Oxidation characteristics of commercial copper-based lead frame surface and the bonding with epoxy molding compounds

2019 ◽  
Vol 99 ◽  
pp. 161-167 ◽  
Author(s):  
Shih-Chieh Chao ◽  
Wei-Chen Huang ◽  
Jen-Hsiang Liu ◽  
Jenn-Ming Song ◽  
Po-Yen Shen ◽  
...  
Keyword(s):  
Lead Frame ◽  
Molding Compounds ◽  
Oxidation Characteristics ◽  
Commercial Copper

Adhesion between Ni/Fe lead frame and epoxy molding compounds in IC packages

1996 ◽  
Vol 10 (1) ◽  
pp. 1-15 ◽  
Author(s):  
SHIN'ICHIRO Asai ◽  
Takayuki Ando ◽  
Masayuki Tobita
Keyword(s):  
Lead Frame ◽  
Molding Compounds

Measurement of Hygroscopic Swelling in Mold Compounds and Its Effect on PEM Reliability

2003 ◽  
Author(s):  
Eric Stellrecht ◽  
Bongtae Han ◽  
Michael Pecht
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Experimental Method ◽  
Lead Frame ◽  
Thermally Induced ◽  
Molding Compounds ◽  
Hygroscopic Swelling ◽  
Swelling Coefficient ◽  
Package Reliability

Hygroscopic stresses arise in a plastic encapsulated microcircuit (PEM) when the mold compound swells upon absorbing moisture and the lead frame, die paddle, and silicon die, do not experience swelling. Similar to the thermal stress produced by the mismatch of coefficients of thermal expansion between adjacent materials, the hygroscopic stress increases as the hygroscopic swelling coefficient of the mold compound increases. Accurate measurement of hygroscopic swelling is essential in assessing the effect of hygroscopic stresses on package reliability. In this paper, a whole-field experimental method to characterize the hygroscopic swelling of mold compounds is proposed. The method is implemented to determine the hygroscopic swelling and the corresponding coefficient of hygroscopic contraction of five commercial molding compounds. A comparison between the hygroscopic and thermally induced mismatch strains in PEMs is presented and its implication on PEMs reliability is discussed.

Evaluation of the Moisture Sensitivity of Molding Compounds of IC’s Packages

2000 ◽  
Vol 123 (1) ◽  
pp. 16-18 ◽  
Author(s):  
H. Fre´mont ◽  
J. Y. Dele´tage ◽  
A. Pintus ◽  
Y. Danto
Keyword(s):  
Finite Element ◽  
Diffusion Coefficient ◽  
Diffusion Process ◽  
Moisture Diffusion ◽  
Fickian Diffusion ◽  
Lead Frame ◽  
Significant Cost ◽  
Moisture Sensitivity ◽  
Molding Compounds ◽  
Cost Reductions

Plastic encapsulated devices are of great interest against their ceramic or metallic counterparts, as they permit significant cost reductions. However, they are more sensitive to moisture ingress, which can lead to reliability problems. Moisture can penetrate either through the polymer or along the interface between the leads and the encapsulant. Samples of 3 different polymers usually used for IC’s encapsulation, either pure or containing a lead frame with the lead terminations, were aged under different RH conditions. Results show that the penetration through the polymer is preponderant face to the progression along the leads. In a first approach, this penetration can be considered as a diffusion process, following the Fick’s law; the diffusion coefficient D and the saturation coefficient S can be deduced from the measurements as a function of the relative humidity. These values can be used in finite element simulations, in order to evaluate the moisture ingress as a function of time within an IC of a given geometry. Moisture diffusion within these new resins is a very long process. In fact, a first “saturation” occurs after a few hours of aging, but if samples are left longer in the oven, a new diffusion process occurs, not leading to a real saturation. Hence processes different than pure fickian diffusion occur in the polymers.

Backside Mechanical Preparation Methodology for Effective Failure Analysis on Small and Non-Exposed Die Paddle Package

2018 ◽  
Author(s):  
Ong Pei Hoon ◽  
Ng Kiong Kay ◽  
Gwee Hoon Yen
Keyword(s):  
Failure Analysis ◽  
Chemical Etching ◽  
Chemical Resistance ◽  
Etching Time ◽  
Lead Frame ◽  
Front Side ◽  
Electrical Measurements ◽  
Mechanical Preparation ◽  
Die Surface ◽  
Copper Lead

Abstract Chemical etching is commonly used in exposing the die surface from die front-side and die backside because of its quick etching time, burr-free and stress-free. However, this technique is risky when performing copper lead frame etching during backside preparation on small and non-exposed die paddle package. The drawback of this technique is that the copper leads will be over etched by 65% Acid Nitric Fuming even though the device’s leads are protected by chemical resistance tape. Consequently, the device is not able to proceed to any other further electrical measurements. Therefore, we introduced mechanical preparation as an alternative solution to replace the existing procedure. With the new method, we are able to ensure the copper leads are intact for the electrical measurements to improve the effectiveness and accuracy of physical failure analysis.

Preventing whiskers in electrodeposited tin for semiconductor lead frame applications

Circuit World ◽  
2004 ◽  
Vol 30 (2) ◽  
pp. 20-24 ◽  
Author(s):  
Keith Whitlaw ◽  
André Egli ◽  
Mike Toben
Keyword(s):  
Lead Frame
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