Characterization and improvement of copper / glass adhesion

The development of glass substrates for use as an alternative to printed circuit boards (PCBs) attracts significant industrial attention, because of the potential for low cost but high performance interconnects and optical connection. Electroless plating is currently used to deposit conductive tracks on glass substrates and the quality of copper / glass adhesion is a key functional issue. Without adequate adhesive strength the copper plating will prematurely fail. Existing studies have covered the relationship between surface roughness and adhesion performance, but few of them have considered the detail of surface topography in any depth. This research is specifically considering the mechanical contribution of the glass surface texture to the copper / glass adhesive bond, and attempting to isolate new ISO 25178 areal surface texture parameters that can describe these surfaces. Excimer laser machining has been developed and used to create a range of micro pattern structured surfaces on CMG glass substrates. Excimer mask dimensions and laser operation parameters have been varied and optimized according to surface topography and adhesion performance of the samples. Non-contact surface measurement equipment (Zygo NewView 5000 coherence scanning interferometry) has been utilized to measure and parameterize (ISO 25178) the surface texture of the glass substrates before electroless copper metallization. Copper adhesion quality has been tested using quantitative scratch testing techniques, providing an identification of the critical load of failure for different plated substrates. This research is establishing the statistical quality of correlation between the critical load values and the associated areal parameters. In this thesis, the optimal laser processing parameter settings for CMG glass substrate machining and the topographic images of structured surfaces for achieving strong copper / glass plating adhesion are identified. The experimental relationships between critical load and areal surface parameters, as well as the discussions of a theoretical approach are presented. It is more significant to consider Sq, Sdq, Sdr, Sxp, Vv, Vmc and Vvc to describe glass substrate surface topography and the recommended data value ranges for each parameter have been identified to predict copper / plating adhesion performance

The assessment of areal surface texture parameters for characterizing the adhesive bond strength of copper plated micro-machined glass.

The micro-electronics industry is investigating glass as an alternative printed circuit board material and interposer. Electroless copper plating of glass is required for tracks and interconnects, but understanding of how the surface topography of the glass substrate affects the mechanics of the copper/glass bond quality is limited. Areal surface texture parameters provide the potential for characterizing key surface features associated with improving copper/glass bonding. Laser ablation techniques have been used to prepare glass surfaces with micro-scale structured features, and these features have been quantified using areal parameters. The copper/glass bond strength has been quantified using scratch testing techniques, with statistical analysis identifying strongly correlating areal parameters that may be used for predictive design of glass surfaces

The use of areal surface texture parameters to characterize the mechanical bond strength of copper on glass plating applications

This report describe research into the role that surface topography plays in influencing the mechanical bond strength of the electroless copper plating of novel glass substrates. The work considers bespoke laser machining of glass substrates, electroless plating chemistry, areal surface topography analysis using non-contact optical techniques, paramaterization of the surfaces using ISO 25178 areal parameters, and scratch testing of plated copper to measure the adhesive bond strength. By correlating bond strength to appropriate areal parameters, it is anticipated that better mechanical adhesive potential of machined glass surfaces can be achieved

Transcriptional and Post-Transcriptional Mechanisms for Oncogenic Overexpression of Ether À Go-Go K+ Channel

The human ether-à-go-go-1 (h-eag1) K+ channel is expressed in a variety of cell lines derived from human malignant tumors and in clinical samples of several different cancers, but is otherwise absent in normal tissues. It was found to be necessary for cell cycle progression and tumorigenesis. Specific inhibition of h-eag1 expression leads to inhibition of tumor cell proliferation. We report here that h-eag1 expression is controlled by the p53−miR-34−E2F1 pathway through a negative feed-forward mechanism. We first established E2F1 as a transactivator of h-eag1 gene through characterizing its promoter region. We then revealed that miR-34, a known transcriptional target of p53, is an important negative regulator of h-eag1 through dual mechanisms by directly repressing h-eag1 at the post-transcriptional level and indirectly silencing h-eag1 at the transcriptional level via repressing E2F1. There is a strong inverse relationship between the expression levels of miR-34 and h-eag1 protein. H-eag1antisense antagonized the growth-stimulating effects and the upregulation of h-eag1 expression in SHSY5Y cells, induced by knockdown of miR-34, E2F1 overexpression, or inhibition of p53 activity. Therefore, p53 negatively regulates h-eag1 expression by a negative feed-forward mechanism through the p53−miR-34−E2F1 pathway. Inactivation of p53 activity, as is the case in many cancers, can thus cause oncogenic overexpression of h-eag1 by relieving the negative feed-forward regulation. These findings not only help us understand the molecular mechanisms for oncogenic overexpression of h-eag1 in tumorigenesis but also uncover the cell-cycle regulation through the p53−miR-34−E2F1−h-eag1 pathway. Moreover, these findings place h-eag1 in the p53−miR-34−E2F1−h-eag1 pathway with h-eag as a terminal effecter component and with miR-34 (and E2F1) as a linker between p53 and h-eag1. Our study therefore fills the gap between p53 pathway and its cellular function mediated by h-eag1

A comparison between profile and areal surface roughness parameters

Surface roughness has an important influence on the service performance and life of parts. Areal surface roughness has the advantage of accurately and comprehensively characterizing surface microtopography. Understanding the relationship and distinction between profile and areal surface roughness is conducive to deepening the study of areal surface roughness and improving its application. In this paper, the concepts, development, and applications of surface roughness in the profile and the areal are summarized from the aspect of evaluation parameters. The relationships and differences between surface roughness in the profile and the areal are analyzed for each aspect, and future development trends are identified

Study on the Performances of an Approximating Spline Filter Based on the ADRF Function in Surface Roughness Evaluation

Isotropy is an important feature of an area filter in the three-dimensional surface roughness evaluation. First, the transmission characteristic deviation between the approximating spline filter and the Gaussian filter is reduced by cascading approximating. Second, the approximating spline filter is superimposed on the orthogonal direction to obtain an isotropic areal filter. Then, four direct methods for the solving approximating spline matrix are applied. Based on the profile filtering and areal filtering, the computational efficiency and accuracy are compared. The experimental results show that the improved square root method (LDLT decomposition) combines both computational efficiency and filtering precision, and is a good choice for solving the approximating spline matrix. Finally, six kinds of robust approximating spline filters are constructed. Taking the output value of robust Gaussian regression filter (RGRF) as reference, and the honing profile and step surface with deep valley characteristics were used as test surfaces to compare their robustness and iteration time. The experimental results show that the approximating spline filter based on the ADRF function has the shortest iteration times, while its roughness is close to the robust Gaussian regression filter

Platform pricing and blockchain adoption for capacity sharing with cross-network externality and supply risk

Platform-based capacity sharing is a new business format of sharing economy to reallocate spare production resources via industrial internet, generating collaborative manufacturing related platform operations issues. This paper examines the impact of cross-network externality and supply risk of the two-sided market on the pricing and blockchain adopting decisions of capacity sharing platforms. The mean–variance model is employed to depict the impact of purchasers’ or suppliers’ risk-sensitive types on platform pricing, where purchasers’ or suppliers’ risk-sensitive types can be identified by blockchain technology and be intertwined by the cross-network externality. The obtained platform’s optimal pricing under two scenarios with risk-sensitive capacity purchasers (D) and risk-sensitive suppliers (S) shows that the platform charges risk-seeking, risk-neutral and risk-averse users in descending order for the platform side containing risk-sensitive users, regardless of the comparison of bilateral cross-network externalities. However, for risk-neutral side users, the price ranking under three risk-sensitive types depends on the relative size of bilateral cross-network externalities. In addition, blockchain technology always decreases the surplus of risk-sensitive side users, whereas it increases the surplus of risk-insensitive side users. Further, we find that platform prefers to introduce blockchain technology when the fixed cost of introducing it is less than the profit increment it brings. In addition, by comparing platform profits and blockchain value in the two scenarios, we argue that platforms need to comprehensively balance the comparison of fixed costs of introducing blockchain on both sides and the importance of risk-preferring and risk-averse users to improve their profitability. Introducing blockchain technology to the side where the cost of blockchain technology is higher may result in higher blockchain value for the platform. Finally, we examine the platform with two-sided risk-sensitive users and the results are robust. This study proposes theoretical explanation for platform pricing considering the cross-network externality and risk-sensitive users, as well as some management insights for the application of blockchain technology in platform operations