Technical Library | 2020-09-02 14:34:23.0
Atomic layer deposition (ALD) is a process of creating coatings on a molecular layer by layer basis. Using an iterated sequence of self-saturating deposition cycles that are self-terminating, a single layer can be deposited at a time, allowing for highly uniform films with complete conformality. The composition of the film typically used for coating printed wiring boards (PWBs) is a high alumina (Al2O3) sequential deposition of alumina and titania capped with a corrosion protective titanium aluminate layer, most notably ALD-Cap from Sundew Technologies, LLC. Rework is a process of restoring an electronics assembly to full functionality to prolong equipment life and reduce the amount of scrap. The process typically involves:
Technical Library | 2019-10-21 09:58:50.0
An ACI Technologies customer inquired regarding printed circuit board(PCB) failures that were becoming increasingly prevalent after the SMT (surface mount technology) manufacturing process. The failures were detected by electrical testing, but were undetermined as to the location and specific devices causing the failures. The failures were suspected to be caused predominately in the BGA (ball grid array) devices located on specific sites on this 16 layer construction. Information that was provided on the nature of the failures (i.e., opens or shorts) included high resistance shorts that were occurring in those specified areas. The surface finish was a eutectic HASL (hot air solder leveling) and the solder paste used was a water soluble Sn/Pb(tin/lead).
Technical Library | 2020-05-08 18:22:31.0
A customer contacted the Helpline to perform analysis on a lead-free assembly which exhibited intermittent functionality. The lead-free assembly exhibiting intermittent functionality when pressure was applied to the ball grid array (BGA) packages. Industrial adaptation of a Restriction of Hazardous Substances (RoHS) compliant solder standard has created a new host of failure modes observed in lead-free assemblies. Pad cratering occurs when fractures propagate along the epoxy resin layer on the underside of the BGA connecting pads. While originating from process, design, and end use conditions, it is the combination of a rigid lead-free solder with inflexible printed circuit board (PCB) laminates that has advanced the prevalence of this condition. Pad cratering is simply the result of mechanical stress exceeding material limitations.
Technical Library | 2012-12-17 22:05:22.0
Package on Package (PoP) has become a relatively common component being used in mobile electronics as it allows for saving space in the board layout due to the 3D package layout. To insure device reliability through drop tests and thermal cycling as well as for protecting proprietary programming of the device either one or both interconnect layers are typically underfilled. When underfill is applied to a PoP, or any component for that matter, there is a requirement that the board layout is such that there is room for an underfill reservoir so that the underfill material does not come in contact with surrounding components. The preferred method to dispensing the underfill material is through a jetting process that minimizes the wet out area of the fluid reservoir compared to traditional needle dispensing. To further minimize the wet out area multiple passes are used so that the material required to underfill the component is not dispensed at once requiring a greater wet out area. Dispensing the underfill material in multiple passes is an effective way to reduce the wet out area and decrease the distance that surrounding components can be placed, however, this comes with a process compromise of additional processing time in the underfill dispenser. The purpose of this paper is to provide insight to the inverse relationship that exists between the wet out area of the underfill reservoir and the production time for the underfill process.
Technical Library | 2023-11-09 08:53:45.0
Crafting an Efficient SMT Conformal Coating Line for Double-Sided PCBA In the intricate realm of electronics manufacturing, selecting the ideal SMT conformal coating line can seem like a challenging quest. The pursuit of a solution that seamlessly integrates efficiency, reliability, and performance is the ultimate goal. In this article, we embark on a journey to unravel the secrets of a standard SMT conformal coating line, using a captivating visual guide as our compass. The Symphony Of Components In An SMT Conformal Coating Line Picture a finely orchestrated symphony, with each instrument playing a unique role in this PCB coating process. The star performers in this lineup include: Transfer Conveyor: These act as the stage where the PCB's journey begins. Think of them as the entry and exit points for your precious boards, allowing a smooth, choreographed dance through the line. 1st Coating Machine: As the first movement in this musical journey, this machine, partnered with the initial curing station, lays down the foundation – applying adhesive to one side of the PCB. Inspection Conveyor: After the initial curing, our inspectors take center stage, using these transfer stations to carefully evaluate the coating's quality. 1st Curing Oven: This is where the magic happens. The first curing oven solidifies the adhesive applied in the previous act, setting the tone for a flawless performance. Flipper Machine: The flipper machine takes the spotlight, gracefully turning the PCB to reveal its other side, ensuring both faces receive their share of adhesion. 2nd Coating Machine: With a newfound perspective, the second coating machine takes the stage, applying adhesive to the reverse side of the PCB. 2nd Curing Oven: The grand finale! The second curing oven brings our symphony to a breathtaking close, solidifying the adhesive applied in the second act, creating a harmonious, dual-sided masterpiece. Efficiency Meets Dual-Side Coating This SMT conformal coating line is like a well-choreographed ballet that requires at least two dancers. One stands at the front, carefully loading PCBs onto the stage, guiding them through the first act. After the flip, the second dancer carries them through the second act, with both sides perfectly coated, ensuring a flawless performance for applications requiring dual-sided adhesion. UV Curing Oven For Illuminating Results For applications that embrace UV-curable adhesives, our line includes UV curing ovens, adding a layer of brilliance to the process and ensuring an efficient solidification of adhesives. Transfer Stations With A Touch Of Magic Within this symphony, the transfer stations wear a touch of magic – the second and fourth stations feature enchanting blue glass covers illuminated by embedded LED lights. These stations offer operators a clear view of the adhesive quality, allowing for meticulous inspections. The blue glass covers also act as protective shields, guarding freshly coated PCBs from the ever-present dust fairies. Certified Excellence: European Standards And CE Certification Ensuring that our performance meets the highest standards, our entire ensemble adheres to stringent European safety standards and proudly boasts CE certification, a testament to compliance with safety, health, and environmental protection requirements. A Variety Of Coating Machines For Your Unique Needs Our lineup doesn't just feature one star, but an ensemble of coating machines, including models like I.C.T-T550, I.C.T-T550U, I.C.T-T600, and I.C.T-T650. For an encore performance with detailed specifications of each model, please refer to our dedicated article. Additionally, for a captivating exploration of the right coating valve for your adhesive, please visit our comprehensive guide. Single-Sided PCB Coating For those who prefer a single board, our dedicated article on single-sided PCB coating is a spotlight on this specialized process. In the dynamic world of electronics manufacturing, our SMT conformal coating line stands as a versatile and reliable performance. With dual-sided coating capabilities, adherence to European safety standards, and CE certification, we offer a comprehensive platform for your coating needs. Join us in this symphony and explore our range of coating machines and accessories to enhance your conformal coating process. It's a performance that promises to leave you in awe!
Technical Library | 2013-09-19 17:25:32.0
The next generation of smart phones will demand very thin multi-layer boards to reduce the product thickness again. This paper shows three different manufacturing approaches, which can be used for very thin any-layer build-ups. The technological approaches are compared on reliability level – the any-layer copper filled micro-via technology which is to be considered as state of the art technology for high end phones and the ALIVH-C/G technology that is well established in Japan. A test vehicle design featuring test coupons for comprehensive reliability test series has been defined as target application for investigation...
Technical Library | 2012-12-26 20:18:50.0
①Single side The basic flexible printed circuit board is used of substrate of single side pcb materials and coated coverlay after finishing printed. ②Double sided That is made of substrates of double sided printed circuit board with double surface coated coverlays after finishing printed. ③Single copper foil with double coverlays Single copper foil coated different coverlays with double surface after finishing printed. ④Air gap Laminating two single printed circuit board together with no glue and bare design to meet high flexibility requirements. ⑤Multilayer That is designed for three and above circuit layers by laminating single side printed circuit board or double sided printed circuit board. ⑥COF IC chips and electronic components are installed on the flexible circuit board directly. ⑦Rigid-Flexible PCB Combined to rigid PCB with supporting and flexible PCB with high flexibility.
Technical Library | 2009-05-21 13:41:05.0
Failure due to board flex cracks persists as the dominant failure mode in multi-layer ceramic capacitors (MLCC). (...) This paper is intended to show the impact of temperature cycling, high-temperature life tests, and multiple bend exposures to the MLCC with this flexible termination.
Technical Library | 2024-05-16 16:06:24.0
Much like actual cities where streets and roads connect buildings together, ICs on a board are connected to each other with copper traces. And just like any metropolitan city, urban expansion tends to move vertically instead of horizontally, but instead of multi-story buildings, we get multilayer boards. Vias are copper-plated holes spanning through the different layers of a given board or panel. They are the entrance locations to the subway stations, if you will. Having those multilayer boards has enabled electronic design to minimize the size of boards immensely without compromising on the complexity.
Technical Library | 1999-07-20 09:15:30.0
What affects the price of boards? Number of layers: Limit the number of layers as much as possible. If higher quantities are anticipated, spend the extra time and money in engineering to minimize layer count....
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