Automotive as automotive electronics become increasingly sophisticated and widespread, the demand for reliable, high. Thermally conductive flipchip underfill materials with ultra high glass transition temperature. Moreover, voids in the underfill do not have enough density variation for an easy detection. Physics of failure analysis of xilinx flip chip ccga packages. Underfill ff35s excellent capillary action forms a thin bond line and complete spread. Underfill material surrounding passive components has not been found to have a deleterious effect. Jetting underfill as well as other semiconductor packaging fluids is a paradigm shift in the. Improper thermal management and heat dissipation can result in dramatic failure in high performance computers while the functional aspects of the typical dieattach, component attach, substrate attach and thermal management are the same for all electronics, managing the ever evolving cpu and gpu dieattaches for power thermal management and stacking of large area chips for memory modules.
This underfill process is being used in production for chiponwafer and chiponbga packaging. Wusheng yin and mary liu, underfill for ultralow bumped 10u 3d tsv package in. Comparative study of different underfill material on flip. Underfill ff35 is a low surface tension, one component epoxy resin designed for use as a capillary flow underfill for flip chip, csp, bga and ubga assemblies. For more information and recommendation assistance, please contact ait. Nepp studies on the reliability of flip chip solder joints.
Higher io counts, package integration, and tighter bump pitches are dictating the use of flipchip technology to enable advanced package designs. Interactions between variable frequency microwave underfill. Six underfill materials were examined for the selection of an appropriate. In the case of underfill, the resin has a very low density compared to boards and components. Pdf comparative study of different underfill material on. High flow at low curing temperature of 100150c to achieve lower internal stresses. Control of the underfill of surface mount assemblies by non. Wusheng yin and mary liu, a low cost and high thermal conductive solderable adhesive in long beach, california, imaps, october 9, 2011 2.
In high volume commercial applications, the use of 10to20m dieattach film adhesive. High flow at minimal pressure of less than 2 psi for flowoverwire for stackchip encapsulation and bonding. Alpha hitech cu312030 is a onecomponent capillary underfill designed for the protection of assembled chip packages onto printed circuit boards. Ait has created a unique underfill chemistry that offers ultimate temperature. Finding the right underfill by analysis is very difficult. Underfill specific material requirements for high reliability and spacerelevant. All measured mechanical properties met requirements for a good underfill for both terrestrial and space applications. Advances in fast underfill of flip chips abstract introduction satech. Yincae advanced materials, llc has developed a novel high thermal conductive underfill for flip chip applications. It is recommended that the underfill should at least cover 60 to 100um higher than the dicing defects region.
Precise, highthroughput underfill dispense in chipon. A novel high thermal conductive underfill for flip chip application dr. Silicon dioxide is normally used as filler in underfill. Jun 17, 2020 fatigue delamination of underfill, causing solder joint failure. For underfill or encapsulation applications in electronics that require strong bonding and toughness. Crosscapillary action from adjacent chips or passive components that pull the underfill material away from the intended device can result in voids under the csp or flip chip. For more information and recommendation assistance, please contact ait sales and engineering. Importantly, the novel underfill exhibits high glass transition tg temperature capability of 155c.
The dimension of the hicte ceramic substrate was 33. Underfill material for flip chip and other micropackages draft 7 underfill adhesives for flip chip applications task group 524f table of contents drafted by ipc print page 2 thru 23 for draft 7 of jstd030 2215 sanders road, print page 24 thru 24 for minutes of meeting september 2000 northbrook, il 60062 phone. Moisture related reliability in electronic packaging. Compared to 3811 underfill, 1a underfill gives lower. The flip chip package during the underfill curing process is very flat, i. Jetting of underfill and encapsulants for highspeed. Quantification of underfill influence to chip packaging. High operating temperature underfill for electronics. The normal cte data for this type of underfill material are 63, 70, and 75 ppmc. Guideline for selection and application of underfill material. In one example, underfill must be dispensed within 300500um koz of.
Development of reworkable underfill encapsulants for high speed processing for high volume mobile phone production, reufa is too timeconsuming to rework. This new chiponwafer underfill application created opportunities for automatic high speed precision dispensing. Nasa outgassing compliant nasaesa outgassing qualified products test procedures. Underfill and globtop encapsulation with high glass. In this research, an innovative dispenseless fluxing underfill process and the associated module have been developed to achieve high speed smt compatible underfill processing 1. New generation underfills alpha assembly solutions. In this paper, we will examine the criteria for higher efficiency, more reliability and higher.
There were three different fillet height 50%, 75% and 100% and five diff erent fillet width 0. Introduction jetting of epoxies and other materials is going to change the way people do dispensing. High tg, low cte underfill alpha hitech cu312030 is a onecomponent capillary underfill designed for the protection of assembled chip packages onto printed circuit boards. Ai technology is a pioneer in the microelectronic materials industry and developed. Jul 28, 2014 ai technology is proud to introduce a new generation of flipchip underfill solution that combines a high tg of 240c and novel stress. Enabling high density system in package sip manufacturing. Guideline for selection and application of underfill. Loctite eccobond uf 1173 is a onecomponent underfill that can be jet or needle dispensed, flows fast in and around tight interspaces and cures quickly to form voidfree interconnect protection from shock, drop and vibration. High material module underfill has excellent thermalcycle performance, good protection for solderjoints and pad connections, and good antipeeling strength for. Underfill ff35 enhances reliability with a high tg, low cte, and excellent adhesion.
Join laminate to interposer underfill 1 join top chip to interposer underfill 2 bga sac attach module test underfill top chip interposer top chip ubm c4 sac solder cu pads sac solder. High temperature underfill is to be dispensed onto two adjacent sides of the chip to be underfill. Study of capillary underfill filler separation in advanced. Enhanced capillary flow action with temperatures of 4060c following with curing at temperatures of 150200c. High performance flip chip plastic ball grid array fcpbga packages continue to push the envelope with. High cte ucu pillar c4 sac solder cuni au pads niau or cu osp underfill 5x reflows underfill 5x reflows laminate ball grid array bga c4 possible assembly. The underfill is usually cured at a high temperature, such as 165 c. Control of the underfill of surface mount assemblies by. A tin cap is deposited over the high melting high lead bump to provide low temperature soldering while maintaining a standoff. Underfill and globtop encapsulation ai technology, inc. Bond to pbt, pps, nylon, pc, phenolics and other difficult materials. Underfills and globtops proven to perform at temperatures.
Underfill, solder joint reliability, thermal cycle, mechanical fatigue, drop. Figure 1b where w is underfill fillet width and h is underfill f illet heig ht. Precise, highthroughput underfill dispense in chiponwafer. Enabling high density system in package sip manufacturing and consumer electronic devices through the use of jetting technology to minimize substrate area for underfill michael peterson belton technology, inc. Ipc 3000 lakeside drive, suite 309s bannockburn, il 600151249. Enabling high density system in package sip manufacturing and consumer electronic devices through the use of jetting technology to minimize substrate area for underfill michael peterson director advanced engineering belton technology, inc. Adding underfill to these products helps to enhance the performance of these precision pieces and allows manufactures to maintain a high level of quality. Underfill has also been successfully used on chip scale packages csps to increase their reliability 8. A novel high thermal conductive underfill for flip chip. An innovative underfill process for highspeed snit cspbga.
Selection and application of board level underfill materials. Greg allen, chief of strategy and communications joint artificial intelligence center jaic department of defense. Ait brochure of insulated metal thermal substrate ai technology. Tg 240c to ensure minimal stress during reflow soldering. If that wasnt enough, intel also announced that it is bundling the design with the latest high bandwidth memory, hbm. Ait has created a unique underfill chemistry that offers ultimate te. C stages 23 110 50 1120 75 2 100 3140 x y z hot plate translation stage. Wusheng yin yincae advanced materials, llc albany, ny abstract. Jan 27, 2011 high material module underfill has an extremely low cte, for instance underfill a cte 63 ppmc. Organic c4 and cu pillar can be as reliable or more reliable than class y, if right underfill material is used with good workmanship. Therefore the increase of thermal conductivity of underfill can significantly enhance the reliability of electronic devices, particularly in 3d package devices. A high precision, high throughput underfill dispensing process has been developed to conquer these challenges. For successful flipchip packaging, the flipchip underfill must also perform as a. Ieeeeps chapter lecture in the silicon valley area fanout.
Underifll a, b, c were provided from varied vendors, and the underfill material d, e, f were provided by h. An investigation was conducted characterizeto the solder joint integrity of high io bga connector technologies under ipc class 3 thermal cycle conditioning. This paper will describe the work done to develop a jet capable of dispensing abrasive underfill materials, producing smaller fillets and high throughput. Advanced organic substrate technologies to enable extreme. Advanced insulating film for nextgeneration smartphone. Automotive as automotive electronics become increasingly sophisticated and widespread, the demand for reliable, high performance components has grown. Due to the flow of underfill, if the flow front is not uniform, underfill could flow faster in some areas, thus c apturing voids, termed as capture voids. Aits underfills have the unparalleled ability to manage stress while providing an outstanding moisture barrier. Introduction after years of development, underfill encapsulant materials and their related processes remain critical enablers for high end, highly stressed advanced flip chip packages. Over view of the ajinomoto group as of march 31, 2017 foundation paidin capital net sales fy2017 may 20, 1909 jpy 79,863million number of employee 34,452 jpy 1,150. After all the boards were assemblied, 6 types of underfill materials were applied to improve the component and board reliability. For many materials at high xray energies, the xray attenuation length can be very long, resulting in little xray absorption and therefore poor imaging contrast. Non hermetic ceramic flip chip package construction and.
A nonconnector comobvious effect is how these high density connectors impact assembly producibility and solder joint integrity. Underfill material selection for flip chip technology by. Yincae advanced materials, llc has developed a novel high thermal conductive underfill for. The underfill adhesive must not prevent contact when the chip and package. To achieve easier rework, tg was reduced to 70c so that encapsulant and components could be easily removed at elevated temperatures.
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