JP3780779B2 - TAB tape manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a double-sided wiring TAB (Tape Automated Bonding) tape, and more particularly to a method for manufacturing a TAB tape with accurate alignment of exposure when forming a wiring pattern corresponding to both sides and good workability.
[0002]
[Prior art]
A general structure of the double-sided wiring TAB tape will be described with reference to FIG. 5 of the present invention.
[0003]
In FIG. 5, the double-sided wiring TAB tape 10 forms wiring patterns 5 and 7 on copper foils bonded to both sides of the insulating film 1, respectively, and the other side of the wiring pattern 7 from, for example, a solder ball pad 7a A blind via 4 extending to the inner surface of, for example, the land 5a of the wiring pattern 5 on the side is provided, and a part of both wiring patterns is electrically connected to each other, and on the wiring pattern 7 on the side where the blind via 4 is provided. A solder resist 8 is provided as a surface protective coat layer in a predetermined region.
[0004]
In producing this double-sided wiring TAB tape, conventionally, an exposure machine shown in FIG. 7 is generally used as an exposure means for the double-sided wiring TAB tape. In this exposure machine, the TAB tape 10 is wound around sprockets 18, 18 arranged at intervals through a perforation hole 11 serving as a feed hole of the TAB tape 10, and pressed by the sprocket rotation gear 20, while being driven by the driving force of the motor 21. And a mechanism for intermittent feeding. The TAB tape 10 is stably supported in a flat state by the suction disk 19 between the sprockets 18 and 18, and is irradiated by the illumination device 17 from above.
[0005]
In general, a conventional double-sided TAB tape exposure method generally includes positioning a TAB tape 10 with reference to a perforation hole 11 serving as a feed hole, exposing and developing one side of the TAB tape 10, and etching a copper foil on one side. A wiring pattern is formed. Thereafter, a photoresist was coated on another side, precured, exposed again with the perforation hole 11 and developed, and the copper foil on the other side was etched to form a copper wiring pattern.
[0006]
[Problems to be solved by the invention]
However, in general, when the TAB tape of the two-layer wiring is generated with a gap of ± 20 μm between the upper and lower wiring patterns, particularly when the wiring pitch is 80 μm or less, the diameter of the hole of the blind via 4 and the land 5a are electrically connected. Detachment failure. Further, in many cases, a photosensitive solder resist 8 is applied to the solder ball pad 7a side where the blind via 4 is present, pre-cured, and then exposed again and developed. The production rate of TAB tape for wiring deteriorates and products cannot be made efficiently.
[0007]
The conventional problem described above is because the aligning method of the exposure apparatus is not appropriate (alignment at the feed hole). For this reason, a positional shift between the upper and lower wiring patterns is generated. Particularly, when the wiring pitch is 80 μm or less, the hole of the electrically connected via (Via) and the land diameter are deviated from each other.
[0008]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a TAB tape that solves the above-described problems and has an accurate alignment of exposure positions of wiring patterns corresponding to both surfaces of a double-sided wiring TAB tape and good workability.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured as follows.
[0010]
(1) According to the invention described in claim 1, a wiring pattern is formed on each of the copper foils bonded to both surfaces of the insulating film, and a blind via extending from the wiring pattern on one side to the inner surface of the wiring pattern on the other side is formed. In a method of manufacturing a TAB tape in which a part of both wiring patterns is connected and a solder resist is provided in a predetermined region on the wiring pattern on the side where the blind via is provided, one side of the copper foil is exposed. -Set in the exposure machine so that the wiring pattern formed by etching is on the lower surface side, read the alignment position of the wiring pattern on the lower surface side with an optical sensor, and the read position matches the predetermined target position The tape is positioned, and pattern exposure is performed on the copper foil on the upper surface which is pre-baked by coating with a photoresist.
[0011]
(2) The invention described in claim 2 is the method for manufacturing the TAB tape according to claim 1, wherein the pattern exposure is a pattern for forming a wiring pattern on the copper foil on the side where the blind via is provided. It is exposure.
[0012]
(3) The invention according to claim 3 is the TAB tape manufacturing method according to claim 1 or 2, wherein the pattern exposure is performed on a predetermined area on the wiring pattern for the copper foil on the side where the blind via is provided. It is the pattern exposure with respect to the solder resist provided in this.
[0013]
(4) The invention according to claim 4 is the TAB tape manufacturing method according to claim 1, wherein the pattern exposure is a pattern for forming a wiring pattern on the copper foil on the side where the blind via is not provided. It is exposure.
[0014]
Gist of the present invention is to solve the conventional problems, when exposing the wiring pattern for the lower surface of the upper surface of the copper foil after the wiring pattern formation for the copper foil as the wiring pattern for the lower surface of the copper foil It is reading and positioning with an optical sensor. Since the double-sided wiring pattern is aligned based on the reading result, the alignment accuracy is improved as compared with the method using the feed hole as a reference, thereby improving the yield rate and improving the productivity.
[0015]
As a tape to which the present invention can be applied, a wiring pattern is formed using a two-layer CCL (Copper Clad Laminate) of an adhesive-less double-sided copper foil polyimide tape, or a double-sided copper-bonded polyimide tape using an adhesive or a single-sided wiring adhesive. There TAB (tape Automated Bonding) tape is made Te, the present invention is, in these TAB tape, any one side of the exposure of the copper etching to form the wiring pattern (or via (via)) to the made to the lower surface It is characterized in that it is set in an exposure machine, the wiring pattern (or via) on the lower surface thereof is read and positioned by an optical sensor, and pattern exposure is performed on the copper foil on the upper surface which has been coated and prebaked with a photoresist in advance.
[0016]
An effective adhesive-free double-sided copper-bonded polyimide tape has a constitutional thickness of 9 to 35 μm / 25 to 125 μm / 9 to 35 μm in copper foil / polyimide tape / copper foil. This is because these are commercially available material configurations of adhesiveless double-sided copper-clad polyimide tapes.
[0017]
Because it is a reading method with an optical sensor, it is possible to read the wiring pattern 20 μm on the lower surface (10 μm wiring width and space 10 μm) with an accuracy of ± 2 μm and keep the positional accuracy of the wiring pattern on the upper surface within ± 5 μm. It is.
[0018]
In short, in the present invention, the adhesiveless double-sided copper-bonded polyimide tape has a constitutional thickness of 9 to 25 μm / 25 to 100 μm / 9 to 25 μm, and the wiring lead pitch is 100. ~ 20μm, wiring pattern 20μm is read with a sensor, positioning is performed, photoresist is coated and pre-baked in advance, the pattern wiring lead pitch on the upper surface is 100-20μm, and the positional deviation accuracy with the lower surface pattern is within ± 5μm It can be set as the form exposed by.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with a focus on the illustrated examples.
[0020]
FIG. 1 shows an exposure machine used in this embodiment. This is basically the same as the conventional exposure apparatus already described with reference to FIG. 8, and the TAB tape 10 is wound around the sprockets 18 and 18 arranged at intervals through the perforation holes 11 serving as feed holes of the TAB tape 10. It has a mechanism that intermittently feeds by the driving force of the motor 21 while being pressed by the sprocket rotating gear 20. The TAB tape 10 is stably supported in a flat state by the suction disk 19 between the sprockets 18 and 18, and is irradiated by the illumination device 17 from above.
[0021]
However, unlike a conventional exposure machine, an optical sensor 16 for reading the pattern of the TAB tape 10 is provided below the tape running surface.
[0022]
Next, a method for manufacturing a TAB tape using the above exposure machine will be described with reference to FIGS.
[0023]
First, an adhesive-less double-sided copper-clad polyimide casting material in which electrolytic copper foils 2 and 3 are adhered to both sides of the polyimide resin insulating film 1 without an adhesive is prepared (FIG. 2A). Here, a tape having a width of 70 mm and having a copper foil thickness of 18 μm / polyimide thickness of 25 μm / copper foil thickness of 18 μm / perforation hole 11 (see FIG. 1) and the like is punched by punching.
[0024]
Thereafter, 180 holes (blind vias) 4 having a diameter of 100 μm are formed by CO ₂ laser light from one side (copper foil 2 side) (FIG. 2B).
[0025]
Next, a pattern of 60 μm wiring pitch is formed by photo application on the electrolytic copper foil (thickness 18 μm) 3 on the opposite pattern surface, and then etched to form a wiring pattern 5 by copper wiring on the copper foil 3. Create (FIG. 2C). What is formed as the wiring pattern 5 includes an inner lead (not shown) having a wiring pitch of 60 μm, as well as lands 5 a corresponding to the mounting locations of the solder balls 12 and routing wirings 5 b (see FIG. 6). included.
[0026]
Next, a photoresist 6 having a predetermined thickness is applied and prebaked on the copper foil 2 in which the blind vias 4 are opened on the surface opposite to the pattern surface (FIG. 2D).
[0027]
Thereafter, the alignment position of the wiring pattern 5 on the lower surface, here, the position of the land 5a is read by the optical sensor 16 for reading in the exposure apparatus of the present invention shown in FIG. 1 (FIG. 2 (e)). Then, according to the read position, that is, according to the deviation obtained by comparing the read current position with the target position, the sprocket 18 in FIG. 1 is driven, and the tape is moved in the direction of arrow F in FIG. By moving back and forth, the photoresist 6 on the upper surface and thus the pattern to be formed on the copper foil 2 are positioned.
[0028]
Thereafter, the photoresist 6 is exposed by an illumination device 17, developed, and post-baked (FIG. 3 (f)). Then, the wiring pattern 7 was formed in the copper foil 2 by etching using this photoresist 6 as a mask (FIG. 3G). The wiring pattern 7 includes a solder ball pad 7a.
[0029]
Next, a photosensitive photo solder resist 8 is applied to the pattern surface on the copper foil 2 side where the blind via 4 is opened, so that the copper foil 2 is covered with a photoresist pattern surface having a predetermined thickness and prebaked ( FIG. 3 (h)). Thereafter, in the same manner as in the process of FIG. 2 (e), the optical sensor 16 of the exposure machine of the present invention reads the alignment position of the wiring pattern 5 with the 60 μm wiring pitch on the lower surface, and the tape is applied according to the read position. By moving back and forth in the direction of the arrow F in FIG. 2 (i), the pattern to be formed on the photosensitive photo solder resist 8 on the upper surface is positioned (FIG. 3 (i)). Then, the pattern is exposed to the correctly positioned upper surface of the photosensitive photo solder resist 8, and then developed and post-baked, so that the solder ball pad 7 a is exposed on the photosensitive photo solder resist 8. A pattern of the non-resist region 8a was formed (FIG. 3 (j)).
[0030]
Next, electroless Sn plating 9 was applied to a region exposed from the solder resist 8 to a thickness of 0.4 μm to obtain a finished product (FIG. 4 (k)).
[0031]
By this Sn plating 9, the solder ball pads 7 a of the wiring pattern 7 on one side of the insulating film 1 and the lands 5 a of the wiring pattern 5 on the other side are conducted through the blind via 4. On the other hand, the solder balls 12 are mounted on the solder ball pads 7a as suggested in FIG. 4 (k). Therefore, when the land 5a of the wiring pattern 5 is provided as a ground layer, this ground layer can be grounded through the blind via 4 and the solder ball 12, thereby improving the high frequency characteristics of the semiconductor device. it can.
[0032]
In the pattern formation by the conventional exposure machine, the blind via 4, the solder ball pad 7a, and the land 5a are often shifted from each other as shown as the deviation 14 in FIG. 6B. In the obtained TAB tape, as shown in FIG. 6 (a), the solder ball pad 7a on one side and the resist-free region 8a are accurately aligned substantially concentrically with the land 5a on the other side. Can be formed.
[0033]
In the case of the above-described embodiment, the wiring displacement 14 between both surfaces of the finished product of the TAB tape is reduced to 1/3 or less in this manufacturing method as compared with the positional displacement amount of the wiring by pattern formation by the conventional exposure machine. confirmed. In particular, it has been found that this is very effective for the positional deviation of the second photosensitive solder resist.
[0034]
In particular, as for the deviation between the via diameter and the land diameter of the photosensitive solder resist, the conventional 70 μm deviation can be reduced to 1/5 or less, and a tape carrier for a two-layer wiring TAB with a stable positional deviation is supplied. I was able to. As a result, yield and productivity were improved, and stable mass production became possible.
[0035]
The TAB tape obtained by the present invention has high insulation resistance and excellent migration resistance.
[0036]
In the above embodiment, the case where there is no device hole has been described. However, the present invention can also be applied to the manufacture of an inner lead bonding type two-layer wiring TAB tape having a device hole.
[0037]
The two-layer wiring TAB tape obtained by the above manufacturing method has high insulation resistance and excellent migration resistance, and is used for flip chip connection without a device hole of fine wiring (pitch 50 μm or less) and It can be used for a beam lead type CSP (Chip Scale Package) with a device hole and Tape-BGA. That is, according to the TAB tape manufacturing method using the exposure machine of the present invention, in the manufacture of Tape-BGA or CSP TAB tape, the transfer, the bonding of the semiconductor chip, and the alignment of the solder balls are facilitated. Improves the product assembly rate.
[0039]
【The invention's effect】
As described above, according to the present invention, the following excellent effects can be obtained.
[0040]
(1) According to the first to fourth aspects of the present invention, the wiring pattern formed by exposing and etching one surface is set on the exposure machine so that the wiring pattern on the lower surface side is aligned. Since the tape is positioned so that the position read by the optical sensor matches the predetermined target position, and pattern exposure is performed on the top surface that has been pre-baked by coating with photoresist, both sides of the finished product of the TAB tape The wiring misalignment can be reduced to 1/3 or less compared to the positional misalignment of the wiring due to pattern formation by a conventional exposure machine.
[0041]
In particular, as for the deviation between the via diameter and the land diameter of the photosensitive solder resist, the conventional 70 μm deviation can be reduced to 1/5 or less, and the supply of the tape carrier for the two-layer wiring TAB with stable positional deviation can be achieved. It becomes possible. For this reason, production yield and productivity are improved, and stable mass production can be provided.
[0042]
(2) The TAB tape manufacturing method of the present invention can be applied to the manufacture of Tape-BGA or CSP TAB tape, whereby the transport and bonding of semiconductor chips, and the alignment of solder balls. The assembly rate can be improved and the assembly rate of products can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a TAB exposure machine used in the manufacturing method of the present invention.
FIG. 2 is a process diagram showing one third of the manufacturing method according to an embodiment of the present invention.
FIG. 3 is a process diagram showing 2/3 of the manufacturing method according to an embodiment of the present invention.
FIG. 4 is a process diagram showing 3/3 of the manufacturing method according to an embodiment of the present invention.
FIG. 5 is a partial cross-sectional view of a TAB tape to be manufactured in one embodiment of the present invention.
FIG. 6 is a plan view showing a pattern example (a) created by the manufacturing method of the present invention in comparison with a pattern example (b) created by a conventional method.
FIG. 7 is a perspective view of a conventional TAB exposure machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insulating film 2, 3 Copper foil 4 Blind via 5 Wiring pattern 5a Land 6 Photoresist 7 Wiring pattern 7a Solder ball pad 8 Photosensitive solder resist 8a Non-resist area 9 Sn plating 10 Double-sided wiring TAB tape 11 Perforation hole 16 Optical sensor 17 Lighting device

Claims (4)

Form a wiring pattern on each copper foil bonded to both sides of the insulating film, connect a part of both wiring patterns by providing a blind via from the wiring pattern on one side to the inner surface of the wiring pattern on the other side, In the method of manufacturing a TAB tape in which a solder resist is provided in a predetermined region on the wiring pattern on the side where the blind via is provided, the wiring pattern formed by exposing and etching any one side of the copper foil is on the lower surface side. Set the exposure machine so that the alignment position of the wiring pattern on the lower surface side is read by the optical sensor, position the tape so that the read position matches the specified target position, and coat the photoresist beforehand. A method for producing a TAB tape, wherein pattern exposure is performed on a copper foil on an upper surface that has been pre-baked. 2. The method of manufacturing a TAB tape according to claim 1, wherein the pattern exposure is pattern exposure for forming a wiring pattern on the copper foil on the side where the blind via is provided. Method. 3. The method of manufacturing a TAB tape according to claim 1, wherein the pattern exposure is pattern exposure on a solder resist provided in a predetermined region on a wiring pattern for the copper foil on the side where the blind via is provided. A manufacturing method of a TAB tape characterized. 2. The method of manufacturing a TAB tape according to claim 1, wherein the pattern exposure is pattern exposure for forming a wiring pattern on the copper foil on the side where the blind via is not provided. Method.

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