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The connection between different layers is usually realized through vertical metallized holes. When the number of PCB layers increases, the interconnection between different layers are complex. Any layer interconnection processing technology is required. The processing technology is complex and has high cost. This paper presents a new method to achieve arbitrary layer interconnection. The transition of quasi-coaxial between two composite boards is realized by BGA. This method simplifies the interconnection between microwave boards of any layer. The test of sub-array microwave boards connected by BGA proves that the interconnection meets the engineering requirements. simplifies the manufacturing process and reduces the manufacturing cost.

Objective To compare the efficacy of several antiseptics in decreasing the blood culture contamination rate. Design Network meta-analysis. Data source Electronic searches of PubMed and Embase were conducted up to November 2015. Only randomized controlled trials or quasi-randomized controlled trials were eligible. We applied no language restriction. A comprehensive review of articles in the reference lists was also accomplished for possible relevant studies. Review methods Relevant studies evaluating efficacy of different antiseptics in venous puncture site for decreasing the blood culture contamination rate were included. The data were extracted from the included randomized controlled trials by two authors independently. The risk of bias was evaluated using Detsky scale by two authors independently. We used WinBUGS1.43 software and statistic model described by Chaimani to perform this network meta-analysis. Then graphs of statistical results of WinBUGS1.43 software were generated using ‘networkplot', ‘ifplot', ‘netfunnel' and ‘sucra' procedure by STATA13.0. Odds ratio and 95% confidence intervals were assessed for dichotomous data. A probability of p less than 0.05 was considered to be statistically significant. Compared with ordinary meta-analyses, this network meta-analysis offered hierarchies for the efficacy of different antiseptics in decreasing the blood culture contamination rate. Results Seven randomized controlled trials involving 34,408 blood samples were eligible for the meta-analysis. No significant difference was found in blood culture contamination rate among different antiseptics. No significant difference was found between non-alcoholic antiseptics and alcoholic antiseptics, alcoholic chlorhexidine and povidone iodine, chlorhexidine and iodine compounds, povidone iodine and iodine tincture in this aspect, respectively. Conclusions Different antiseptics may not affect the blood culture contamination rate. Different intervals between the skin disinfection and the venous puncture, the different settings (emergency room, medical wards, and intensive care units) and the performance of the phlebotomy may affect the blood culture contamination rate.