Patent Application
20090289376
The present invention relates to a chip packaging structure, particularly to a light-proof chip packaging structure, which can protect a semiconductor chip from light radiation.
The Smart Card is a plastic card wherein an IC chip is embedded; therefore, it is also called the IC Card or ICC (Integrated Circuit Card). As an integrated circuit chip (hereinafter called IC chip for short) has the functions of storing, encrypting and processing data, it has been used in many fields, such as finance, communication, trading, verification, personal identification, etc. More specifically, it can be used for credit cards, electronic wallets, and personal identity cards. US patents of U.S. Pat. No. 7,341,198, U.S. Pat. No. 7,337,978, and U.S. Pat. No. 7,293,717 disclose the above-mentioned integrated circuit chip in the related technologies. In addition to an IC chip, the Smart Card also has a high capacity slim battery driving circuits on the electronic substrate.
However, heat may cause current leakage, lower the performance of circuits, or even damage the IC chip. Limited by its dimensions, the Smart Card has no heat-dissipation component. Smart cards are normally carried about by users and likely to be exposed to external environments. Direct light or scattered light may pass through the surface of the Smart Card and reach the IC chip and then is converted into heat to raise the temperature of the IC chip, which will degrade the stability of the IC chip, lower the endurance of the battery, and thus shorten the lifetime of the Smart Card.
The primary objective of the present invention is to solve the problem of gaps between an IC chip and a light-proof material for packaging a Smart Card. The gap often causes the formation of bubbles, which damages the packaging structure of the Smart Card.
To achieve the abovementioned objective, the present invention proposes a light-proof chip packaging method, which comprises steps: (a) installing one or more semiconductor chip, wherein at least one semiconductor chip is installed on an electronic substrate; (b) covering the semiconductor chip and its neighboring areas with a light-proof film, wherein the light-proof film comprises a metallic layer and an insulating layer; and (c) applying pressure to the light-proof film to cause the light-proof film to be substantially conformable to cover all non-concealed faces of the semiconductor chip and the areas neighboring the semiconductor chip.
The method may further comprise adding an adhesive layer to the light-proof film to cause the light-proof film to be substantially conformable to adhere to all the non-concealed faces of the semiconductor chip by pressure.
The present invention also proposes a light-proof chip packaging structure, which comprises: an electronic substrate, at least one semiconductor chip installed on the electronic substrate, and a light-proof film. The light-proof film comprises a main portion, which is substantially conformable to the shape of the semiconductor chip, and covers all the non-concealed faces of the semiconductor chip. The light-proof film also has an extension portion, which extends from the main portion and covers the areas neighboring the semiconductor chip. The light-proof film comprises a metallic layer capable of blocking light and an insulating layer interposing between the metallic layer and the semiconductor chip. In one embodiment of the present invention, the light-proof film further comprises an adhesive layer interposing between the insulating layer and the semiconductor chip, whereby the light-proof film can be adheres to the semiconductor chip.
In the present invention, a light-proof film having plasticity is used to cover the semiconductor chip, and a slight pressure is applied to the light-proof film to make the light-proof film substantially conformable to all the non-concealed faces of the semiconductor chip. Thereby, the gaps between the light-proof film and the semiconductor chip are eliminated, and no bubble will form in the packaging process of the Smart Card. Thus, the Smart Card is perfectly encapsulated, and the circuits on the electronic substrate will operate normally.
Below, the technical contents of the present invention will be described in detail in cooperation with the drawings.
In this embodiment, the semiconductor chip and the electronic substrate are to be used in a Smart Card. Thus, after Step S30, there is a Step S40 for packaging the Smart Card, wherein the electronic substrate is encapsulated with a plastic material. Besides, the light-proof film further comprises an adhesive layer, whereby the light-proof film can be substantially conformable to adhere to all the non-concealed faces of the semiconductor chip by pressure in Step S30. Before Step S40, the present invention uses a light-proof film having plasticity to cover the semiconductor chip, and a pressure is applied to the light-proof film to make the light-proof film substantially conformable to cover all the non-concealed faces of the semiconductor chip and the areas neighboring the semiconductor chip. Thereby, the gaps between the light-proof film and the semiconductor chip are eliminated, and no bubble will form in Step S40.
The present invention also proposes a light-proof chip packaging structure.
The light-proof chip packaging structure of the present invention is applicable to many electronic devices, such as Smart cards, RFID (Radio Frequency Identification) tags, or other slim electronic devices.
In the present invention, a light-proof film 30 having plasticity is arranged on a semiconductor chip 20, and a pressure is applied to the light-proof film 30 to make the light-proof film 30 substantially conformable to cover all the non-concealed faces of the semiconductor chip 20 and the areas neighboring the semiconductor chip 20. Thereby, the gaps between the light-proof film 30 and the semiconductor chip 20 are eliminated, and no bubble will form in the packaging process of the Smart Card.
From the above description, the present invention represents improvements over the prior arts and meets the conditions for a patent.
The preferred embodiments described above are only to exemplify the present invention but not to limit the scope of the present invention. Therefore, any equivalent modification or variation according to the spirit of the present invention is to be also included within the scope of the present invention.
