DE7026104U - SHIELDED PROBE - Google Patents

Description

SIEMENS AKTIENGESELLSCHAFT München 2, the Berlin and Hünchen Witteisbacherplatz

107

Shielded measuring probe

The invention relates to a shielded measuring probe, in particular for measuring integrated components in layer and semiconductor (semiconductor) circuits.

With integrated thin or thick-film circuits, resistors, capacitors and coils can be made of layered components can be applied directly to a substrate, while active components are generally inserted into the network afterwards will. The layered components are subject to certain Manufacturing tolerances, so that when required very much A subsequent adjustment of the components is necessary with great accuracy. The same applies to integrated semiconductor circuits, in which the functionality of the semiconductor chip must be measured before being installed in a housing.

To measure the components, alternating current »- procedure applied. The components of the circuit are very fine, adjustable. Contacted measuring probes. The between parasitic inductances and capacitances occurring in the probes can in some cases significantly falsify the measurement result, especially in microelectronics.

While the parasitic inductances only through as possible

short supply lines can be reduced, the parasitic capacitances can be reduced by using shielded measuring probes can be reduced significantly. The prerequisite is that the measuring circuit or measuring bridge used is suitable for use

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shielded measuring probes suitable iet *

The object of the invention is to provide such a shielded MeBBonäe to indicate the particular »or measurement integrated components is suitable

The solution to this problem is characterized by that

the measuring probe consists of a shaft provided with a measuring socket consists of electrically good conductive material and that an insulation layer on the shaft and over the insulation layer a metal layer serving as a shield is applied "

This results in the advantages that between the unmixed Stray capacities occurring with measuring probes are significantly reduced and that this makes the measurement result much more accurate. The srfisäusgsgesSSe Messende is also sue Suitable for direct attachment to shielded cables.

The tip of the measuring probe preferably consists of a piece of metal soldered to the shaft, β. Β · made of hardened steel. In order to it is achieved that the mechanically highly stressed measuring tip is made of a particularly suitable material with a long service life and low contact resistance can be produced without the measuring probe being affected by the use of special Mate-C rials are too expensive or their manufacture is too laborious.

Other beneficial materials for the tip are tine Platinum alloy, which has a very small »constant contact resistance or tungsten carbide, which has a longer service life than gold-platinum and is also constant Has contact resistance.

Preferably, the tip of the measuring probe is rounded. To one To avoid damage to the layered components when making contact and to achieve a constant contact resistance.

The insulation layer is preferably made of cast resin. Of

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The advantage of this material is that it is after the actual Shaping of the measuring probe can be applied by dipping, spraying or pouring.

The insulation layer advantageously has tension resistance greater than 200 V and is around 50-100 µm thick.

The outer shielding metal layer advantageously consists of a 5-15 .mu.m thick copper layer, which is initially electroless and is then applied galvanically directly to the insulation layer.

The measuring probe according to the invention is to be explained in more detail in the form of an exemplary embodiment with the aid of the drawing.

In a partially sectioned representation, the shaft made of electrically conductive material can be seen at its front End of a measuring tip 2 made of a material with little contact «* resistor is soldered on. The surfaces of the shaft 1 and the measuring tip 2 are ground together after the soldering process. After the surface has been grinded flat, an insulating layer 3 made of cast resin is applied and cured which is then an approx. 5-15 µm thick copper layer, which is used as

Shielding is used, is knocked down.

In order to contact the measuring probe with the component to be measured au allow, the probe tip 2 is ground free at 21. The geometry of this free cut has on the Size of the remaining residual parasitic capacities. a decisive influence. By choosing the The distance between the shielding sleeve 4 and the tip of the probe can be the angle of the cut can be changed int large limits .. The smallest »practical The distance that can be produced is in the order of magnitude of 100-200 am. Among other things, avoid damaging the components when making contact, the tip of the probe is slightly rounded.

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The supply line to the measuring probe consists of a flexible cable as possible Coaxial cable which, as the drawing shows, can be connected directly to the measuring probe.

The inner conductor 5 is here soldered directly into a hole in the shaft 1, while the outer conductor 8 via a Insulation 7, e.g. B. a shrink tube, is pulled and soldered directly to the shielding metal layer 4. The diameter of the connecting cable and measuring probe are preferred chosen so that the diameter of the cable dielectric coincides approximately with the diameter of the measuring probe.

The measuring probe can be attached to a bond measuring head or micromanipulator in any way.

The shape of the measuring probe according to the invention is in no way limited to Irorm shown in the drawing is limited. The Pcva rather, the measuring probe depends on the particular application.

1 figure

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Claims (9)

UBLJi sayings 1) Shielded measuring probe, especially for measuring integrated Components, characterized in that they consist of a shaft (1) provided with a measuring tip (2) electrically conductive material and that on the shaft (1) an insulation layer (3) and over the insulation layer (3) A metal layer (4) serving as a shield is applied. 2) measuring probe according to claim 1, characterized in that that the tip of the measuring probe consists of a piece of metal soldered to the shaft. 3) measuring probe according to claim 1 or 2, characterized net that the tip is made of hardened steel. 4) measuring probe according to claim 1 or 2, characterized net that the tip is made of a gold-platinum alloy. 5) measuring probe according to claim 1 or 2, characterized gekennzeieh r net, that the tip of tungsten carbide is composed. 6) measuring probe according to claims 1 to 5, characterized in that that the probe tip is rounded. 7) Measuring probe according to at least one of claims 1 to 6, characterized in that the insulating layer is made of casting Resin is made. 8) measuring probe according to claim 7, characterized in that that the insulation layer has a voltage resistance greater than 200 Y and is about 50-1C0 pm thick. VPA 9 / 7U / 0020 - 6 - 712 · 1042 * 7.74 IMl fl * 9) measuring probe according to at least one of claims 1 to 8, characterized in that the outer metal layer is a 5-15 ψη thick copper layer « VPA 9/7 H / 0020 7821104 $ 2. 7. H.