00198371-01_UM_SWS-EN - 第20页
1 Introduction User manual SIPLACE Wafer System (SWS) 1.2 Description of functions Edition 04/2018 20 1.2.3.2 Die att ach process The optional die atta ch unit is needed for the die att ach process. In this method, the d…
User manual SIPLACE Wafer System (SWS) 1 Introduction
Edition 04/2018 1.2 Description of functions
19
1.2.3.1 Flip chip process
The flip chip process is the standard method for SWS. The die is rotated by 180° before placement
(face down placement).
1
Fig. 1.2 - 2 Flip chip process (basic principle)
The flip chip process steps are:
– Step 1: Die release
– Step 2: The die is rotated by 180° and is passed on to the placement head. Parallel to this,
the next die is taken up by the second nozzle of the flip unit.
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).
1
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