Download the 3800 Data Sheet Wafer-Level Packaging Die Attach Au and Pt Wire Bonder Automating MEMS Assembly


Chip-on-Board, or COB, applications consist of die directly attached to its circuit board. COB assemblies improve package performance as a result of the shorter interconnection paths and are a preferred application by process engineers.

COB technology is actually 'direct chip attachment', or DCA. Direct Chip Attachment assemblies can be called different names depending on substrate material. For example chip-on-glass (COG), chip-on-flex (COF), among others. 

The COB process often has 3 steps:COB chip on board

  1. Die attach
  2. Wire bonding
  3. Encapsulation of the die and wires

The flip chip process incorporated with COB enables successful attachment without using wire bonding; it does so by bumping the bond pads on the correct side (via flipping the chip) and directly attaching the chip. With Flip Chip on Board (FCOB), underfilling the chip is required to protect the chip's active surface from damage.

Palomar Technologies Solution

Palomar Technologies offers two automated equipment solutions for die attach:

  1. 6500 Die Bonder - 1.5 micron, ultra high-accuracy die bonder 
  2. 3880 Die Bonder - high-accuracy, ultra-flexible die bonder

Both the 6500 Die Bonder and 3880 Die Bonder are designed for high-accuracy die attach, flexibility and factory automation. Chip-on-Board applications can be performed doing just direct chip attachment, or incorporation of a flipper for flip chip. These die bonder machines can also be retrofitted with conveyors and handlers, automatically feeding the package into a wire bonder.

Depending on application requirements, the three-step COB package can be successfully accomplished in a single run.

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