Thermal Management of QFN 48 Package Attached to Different Multi-Layers of Printed Circuit Board Designs

2003 ◽  
Author(s):  
John Chia ◽  
Charles Yang
Keyword(s):  
Thermal Efficiency ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Thermal Dissipation ◽  
Substrate Type ◽  
Printed Circuit ◽  
Higher Power ◽  
Body Sizes ◽  
Reliability Issue ◽  
Ic Package

A near CSP plastic encapsulated package with a quad flat non-leaded (QFN) structure has been drawn much attention due to it small size and lightweight applications. Thermal efficiency is the major concern for adopting such type of package in place of TSSOP package. The thermal dissipation for electronics with the higher power consumption is current developing to it uppermost limitation as a wire bonded, lead-frame substrate type of QFN with various pine counts and body sizes. It is therefore an object of the present study to investigate thermal performance of QFN package optimum design attached on different layers and thickness of laminated printed circuit board (PCB), which is further related to reliability issue of this type of IC package. Numerical simulation illustrates how the thermal efficiency of the QFN package can be reached with different PCB designs and airflow conditions.

Print Copper on Ceramic for High Reliability Electronics

2015 ◽  
Vol 2015 (1) ◽  
pp. 000330-000335
Author(s):  
Ryan Persons ◽  
Paul Gundel
Keyword(s):  
Screen Printing ◽  
Printed Circuit Board ◽  
High Reliability ◽  
Dielectric Materials ◽  
Circuit Board ◽  
Printed Circuit ◽  
Design Flexibility ◽  
Higher Power ◽  
Power Densities ◽  
Primary Substrate

In the power electronics world, Direct Bonded Copper (DBC) is the primary substrate technology. In this paper, we will discuss an alternative technology utilizing screen printable copper pastes (Thick Printed Copper - TPC) on a variety of substrate technologies including Alumina (Al2O3) and Aluminum Nitride (AlN). These materials when processed, look and perform similar to DBC, but exhibit superior reliability and excellent design flexibility. DBC has drawbacks when it comes to thermal mechanical reliability and lacks the flexibility to have multiple copper thicknesses for power and signal circuits within the same design, which is easily achieved via screen printing. The benefits of this TPC system will be demonstrated through data generated on passive thermal shock tests in comparison to high end DBC. Furthermore, this Thick Print Copper technology has the excellent potential for replacing high end Metal Core Printed Circuit Board (MCPCB) technology due to utilization of higher thermal conductive dielectric materials like Al2O3 and AlN. This will allow for designers to drive their LED's harder and effectively producing LED modules with higher power densities.

Improvement of Printed Circuit Board Assembly Process in 2.4GHz RF Circuit Products

2008 ◽  
Author(s):  
Mu-Chun Wang ◽  
Zhen-Ying Hsieh ◽  
Ting-Yu Yang ◽  
Chia-Hao Tu ◽  
Shuang-Yuan Chen
Keyword(s):  
Printed Circuit Board ◽  
Good Method ◽  
Circuit Board ◽  
Thermal Dissipation ◽  
Electronic Components ◽  
Printed Circuit Board Assembly ◽  
Process Technology ◽  
Printed Circuit ◽  
Pcb Assembly ◽  
Functional Product

The semiconductor process technology and the circuit design concept are continuously improved at the recent era. The product cost is gradually decreased, too. The commercial electronic products generally cover ICs, external components and printed circuit board (PCB). After the circuit layout blueprints are completed, engineers will transfer them into PCB as a prototype. The next step is to integrate some contributed electronic components to form a functional product. This second step is called as PCB assembly (PCBA). However, the bigger copper area on PCB will provide a good thermal dissipation. This effect will degrade the solderability and increase the contact resistance while the electronic components are integrated on PCB. The product performance, therefore, is deteriorated. Contriving some special empty boundary shapes neighboring the connected pins of integrated electronic components to soften the thermal dissipation ability of copper layer on printed circuit substrate is a good method. We design some useful patterns to conquer this issue and increase the PCB assembly yield from 70% to 95%. The other efforts are to study the flow rate of isolated ink in PCBA production line and suitably control the solder temperature. Because some electronic components are composed by plastic materials, higher temperature will damage the external shapes of them and the PCB has the bending possibility. These two beneficial efforts also contribute the assembly yield well in 2.4GHz radio-frequency (RF) products.

Characteristics of Radiated Emission from a Printed Circuit Board with a Slit

2012 ◽  
Vol 132 (6) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Nakayama ◽  
Kenichi Kagoshima ◽  
Shigeki Takeda
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Radiated Emission

Confirming the Signal Integrity in Transmission of Digital Signals on Microstrip Straight Circuits via the Eye Diagrams

2014 ◽  
Vol 5 (1) ◽  
pp. 737-741
Author(s):  
Alejandro Dueñas Jiménez ◽  
Francisco Jiménez Hernández
Keyword(s):  
Integrated Circuits ◽  
Printed Circuit Board ◽  
Signal Integrity ◽  
High Volume ◽  
Information Storage ◽  
Circuit Board ◽  
Electromagnetic Simulation ◽  
Electronic Systems ◽  
Digital Signals ◽  
Printed Circuit

Because of the high volume of processing, transmission, and information storage, electronic systems presently requires faster clock speeds tosynchronizethe integrated circuits. Presently the “speeds” on the connections of a printed circuit board (PCB) are in the order of the GHz. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift- effects caused by phenomena like cross talk, ringing and over shot are present and may be undesirable for the performance of a circuit or system.Some of these phrases were extracted from the chapter eight of book “2-D Electromagnetic Simulation of Passive Microstrip Circuits” from the corresponding author of this paper.

Root Cause Analysis of a Connector Time-Delayed Fracture

2015 ◽  
Author(s):  
Prabjit Singh ◽  
Ying Yu ◽  
Robert E. Davis
Keyword(s):  
Printed Circuit Board ◽  
Ceramic Substrate ◽  
Circuit Board ◽  
Delayed Fracture ◽  
Ceramic Substrates ◽  
Printed Circuit ◽  
Root Cause ◽  
Chip Carrier ◽  
Electrical Connections ◽  
Grain Boundary Grooves

Abstract A land-grid array connector, electrically connecting an array of plated contact pads on a ceramic substrate chip carrier to plated contact pads on a printed circuit board (PCB), failed in a year after assembly due to time-delayed fracture of multiple C-shaped spring connectors. The land-grid-array connectors analyzed had arrays of connectors consisting of gold on nickel plated Be-Cu C-shaped springs in compression that made electrical connections between the pads on the ceramic substrates and the PCBs. Metallography, fractography and surface analyses revealed the root cause of the C-spring connector fracture to be plating solutions trapped in deep grain boundary grooves etched into the C-spring connectors during the pre-plating cleaning operation. The stress necessary for the stress corrosion cracking mechanism was provided by the C-spring connectors, in the land-grid array, being compressed between the ceramic substrate and the printed circuit board.

Application of Lock-in Thermography on PCB for Fault Localization and Validation of Failure Mechanism Due to External Discrete Component Variation

2010 ◽  
Author(s):  
William Ng ◽  
Kevin Weaver ◽  
Zachary Gemmill ◽  
Herve Deslandes ◽  
Rudolf Schlangen
Keyword(s):  
Failure Mechanism ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Hot Spot ◽  
Circuit Board ◽  
Discrete Component ◽  
Printed Circuit ◽  
Thermal Signature ◽  
Lock In

Abstract This paper demonstrates the use of a real time lock-in thermography (LIT) system to non-destructively characterize thermal events prior to the failing of an integrated circuit (IC) device. A case study using a packaged IC mounted on printed circuit board (PCB) is presented. The result validated the failing model by observing the thermal signature on the package. Subsequent analysis from the backside of the IC identified a hot spot in internal circuitry sensitive to varying value of external discrete component (inductor) on PCB.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

Materials Characterization of Lead Free Compositions for Minimum Temperature SMT Processes at the SLI-Second Level Interconnect Solder Joint

2004 ◽  
Author(s):  
Norman J. Armendariz ◽  
Prawin Paulraj
Keyword(s):  
Solder Joint ◽  
Printed Circuit Board ◽  
Gold Surface ◽  
Circuit Board ◽  
Lead Free ◽  
Processing Temperature ◽  
The European Union ◽  
Printed Circuit ◽  
Higher Temperature ◽  
Tin Silver Copper

Abstract The European Union is banning the use of Pb in electronic products starting July 1st, 2006. Printed circuit board assemblies or “motherboards” require that planned CPU sockets and BGA chipsets use lead-free solder ball compositions at the second level interconnections (SLI) to attach to a printed circuit board (PCB) and survive various assembly and reliability test conditions for end-use deployment. Intel is pro-actively preparing for this anticipated Pb ban, by evaluating a new lead free (LF) solder alloy in the ternary Tin- Silver-Copper (Sn4.0Ag0.5Cu) system and developing higher temperature board assembly processes. This will be pursued with a focus on achieving the lowest process temperature required to avoid deleterious higher temperature effects and still achieve a metallurgically compatible solder joint. One primary factor is the elevated peak reflow temperature required for surface mount technology (SMT) LF assembly, which is approximately 250 °C compared to present eutectic tin/lead (Sn37Pb) reflow temperatures of around 220 °C. In addition, extended SMT time-above-liquidus (TAL) and subsequent cooling rates are also a concern not only for the critical BGA chipsets and CPU BGA sockets but to other components similarly attached to the same PCB substrate. PCBs used were conventional FR-4 substrates with organic solder preservative on the copper pads and mechanical daisychanged FCBGA components with direct immersion gold surface finish on their copper pads. However, a materials analysis method and approach is also required to characterize and evaluate the effect of low peak temperature LF SMT processing on the PBA SLI to identify the absolute limits or “cliffs” and determine if the minimum processing temperature and TAL could be further lowered. The SLI system is characterized using various microanalytical techniques, such as, conventional optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and microhardness testing. In addition, the SLI is further characterized using macroanalytical techniques such as dye penetrant testing (DPT) with controlled tensile testing for mechanical strength in addition to disbond and crack area mapping to complete the analysis.

Magnetic Emission Mapping for Passive Integrated Components Characterisation

2003 ◽  
Author(s):  
O. Crépel ◽  
Y. Bouttement ◽  
P. Descamps ◽  
C. Goupil ◽  
P. Perdu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mobile Phone ◽  
Printed Circuit Board ◽  
Magnetic Sensors ◽  
Circuit Board ◽  
Magnetic Disturbance ◽  
Passive Components ◽  
Printed Circuit ◽  
Integrated Inductor ◽  
The Magnetic Field

Abstract We developed a system and a method to characterize the magnetic field induced by circuit board and electronic component, especially integrated inductor, with magnetic sensors. The different magnetic sensors are presented and several applications using this method are discussed. Particularly, in several semiconductor applications (e.g. Mobile phone), active dies are integrated with passive components. To minimize magnetic disturbance, arbitrary margin distances are used. We present a system to characterize precisely the magnetic emission to insure that the margin is sufficient and to reduce the size of the printed circuit board.

Sign in / Sign up

Export Citation Format

Share Document