JP2007053503A - Antenna and itys manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high performance print flat plate antenna which is high in precision, low in cost, excellent in productivity and applicable to a shorter wavelength technology, and to provide its manufacturing method. <P>SOLUTION: The antenna comprising an insulation board and a conductor lines formed on the insulation board and the manufacturing method thereof are provided, and the manufacturing method of the antenna characterized in to include: a process of applying surface treatment to the surface of the insulation board including a layer containing a polyimide resin with a siloxane structure at least on the surface by means of alkali; and a process of forming the conductor lines by electroless deposition process can provide the high accuracy print antenna wherein high adhesiveness between the insulating resin material and the electroless plating film is realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an antenna for mobile communication used in a mobile phone, an RFIC tag, or an automobile phone, and a manufacturing method thereof, and more particularly, to a method of forming a conductor line of an antenna and a method of connecting to an electronic circuit.

In recent years, communication systems using radio have been widely used, and the development of communication systems using radio waves in a high frequency region where there is a large amount of information has been remarkable. In such a communication system, a planar antenna is suitable as an input / output device for a short-wavelength wireless system. For example, it is expected to be applied in a microwave or millimeter wave region such as a collision prevention radar in a wireless LAN or an automobile. Has been.
The size of the antenna in such a communication system needs to be made in accordance with the wavelength of the electric (magnetic) wave. When the wavelength of the transmission signal to be received is λ, the length of λ is λ. It is determined to be equal to the length of the conductor line. For example, in the case of an RFIC tag, the use of radio waves in the vicinity of 900 MHz is currently being studied. In this case, an antenna having a length of about 80 cm is required. In the future, the wavelength of information communication elements will be further shortened. However, as the wavelength is shortened, the antenna as the input / output device is also reduced in size, and the dimensional accuracy of the antenna becomes stricter accordingly. Therefore, microfabrication technology is required for forming the conductive line of the antenna (Patent Documents 1 to 4).
A conventional printed antenna used for such a purpose includes an insulating substrate and a conductor line formed on the upper surface of the insulating substrate. The insulating substrate is, for example, a mother substrate of a simple mobile phone. A transmitting / receiving circuit is formed. Such a printed antenna is generally manufactured using a laminated board with a metal foil, and is manufactured using a photoresist technique and a metal foil etching technique well known in the field of printed wiring boards. The

However, it has become difficult to provide a planar antenna that is highly accurate, inexpensive, excellent in productivity, and applicable to shorter wavelengths in such a conventional manufacturing method. The method of forming a conductor line (for example, slot pattern or patch pattern) of an antenna using the etching technique as described above has a limitation that the precision of microfabrication is limited and cannot be produced in large quantities.
For example, the dimensional accuracy in millimeter waves requires at least 1% of the wavelength, and the accuracy of several tens of μm is required at 50 GHz. In addition, when a large number of resonance slots and patch patterns are arranged in an array, it is required to control the dimensional accuracy more strictly in order to maintain the directivity. Currently, an inexpensive and practical method for manufacturing an antenna has not been realized for such a demand.

  The electroless plating method is a method in which a reducing agent is placed in an aqueous solution of metal salt without using electric energy, and the metal is deposited on the substrate by the reducing action resulting from its decomposition, forming a highly accurate conductive line. Since it has the feature that it can be done, it is considered to be one of the most promising methods for manufacturing antenna conductor lines. However, when forming a circuit by applying an electroless plating method to the production of a printed wiring board or the formation of a conductor line of an antenna, the problem is that the adhesiveness between the electroless plating layer and the insulating material is low.

As a general method for solving the above problems, the surface of the insulating resin material is roughened by various methods, and the adhesion to the electroless plating film is obtained by a so-called anchor effect. However, when the surface roughness is small, the adhesion between the electroless plating layer and the resin material is low, and there is a problem that fine wiring cannot be formed when a large roughening is performed (Patent Document 5).
As a means for solving such a problem, a polyimide precursor mainly composed of an aromatic tetracarboxylic dianhydride and a siloxane diamine is applied to or applied to at least one surface of a heat-resistant resin film. A resin-attached metal foil in which a polyimide precursor is entirely imidized and a metal plating layer is formed thereon and a method for producing a flexible wiring board using the same are disclosed (Patent Document 6). However, this process requires a complicated heat treatment step for the precursor, and the adhesion between the formed metal plating layer and the substrate is not sufficient. Further, attempts to manufacture an antenna using such a process have been made. It wasn't.
JP-A-10-209745 JP 05-167330 A JP2003-115718A JP2004-15833 JP2000-198907 JP 2002-264255 A

  An object of the present invention is to provide a high-performance antenna that is highly accurate, inexpensive, excellent in productivity, and applicable to shorter wavelengths. In particular, we will develop a resin material that can provide high adhesion between an insulating resin material and an electroless plating film even when the surface roughness is low, and solve the above problems by applying it to the manufacture of high-performance antennas. It is what.

As a result of intensive studies in view of the above problems, the present inventors have found that the following problems can be solved by developing and using the following plating materials. That is,
The present invention is an antenna comprising an insulating substrate and a conductor line formed on the insulating substrate, and includes a layer containing a polyimide resin having a siloxane structure on at least a surface of the insulating substrate, and the conductor line is at least An antenna characterized by being manufactured using an electroless plating process.
Moreover, it is preferable that the polyimide resin which has the said siloxane structure is a polyimide resin which consists of an acid dianhydride component and the diamine component containing the diamine represented by following General formula (1).

（式中、ｇは１以上の整数を表す。また、Ｒ¹¹及びＲ²²は、それぞれ同一、または異なっていてよく、アルキレン基またはフェニレン基を表す。Ｒ³³、Ｒ⁴⁴、Ｒ⁵⁵、Ｒ⁶⁶は、それぞれ同一、または異なっていてよく、アルキル基、フェニル基またはフェノキシ基を表す。）
前記絶縁基板上に形成された導体線路の少なくとも一つの端子が、前記導体線路が形成されている面とは異なる前記絶縁基板の面に形成された電気回路と、前記絶縁基板に形成された貫通孔を通して電気的に接続されている事が好ましい。

(In the formula, g represents an integer of 1 or more. R ¹¹ and R ²² may be the same or different and each represents an alkylene group or a phenylene group. R ³³ , R ⁴⁴ , R ⁵⁵ , R ⁶⁶ Each may be the same or different and each represents an alkyl group, a phenyl group or a phenoxy group.)
At least one terminal of a conductor line formed on the insulating substrate has an electric circuit formed on a surface of the insulating substrate different from a surface on which the conductor line is formed, and a through formed in the insulating substrate It is preferable to be electrically connected through the hole.

Furthermore, it is preferable that an electrical connection line connecting the terminal and the electric circuit through the through hole is formed by a process including at least an electroless plating process.
The present invention also provides an antenna manufacturing method comprising an insulating substrate and a conductor line formed on the insulating substrate, wherein at least the surface of the insulating substrate including a layer containing a polyimide resin having a siloxane structure on the surface is alkalinized. And a process for forming the conductor line by an electroless plating process.
Moreover, it is preferable that the polyimide resin which has the said siloxane structure is a polyimide resin which consists of an acid dianhydride component and the diamine component containing the diamine represented by following General formula (1).

（式中、ｇは１以上の整数を表す。また、Ｒ¹¹及びＲ²²は、それぞれ同一、または異なっていてよく、アルキレン基またはフェニレン基を表す。Ｒ³³、Ｒ⁴⁴、Ｒ⁵⁵、Ｒ⁶⁶は、それぞれ同一、または異なっていてよく、アルキル基、フェニル基またはフェノキシ基を表す。）
さらに前記絶縁基板上に形成された導体線路の少なくとも一つの端子と、前記導体線路が形成されている面とは異なる前記絶縁基板の面に形成された電気回路を、前記絶縁基板に形成された貫通孔を通して電気的に接続するプロセスを含む事が好ましい。
さらに前記電気的に接続するプロセスが、少なくとも無電解めっき工程を含むプロセスであることが好ましい。

(In the formula, g represents an integer of 1 or more. R ¹¹ and R ²² may be the same or different and each represents an alkylene group or a phenylene group. R ³³ , R ⁴⁴ , R ⁵⁵ , R ⁶⁶ Each may be the same or different and each represents an alkyl group, a phenyl group or a phenoxy group.)
Further, at least one terminal of the conductor line formed on the insulating substrate and an electric circuit formed on the surface of the insulating substrate different from the surface on which the conductor line is formed are formed on the insulating substrate. It is preferable to include the process of electrically connecting through a through-hole.
Furthermore, it is preferable that the electrical connection process is a process including at least an electroless plating step.

By using the insulating substrate of the present invention, a fine conductor line of an antenna can be accurately produced with a strong adhesion on a substrate with extremely small surface irregularities. In addition, the fine conductor line of the antenna can be accurately produced with a strong adhesive force on a substrate with extremely small surface irregularities by the method of the present invention. Furthermore, according to the method of the present invention, it is possible to form a transmission / reception device electronic circuit and a ground wire on a surface different from the surface on which the antenna conductor line is formed, and it is possible to reduce the size of the device.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following descriptions.
<Polyimide resin of the present invention>
First, the polyimide resin having a siloxane structure used in the present invention will be described. A polyimide resin is obtained by reacting an acid dianhydride component and a diamine component. Hereinafter, the acid dianhydride component will be described.

  The acid dianhydride component is not particularly limited, and pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetra Carboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 3, 3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl Propanic acid dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, p-phenylenediphthalic anhydride Such Aromatic tetracarboxylic dianhydride, 4,4′-hexafluoroisopropylidenediphthalic anhydride, 4,4′-oxydiphthalic anhydride, 3,4′-oxydiphthalic anhydride, 3,3′-oxydiphthalate Acid anhydride, 4,4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic anhydride), 4,4′-hydroquinonebis (phthalic anhydride), 2,2-bis (4-hydroxyphenyl) ) Propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 1,2-ethylenebis (trimellitic acid monoester anhydride), p-phenylenebis (trimellitic acid monoester anhydride) And the like. These may be used alone or in combination of two or more.

  Subsequently, the diamine component will be described. In this invention, it is preferable that the diamine component represented by following General formula (1) is included as a diamine component.

（式中、ｇは１以上の整数を表す。また、Ｒ¹¹及びＲ²²は、それぞれ同一、または異なっていてよく、アルキレン基またはフェニレン基を表す。Ｒ³³、Ｒ⁴⁴、Ｒ⁵⁵、Ｒ⁶⁶は、それぞれ同一、または異なっていてよく、アルキル基、フェニル基またはフェノキシ基を表す。）
一般式（１）で表されるジアミン成分を用いることにより、得られるポリイミド樹脂は、無電解めっき層と強固に接着するという特徴を有するようになる。

(In the formula, g represents an integer of 1 or more. R ¹¹ and R ²² may be the same or different and each represents an alkylene group or a phenylene group. R ³³ , R ⁴⁴ , R ⁵⁵ , R ⁶⁶ Each may be the same or different and each represents an alkyl group, a phenyl group or a phenoxy group.)
By using the diamine component represented by the general formula (1), the obtained polyimide resin has a characteristic of being firmly bonded to the electroless plating layer.

  The diamine represented by the general formula (1) is 1,1,3,3-tetramethyl-1,3-bis (4-aminophenyl) disiloxane, 1,1,3,3-tetraphenoxy. -1,3-bis (4-aminoethyl) disiloxane, 1,1,3,3,5,5-hexamethyl-1,5-bis (4-aminophenyl) trisiloxane, 1,1,3,3 , -Tetraphenyl-1,3-bis (2-aminophenyl) disiloxane, 1,1,3,3-tetraphenyl-1,3-bis (3-aminopropyl) disiloxane, 1,1,5 , 5, -tetraphenyl-3,3-dimethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,5,5, -tetraphenyl-3,3-dimethoxy-1,5-bis (3-Aminobutyl) trisiloxane, 1,1,5,5,- Traphenyl-3,3-dimethoxy-1,5-bis (3-aminopentyl) trisiloxane, 1,1,3,3, -tetramethyl-1,3-bis (2-aminoethyl) disiloxane, , 1,3,3-Tetramethyl-1,3-bis (3-aminopropyl) disiloxane, 1,1,3,3-tetramethyl-1,3-bis (4-aminobutyl) disiloxane 1,3-dimethyl-1,3-dimethoxy-1,3-bis (4-aminobutyl) disiloxane, 1,1,5,5, -tetramethyl-3,3-dimethoxy-1,5-bis (2-Aminoethyl) trisiloxane, 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5-bis (4-aminobutyl) trisiloxane, 1,1,5,5,- Tetramethyl-3,3-dimethoxy-1,5-bis (5- Aminopentyl) trisiloxane, 1,1,3,3,5,5-hexamethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,3,3,5,5-hexaethyl-1, Examples include 5-bis (3-aminopropyl) trisiloxane, 1,1,3,3,5,5-hexapropyl-1,5-bis (3-aminopropyl) trisiloxane, and the like. In addition, as relatively easily available diamines represented by the general formula (1), KF-8010, X-22-161A, X-22-161B, X-22-1660B-3 manufactured by Shin-Etsu Chemical Co., Ltd. , KF-8008, KF-8012, X-22-9362, and the like. The said diamine may be used independently and may mix 2 or more types.

  In addition, for the purpose of improving heat resistance and moisture resistance, it is also possible to use a combination of the above-described diamine and another diamine. As the other diamine component, any diamine can be used, and m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis (3-amino). Phenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, Bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3, 3'-diaminodiphenylmethane, 3,4'-di Minodiphenylmethane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (Aminophenoxy) phenyl] sulfoxide, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenylthioether, 3,4′-diamino Diphenylthioether, 3,3'-diaminodiphenylthioether, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfur 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzanilide, 3,4'-diaminobenzanilide, 3,3'-diaminobenzanilide, 4, 4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) ) Phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenyl) Enoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [3- (3-Aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3 3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4′-bis (4-aminophenoxy) benzene, 4, 4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3- Minophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-Aminophenoxy) benzoyl] benzene, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] ben Phenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4 -Bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 3,3′- Examples thereof include dihydroxy-4,4′-diaminobiphenyl.

  Here, 5-98 mol% is preferable with respect to all the diamine components, and, as for the diamine represented by General formula (1), More preferably, it is 8-95 mol%.

  When the diamine represented by General formula (1) is lower than 5 mol% with respect to all the diamine components, the obtained polyimide resin may impair the adhesiveness with the electroless plating layer. Moreover, when the diamine represented by General formula (1) is higher than 98 mol% with respect to all the diamine components, the polyimide resin obtained may have adhesiveness. In this case, foreign matters such as dust may adhere due to adhesiveness, and plating defects due to foreign matters may occur during electroless plating.

  The polyimide is obtained by dehydrating and ring-closing the corresponding precursor polyamic acid polymer. The polyamic acid polymer is obtained by reacting an acid dianhydride component and a diamine component in substantially equimolar amounts.

  A typical procedure for the reaction is a method in which one or more diamine components are dissolved or dispersed in an organic polar solvent, and then one or more acid dianhydride components are added to obtain a polyamic acid solution. The order of addition of each monomer is not particularly limited, and the acid dianhydride component may be added to the organic polar solvent in advance, and the diamine component may be added to form a polyamic acid polymer solution, or the diamine component may be added to the organic polar solvent. A suitable amount of the acid dianhydride component may be added first, and then an excess amount of the dianhydride component may be added, and a diamine component corresponding to the excess amount may be added to form a polyamic acid polymer solution. There are various other addition methods known to those skilled in the art. The term “dissolved” as used herein refers to a state in which the solute is uniformly dissolved or dispersed in the solvent in addition to the case where the solvent completely dissolves the solute. Including cases. The reaction time and reaction temperature are not particularly limited.

  Examples of the organic polar solvent used in the polyamic acid polymerization reaction include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, N, N- Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol, Examples thereof include phenol solvents such as halogenated phenol and catechol, hexamethylphosphoramide, and γ-butyrolactone. Further, if necessary, these organic polar solvents can be used in combination with an aromatic hydrocarbon such as xylene or toluene.

  The polyamic acid solution obtained by the above method is dehydrated and cyclized by a thermal or chemical method to obtain a polyimide, and a thermal method in which the polyamic acid solution is subjected to heat treatment for dehydration, a chemical method for dehydration using a dehydrating agent. Any of these can be used. Moreover, the method of imidating by heating under reduced pressure can also be used. Each method will be described below.

  As a method of thermally dehydrating and cyclizing, a method of evaporating the solvent at the same time that the polyamic acid solution is subjected to an imidation reaction by heat treatment can be exemplified. By this method, a solid polyimide resin can be obtained. The heating conditions are not particularly limited, but it is preferably performed at a temperature of 200 ° C. or lower for a time range of 1 second to 200 minutes.

  Further, as a method of chemically dehydrating and cyclizing, a method of causing a dehydration reaction by adding a dehydrating agent and a catalyst having a stoichiometric amount or more to the polyamic acid solution and evaporating the organic solvent can be exemplified. Thereby, a solid polyimide resin can be obtained. Examples of the dehydrating agent include aliphatic acid anhydrides such as acetic anhydride and aromatic acid anhydrides such as benzoic anhydride. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic rings such as pyridine, α-picoline, β-picoline, γ-picoline, and isoquinoline. And tertiary amines of the formula. The conditions for chemically dehydrating and cyclizing are preferably 100 ° C. or less, and the organic solvent is preferably evaporated at a temperature of 200 ° C. or less for a period of about 5 minutes to 120 minutes.

  In addition, as another method for obtaining a polyimide resin, there is a method in which the solvent is not evaporated in the thermal or chemical dehydration and ring closure method. Specifically, a polyimide solution obtained by performing thermal imidization treatment or chemical imidization treatment with a dehydrating agent is put into a poor solvent, a polyimide resin is precipitated, unreacted monomers are removed, and purification and drying are performed. And obtaining a solid polyimide resin. As the poor solvent, a solvent that is well mixed with the solvent but is difficult to dissolve polyimide is selected. Illustrative examples include, but are not limited to, acetone, methanol, ethanol, isopropanol, benzene, methyl cellosolve, methyl ethyl ketone, and the like.

  Next, although it is the method of imidating by heating under reduced pressure, according to this imidization method, water generated by imidization can be actively removed out of the system, so that hydrolysis of polyamic acid is suppressed. And a high molecular weight polyimide is obtained. In addition, according to this method, one-sided or both-side ring-opened products existing as impurities in the raw acid dianhydride are closed again, so that a further improvement in molecular weight can be expected.

  The heating condition of the method of heating imidization under reduced pressure is preferably 80 to 400 ° C., more preferably 100 ° C. or more, more preferably 120 ° C. or more, in which imidization is efficiently performed and water is efficiently removed. is there. The maximum temperature is preferably equal to or lower than the thermal decomposition temperature of the target polyimide, and a normal imidation completion temperature, that is, about 250 to 350 ° C. is usually applied.

  The condition for the pressure to be reduced is preferably smaller, but specifically, 9 × 10 4 to 1 × 10 2 Pa, preferably 8 × 10 4 to 1 × 10 2 Pa, more preferably 7 × 10 4 to 1 × 10 2 Pa.

  The polyimide resin has been described above. As an example of a polyimide resin containing a siloxane structure that is relatively easily available and can be used for the plating material of the present invention, X-22-8917 manufactured by Shin-Etsu Chemical Co., Ltd., X -22-8904, X-22-8951, X-22-8756, X-22-8984, X-22-8985, and the like. These are polyimide solutions.

<Insulating substrate structure>
The insulating substrate of the present invention has a surface for performing electroless plating, and the surface contains a polyimide resin having a siloxane structure (hereinafter referred to as surface A). By containing such a polyimide resin, high adhesive strength with the electroless plating film can be obtained even when the surface roughness is small. That is, in the process of the present invention, a strong electroless plating layer can be formed without performing surface roughening, and therefore a fine antenna circuit can be formed with high accuracy.
In order to form the polyimide resin layer (surface A) having a siloxane structure of the present invention, a solution containing a polyimide resin is preferably used. A surface A layer is formed on the surface of the substrate to be plated using this solution, and then electroless plating is performed. The A layer serves as an interlayer adhesive and serves to firmly bond the substrate and the electroless plating. The A layer has both adhesiveness and heat resistance, and even when the surface roughness is small, the electroless plating layer can be formed firmly, so that it can be suitably used for forming an antenna conductor line.
A method of forming a surface layer using a polyimide precursor and then imidizing by heating on the substrate surface is also conceivable, but this method requires a complicated heat treatment step, and further, due to heat treatment with insufficient imidization. In many cases, sufficient adhesive strength cannot be obtained due to the mechanical strength of the resin layer considered, generated gas, etc., and it may not be suitable for the purpose of the present invention.

As long as the surface A containing the said polyimide resin is contained, the insulation board | substrate of this invention may be the material and form which consist of what kind of structure.
That is, the surface A containing the polyimide resin may be a material composed only of the polyimide resin, or may be a material in which the polyimide resin and another polymer are compatible. Specifically, in order to improve various properties such as adhesion to the substrate, heat resistance and moisture resistance, it is possible to contain other components in addition to the above polyimide resin. As other components, resins such as thermoplastic resins and thermosetting resins can be used as appropriate.

  Examples of the thermoplastic resin include a polysulfone resin, a polyethersulfone resin, a polyphenylene ether resin, a phenoxy resin, an acid dianhydride component, and a thermoplastic polyimide resin. These may be used alone or in appropriate combination. Can do.

  Thermosetting resins include bismaleimide resin, bisallyl nadiimide resin, phenol resin, cyanate resin, epoxy resin, acrylic resin, methacrylic resin, triazine resin, hydrosilyl cured resin, allyl cured resin, unsaturated polyester resin, etc. These can be used alone or in appropriate combination. In addition to the thermosetting resin, a side chain reactive group type thermosetting having a reactive group such as an epoxy group, an allyl group, a vinyl group, an alkoxysilyl group or a hydrosilyl group at the side chain or terminal of the polymer chain. It is also possible to use a functional polymer.

  For the purpose of further improving the adhesion with the electroless plating layer, various additives may be added to the polymer material and may be present on the surface of the polymer material by a method such as coating. Specific examples include organic thiol compounds, but are not limited thereto. Furthermore, various organic fillers and inorganic fillers can be added.

  It is important to combine the other components described above within a range that does not adversely affect the formation of the wiring and within a range that does not deteriorate the adhesion with the electroless plating layer. The thickness of the surface layer of the present invention is desirably 10 mm or more.

  Next, the structure of the insulating substrate of the present invention will be described. The material and form having any structure means that a surface A layer (hereinafter referred to as A layer) may be formed on some substrate surface.

  Here, the substrate refers to various polymer films (polyimide resin, epoxy resin, polyester resin, etc., which may contain additives such as glass cloth and flame retardant) and ceramic substrates. A two-layer structure with an A layer (A layer / substrate) or a three-layer structure (A layer / substrate / A layer) in which an A layer is formed on both surfaces of an insulating substrate may be used. Moreover, the structure of A layer / board | substrate / B layer, A layer / B layer / board | substrate etc. may be sufficient, and the further multilayered structure may be sufficient. The purpose of describing the B layer here means that, for example, the B layer has a function of bonding with another insulating substrate or bonding between the A layer and the substrate, and embedding a circuit such as a prepreg and bonding with the substrate. It means that it is a layer that plays the role of.

  Hereinafter, the case where the B layer is the prepreg will be described in detail. When the B layer is laminated on the surface having the formed circuit, excellent workability is required so that the B layer flows between the circuits and the circuit can be embedded. In general, the thermosetting resin is excellent in the processability, and the B layer preferably contains a thermosetting resin. This thermosetting resin composition includes epoxy resin, phenol resin, thermosetting polyimide resin, cyanate ester resin, hydrosilyl cured resin, bismaleimide resin, bisallyl nadiimide resin, acrylic resin, methacrylic resin, allyl resin, Thermosetting resin such as saturated polyester resin; side chain reactive group type thermosetting polymer having reactive groups such as allyl group, vinyl group, alkoxysilyl group, hydrosilyl group at the side chain or terminal of polymer chain It can be applied as a thermosetting resin composition in combination with an appropriate thermosetting agent and a curing catalyst. It is also possible to preferably add a thermoplastic polymer to these thermosetting resin compositions. For example, a thermosetting resin composition containing an epoxy resin and a phenoxy resin, or a heat containing an epoxy resin and a thermoplastic polyimide resin. A curable resin composition, a thermosetting resin composition containing a cyanate resin and a thermoplastic polyimide resin, and the like can be preferably implemented. Among these, a thermosetting resin composition containing an epoxy resin and a thermoplastic polyimide resin excellent in various property balances is most preferable. In addition, various fillers can be combined for low thermal expansion.

<Electroless plating>
Examples of the electroless plating formed on the surface A of the plating material of the present invention include electroless copper plating, electroless nickel plating, electroless gold plating, electroless silver plating, and electroless tin plating. However, from the viewpoint of electrical characteristics such as industrial viewpoint and migration resistance, electroless copper plating and electroless nickel plating are preferable, and electroless copper plating is particularly preferable.
In the process of applying electroless plating to the surface A of the present invention, it is preferable to preliminarily treat the surface A with alkali in order to achieve strong adhesion. As alkali treatment here, the same prescription as the desmear process performed after via-hole formation in the build-up wiring board formation process can be used. The typical desmear process conditions preferably used for this purpose will be described in Examples.
Moreover, it is also possible to heat-process after forming an electroless-plating layer in order to improve the adhesiveness of the surface A layer and an electroless-plating layer.
This electroless plating process is preferably formed by a process known as a semi-additive process, which is combined with a photoresist such as a liquid resist or a dry film resist, and an electroplating performed after the electroless plating. A fine line can be formed by combining the two. Note that typical electroless plating process conditions preferably used for this purpose are described in the Examples.
<Manufacturing method of antenna>
Next, although the example of the antenna manufacturing method of this invention is demonstrated, the method described here shows the example of a manufacturing method to the last, and is not limited to this.

FIG. 1 shows a first example of an antenna manufacturing method of the present invention using the above-described prepreg. First, a film is prepared in which a layer 11 (A layer) containing a polyimide resin having a siloxane structure is formed on the surface of a prepreg 12 as shown in FIG. The prepreg layer may be produced by laminating a plurality of prepregs. Next, as shown in FIG. 1B, this film is laminated and pressure-bonded onto the circuit board 14 by a method such as vacuum pressing or laminating. At the time of lamination, thermocompression treatment such as hot press treatment, vacuum press treatment, laminating treatment (heat laminating treatment), vacuum laminating treatment, hot roll laminating treatment, vacuum hot roll laminating treatment is performed. Among these, processing under vacuum, that is, vacuum press processing, vacuum laminating processing, and vacuum hot roll laminating processing can be preferably performed without voids between the circuits, and can be preferably performed. Note that the circuit 13 is already formed on the surface of the circuit board 14, and the prepreg 12 flows between the circuits 13 and is embedded therein.
Next, a resist layer is formed on the outer surface of the electroless plating layer by exposing and developing using a photoresist to cover a portion where the antenna line is not formed. Furthermore, as necessary, via holes are formed by drilling or laser processing as shown in FIG. Ordinary antennas require at least two terminals, a connection terminal to the electronic circuit and a ground terminal, and forming the conductor line of the antenna on a different surface from the electronic circuit (transmission / reception circuit) and the ground line is a small element. It is preferable for the preparation.

Next, as shown in FIG. 1D, the laminate is immersed in an electroless plating bath to form a thin metal layer on the surface by an electroless plating method. The metal layer is not particularly limited, but electroless plated copper is most preferably used. In addition, as a method of electroless metal plating, a known method including a desmear process and a catalyst supporting process is used. Next, using an electroless plating layer as a seed layer as necessary, an antenna line is formed and a via hole is filled using an electroplating method. The via may have either a filled via structure or a conformal via structure. In addition, since the antenna line does not require conductivity as in an ordinary electronic circuit, only a metal layer formed by electroless metal plating is often sufficient. In such cases, an electrolytic plating process is not necessary. Finally, the resist layer is dissolved and removed, and further an etching process is performed to obtain an element as shown in FIG.
Next, a second example of the antenna manufacturing method of the present invention will be described with reference to FIG.
First, a substrate (FIG. 2 (a)) having the A layer on both sides of the present invention is prepared. Next, a photoresist layer is formed on the outer surface of the substrate, and a resist pattern is formed by exposing and developing. Thereafter, a through hole (via hole) 24 is provided by drilling or laser processing as shown in FIG.
Next, the substrate is immersed in an electroless plating bath and plated to form a metal plating layer (electroless plating layer) 25 as shown in FIG. Next, using the electroless plating layer as a seed layer, an antenna line is formed and a via hole is filled using an electroplating method. Finally, by dissolving and removing the resist, an element having an antenna line on the front surface and an electronic circuit (transmission / transmission circuit) and a ground line on the back surface is completed as shown in FIG.
Next, a third example of the antenna manufacturing method of the present invention will be described with reference to FIG.
Here, reference numeral 31 in FIG. 3A denotes an insulating substrate, which is an insulating substrate such as a ceramic substrate, for example, and through holes (via holes) 32 are formed in the insulating substrate as necessary. First, a photoresist layer is formed on the surface of the insulating substrate, and a resist layer 33 that covers a portion where the antenna line is not formed is formed by exposing and developing. Next, the layer 34 containing the polyimide resin having the siloxane structure of the present invention is formed on the insulating substrate as shown in FIG. 3C by printing or dipping in a solution. Next, as shown in FIG. 3D, the surface of the layer 32 is subjected to electroless plating to form a metal layer 35. Further, if necessary, an electrolytic plating layer 36 is formed, and finally the photoresist layer is dissolved and removed to complete the antenna element as shown in FIG.
Although an example of forming a fine line using a photoresist has been described here, the A layer of the present invention is directly patterned on a substrate by a method such as printing without using a photoresist, and electroless plating is performed thereon. The method is fine.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to this. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention.
<Synthesis>
First, it describes about the synthesis | combination of the polyimide resin of this invention used in the Example.
[Polyimide resin synthesis example 1]
In a glass flask having a capacity of 2000 ml, 62 g (0.075 mol) of KF8010 manufactured by Shin-Etsu Chemical Co., Ltd., 15 g (0.075 mol) of 4,4′-diaminodiphenyl ether, N, N-dimethylformamide (hereinafter referred to as DMF) Is added, dissolved with stirring, and 78 g (0.15 mol) of 4,4 ′-(4,4′-isopropylidenediphenoxy) bisphthalic anhydride is added and stirred for about 1 hour to obtain a solid content concentration A DMF solution of 30% polyamic acid was obtained. The polyamic acid solution was placed in a Teflon (registered trademark) -coated vat and heated in a vacuum oven at 200 ° C. for 120 minutes under reduced pressure at 665 Pa to obtain polyimide resin 1.
[Polyimide resin synthesis example 2]
In a glass flask with a capacity of 2000 ml, 86 g (0.10 mol) of KF8010 manufactured by Shin-Etsu Chemical Co., Ltd., 9 g (0.05 mol) of 4,4′-diaminodiphenyl ether, N, N-dimethylformamide (hereinafter referred to as DMF) Is added, dissolved with stirring, and 78 g (0.15 mol) of 4,4 ′-(4,4′-isopropylidenediphenoxy) bisphthalic anhydride is added and stirred for about 1 hour to obtain a solid content concentration A DMF solution of 30% polyamic acid was obtained. The polyamic acid solution was placed in a Teflon (registered trademark) -coated vat and heated in a vacuum oven at 200 ° C. for 120 minutes under reduced pressure at 665 Pa to obtain polyimide resin 2.
[Polyimide resin synthesis example 3]
123 g (0.15 mol) of KF8010 manufactured by Shin-Etsu Chemical Co., Ltd. and N, N-dimethylformamide (hereinafter referred to as DMF) are charged into a glass flask having a volume of 2000 ml and dissolved while stirring. 78 g (0.15 mol) of '-(4,4'-isopropylidenediphenoxy) bisphthalic anhydride was added and stirred for about 1 hour to obtain a DMF solution of polyamic acid with a solid content concentration of 30%. The polyamic acid solution was placed in a vat coated with Teflon (registered trademark) and heated under reduced pressure at 200 ° C. for 120 minutes at 665 Pa in a vacuum oven to obtain a thermoplastic polyimide resin 3.
[Polyimide resin synthesis example 4]
In a glass flask having a capacity of 2000 ml, 41 g (0.143 mol) of 1,3-bis (3-aminophenoxy) benzene and 1.6 g (0.007 mol) of 3,3′-dihydroxy-4,4′-diaminobiphenyl were added. DMF was added and dissolved while stirring, and 78 g (0.15 mol) of 4,4 ′-(4,4′-isopropylidenediphenoxy) bisphthalic anhydride was added and stirred for about 1 hour. A DMF solution of 30% polyamic acid was obtained. The polyamic acid solution was placed in a Teflon (registered trademark) -coated vat and heated under reduced pressure at 200 ° C. for 180 minutes at 665 Pa in a vacuum oven to obtain polyimide resin 4.
[Solution Preparation Example 1]
The polyimide resin 1 was dissolved in dioxolane to obtain a solution (a). The solid content concentration was 15% by weight.
[Solution Formulation Example 2]
The polyimide resin 2 was dissolved in dioxolane to obtain a solution (b). The solid content concentration was 15% by weight.
[Solution Preparation Example 3]
The polyimide resin 3 was dissolved in dioxolane to obtain a solution (c). The solid content concentration was 15% by weight.
[Solution Preparation Example 4]
The polyimide resin 4 was dissolved in dioxolane to obtain a solution (d). The solid content concentration was 15% by weight.
[Solution Formulation Example 5]
90 g of the solution (c) and 10 g of the solution (d) were mixed to obtain a solution (e).
[Solution Preparation Example 6]
A polyimide silicone solution manufactured by Shin-Etsu Chemical Co., Ltd., X-22-8917 (solid content concentration 20% by weight, cyclohexanone solution) was used as solution (f).
[Solution Preparation Example 7]
Japan Epoxy Resin Co., Ltd. YX4000H 32.1g of biphenyl type epoxy resin, Wakayama Seika Kogyo Co., Ltd. bis [4- (3-aminophenoxy) phenyl] sulfone 17.9g, Shikoku Kasei Kogyo Co., Ltd. ) Epoxy curing agent, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine (0.2 g) was dissolved in dioxolane to obtain a solution (g). . 90 g of the solution (a) and 10 g of the solution (g) were mixed to obtain a solution (h).
[Formulation example 1 of layer B solution]
90 g of the solution (d), 10 g of the solution (g) and 6 g of silica (Admafine S0-C5, average particle size = 1.5 μm) manufactured by Tatsumori Co., Ltd. are mixed to obtain a layer B solution (j). It was.

<Plating method and adhesion evaluation>
The adhesion between the layer (A layer) containing the polyimide resin having a siloxane structure of the present invention and the electroless plated copper layer was evaluated as follows. First, the layer surface containing the polyimide resin was subjected to desmear treatment and electroless copper plating, and then an electroplated copper layer was formed on the electroless plated copper. Specific desmear treatment and electroless plating conditions are as shown in Tables 1 and 2, and the process conditions are in accordance with the electroless plating process of Atotech.

上記のプロセスで得られたメッキ層を、１８０℃、３０分の乾燥処理を行った後、ＪＰＣＡ−ＢＵ０１−１９９８（社団法人日本プリント回路工業会発行）に従い、常態、及びプレッシャークッカー試験（ＰＣＴ）後の接着強度を測定した。
常態接着強度：２５℃、５０％の雰囲気下、２４時間放置した後に測定した接着強度。
ＰＣＴ：１２１℃、１００％の雰囲気下、９６時間放置した後に測定した接着強度。
（実施例１〜６）
図２にその原理を記載した手法でアンテナを作成した。まず、２５μｍのポリイミドフィルム（商品名アピカルＮＰＩ、株式会社カネカ製）の両面に、前記溶液（ａ）、（ｂ）、（ｃ）、（ｅ）、（ｆ）、（ｇ）（それぞれ、順番に実施例１〜６に対応）を流延塗布し、熱風オーブンにて６０℃の温度で加熱乾燥させ、厚み５μｍの表面Ａを有するポリイミドフィルムを得た。
次に、基板の表面に液状感光性めっきレジスト（ＪＳＲ（株）社製、ＴＨＢ３２０Ｐ）をコーティングし、次いで高圧水銀灯を用いてマスク露光を行い、回路形成を及びビアホール形成を予定した部分を除く部分にライン／スペースが１０／１０のレジストパターンを形成した。続いて、必要な個所に炭酸ガスレーザーを用いてφ５０μｍのビアホールを形成し、さらに前記の方法で、デスミヤおよび無電解メッキを行い、図２（ｃ）にしめした様な銅被覆基板を作製した。次に、無電解銅めっき皮膜が露出する部分の表面に、電解メッキ法で銅皮膜を形成した。ポリイミドフィルムの電解銅めっきは１０％硫酸中で３０秒間予備洗浄し、次に室温中で４０分間メッキを行なった。電流密度は２Ａ／ｄｍ²であり、膜厚は１８μｍとした。
最後にアルカリ型の剥離液を用いてめっきレジストを剥離してアンテナ素子を得た。得られたアンテナ線路は設計値通りのライン／スペースを有しており、また、サイドエッチは無かった。回路パターンと各種表面Ａとの接着強度を表３にしめす。この結果から、アンテナ線路（回路）はいずれも強固に接着している事が分かった。また、実施例ではアンテナ線路長が１０ｃｍ、幅３０μｍとなるように試作をおこなったが、形成された線路の断面は３０×１８μｍの長方形であり、線路長の誤差はいずれも０．２％以下であった。

The plating layer obtained by the above process is dried at 180 ° C. for 30 minutes, and then subjected to normal and pressure cooker tests (PCT) according to JPCA-BU01-1998 (issued by the Japan Printed Circuits Association). The subsequent adhesive strength was measured.
Normal-state adhesive strength: Adhesive strength measured after standing for 24 hours in an atmosphere of 25 ° C. and 50%.
PCT: Adhesive strength measured after standing for 96 hours in an atmosphere of 121 ° C. and 100%.
(Examples 1-6)
An antenna was created by a technique whose principle is described in FIG. First, the solution (a), (b), (c), (e), (f), (g) (each in order) on both sides of a 25 μm polyimide film (trade name Apical NPI, manufactured by Kaneka Corporation) (Corresponding to Examples 1 to 6) were cast and dried in a hot air oven at a temperature of 60 ° C. to obtain a polyimide film having a surface A having a thickness of 5 μm.
Next, a liquid photosensitive plating resist (THB320P, manufactured by JSR Corporation) is coated on the surface of the substrate, then mask exposure is performed using a high-pressure mercury lamp, and portions other than the portions where circuit formation and via hole formation are planned are excluded. A resist pattern having a line / space of 10/10 was formed. Subsequently, a φ50 μm via hole was formed at a necessary location using a carbon dioxide laser, and desmearing and electroless plating were further performed by the above-described method to produce a copper-coated substrate as shown in FIG. . Next, a copper film was formed by electrolytic plating on the surface of the portion where the electroless copper plating film was exposed. The electrolytic copper plating of the polyimide film was pre-cleaned in 10% sulfuric acid for 30 seconds and then plated at room temperature for 40 minutes. The current density was 2 A / dm ² and the film thickness was 18 μm.
Finally, the plating resist was stripped using an alkaline stripping solution to obtain an antenna element. The obtained antenna line had a line / space as designed, and there was no side etch. Table 3 shows the adhesive strength between the circuit pattern and various surfaces A. From this result, it was found that all the antenna lines (circuits) were firmly bonded. In addition, in the example, the prototype was made so that the antenna line length was 10 cm and the width was 30 μm, but the cross section of the formed line was a rectangle of 30 × 18 μm, and the error of the line length was 0.2% or less in all cases. Met.

（比較例１）
１８μｍの厚さの銅箔付きポリイミドフィルム（２５μｍ）を用いてサブトラ法（エッチング）により同じアンテナ線路を形成した場合には、線路の断面は台形となった。その形は線路上面で平均幅１２μ、線路底面で平均幅３８μｍ、線路は平均１０μｍ程度のサイドの凹凸を有していた。また線路長の誤差は１．３％であった。
この事から本発明の手法により精密なアンテナ線路の形成が可能である事がわかった。

(Comparative Example 1)
When the same antenna line was formed by a sub-tra method (etching) using a 18 μm-thick polyimide film with a copper foil (25 μm), the cross section of the line became a trapezoid. The shape had side irregularities of an average width of 12 μm on the upper surface of the line, an average width of 38 μm on the bottom surface of the line, and an average of about 10 μm. The error of the line length was 1.3%.
From this, it was found that a precise antenna line can be formed by the method of the present invention.

(Examples 7 to 8)
An embodiment for manufacturing an antenna based on the process shown in FIG. 1 will be described. First, the solutions (a) and (b) (corresponding to Examples 7 to 8 in order) were cast and applied onto the surface of a polyethylene terephthalate film (trade name Therapy HP, manufactured by Toyo Metallizing Co., Ltd.) serving as a support. The film having a surface A having a thickness of 5 μm was obtained by heating and drying in a hot air oven at a temperature of 60 ° C. Subsequently, the solution (j) was cast and applied and dried in a hot air oven at 80 ° C., 100 ° C., 120 ° C., 150 ° C., and 170 ° C. for 1 minute each, and the combined thickness of both layers was 40 μm. A substrate film was obtained.

  The obtained film was vacuum-pressed (3 MPa, 180 ° C., 1 hour), and a circuit-formed glass epoxy substrate FR-4 (product number: MCL-E-67, manufactured by Hitachi Chemical Co., Ltd .; copper) The laminated body shown in FIG. 1B was manufactured by pressure-bonding onto a foil having a thickness of 50 μm and an overall thickness of 1.2 mm. Thereafter, photoresist formation and via hole formation were performed in the same manner as in Example 1, and then the antenna circuit was formed by performing electroless plating, electrolytic plating, and resist stripping, and the antenna and electronic circuit shown in FIG. The laminated body element was obtained. Table 4 shows the evaluation results of the adhesive strength between the antenna circuit and the substrate. From this result, it was found that all the antenna lines (circuits) were firmly bonded. In addition, in the example, the prototype was made so that the antenna line length was 10 cm and the width was 30 μm, but the formed line had a cross section as calculated, and the line length error was 0.2% or less. . From this fact, it was found that a precise antenna line can be formed by the method of the present invention.

（実施例９）
図３に示したプロセスに基づいてアンテナを製造する実施例について説明する。まず、セラミック基板（アルミナ基板）を準備し、その表面にドライフィルムレジスト（旭化成エレクトロニクス社製レジストフィルム、サンフォート）を圧着し、露光現像をおこなってトレジスト層を形成した。
次に、溶液（ａ）にさらにジオキソラン加えて固形分濃度が５％になるように調整し、その溶液中に上記セラミック基板を浸漬、引き上げを行い、さらに熱風オーブンにて６０℃の温度で加熱乾燥させ、平均厚み８μｍの層を形成した。次に、実施例１と同様の方法で、フォトレジスト形成、ビアホール形成を行い、さらに無電解メッキ、電解メッキ、レジスト剥離をおこなってアンテナ回路形成を行い、図３（ｅ）に示すアンテナと電子回路の積層体素子を得た。アンテナ回路の基板との接着強度の評価をおこなった結果、アンテナ線路と回路（アースパターンを含む）はセラミック基板と、常態強度７N／ｃｍ、PCT後の接着強度６N／ｃｍで強固に接着している事が分かった。実施例ではアンテナ線路長が１０ｃｍ、幅３０μｍとなるように試作をおこなったが、形成された線路の断面は３０×１８μｍの長方形であり、線路長の誤差は０．０４であり、上記実施例と同様の精密なアンテナ形成が可能である事が分かった。

Example 9
An embodiment for manufacturing an antenna based on the process shown in FIG. 3 will be described. First, a ceramic substrate (alumina substrate) was prepared, a dry film resist (resist film manufactured by Asahi Kasei Electronics Co., Ltd., Sunfort) was pressure-bonded to the surface, and exposure and development were performed to form a resist layer.
Next, dioxolane is further added to the solution (a) to adjust the solid concentration to 5%, the ceramic substrate is immersed in the solution, pulled up, and further heated at a temperature of 60 ° C. in a hot air oven. A layer having an average thickness of 8 μm was formed by drying. Next, in the same manner as in Example 1, photoresist formation and via hole formation were performed, and further, electroless plating, electrolytic plating, and resist removal were performed to form an antenna circuit. The antenna and the electron shown in FIG. A circuit laminate element was obtained. As a result of evaluating the adhesive strength between the antenna circuit and the substrate, the antenna line and the circuit (including the ground pattern) are firmly bonded to the ceramic substrate with a normal strength of 7 N / cm and an adhesive strength of 6 N / cm after PCT. I found out. In the example, the antenna line length was 10 cm and the width was 30 μm, but the cross section of the formed line was a 30 × 18 μm rectangle, and the line length error was 0.04. It was found that the same precise antenna formation as is possible.

First example of antenna manufacturing method of the present invention Second example of antenna manufacturing method of the present invention Third example of the antenna manufacturing method of the present invention

Explanation of symbols

11 Layer containing polyimide resin having siloxane structure 12 Insulating layer (prepreg)
13 Circuit 14 Circuit board 15 Photoresist 16 Via hole 17 Electroless plating layer 18 Electrolytic plating layer 21 Layer containing polyimide resin having siloxane structure 22 Insulating substrate 23 Photoresist 24 Via hole 25 Electroless plating layer 26 Electrolytic plating layer 31 Insulating layer 32 Via hole 33 Dry film resist 34 Layer containing polyimide resin having siloxane structure 35 Electroless plating layer 36 Electrolytic plating layer

Claims (8)

An antenna comprising an insulating substrate and a conductor line formed on the insulating substrate, the antenna substrate comprising a layer containing a polyimide resin having a siloxane structure on at least a surface of the insulating substrate, wherein the conductor line is at least an electroless plating process An antenna characterized by being made using The polyimide resin having the siloxane structure is a polyimide resin composed of an acid dianhydride component and a diamine component containing a diamine represented by the following general formula (1). antenna.

(In the formula, g represents an integer of 1 or more. R ¹¹ and R ²² may be the same or different and each represents an alkylene group or a phenylene group. R ³³ , R ⁴⁴ , R ⁵⁵ , R ⁶⁶ Each may be the same or different and each represents an alkyl group, a phenyl group or a phenoxy group.) At least one terminal of a conductor line formed on the insulating substrate has an electric circuit formed on a surface of the insulating substrate different from a surface on which the conductor line is formed, and a through formed in the insulating substrate The antenna according to claim 1, wherein the antenna is electrically connected through a hole.   The antenna according to claim 3, wherein an electrical connection line that connects the terminal and the electric circuit through the through hole is formed by a process including at least an electroless plating process. A method for manufacturing an antenna comprising an insulating substrate and a conductor line formed on the insulating substrate, wherein the surface of the insulating substrate including a layer containing a polyimide resin having a siloxane structure on at least the surface is treated with an alkali. And a process for forming the conductor line by an electroless plating process. The polyimide resin having the siloxane structure is a polyimide resin composed of an acid dianhydride component and a diamine component containing a diamine represented by the following general formula (1). Antenna manufacturing method.

(In the formula, g represents an integer of 1 or more. R ¹¹ and R ²² may be the same or different and each represents an alkylene group or a phenylene group. R ³³ , R ⁴⁴ , R ⁵⁵ , R ⁶⁶ Each may be the same or different and each represents an alkyl group, a phenyl group or a phenoxy group.) A through-hole formed in the insulating substrate through at least one terminal of the conductor line formed on the insulating substrate and an electric circuit formed on the surface of the insulating substrate different from the surface on which the conductor line is formed The method for manufacturing an antenna according to claim 5, further comprising a process of electrically connecting through the hole. The method for manufacturing an antenna according to claim 7, wherein the electrically connecting process is a process including at least an electroless plating process.

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