TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The layer (a1) is a first outer layer comprising either interpolymerized units of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride or interpolymerized units of tetrafluoroethylene and ethylene, where the fluoropolymer has a tensile modulus of less than 100000 psi. The layer (a2) is an intermediate layer, where the polyethylene terephthalate has at least two planar directions and a shrinkage of less than 1% in each planar direction when held for 15 minutes at 150 degrees C measured in accordance with ASTM 2305-02. The multilayer, integrated film further comprises: a second outer layer of an olefinic polymer having a structure of formula (CH2=CHR1); a top layer including cross-linked polyethene homopolymers or copolymers, where the cross-linked polyethene homopolymers or copolymers comprises polyethene copolymers comprising more than 99 mole% of repeating units derived from ethene and polyethene copolymers comprising at least 50 mole% of repeating units derived from ethene and further including one or more alkene comonomers; a tie layer arranged between the first outer layer and the intermediate layer and/or the second outer layer and intermediate layer; and at least one of flame retardants and anti-dripping agents. The first and second outer layers are bonded to opposing sides of the intermediate layer. The intermediate layer has first and second surfaces. The second outer layer comprises interpolymerized units of ethylene vinyl acetate. The thickness of the second outer layer is greater than or twice the combined thickness of the first outer layer and the intermediate layer. The thickness of the backsheet portion is greater than 15 mils. The fluoropolymer has a tensile modulus of less than 80000 psi. The shrinkage of the backsheet portion is less than 1% at 150 degrees C when held for 15 minutes measured in accordance with ASTM 2305-02. The backsheet portion and the encapsulant portion are coextruded or bonded together. The plasticizer in the encapsulant portion: is non-polar; comprises ethylene/ alpha -olefin copolymers and 4-10C polyolefin homopolymers; has a glass transition temperature (Tg) of less than -50 degrees C, preferably less than -70 degrees C; and is liquid at 20 degrees C. The polyolefin in the encapsulant portion is an ethylene/ alpha -olefin copolymer. The alpha -olefin moiety of the ethylene/ alpha -olefin copolymer includes four or more carbons. The ethylene/ alpha -olefin copolymer is (Q) a low crystalline ethylene/a-olefin copolymer, preferably a butene alpha -olefin, having a differential scanning calorimetry peak melting point of less than or equal to 50 degrees C. The encapsulant portion includes greater than 70 wt.% of (Q). The silane in the encapsulant portion is an unsaturated alkoxysilane, preferably an acrylic alkoxysilane. The cross-linking agents in the encapsulant portion are a thermal curative (preferably a peroxide) and/or a photo-curative. The encapsulant portion: further includes a coagent, and an additional resin; and has multiple layers. The additional resin is an additional (Q) or an ethylene/butene copolymer and an ethylene/octene copolymer.R1 = H or 1-18C alkyl.