Wafer-dicing process

Details Wafer-dicing process Wafer-dicing process

2000-07-10

2001-11-20

Fourson, George (Department: 2823)

Semiconductor device manufacturing: process

Packaging or treatment of packaged semiconductor

Making plural separate devices

C438S117000, C438S464000

Reexamination Certificate

active

06319754

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a wafer dicing process, more particularly to a wafer dicing process employing a wafer mounting sheet that has multiple layers of different mediums with different bonding strengths.
2. Description of the Related Art
FIGS. 1 and 2
illustrate a conventional wafer-dicing process for cutting a wafer
101
into dice
106
. The wafer-dicing process includes the steps of: attaching the wafer
101
to a wafer mounting sheet
100
which includes a bonding adhesive layer
102
adhered to the wafer
101
on one side and adhered to a releasable film
103
on the other side; peeling off the releasable film
103
from the bonding adhesive layer
102
; attaching the bonding adhesive layer
102
of the assembly of the wafer
101
and wafer mounting sheet
100
to a resilient wafer carrier sheet
104
, such as a blue tape; cutting the wafer
101
on the carrier sheet
104
with a cutter
105
to form dice
106
and a plurality of bonding adhesive layer sections
110
that are respectively adhered to the dice
106
; sucking one of the dice
106
with a pick-up unit
108
, such as a vacuum pad, and pushing upwardly the carrier sheet
104
with a pointed pin
107
to deform plastically the carrier sheet
104
so as to permit removal of the respective one of the bonding adhesive layer sections
110
from the carrier sheet
104
; and through the use of the pick-up unit
108
, moving and mounting said one of the dice
106
, which has the respective one of the bonding adhesive layer sections
110
adhered thereto, to a die mounting substrate
109
in preparation for a subsequent operating step, such as a wire bonding step.
The aforesaid process is disadvantageous in that the bonding adhesive layer
102
tends to become contaminated during the aforementioned processing steps, thereby affecting adversely the bonding a strength of the bonding adhesive layer
102
upon adhering to the die mounting substrate
109
. Moreover, in order to adhere the die
106
to the die mounting substrate
109
securely, the bonding strength of the bonding adhesive layer
102
is relatively strong to provide a sufficient bonding strength. However, such bonding strength tends to generate a bonding force between the bonding adhesive layer
102
and the carrier sheet
104
that is too strong to permit separation of the bonding adhesive layer
102
from the carrier sheet
104
during the sucking and picking operation, thereby causing deformation of the die
106
due to the pushing of the pointed pin
107
(see FIG.
3
). There is also a possibility that a portion of the bonding adhesive layer
102
will remain on the carrier sheet
104
, thereby further weakening the bonding quality between he bonding adhesive layer
102
and the die mounting substrate
109
.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a wafer-dicing process that is capable of overcoming the aforementioned problems.
According to the present invention, a wafer-dicing process for cutting a wafer into dice, comprises the steps of: a) attaching the wafer to a wafer mounting sheet which includes a bonding adhesive layer adhered to the wafer, a releasable film layer adhered to the bonding adhesive layer, a resilient substrate layer attached to the releasable film layer, and a light-curable adhesive layer adhered to the resilient substrate layer, the bonding adhesive layer, the releasable film layer, the resilient substrate layer, and the light-curable adhesive layer being stacked one above the other; b) laying assembly of the wafer and the wafer mounting sheet on a transparent resilient wafer carrier sheet, and exposing assembly of the wafer, the wafer mounting sheet and the resilient wafer carrier sheet to cure the light-curable adhesive layer such that the light-curable adhesive layer adheres to the resilient wafer carrier sheet, wherein bonding strength between the releasable film layer and the bonding adhesive layer is weaker than those between the wafer and the bonding adhesive layer, the releasable film layer and the resilient substrate layer, the resilient substrate layer and the cured light-curable adhesive layer, and the cured light-curable adhesive layer and the carrier sheet; c) cutting the wafer on the carrier attached to the bare dice; d) sucking one of the dice with a pick-up unit and pushing upwardly the carrier sheet with a pointed pin to deform plastically the carrier sheet, the cured light-curable adhesive layer, the resilient substrate layer, and the releasable film layer of the respective one of the wafer mounting sheet sections so as to permit removal of the bonding adhesive layer of the respective one of the wafer mounting sheet sections, which is adhered to said one of the dice, from the releasable film layer of the respective one of the wafer mounting sheet sections; and e) through use of the pick-up unit, moving and mounting said one of the dice, which has the bonding adhesive layer of the respective one of the wafer mounting sheet sections adhered thereto, to a die mounting substrate.


REFERENCES:
patent: 6042922 (2000-03-01), Senno et al.
patent: 6204092 (1999-04-01), Freund et al.
patent: 06021219 (1994-01-01), None
patent: 11017158-A (1999-01-01), None

Affiliated with

Also associated with

Rating

Wafer-dicing process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Wafer-dicing process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wafer-dicing process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2579622