JP4250861B2 - Film carrier manufacturing method - Google Patents

Description

【００４９】
実施例１では、断面観察、孔内断線のいずれも生じず、優れた効果を奏することが確認された。
実施例２では、孔径が小さくなるにつれて、孔内のめっき膜厚が薄くなる現象が生じたが、問題がないと判断された。
【００５０】
比較例１では、孔径が小さいとビア開口径の調整が難しく、ビアが大きくなった。具体的には４０μmφの目標が５０μmφとなった。ビアエッチング時に開口内にエッチング液が溜まりやすく、エッチングが進んでしまうものと想像された。また、工程が増えるため、製造効率が低下した。
【００５１】
比較例２では、一括照射による銅の飛散によりビア付近にバンプを形成するが、研磨加工を施さなかった結果、何れのビア径のサンプルに於いても、ビア周囲にコブが形成した。また、６０μｍφと４０μｍφのサンプルでは、ビア内のめっき成長も不均一で、ビア内にボイドが形成され、プレッシャークッカー試験器に入れた後では断線が生じた。
【００５２】
比較例３では、評価に於いては本発明の実施例と同等の結果を得た。しかし、無電解銅めっきに長時間を要し、ラインスピードを遅くしなければならず、製造効率が低かった。
【００５３】
【発明の効果】
請求項1記載の発明によれば、少なくとも、（ａ）長尺状の絶縁性フィルムの両面に第一導体層及び第二導体層を有する基材を使用し、前記絶縁性フィルムの両端に長手方向に沿って複数のスプロケットホールを形成する工程、（ｂ）前記絶縁性フィルムの一方の面よりレーザー光を照射し、第一導体層と絶縁性フィルムを貫通し、第二導体層に達する直径１２０μｍ以下の導通用孔を形成する工程、（ｃ）前記第一導体層及び第二導体層の表面を、研磨して平坦化する工程、（ｄ）前記導通用孔の壁面に、パラジウム微粒子、カーボン、導電性ポリマーから選ばれる薄膜導体を付着させる工程、（ｅ）電解めっきにより、少なくとも導通用孔内に導電層を形成する工程、（ｆ）前記第一導体層及び第二導体層をエッチングし、配線層を形成する工程、（ｇ） 第一導体層及び第二導体層上に、ソルダーレジスト層を形成する工程、の各工程からなるため、レーザー加工前に銅箔のエッチング工程が不要で、無電解めっきやスパッタリングのような、長時間を要する処理を行う必要がなく、また設備も小さくでき、従って非常に高い効率で電気的信頼性も優れるフィルムキャリアを製造することが可能となる。
また、設備を小さくできるということは、設備コストの低減のみならず、設備を通過する時間の短縮もできるため、製造効率が高くなる。そして、リールツーリールでの製造を可能にする優れた製造方法である。
【００５４】
また、請求項２記載の発明によれば、請求項１記載のフィルムキャリアの製造方法において、前記（ｅ）工程として、電解めっきにより導通用孔の内壁に導電層を形成する工程と、導通用孔内を樹脂埋めする工程とを行うため、樹脂が導通用孔内壁の導電層を補強し、従って電気的信頼性の高いフィルムキャリアを製造することが可能となる。
【００５５】
そして、請求項３記載の発明によれば、請求項１記載のフィルムキャリアの製造方法において、前記（ｅ）工程の電解めっきにより、導通用孔内を埋めるため、導通用孔内の接続信頼性がより確実なものとなり、従って電気的信頼性の高いフィルムキャリアを製造することが可能となる。
【００５６】
さらに、請求項４記載の発明によれば、請求項１乃至請求項３のいずれか一項記載のフィルムキャリアの製造方法において、前記（ａ）乃至（ｇ）の工程をリールツーリールで行うため、極めて高い製造効率で、電気的信頼性の高いフィルムキャリアを製造することが可能となる。
【図面の簡単な説明】
【図１】 本発明の一実施形態にかかるフィルムキャリアの構成を示す図
【図２】 同実施形態における２−２線矢視断面図
【図３】同実施形態におけるフィルムキャリアの製造方法を説明するための工程断面図
【図４】同実施形態におけるフィルムキャリアの製造方法を説明するための工程断面図
【符号の説明】
１０・・・フィルムキャリア
１１・・・絶縁性フィルム
１２・・・接着剤層
１３・・・スプロケットホール
１４・・・導通孔
１５・・・薄膜導体
１５ｂ・・・導電層
１６・・・パッド電極
１７ａ、ｂ・・・銅箔
１８・・・配線パターン
１９・・・ソルダーレジスト層
２０・・・（感光性材料からなる）フォトソルダーレジスト層
２１・・・半田ボール実装孔
３０・・・銅突起物
４０・・・レジスト層
５０・・・銅箔付ポリイミドフィルム
Ｄ・・・デスミア液
Ｌ・・・レーザー光
ＵＶ・・・露光光[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for producing a film carrier having wiring layers on both sides of an insulating film.
[0002]
[Prior art]
  In general, a film carrier is a wiring carrier formed on an insulating film, such as a mobile phone, a game machine, a television, a radio, a VTR, an audio device, a consumer device, an electronic computer, an OA device, an electronic application device, Widely used in industrial equipment such as electrical measuring instruments and communication equipment.
[0003]
  In addition, there is an increasing demand for these electronic devices to achieve higher performance and further miniaturization. In order to meet the demands for higher performance and compactness, film carriers as electronic device parts are also rapidly becoming smaller, higher pin count, and higher performance in electronic devices. The diameter of via holes, the diameter of lands and pads, the number of layers, and the fineness are rapidly increasing.
[0004]
  Moreover, as an insulating film used for a film carrier, epoxy resin, phenol resin, acrylic resin and the like have been used conventionally, but in particular, a polyimide film, a polyester film, etc. excellent in mechanical degree and heat resistance are used. Furthermore, development of fluororesin and polyphenyl ether resin is progressing from the viewpoint of higher performance. In addition, the development of resins that have been studied from the viewpoint of environmental measures is also in progress.
[0005]
  Previously, single-sided film carriers with wiring formed on only one side of the insulating film were used for film carriers, but circuit patterns were formed on both sides of the insulating film to further increase density and improve productivity. There has been a need for a double-sided film carrier.
  The manufacturing method of a general double-sided film carrier is given. That is, an insulating film having metal foil on both sides is used, laser processing is performed from one side, and hole processing is performed on the copper foil and the insulating film on one side. Alternatively, after chemically etching the copper foil on one surface, laser drilling or polyimide etching is performed on the hole, and the insulating film is subjected to hole processing. However, when the hole diameter is small, highly accurate chemical etching is performed. Since it is difficult, there exists a problem that a hole diameter and a shape change. Moreover, since chemical etching is performed, the number of processes is increased, resulting in high cost production.
  Subsequently, after conducting the conductive treatment by electroless plating or sputtering in the conductive hole, electrolytic plating is performed to form a metal layer that electrically connects the conductor layers on both sides. And a wiring pattern, an electrode pad, etc. are patterned on metal foil. By completing this patterning, a film carrier on which a semiconductor chip can be mounted is completed.
  After the film carrier is completed, a semiconductor device that can be mounted on a mother board or the like of an external element is manufactured by mounting a semiconductor chip and sealing with resin.
[0006]
  Incidentally, a reel-to-reel method has been known as a method for manufacturing a film carrier. This is a method for continuously manufacturing part or all of the manufacturing process in a reel shape by utilizing the flexibility.
  That is, a film carrier is manufactured by a method in which the film material is wound in a reel shape, the film is unwound from one side of the production line, the above-described processing steps are performed, and finally the winding is performed. A film carrier can be manufactured. It is not always necessary to wind up at the end, and a step of cutting into a desired shape in the final step can be taken.
[0007]
[Problems to be solved by the invention]
  However, since electroless plating or sputtering is used for the conductive treatment, there is a drawback that the treatment takes time. Sputtering must be performed in a vacuum chamber. Considering the evacuation time, it takes much time, and it is inevitable that the equipment becomes large. In electroless plating, the pretreatment process is long, the plating itself takes time, and the equipment becomes large, so the processing time has to be long. In particular, when manufacturing by the reel-to-reel method, if time is required for a specific process as described above, it is necessary to determine the film feeding speed in accordance with the process, resulting in an increase in manufacturing efficiency. .
  In electroless plating, the plating solution tends to be unstable, and a more stable manufacturing method has been desired for mass production. When the plating solution is in an unstable state, a defect occurs in electroless plating, and also affects electrolytic plating, resulting in a decrease in connection reliability. In addition, in electroless plating, plating metal deposits on unnecessary parts such as the wall of the plating tank, and some of them fall into the liquid and reattach to the surface of the film, causing defects such as short circuits. There was also the problem of creating. Then, when an electronic component such as a semiconductor chip is connected to the film carrier or used, there is a problem that the insulating film expands due to moisture absorption, heat, etc., and a crack is generated in the conduction hole.
  That is, there is a problem in that the electrical reliability is lowered such that the connection reliability is lowered, a defect causing a short circuit is generated, or a crack is generated.
[0008]
  The present invention has been made in view of the above-mentioned problems, and a problem is to provide a manufacturing method capable of improving electrical reliability and manufacturing a film carrier with high manufacturing efficiency. .
[0009]
[Means for Solving the Problems]
  The present invention solves this problem, and the invention of claim 1
  The film carrier manufacturing method is characterized by including at least the following steps (a) to (g).
(A) The process which uses the base material which has a 1st conductor layer and a 2nd conductor layer on both surfaces of an elongate insulating film, and forms a some sprocket hole along a longitudinal direction at the both ends of the said insulating film .
(B) Laser from one side of the insulating film-A step of irradiating light to form a conduction hole having a diameter of 120 μm or less reaching the second conductor layer through the first conductor layer and the insulating film.
(C) A step of polishing and flattening the surfaces of the first conductor layer and the second conductor layer.
(D) The wall surface of the hole for conduction is selected from palladium fine particles, carbon, and a conductive polymer.Thin film conductorThe process of attaching.
(E) A step of forming a conductive layer at least in the hole for conduction by electrolytic plating.
(F) A step of etching the first conductor layer and the second conductor layer to form a wiring layer.
(G) A step of forming a solder resist layer on the first conductor layer and the second conductor layer.
[0010]
  The invention of claim 2 of the present invention
2. The film carrier according to claim 1, wherein the step (e) includes a step of forming a conductive layer on the inner wall of the hole for conduction by electrolytic plating and a step of filling the inside of the hole for conduction with a resin. It is a method.
[0011]
  The invention of claim 3 of the present invention
The method for manufacturing a film carrier according to claim 1, wherein the hole for conduction is filled by electrolytic plating in the step (e).
[0012]
  The invention of claim 4 of the present invention
The film carrier manufacturing method according to any one of claims 1 to 3, wherein the steps (a) to (g) are performed by a reel-to-reel method.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
  FIG.Is a schematic diagram showing the configuration of a film carrier according to an embodiment of the present invention,FIG.IsFIG.FIG. 2 is a sectional view taken along line 2-2. This film carrier 10 has adhesive layers 12 on both sides of an insulating film 11 that can be wound up,Copper foil 17a, 17bThe sprocket holes 13 are formed along the longitudinal direction of the film with copper foil, and between the sprocket holes 13 at both ends,Wiring pattern 18WhenPad electrode 16For each side of the structure of the film 11 and the adhesive 12,Wiring pattern 18WhenPad electrode 16Is a conduction hole14Formed inConductive layer 15bIt is the structure connected by.
[0014]
  Here, the film carrier 10 mainly includes polyimide, polymer liquid crystal, phenol resin, acrylic resin, polyester, fluorine resin, and polyphenyl ether resin in terms of dielectric constant and thermal expansion coefficient required as a wiring board. It is done. The double-sided wiring board uses a composite material in which metal layers such as copper and aluminum are formed on both surfaces of these insulating films. This is because the metal foil was pasted on both sides of the insulating film using a polyimide or epoxy adhesive.Film with copper foilOr metal by electrolytic metal plating after processing such as sputteringlayerFormedFilm with copper foilIt is. Also, by applying a liquid polyimide material to the copper foil and bonding it togetherFilm with copper foiland so on.
[0015]
  For example,Polyimide film with copper foil 50As: Espanex (manufactured by NS A product sold under a trade name such as (manufactured by Sumitomo Metal Mining Co., Ltd.) can be used. These can arbitrarily select standard values such as the thickness of the polyimide film, the thickness of the copper foil, and the width of the film. Also in the present invention, a starting material having a standard value that is a value decided between parties as a specification of the final product is used and processed. From the viewpoint of workability, the thickness of the polyimide film is preferably about 25 to 75 μm, and the thickness of the copper foil is preferably about 1 to 15 μm. In particular, if the copper foil becomes too thick, it becomes difficult to form a fine pattern.
[0016]
(First embodiment)
  Next, a first embodiment of the film carrier manufacturing method as described above will be described with reference to FIGS. As shown in FIG. 3 (a), an adhesive layer 12 made of an adhesive tape is stuck on both sides of a long insulating film 11 made of a polyimide film, and the thickness is further increased through the adhesive layer 12. The film 11 to which the 12 μm copper foils 17a and 17b are attached is cut into a predetermined width to produce a polyimide film 50 with copper foil. This is the state wound on the reel.
[0017]
  Next, while unwinding from the reel, as shown in FIG.50Sprocket holes 13 are formed by punching along the longitudinal direction of both ends of the.Been formedSprocket hole 13 is a film carrier10In this manufacturing process, it is necessary when the tape material is continuously conveyed by the reel-to-reel method, and is formed for the purpose of ensuring positional accuracy in each processing in the subsequent process.
[0018]
  Next, as shown in FIG. 3C, a conduction hole 14 is formed in the film carrier 10 in which the sprocket hole 13 is produced. In order to form the conductive hole 14, a UV-YAG laser processing machine is used, and the laser spot diameter is 10 to 140 μm, and the hole is processed from the copper foil 17a side under irradiation conditions suitable for each diameter. For positioning of the conduction hole, a method of controlling the position of the laser beam or a method of using a mask such as a glass plate can be used. For example, as for the laser processing conditions in the case of a 40 μm diameter, 0.3 mJ / shot can penetrate through the copper foil with 4 shots, and 0.036 mJ / shot with 30 shots can penetrate the polyimide.
Examples of the laser include solid lasers such as YAG, YLF, YAP, and YVO4, and a carbon dioxide gas laser.
  However, in principle, carbon dioxide lasers are processed by heat, so if holes are drilled, holes that penetrate the film substrate can be formed. It is difficult to process only the one copper foil layer and the insulating material layer and stop the processing on the upper surface of the second copper foil layer. Therefore, when using a carbon dioxide laser, it is preferable to use a copper foil of 13 μm or less as the first copper foil. Further, when the carbon dioxide laser does not use a mask, it is difficult to narrow the beam. Therefore, it is preferable to use the above-mentioned solid-state laser.
  The diameter of the conduction hole is preferably 120 μm or less. This is because the plating solution penetrates well and is easy to update. Therefore, the plating thickness in the hole can be easily increased, and the resin filling in the via can be reliably performed. In the case of a via having a size exceeding 120 μm, the supply of the solder resist filled with resin is insufficient, and insulation may be incomplete.
[0019]
  Above film carrier10After laser processing, copper is not removed when laser processing is applied to the copper foil surface of the conduction hole.MeltingButMeltingPart of the periphery of the conduction holeCopper foil 17aA protrusion 30 is formed on the surface.
  Next, as shown in FIG.3 (d), in order to remove this, it grind | polishes using a grinder and leveles the whole copper surface.
  In the polishing step, plating is abnormally deposited starting from the protrusion 30 in the subsequent electroplating step,Blocking the upper part of the hole to form a void inside, affecting the electrical reliabilitySuch asSince there is a possibility, the occurrence of such a defect can be prevented by polishing and removing.
  Examples of the polishing machine used for this polishing process include buffing, paper polishing, sand blasting, and wet blasting.
[0020]
  For example, in the case of buff polishing, first, a smooth copper foil surface is obtained by performing buff polishing with a roughness of # 800 and then performing buff polishing with # 1000 for finishing. Industrially, one side or both sides of the tape is polished by continuously passing the tape through a polishing machine using a rotating cylindrical buffaloer.
[0021]
  Inside the conduction hole 14 formed by the laser processing, smear due to heat and light reaction during processing remains or adheres. This may impair the bondability between the copper plating layer to be formed in the subsequent process and the copper foil layer at the bottom of the hole, so a desmear process for removing smear is performed to ensure the reliability of the bond. Is preferred.
  Next, as shown in FIG. 4A, smear is removed by a known method in which a chemical solution containing a permanganate is allowed to act. A general smear removing step is composed of three steps: (1) swelling (2) desmear (3) neutralization, and in the present invention, these steps are sequentially performed. As the chemical solution used, one for processing a multilayer printed wiring board can be used. For example, Enplate MLB-496, 497, 790 (manufactured by Meltex) can be used. Normally, when a UV-YAG laser is used, it is possible to reduce the occurrence of smear as compared with the case where a carbon dioxide laser is used. Therefore, the desmear condition in the present invention is also a general condition. In comparison, the processing time can be shortened.
[0022]
  Next, as shown in FIG. 4B, on the wall surface of the conduction hole 14.Thin film conductor 15To attach.Thin film conductor 15Is selected from palladium fine particles, carbon, and conductive polymer. The treatment for attaching the palladium fine particles further includes a treatment using a tin-palladium colloid, a treatment using a palladium organic colloid, a treatment for adsorbing and reducing palladium ions such as tin-free palladium ions, and the like. These are known as direct plating systems.
[0023]
  Among them, polyimideWhenSince it is excellent in adhesion to copper plating, stability of the plating process, uniformity of plating thickness in the conduction hole, etc., a step of attaching palladium fine particles is preferable, and a treatment using tin-palladium colloid is particularly preferable.
[0024]
  Hereinafter, the process using a tin-palladium colloid will be described as an example.
  In the conductive treatment, the film carrier is immersed in a treatment liquid to form a conductive film that is a tin-palladium colloid on the copper foil, the insulating material, and the surface of the base resin in the conductive hole.
  This treatment is performed by sequentially immersing the material in a series of adjusted chemicals and repeating the cleaning.
[0025]
  This direct platingsystemThe process for the conductive treatment by is composed of the following processes.
(1) Conditioning The surface of the substrate is wetted and conditioned so as to promote the adsorption of the tin-palladium colloid in the subsequent step. The main components of the liquid include nonionic surfactants, cationic surfactants (each 0.1 to 10 g / L) and copper (+2) ion complexing agents such as triethanolamine (1 to 100 g / L). ).
(2) Soft etching The surface of the copper foil is roughened and brought into close contact with the electroplated copper layer. The main component of the liquid is sodium persulfate(10-200g / L), Sulfuric acid(1-50mL / L)Is appropriate.
(3) Pickling The oxide on the surface of the copper foil is dissolved and removed. The main component of the liquid is sulfuric acid(1-100g / L)Is appropriate.
(4) Pre-dip Since the tin-palladium colloid in the catalyst liquid comes into contact with water with a low chloride ion concentration, the substrate is immersed in a liquid with a high chloride ion concentration as the previous step. Bring it to the next stage catalyst. The main component of the liquid is sodium chloride(50-300g / L), Hydrochloric acid (35%)(10-100mL / L)Is appropriate.
(5) Catalyst To adsorb the surface of the substrate, tin-palladium colloid is adsorbed. The main component of the liquid is palladium(20-200 mg / L), Tin chloride (+2)(5g / L or more)And sodium chloride(50-300g / L), Hydrochloric acid (35%)(10-100mL / L)Is appropriate. Palladium and tin chloride are reacted in advance by mixing in a reaction vessel containing a hydrochloric acid solution when heated to form a tin-palladium colloid, and then added to a solution in which sodium chloride and hydrochloric acid are dissolved. Adjust the liquid.
(6) Accelerator Remove excess tin from the tin-palladium colloid. The main component of the liquid is sulfuric acid(10-200g / L)Or sodium hydroxide(5 to 200 g / L)Is appropriate.
  In addition, a process including such a series of steps is also received from each supplier.As a direct plating systemThey are commercially available and can be used. For example, conductron DP-H (manufactured by Meltex), EE-1 (manufactured by Uemura Kogyo Co., Ltd.), risertron (manufactured by Sugawara Eugelite), Ecolut (manufactured by Japan Energy), and the like can be mentioned.
[0026]
  Subsequently, as shown in FIG.Thin film conductor 15,Copper foil 17a, 17bIs used as a cathode electrode, and an electrolytic copper plating is performed using a copper sulfate plating solution, and the inside of the conduction hole 14 andCopper foil 17aOn the surfaceConductive layer 15bIs formed.Copper foil 17aas well asCopper foil 17bAre electrically connected through the conduction hole 14. However,Copper foil 17bWhen copper plating is not applied to the surface, it is necessary to form a protective layer by printing a liquid resist or laminating a dry film resist or an adhesive tape to protect it from contact with the plating solution.
[0027]
  The main components of the copper sulfate plating solution are copper sulfate and sulfuric acid, and their concentrations are as follows, for example.
  Copper sulfate (copper sulfate pentahydrate) 40-230 g / L
  Sulfuric acid (98%) 50-200 g / L
  As plating conditions, the liquid temperature is 20 to 30 ° C., and the current density is 0.5 to 2 A / dm.²Is appropriate.
[0028]
  This copper plating fills the hole for conduction, and the additive used is for hole filling plating. This is different from the conventional additive for through-hole plating in the mode of copper deposition. The deposition rate in the surface of the hole for conduction and in the hole for conduction is the same or higher in the case of the conventional additive, whereas the rate of deposition in the hole is larger in the hole. Become. This effect is because, in the additive for hole-filling plating, the additive component is selectively adsorbed on the surface rather than the inside of the hole to suppress the precipitation of the portion, and the deposition rate in the hole is relatively high. It is considered to be. Examples of components of additives that produce such effects include the following.
  SPS (bis (3-sulfopropyl) disulfide disodium salt) 0.1-10ppm
  Polyethylene glycol 10-1000ppm
  Janus Green B 1-100ppm
  Chlorine 30-100ppm
  The average molecular weight of polyethylene glycol is suitably 500-20000.
  When filling the hole in the conduction hole, if applied to a conduction hole having a small diameter of 120 μm or less, particularly 60 μm or less, the plating deposition rate is high due to current concentration at the entrance of the hole. The upper part of the hole is closed before the copper plating filling is completed, and a space, so-called void is easily generated inside. Therefore, by selecting additives with high leveling characteristics and processing using a PR power source as a plating power source, the copper plating deposition in the conduction holes is preferentially promoted to completely eliminate the generation of plating voids. Can do. The PR power supply temporarily reverses the positive and negative electrodes.
[0029]
  By performing hole-filling plating, the electrical connection of the holes for conduction is strengthened, and when connecting electronic parts such as semiconductor chips to the film carrier or connecting and using them as electronic parts, Even in a humid environment, the insulating film does not expand due to moisture absorption, heat, etc., and cracks do not occur in the conduction holes.
[0030]
  Subsequently, as shown in FIG. 4D, in the wiring etching process, a liquid photosensitive resist or a film-type photosensitive resist is coated on the copper foil surface in the same manner as in the prior art, and the resist layer 40 is formed. The pattern is exposed and developed using a photolithography process.
[0031]
  Subsequently, as shown in FIG. 4 (e), using the photolithography pattern obtained as a mask, the copper foil is etched with a ferric chloride etchant,Wiring pattern 18WhenPad electrode 16Is formed. This wiring etching process includes batch resist printing, batch exposure, batch development, and batch etching.(Including resist stripping)However, it is not limited to this method.
[0032]
  Subsequently, as shown in FIG. 4F, a solder resist layer 19 is formed by printing a solder resist on the circuit pattern by screen printing or the like for the purpose of protection from the external environment of the formed circuit. As the solder resist material, those used in TAB or the like as tape printed circuit board materials can be used. It may or may not have photosensitivity. When a non-photosensitive material is used and patterning is performed for the purpose of exposing the electrode, laser processing or the like is performed.
  For example, S-500 (manufactured by Taiyo Ink) is suitable for those having photosensitivity, and PSR-4000 (manufactured by Taiyo Ink), DSR-2200 (manufactured by Tamura Seisakusho) are suitable for those not having photosensitivity. is there.
[0033]
  Subsequently, as shown in FIG. 4 (g), a photo solder resist made of a photosensitive material is applied on the circuit pattern by screen printing or the like for the purpose of protecting the external environment of the formed circuit and aligning the bonding position of the solder ball. To do. Subsequently, as shown in FIG. 4 (h), the solder ball bonding hole 21 is formed on the pad electrode 16 by exposing the developed photo solder resist layer 20 made of a photosensitive material to UV through a mask and developing it. Is done.
[0034]
(Second embodiment)
  Although it manufactures by the method similar to 1st embodiment, it replaces with the plating solution of 1st embodiment, and uses the plating solution for through holes. As a result, a conduction hole that is not filled is formed.
[0035]
(Third embodiment)
  Although it manufactures by the method similar to 2nd embodiment, after plating in the state which does not fill a hole, resin is filled into a hole by screen printing. Thereby, a hole for conduction in which the inside of the hole is filled with resin is formed.
  Examples of the resin used for resin filling include S-500 (manufactured by Taiyo Ink), PSR-4000 (manufactured by Taiyo Ink), DSR-2200 (manufactured by Tamura Seisakusho), and the like. Moreover, what has electroconductivity may be sufficient.
  By filling the resin,Conductive layerWhen the electronic component such as a semiconductor chip is connected to the film carrier.,Or,Even when connected and used as an electronic component, the insulating film does not expand due to moisture absorption, heat, etc. even if it is placed in a high-temperature and high-humidity environment, and cracks do not occur in the conductive holes.
[0036]
【Example】
  (Example 1)
  Next, Example 1 will be described with reference to FIGS. As shown in FIG. 3 (a), an adhesive layer 12 made of an adhesive tape is attached to both surfaces of an insulating film 11 made of a polyimide film having a thickness of 50 μm, and the thickness is further increased through the adhesive layer 12. 12 μmCopper foil 17a, 17bCut the film 11 with a 48 mm width,Polyimide film with copper foil 50Was made. This is the state wound on the reel.
[0037]
  Next, while unwinding from the reel, as shown in FIG.50Sprocket holes 13 were formed by punching along the longitudinal direction of both ends of the. Next, as shown in FIG. 3 (c), the film carrier on which the sprocket hole 13 was produced.10In addition, using a UV-YAG laser processing machine,Copper foil 17aBy drilling holes from the side, conductive hole 14 having a hole diameter of 100 μm was formed. Next, as shown in FIG. 3D, buff polishing with a roughness of # 800 was performed, and the entire copper surface was leveled by performing buff polishing with # 1000 for finishing.
[0038]
  Next, as shown in FIG. 4A, a desmear process was performed using Enplate MLB-496 (manufactured by Meltex). Next, as shown in FIG. 4B, a conductive material is attached to the wall surface of the conduction hole 14. The following steps were performed.
・ Conditioning Conductron DP-H Conditioner (Meltex)
                50 ° C, 10 seconds
・ Soft etching sodium persulfate 100g / L, sulfuric acid 30g / L
                25 ° C, 30 seconds
・ Pickling sulfuric acid 100g / L
                25 ° C, 10 seconds
・ Pre-dip Conductron DP-H Pre-dip liquid (Meltex)
                25 ° C, 10 seconds
・ Catalyst Conductron DP-H Activator (Meltex)
                45 ° C, 30 seconds
・ Accelerator Conductron DP-H Accelerator (Meltex)
                50 ° C, 30 seconds
[0039]
  Subsequently, as shown in FIG.Thin film conductor 15,Copper foil 17a, 17bAs a cathode electrode, and electrolytic copper plating is applied to the inside of the conduction hole 14 andCopper foil 17aA copper plating layer was formed on the surface. The inside of the conduction hole was filled.Copper foil 17aas well asCopper foil 17bWere electrically connected through the conduction hole 14. here,Copper foil 17bOn the surface, a dry film resist was laminated and copper plating was not performed.
[0040]
  A copper plating solution having the following composition was used.
    Copper sulfate pentahydrate 180g / L
    Sulfuric acid 55g / L
SPS (bis (3-sulfopropyl) disulfide disodium salt) 1ppm
Polyethylene glycol (molecular weight 7500) 400ppm
Janus Green B 10ppm
Chlorine 60ppm
Plating condition is current density 1A / dm²The plating time was adjusted so that the deposited film thickness was 15 μm.
[0041]
  Subsequently, as shown in FIG.40Was formed with a thickness of 15 μm, and a desired pattern was exposed and developed in a photolithography process. Subsequently, as shown in FIG. 4 (e), the resulting photolithography pattern mask was used, and the copper foil was etched with a ferric chloride etchant.Wiring pattern 18WhenPad electrode 16Formed.
[0042]
  Subsequently, as shown in FIG. 4 (f), a solder resist was applied on the wiring pattern 18 with a thickness of 20 μm to form a solder resist layer 19 for the purpose of protection from the external environment of the formed circuit.
  Subsequently, as shown in FIG. 4G, a solder resist made of a photosensitive material was applied on the pad electrode 16. Then, as shown in FIG. 4H, exposure and development were performed to form a 25 μm-thick photo solder resist layer 20 in which solder ball bonding holes 21 were formed on the pad electrodes 16. And the thing of the hole diameter of 60 micrometers and 40 micrometers similarly for the hole for conduction | electrical_connection was also produced.
[0043]
  (Example 2)
  Although manufactured by the same method as Example 1, ST-901 (made by Meltex), which is a plating solution for through holes, was used instead of the plating solution of Example 1. Thereby, the hole for conduction | electrical_connection which was not filled up was formed.
  And the thing of the hole diameter of 60 micrometers and 40 micrometers similarly for the hole for conduction | electrical_connection was also produced.
[0044]
  (Comparative Example 1)
  Although it manufactured by the method similar to Example 1, as a difference, the copper foil of the side irradiated with a laser was first etched beforehand at the time of the laser processing of the hole for conduction | electrical_connection.
[0045]
  (Comparative Example 2)
  Although it manufactured by the method similar to Example 1, as a difference, the grinding | polishing process of the copper foil surface was not performed after laser processing.
[0046]
  (Comparative Example 3)
  Although manufactured by the same method as in Example 1, the difference was that after the polishing process of the copper foil surface after laser processing, instead of the process of attaching a conductive material of palladium fine particles to the wall surface of the hole for conduction, 0.5 μm Of electroless copper plating. It took 15 minutes only for the time of immersion in the electroless plating solution, excluding the pretreatment of electroless plating. Thereafter, electrolytic copper plating was performed in the same manner as in Example 1.
[0047]
  The state after copper plating was evaluated by cross-sectional observation, and the results are shown in the A column of the following table. Moreover, after putting these samples in 125 degreeC and a 100% pressure cooker tester for 100 hours, the disconnection evaluation of the state after being immersed in 260 degreeC molten solder (Sn / Pb = 63/37%) for 30 seconds is performed. The results are shown in the B column of the following table.
  In Table 1, in column A, a circle indicates that there was no problem in the cross-sectional observation result of the via hole. For the column B, a circle indicates that there was no break in the hole.
[0048]
[Table 1]

[0049]
  In Example 1, it was confirmed that neither cross-sectional observation nor in-hole breakage occurred, and an excellent effect was achieved.
  In Example 2, the phenomenon that the plating film thickness in the hole became thinner as the hole diameter became smaller occurred, but it was judged that there was no problem.
[0050]
  In Comparative Example 1, when the hole diameter is small, it is difficult to adjust the via opening diameter, and the via becomes large. Specifically, the target of 40 μmφ is 50 μmφ. It was imagined that the etching solution was likely to be accumulated in the opening during the via etching, and the etching progressed. In addition, since the number of processes is increased, the production efficiency is lowered.
[0051]
  In Comparative Example 2, bumps were formed in the vicinity of the vias due to the scattering of copper by batch irradiation, but as a result of not performing the polishing process, bumps were formed around the vias in any via diameter samples. Further, in the samples of 60 μmφ and 40 μmφ, the plating growth in the vias was not uniform, voids were formed in the vias, and disconnection occurred after being placed in the pressure cooker tester.
[0052]
  In Comparative Example 3, a result equivalent to that of the example of the present invention was obtained in the evaluation. However, the electroless copper plating requires a long time, the line speed has to be slowed, and the production efficiency is low.
[0053]
【The invention's effect】
  According to the invention of claim 1, at least (a) a base material having a first conductor layer and a second conductor layer on both sides of a long insulating film is used, and at both ends of the insulating film, A step of forming a plurality of sprocket holes along the direction, (b) a laser from one surface of the insulating film-Irradiating light, penetrating the first conductor layer and the insulating film, and forming a conduction hole having a diameter of 120 μm or less reaching the second conductor layer, (c) surfaces of the first conductor layer and the second conductor layer (D) The wall surface of the hole for conduction is selected from palladium fine particles, carbon, and a conductive polymer.Thin film conductor(E) a step of forming a conductive layer at least in the hole for conduction by electrolytic plating, (f) a step of etching the first conductor layer and the second conductor layer to form a wiring layer, g) Since it consists of each process of forming a solder resist layer on the first conductor layer and the second conductor layer, the copper foil etching process is unnecessary before laser processing, such as electroless plating and sputtering. Therefore, it is not necessary to perform a process that requires a long time, and the equipment can be made small. Therefore, it is possible to manufacture a film carrier that has very high efficiency and excellent electrical reliability.
  In addition, the fact that the equipment can be reduced not only reduces the equipment cost, but also shortens the time for passing the equipment, so that the production efficiency is increased. And it is the outstanding manufacturing method which enables manufacture by reel to reel.
[0054]
  According to the invention of claim 2, in the film carrier manufacturing method of claim 1, as the step (e), a step of forming a conductive layer on the inner wall of the hole for conduction by electrolytic plating, Since the process of filling the hole with resin is performed, the resin reinforces the conductive layer on the inner wall of the hole for conduction, and thus it is possible to manufacture a film carrier with high electrical reliability.
[0055]
  And according to invention of Claim 3, in the manufacturing method of the film carrier of Claim 1, in order to bury the inside of a hole for conduction | electrical_connection by the electroplating of the said (e) process, the connection reliability in the hole for conduction | electrical_connection is carried out. Therefore, it is possible to manufacture a film carrier having high electrical reliability.
[0056]
  According to a fourth aspect of the present invention, in the film carrier manufacturing method according to any one of the first to third aspects, the steps (a) to (g) are performed on a reel-to-reel basis. It is possible to manufacture a film carrier with extremely high manufacturing efficiency and high electrical reliability.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a film carrier according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along line 2-2 in the same embodiment.
FIG. 3 is a process cross-sectional view for explaining a film carrier manufacturing method according to the embodiment;
FIG. 4 is a process sectional view for explaining a film carrier manufacturing method according to the embodiment;
[Explanation of symbols]
  10 ... Film carrier
  11 ... Insulating film
  12 ... Adhesive layer
  13 ... Sprocket hole
  14 ... conduction hole
  15...Thin film conductor
  15b...Conductive layer
  16...Pad electrode
  17a, b ... copper foil
  18 ... Wiring pattern
  19 ... Solder resist layer
  20 ...Photo (made of photosensitive material)Solder resist layer
  21 ... Solder ball mounting hole
  30 ... Copper protrusion
  40 ... resist layer
  50 ・ ・ ・ Polyimide with copper foilthe film
  D ... Desmear liquid
  L ... Laser light
  UV ... exposure light

Claims (4)

The manufacturing method of the film carrier characterized by including the following process (a)-(g) at least.
(A) The process which uses the base material which has a 1st conductor layer and a 2nd conductor layer on both surfaces of an elongate insulating film, and forms a some sprocket hole along a longitudinal direction at the both ends of the said insulating film .
(B) said insulating one of the laser over light from the surface to the irradiation of the film, through the insulating film and the first conductive layer, forming a second conductive layer to reach the diameter 120μm or less conducting holes.
(C) A step of polishing and flattening the surfaces of the first conductor layer and the second conductor layer.
(D) A step of attaching a thin film conductor selected from palladium fine particles, carbon, and a conductive polymer to the wall surface of the hole for conduction.
(E) A step of forming a conductive layer at least in the hole for conduction by electrolytic plating.
(F) A step of etching the first conductor layer and the second conductor layer to form a wiring layer.
(G) A step of forming a solder resist layer on the first conductor layer and the second conductor layer.   2. The film carrier according to claim 1, wherein the step (e) includes a step of forming a conductive layer on the inner wall of the hole for conduction by electrolytic plating and a step of filling the inside of the hole for conduction with a resin. Method.   The film carrier manufacturing method according to claim 1, wherein the hole for conduction is filled by electrolytic plating in the step (e).   The method of manufacturing a film carrier according to any one of claims 1 to 3, wherein the steps (a) to (g) are performed by a reel-to-reel method.

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