BTXF Fab Test and Assembly

BTXF Enabling a Reconstituted Wafer-to-Assembly Workflow for Advanced Semiconductor Devices

Customer Challenge

Existing handling methods addressed portions of the workflow but not the complete process:

• Dicing tape provided support during singulation but was not optimized for repeated pick,
  re-pick, and selective die removal.
• Pocketed carriers required device-specific geometries that limited flexibility as product
  designs evolved.
• Multiple carrier transitions introduced additional handling steps and increased
  opportunities for positioning errors, device damage, and process variation.
• Automation systems required consistent die presentation throughout testing and assembly
  preparation.

As advanced packaging architectures became more complex, the customer needed a
handling strategy that could maintain die organization from temporary wafer reconstruction
through assembly preparation while reducing process complexity.

Solution

Gel-Pak worked with the customer to implement a BTXF-based handling platform that supported the entire process flow rather than individual process steps. Singulated devices were first placed onto a BTXF Wafer Carrier, creating a reconstituted wafer format suitable for inspection, testing, and classification. The textured elastomer surface securely retained the die while maintaining accessibility for automated handling equipment. The BTXF textured surface is designed to hold components while allowing easy removal when required.

During testing, devices remained organized and identifiable while engineers evaluated performance and classified components.
Following test:

• Failed devices could be selectively removed.
• Known Good Die (KGD) remained accessible for automated pick-and-place operations.
• Devices could be re-picked or transferred without disrupting the remaining population.
• Die organization and orientation were maintained throughout the process.

Once test and binning were complete, the KGD population was transferred directly into BTXF
JEDEC trays for movement into assembly operations.

The result was a common retention platform spanning both reconstituted wafer handling and assembly preparation, reducing the need for multiple handling technologies across the workflow. BTXF supports deployment in wafer formats, tray formats, JEDEC configurations, and custom substrates, allowing the customer to implement a consistent handling architecture throughout the process.

Results

Improved Process Continuity
Instead of transitioning between multiple carrier technologies throughout the workflow, the customer utilized a common BTXF handling platform from reconstituted wafer test through KGD transfer and assembly preparation.

Greater Flexibility During Test and Binning
Engineers maintained die-level access throughout the process, enabling selective removal, re- pick operations, and sorting activities without disrupting neighboring devices.

Reduced Dependence on Custom Carrier Designs
Because retention was provided by the textured film surface rather than device-specific pockets, the solution supported changing device geometries without creating the same level of tooling dependence associated with conventional pocketed carriers.

Improved Automation Readiness
Consistent device presentation supported automated inspection, testing, and pick-and-place operations. Maintaining die position throughout the process reduced variability that can impact automated handling systems.

Better Support for Known Good Die Strategies
The customer gained a handling approach capable of preserving tested devices through transportation, staging, and assembly preparation without introducing unnecessary handling transitions.

Why BTXF Was Selected

The customer’s selection criteria extended beyond simple device transport. The required solution needed to:

• Support temporary wafer reconstruction
• Present devices for test and inspection
• Allow selective die removal and re-pick
• Maintain organization during KGD processing
• Transition smoothly into assembly workflows
• Support automation requirements
• Reduce dependence on custom pocket geometries

BTXF met these requirements by combining secure temporary retention with controlled release capability in a format that could be deployed throughout multiple stages of the manufacturing process. The technology was developed as a universal handling platform capable of supporting bare die and leadless packaged components across a range of carrier configurations.

Key Takeaway

For advanced semiconductor manufacturers implementing shift-left testing, known good die
strategies, and advanced packaging workflows, device handling is no longer simply a transportation problem.
Result: By using BTXF as a common handling platform from reconstituted wafer test through assembly preparation, manufacturers can maintain die organization, preserve accessibility, and support automation while reducing the complexity associated with managing multiple carrier technologies throughout the process.