LIGA Technology & Monolithic Compliant Interconnect

Ever higher packing densities and steadily increasing signal speeds for semiconductor components make it increasingly difficult to contact devices under test (DUT) with the required signal integrity. Traditional spring contact pins - produced using classic manufacturing methods - cannot be minimized to the required extent.

Therefore Rosenberger uses the so-called LIGA process (lithography, electroplating, molding): using methods from semiconductor production, very small and equally complex mechanisms are produced. The MCI contact pin manufactured using the LIGA process offers structural elements in a size range of 10 μm; the mechanical and electrical properties are optimized due to the special geometry of the contact pin. With the LIGA process, Rosenberger is currently producing, for example, a range of test probes explicitly for microwave wafers and PCB test systems.

This patented technology ensures high-precision measurements with low contact resistance and excellent impedance control. There is only transmission of the high-frequency microwave signal to the coplanar contact structure within the shielded, air-insulated probe body. This maintains signal integrity at constant power in a temperature range from 10 K to 300 °C.

Contacting the test object with Rosenberger test probes is uncomplicated, reproducible and requires significantly reduced overtravel than before. This is due to the robust design of the coplanar contact structure and the omission of the micro-coax cable in the test tip.

Features of the Rosenberger test probes:

• Frequency range: direct current up to 67 GHz
• High performance 16 W at 5 GHz
• Standard grid dimensions: 50 µm to 2,500 mm
• Contact cycles: > 1,000,000
   

MCI contact elements are manufactured in an electroforming process. They meet the highest precision requirements with a small form factor due to the metal being built up in an additive process. With this procedure Rosenberger is able to reproduce parts on a microscale with a depth of detail down to 3 µm.

The additive process enables the development of extremely small and precisely defined shapes that can be produced with repeat accuracy. The precisely defined geometry forms the basis of a compact and reliable design: tailor-made for the individual application using Rosenberger Group’s many years of experience and competence in the development and manufacture of micro components. Innovative tools for design, simulation and verification are used throughout the company's own production facilities.

Classic application examples of these manufactured parts are interposer or board-to-board connections.

What distinguishes Rosenberger products?

• High reliability and durability
• Excellent signal integrity
• High packing density
• Precise contact force
• Low and stable contact resistance