Technical Library | 2019-06-07 14:49:54.0
ACI Technologies was contacted in regards to poor solder joint reliability. The customer submitted an assembly that was exhibiting intermittent opens at multiple locations on a ball grid array (BGA) component. The assembly’s functionality did not survive international shipping, essentially shock and vibration failures, immediately making the quality of the solder joints suspect. The customer was asked about the contract manufacturer and the reflow oven profile as well as the solder paste and surface finish used. The ACI engineering staff evaluated the contract manufacturer’s technique and determined that they were competent in the methods they used for placing thermocouples in the proper locations and developing the reflow oven profile. The surface finish was unusual, but not unheard of, in that it was hard gold over hard nickel, rather than electroless nickel immersion gold (ENIG). The customer was able to supply boundary scan testing data which showed a diagonal row of troublesome BGA pins.
Technical Library | 2020-07-01 19:45:04.0
A company approached ACI Technologies (ACI) for assistance with a new product that was about to undergo its initial proof-of-concept prototype build. This product was an item that was being furnished to the Department of Defense for a program designed to increase the technical capabilities of computer equipment issued to the war fighter. The requirements for this item specified the use of tin-lead solder during assembly of production units. One of the main responsibilities for ACI during this project was to assist the client in mitigating the risk introduced using commercial off-the-shelf materials that may be lead-free.
Technical Library | 2020-11-09 16:59:53.0
A customer contacted ACI Technologies regarding a high failure rate of their assemblies. They provided assemblies to be X-rayed and inspected for the purpose of identifying any process related issues such as (but not limited to) solder and assembly workmanship and evidence of damage due to moisture related problems during reflow (a.k.a. "popcorning"). Moisture damage usually appears as physical damage to the component. The first indication of moisture damage would be externally observable changes to the package in the form of bulging or fractures to the outer surface of the component, an example of which is shown in Figure 1. Internally observable indicators of moisture damage typically include fractures to the die inside the package and lifted or fractured wire bonds. These conditions would be apparent during transmissive X-ray inspection. Another symptom of moisture related damage would be inconsistent solder joint sizes that result from package deformation during the liquidus phase of the reflow process. None of these indicators of moisture related damage were present on the customer samples.
Technical Library | 2023-12-06 03:28:49.0
Mastering Precision: I.C.T's SMT Conformal Coating Valves Introduction Of SMT Conformal Coating Valves: In various industries, including electronics, lighting, energy, and life sciences, the SMT conformal coating process plays a critical role. Precision is key, and the choice of a SMT coating valve significantly influences application quality. This article explores I.C.T's SMT conformal coating valves, focusing on the C-0101, C-L101, PJ-01, PJ-01 (with plastic bucket), C-0100, D-0100, D-0300, and the W Series. C-0101 Water Curtain Spray SMT Conformal Coating Valves: The C-0101, a non-atomizing water curtain spray valve, excels with low-viscosity solvent materials. It ensures clean and precise edges in applications like conformal coatings, UV adhesives, backfilling, and volatile substances. C-L101 Rotary Water Curtain Spray Valve: Similar to the C-0101, the C-L101 suits low-viscosity solvent materials, offering a precise edge without splashing for various coatings. PJ-01 Injection Valve (Without Plastic Bucket): Designed for high-precision applications in electronics, lighting, energy, and life sciences, the PJ-01 excels in accurate dispensing and coating. It accommodates various materials, including red glue, liquids, and pastes. PJ-01 Injection Valve (With Plastic Bucket 30CC): The PJ-01, with a 30cc plastic bucket, maintains high precision for complex circuit board applications, offering precise dispensing for materials like red glue, liquids, and pastes. C-0100 Non-Rotating Film Valve: Different from pneumatic atomizing valves, the C-0100 provides precise edge definition without air pressure involvement. It addresses issues related to atomizing drift and fast-drying adhesives, allowing control over the film width. D-0100 Precision Valve: The D-0100, with a unique fluid-sealing structure driven by compressed air, minimizes seal replacement frequency. Suitable for various fluid dispensing, it handles UV adhesives, encapsulating materials, silicones, epoxies, and surface coatings. D-0300 Dispensing Valve: Tailored for precision fluid dispensing at low driving pressure, the D-0300 accommodates a range of materials, including acrylics, silicones, epoxies, and UV adhesives. It's ideal for applications where accuracy and consistency are crucial. W Series: Needle Design Atomization Valves: The W Series offers needle design valves leaving zero residue. Easy to clean without disassembly, they provide adjustable fluid and air pressure for various coating materials, ensuring excellent atomization effects. Analyzing The Options: When selecting a conformal coating valve, consider specific application requirements. C-0101 and C-L101 suit low-viscosity solvent materials, providing clean and precise edges. PJ-01, with or without a plastic bucket, offers high-precision dispensing for complex applications. C-0100 and D-0100 are versatile for various materials, and D-0300 excels in precision dispensing. The W Series offers residue-free needle design atomization valves. Choose based on material, precision, and coating needs. Integration with I.C.T's Conformal Coating Machines: Integral to I.C.T's Conformal Coating machines, these valves enable precise application tailored to specific requirements. Machines like I.C.T-T550, I.C.T-T550U, I.C.T-T600, and I.C.T-T650 come equipped with a range of valve options catering to diverse production line needs. I.C.T SMT Coating Machine.png Conclusion: Selecting the right conformal coating valve is crucial for consistent, high-quality results. Evaluate options based on material, precision, and coating requirements. I.C.T provides tailored solutions for electronic assembly needs. For detailed insights into coating and dispensing machines, follow the provided link. Professional engineers are ready to assist in designing a production line that perfectly matches your requirements, ensuring optimal performance. Contact us for more information and tailored solutions to elevate your conformal coating processes.
Technical Library | 2007-08-16 13:34:31.0
While experienced inspectors may be able to determine the aesthetic differences between a lead-free PCB assembly and a tin-lead version, one cannot rely on the "experienced eye". "Less wetting out to the pad edges" (Figure A) and "graininess and lack of shininess of the solder joint" (Figure B) are typical comments about some lead-free solder joints. However, in cases where a Nitrogen atmosphere was present during the reflow of the solder joint (Figure C), there will be little visual differences between the lead free alloys and their tin-lead counterparts.
Technical Library | 2007-02-01 09:57:15.0
The rapid assimilation of Ball Grid Array (BGA) and other Area Array Package technology in the electronics industry is due to the fact that this package type allows for a greater I/O count in a smaller area while maintaining a pitch that allows for ease of manufacture.
Technical Library | 2007-06-21 17:03:16.0
The rapid assimilation of Ball Grid Array (BGA) and other Area Array Package technology in the electronics industry is due to the fact that this package type allows for a greater I/O count in a smaller area while maintaining a pitch that allows for ease of manufacture (...) While there have been several studies comparing these two attachment methods, this study highlights the effect of rework technique on the electrical characteristics and reliability of reworked BGAs.
Technical Library | 2019-05-29 23:10:30.0
There are times when a PCB prototype needs to be built quickly to test out a design. In such cases where it is known early on that there will be multiple iterations or that a "one and done" assembly will be made that there will be some SMT assemblers who choose to hand print solder paste onto the board using a "frameless" stencil. In such cases where hand printing is used, the consistency of the printing technique has typically been in question. Furthermore, the effectiveness of both the nanocoatings as well as the higher end stainless steel materials, which have been heretofore studied in controlled printing environments, will be evaluated for their impact on the hand printing process.The purpose of the study was to determine the effectiveness of select nanocoating materials as well as certain high end stainless steel stencil materials as they relate to the manual SMT printing process. A variety of nanocoatings were applied to SMT metal stencils and solder paste volume measurements were taken to compare the effectiveness.
Technical Library | 2020-04-16 05:52:45.0
Based on the dual pot, we developed an independent dual z-axis control dual pot for FLEX-i2! There are 5 operation modes available with the independent dual Z axis: only solder pot1, only solder pot2, first solder pot 1 then solder pot2, first solder pot2 then solder pot1, solder pot1 and solder pot2 together. In specific applications, solder pot1 can be selected with large nozzle soldering heat-absorbing large parts, solder pot2 use small nozzle soldering heat-absorbing small parts, so as to achieve both soldering effect and productivity. Also can use same nozzle, dual axis simultaneously solder two same plate to increase productivity. To get the maximum flexibility and productivity! FLEX-i2 is a compact in line selective soldering machine, equipped with high precision servo control system, jet valve, live-on camera, upper preheating etc, which can provide a high flexibility and efficiency soldering process. The maximum soldering size can reach 420mm*490mm!
Technical Library | 2022-12-23 20:44:54.0
One of the upcoming reliability issues which is related to the lead-free solder introduction, are the headin-pillow solderability problems, mainly for BGA packages. These problems are due to excessive package warpage at reflow temperature. Both convex and concave warpage at reflow temperature can lead to the head-in-pillow problem where the solder paste and solder ball are in mechanical contact but not forming one uniform joint. With the thermo-Moiré profile measurements, this paper explains for two flex BGA packages the head-in-pillow. Both local and global height differences higher than 100 µm have been measured at solder reflow temperature. This can be sufficient to have no contact between the molten solder ball and solder paste. Finally, the impact of package drying is measured
