed in the pattern inspection process. That is, in the pattern inspecting process, the film carrier tape can be properly positioned and transported. Therefore, misalignment can be prevented from occurring due to positional deviation when checking the reference sample against the reference sample. Therefore, the inspection of pattern defects and the yield of products can be improved.

In the present embodiment, the heat treatment is performed in the step of forming the solder resist layer 16, but of course, the heat treatment may be performed before applying the solder resist material coating liquid. Even in this case, since the heat treatment is performed after the pattern inspecting step, the tape can be favorably positioned and transported without affecting the pattern inspecting step, so that the inspection performance of the pattern defect and the yield of the product can be improved .

As described above, in this embodiment, after the base plating layer 101 having a surface luminance higher than that of the conductor pattern 13 is formed on the conductor pattern 13, the base plating layer 101 It is possible to increase the surface brightness of the conductor pattern 13 by the underlying plating layer 101 in the pattern inspecting step because the pattern inspection step of inspecting the conductor pattern 13 formed on the surface and inspecting the defects of the pattern is performed. And the inspection of pattern defects can be improved. For example, in the configuration in which the pitch of the conductor pattern 13 is 40 占 퐉 or less (line width is 20 占 퐉 or less), that is, only the conductor pattern 13 obtained by making the pitch of the conductor pattern 13 satisfies a sufficient surface luminance, However, in the manufacturing method of the present embodiment, since the pattern inspecting step is performed after the base plating layer 101 is provided on the surface of such a conductive pattern 13, a sufficient surface brightness is obtained at the time of inspection , It is particularly effective in that the degree of image recognition can be increased,

In the present embodiment, in the case of performing tin plating with a Huiska problem, a base tin plating layer of such a degree as not causing hysteresis is used as a base plating layer, a pattern inspection process is performed at this tin, The main tin plating layer is thickly formed and the heat treatment is performed immediately thereafter to improve the inspection property of the pattern inspecting process and to reliably prevent the fischer.

In addition, since the above-described flexible printed wiring board 10 is a type of COF film carrier tape having a relatively thin tape thickness, deformation of the wavy pattern due to heat treatment is likely to occur. However, in the present embodiment, since the pattern inspecting step is performed before the heating process as described above, there is no positional deviation when compared with the reference sample, and pattern inspection can be carried out reliably.

Hereinafter, the present invention will be described in more detail based on Example 1 and Comparative Examples 1 and 2.

(Example 1)

A laminate film for COF having a conductor layer having a thickness of 8 mu m formed on an insulating layer (trade name: Esfaflex; made by Sumitomo Chemical Co., Ltd.) having a thickness of 38 mu m was prepared. First, a base tin plating layer having a thickness of 0.05 mu m was formed on the conductor pattern formed by etching the conductor layer. As a result, the surface luminance of the base tin plating layer can be increased by about 35% as compared with the surface of the conductor pattern. Next, a pattern inspecting step is performed, and then a solder resist material coating liquid is applied to form a coating layer for solder resist, and curing is performed. Next, a main tin plating layer having a thickness of 0.45 占 퐉 is formed on the uncoated surface of the solder resist material coating liquid, and a manufacturing method of heating treatment at 125 占 폚 is described as Example 1 to prevent foaming.

(Example 2)

A base tin plating layer having a thickness of 0.05 탆 was formed on the conductor pattern in the same manner as in Example 1 and then subjected to a pattern inspecting step and then a main tin plating layer having a thickness of 0.45 탆 was formed on the base tin plating layer after the inspection, A manufacturing method in which a solder resist material coating layer is formed and heat treatment is performed at 125 占 폚 in order to prevent foaming, is referred to as Example 2.

(Comparative Example 1)

The same manufacturing method as in Example 1 was referred to as Comparative Example 1, except that after the conductor pattern formation, the pattern inspecting step was performed without forming the base tin plating layer, and thereafter a tin plating layer having a thickness of 0.5 占 퐉 was formed.

(Comparative Example 2)

The same manufacturing method as in Example 1 was referred to as Comparative Example 2, except that a tin plating layer having a thickness of 0.5 mu m was formed after formation of a conductor pattern, heat treatment was performed at 125 DEG C, and then pattern inspection was performed.

(Test Example 1)

The pattern inspection of the film carrier tapes obtained by the manufacturing methods of Examples 1 and 2 and Comparative Examples 1 and 2 was carried out by using the automatic appearance inspection apparatus (AOI) described above. The number of detected defective parts of the conductor pattern as pseudo-pattern defects and the number of detected defective parts due to the positional deviation at the time of checking the reference sample against the deformation of the tape due to the deformation of the tape, Including the number of bad candidates.

In addition, with respect to the tape inspected with the AOI, the visual inspection by the naked eye of a human being was performed in a time-consuming and deliberate manner, and the defective number of the conductor pattern obtained as the inspection result was called a true defective number.

As a result, in Examples 1 and 2, the number of defective candidates was 1/4 as compared with that in Comparative Example 1, and the number of defective candidates was 1/6 as compared with Comparative Example 2.

That is, in Comparative Example 1, in the pattern inspecting step, the surface of the conductor pattern was oxidized to generate a discolored portion, and this discolored portion was detected as a pseudo-pattern defect. In Examples 1 and 2, The formation of the discolored portion is suppressed by forming the plating layer, and the number of defective candidates can be reduced.

On the other hand, in Comparative Example 2, in the pattern inspecting step, the film carrier tape was deformed in wave form due to the heat treatment, so that the positional deviation from the reference sample occurred and it was detected many times as a pattern defect. And 2, since the heat treatment was performed at the time of forming the main plating layer after the pattern inspection step, it is considered that the number of defective candidates could be reduced.

From the above-described results, it is found that, as in Examples 1 and 2, the pattern inspection process is carried out after the foundation plating layer is formed on the conductor pattern and before the heat treatment, whereby the number of defective candidates close to the true defective number Can be detected. Therefore, according to the manufacturing methods of Embodiments 1 and 2, it is obvious that the inspection of pattern defects can be improved and the burden of verification work by the operator can be greatly reduced.

(Other Embodiments)

As described above, an embodiment of the present invention has been described. Of course, the manufacturing method of the flexible printed wiring board is not limited to the above.

For example, in Embodiment 1 described above, the tin plating layer is formed as the plating layer 100, but the present invention is not limited thereto. For example, a nickel-gold two-layer structure may be used as the plating layer. In this case, after a nickel plating layer is formed, a pattern inspecting step is performed, and thereafter, a solder resist layer is formed, and a gold plating layer is formed on the nickel plating layer of the terminal portion not covered with the solder resist layer. As described above, since the pattern inspecting step precedes the step of forming the solder resist layer requiring heat treatment, the inspectability of the pattern defect and the yield of the product can be improved without affecting the inspection. Further, the base tin plating layer described above may be further formed as a lower layer of such a nickel plating layer. In this case, when the pattern inspecting step is performed after the base tin plating layer is formed and then the nickel plating layer or the solder resist layer is formed, the same effects as those described above can be obtained. Of course, the pattern inspecting step may be performed after the nickel plating layer is formed. Further, the nickel plating layer has a surface luminance higher than that of the surface of the conductor pattern similarly to the tin plating layer described above, and is not easily discolored even when oxidized.

In the first embodiment described above, the flexible printed wiring board 10 in which the wiring pattern 14 is provided with one row of the carrier pattern formed of the sprocket holes 15 or the like is described and explained. However, the present invention is not limited to this example, A flexible printed wiring board in which a plurality of carrier patterns are arranged in parallel may be used.

In the COF film carrier tape according to the first embodiment described above, nothing is provided around the sprocket holes 15, but a metal layer may be provided around the sprocket holes. This metal layer may be provided continuously or intermittently in the direction in which the sprocket holes are arranged in parallel, and is not particularly limited. Further, by providing such a metal layer, even a comparatively thin type of COF tape can exhibit the effect of securing a desired tape conveyance strength.

 However, the flexible printed wiring board 10 may be a flexible printed wiring board other than the flexible printed wiring board such as TAB, CSP, BGA, μ-BGA, FC, QFP type, A double-sided wiring tape, a tape for a multilayer wiring board, an FPC, or the like, and the configuration and the like are not limited either.

Here, in the above-described Embodiment 1, a COF film carrier tape manufactured using a relatively thin conductor layer is exemplified. However, for example, a COF film carrier tape manufactured using a relatively thick conductor layer, In the case of a film carrier tape such as TAB, which is a three-layer tape having an adhesive layer, the line width of each wiring of the conductor pattern is set such that the difference in linewidth between the top surface and the bottom surface (see Figs. 3B and 3C) Therefore, by forming the base plating layer on such a conductor pattern, the range of image recognition is further increased. This makes it possible to further improve the inspection of pattern defects. In addition, when checking and checking the conductor pattern superimposed on the conductor pattern obtained by image recognition, the allowable range is further increased, and workability at the time of inspection can be further improved.

As described above, according to the present invention, before the step of forming the base plating layer on the conductor pattern and further performing the heat treatment, a pattern inspection process for inspecting defects of the pattern by recognizing the conductor pattern formed on the surface of the base plating layer is performed It is possible to prevent the occurrence of a discolored portion due to oxidation on the surface of the conductor pattern by the underlying plating layer and to prevent the discolored portion from being erroneously recognized as a defective pseudo pattern. Therefore, the inspection of pattern defects and the yield of products can be improved. Further, by performing the pattern inspection process before the heat treatment, the tape can be favorably positioned and transported without being affected by the deformation of the film carrier tape.

Claims (7)

A step of forming two or more layers of plating layers on a conductor pattern made of a conductor layer provided on a surface of an insulating layer and a step of performing heat treatment in any step, And a pattern inspecting step of inspecting defects of the pattern by recognizing the conductor pattern formed on the surface of the base plating layer after the base plating layer is formed on the conductor pattern and before the heating processing, ≪ / RTI > The manufacturing method of a flexible printed wiring board according to claim 1, wherein the base plating layer has a higher surface luminance than the conductor pattern. The manufacturing method of a flexible printed wiring board according to claim 1, wherein the base plating layer is formed to a thickness of 0.01 to 0.5 mu m. The manufacturing method of a flexible printed wiring board according to claim 2, wherein the base plating layer has a thickness of 0.01 to 0.5 占 퐉. The method according to any one of claims 1 to 4, wherein after the base tin plating layer is formed as the base plating layer, the pattern inspection step is performed, and thereafter, a thicker tin plating layer is formed on the base tin plating layer, Wherein the step of forming the flexible printed wiring board is carried out. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the pattern inspecting step is performed after forming the base tin plating layer as the base plating layer, and thereafter a solder resist layer for covering the surface of the conductor pattern, Wherein the step of performing the heat treatment is performed at the time of formation of the flexible printed wiring board. The method according to any one of claims 1 to 4, wherein the pattern inspection step is performed after the nickel plating layer is formed as the base plating layer, and then a solder resist layer is formed to cover the surface of the conductor pattern excluding at least the terminal portions Wherein the step of performing the heat treatment is performed at the time of forming the flexible printed wiring board.

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