Die Attach Scenario#

Overview#

This modeling guide aims to propose a base model approach for the Die Attach process. This guide includes a detailed Equipment Integration use case, starting from material preparation and continuing until lot completion.

Business Context#

The Die Attach or Die Bonding process is a fundamental step in the Backend portion of the Semiconductor Industry. It is one of the earliest assembly operations, where the silicon die is attached to a substrate or package so that the device can later be wire bonded, encapsulated, and integrated into electronics systems. In a nutshell, this step transforms a bare silicon die into a usable component.

The quality of Die Attach process directly affects:

• Electrical performance (thermal path, conductivity)
• Mechanical stability (strength of adhesion)
• Heat dissipation (critical for high-power devices)
• Device reliability (poor attach can lead to early failures)

MES Modeling#

This modeling section includes the definition of the base model, validations, material tracking, and interactions between MES, equipment, and operator during this process.

The Die Bonder equipment can be modeled as the main equipment Resource, with three Load Ports to support:

• Strip/panel input
• Strip/panel output
• Wafer cassette input

Depending on the consumable tracking needs, a Feeder sub-resource can be added for the epoxy consumable, and optionally, a durable positions can be setup to assure usage of the correct tooling parts for:

• Epoxy dispensing kit
• Wafer table
• Die ejector kit
• Pickup tool
• Warpage downholder

In terms of Material structure, it is expected that there is:

• A lot material of strips/panels tracking-in and out of the tool, containing multiple submaterials
  • Submaterials representing each strip/panel contained in a magazine Container.
• A wafer cassette Container providing source wafers for die consumption
• Particular dies are not tracked as Materials in MES, but can be tracked in wafer/strip maps instead.

The below image summarizes a standard Die Attach resource with the described auxiliaries. The diagram doesn't aim to be an exact replica of this process scenario, as it varies according to each shopfloor reality.

Modern Die Attach modeling often benefits from incorporating substrate mapping, especially when dies are not uniform, when bad dies must be skipped, or when traceability requirements are high. SEMI E142 and G85 standards provide the industry standard for how substrate maps are reported, stored, and exchanged between equipment and MES

For Die Attach process, the incoming wafers and strips may already contain a maps marking good, bad, or "special-purpose" dies. The Die Bonder uses this map to navigate, pick good dies, and record placement outcomes. MES can store these E142 map files to:

• Validate wafer compatibility
• Track die‑level consumption
• Ensure all die placements align with quality and binning rules

Preparing the Die Bonder#

1. The user dispatches a strip lot to the Die Bonder and manually docks in MES an empty container in the output LoadPort, for later receiving the completed strips. If the machine is able to read magazine IDs, then this step can be done automatically via Connect IoT when physically docking the empty magazine in the LoadPort.
2. The docking & dispatching event, trigger MES to perform the following validations:
   • Machine is allowed to process for this product
   • Machine is in conditions to start processing (e.g. state validation)
   • The dispatched lot is eligible for the operation (there is no constraint for time-windows)
   • Correct durables and raw materials are attached and valid in terms of expiration times
   • There is a docked and empty magazine in the output Load Port

Loading Wafer Cassette#

1. User docks the wafer cassette into the correspondent Load Port (if the machine cannot read cassette ID).
2. IoT may trigger SlotMap Verification, depending on the tool capabilities.
3. MES is expected to validate:
   • Wafer lot matches the strip Product BOM
   • Wafer belongs to same Production Order as strip lot (if pre-reserved)
   • Wafer lot is valid for consumption in terms of time window.
   • Equipment requests IoT the WaferMap which is sent to the tool from MES side

Handling Magazines and Strip Lot Loading#

1. User physically places the input strip lot container in the respective LoadPort.
2. User Tracks in the strip lot.
3. IoT Selects/Downloads the correct recipe to the Die Bonder tool in MES and signals the machine to start Job.
4. Machine picks up the magazine and reads its ID.
5. MES validates if the magazine ID read belongs to the strip lot that was tracked-in
6. Machine loads the first strip into the conveyor and reads that strip ID.
7. MES validates the strip ID belongs to the strip lot.
8. MES repeats previous strip material validations for each strip loaded and if:
   • Raw material (Epoxy) is not expired
   • The correct durables and consumables are still attached

Strip Start#

1. Machine requests the strip Map which is provided by MES
2. MES tracks in the strip submaterial (if submaterial tracking enabled).

Wafer Handling#

1. Machine loads the first wafer and proceeds to reads the wafer frame ID.
2. Machine requests the Wafer Map to MES
3. MES validates if the wafer belongs to the wafer lot docked earlier and provides the Wafer Map.

Strip Processing#

1. Machine starts processing the strip that was previously tracked-in.
2. Machine issues alarms if conditions arise.
3. Machine performs measurements (e.g. die shift, tilt, BLT, etc.).
4. MES collects alarms and triggers workflows for pre-defined cases (e.g., epoxy syringe exchange).
5. MES collects the measurements, updates SPC charts if defined, and triggers exceptions if needed.
6. MES stores relevant data in the Data Platform.

Strip Completion#

1. Processing of the strip is completed.
2. Machine provides the updated strip BinCode Map and Transfer Map.
3. MES updates all strip-level maps (Substrate Map, BinCode Map, Transfer Map).
4. MES consumes dies from wafer according to Transfer Map.
5. MES records losses automatically on the strip, using bin code map.
6. MES assembles unit traceability data (DeviceID Map+ Transfer Map) and sends it to the Data Platform.

Wafer Completion#

1. Wafer is finished and unloaded from the Machine
2. Machine provides the updated Wafer BinCodeMap.
3. MES updates Wafer Substrate Map.
4. Loss recording on the wafer is held until lot end to avoid conflicts related to strip consumption

This process repeats for every strip and every wafer until the strip lot ends.

Lot Completion#

1. The entire strip lot is completed.
2. Machine provides the updated maps until the last strip.
3. MES updates all strip maps, consumption, losses, traceability.
4. MES tracks out the lot and updates wafer-level losses (synchronize quantities) using all wafer maps.