Abstract: A micro electrical mechanical system device includes a frame portion having an upper surface with a rectangular shape; a functional element; a beam portion extending from one of sides of the frame portion toward an opposite one and having a first side surface, a second side surface opposite to the first side surface, and upper and lower surfaces between the first and second side surfaces; and a movable portion supported on the beam portion inside the frame portion to be movable. The beam portion includes a constricted portion formed in the first side surface and the second side surface along the functional element, and having a main surface and two side surfaces facing each other. The movable portion includes a center portion having four corner portions and protruding portions extending from the corner portions and away from the frame portion and the beam portion.

Abstract: The present invention provides a method of manufacturing a semiconductor chip formed with an adhesive film at a back surface thereof, comprising the steps of applying a die bond material onto a dummy wafer by a spin coat method to form a coating film, bonding a back surface of a semiconductor wafer onto the coating film of the die bond material formed over the dummy wafer, performing fractionalization for dividing the semiconductor wafer to form pieces, and peeling off the pieces from above the dummy wafer and transferring the coating film of the die bond material to back surfaces of the pieces to form adhesive films.

Abstract: An optical storage medium has a substrate having a first surface and a second surface on both sides, the first surface allowing light to pass therethrough in recording or reproduction. The medium also has at least one composite layer having at least a first protective film, a second protective film and a recording film formed in order on the second surface, the first and second protective films exhibiting refractive indices n1 and n2, respectively, having the following relations therebetween, to the light having a specific wavelength ?: n1>n2, n1?n2?0.02 and 2.1?n1?2.5, 1.5?n2?2.1. The composite layer may have at least a first protective film, a second protective film, a third protective film and a recording film formed in order on the second surface, the first, second and third protective films exhibiting refractive indices n21, n22 and n23, respectively, having a relation n21>n22>n23 or n22>n21>n23 thereamong, to the light having a specific wavelength ?.

Abstract: A holographic recording medium 1 includes a holographic recording layer 7 having information recorded by use of recording beams L1, L2 and a two-state variable layer 5 arranged on one side of the holographic recording medium 1 where the recording beams L, L2 radiate from the holographic recording layer 7. In the holographic recording medium 1, the two-state variable layer 5 is made from a material whose state can be changed from a first state to a second state by receiving a light and whose reflectivity can be changed from a first reflectivity corresponding to the first state to a second reflectivity corresponding to the second state. The second reflectivity is higher than the first reflectivity.

Abstract: An integrally micromachined acceleration sensor has a mass with a surface facing a stopper. At least one protrusion projects from this surface toward the stopper. In the absence of acceleration, the protrusion is spaced apart from the stopper, but by limiting motion of the mass toward the stopper, the protrusion improves the shock resistance of the acceleration sensor. The protrusion also prevents the mass from sticking to the stopper during the fabrication process. The stopper may have a pattern of holes surrounding the protrusion, so that the protrusion is produced naturally during the wet etching process that separates the mass from the stopper. The holes also shorten the wet etching time.

Abstract: An optical disc has a first transparent substrate and a second substrate. The first substrate has a first surface and an opposing second surface. The first surface is a beam incidence surface for a laser beam in recording or reproduction of data. The second surface has first concave sections and first convex sections alternately formed thereon. The first concave sections are closer than the first convex sections to the beam incidence surface. The first convex sections have first top portions and first bottom portions closer than the first top portions to the beam incidence surface. First pre-pits carrying auxiliary information related to the data is formed on the first top portions. Each first top portion has a first width orthogonal to a direction of tracks on the first substrate. A second width orthogonal to the above direction between two first top portions of adjacent first convex sections having a first concave section therebetween is narrower than the first width.

Abstract: Single crystals of tetrabromobisphenol A having an average particle size of from 150 to 500 .mu.m, each having a polyhedral shape.

Abstract: A method for preventing agglomeration of powder, characterized in that a poly(oxyethylene)diglycosic acid is incorporated as an anti-agglomeration agent to the powder.

Abstract: A process for preventing the agglomeration of agglomerative powder, such as TEDA monomer piperazine, sodium chloride and ammonium chloride, comprising adding TEDA polymer to the agglomerative powder or adding TEDA to a solution from which the powdery material is crystallized.