Technical Library | 2023-01-17 17:12:33.0
Reflowed indium metal has for decades been the standard for solder thermal interface materials (solder TIMs or sTIMs) in most high-performance computing (HPC) TIM1 applications. The IEEE Heterogeneous Integration Thermal roadmap states that new thermal interface materials solutions must provide a path to the successful application of increased total-package die areas up to 100cm2. While GPU architectures are relatively isothermal during usage, CPU hotspots in complex heterogeneously-integrated modules will need to be able to handle heat flux hotspots up to 1000W/cm2 within the next two years. Indium and its alloys are used as reflowed solder thermal interface materials in both CPU and GPU "die to lid/heat spreader" (TIM1) applications. Their high bulk thermal conductivity and proven long-term reliability suit them well for extreme thermomechanical stresses. Voiding is the most important failure mode and has been studied by x-ray. The effects of surface pretreatment, pressure during reflow, solder flux type/fluxless processing, and preform design parameters, such as alloy type, are also examined. The paper includes data on both vacuum and pressure (autoclave) reflow of sTIMs, which is becoming necessary to meet upcoming requirements for ultralow voiding in some instances.
Technical Library | 2023-01-17 17:27:13.0
Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The degree of wetting, the microstructure (in particular the intermetallic layer), and the inherent strength of the solder all factor into the reliability of the solder joint. This paper presents experimental results on the effect of reflow profile on both 63%Sn 37%Pb (SnPb) and 96.5%Sn 3.0%Ag 0.5%Cu (SAC 305) solder joint shear force. Specifically, the effect of the reflow peak temperature and time above solder liquidus temperature are studied. Nine reflow profiles for SAC 305 and nine reflow profiles for SnPb have been developed with three levels of peak temperature (230 o C, 240 o C, and 250 o C for SAC 305; and 195 o C, 205 o C, and 215 o C for SnPb) and three levels of time above solder liquidus temperature (30 sec., 60 sec., and 90 sec.). The shear force data of four different sizes of chip resistors (1206, 0805, 0603, and 0402) are compared across the different profiles. The shear force of the resistors is measured at time 0 (right after assembly). The fracture surfaces have been studied using a scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS)
Technical Library | 2023-08-16 18:20:44.0
One of our defense customers planned to dispense underfill material for small and large die, using Hysol FP4545FC epoxy encapsulant. This process dissipates stress on solder joints and prevents cracking and fracturing between the bottom of the die and the surface of the substrate.
Technical Library | 2024-02-02 07:48:31.0
Maximizing Efficiency: The High-Speed SMT Line With Laser Depanelizer In today's rapidly evolving electronics manufacturing landscape, optimizing efficiency, cost-effectiveness, and precision remains paramount. Businesses engaged in producing industrial control boards, computer motherboards, mobile phone motherboards, and mining machine boards face ongoing challenges in streamlining production processes. The integration of expensive equipment strains budgets, making the creation of an efficient, cost-effective high-speed SMT line a daunting task. However, a solution exists that seamlessly combines these elements into a singular, high-performance, and cost-effective SMT line. Let's delve into the specifics. A Comprehensive High-Speed SMT Line Our innovative solution amalgamates two pivotal components: a cutting-edge SMT (Surface Mount Technology) production line and a laser cutting line equipped with a depanelizer. The SMT Production Line The high-speed SMT line comprises several essential components, each fulfilling a unique role in the manufacturing process: 1. PCB Loader: This initial stage involves loading boards onto the production line with utmost care. Our Board Loader prioritizes safety, incorporating various safety light curtains and sensors to promptly halt operations and issue alerts in case of any anomalies. 2. Laser Marking Machine: Every PCB receives a unique two-dimensional code or barcode, facilitating comprehensive traceability. Despite the high-temperature laser process potentially leading to dust accumulation on PCB surfaces, our dedicated PCB Surface Cleaner swiftly addresses this issue. 3. SMT Solder Paste Printer: This stage involves applying solder paste to the boards, a fundamental step in the manufacturing process. 4. SPI (Solder Paste Inspection): Meticulous inspections are conducted at this stage. Boards passing inspection proceed through the NG (No Good) Buffer Conveyor to the module mounters. Conversely, "No Good" results prompt storage of PCBs in the NG Buffer Conveyor, capable of accommodating up to 25 PCBs. Operators can retrieve these NG boards for rework after utilizing our specialized PCB Mis Cleaner to remove solder paste. 5. Module Mounters: These machines excel in attaching small and delicate components, necessitating precision and expertise in the module mounting process. 6. Standard Pick And Place Machines: The selection of these machines is contingent upon your specific BOM (Bill of Materials) list. 7. Pre-Reflow AOI (Automated Optical Inspection): Boards undergo examination for component quality at this stage. Detected issues prompt the Sorting Conveyor to segregate boards for rework. 8. Reflow Oven: Boards undergo reflow soldering, with our Lyra series reflow ovens recommended for their outstanding features, including nitrogen capability, flux recycling, and water cooling function, ensuring impeccable soldering results. 9. Post-Reflow AOI: This stage focuses on examining soldering quality. Detected defects prompt the Sorting Conveyor to segregate boards for further inspection or rework. Any identified defects are efficiently addressed with the BGA rework station, maintaining the highest quality standards. 10. Laser Depanelizer: Boards advance to the laser depanelizer, where precision laser cutting, often employing green light for optimal results, ensures smoke-free, highly accurate separation of boards. 11. PCB Placement Machine: Cut boards are subsequently managed by the PCB Placement Machine, arranging them as required. With this, all high-speed SMT line processes are concluded. Efficiency And Output This production line demonstrates exceptional productivity when manufacturing motherboards with approximately 3000 electronic components, boasting the potential to assemble up to 180 boards within a single hour. Such efficiency not only enhances output but also ensures cost-effectiveness and precision in your manufacturing processes. At I.C.T, we specialize in crafting customized SMT production line solutions tailored to your product and specific requirements. Our equipment complies with European safety standards and holds CE certificates. For inquiries or to explore our exemplary post-sales support, do not hesitate to contact us. The I.C.T team is here to elevate your electronics manufacturing to new heights of efficiency and cost-effectiveness.
Technical Library | 2007-02-01 09:36:26.0
Purpose: Compare the Surface Insulation Resistance of reworked BGA Test samples made with standard solder balls using a flux only reattachment and samples made including the StencilQuik™ product from Best Inc. with solder balls using a flux only reattachment.
Technical Library | 2022-10-31 17:25:37.0
Mixed formulation solder alloys refer to specific combinations of Sn-37Pb and SAC305 (96.5Sn–3.0Ag–0.5Cu). They present a solution for the interim period before Pb-free electronic assemblies are universally accepted. In this work, the surfaces of mixed formulation solder alloys have been studied by in situ and real-time Auger electron spectroscopy as a function of temperature as the alloys are raised above the melting point. With increasing temperature, there is a growing fraction of low-level, bulk contaminants that segregate to the alloy surfaces. In particular, the amount of surface C is nearly _50–60 at. % C at the melting point. The segregating impurities inhibit solderability by providing a blocking layer to reaction between the alloy and substrate. A similar phenomenon has been observed over a wide range of (SAC and non-SAC) alloys synthesized by a variety of techniques. That solder alloy surfaces at melting have a radically different composition from the bulk uncovers a key variable that helps to explain the wide variability in contact angles reported in previous studies of wetting and adhesion. VC 2011 American Vacuum Society. [DOI: 10.1116/1.3584821]
Technical Library | 2013-01-24 19:16:35.0
The electronics industry has mainly adopted the higher melting point Sn3Ag0.5Cu solder alloys for lead-free reflow soldering applications. For applications where temperature sensitive components and boards are used this has created a need to develop low melting point lead-free alloy solder pastes. Tin-bismuth and tin-bismuth-silver containing alloys were used to address the temperature issue with development done on Sn58Bi, Sn57.6Bi0.4Ag, Sn57Bi1Ag lead-free solder alloy pastes. Investigations included paste printing studies, reflow and wetting analysis on different substrates and board surface finishes and head-in-pillow paste performance in addition to paste-in-hole reflow tests. Voiding was also investigated on tin-bismuth and tin-bismuth-silver versus Sn3Ag0.5Cu soldered QFN/MLF/BTC components. Mechanical bond strength testing was also done comparing Sn58Bi, Sn37Pb and Sn3Ag0.5Cu soldered components. The results of the work are reported.
Technical Library | 2024-02-05 17:51:01.0
Objective: Drying = reducing the humidity in PCB before soldering Preventing delamination caused by thermal stress after moisture absorption Methods: Drying in convection and/ or vacuum oven Parameters subject to material type, soldering surface, layer count, time to soldering, layout (copper-plated areas)
Technical Library | 2021-07-06 21:13:36.0
The surface finishes commonly used on printed circuit boards (PCBs) have an effect on solder paste performance in the surface mount process. Some surface finishes are non-planar like hot air solder level (HASL) which can lead to inconsistencies in solder paste printing. Other surface finishes are difficult to wet during reflow like organic solderability preservative (OSP). What is the overall effect of surface finish on solder paste performance? Which solder paste is best for each surface finish? It is the goal of this paper to answer these questions.
Technical Library | 2020-07-29 20:12:52.0
Aluminum is a metal that it is hard to solder due to the high surface tension difference between it and molten solder alloy. This occurs because aluminum rapidly forms a tenacious oxide layer whenever it is exposed to oxygen in the air. The oxide layer is responsible for the high surface tension difference between the aluminum and the solder and impedes the solder from spreading evenly on an aluminum surface. There are hundreds of aluminum alloys available in the marketplace; it is important to identify the form of aluminum that is being soldered. Once this is done, an appropriate soldering technique can be chosen for soldering the specific aluminum alloy under consideration. Direct aluminum soldering eliminates using expensive plating techniques to prepare the aluminum surface for soldering.
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