Patent Application
20080265462
The present invention relates to an apparatus and a method for panel/wafer molding, and more particularly to a simple apparatus and a method for panel/wafer molding.
In the field of semiconductor devices, the device density is increased and the device dimension is reduced continuously. The demand for the packaging or interconnecting techniques for such high density devices is also increased.
Conventional package technologies have to divide a dice on a wafer into respective one and then packaging the die respectively, therefore, these techniques are time consuming for manufacturing process. Since the chip packaging technique is highly influenced by the development of integrated circuits, therefore, as the size of electronics has become demanding, so does the package technique. For the reasons mentioned above, the trend of package technique is toward ball grid array (BGA), flip chip (FC-BGA), chip scale package (CSP), Wafer level package (WLP) today. “Wafer level package” is a kind of technology that the entire packaging as well as other processing steps are carried out before singulating into single die. By wafer level packaging technology, we can produce die with extremely small dimensions and good electrical properties.
Though the advantages of WLP technique mentioned above, some issues still exist influencing the acceptance of WLP technique. Traditionally panel/wafer molding process requires a molding machine composing upper and lower tools and forming molding layer by injection mold method, wherein the material for molding layer is epoxy type material. The traditional way for panel/wafer molding is expensive and the other shortcomings of these tools comprise: these tools needing long time to assemble, the wafer or panel is easily to be damaged during molding process, warp often happens during process and special tapes or tools are required for protecting the wafer and panel.
Therefore, it is desirable to develop a method and an apparatus for cheap, easy molding without doing damage to a wafer/panel.
One advantage of the present invention is providing a simple universal panel/wafer molding apparatus.
One advantage of the present invention is providing a simple panel/wafer molding process.
One advantage of the present invention is providing a simple panel/wafer molding apparatus and method for forming a round or rectangular type panel.
One advantage of the present invention is providing a simple panel/wafer molding apparatus and method for separating the molded panel.
Another advantage of the present invention is that the shape, for example thickness and flatness, of the molded panel is adjustable and controllable.
Another advantage of the present invention is that the molding process does no harm to the chip active surface.
Another advantage of the present invention is that no warp happens during the process.
Another advantage of the present invention is that the molding material can be liquid compound, liquid epoxy, resin, silicon rubber with or without filter.
The present invention provides an apparatus for panel/wafer molding, comprising: a base with a first separation layer applied thereon for placing dice, an upper molding base with a second separation layer on the bottom surface; a vacuum chamber; a microprocessor for controlling the molding process. The apparatus further comprises a component for mechanical and/or optical alignment and a component for curing. The upper molding base is round or rectangular. The microprocessor is programmed for controlling thickness and flatness of the molding layer.
The present invention provides a method for panel/wafer molding, comprising: providing a base with a first separation layer for placing dice; applying a molding layer covering the dice and filling into the space between the die; bonding an upper molding base, which is rectangular or round, on the upper surface of the molding layer by vacuum panel bonding, shaping the molding layer; curing the molding material for forming a panel; separating the panel from the first separation layer; separating the panel from the second separating layer of the upper base panel. The molding layer is formed by vacuum printing and made by liquid compound, liquid epoxy, resin, silicon rubber with or without filter; moreover, the thickness and flatness of the molding layer is controlled by program. The vacuum bonding is performed in vacuum chamber, controlled by mechanical and/or optical alignment process and the magnitude and time of force applied is controlled by program.
The invention will now be described in greater detail with preferred embodiments of the invention and illustrations attached. Nevertheless, it should be recognized that the preferred embodiments of the invention is only for illustrating. Besides the preferred embodiment mentioned here, present invention can be practiced in a wide range of other embodiments besides those explicitly described, and the scope of the present invention is expressly not limited expect as specified in the accompanying claims.
The present invention discloses a method for panel/wafer molding. As shown in
Turning to
The vacuum panel bonding machine 710 of the present invention is used for bonding an upper molding base on the upper surface of the molding layer. The vacuum panel bonding machine 710 comprises an upper molding base and a vacuum chamber 7105, and a microprocessor 7110. A second separation layer is formed at the bottom of the upper molding base. The vacuum panel bonding machine 710 is equipped with a vacuum chamber for performing vacuum panel bonding. In another preferred embodiment of the present invention, the vacuum panel bonding machine 710 performs thickness control, wherein the thickness control is controlled by program to control the flat and thickness of the molding layer. In another preferred embodiment of the present invention, the thickness and flatness of the molding layer is controlled by the magnitude and time of force applied. In another preferred embodiment of the present invention, the vacuum panel bonding machine align upper molding layer with molding layer; wherein the alignment is controlled by an unit performing mechanical and/or optical alignment.
The curing unit 720 of the apparatus for panel/wafer molding performs curing process for forming a panel composed of an upper molding base, molding layer and die. The cleaning unit 730 of the apparatus for panel/wafer molding performs removing process for shaping the panel into round or rectangular shape or/and for cleaning the surface of the panel, for example, by solution. In another preferred embodiment of the present invention, the separating unit 740 performs separating process, for example, preceded by mechanical force, for separating the panel from the second separation layer.
Although preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that the present invention should not be limited to the described preferred embodiments. Rather, various changes and modifications can be made within the spirit and scope of the present invention, as defined by the following claims.
