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--- wirebonding [2025/12/11 12:29] – created gus
+++ wirebonding [2026/02/18 08:14] (current) – gus
@@ Line 4: / Line 4: @@
 The wirebonder manual:{{7476E Manual.pdf}}
+As of January 2026, West Bond is no longer operating. Matt Ritchie (who did a service visit Dec '25) started a company and is doing service work on the tools: [[https://www.norcaltechsales.com/|NorCal Technical Sales]].
+====== Introduction to Wirebonding ======
+This video give a good introduction:
+https://www.youtube.com/watch?v=mvZ1dJuvenw
 ====== Wedge bonding Theory ======
 Wedge bonding relies on the application of ultrasonic power and force to bond the wire (bonding wire) to a metal pad (bonding pad). The careful application of both force and ultrasonic power deform the wire and diffuse the wire metal into the pad without weakening the wire too much. The strength of the wire after bonding is shown below as a function of deformation from ultrasonic energy and force applied.
-{{wirebonding_optimization.png}}
+{{wirebonding_optimization.png?700}}
 Outside the optimal range,
 Foot lift: the bond pulls off the pad, meaning the metals didn't have intimate contact.
-{{wirebonding_foot_lift.png}}
+{{wirebonding_foot_lift.png?400}}
 Weak bond: the wire was deformed too much by the bond tool.
-{{wirebonding_weak_bond.png}}
+{{wirebonding_weak_bond.png?400}}
 The surface quality is also important. While the deformation needs to be managed, clean and properly adhered bond pads are important to successful bonding.
@@ Line 56: / Line 68: @@
-The wire should be deformed no more than 150% of the original width. See below:
+The wire should be deformed about 150% of the original width. See below:
-{{wirebonding_top_view.png}}
-((maybe I need a new diagram that doesn't cut the BL2))
+{{wirebonding_deformation.jpg?400}}
 To tune this, do the following:
@@ Line 89: / Line 100: @@
 The wire should come out of the bond tool straight towards you when everything is aligned.
+====== Chip Packages ======
+For chips going into the Cryostat in 308, they must be wirebonded to a [[https://www.spectrum-semi.com/products/sidebraze|Dual In-Line Package (DIP)]]. There are a few steps to prepare:
+  - Cut the chip to size. You can use a razorblade as a shield for the sensitive part of the device while you scribe your substrate.
+  - Clean your package if it was previously used. Cleaning silver paint is a pain, so it can be beneficial to but new packages if we can afford it.
+  - Tack your chip (and maybe a filler chip, see below) to the package using silver paint. The back of a wooden Q-tip is great as it will leave just enough paint to hold the chip, but not make a mess.
+Once dried, you can wirebond.
+==== Filler chips ====
+If you want to focus a laser on your chip while in the cryostat, you'll need to ensure it is tall enough that it can sit in the focal plane of the objective you're using. To help, you can raise your chip up by tacking a "filler chip" in and then tacking your "device" chip on top of that.
 ====== Misc. ======
@@ Line 96: / Line 118: @@
   * The drop before clamp parameter is better left off. When on, when lowering the tool after the first bond, the clamp will engage. This tension can be problematic.
   * The loop height parameter only changes when the tool beeps when raising the bond head. It has no mechanical impact on the bond.