Distance from neutral point

Overall Dimensions and Distance from Neutral Point (DNP). Package size continues to grow as the number of FOs increase to meet the demands of ever increasing IC functionality. As IC complexity increases, memory is embedded in devices, while as silicon feature sizes decrease, FO counts continne to be driven upward. Package dimensions have surpassed 50 mm. Package layer counts for both ceramic and plastic material sets continue to increase rapidly. 

FIGURE 58.25 Distance from Neutral Point (DNP) tor a BGA-type package. The DNP increases when moving away from the center (center line) of the package. Pitch is also indicated in this diagram. Pitch is defined as the center-to-center distance between two adjacent interconnects (in this example, between two adjacent solder balls). 

Piezoelectricity is a physical effect exhibited by crystals that are electrically neutral, but that do not have a center of reflective symmetry in crystal structure. The essential property of a point of reflective symmetry is that for each atomic position in the crystal lattice there is a matching atomic position at a point that is directly opposite the first with respect to the point of symmetry this second position is at a same distance from the point of symmetry as the first. For example, the face-centered cubic structure has a point of reflective symmetry at the geometrical center of the unit cell whereas the cubic zinc blende structure does not have a center of symmetry. 

If the total length of drill collar string would be, for example, 330 ft, then the number 232 ft would indicate the distance from the bit to the neutral point. 

The sign of V(r) at any point in space depends on whether the nuclear contribution (positive) or the electronic (negative) dominates. For neutral, spherically-averaged free atoms, V(r) is positive everywhere, decreasing monotonically with radial distance from the nucleus [3, 4]. When atoms interact to form molecules, however, the concomitant polarization of their charge distributions (relatively minor but very important) results in the development of regions of negative potential. These occur primarily... 

Figure 2.26. The component of the chain end-to-end distance normal to a surface as a function of the distance from the surface at which the chain starts, normalised by the bulk end-to-end distance. Points are from a lattice Monte Carlo simulation of a polymer melt in contact with a neutral wall (o, N — 100 A, = 50), whereas the line is the analytical prediction for random walks with a reflecting boundary condition. After Bitsanis and Brinke (1993).

This is really the same as the theory proposed by Grotthuss (see p. 25), who is not mentioned. His paper was first published in an accessible form only in 1806 and Davy had probably not seen it, but he does not mention Grotthuss in a later paper. Davy (XI, v, 21, 42) assumed that the attraction of a pole decreases in strength as far as the mid-point between the two poles, which place is neutral. Grotthuss had assumed a constant force between the poles. Some experiments by Davy which seemed to show a diminished decomposition at a greater distance from a pole could not be confirmed by Faraday.2... 

Purity, excitation n. Ratio of the straight line distance on a CIE chromaticity diagram between the chromaticity point of the sample and the achromatic or illuminant point on the diagram, to the linear distance between the point of intersection of this line with the spectrum locus and the illuminant point. It is properly designated as Pg, but is frequently abbreviation simply as P The excitation purity, then, describes the relative distance from the neutral point and roughly corresponds in concept to the psychological description of saturation or chroma. 

Section modulus Z) n. In a beam under load, the quotient of the moment of inertia of the beam s cross-section about its neutral axis divided by the distance from the neutral axis to the outermost surface of the beam He). The bending moment divided by the section modulus gives the maximum stress in the beam at any point along it. 

In bending operations, the length of the blank before bending has to be calculated. Any metal which is bent will stretch on the outside of the bends and be compressed on the inside. At some point between the inside and outside faces, the layers remain unaltered in length and this point is known as the neutral axis. For bends of radius more than twice the material thickness, the neutral axis may be assumed to lie at the centre of the material thickness, Fig. 17.10(a). For sharper bends of radius less than twice the material thickness, the neutral axis shifts towards the inside face. In this case, the distance from the neutral axis to the inside face may be assumed to be 0.33 times the material thickness, Fig. 17.10(b). 

The atomic radii describe the characteristic size of the neutral and isolated atoms that are not involved in any kind of bonds. The radins of the free atom is considered the distance from the nucleus to the point of maximnm electron radial density of the occnpied atomic orbital. 

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