High Density Interconnect Specifications

IPC 4104, Specification for High-Density Interconnect (HDI) and Microvia Materials, 05/99 This document contains specification sheets for materials used in HDI and microvia applications. 

IPC-6016 Standard for Qualification and Performance Specification for High Density Interconnection Structures ... 

IPC-4104 This standard identifies materials used for high-density interconnection structures. A series of specifications (slash sheets) are defined for specific available materials. Each sheet outlines engineering and performance data for materials used to fabricate high-density interconnecting structures. These materials include dielectric insulator, conductor, and dielectric/conductor combinations. The slash sheets are provided with letters and numbers for identification purposes. For example, if a user wishes to order from a vendor and reference the specification sheet number 1, the number 1 would be substituted for the S ... 

To facilitate the many choices of laminates and their associated properties, industry standards groups such as the IPC have defined minimum performance specifications and have issued several specifications to inform the selection process. Some of the most commonly used material specifications are those that deal with laminate,prepreg, and copper foil. IPC lOl, Specification for Base Materials for Rigid and Multilayer Printed Boards, and IPC-4652, Metal Foil for Printed Wiring Applications, are the primary specifications for clad laminates, prepregs, and foils. Another specification, IPC- 4104, Specification for High Density Interconnect (HDI) and Microvia Materials, deals with many of the new materials for HDI, such as epoxy-coated microfoils, as discussed in this chapter. 

IPC-6012, Qualification and Performance Specification for Rigid Printed Boards IPC-6013, Qualification and Performance Specification for Flexible Printed Boards IPC-6016, Qualification and Performance Specification for High Density Interconnect... 

IPC-4104 Specification for High Density Interconnect (HDI) and Microvia Materials... 

PolyHIPE materials possess many peculiar properties as a result of their unique cellular structure. Referring specifically to open-cell polymers (which have received the most attention in the literature), they are characterised by a very low dry bulk density, typically less than 0.1 gem-3, due to their highly porous, interconnected structure. 

Table 61.3 shows typical requirements for interconnection in the end product, and the preferred specification of circuit parameters for the use of high-density flexible circuits. 

The primary purpose of this section has been to show the possibilities for using density and area profile data to aid in the better understanding of gas-carbon reactions. In order to determine specific reaction rates and carbon dioxide concentrations at given penetrations, it has been necessary to make assumptions which can only be approximations to the truth. Several major anomalies in the results have been found, however. The calculated concentrations of carbon dioxide at the external surface of rods reacted at 1200 (Table VI) and 1305° are not in agreement with the known carbon dioxide concentrations. Clearly, more information is required on the variation of Deir with temperature and its variation with porosity produced at different reaction temperatures. It is feasible that at high temperatures, considerable porosity may be produced without increasing Deo to such a marked extent as found at 900°. Another anomaly is the non-uniformity of reaction found at 925°, when it would be expected that the reaction should be in Zone I. The preliminary assumption of a completely interconnecting pore system may not be valid. It should also be noted that neither the value of K in Equation (75) nor the low-temperature activa-... 

A nodular epoxy network is thought to be a two-phase system in which regions of relatively high crosslink density are dispersed in a less crosslinked interconnecting matrix. If this is true, then the nodules should exhibit properties different from those of the matrix, e.g., a higher Tg, and a different specific volume. It is also reasonable to expect that the size and concentration of nodules should be sensitive to variations in the reactant ratio and cure conditions. 

Matrix porosity on the order of 40% leads to overall porosity near 25%, resulting in the relatively low composite densities shown in Table 2. Specific surface area measurements of the GEN-IV composite show 30 m /g. This is 100 times greaterthan dense matrix CMC s and is indicative of fine interconnected porosity [30]. Such high matrix porosity is undesirable where hermetic fluid containment is required and also leads to concerns with use in erosive environments [76]. 

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