RFID Assembly

RFID (Radio Frequency Identification) tags are used as an alternative to bar codes for inventory control and theft protection.  Sizes are typically a few millimeters square down to several hundred microns.

The most common use of a FINEPLACER® in the RFID domain is as a process development tool.  Due to its modular application flexibility, the tool provides several processes for evaluation prior to full scale production, such as adhesive bonding, thermo-sonic bonding, dispense and UV cure.  Optimized process parameters can be readily evaluated, such as temperature, time, force and ultra-sonic energy. 

R&D test assemblies can be set up quickly for rapid prototyping to find the correct material combination and to generate samples for:

  • Adhesive testing
  • Ageing tests
  • Electrical optimization
  • Fatigue tests

All steps of RFID assembly can be accomplished with a FINEPLACER® in either a manual or automatic system.

  • RFID chip size
    RFID chip at fingertip

What are the Challenges?

  • Need for a flexible and easy to use system for process development
  • Quick adaptation to different bonding technologies required
  • High variety of designs creates many variables in the parameters
  • Demand for specialized bonding equipment with very accurate thermal management
  • As RFID technology matures, component viewing and handling become more critical

The Finetech Solution

Substrate Materials and Chip Characteristics

  • RFID Polyethylenterephthalate substrate
    PET substrate

The typical substrate material is Polyethylenterephthalate (PET), which is thin (down to 0.1 mm), soft, flexible and thermally sensitive (max. 80°C). These properties necessitate well controlled process parameters during the bonding process. Furthermore, an appropriate vacuum holder is necessary to ensure an even working area.

Because of the substrate’s “floppiness”, underfill or encapsulation is essential.
Components are passive RF circuits having two or three bumps. Being typical two-pole circuits, they need an additional third bump only for mechanical stability.

Process Development in Preparation of Full Scale Production

The most common use of a FINEPLACER® in the RFID domain is as a process development tool.  Due to its modular application flexibility, the tool offers several processes for evaluation prior to full scale production, such as adhesive bonding, thermo-sonic bonding, dispense and UV cure.  Optimized process parameters can be readily evaluated, such as temperature, time, force and ultra-sonic energy. 

R&D test assemblies can be set up quickly for rapid prototyping to find the correct material combination and to generate samples for:

  • Adhesive testing
  • Ageing tests
  • Electrical optimization
  • Fatigue tests

Bonding Method 1: Ultrasonic Bonding

  • RFID placement component
    Overlay image of component’s underside and structure on substrate
  • RFID chip after placement
    RFID chip after placement

During alignment and placement, the chip is held on the die collet by vacuum. During the bonding process, the die collet executes transverse oscillations, transferring energy to the die/substrate-interface by friction. Typical frequencies are ~60 kHz.

Typical  bonding parameters for an RFID chip are:

  • Power = 1 W
  • T = from room temperature up to 80°C
  • Time (of ultrasonic vibration) = 500 ms

Bonding Method 2: Adhesive Technology – ACP

  • RFID placement image overlay
    Overlay image of component’s underside and structure on substrate, including ACP dot
  • RFID placement chip and antenna
    Process camera view of chip and antenna
  • RFID after placement and bonding
    RFID chip after placement and bonding with ACP

Anisotropic paste (ACP) is dispensed onto the antenna and a chip picked from a wafer,  then aligned and placed. During handling, the chip is held by vacuum. Using the process camera, placement and subsequent curing can be viewed on the monitor.

FINEPLACER® Bonding Systems

  • FINEPLACER® femto 2
    Automated Prototype2Production Bonder
  • FINEPLACER® sigma
    Semi-automated sub-micron bonder
  • FINEPLACER® lambda
    Flexible sub-micron die bonder
  • FINEPLACER® pico ma
    Multi-purpose die bonder

Due to the modular design approach, FINEPLACER® bonding systems can be configured for virtually any application challenge.

The main distinguishing features between the machines are the

  • degree of automation
  • optical resolution and
  • placement accuracy

Browse our product range or get in contact with your sales contact to figure out the best equipment solution for your specific application requirements.

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