Abstract:
A semiconductor device includes a board base having through-holes filled with a filling core, an additive layer provided on an upper surface of the board base as well as an upper surface of the filling core wherein the additive layer includes a wiring pattern having one or more paths, a semiconductor chip fixed on an upper surface of the additive layer, and nodes provided on a lower surface of the board base, wherein the one or more paths are laid out without a restriction posed by the through-holes, and are used for electrically connecting the semiconductor chip and the nodes.
Abstract:
A method of making a circuitized substrate such as a printed circuit board having at least one hole therein which comprises the steps of providing a layer of dielectric, forming at least one (and preferably several) holes therein, positioning a thin layer of support material atop the dielectric layer and over the hole(s), positioning a quantity of fill material on the thin layer of support material (preferably before positioning the thin layer on the dielectric) and thereafter applying a predetermined force sufficient to cause the thin support layer to rupture or otherwise deform (including melting from heat application thereto) such that the fill material is forcibly driven into the accommodating hole(s). Subsequent steps can include forming a layer of circuitry on the substrate's external surface and over the filled holes such that an electrical component such as a ball grid array (BGA), semiconductor chip, etc. may be directly positioned on and/or over the hole(s). A fill member usable with the method is also provided.
Abstract:
A novel method of filling apertures in substrates, such as through holes, is provided. The method utilizes a photoimageable film, and comprises the following steps: applying a photoimagable, hole fill film over the apertures; reflowing the hole fill film to flow into the apertures; exposing the hole fill film to actinic radiation, preferably ultraviolet light, through a phototool, which preferably has openings slightly larger than the diameter of the apertures; then at least partially curing the hole fill film; and developing the hole fill film to remove the unexposed hole fill film. An advantage of the present method is that the apertures may be selectively filled. After the apertures are filled, the hole fill film is cured, preferably by baking. Thereafter, the substrate is preferably subjected to further processing steps; for example, nubs of cured hole fill film are preferably removed. If desired, the substrate is circuitized. If desired, features are gold plated, such as for example, electrolessly gold plated. The hole fill film preferably has solids which comprise 0 to about 20% of a thixotrope and about 80% to about 100% parts of an epoxy resin system; the epoxy resin system comprises: from about 10% to about 80% of phenoxy polyol resin which is the condensation product of epichlorohydrin and bisphenol A, having a molecular weight of from about 40,000 to about 130,000; from about 20% to about 90% of an epoxidized multifunctional bisphenol A formaldehyde novolac resin having a molecular weight of from about 4,000 to about 10,000; from about 35% to about 50% of a diglycidyl ether of bisphenol A, preferably halogenated, and having a molecular weight of from about 600 to about 2,500; and from about 0.1 to about 15 parts by weight of the total resin weight, a cationic photoinitiator. The invention also relates to circuitized structures produced according to the method.
Abstract:
In order that popcorning and delamination resulting from moisture vapor in a semiconductor package may be prevented, a vent hole is formed in a die-bonding area of a plastic substrate so as to extend vertically through the substrate. An upper open end of the vent hole is covered with a solder resist film and a semiconductor chip is die-bonded on the solder resist film. In the die-bonding step, the solder resist film prevents an adhesive agent from flowing into the vent hole through the upper open end, so that gas permeability of the vent hole can be ensured. Furthermore, since the solder resist film has gas permeability, moisture vapor in the package is released outside through the vent hole and the solder resist film during a reflow heating.
Abstract:
It is to provide a multilayer printed circuit board having excellent resolution, interlaminar insulation property and resistance to cool-heat shock without forming unevenness on the surface and lowering peel strength even if the thickness of the resin insulating layer is thin. The invention proposes a multilayer printed circuit board comprising an upper conductor circuit layer, a lower conductor circuit layer and a resin insulating layer electrically insulating both the conductor circuit layers, in which the resin insulating layer is a composite layer comprised of an layer made from a heat-resistant resin hardly soluble in acid or oxidizing agent as a lower layer and an adhesive layer for electroless plating made from a heat-resistant resin as an upper layer, and if necessary, a resin is filled in a concave portion created between conductor insulating circuits of the lower layer so as to render the surface into the same plane as the surface of the conductor circuit.
Abstract:
A method of making a circuitized substrate wherein fill material is forced into the substrate's holes to thus provide additional support for conductive circuitry or the like thereon, thus increasing the final product's circuit density. The fill is provided in a substantially uncured state, following which partial cure occurs. Thereafter, the fill is substantially fully cured and the aforementioned circuit elements may then be provided directly thereon. Alternatively, a dual fill process is used with both quantities of uncured fill being disposed in each hole and then cured by a singular UV exposure step.
Abstract:
An electronics package includes a substrate, a via and a solder ball. The substrate has first and second opposed surfaces. The via is located within the substrate and terminates at the first surface. The via defines an opening having first and second opposed walls. The solder ball is at least partially located over the opening. The solder ball has first and second opposed sides, the first side being adjacent the first wall and the second side being adjacent the second wall. The first side is nearer to the first wall than the second side is to the second wall.
Abstract:
A process of manufacturing a printed circuit board having plated landless through-holes involves filling a radiation curable putty material in through-holes plated with copper in a substrate, exposing the material under radiation of light in order to cure the material, placing a liquid resist on the substrate surface, covering a mask over the resist, exposing the resist layer by using a mask having a circuit pattern, developing the resist, etching the substrate surface, and removing the cured putty material in the through-holes and the remaining portion of the resist. The filling material composition used in the process comprises hydrophthalic mono ester compound as a component (A), a catalyst for promoting photo polymerization of a vinyl group in the mono ester as a component (B), a highly transparent rosin having a Hazen color tone of 300 or less for the improvement of cure depth of the material after exposure of light as a component (C), and a powder of at least one extender selected from polyethelene, nylon, polyester, talc, silica, aluminum hydroxide, titanium oxide, barium sulfate, kaolinite, calcium carbonate, and phthalocyanine as a component (D).
Abstract:
A process of laminating a large-layer-count (LLC) substrates includes formation of first and second vias through respective substrates. A conductive path is formed through each of the respective vias, and posts are formed on the respective vias, electrically connected to the respective conductive path. A non-flowable adhesive layer having an aperture is provided between the LLC substrates so that the posts confront each other through the aperture. The LLC substrates are pressed together through the non-flowable adhesive layer to mechanically bond them together, and so that the posts abut each other. Simultaneously, the posts are electrically bonded to each other in the aperture.
Abstract:
A ball grid array (BGA) integrated circuit package which has a plurality of elliptically shaped solder pads located on a bottom surface of a package substrate. The bottom surface also has a solder mask which contains a number of holes that expose the solder pads. The holes allow solder balls to be attached to the solder pads. The solder balls can be reflowed to attach the package to a printed circuit board. The elliptical shaped solder pads have a width that is smaller than the length of the pads. The narrow pad portions provide additional routing space for the bottom surface of the package. The solder mask hole diameters are less than the lengths of the solder pads so that portions of the pads are anchored by the maskant material. The anchored portions increase the peel strength of the pads.