DD295048A5 - METHOD FOR THERMALLY ABRASIVE MACHINING OF MULTILAYER SOLID-BODY SYSTEMS - Google Patents

Abstract

The invention relates to a method for the thermally abrading processing of multi-layer Festkoerpersystemen, which can be advantageously used in the production and the functional adjustment of electronic and micromechanical layer elements. According to the invention, a process is used in the processing of a multilayer solid-state system, wherein the layers characterized by different material compositions result in characteristic spectral lines in a plasma produced by the machining process, depending on the processing state, from whose repeatedly ascertained existence or nonexistence exactly on the Processing state is closed. The invention allows for automated processing and leads to quality improvements. FIG. 1 {laser processing; Micromachining; Prozeszsteuerung; Multilayer Festkoerpersystem; thermally-removing machining; spectroscopy; spectroscopic process sensor}

Description

Field of application of the invention

The invention relates to a method which can be advantageously used in the production and functional adjustment of electronic and micromechanical layer components.

Characteristic of the known state of the art

DD-PS125299 describes a method and an arrangement for generating emission spectra by means of

Laser radiation sources, wherein vaporized material is energized by energy. This solution is by

disadvantageous that a separation between the evaporation of the material and the generation of spectra is made and the arrangement no defined processing of the workpiece, but only a detailed evaluation of

Spectra allowed.

DD-PS 132213, DD-PS 133860 and DD-PS 222405 are methods for the qualitative and quantitative analysis of

Solid state spectra, especially in micro-spectral analysis, known.

These solutions have disadvantages in that only a detailed analysis of spectra is made and

no defined material processing can take place.

Furthermore, DD-PS 218014, DD-PS 239365 and DE-OS 3818734 disclose processes for the heat-removing machining of solid-state layer systems, wherein either the determination of a functional parameter (eg ohmic resistance) of the

Workpiece for detecting the defined processing of the layer system is used and the state of the layer system is not further investigated or no conclusions about the processing result during processing of the layer system are possible.

The publications DD-PS 266522, DE-OS 3733147, DE-OS 3820848 and DD-PS 236017 describe methods and

Arrangements for controlling tool parameters by obtaining and processing information from the

Site of action. These solutions are unsuitable for the differentiated processing of solid-state layer systems, since measured variables, such as temperature fields, reflection, absorption or tool parameters, such as laser beam profile or radiation intensity of a plasma are used, which do not allow conclusions about processes within a layer system and their application accordingly for the Processing of solids has been described.

Object of the invention

The object of the invention is to provide a process for / thermal ablation processing of multi-layer solid state system which permits automated, defined processing and thus leads to substantial quality improvements of products and to labor time savings.

Explanation of the essence of the invention

The object underlying the present invention is to provide a method which ensures the defined thermally ablative machining of multilayer solid-state systems by targeted determination and evaluation of characteristic processing parameters, wherein in the active site or in the workpiece no additional, via the interaction introduced energy tools of the tool with the workpiece and a touching probing of the workpiece can be avoided.

The problem is solved according to the invention in that a method for the thermally abrading processing of multilayer solid-state systems is used, wherein the layers are characterized by different material compositions and associated with the layers, starting with the layer facing a tool, atomic numbers, and the method steps:

a) removal of volume elements by the action of the tool on the multilayer solid-state system to form a plasma,

b) determining the existence or the nonexistence of a spectral line characterizing the material of a layer η in the emission spectrum of the plasma,

c) Determining the existence or nonexistence of a spectral line characterizing the material of a layer η + 1 in the emission spectrum of the plasma

be carried out in succession and repeated until the non-existence of the spectral line characterizing the material of the layer η and the existence of the spectral line characterizing the material of the layer η + 1 can be determined in the emission spectrum of the plasma.

The location of characteristic spectral lines in the emission spectrum is given by the consistency of the coating materials.

By the disappearance of the spectral line characterizing the layer η and by the existence of the spectral line characterizing the layer η + 1, the completed view of the view η is reliably concluded.

The inventive method thus takes place the removal of multi-layer solid state systems in conjunction with an on-line process control in defined catfish.

In concretization of the method is provided that with limited spectral sensitivity of means for determining the existence or nonexistence of the layer η + 1 characterizing spectral line or not possible

Feasibility of the material of the layer η + 1 in the plasma state by the tool of step c) is not carried out and the process steps a) to b) carried out in succession and repeated until the emission spectrum of the plasma characterizing the material of the layer η in the emission spectrum of the plasma Spectral line detectable

It is envisaged that the method steps a) to c) or a) to b) are carried out under relative movement of the multi-layer solid state system to the tool.

It is further envisaged that preferably an electron beam or a laser beam is used as a tool.

Ausfuhrungsbalsplol

The invention will be explained below with reference to a drawing with reference to an embodiment. The drawing shows

Fig. 1: multilayer solid state system

Fig. 2: Apparatus for carrying out the method.

According to FIG. 1, metallic layers with a respective layer thickness of 10 μm are located on a glass substrate 5:

Copper 4 with Cul ions in plasma 1 and major detection lines of 324.8 and 327.4 nm;

Silver 3 with agglomerates in plasma 1 and major detection lines of 328.1 and 3338.3 nm;

Gold 2 with Aul ions in plasma 1 and major trace lines of 242.8 and 267.6 nm.

The focused beam of a Q-switched cw-Nd: YAG laser acts on the multilayer solid state system to form a plasma cloud.

Depending on the removal depth, different spectral lines characterizing the layers are found in the emission spectrum of the plasma with wavelengths λ _{1 (} λ ₂ , X ₃ .

If the multilayer solid state system to be processed to such a state that the layers 2 and 3 are removed and the layer 4 is not present, so are the spectral lines of copper and silver in the plasma above an intensity threshold undetectable and the spectral lines of the Gold detectable. This state signals the end of the ablation process.

Likewise, the end of the abrasive machining can be defined with the same processing target so that the spectral lines of copper and silver are not detectable in the plasma.

For processing planar structures on the multilayer solid state system, the same is moved by means of a positioning system relative to a stationary, focused laser beam.

For certain applications (high volumes), the laser beam is replaced by an electron beam. Fig. 2 shows a simple arrangement for carrying out the method. The laser beam of the Q-switched cw Nd: YAG laser 10 is focused by an adjustable focusing unit 9 and directed by a beam splitter 8 on the multi-layer solid state system β, which is located on a computer-controlled two-coordinate drive 7. The plasma 1 formed at the point of action of the laser beam / multilayer solid-state system 6 is fed via the beam splitter 8 to a reflection-type imaging unit 3. A plasma spectroscopic process sensor 12 evaluates the existence or nonexistence of certain given before computer 11 spectral lines and passes the computer 11 corresponding information for process control. Based on this, the computer 11 controls both the Q-switched cw-Nd; YAG laser 10 and the computer-assisted two-coordinate drive 7.

Claims (5)

A process for the thermal ablation treatment of multi-layer solid state systems, wherein the layers characterized by different material compositions and the
Layers, starting with the tool-facing layer, are assigned ordinal numbers, characterized in that the method steps are: a) removal of volume elements by the action of the tool on the multi-layer solid state system to form a plasma; b) determining the existence or nonexistence of a material of a layer η
characterizing spectral line in the emission spectrum of the plasma; c) determining the existence or nonexistence of a material of a layer η + 1
characterizing spectral line in the emission spectrum of the plasma be carried out in succession and repeated until the non-existence of the spectral line characterizing the material of the layer η and the existence of the spiral line characterizing the material of the layer η + 1 can be determined in the emission spectrum of the plasma. 2. The method according to claim 1, characterized in that the method step c) is not carried out and the process steps a) to b) carried out in succession and repeated so often until the emission spectrum of the plasma the non-existence of the material of the layer η
characterizing spectral line is detectable. 3. The method according to claim 1 or 2, characterized in that the method steps under
Relative movement of the multi-layer solid state system are performed to the tool. 4. The method according to one or all of claims 1 to 3, characterized in that the tool is designed as an electron beam. 5. The method according to one or all of claims 1 to 3, characterized in that the
Workpiece is designed as a laser beam. For this 1 page drawings