Purpose -The purpose of this paper is to present a summary of development work made in technical centres and on the subsequent customer qualification of copper filled through holes and blind microvias. Design/methodology/approach -Various copper deposition parameters were investigated in a small-scale production line which was then extended to full-scale production qualification in a horizontal conveyorised system. Samples of substrates with copper filled through holes were qualified at end-user facilities. Findings -The copper plating process may be used to replace an existing production process for printed circuit boards. The proposed system can give a more reliable result in terms of filling and technical capability for the produced substrate. Overall production cost savings are possible.Research limitations/implications -The technology is based on a copper plating electrolyte using a redox pair for copper replenishment. The results achieved depend on use of this system and on production equipment which can control the redox system and copper concentration within a tight range. Originality/value -The paper shows how the use of a horizontal production system with redox copper replenishment can achieve filling of though holes and blind microvias with reduced surface plated copper thickness. Reduction in the use of copper saves both resources and also reduces production costs. The process is proposed as an alternative to existing paste plugging processes, which are both cost and labour intensive.
Hop production, like all other water uses in the area, is facing water availability concerns. Deficit irrigation may address water scarcity issues in hop production. This study quantifies the effect of deficit irrigation on hop yield, quality, water productivity and grower profitability. Mt. Hood, Columbus, Chinook and Willamette cultivars were grown under three irrigation levels; 60, 80 and 100% of the crop's irrigation requirement, using a sub-surface drip irrigation system. Results show that hop plants generally respond to water stress with yield reductions; compared to the 100% irrigation level, the 60% irrigation level caused reductions in total 2-year dry hop
Polymix breeding with paternity analysis (PMX/ WPA) has been proposed as an alternative to traditional full-sib breeding and testing schemes. To fully capture the benefits of PMX/WPA, differential reproductive success (DRS) of pollen parents used in the polymix must be modest. DRS was evaluated in an operational test of PMX/ WPA for a hybrid poplar breeding program. A 16-parent pollen polymix (Populus nigra L.) was used to pollinate seven clones of Populus deltoides (Bartr. ex. Marshall) under greenhouse breeding conditions. Progeny were grown out briefly and randomly sampled (357) prior to out-planting in field trials. Twenty-eight simple sequence repeat (SSR) loci were evaluated and 15 were selected for genetic characterization in small populations of three Populus spp (P. nigra, P. deltoides, and P. balsamifera spp trichocarpa Torr. & Gray). Seven loci were ultimately selected for paternity analysis of progeny. The average exclusion probability of the seven loci in P. nigra was 0.604; combined, the theoretical exclusion probability was 0.9999. However, only 95% of sampled progeny were unambiguously assigned a single paternal parent. Missing data likely accounted for most of the ambiguity. DRS was statistically significant though not prohibitive for practical utility of PMX/WPA as a breeding system. Of the 112 potential crosses in this study, 92 were represented. Eight of the 16 pollen parents contributed 83% of the progeny. Good pollen vigor, as measured by germination percent, did not ensure paternal success, but poor vigor was associated with lack of paternal success. PMX/WPA appears to be logistically and economically attractive for hybrid poplar breeding and testing.
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