JP2006049642A - Method of manufacturing double-sided interconnection tape carrier and tape carrier manufactured thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a double-sided interconnection tape carrier suitable for forming a fine pitch pattern. <P>SOLUTION: A polyimide film 201 has copper layers 203 bonded on both surfaces without using an adhesive. In the copper layer on one or both surfaces, a pattern for forming vias is formed by photo etching. With the pattern as a mask, a blind via hole 208 and a through hole are formed by polyimide etching using an alkali solution. Thereafter, a treatment for turning into a conductor is applied to the whole surface including the internal surface of the via hole and through hole, and the surface except for the via hole and through hole is masked by a resist before conducting interlayer connection by copper plating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tape carrier for mounting a semiconductor chip, and more particularly to a method for manufacturing a double-sided wiring tape carrier in which a copper wiring layer is formed on both sides of a polyimide tape.

  In recent years, electronic devices have been increasingly reduced in size, weight, and thickness, and there is a strict demand for higher integration of components used in the electronic devices. Conventionally, TCP (tape carrier package) using copper polyimide tape is known as a semiconductor package that can cope with fine pitch, but with the recent miniaturization of packages, the higher frequency of ICs has been accelerated. Along with this, higher frequency has been demanded for peripheral components on which semiconductors are mounted. Due to such demands for miniaturization and high frequency, it is essential to improve wiring density and high frequency characteristics in TCP, and a double-sided wiring tape carrier is desired to meet these demands.

  A conventional method for manufacturing a double-sided wiring tape carrier is shown in FIG. In the conventional manufacturing method, a copper pattern 102 for a via mask is formed on one side of a polyimide tape 101 with a double-sided copper layer using a photoresist, and then a carbon dioxide gas laser, an Ar laser, or the like is etched using the via mask. As a result, the blind via 103 is opened. Thereafter, as a pretreatment of the copper electroplating for electrical connection on both sides, a conductive layer 104 made of an electrically conductive material such as Pd or C is formed on the inner surface of the blind via, and a conductive treatment is performed. Next, copper plating 105 is deposited on the conductive layer by electrolytic copper plating to obtain an interlayer connection. Finally, the wiring 106 is formed by copper etching using a photoresist.

  However, in the conventional manufacturing method, since the plating is deposited on the entire surface by electrolytic copper plating after the formation of the conductive layer 104, the copper plating is deposited on the surface copper layer of the starting material. As a result, there is a problem that it is difficult to etch a fine pattern. In order to solve this problem, there is a method of reducing the thickness of the surface copper layer as a starting material, but for a fine pattern such as a 40 μm pitch, a surface copper layer having a thickness of about 8 μm is required. In the conventional manufacturing method, the thickness of 10 μm or more is required in the interlayer connection plating, and thus it has been impossible to obtain a copper thickness suitable for a fine pitch. Further, when the thickness of the interlayer connection plating is reduced to 10 μm or less, there has been a problem that in the reliability test, a crack is generated in the interlayer connection portion and the reliability is lowered.

  The present invention has been made in view of the problems of the prior art as described above, and an object of the present invention is to provide a method for manufacturing a double-sided wiring tape carrier suitable for forming a fine pitch pattern.

  In order to achieve the above object, a method for manufacturing a double-sided wiring tape carrier according to the present invention includes a via layer formed by photoetching on one or both sides of a polyimide film having a copper layer bonded on both sides without using an adhesive. After forming a pattern for opening and forming a blind via hole and a through hole by polyimide etching with an alkaline solution using the pattern as a mask, the entire surface including the inner surface of the via hole and the through hole is subjected to a conductive treatment, and further by copper plating Before the interlayer connection is performed, the portions other than the via hole and the through hole are masked with a resist.

  Also, the method for manufacturing a double-sided wiring tape carrier according to the present invention includes forming a via opening pattern by photoetching on one or both sides of a polyimide film having a copper layer bonded on both sides without using an adhesive. After forming blind via holes and through holes by laser using the pattern as a mask, the entire surface including the inner surfaces of the via holes and through holes is subjected to conductive treatment, and before the interlayer connection by copper plating, the via holes and through holes are formed. Other than the above, the resist is masked with a resist.

  According to the invention, preferably, the laser is a carbon dioxide laser or an argon laser.

  The tape carrier according to the present invention is manufactured by any one of the above manufacturing methods.

According to the manufacturing method of the present invention, in the copper plating step, the wiring formation region is masked with a resist, so that the copper thickness is not increased, and the original copper thickness is maintained, and the copper thickness suitable for fine pitch formation. Interlayer connection is possible while maintaining. In addition, the thickness of the surface copper layer suitable for any fine pitch can be maintained without being affected by the plating thickness of the interlayer connection, and a fine pattern can be easily formed.
In addition, according to the manufacturing method of the present invention, the masking resist is peeled off after copper plating, and the resist formation / exposure / development / etching process for wiring formation is performed again, so that a fine pitch can be formed. .

  Hereinafter, the present invention will be described with reference to FIG. First, a metal such as a Ni—Cr alloy is sputtered on both surfaces of the polyimide tape 201 as a starting material, and a metal layer 202 is formed on the polyimide surface. Next, a copper tape 203 is applied to the polyimide tape using the metal layer 202 as a power supply layer, and a double-sided copper tape with a double-sided copper layer 204 having a predetermined copper plating thickness is prepared. Next, an alkali development type photosensitive resist film 205 is laminated on both surfaces of the polyimide tape 204, the via mask pattern is exposed, and then developed with an aqueous sodium carbonate solution. Next, the resist patterned by development is etched with a copper chloride etchant to remove the copper in the via opening and the Ni—Cr layer as the underlying metal layer, thereby forming a via opening pattern 206. Next, the resist on both sides is peeled off with a sodium hydroxide solution to form a tape 207 in which polyimide is exposed only at the via opening. Next, the polyimide tape 207 is immersed in an alkali polyimide etching solution, and the polyimide layer is etched to form the blind via 208. Next, the entire surface of the substrate including the inner surface of the blind via hole is subjected to a conductive treatment using Pd, C, or the like. This processing step enables power supply by later electrolytic copper plating.

After this conductive treatment, an alkali developing type photosensitive resist is laminated on both surfaces, and the via hole pattern is exposed, and then developed with a sodium carbonate solution, only the via hole is opened, and the others are masked with the resist. Next, copper plating is deposited only on the inner surface of the via hole by electrolytic copper plating, and the copper foils on both sides are electrically connected. In the copper plating process, since the wiring formation region is masked with a resist, copper plating does not deposit and the copper thickness remains unchanged.
Next, the masking resist is stripped with an alkali, and an alkali development type photosensitive resist is laminated on both sides again, after exposing a predetermined wiring pattern, developed with a sodium carbonate solution, etched with a copper chloride etchant, The copper layer 203 and the Ni—Cr metal layer 202 are removed, and the formation of the wiring 212 is completed. At this time, since the copper thickness remains unchanged, the copper thickness suitable for the desired pitch remains unchanged, and fine pitch correspondence can be easily performed.
Finally, the resist is removed to obtain a double-sided wiring tape carrier 213. If necessary, Ni / Au plating or solder resist formation may be performed on the double-sided wiring tape carrier.

  Hereinafter, an embodiment will be described with reference to FIG. FIG. 1 shows an embodiment of the present invention and shows a cross-sectional view of each process of a double-sided wiring tape carrier. First, a Ni—Cr alloy was sputtered to a thickness of about 500 mm on both surfaces of a 50 μm-thick polyimide tape 201 as a starting material to form a metal layer 202. Further, a copper plating layer 203 having a thickness of 8 μm was formed on both sides by copper plating, and a polyimide tape 204 with a double-sided copper layer was prepared. Next, after laminating an alkali-developable photosensitive resist film 205 (AQ-1558 manufactured by Asahi Kasei Co., Ltd.) on both surfaces of the polyimide tape 204, a mask pattern for opening a 150 μmφ via is exposed, and then a 1 wt% sodium carbonate aqueous solution is added. Development was performed at 40 ° C. for 30 seconds. Next, the resist patterned by development is etched with a 10 wt% copper chloride etchant at 45 ° C. for 30 seconds to remove the copper on the upper surface of the via opening and the underlying Ni—Cr metal layer, and the 150 μmφ via mask 206. Formed. Next, the resist on both sides was treated with a 2 wt% sodium hydroxide solution at 30 ° C. for 3 minutes to remove the resist, thereby forming a tape 207 in which polyimide was exposed only at the via opening. This polyimide tape 207 was immersed in an alkali polyimide etching solution at 70 ° C. for 2 minutes, and the polyimide layer was etched to form a blind via 208.

Next, in order to conduct the conductive treatment on the side surface and the entire surface of the blind via hole, after immersion in an alkaline degreasing solution at 40 ° C. for 5 minutes, immersion in a Sn-Pd solution at 60 ° C. for 5 minutes, pickling with a 10% sulfuric acid solution, A Pd adsorption layer for electrical conduction was formed. Thereafter, an alkali-developable photosensitive resist (Asahi Kasei AQ-1558) was laminated on both sides, pattern exposure was performed so that only via holes were opened, and development was carried out at 30 ° C. for 30 seconds with a 1% Na ₂ CO ₃ solution.
Next, in order to perform interlayer connection by copper sulfate plating, first, degreasing was performed at 40 ° C. for 1 minute, and then chemical polishing (sulfuric acid-hydrogen peroxide system) was performed at room temperature for 30 seconds. Further, pickling with 10% sulfuric acid was performed to complete the pretreatment. Next, electrolytic copper plating was performed using copper sulfate plating to deposit about 10 μm of copper plating on the Pd conductive layer, and connection with the upper and lower conductive foils was obtained. In the copper plating step, since portions other than the interlayer connection portions are masked with resist, copper plating does not deposit on the subsequent wiring formation surface, and the copper thickness remains unchanged. Next, the masking resist 217 was removed to obtain a tape 213 with both sides connected.
Further, in order to form a wiring, an alkali development type photosensitive resist (Asahi Kasei SPG-102) was laminated again on both surfaces, and a fine wiring pattern with a pitch of 40 μm was exposed, and then developed with a 1 wt% sodium carbonate solution. Next, etching was performed with a 10 wt% copper chloride etching solution to remove the copper layer and the Ni—Cr metal layer, and the pattern formation of the wiring 212 was completed. Finally, the resist was peeled off at 2 ° C. for 1 minute at 40 ° C. to obtain a double-sided wiring tape carrier.

  As a result of observing the appearance of the fine pattern wiring part of the double-sided wiring tape carrier thus obtained, there was no short circuit between the wirings, and the wiring formation was good. Also, from the cross-sectional observation of the interlayer connection, no cracks or internal voids were observed, and the obtained tape carrier was alternately immersed in silicone oil at 260 ° C. and room temperature for 100 cycles, and the resistance value before and after the test was changed. As a result of measuring the rate, the rate of change before and after the test was within 3%, and sufficient reliability was ensured.

It is process drawing which shows the manufacturing method of the double-sided wiring tape carrier based on this invention. It is process drawing which shows the manufacturing method of the conventional double-sided wiring tape carrier.

Explanation of symbols

201 Polyimide film
202 seed layer
203 copper layer
204 Polyimide tape with double-sided copper layer
205 resist
206 Via Mask
207 Tape with via mask
208 Blind via by polyimide etching
212 Wiring
213 Double-sided wiring tape carrier of the present invention

Claims (5)

  A pattern for via opening is formed by photoetching on one or both sides of a polyimide film having a copper layer bonded on both sides without using an adhesive, and the pattern is used as a mask for polyimide etching with an alkaline solution. After forming the blind via hole and the through hole, the entire surface including the inner surface of the via hole and the through hole is subjected to a conductive treatment, and before performing interlayer connection by copper plating, masking other than the via hole and the through hole with a resist. A manufacturing method of a double-sided wiring tape carrier characterized by the above.   A via hole pattern is formed by photoetching on one or both sides of a polyimide film having a copper layer bonded on both sides without using an adhesive, and blind via holes and through holes are formed by laser using the pattern as a mask. Double-sided wiring tape, characterized in that after the formation, the entire surface including the inner surface of the via hole and the through hole is subjected to a conductive treatment, and further, other than the via hole and the through hole are masked with a resist before performing interlayer connection by copper plating Carrier manufacturing method.   The method for manufacturing a double-sided wiring tape carrier according to claim 2, wherein the laser is a carbon dioxide laser or an argon laser.   2. A tape carrier manufactured by the manufacturing method according to claim 1. A tape carrier manufactured by the manufacturing method according to claim 2.