In this lesson

Sooner or later you want to ask about part of the data: one split, one bin, one region of a wafer. This lesson shows the two tools for that, filters and selections, and what the right-click menu does with them.

• Keep only the wafers and dies that meet your conditions
• Chart and tabulate any selection, bin or wafer
• Know what each entry of the right-click menu opens

Filter…

Filter… lets you look at only the data you care about. The button is at the right of the toolbar, beside Maps and Insights. It keeps only the wafers and dies that meet conditions you set, in the gallery, on a single map and on every Insights tab.

Suggestions in the JSON

• Suggest, or typing a comma or a brace, offers the keys, the lot's fields and tests, and the values a field takes
• The line under the text says how many wafers and dies the filter keeps, and follows what you type
• While the text cannot be read, Apply is held and the window says why

Wafer or die

A condition works on one of two levels, and they behave differently.

• A wafer condition keeps whole wafers; the rest leave the gallery
• A die condition keeps matching dies; the rest are drawn faded
• The Summary panel and findings are worked out again over what is kept

Applied

With the filter applied, four cards remain (W04, W11, W18 and W24), and the legend and yield describe only those wafers.

The filter line

A line above the view always states the filter and what it keeps. Its checkbox switches the filter off and on without losing it. 1 Edit… reopens the window; 2 Remove deletes the filter.

Insights follows

There is one filter for everything you are looking at, so Insights shows the same four wafers, and its charts and the Group by control work on what is kept. You never have to set the same filter twice.

The filter stays

tsmap remembers the filter, and whether it is on, for the next lot and the next start. The line above the view always states it, so a carried-over filter is never applied unseen. Remove forgets it.

Select dies

A filter is for the whole session. A selection is for a quick question. Drag a box on a map: the selected dies keep their colour and the rest fade, with an outline round them. Ctrl or Cmd + click adds or removes a die; Esc clears.

Value histogram

Value histogram shows how one test is distributed over just those dies, which tells you whether the selected region reads differently from the rest. The title and the line above state the population, so it cannot be mistaken for the whole wafer. The PAT lines are outlier limits worked out per wafer (lesson 05).

Process capability

Process capability shows each test's spread over the selected dies only, drawn against its limits and ordered worst Ppk first. Lesson 06 explains Ppk and charts the whole lot's capability, for comparison.

Test statistics

Test statistics shows the Test Values and Functional Tests tables, over the same dies.

Dies

The Dies table has one row per selected die, with its position, bins and every test value. Export CSV writes the table to a file and Copy puts it on the clipboard. Choose Wide (a column per test) or Long (a row per die and test) first.

A snapshot of its dies

These charts are snapshots, so they do not change under you.

• Each chart states its population, so it is never taken for the whole lot
• A chart already open keeps its dies when the selection changes
• An entry that cannot be drawn stays, greyed, with the reason

What you right-click decides the population

The menu is always the same. What changes is which dies it covers.

A bin

To study one failure mode across the whole lot, right-click a bin in the gallery's legend. The menu opens on that bin's dies on every wafer of the lot. It leaves your selection as it is; the legend only changes what is drawn.

A whole wafer

Each card's Charts and tables button, the small chart icon in its toolbar, opens the same menu for that wafer.

Recap

• Filter… keeps wafers and dies by condition, in every view
• Select dies, then right-click for charts and tables of just those dies
• A bin, a wafer or a finding each opens the same menu on its own dies

Next, make new tests of your own, and read a run of tests as a curve.

More in the wafer map guide