Chippackaging is a very important part of semiconductor manufacturing process.   As Moore's Law slows down, it is difficultfor chip processes to continue reducing feature sizes. Advanced packaging hasbecome a major technical highlight to improve chip performance and open up thedevelopment path of "More than Moore". The development of traditionalpackaging to advanced packaging has made great progress to the goal of higherintegration, better performance and smaller size.

In theentire chip packaging process, die bonder has always played a pivotal role. Itrealizes the precise alignment and firm combination between the chip and thepackage substrate, ensuring the stable adhesion and reliable connection of thechip. Especially with the rapid development of advanced packaging technology,die bonder should have more accurate positioning, more stable motion control,and more powerful adhesion system to meet the precision and reliable executionrequirements of advanced packaging technology.

Basedon the introduction of traditional packaging and advanced packaging technology,this paper will explain the important role of die bonder in advanced packaging,aiming at providing useful knowledge reference for readers to understand thedevelopment of advanced packaging technology and equipment.

Thetraditional packaging process step is to first cut and fragment the wafer, andthen Package the chip separately, and then assemble it on the PCB motherboardto form a complete system, or mount different chips to the same PackageSubstrate, and then complete the system-level packaging. This type of packagemainly relies on gold wire to connect the lead to the chip. In theory, thelonger the information transmission distance between chips, the slower theinformation transmission, the lower the performance of the chipset system, andtraditional packaging limits the potential for signal transmission speed andperformance improvement. At the same time, due to the low package density, linewidth and pin spacing are difficult to achieve less than 200 microns, whichlimits the development of high integration of chips.

Traditionalpackaging mainly includes DIP, SOP, SOT, TO, BGA and other packaging forms, thepackaging process is relatively simple and mature, the packaging form isrelatively single, mainly focusing on component-level packaging, system-levelpackaging is difficult to achieve. In addition, the package size is too large,which deviates from the development direction of modern thin and shortelectronic products. In general, traditional packaging is facing bottlenecks indensity, size and performance, and it is difficult to meet the developmentneeds of modern electronic products.

Advancedpackaging, also known as high-density advanced packaging, is expected toaccount for more than 50% of the total packaging market by 2026, according toYole. Advanced packaging generally refers to packaging technologies thatintegrate different systems into the same package to achieve more efficientsystem efficiency.   It adopts advanceddesign ideas and advanced integration technology, shorths the length of leadinterconnect, and reconstructs the system package of the chip, which cangreatly improve the signal transmission speed and effectively improve thesystem function density.

At present, advanced packaging mainly includes fliptype package(Flip Chip, Bumping), wafer-level packaging (WLCSP, FOWLP, PLP),2.5D packaging (lnterposer, RDL), 3D packaging (TSV) and so on. The Flip Chipachieves high density interconnection by flipping the chip directly onto thecarrier.   Wafer-level packaging Testingbegins in wafer form. 2.5D packages are repackaged and Redistribution withsilicon substrates for high density stacking. 3D packaging utilizes TSVtechnology to vertically stack and interconnect different chips or components.

Advanced packaging has been widely used incomputer, communications, consumer electronics, medical, aerospace and otherfields, and promote the packaging technology and the entire electronicsindustry to move forward. At present, flip type package, 2.5D package, 3Dpackage is mainly used in memory, central processing unit (CPU), imageprocessing unit (GPU) and so on; Wafer level package is mainly used in poweramplifier, wireless connection device, RF transceiver and so on.

Advancedpackaging technology has achieved a major breakthrough in density, integration,performance and other aspects, and put forward a new challenge to packagingequipment. To achieve complex advanced packaging processes, it is necessary tohave more sophisticated and reliable packaging equipment as a guarantee. Amongthem, die bonder as a key equipment to achieve a solid connection between thechip and the carrier board, continuous innovation is needed to adapt to the newprocess of advanced packaging.

Theimportant functions of die bonder are:

(1) Thepositioning accuracy requirements of advanced packaging reach the micron level,and the solid crystal machine realizes precise chip placement and positioningto ensure the high-density interconnection of the package.

(2)Through hot pressing, laser and other ways to achieve a solid bond between thechip and the carrier plate without defects to ensure quality.

(3)Automatic feeding and transmission system, which can achieve efficient andstable mass packaging production.

(4)Online monitoring system to achieve closed-loop control of key processparameters such as temperature, pressure, etc., to ensure process stability.

Many manufacturers at home and abroad havelaunched equipment products specifically for advanced packaging. SuzhouBozhong Semiconductor company created the FastStar series of die bonder isa multi-functional and versatile die bonder for advanced packaging, which notonly meets the stable and high-precision patch, but also provides customerswith the ultimate production efficiency. Among them, the DU9721 product adoptsan open architecture and modular design, providing customers with the ultimateefficiency of on-demand customization, through the integration of glue,automatic tool change, hot pressing and other functions, can handle multi-sizewafers, can achieve a variety of substrate transfer methods, to meet the solidcrystal, MCM, Flip chip, SiP and other packaging processes.