MRSI was founded in Massachusetts in 1984 with the goal of providing automated solutions for dispense and assembly of microelectronic devices.
MRSI develops, manufactures and markets high precision, fully automatic assembly and dispense systems.
Our customers use our systems to assemble electronic packages, which are comprised of bare chips and some attachment material.
Our customers are mostly in the following microelectronics markets:
Aerospace and defense (hybrids, imaging, sensing), Telecom/Datacom (microwave and RF, photonics, TOSA/ROSA, AOCs), Industrial, life & health sciences, and computing
We are dedicated to deliver high quality and cost-effective systems that create value for our customers. In our effort to achieve this mission, we strive to provide uncompromising benefits and satisfaction to our customers, vendors, employees.
Die Bond & Dispense
MRSI’s current product portfolio consists of configurable die bonding and epoxy dispensing tools catering to the precision end of the electronics assembly market. Capable of placement accuracies ranging from 3 micron (“μm”) to 10µm, the Company’s family of automated die bonders exceeds the industry standard for die attach in complex advanced packaging applications. MRSI’s die bonding tools are built on a common platform that is configured to meet specific customer requirements, allowing the Company to provide the most flexible automated assembly systems available for applications necessitating both extreme accuracy and throughputs up to 1,000 placements per hour
MRSI’s epoxy dispensers have the capacity to repeatedly dispense dots, lines and areas and stamp dots as small as 0.004” (four thousandths of an inch) and operate on the same Windows-based software that controls the Company’s other products. MRSI’s tools leverage a well-defined set of core competencies in system design, software development, machine vision, motion control, industrial automation and optical design expertise.
RF & Microwave Assembly
Manufacturers of microwave modules, RF circuits, MEMS, advanced semiconductor packages, multi-chip modules, hybrid devices are the original “core” customers for the MRSI products. The hardware and software for the die bond and dispense platforms were designed around the needs for greater accuracy and repeatability in the assembly of complex microwave and RF assemblies. These systems require continuously higher integrated and cost effective RF components, but keeping the same level of excellent RF characteristics. Millimeterwave frequencies require more and more a new generation of GaAs-MMICs which are today only 50µm thick for lower via inductances to ground and a lower thermal resistance. Attach of those MMICs by use of conductive adhesive is the cheapest approach but requires a high performance epoxy dispense process in order to control smallest dispense volumes in the range of 1 nanoliter. The adhesive volume has to be carefully predicted according to each MMIC’s size. Delicate issues are a final bondline thickness after attach of 5-10 micron (thermal conditions) and a well controlled epoxy fillet at the chip edges (epoxy squeezes out during pick & place). A +/-10% volume control means a fillet variation between 0 and 100% of the MMIC height. A pattern drawback from the edge of the MMIC can’t be allowed at millimeterwave frequencies (RF current flow). This requires extremely accurate control of the bond force.
Today’s electronic package manufacturers are faced with progressively challenging applications as product miniaturization, power, circuit frequency and complexity increase. Shorter product cycles minimize the time available to ramp to volume production. Advanced microelectronic packaging for Microwave, Hybrids, MEMs and Photonics is considered to be among the most challenging of dispense applications.
Advances in the automated dispensing of conductive epoxy have enabled the microelectronics industry to take better advantage of automation even as the products have become more challenging to produce. The manufacturing of microelectronic circuits is typical of the extreme control needed for today’s advanced packaging. The primary concern of design and process engineers is epoxy control. Bond lines must be controlled to ensure good thermal properties. Squeeze out must be controlled to prevent shorting or bridging. Placement accuracies must be controlled in order for high frequency components to operate properly. Full epoxy coverage with no voiding is important to maximize thermal transfer and minimize stresses. Automated equipment must be capable of all this at a minimum and then also be fast, reliable and repeatable.
The MRSI-175Ag can be configured with multiple pumps or a mix of pumps, jetting and stamping tools. Two pumps can be used for two different epoxies simultaneously. Or a pump and a stamping tool with a tool changer can be used to dispense one epoxy and stamp small dots and a second epoxy. Ultimately, when the pumps and stamping tools are attached with a common mount and can be changed over quickly, the best flexibility is achieved.
Eutectic Die Bonding
The term “eutectic” is from the Greek word eutektos, meaning “easily melted.” It is defined as the temperature and percent mixture (point “E” on Figure 2) where it will go directly from pure solid to pure liquid, just like a pure metal would. Any point on the phase diagram above the line “AEB” is above the eutectic temperature and is referred to as the “liquidus” state, i.e., where the mixture is 100 percent liquid.1
Pulse Heat Profiling
Pulse heat profiling is a method of applying a controlled temperature with a time-varying profile to a substrate. The information (bonding profile) is typically entered through a graphical user interface, and the temperature vs. time can be displayed and tracked using a closed-loop feedback system. Time is an important element in the profile because there must be sufficient time for the solder to wet and spread around the joint through capillary action referred to as “wicking.”
Pulse heat profiling is a good method for heating substrates with low thermal mass (typically ceramic or alumina substrates less than 1 cm2). Using parts with low thermal mass permits rapid temperature ramp times (faster than 50°C per second), which minimizes wait time between eutectic bonds and maximizes throughput.
High Accuracy Thermo-compression Flip Chip Die Bonding
(Beyond C4 Process)
Faced with the significant costs of scaling integrated circuit manufacturing technology to sub-20nm line widths, the semiconductor industry is turning to packaging innovations to achieve ongoing performance and power consumption improvements in continued pursuit of Moore’s Law. In particular, the stacking of integrated circuits to form 2.5D/3D packages is rapidly emerging as the most effective path forward for suppliers of digital integrated circuits such as memory, logic and FPGAs. By 2017, over 9.0% of all integrated circuits produced globally are expected to incorporate some form of multi-level stacking technology.
The vertical stacking of dies was introduced over two decades ago, notably with the implementation of SiP form factors. However, contemporary 2.5D packages incorporate a key innovation in the form of silicon interposers embedded with TSVs that act as electrical channels between substrates and bare dies. More specifically, TSVs connect the metallization on an interposer’s upper and lower surfaces, allowing dies to communicate horizontally across the interposer. Micro-bumps of approximately 10µm in diameter are then used to attach the die to the interposer; in turn, the interposer is attached to the substrate with regular flip chip bumps in the order of 100µm. The advantages of 2.5D packages relative to 2D packages include dramatic improvements in capacity and performance as well as improvements in production yield. 2.5D technology is generally viewed as an intermediary step to full 3D implementation, which is expected to become mainstream beginning in 2015 for select applications.
In 3D integrated circuits, two or more dies are mounted vertically. These structures rely on extremely thin dies, resulting in various mechanical and thermal complications when dies are packaged during the assembly processes. Thermal compression bonding, the methodology underpinning MRSI’s TCB system for 2.5D/3D packaging, is poised to surpass C4 processes due to superior yield and cost benefits.
Active Optical Cable Assembly & Silicon Photonics
AOC technology is a cabling methodology that accepts the same electrical input as traditional copper cables, but utilizes optical fiber between the connectors. AOCs use electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. The basis of AOCs is to embed the active optical transceiver components into the electronic connector instead of using separate optical transceiver and pluggable fiber cable. AOC assemblies are expected to replace legacy copper technology in data centers and high performance computing applications, enabling data to be transmitted at higher bandwidths over longer distances while occupying less physical space. Copper cables remain heavy and bulky, difficult to physically manage, and are prone to limitations in performance and reliability due to electromagnetic interference (“EMI”).
Active optical cables and their applications in the data center stem from technological advances in silicon photonics. Silicon photonics is an evolving technology in which data is transferred among computer chips via optical rays. Optical rays, in comparison to traditional electrical conductor technologies, can carry exponentially more data in less time. Silicon photonics involves combining laser and silicon technology on the same chip, blending optical technology with low cost CMOS semiconductor processing. Improved performance thus results from greater available bandwidth and higher propagation speed of infrared beams compared with electric current. This technology is being actively researched by electronic manufacturers including IBM and Intel as a means of keeping on track with Moore’s Law by using optical interconnects to provide faster data transfer both between and within microchips.
Thermal and Misc. Attach Methods