Competing Fracture Modeling of Thin Chip Pick-Up Process

Huang

IEEE Trans. Compon., Packag. Manufact. Technol.

et al. 2014

Self Cite

Flip chip packaging as a mainstream packaging interconnect technology has proliferated rapidly within the last decade or so. With the applications of high-performance chip, its thickness and size have been much thinner and bigger, which is challenging the current assembly technique, especially for the reliable peeling of ultrathin die from the wafer due to its vulnerability and flexibility. Here, we present some significant analytical formulas to estimate die cracking stress and peeling energy in die peeling process. The effects of two factors, including peeling cracking propagation and ejecting needle configuration, are investigated using a fracture mechanics framework. Meanwhile, all analytical predictions have been verified via finite element modeling with virtual crack technique. Theoretical results have shown that die cracking stress could be effectively reduced, but it rarely works to improve peeling energy when more needles are embedded below the adhesive tape. In particular, the essence of the technique with the multineedle is discussed, compared with the normal single-needle technique, which can be used to guide the design of ultrathin die peeling process.Index Terms-Adhesive layer, chip peeling-off, die-cracking stress, energy release rate (ERR), microelectronic packaging, multineedle ejector.

Section: B Effects Of Crack Length and Distance Between Adjacent Neementioning

confidence: 71%

mentioning

confidence: 99%

See 1 more Smart Citation

Reliable Peeling of Ultrathin Die With Multineedle Ejector

Huang

IEEE Trans. Compon., Packag. Manufact. Technol.

et al. 2014

Self Cite

Sci. China Technol. Sci.

“…These undesired phenomena are induced by the force of the ejector pin, the relative movement of the pickup head, and the requirement for high-speed placement. Owing to the rapid growth of the flexible electronics market, Yin's research group at HUST proposed a competitive index quantitative evaluation method for chip peel ability [40][41][42]. The competitive behaviors of chip stripping and fracture and their influencing mechanisms were revealed.…”

Section: Flip Chip Technologymentioning

confidence: 99%

Flexible electronics manufacturing technology and equipment

Yin

Huang

Yang

et al. 2022

Self Cite

Flexible electronics such as mechanically compliant displays, sensors and solar cells, have important applications in the fields of energy, national defence and biomedicine, etc. Various types of flexible electronics have been proposed or developed by the improvements in structural designs, material properties and device integrations. However, the manufacturing of flexible electronics receives little attention, which limits its mass production and industrialization. The increasing demands on the size, functionality, resolution ratio and reliability of flexible electronics bring several significant challenges in their manufacturing processes. This work aims to report the state-of-art technologies and applications of flexible electronics manufacturing. Three key technologies including electrohydrodynamic direct-writing, flip chip and automatic optical inspection are highlighted. The mechanism and developments of these technologies are discussed in detail. Based on these technologies, the present work develops three kinds of manufacturing equipment, i.e., inkjet printing manufacturing equipment, robotized additive manufacturing equipment, and roll-to-roll manufacturing equipment. The advanced manufacturing processes, equipment and systems for flexible electronics pave the way for applications of new displays, smart sensing skins and epidermal electronics, etc. By reviewing the developments of flexible electronics manufacturing technology and equipment, it can be found that the existing advances greatly promote the applications and commercialization of flexible electronics. Since flexible electronics manufacturing contains many multi-disciplinary problems, the current investigations are confronted with great challenges. Therefore, further developments of the reviewed manufacturing technology and equipment are necessary to break the current limitations of manufacturing resolution, efficiency and reliability. flexible electronics, micro/nano manufacturing, electrohydrodynamic direct-writing, flip chip, automatic optical inspection

“…[ 15–21 ] The key in assembly process is to regulate interfacial adhesion states between strong for pick‐up and weak for printing in a robust and repeatable manner. Conventional pick‐and‐place technique, [ 22–26 ] which utilizes a small vacuum chunk to pick up and release the chip, has shown excellent performance in controlling the interfacial adhesion. [ 22 ] However, the scaling of the vacuum system down for chips with a lateral dimension smaller than 80 µm and a thickness thinner than 50 µm still remains a great challenge.…”

Section: Introductionmentioning

confidence: 99%

Thermal Controlled Tunable Adhesive for Deterministic Assembly by Transfer Printing

Luo

Wang

et al. 2021

Adv Funct Materials

Transfer printing techniques based on tunable adhesives that enable heterogeneous integration of materials in desired layouts are essential for developing existing and envisioned systems such as flexible electronics and micro‐LED (µ‐LED) displays. Here, a novel thermal controlled tunable adhesive, which not only has the ability of eliminating the interfacial adhesion for printing but also provides a new strategy for enhancing the interfacial adhesion for pick‐up is reported. The tunable adhesive features cavities filled with air on the surface. This simple construct offers thermal controlled suction and thrust with their amplitudes on the order of a few tens of kPa within 100 °C temperature change, which enables a reliable damage‐free transfer printing. Systematically theoretical and experimental studies reveal the underlying thermal induced pressure change mechanism and provide insights into the design and operation of the thermal controlled tunable adhesive. Demonstrations of this smart adhesive in manipulation of various surfaces and transfer printing of micro‐scale Si inks and µ‐LEDs illustrate its unusual capabilities for deterministic assembly by transfer printing.