Corrosion is the degradation of metals as a result of electrochemical activity. Package overview development of ic package is a dynamic technology. Gold ball or gold wedge gold wire bonded to a gold bond pad is the most reliable wire bonding process. Wire bonding process is one of the most critical processes in the integrated circuit ic package. Wire bonding is the method of making interconnections between an integrated circuit ic or other semiconductor device and its packaging during semiconductor device fabrication. One side of a gold wire connects to the bonding pad while the other side connects to the package. In addition, pads having bond over active circuitry boac which are much more sensitive to pad cracks, are likely present in the same ic. The bond diagram shows an example for a 16 pin qfn. Usually, a longer bonding time of more than 15 milliseconds with high and gradually ramping up bond.
Su, in comprehensive semiconductor science and technology, 2011. Electrical and layout perspectives by lei he, shauki elassaad, yiyu shi, yu hu and wei yao contents 1 introduction 225 2 ic package tutorial 227 2. Application of ultrasonic energy forms a wedge bond. Lau asm pacific technology 1622 kung yip street, kwai chung, hong kong 85226192757, john. To meet such diverse range of requirements, ic package range encompasses over 30 different types. Waferlevel chipscale package fanin wlp and fanout wlp.
Chip bonding at the first level 98 integrated circuitengineering corporation. Refer to freescale package case outline drawings to obtain detailed dimensions and tolerances. Ic knowledge is dedicated to offering the finest training and reference materials available to the semiconductor industry. The package or substrate can be stationary, and the tool does all back and forth motion. Mechanical and thermal design guidelines for lidless flip. The powerpad package is not designed to be used without the exposed pad being soldered to the pcb. Long wire bonds can be detrimental to the overall package performance. By implementing effective layout patterns on bond pads in packaged ic products, not only the bond wire reliability can be improved, but. A thicker gold layer will have a favorable effect on bondability.
Pad ubm total height ubm cu pillar solder caplf amkor confidential information 4 dec12, r. Polyimide carrier film with an adhesive in reel form, is punched to create the inner lead bond. Crosssectional analysis of the cu ball on al pad further confirms that corrosion occurs primarily beneath the cu balls and does not initiate from the al pad. Quikpak, originally founded in 1994 as spt, was purchased by delphon industries in 2000. It is very important to keep the bond pad free from. The quality of the bond pad surface used for gold wire bonding is very critical for the overall package performance.
A repassivation layer is added on the bond pad, followed by the underbumpmetallization ubm and the bump. An900 application note introduction to semiconductor technology by microcontroller division applications introduction an integrated circuit is a small but sophisticated device implementing several electronic functions. The semiconductor packaging industry is undergoing a stepchange transition from gold to copper wire. The process of corrosion requires 4 components for it to occur. The short wire bonds are indication to down bonds e. Drawing on the packaging and assembly technologies accumulated since the inception of the semiconductor industry, toshiba has developed a broad range of products, including a package for largecapacity memory, a. By implementing effective layout patterns on bond pads in packaged ic products, not only the bond. Wire bonding there are basically two forms of wire bonds, wedge bonds and ball bonds. R0 27march 20 package details soic8 case tape dimensions and orientation dimensions in mm tape width. This means the bonding process is limited by how fast the tool can move from pad to pad. The package provides a means for connecting the package to the external environment, such as printed circuit board, via. The key parameters of the bond pad include pad metallization, gold or aluminum metallized surface thickness, pad cleanliness.
Ic knowledge products integrated circuit packaging this report. Guidelines for designing with lidless flipchip packages 6 xapp1 v1. Small outline integrated circuit an2409 application note rev. Square bond pad deep trench bonding area spacing metal 1. To serve the diverse needs of our worldclass semiconductor manufacturers, amkor offers more than 3000 different package formats and sizes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. Although less common, wire bonding can be used to connect an ic to other. The pad consists of a bonding pad an area to which the bond wire is soldered. For the last 15 years, quikpak has provided fast turn ic packaging, assembly, prototype and wafer processing services to a wide variety of semiconductor and. Tape carrier package assembly process flow in parallel with the bumping process, tab tape sites are manufactured in reeltoreel format. The length of the wire bond determines the total impedance, capacitance, and inductance of the connection.
Typical bond pad metallization consists of aluminum with1% silicon and 0. Semiconductor assembly packaging testing and packing. Fully processcompatible layout design on bond pad to. Mechanical and thermal design guidelines lidless flipchip packages the xilinx lidless flipchip ball grid array bga packages use the same package substrate. Corrosion mechanism of cu balls and al pads at a initiation and b propagation stage at 5 min soaking time. Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. The dimensions given in figures 3 and 4 relate to the f60 process. Package details soic8 case central semiconductor corp. The wire is placed in direct contact with the bonding tool and the bond pad. Ieee electronics packaging society, scv chapter september 28, 2017. Amkor is an industry leader in finding ic packaging solutions to meet complex requirements.
Mechanical drawing mounting pad geometrydimensions in mm lead code. Esd electrostatic discharge protecting circuitry consisting of a pair of big pmos, nmos. A semiconductor package is a metal, plastic, glass, or ceramic casing containing one or more discrete semiconductor devices or integrated circuits. By descending the wedge onto the ic bond pad, the wire is pinned against the pad surface and an us or ts bond is performed. Ic bond pad structures having al metallization and sio. About ic knowledge ic knowledge was founded in the year 2000 by a group of wafer fabrication technologists and management specialists. Printed circuit board assembly recommendations for. Gold ball or gold wedge gold wire bonded to an aluminum pad is the most used wire bonding process in the semiconductor industry for ic packaging.
Recent industry survey shows that about 90% of all electronic packages and assemblies are produced using ball bonds and about 10% are produced with wedge bonds. Use of harsh wire bonding to evaluate various bond pad. Corrosion study and intermetallics formation in gold and. Wire bonding all pads are around chip edges 100um pitch. To meet such diverse range of requirements, ic package. Bond pad metallurgy the type and cleanliness of the aluminum bond pad metallization are important factors to be considered in forming this first wire bond. An2409, small outline integrated circuit soic package.