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 | 2019-06-12 10:33:58.0
The success of ball grid array (BGA) placement on electronic assemblies is as much a matter of proper preparation and planning, as it is technique. In some designs, it is more appropriate to apply BGAs using a rework station that isolates the placement of the device, without subjecting the entire assembly to thermal reflow. This is especially beneficial in board constructions where the number of BGAs is limited, and the application of the solder paste is difficult, due to small pitch features that stretch the limitation of the stencil construction. Another application for rework stations, involves very large and thermally conductive BGAs, which will not uniformly reflow with other components on the assembly, and may require special process parameters for their proper placement. The most common use of BGA rework stations are for assemblies requiring BGA removal and replacements due to failures in the initial assembly stage.
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 | 2020-03-09 10:50:17.0
A customer called the Helpline seeking advice for cleaning no-clean fluxes prior to applying a conformal coating. The customer's assemblies were manufactured with a no-clean rosin based solder paste (ROL0) and were cleaned with an isopropyl alcohol (IPA) wash. After cleaning, a white residue was sometimes found in areas with high paste concentrations and was interfering with the adhesion of the conformal coating (Figure 1). For conformal coatings to adhere properly, the printed circuit board (PCB) surface must be clean of fluxes and other residues. In addition, ionic contamination left by flux residues can lead to corrosion and dendrite growth, two common causes of electronic opens and shorts. Other residues can lead to unwanted impedance and physical interference with moving parts.
Technical Library | 2020-04-01 14:24:56.0
It happens much too often; manufacturing engineers are brought into a NEW product design phase at the very end of a design and are asked to provide input that should have been provided much earlier. One needs to understand how the circuit board design and quality of the manufacturing process not only effects assembly yield and product reliability, but how it could also affect the results of any testing that is done to circuit packs during prototyping. It is important that any circuit pack (including prototypes) that will be used in reliability, performance and functional testing be designed with the proper features and assembled with a manufacturing process that has been developed to produce a high-quality assembly. If not, the results of any testing might not represent the actual characteristics of the design and provide miss-guidance to future changes.
Technical Library | 2020-04-14 15:49:38.0
The number of through-hole components on printed circuit boards (PCB) has declined significantly over the last decade. Miniaturization in electronics has resulted in less THT (through-hole technology) and leads with a finer pitch. For this reason, the soldering of these components has also changed from wave soldering to Point-to-point selective soldering. Soldering these small, fine-pitch components is a challenge when surface mount components (SMD) are positioned very close to THT components on the PCB layout. This study, done in cooperation with a large automotive EMS customer, defines the process windows for through-hole technology for fine-pitch components. It determines what is feasible to solder and defines layout design parameter that make soldering possible with SMD areas and other components on the assembly.
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 | 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 | 2023-11-07 09:36:38.0
How to Choose the Right PCB Coating Machine Line Selecting the ideal equipment for your PCB coating line can be a complex task. In this article, we will guide you through the critical components of a standard PCB coating machine line and their solutions to common challenges. We'll delve into the line's composition, including the elevator, transfer station, coating machine, inspection station, curing oven, and their interconnectedness through a return conveyor. Let's explore each element and understand its role. Components of a PCB Coating Machine Line: Elevator: The PCB coating process starts with an elevator, efficiently transporting PCB boards to the next stage. Transfer Station: After the elevator, boards are conveyed to a transfer station, preparing them for the coating process. Coating Machine: The heart of the PCB coating line is the coating machine. We offer a range of coating machines, including I.C.T-T550, I.C.T-T550U, I.C.T-T600, and I.C.T-T650. Inspection Conveyor: Following the coating process, the boards move to an inspection station. The second transfer station is equipped with LED lights and a blue glass cover, enabling operators to closely inspect the coating quality. This feature is vital for ensuring consistent, dust-free coatings. Curing Oven: For UV-curable adhesives, we provide a UV curing oven to effectively solidify the adhesive. Return Conveyor: Beneath the entire line runs a return conveyor, connected to the elevator. This conveyor system efficiently returns PCBs from the last elevator to the first one, reducing manual handling and streamlining operations. The Advantages of the PCB Coating Line Design: 1. Easy Accessibility: The operator's station is strategically located beside the coating machine, ensuring easy access for setup and adjustments. 2. Enhanced Efficiency: The integrated return conveyor eliminates the need for manual transport, optimizing workflow. 3. Quality Control: The inspection station with the blue glass cover enables operators to inspect coatings for quality and cleanliness. 4. Dust Prevention: The blue glass cover also serves as a barrier to prevent dust contamination on freshly coated PCBs. Selecting the right PCB coating machine line is essential for achieving quality and efficiency in your operations. Our meticulously designed equipment line, along with its well-engineered components, can help you attain superior results. If you have further questions or need assistance in choosing the best solution for your specific requirements, please do not hesitate to contact us. We are committed to providing solutions that meet your needs and exceed your expectations.
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!
