Abstract:
A substrate for a laminate which comprises a nonwoven fabric which is composed mainly of a liquid crystal polyester fiber, and which is subjected to (1) an entangling treatment, (2) a heating treatment to impart adhesivity to a thermosetting resin, and (3) a surface-modifying treatment, and a laminate containing at least one prepreg prepared by impregnating the substrate with a thermosetting resin and drying are disclosed. The substrate of the present invention has low dielectric constant, is light, exhibits low hygroscopicity, and has good properties to be impregnated with the thermosetting resin and good adhesiveness to the thermosetting resin.
Abstract:
An electrical substrate material is presented which comprises a thermosetting matrix which includes a polybutadiene or polyisoprene resin and an unsaturated butadiene or isoprene containing polymer in an amount of 25 to 50 vol. %; a woven glass fabric in an amount of 10 to 40 vol. %; a particulate, preferably ceramic filler in an amount of from 5 to 60 vol. %; a flame retardant and a peroxide cure initiator. A preferred composition has 18% woven glass, 41% particulate filler and 30% thermosetting matrix. The foregoing component ratios and particularly the relatively high range of particulate filler is an important feature of this invention in that this filled composite material leads to a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. In addition, another important feature of this invention is the low amount of glass fabric filler relative to the higher range of particulate filler which leads to improved (lower) CTE in the Z axis or thickness direction, improved electrical performance (e.g., dissipation factor), lower cost and the ability to tailor dielectric constant through appropriate selection of particulate fillers.
Abstract:
Dimensionally stable resin impregnated laminates for printed wiring board applications are reinforced with from 43 to 57 weight percent of nonwoven aramid sheet having a coefficient of thermal expansion of less than 10 ppm per .degree. C, a basis weight of from 0.8 to 4.0 oz/yd.sup.2, a density of from 0.5 to 1.0 g/cc and a Gurley Hill Porosity of less than 10 sec.
Abstract:
A method for manufacturing a multilayer laminate provides in metal plates each forming a substrate apertures at positions where through holes are to be formed, fills the apertures with a synthetic resin including a first filler, and prepares prepregs to be disposed on both sides of each substrate by impregnating nonwoven fabric with a thermosetting synthetic resin containing a second filler. The metal plates forming the substrates are thereby allowed to be thicker for realizing larger capacity power supply with an improvement also in heat dissipation characteristics.
Abstract:
A flexible sheet which comprises a non-woven fabric made predominantly from a poly(aromatic amide) component which is impregnated with a heat- and/or light-curable resin, wherein the non-woven fabric satisfies the following conditions:5 g/m.sup.2
Abstract:
A multilayer printed circuit board comprising a laminate of at least one glass fiber nonwoven cloth layer impregnated with thermosetting resin and glass fiber woven cloth layers impregnated with thermosetting resin, the laminate having a pair of V-cut grooves formed therein so that only the glass fiber nonwoven cloth layer remains uncut whereby the multilayer printed circuit board can be divided at the uncut glass fiber nonwoven cloth layer along the V-cut grooves into a plurality of printed circuit board portions which can be mounted having a practical size.
Abstract:
A flexible sheet which comprises a non-woven fabric made predominantly from a poly(aromatic amide) component which is impregnated with a heat- and/or light-curable resin, wherein the non-woven fabric satisfies the following conditions:5 g/m.sup.2
Abstract translation:一种柔性片材,其包含主要由浸渍有热和/或光可固化树脂的聚(芳香族酰胺)成分制成的无纺织物,其中所述无纺布满足以下条件:5g / m 2 单位面积重量<35g / m 2,0.15g / cm 3密度<0.8g / cm 3,具有良好的平衡性,例如优异的热尺寸稳定性,耐热性(耐焊接性),耐水性 ,耐溶剂性,电绝缘性能和机械性能,并且可用于制备柔性印刷电路板,以及其用于柔性覆金属层压板和柔性印刷电路板的用途。
Abstract:
Disclosed are improved laminates useful in the manufacture of multi-layer printed wiring boards (MLPWB) and laminates. Such improved composites contain at least one layer which is formed from a liquid crystal polymer selected from the group consisting of poly(para-phenylene benzobisthiazole), poly(paraphenylene benzobisoxazole), poly(2,5-benzothiazole), poly(2,5-benzoxazole), and mixtures thereof. The presently preferred liquid crystal polymer comprises poly(para-phenylene benzobisthiazole). The negative coefficient of thermal expansion and high modulus of elasticity of the liquid crystal polymers enable a laminate and MLPWB to be manufactured therefrom having a tailored coefficient of thermal expansion, broadly ranging from about 0 to 15 ppm/.degree. C. MLPWBs constructed of polymeric core layers also are possible utilizing the preferred liquid crystal polymers of the present invention.
Abstract:
High density para-aramid papers comprising 5 to 25 percent, by weight, binder and an amount of para-aramid fibers selected from the group consisting of para-aramid pulp, para-aramid floc and mixtures thereof, compacted to provide a volume percent para-aramid fiber of at least 53 minus 0.13 times the volume percent floc in the paper are useful in the preparation of circuit board substrates having a low coefficient of thermal expansion.
Abstract:
A laminated board lined with thermally and electrically conductive material, which comprises:(a) a prepreg sheet formed of an alumina paper made from a mixture of alumina fibril, as the principal component, having a fiber diameter of 100 microns or smaller and a fiber length which is ten times or more as long as the fiber diameter, and microfibrillar organic fiber as a binding agent, and a thermosetting resin; and(b) an electrically conductive material in foil such as copper or aluminum bonded to said prepreg sheet.