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This paper proposes a new method to determine the baking time for moisture-sensitive packages prior to dry pack. The concept is based on consideration of the continuous drying process for a package within moisture barrier bags (MBB), which contain a desiccant. If the moisture is not completely dried out during bake (usually at 125°C), the residual moisture will continue to diffuse out of the package body during storage and shipment in the MBB. In this paper, a 2.5D package is used for a worst-case scenario simulation through finite element modeling. It shows that after a 24hr bake at 125°C, the residual moisture weight gain remains 13% of the total saturated weight gain, and the maximum moisture concentration remains as high as 40% of the saturated moisture concentration; however, after 4 weeks of storage at 30°C in the MBB the residual moisture weight decreases to less than 1%, and the maximum saturated moisture concentration decreases to less than 5% of the saturated moisture concentration. Depending upon package construction, storage conditions and storage time before customer opening of MBB, the modeling results show that consideration of moisture diffusion in the MBB may permit the bake schedule to be shortened.

Semi fabricates based on Cu(In,Ga)Se 2 solar cells with flexible metallic substrate packaged in innovative moisture barriers that demonstrated failure after damp heat exposure were analyzed using thermographic imaging, luminescence imaging and optical microscopy. This made it possible to visualize and identify the failure modes and find explanations for the causes of failure. The most important causes of failure were concluded to be 1) the relaxation of stresses induced during lamination, 2) moisture ingress from the sides of the samples and 3) moisture ingress at positions where the barrier had been damaged due to the topology of the sample.

Perovskite based photovoltaic (PV) devices have gained enormous importance due to their high power conversion efficiencies and ease of fabrication (solution processing). Conventionally, flexible solar cells have been reported on substrates like PET and PEN. Corning® Willow® Glass, owing to its superior processability and oxygen and moisture barrier property, is a potential replacement for these substrates. In this work, devices fabricated on Willow Glass substrates have been subjected to bending and fatigue tests to assess their worthiness as substrates for flexible solar cells.

The shipping bag used in semiconductor industry is very important as a protection guard of products. It provides good protection for finished products after shipping and the handling by the final users. Among various shipping bags, Moisture Barrier Bag (MBB) is the most widely used type in the semiconductor industry because of its high reliability. However, with the technology advancement, the packing of a large size of IC wafers is inevitable, which brings a new challenge to its resistance to a greater load of shipping and dropping. To reduce the failure rate of MBB leakage during shipment, we evaluate the physical and tensile strength of the shipping bag composed of different films. We significantly improved MBB by optimizing its raw material, which is the first time such approach with plausible results is reported.

In this work a novel and relatively inexpensive test technique is developed for characterizing moisture barrier performance of the edge seal in PV modules in a manner that is decoupled from other components of the PV module. A theoretical framework is developed to conjecture appropriate equations and functional forms for moisture breakthrough time in accelerated tests as well as in the field for an edge seal with desiccant embedded in it. Results from accelerated testing are shown to fit the proposed functional forms under various conditions thereby validating the theoretical framework. These equations and functional forms enable the prediction of long term moisture barrier performance of the edge seal using historical meteorological data (TMY data) in conjunction with results from accelerated tests. In the specific case of edge seal tested on certain MiaSole glass-glass modules these results establish that the edge seal considered is sufficient to prevent moisture ingress in the module, beyond the intended service life of the module, even for the most aggressive environmental conditions evaluated in this study. Further this study identifies paths to extend this work to the more complex structure involved in building CIGS based flexible products.

Parallel to rapid prototype testing for moisture barrier performance, extensive failure mode analyses of inorganic direct cell coatings for CIGS solar cells have led to important conclusions regarding barrier degradation during exposure. Based on these analyses, a new strategy for direct cell barrier film technology has been developed that eliminates the primary root causes of failure. This approach provides exceptional damp heat stability to CIGS devices, even in the absence of additional encapsulation technology. Evaluation of time-to-failure data resulted in characteristic lifetime estimates of >1500 h at 85°C/85% RH for the new barrier film approach, compared to ∼500 h for various silicon nitride based films under the same conditions. In fact, laboratory scale CIGS devices with the improved direct cell coating show >70% probability of surpassing 1000 h under damp heat stress and several cells have survived >3000 h under these conditions with less than 10% reduction in efficiency.

Single or double layers of Al 2 O 3 deposited by atomic layer deposition are shown to be excellent transparent front moisture barriers for CuInGaSe 2 devices. We studied two configurations; one where the Al 2 O 3 was deposited directly on the substrate, and the other where it was deposited onto a flexible UV-PET and laminated on to the substrate. We have exposed samples with ALD barrier, and other barriers for comparison, to accelerated degradation including 1000 hr damp-heat, 1200 hour UV, and 10 freeze-thaw cycles. The V OC and FF are essentially unaffected for cells with the ALD barrier, indicating it is highly effective in preventing moisture from reaching the junction of the CuInGaSe 2 cells. The JSC decreases due to yellowing of an epoxy which was used to bond the encapsulant to the substrate for these experimental devices. This is unrelated to the ALD barrier. The excellent stability in D-H exposure indicates the 55 nm ALD layers, directly applied to the device with 3 µm high grids, has very good conformal coverage.

The selection of components for computer integrated circuits (ICs) has been a major reliability problem in the past few years. The author argues that the present approach of using plastic ICs in MIL designs without a moisture barrier to correct possible package defects is a major risk. Vendor data for the reliability prediction value is usually overstated and may effect expected results of reliability testing. He details how screening reliability can be increased by the use of coated plastic parts.

The short service life of underground residential distribution (URD) cables has led to the development and evaluation of new insulators and cable designs. Some basic comparisons are made between the ethylene-propylene rubber (EPR) and cross-linked polyethylene (XLPE) families of primary cable insulation. Current insulation systems are briefly described, treeing and water-tree testing are discussed, and the performance of EPR and XLPE insulation is indicated. New design features, and their performance, are described. These features are: (1) improved insulation materials; (2) the use of 133% insulation levels in place of 100%; (3) jacketed constructions; (4) cable-in-conduit systems; (5) filled conductor strand; and (6) moisture barrier or moisture-blocked constructions. >

Many data have been reported relating to the electrical endurance of polymers. These data show that the performance is reduced by electrical and thermal stressing in wet conditions. In many present applications however, the cables function in their dry state since they include an effective moisture barrier. Thus it is important to also obtain information for endurance tests in dry environments. In this study a series of experiments have been performed which are designed to expand the time-scale of the available dry endurance data. The data reveal clear evidence of curvature. The electrokinetic endurance model yields the closest fit over all the data compared with either the inverse power law or the thermodynamic model.