From 0be32596a1f66430e18213d07feef919f7b33fd6 Mon Sep 17 00:00:00 2001 From: jaseg Date: Mon, 10 Nov 2025 13:27:26 +0100 Subject: [PATCH] survey: Include LPKF LDS citation --- chapter-hsms/chapter.tex | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/chapter-hsms/chapter.tex b/chapter-hsms/chapter.tex index 5dfb4c3..a00efb5 100644 --- a/chapter-hsms/chapter.tex +++ b/chapter-hsms/chapter.tex @@ -617,16 +617,16 @@ inks have high resistance, and can be used to create embedded resistors. The cir Figure~\ref{hsm_fig_materials_silver_ink} contains a tamper sensing mesh on a lower layer, and a keypad matrix with carbon contacts on its surface. -Figure~\ref{hsm_fig_materials_gold_lds} shows part of a mesh and a contact created using Laser Direct Structuring, a -technique combining selective activation of a plastic surface using a scanning laser and electroless gold plating. Where -in electroplating electrical current is used to deposit metal atoms on a surface, in electroless plating a series of -chemical reactions is used. Electroplating requires all traces to be electrically connected to form a single electrode, -while electroless plating can be used on the finished circuit. Laser Direct Structuring allows patterning complex -surfaces with fine structures made from metal deposited in a thin layer. In Figure~\ref{hsm_fig_materials_gold_lds}, it -is visible how the trace was created using three parallel passes by the laser. The micrograph also shows the rather -coarse edge structure created by LDS, which is caused by the rough surface left after pulsed laser ablation. The uneven, -thin layer of metallization created by LDS results in mechanically fragile contacts that must be contacted using a soft -material, usually an elastomeric connector. +Figure~\ref{hsm_fig_materials_gold_lds} shows part of a mesh and a contact created using Laser Direct Structuring, an +industrial technique combining selective activation of a plastic surface using a scanning laser and electroless gold +plating~\cite{lpkflaser&electronicsagLPKFLDSLaser2014}. Where in electroplating electrical current is used to deposit +metal atoms on a surface, in electroless plating a series of chemical reactions is used. Electroplating requires all +traces to be electrically connected to form a single electrode, while electroless plating can be used on the finished +circuit. Laser Direct Structuring allows patterning complex surfaces with fine structures made from metal deposited in a +thin layer. In Figure~\ref{hsm_fig_materials_gold_lds}, it is visible how the trace was created using three parallel +passes by the laser. The micrograph also shows the rather coarse edge structure created by LDS, which is caused by the +rough surface left after pulsed laser ablation. The uneven, thin layer of metallization created by LDS results in +mechanically fragile contacts that must be contacted using a soft material, usually an elastomeric connector. \subsubsection{Connection methods}