John Yundt | SunRay Scientific: Why are packaging engineers replacing wire bonding and copper hybrid bonding with direct-to-pad anisotropic epoxies?
00:12:34.515 - 00:13:48.065
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Why are packaging engineers replacing wire bonding and copper hybrid bonding with direct-to-pad anisotropic epoxies?
Advanced packaging architectures can bypass traditional copper hybrid bonding and complex wire-bonding setups altogether. By placing the anisotropic conductive epoxy directly in the footprint of a flip-chip or reverse die, designers can establish direct pad-to-component connections without the need for solder bumps or secondary underfilling.
In multi-layer and system-in-package (SiP) designs, this low-temperature process replaces complex blind via fills and standard wire-bond pyramids. Reversing the chip-stacking pyramid allows the magnetic Z-axis epoxy to complete vertical interconnects across multiple layers simultaneously, self-encapsulating the system to drastically reduce parasitic capacitance.
Furthermore, unlike high-vacuum copper hybrid bonding which demands perfectly planarized, polished surfaces, this fluidic polymer approach accommodates surface non-uniformities. It forms robust connections directly between unpolished die faces, significantly lowering processing complexity, thermal budgets, and manufacturing costs.
In this short video, you can learn:
* How direct-to-pad anisotropic epoxy eliminates the need for solder bumps and secondary underfill.
* Techniques for replacing wire bonds and reducing package parasitics through reverse chip stacking and simultaneous multi-layer interconnects.
* Bypassing the strict planarization and polishing constraints of copper hybrid bonding using conformable Z-axis polymers.
📋 **Clip Abstract** Explore how anisotropic conductive epoxy simplifies semiconductor packaging by replacing solder bumps, wire bonds, and copper hybrid bonding. Learn how this low-temperature, self-underfilling process manages multi-layer chip stacks while tolerating surface roughness.
#AnisotropicConductiveEpoxy, #DirectToPad, #ReverseChipStacking, #ZAxisInterconnects, #AdvancedPackaging, #SystemInPackage
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00:01:40 - 00:03:08
Why force pressure on delicate flexible substrates when magnetic fields can self-assemble your electrical interconnections?
Can magnetic field alignment overcome the thermomechanical stress limitations of traditional anisotropic conductive films?
The integration of fine-pitch components on flexible and heat-sensitive substrates requires a departure from conventional thermal-compression bonding. Standard anisotropic conductive films (ACFs), adhesives (ACAs), and pastes (ACPs) rely on thermode-based heat and pressure to force conductive particles into contact. This mechanical approach introduces localized stress and thermal budgets that can degrade delicate printed electronics and polymer substrates.
An elegant alternative lies in a magnetically aligned, anisotropic conductive epoxy that bypasses these mechanical constraints entirely. Rather than patterning the material or applying high pressure, the system utilizes a magnetic carrier pallet during the curing phase. This pallet establishes a precise magnetic field that organizes ferromagnetic particles into vertical columns, achieving reliable z-axis interconnection without requiring high heat or physical force.
This magnetic column alignment yields exceptional electrical isolation between adjacent contacts while maintaining highly conductive vertical pathways. The resulting two-part polymer epoxy system achieves an incredibly low resistance of seven to twenty milliohm centimeters. This performance surpasses typical electrically conductive adhesives (ECAs), ACFs, and ACAs, bridging the gap between standard conductive adhesives and pure metallic solder.
In this short video, you can learn:
* How magnetic field alignment replaces thermode pressure and high heat for anisotropic functionalization.
* The role of a magnetic carrier pallet in establishing vertical ferromagnetic particle columns during SMT curing.
* How the electrical resistance of this two-part polymer epoxy compares to traditional ECAs, ACFs, and metallic solder.
📋 **Clip Abstract** The speaker introduces ZeTac, a non-film-based anisotropic conductive epoxy that functionalizes via magnetic alignment rather than heat and pressure. He explains how a magnetic carrier pallet aligns ferromagnetic particles into columns during curing, delivering low electrical resistance and high isolation compared to traditional ACFs and ECAs.
🎤 Speaker: John Yundt
🏢 Company: SunRay Scientific
📅 Event: Additive, Sustainable or 3D Electronics Innovations Day 2025
📍 Location: TechBlick Online Platform
🌐 Learn more at the next TechBlick event: https://www.techblick.com
#MagneticAlignment, #AnisotropicConductiveEpoxy, #PressurelessBonding, #ZAxisInterconnects, #FlexibleHybridElectronics, #StretchableElectronics
00:07:21 - 00:09:09
Can you achieve a 100% solid, z-axis conductive joint in under 30 seconds using a top-down UV cure with zero heat?
Can you achieve a 100% solid, z-axis conductive joint in under 30 seconds using a top-down UV cure with zero heat?
The introduction of true UV-curable z-axis conductive adhesives represents a major leap forward for high-throughput, heat-sensitive electronic packaging. Unlike hybrid systems that require a secondary thermal post-cure to achieve full cross-linking, this advanced formulation polymerizes in seconds under broad-spectrum UV light. This rapid reaction time makes it highly compatible with ultra-fast, roll-to-roll manufacturing lines for applications like RFID chip attachment and smart labeling.
One of the fundamental challenges of using top-down UV curing in microelectronics is "shadowing"—where the opaque silicon die or component body blocks the UV light from reaching the adhesive underneath. To address this, specialized shadow-curing chemistry is built into the adhesive formulation. This IP-protected mechanism allows the polymerization reaction to propagate horizontally beneath the component from the exposed outer edges, ensuring a complete and uniform cure under the entire die.
The resulting joint behaves like an underfill, providing high mechanical shear strength alongside excellent anisotropic electrical performance. By eliminating heat completely from the cure process, this technology opens the door to high-yield assemblies on extremely sensitive, low-cost plastic substrates.
In this short video, you can learn:
* The chemical mechanics of a true UV-curable z-axis conductive adhesive that eliminates the need for secondary thermal baking.
* The innovative shadow-curing technology that enables polymerization to propagate horizontally beneath opaque silicon components.
* High-throughput roll-to-roll compatibility for ultra-fast packaging of RFID tags, smart labels, and flexible hybrid electronics.
📋 **Clip Abstract** This clip introduces a novel UV-curable anisotropic conductive adhesive capable of fast polymerization without secondary thermal steps. It highlights the shadow-curing chemistry used to propagate polymerization underneath opaque components, enabling robust joints on heat-sensitive substrates.
#AnisotropicConductiveAdhesive, #ShadowCuringChemistry, #UVCurableAdhesives, #ZAxisConductiveAdhesive, #FlexibleHybridElectronics, #RollToRollManufacturing
00:05:23 - 00:07:21
Is the massive capital expenditure of upgrading SMT lines holding your advanced materials back from high-volume production?
Is the massive capital expenditure of upgrading SMT lines holding your advanced materials back from high-volume production?
Deploying novel electronic materials often stalls at the commercialization phase due to the high capital expenditure required to modify production lines. To overcome this, the Z TAC process is designed to seamlessly integrate with standard Surface Mount Technology (SMT) lines. By avoiding complex equipment overhauls, manufacturers can scale up advanced assemblies using existing stencil printing and high-speed pick-and-place systems.
The only hardware addition required is a proprietary magnetic carrier pallet, known as the "zag pallet." Constructed with an aluminum frame and an embedded array of custom rare-earth magnets, the pallet creates the exact magnetic field profile needed to align the ferromagnetic particles during the cure phase. This carrier moves along the line just like a traditional reflow pallet, carrying the printed flexible circuitry directly into standard reflow or batch ovens.
By coupling custom magnetic tooling with specialized material formulation, this system ensures high-density, fine-pitch component placement down to 100 microns (and targeting 20 microns) with yields exceeding 98 percent. It illustrates a highly practical pathway for scaling next-generation materials from prototype to high-volume manufacturing without a massive CapEx hurdle.
In this short video, you can learn:
* The step-by-step workflow of integrating a magnetically-aligned epoxy into standard, high-volume SMT production lines.
* How custom-designed rare-earth magnetic pallets induce localized vertical column alignment during the standard thermal curing or reflow stage.
* Commercial scaling strategies that bypass massive capital equipment costs when transitioning advanced materials from lab to fab.
📋 **Clip Abstract** This clip explains how the Z TAC system integrates into existing SMT assembly lines with minimal equipment modifications. By using specialized magnetic carrier pallets during standard reflow processes, manufacturers can scale fine-pitch flexible electronics production with low CapEx.
#ZTACProcess, #MagneticallyAlignedEpoxy, #ZagPallet, #FinePitchAssembly, #FlexibleElectronics, #PrintedElectronics