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 | 2023-07-22 02:26:05.0
Patch offset; Uneven patches throughout the substrate (each substrate is offset in a different way); Only part of the substrate is offset; Only certain components are offset; The patch Angle is offset; Component absorption error; Laser identification (component identification) error; Nozzle loading and unloading error; Mark (BOC mark, IC mark) identification error; Image recognition error (KE-2060 only); Analysis of the main reasons for throwing material. More information about KINGSUN please Contact US at jenny@ksunsmt.com or visit www.ksunsmt.com
Technical Library | 2023-09-16 07:16:54.0
JUKI is a leading manufacturer of SMT pick and place machines, and their products are known for their high quality, precision, and reliability. In this article, we will discuss the benefits of using JUKI PCB SMT pick and place machines, including: High accuracy and precision Fast production speeds Flexible capabilities Reliable performance
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 | 2007-05-31 19:05:55.0
This paper discusses solder paste printing and flux dipping assembly processes for 0.4 and 0.5mm pitch lead-free WLCSPs and the corresponding assembly results and thermal cyclic reliability obtained. Variables evaluated include reflow ambient, paste type, and stencil design. Reliability is also compared to results for the same components assembled under identical conditions using SnPb solder.
Technical Library | 2019-05-22 21:24:05.0
voidless treatment Smaller components -> miniaturization (01005 capability) Large board handling -> dynamic preheating for large board repair Repeatable processes -> flux and paste application (Dip and Print), residual solder removal (scavenging), dispensing, multiple component handling, and traceability Operator support -> higher automation, software guidance
Technical Library | 2016-05-30 22:54:52.0
New engineered cleaning and defluxing agents promise great improvement in cleaning and reliability for electronic assemblies. As complexity grows and dimensions shrink in high reliability electronics, the need for materials compatibility and effectiveness in cleaning and rinsing is vital.
Technical Library | 1999-05-07 10:16:31.0
This paper will describe practical aspects of a redundancy implementation on a high-volume cache memory product. Topics covered include various aspects of redundancy from a design and product engineering perspective; and present test development methods for future product implementations.
Technical Library | 2010-04-29 21:40:37.0
The purpose of this paper is to investigate the effects of reflow time, reflow peak temperature, thermal shock and thermal aging on the intermetallic compound (IMC) thickness for Sn3.0Ag0.5Cu (SAC305) soldered joints.
Technical Library | 2009-11-18 23:37:52.0
Accurate component placement is a basic requirement for any pick and place machine. The first step towards accurate placement is accurate centering, or measurement of the component’s position on the placement head. One of the most widely used centering methods for ICs, connectors, and odd‐shaped components are a camera based system that measures the component position relative to a known point. Camera based centering systems include three main elements: lighting, camera, and software. Each of these elements are critical to obtaining an accurate measurement of the component and ultimately for accurate component placement on the PCB. As the old adage goes, the system is only as strong as its weakest link.
