Equation 4 · Part 2 · Chiplets and Advanced Packaging in Practice: An Advanced Technical Guide
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→Article meaning
The passage around this formula
which is a first-order model — it assumes bonding introduces no additional defects and that die yields are independent, both of which are simplifications addressed separately below. Even under this optimistic assumption, four chiplets each yielding 95% compose to roughly 81% assembly yield, and a twenty-die stack at the same per-die yield falls to roughly 35% — the industry’s own framing of why an unscreened stack becomes uneconomical fast as die count rises [ 4 ] . The entire purpose of KGD testing is to push each as close to 1 as pre-bond screening allows, since the model shows the product is unforgiving of even small per-die shortfalls once several dies are chained together.
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.