Abstract: A deformable wheel assembly according to the present invention is characterized by comprising: a main frame provided with a main driving shaft that is connected to and rotated by a driving means of a driving body including a vehicle; a rotation driving unit which is provided on the main frame and connected to the driving means, and provides rotational power separately from the main driving shaft; an extendable driving unit provided on the main frame and connected to the driving means; and a link unit which is provided on the main frame and forms the outer shape of a wheel, and changes the shape of the wheel into a deformed shape including a circular or elliptical shape by the operation of the extendable driving unit. The rotation driving unit is connected to a wheel unit and provides rotational power separately from the main driving shaft.

Abstract: A method for fabricating a printed circuit board includes the steps of: fabricating a printed circuit board having at least one collapsed portion; depositing a first solder resist in the collapsed portion; exposing the first solder resist-coated printed circuit board at a pressure lower than atmospheric pressure for a predetermined time; coating a second solder resist on the entire surface of the printed circuit board; and drying and hardening the first and the second solder resists. With this method, when a solder resist is coated, since an air space does not remain in a blind via hole, the reliability of the attachment between a printed circuit board and the solder resist layer is increased.

Abstract: A multi-layer printed circuit board includes a core layer having a first circuit patterns formed on the upper and lower surface of a first insulation layer and via-holes in which a conductive layer is formed to electrically connect with the first circuit patterns. Built-up layers are formed on the upper and lower side of the core layer and have second circuit patterns electrically connected with the first circuit pattern by means of a via-holes in which conductive layers are formed to electrically connect the first circuit patterns of the core layer and the second circuit patterns of the upper and/or lower built-up layers. The via-holes in the core layer and the via-holes in the built-up layers are formed from an each side/both sides of the core layer and from the built-up layers toward the core layer, whereby interconnection of the circuit patterns is obtained without using through-holes and permitting shortening of the wiring and higher integration.

Abstract: A method for fabricating a printed circuit board includes the steps of: fabricating a printed circuit board having at least one collapsed portion; depositing a first solder resist in the collapsed portion; exposing the first solder resist-coated printed circuit board at a pressure lower than atmospheric pressure for a predetermined time; coating a second solder resist on the entire surface of the printed circuit board; and drying and hardening the first and the second solder resists. With this method, when a solder resist is coated, since an air space does not remain in a blind via hole, the reliability of the attachment between a printed circuit board and the solder resist layer is increased.