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 | 2019-06-11 09:34:37.0
Recently ACI Technologies was asked to perform failure analysis on a hermetically sealed transistor for potential electrostatic discharge (ESD) or electrostatic overstress (EOS). ACI was asked to determine if the field-failed transistor was damaged by ESD or EOS. In order to properly assess the failure, additional samples were requested.
Technical Library | 2021-02-20 00:55:47.0
Customers must be able to rely on accurate humidity indication as an assurance of SMD quality and fitness for processing and use. Without it, they might accept SMDs from suppliers that have already been irreparably damaged by moisture during storage or transit. Or, they might approve for processing SMDs that have been improperly or insufficiently heat-dried. Beyond the processing questions, there are financial questions: Where did the dry pack problems originate and who--supplier, customer, shipper--is financially responsible for the damaged SMDs? In response, Clariant, the originator of the color change humidity indicator card, and a member of the JEDEC's Subcommittee 14.1, "Reliability and Test Methods for Packaged Devices," created a new "non-reversible" halogen and cobalt dichloride free humidity indicator card. This HIC combines two reversible indicators (5% and 10%) with a new non-reversible (60% RH) indicator spot. (Figure 1) The 5% and 10% reversible spots work the way similar indicators do: they change color from blue (dry), to lavender, to pink (wet) to indicate humidity exposure at the indicated levels. If humidity levels drop, they will gradually revert back to blue.
Technical Library | 2019-05-24 09:27:33.0
Decapsulation, or de-cap, is a failure analysis technique which involves the removal of material packaging from an integrated circuit (IC). After de-cap, visual inspection by optical microscopy of the internal circuitry may reveal areas where damage is most likely to have occurred. In addition, scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) can identify the composition of any anomalies present after de-cap under higher magnification. The removal process of package material can be done either mechanically or chemically depending on the design of the integrated circuit. With ceramic packaging, de-cap is usually done mechanically by chiseling off the top with a fine razor and small hammer. For plastic packaging, de-cap requires chemical etching by strong acids. In this Tech Tips article, de-cap by chemical etching will be outlined step by step.
Technical Library | 2019-05-29 10:38:59.0
Decapsulation, or de-cap, is a failure analysis technique which involves the removal of material packaging from an integrated circuit (IC). After de-cap, visual inspection by optical microscopy of the internal circuitry may reveal areas where damage is most likely to have occurred. In addition, scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) can identify the composition of any anomalies present after de-cap under higher magnification. The removal process of package material can be done either mechanically or chemically depending on the design of the integrated circuit. With ceramic packaging, de-cap is usually done mechanically by chiseling off the top with a fine razor and small hammer. For plastic packaging, de-cap requires chemical etching by strong acids. In this Tech Tips article, de-cap by chemical etching will be outlined step by step.
Technical Library | 2019-09-23 09:35:00.0
Failure analysis (FA), by its very nature, is needed only when things goawry. Before any testing is performed on the sample, a decision mustbe made as to whether or not the sample is allowed to be destroyedin the process of testing. Non-destructive testing can allow for re-use of the assembly since the functionality is not altered, but there still remains the possibility that inadvertent damage can occur through the course of the analysis. If non-destructive testing is preferred, then the following types of analysis can be performed. The testing can be divided into four categories: visual, X-ray (X-ray imaging and X-ray fluorescence), cleanliness (resistivity of solvent extract, ion chromatography, and Fourier transform infrared spectroscopy), and mechanical (non-destructive wire bond pull).
Technical Library | 2021-09-02 08:17:07.0
We are a professional manufacturer of PCB depaneling machines, which is workable for all boards, including flex and regid boards, v-scored boards and routed boards. Laser pcb depaneling is non-contact way without mechanical stress,this solution is good for modern precision PCB depaneling. It has below advantages: 1. No dust The production environment of the circuit board industry is carried out in the dust-free workshop. The traditional pcb depaneling equipment, such as blade moving type machine, will inevitably produce residues and micro powder, which will pollute the 10000 and 1000 class dust-free workshops and affect the conductivity of products. The UV laser PCB cutting machine is a vaporization processing process, which will not produce dust and is conducive to the conductivity of the product. 2. High cutting precision The processing gap of high-precision traditional processing equipment can not reach the gap width of less than 100 microns, which will cause certain damage to the lines on the edge or PCBA circuit board containing components. The focus spot of the laser cutting machine is small, and the ultraviolet cold processing mode has little thermal impact on the edge of the circuit board. The cutting position accuracy is less than 50 microns, and the cutting size accuracy is less than 30 microns, which will not affect the edge of the circuit board, and the precision is high. 3. No stress Traditional processing methods generally have V-grooves, which will cause certain damage to the board in the manufacturing process. The UV laser PCB cutting machine can directly cut the bare board without making V-grooves. In addition, the traditional processing methods directly use tools to act on the circuit board, especially the stamping method has a great impact on the circuit board, which is easy to cause board deformation. The laser cutting machine is a non-contact processing mode, which acts on the surface of the material through the high-energy beam, which will not cause the influence of stress and the deformation and damage of the circuit board. 4. For special-shaped cutting, it is easy to automate The UV laser PCB cutting machine can cut for any shape without replacing any props and fixtures, and without steel mesh. The same equipment can meet special-shaped and straight-line cutting, which is easy to realize assembly line automatic production and high flexibility. It is easy to improve production efficiency and save production process and production cycle. In particular, it can quickly and efficiently meet the needs of rapid proofing, directly import the drawing, and then locate the cutting. 5. High compatibility The UV laser PCB cutting machine can process the materials around the circuit board, such as PCB, FPC, covering film, pet, reinforcing board, IC, ultra-thin metal cutting, etc. it has strong practicability, is compatible with the processing of a variety of materials, is easy to operate, can be imported into the drawing, does not need to adjust any mechanical parts, and is easy to operate and maintain. 6. Good cutting edge effect The cutting edge is smooth and neat without burr. It can be processed and formed directly according to the size of the drawing, which is conducive to improving the yield of the product. It can be directly installed into the subsequent process without further processing. For more details about UV laser depaneling, please feel free to contact us. www.pcbdepanelingrouter.com
Technical Library | 2007-02-01 10:08:40.0
The increased replacement of high lead count SMT devices with BGAs and other high ball count area array packages has brought increased challenges to PCB rework and repair. Often solder mask areas surrounding BGA pad areas are damaged when components are removed.
Technical Library | 2015-08-27 15:32:16.0
Ever since there has been a widespread usage of surface mount parts, the trend of continued shrinkage of devices with ever finer pitches has continued to challenge PCB assemblers for the rework of same. Todays' pitches are commonly 0.5 to 0.4mm with packages of tiny outline sizes, 5 -10mm square, making the rework of such devices a challenge. In addition to the handling and inspection challenges comes the board density. Spacing to neighboring components continues to be compressed so the rework techniques should not damage neighboring components.
Technical Library | 2021-07-27 14:57:18.0
It should be noted that this is an overview paper that represents the early stages of an ongoing investigation into the causes and effects between conductive anodic filament (CAF) formation and printed wiring board (PWB) material damage. Our belief is that certain or specific types of material damage can increase the propensity for CAF formation. The preliminary data collected suggests is that there is no statistical correlation between the general definition of material damage (cohesive failure) and CAF. The resulting dichotomy is that we find no CAF failures in some coupons that have obvious material damage and we find CAF failures in coupons that don't exhibit material damage.
