Abstract: A built-up printed circuit board includes stacked micro via-holes, each of which is provided for interconnection between layers in the printed circuit board, and in each of which a filling material, such as liquefied resin or conductive paste, is filled using a poly screen of a general screen printing machine.

Abstract: Disclosed herein is a built-up printed circuit board with stacked micro via-holes, each of which is provided for interconnection between layers in the printed circuit board, and in each of which a filling material, such as liquefied resin or conductive paste, is filled using a poly screen of a general screen printing machine, and a method for manufacturing the same. The method comprises the steps of (a) forming a first via-hole through a first laminated copper sheet by means of a laser drill, (b) forming a first plated layer on the first via-hole and the first laminated copper sheet, (c) filling the first plated via-hole with a via-hole filling material, (d) forming a second plated layer on the first filled via-hole and the first plated layer to cover the first filled via-hole, (e) forming a second plated layer on the first filled via-hole and the first plated layer to cover the first filled via-hole, and (f) disposing a second laminated copper sheet on the second plated layer.

Abstract: A method is disclosed for controlling a pretilt angle direction for a liquid crystal cell comprising the steps of first setting the magnitude of pretilt angle and a plurality of pretilt angle directions in an alignment layer. This first step is achieved by irradiating linearly the alignment layer with polarized or unpolarized UV light. One of the plurality of pretilt angle directions is then selected by exposing the alignment layer to UV light a second time.

Abstract: A method and apparatus for inspecting solder joints are provided. A method for inspecting test solder joints includes the steps of illuminating the test solder joints on a printed circuit board to obtain sample images of the test solder joints by grabbing reflected light with a charge coupled device (CCD) camera, classifying the sample images by an inspector into a number of classes according to the soldering quality, inputting a specific sample image belonging to each class to a neural network to divide the class into a predetermined number of clusters; determining a synaptic weight of each class by learning each cluster, determining a confirmed synaptic weight by adjusting the synaptic weight according to a boundary condition between the clusters belonging to neighboring different classes, and selecting a similar cluster by comparing the similarities between the outputs of the neural network with respect to the test solder joints based on confirmed synaptic weights, and each output of the inspector's class.