Patent Application
20130161867
The present invention is related to a molding apparatus and a method for molding.
In the technical field of molding processes and molding apparatuses an increasing demand exists for fabricating products with precisely defined shapes or dimensions. This applies in principle for all areas in which products as such are formed by mold materials or are embedded or encapsulated by mold materials. As one example, in the field of electronic devices semiconductor chips or dies are mostly encapsulated in a mold material in such a way that contact pads on a main surface of the semiconductor chips are connected with external contact elements on a main surface of the encapsulating material. One example is the so-called molded array package (MAP) which includes encapsulating any sort of carrier or interposer on one side, the carrier or interposer being made of, for example, a leadframe, a laminate, a Capton tape or a ceramic material. Another example is the so-called Embedded Wafer Level Ball Grid Array (eWLB) technology which was developed in particular to provide a wafer level packaging solution for semiconductor devices requiring a higher integration level and a greater number of external contacts. In particular, with respect to semiconductor chip package devices it becomes increasingly important to fabricate a semiconductor chip package device with a very small overall thickness which can be adjusted by the fabrication process in a precise manner within a small tolerance range. Such a demand for very thin semiconductor packages with a precisely defined thickness especially applies for chip card applications, but also for mobile communication chips and power chips.
The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of the disclosure. Other variations and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the figures being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
The aspects and embodiments are now described with reference to the drawings, wherein like reference numerals are generally utilized to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects of the disclosure. It may be evident, however, to one skilled in the art that one or more aspects of the embodiments may be practiced with a lesser degree of the specific details. In other instances, known structures and elements are shown in schematic form in order to facilitate describing one or more aspects of the disclosure. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the disclosure. It should be noted further that the drawings are not to scale or not necessarily to scale.
In addition, features or aspects disclosed may be combined with one or more other features or aspects of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “include,” “have,” “with” or other variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprise.” The terms “coupled” and “connected,” along with derivatives may be used. It should be understood that these terms may be used to indicate that two elements co-operate or interact with each other regardless of whether they are in direct physical or electrical contact, or not in direct contact with each other. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
In the following disclosure a molding apparatus or a method for molding are described both of which can be used for fabricating any sort of product or to encapsulate any sort of pre-fabricated product like, for example, a semiconductor chip. For that purpose a mold material or encapsulant material will be utilized. The encapsulant material can be, for example, any electrically insulating material like, for example, any kind of plastic mold material, any kind of epoxy material, or any kind of resin material with or without any kind of filler materials. The encapsulant material can also be any sort of electrically or thermally conducting material, sinter material, laminate material, nano-paste material, i.e., any material containing microscopic or nanoscopic particles, in particular conducting particles, or any material containing glass fibers or carbon fibers for use in, for example, the car industry. The encapsulant material can also be a ceramic paste, i.e., a material containing any sort of ceramic polymer or filler or ceramic particles, or hybrid epoxy/ceramic material.
In particular, when fabricating the semiconductor chips and the packaging of the semiconductor dies with the encapsulant material, fan-out embedded dies can be fabricated. The semiconductor chips can be arranged on substrates of any sort of shape or material like, for example, on square-shaped or circle-shaped substrates, on leadframe-based substrates, ceramic-based substrates, interposer substrates, laminate substrates, and flexible substrates. The fan-out embedded dies can be arranged in an array having the form, e.g., of a wafer and is therefore often called a “re-configured wafer.” However, it should be appreciated that the fan-out embedded die array is not limited to the form and shape of a wafer but can have any size and shape and any suitable array of semiconductor chips embedded therein. This technology is called extended wafer level packaging technology. It can also be defined that within this application the term “wafer” applies not only to circular shaped substrates but also to square-shaped substrates or substrates of any other shape. In the following the semiconductor chips packaged with the encapsulant material will be designated with the general term “semiconductor chip panel.”
In the claims and in the following description different examples of a method of fabricating a semiconductor device are described as a particular sequence of processes or measures, in particular in the flow diagrams. It is to be noted that the disclosure should not be necessarily limited to the particular sequence described. Particular ones or all of the different processes or measures can also be conducted simultaneously or in any other useful and appropriate sequence.
Aspects and embodiments of a molding apparatus and a method for molding can be used for fabricating products or fabricating an encapsulation layer for embedding products as, for example, a plurality of semiconductor chips. To this end, the individual semiconductor chips are placed on a carrier and a mold material can, for example, be dispensed onto a central portion of the array of semiconductor chips. Thereafter the carrier can then be placed in a molding apparatus and within the molding apparatus the dispensed mold material can be molded and cured to obtain a semiconductor chip encapsulated layer panel. The semiconductor chip panel can then be taken out of the molding apparatus for further processing and finally singulating the panel into a plurality of semiconductor chip package devices.
Referring to
Molding apparatus 10 may comprise an end position which defines the main cavity 1 and the buffer cavity 2 and in which end position the entire cavity comprising the main cavity 1 and the buffer cavity 2 is dense to the outside so that no mold material can flow out and only excess mold material can flow from the main cavity 1 to the buffer cavity 2. In the schematic drawing of
The end position as described before is not necessarily defined by a mechanical stop such as a mechanical stop of a clamp ring of an upper tool reaching an upper surface of a lower tool. The end position can also be defined by an exact motor control of a first tool moving downwards a second tool by software control of the motor or motors driving the first tool. For example, it can be controlled that the downward movement of the first upper tool comes to a stop when the distance between the first and second tool is exactly 150 μm, for example, so clear height of the main cavity is precisely defined in this way. Of course also in this case it must be guaranteed that in the end position the entire cavity, i.e., main cavity and buffer cavity, is dense to the outside. An end position as described before can also be called a machine-defined or software-defined or software-controlled end position.
Buffer cavity 2 may comprise a variable spatial volume. Buffer cavity 2 is shown to have a number of boundary walls. One of these boundary walls can, for example, be configured as a movable or displaceable boundary wall so that the volume of the buffer cavity 2 can be varied. In the schematic drawing of
A passage 3 can be formed between the main cavity 1 and the buffer cavity 2 for excess mold material to flow from the main cavity 1 to the buffer cavity 2. The passage 3 can be situated such that it comprises a boundary wall, which is in one and the same plane as that of a boundary wall of the main cavity 1, and another opposing boundary wall, which is that of a wall separating the main cavity 1 from the buffer cavity 2. The distance between these opposing boundary walls of the passage 3 can, for example, be less than 1000 μm, or less than 500 μm, or even less than 100 μm, in particular 10 μm to 50 μm, more particular 20 μm to 40 μm.
It is also possible that two or more buffer cavities are connected with the main cavity. The buffer cavities can either have identical construction, form and spatial volume or alternatively can also have different construction, form or spatial volume for any reason.
Main cavity 1 can have a square shape or a circular shape in a top view, in particular for housing therein a carrier panel having also square shape or circular shape like, for example, a re-configured circular or square shaped “wafer” comprising a plurality of semiconductor devices for embedded wafer level packaging. According to an embodiment thereof, the molding apparatus 10 can then have two or more buffer cavities 2 connected at lateral positions to the main cavity 1. The buffer cavities can then be arranged at pre-defined lateral positions of the main cavity, in particular at regularly spaced angular positions. A specific embodiment thereof will be shown and described later.
Referring to
Only one of the first and second tools 21 and 22, in particular the first tool 21, may be configured movable and can be moved upwards and downwards as shown in the embodiment of
Molding apparatus 20 may further comprise a buffer cavity which is connected to the main cavity 23 by the passage 24. The buffer cavity may comprise a variable spatial volume.
Passage 24 may comprise a vertical dimension in a range less than 1000 μm, or less than 500 μm, or less than 100 μm, in particular 10 μm to 50 μm, more particular 20 μm to 40 μm.
Further examples of the molding apparatus 20 can be formed with any one of the features and embodiments as described above in connection with the molding apparatus 10 of
Referring to
Referring to
Referring to
It should be added that the carrier 48 or 58 used in the embodiments of
Referring to
The object can be comprised of a carrier panel, in particular a carrier panel with a plurality of devices like, for example, semiconductor devices, and the carrier panel can be covered with the mold material until the carrier panel and the devices are covered or encapsulated with the mold material up to a pre-defined height. The method can also be applicable to any other products or objects which need a precisely defined shape like, for example, a wing of a car.
The object can be comprised of a mold form comprising one or more recess areas in a surface thereof so that products of any desired form and shape can be fabricated out of the mold material.
Encapsulating the object with the mold material may comprise driving out excess mold material into the buffer cavity. A spatial volume of the buffer cavity can be varied as shown in the aspects and embodiments of
Covering the object with the mold material may comprise reducing a spatial volume of the main cavity. The molding apparatus may further comprise a first tool and a second tool, one of which is movable to form the main cavity between them, and covering the object with the mold material may comprise moving one of the first and second tools. This was shown, for example, in the embodiments of
The object may be placed in the main cavity but it is also possible that the object is placed in the main cavity is placed in both the main cavity and the buffer cavity or buffer cavities. For example, the object reaches from the main cavity through the passage into the buffer cavity so that in fact one boundary wall of the passage is given by the object extending through the passage. The object can also be placed in the buffer cavity or buffer cavities alone.
While the invention has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the invention.
