DELO has developed a new adhesive that can be used to create ultra-fine structures within seconds.DELO DUALBOND EG4797 thus creates new possibilities in heterogeneous integration and optical packaging applications. Able to realize unlimited freeform structures and razor-thin optical barriers, the material also answers to the ongoing trend towards miniaturization.
Illustration of microstructures, so-called micro dams, on a printed circuit board. Image Credit: DELO
The halogen- and solvent-free acrylate allows for extremely fine microstructure designs so-called micro dams in semiconductor packaging and on printed circuit boards. With it, bondlines with widths of less than 100 µm in an aspect ratio of five or more can be dispensed. Previously, achieving line widths of even 200 µm was considered a challenge. This new micro dam solution was developed in close partnership with NSW Automation, a systems manufacturer which produces high-precision microdispensing technologies for the semiconductor industry.
A special feature of DELO DUALBOND EG4797 is its high thixotropic index of 6.6. This enables high dispensing speeds of 15 mm/s or more, all while creating a stable microstructure layer by layer on straight as well as curved surfaces. Fine bondlines are dispensed using conical needles with a diameter of 100 µm.
After dispensing, the micro dam is cured in one step. The process can be set up flexibly while remaining energy efficient. Curing can either be carried out in 10 seconds using only UV light, in five minutes using only heat at +120 °C, or via a dual-curing process using both UV light and heat.
DELO DUALBOND EG4797 proves to be a very good adhesive in testing typical for compliance to microelectronics and semiconductor industry standards such as JEDEC MSL.
This new product comes in response to increasing demand for high-performance electronic components and the ongoing trend towards miniaturization, with more and more powerful functioning parts needing to be accommodated on PCBs.
Microstructures, for example, can serve as flow stops and reduce keep-out zones (KoZ). These are areas within a PCB layout that limit the flow of underfill adhesives used to reinforce solder contacts, thus protecting surrounding components. In optical packaging, such as in LED module manufacturing, micro dams extremely fine in structure act as optical barriers.
Due to ultra-fine micro dams and their various process options, freeform structures can take on an almost limitless number of designs, and new, unprecedented package layouts can be achieved. All the while, the amount of space required can be reduced to a minimum.
DELO DUALBOND EG4797 and other advanced packaging adhesives will be on display at the IMAPS Symposium from September 30 to October 3, 2024, in Boston, Massachusetts, USA, and at IEMT, which will take place from October 16–18, 2024, in Penang, Malaysia.
Micro Dam Dispensing: Smallest line width, highest aspect ratio | Electronic manufacturing
Video of micro dam dispensing: Smallest line width, highest aspect ratio. Video Credit: DELO