SE517314C2 - Method for providing a conductive element and a conductive element thereof - Google Patents

Abstract

The present invention relates to a method of providing a conductor (440, 510, 510') applied on a carrying substrate (430, 520, 520'), said conductor being provided such that an electromagnetic wave flows a distance from a first point to a second point and at least one surface (330, 340) of said conductor between said first and second point at least partly exhibits irregularities (460). The method comprises the step of exposing said conductor at least between said first point and said second point to an after-treatment such that said irregularities are reduced and said distance is abbreviated.

Description

10 15 20 fx) UI 30 517 314 nu nu in particular the microwaves, in a negative way then the microwave, which floats on the surfaces of leader, must take a much longer path.

A new microstrip device for use on a circuit board or in an antenna device is disclosed in International Patent Application No. PCT / SE98 / O2092 by the same applicant the. According to this application, the first and second microstrip conductors, with substantially the same dimensions in their longitudinal and transverse directions, are arranged in parallel in each side of a dielectric material and connects galvanically by means of a connection part. Figures 1 and 2 show an embodiment according to this application. The microstrip device 100 includes a first conductor layer 110 and a second conductor layer 120 disposed on each side of a dielectric substrate 130a and interconnected by connection 140. It the second conductor layer 120 is buried inside a layer 130b of a circuit board, e.g. by heat press gluing of a laminate (130b) over the conductor. The covering layer can also be arranged to cover the first conductive layer 110 and the substrate 130a. They also affect here the above mentioned properties of the microstrip conductors, in particular of the other layer 120, depending on the properties of the microwaves.

SUMMARY OF THE INVENTION The main object of the present invention is to provide a method to produce the conductors arranged on or inside a substrate, in particular microstrip conductors, so that the above-mentioned oj substances are reduced or decreased.

Another object of the present invention is to provide a method of enhance the performance of the microstrip antennas by increasing the microwave path axes.

For these reasons, a method of providing a conductor is provided on a supporting substrate. The conductor is provided so that an electromagnetic wave flows one extend from a first point to a second point and at least one surface of said conductor between said first and second point at least partially show irregularities. According to this method exposes said conductor at least between said first point and said second point for a subsequent treatment so that said irregularities are reduced and 10 20 25 30 517 314 said distance is shortened.

The subsequent treatment preferably consists of plating or a chemical or electrolytic planing, and the subsequent treatment is carried out after a conventional etching process. Consequently, the subsequent process is a removal, reduction or surface leveling process.

The supporting substrate is advantageously a circuit board. In one embodiment, the conductor is thin film of copper or planed copper arranged by etching, adhesion or the like.

As a result of the treatment, said irregularities are formed to substantially soft swells after said subsequent treatment. The treatment affects the limbs in at least stone the longitudinal and / or transverse direction of the conductor.

The electrolyte material is preferably copper.

The conductor after said subsequent treatment has a substantially semicircular cross-section. section, or the conductor after said subsequent treatment has a substantially rectangular shape and substantially beveled corners.

The plating thickness is preferably about 2 to 5 μm and the plating has very low current density to achieve a dense surface with small metal crystals. Also includes said subsequent treatment a polishing agent.

The invention also relates to a conductor and a circuit board set. The conductor is arranged on a support substrate and is provided so that an electromagnetic wave flows a distance from a first point to a second point, and at least one surface of said conductor between said first and second points exhibit at least in part oj subjects. Furthermore, the treated at least between said first point and said second point said oj subjects and said distance is shortened. The treatment consists of plating, or the treatment includes a chemical or electrolytic ling. The conductor can also be provided by the etching process and said treatment. 10 15 20 25 30 517 314 4 arranged after the etching process. The set is advantageously part of a micro- strip antenna.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described in more detail in a non-limiting manner and with reference to the accompanying drawings, in which; Fig. 1 shows a schematic illustration of an embodiment according to the prior art. point, Fig. 2 shows an enlarged part of Fig. 1, Fig. 3 shows a view of an enlarged area of a circuit board with a conductor arranged thereon, Fig. 4 is a schematic and enlarged illustration of a conductive layer arranged on one carriers processed according to the present invention, and Figs. 5a and 5b show schematic cross-sections through two embodiments, provided by the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS According to a preferred embodiment, a conductor, in particular a conductor for electrical magnetic waves, and in particular a microwave conductor, on a supporting substrate, are exposed following a conventional etching process for a subsequent treatment in the form of removal reduction / surface leveling process. The reduction process involves beneficial plating by chemical and / or electrolytic planing.

The plating, in accordance with the invention, is then performed as a desired guide. layers have been provided on the substrate, i.e. the circuit board. The leader can be a thin film of copper or planed copper produced by etching or the like. Although both 10 15 25 30 517 314 O. o o o o o | u ø o ao 5 chemical and electrolytic plating are possible the electrolytic plating is preferred because, as is well known, it will form the leader in a way that is more beneficial for transmission. It is particularly applicable when arranged with a distributor. networks, e.g. at a microstrip patch antenna, where all conductors are connected. According to invention, it is also possible to combine etching and plating: in a first step a conductor is constructed which comprises layers of thin film, preferably by plating when it is desirable to connect all the members during the electrolytic process: in it second step, parts of the members are removed by etching. The plating / electrolyte bath shall contain agents with high polishing properties.

An example of an electrolytic bath is a common electrocarbon bath to produce place removable electroplating of copper on a circuit board. The bath strives to smooth all ridges and uneven surfaces into bevelled shapes. The irregularities are then formed to substantially soft swells or similar smooth shapes. Fig. 4 shows a section along the longitudinal direction of a conductor 410. The dymings are denoted by 440. The circuit the card is denoted by 430. The preceding oj subjects are denoted by 460. It electrolytic material, preferably copper has flowed inside the field of irregularities and so that a substantially smooth surface is achieved. Although this figure shows a longitudinal transverse section, the transverse cross-section of the conductor can also have substantially the same effect as shown in Fig. 5a, in which a conductor 510 is mounted on a substrate 520 having a substantially rectangular cross-section is reduced to a substantially semicircular shape in cross-section cut.

In an overview of different applications, it is also possible to process the leader into different ones forms. Pig. 5b has a conductor 510 'arranged on a substrate 520', in which only the hay is beveled into semicircles. It is also possible, e.g. depending on the current density to form sharp corners by depositing more metal (copper), which then more to swell out and build convex protrusions. The chamfered corners can affect the in a positive way for lower transmission current densities. The embodiment according to Fig. 5a, however, is more suitable for high frequencies (eg> 40 GHz).

The plating thickness produced will be about 2 to 5 (Dm, which has nu nu nu nu v 0 o 0 u u u o o o man n n n n. u u n n n 0 n 1 1 a o u on nano ou nu 517 314 a very low current density to achieve a dense surface with small metal crystals.

The invention is not limited to the embodiments shown but can be varied on one number of ways without departing from the scope of the appended claims, and the device and the method can be implemented in different ways depending on the application, functional units, needs and requirements etc. ..-one O n O :sauna

Claims (20)

517 314 i * PATENT REQUIREMENTS A method of providing a conductor (440, 510, 510 ') disposed on a support substrate (430, 520, 520'), said conductor being provided such that an electromagnetic wave fl travels a distance from a first point to a second point, and at least one surface (330, 340) of said conductor between said first and second points at least partially has irregularities (460), characterized in that said conductor is subjected to a subsequent treatment at least between said first and second point such that said irregularities are reduced and said distance is shortened. The method according to claim 1, characterized in that said subsequent treatment consists of plating. The method according to claim 1, characterized in that subsequent treatment includes a chemical or electrolytic planing. The method according to any one of the preceding claims, characterized in that said subsequent treatment is carried out after a conventional etching process. The method according to any one of the preceding claims, characterized in that subsequent treatment is a removal, reduction or surface leveling process. The method according to any one of the preceding claims, characterized in that said support substrate is a circuit board. 517 314 3 The method according to any one of the preceding claims, characterized in that said conductor is a thin film of copper or planed copper arranged by etching, adhesion or the like. The method according to any one of the preceding claims, characterized in that said irregularities are formed into substantially soft swells after said subsequent treatment. The method according to any one of the preceding claims, characterized in that said treatment affects the conductor in at least longitudinal and / or transverse direction of the conductor. The method according to claim 3, characterized in that an electrolytic material is preferably copper. ll. The method according to claim 9, characterized in that said conductor after said subsequent treatment has a substantially semicircular cross-section. The method according to claim 9, characterized in that said conductor after said subsequent treatment has a substantially rectangular shape with substantially bevelled corners. The method according to claim 2, characterized in that said plating thickness is about 2 to 5 tm. 517 314 07 The method according to claim 13, characterized in that the plating has a very low current density to achieve a dense surface with small metal crystals. The method according to claim 1, characterized in that subsequent treatment includes a surface polishing agent. A conductor (440, 510, 510 ') and circuit board set (430, 520, 520'), said conductor arranged on a supporting substrate and provided so that an electromagnetic wave flows a distance from a first point to a second point, and at least one surface (330, 340) of said conductor between the first and second points at least partially has irregularities (460), characterized in that said conductor is further treated so that said irregularities are reduced at least between said first point and said second points and said second points distance is shortened. The set according to claim 16, characterized in that said treatment consists of plating. The set of claim 16, characterized in that said treatment includes a chemical or electrolytic planer. The set according to any one of claims 16-18, characterized in that said conductor is provided by means of an etching process and said treatment is arranged after the etching process. 517 314/0 los ø ø a a o n o n | now The set-up according to any one of claims 16-19, characterized in that the set-up is part of a microstrip antenna.