Development Of Microelectronic Industry Research Articles

Balancing dielectric properties and dimensional stability of poly(amide-imide) films via introducing a micro-crosslinked structure

With the rise of 5G communication technology and the development of microelectronics industry, establishing a balance between dielectric constant (Dk) and coefficient of thermal expansion (CTE) becomes significant for polyimide. Herein, a series of poly(amide-imide) (PAI) films were fabricated by using pyrophthalic dianhydride, 4,4′-diaminodiphenyl ether and 4,4′-diaminobenzanilide containing an amide structure as constitutional units; and then 1,3,5-tris(4-aminophenoxy)benzene (TAPOB) as the crosslinker was introduced to form the crosslinked structure within PAI films. The results indicated that well-designed crosslinked network could effectively balance the relationship between dimensional stability and the dielectric properties of PAI films. With the addition of just 0.1 mmol TAPOB, the Dk of corresponding PAI films decreased to 3.37 (at 105 Hz), compared with unmodified PAI films. Furthermore, the CTE of such PAI film revealed a 50.6 % reduction, revealing the superior dimensional stability. This work provides a novel strategy to design high-performance polyimide films for a practical application in flexible printed circuit board.

Benzocyclobutene/vinylphenyl-introduced polycarbosilanes with low dielectric constant, high temperature performance and photopatternability

With the development of microelectronic industry, low dielectric-constant insulating materials with high temperature performance and photopatternability have aroused interest. In this work, a kind of benzocyclobutene/vinylphenyl-introduced polycarbosilanes (PVBCS) were synthesized by H2PtCl6 catalyzed ring-opening copolymerization of 4-(1-methylsilacyclobutyl) benzocyclobutene (4-MSCBBCB) and 1-methyl-1-(4-vinylphenyl) silacyclobutane (1-MVPSCB). By directly introducing photo-active groups on the pendants of polycarbosilanes, the PVBCS was endowed with photopatternability without additionally using any photo-initiators or photo-crosslinkers. DSC and FTIR characterization demonstrated that the PVBCS was UV&thermally curable. The UV curing was conducted at ambient temperature and the thermally curing was performed above 200 °C. TGA curves of the cured PVBCS indicated that the 5% weight loss temperature is 473 °C, which is above the required temperature limit. The cured PVBCS also has low dielectric constant of 2.32–2.40 in the range of 1 k∼1 MHz. The high temperature performance and low-dielectric constant could be attributed to the polycarbosilane main-chain structure and the benzocyclobutene-based cross-linked structure.

Hybrid Micro Circuits

Hybrid microcircuits (HMCs) are playing important roles in various electronic fields such as military, space, medical, computer, automotive, instrumentation, industry and consumer electronics etc. The strength of hybrid microelectronics is the ability to choose and mix different technologies to best meet the requirements of the application. The early hybrid microcircuits generally combined discrete transistors, diodes, capacitors and resistors to produce analog or digital circuits. But with the latest developments in microelectronics industry, the hybrid microelectronics has grown combining ICs, LSI & VLSI functions, GaAs devices, single and multiple chips, optical and superconductor chips on single monolithic ceramic substrate. For performing complex electrical functions, three-dimensional (3-D) integration is now made possible to produce advanced multi-chip and multi-layer hybrids known as multi chip modules (MCMs). High frequency, high power, higher reliability, size, weight, thermal performance, low cost and design to product turn around time are the important factors, which preferably decide the use of hybrid microelectronics. The present note introduces hybrid microcircuits, technologies for hybrid manufacturing, advanced hybrid technologies, advantages and various applications areas for hybrid microcircuits.