00198371-01_UM_SWS-EN.pdf - 第21页
User manual SIPLACE Wafer System (SWS) 1 Introduction Edition 04/2018 1.2 Description of functions 21 1.2.3.3 Die recognition and positioning The wafers are fixed to the wa fer foil with a specific position and angular t…
1 Introduction User manual SIPLACE Wafer System (SWS)
1.2 Description of functions Edition 04/2018
20
1.2.3.2 Die attach process
The optional die attach unit is needed for the die attach process.
In this method, the die is placed in the same bottom/top orientation as it was on the wafer foil
("face-up" placement).
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Fig. 1.2 - 3 Die attach process steps (basic principle)
The die attach process steps are:
– Step 1: Die release
– Step 2: The die is rotated by approx. 130°and transferred to the die attach unit.
– Step 3: The die attach unit rotates the die into the pickup position and transfers it to the place-
ment head. Parallel to this, the next die is picked up by the flip unit.
User manual SIPLACE Wafer System (SWS) 1 Introduction
Edition 04/2018 1.2 Description of functions
21
1.2.3.3 Die recognition and positioning
The wafers are fixed to the wafer foil with a specific position and angular tolerance.
It is therefore not possible to place the die reliably in the center of the ejector unit without recog-
nition and correction. This is particularly important for small dies, in order to ensure reliable ejec-
tion.
Furthermore, you may need to process only a selection of dies. A selection can be made by mark-
ing with an ink spot and/or by using a wafer map file for the relevant wafer.
The following components are used for this process step:
– 2 axes wafer table for positioning
– Wafer camera system for the die and for optional ink spot recognition
– Barcode scanner for wafer identification (optional)
1.2.3.4 Ejection process
Once the die has been centered using the ejector system, it can be released from the wafer foil
using needles and transferred to the flip unit. Piercing or non-piercing needles are used for this.
While the needles release the die from the foil, the wafer foil is moved towards the ejection system
by means of suction.
The following components are used for this process step:
– Ejector unit
Fig. 1.2 - 4 Ejection process - non-piercing (basic principle)
Ejection needle
Vacuum cap
Ejection system - non-piercing needles
Active component - ready for pickup
Wafer foil
The wafer foil is sucked up by vacuum
at the vacuum cap
1 Introduction User manual SIPLACE Wafer System (SWS)
1.2 Description of functions Edition 04/2018
22
Fig. 1.2 - 5 Ejection process - piercing (basic principle)
1.2.3.5 Pickup process
During the pickup process, the die is transferred to the tool or to the nozzle of the flip unit. The flip
unit transfers the die on it either to the placement head (flip chip process) or to the die attach unit
(die attach process).
The die attach unit rotates the die again and then presents it to the placement head.
The following equipment is required for this step:
Flip unit
Die attach unit (optional)
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Ejection needle
Vacuum cap
Ejection system - piercing needles
Active component - ready for pickup
Wafer foil
The wafer foil is sucked up by vacuum
at the vacuum cap