Patent Application
20080142573
This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 095147376 filed in Taiwan, Republic of China on Dec. 18, 2006, the entire contents of which are hereby incorporated by reference.
1. Field of Invention
The invention relates to a package structure and, in particular, to a package structure for a lead-free process.
2. Related Art
The environmental protection is one of the most considerations in the recent years. Regarding to this issue, many electronic products have been manufactured with lead-free materials and by lead-free manufacturing processes. In a lead-free process, such as a soldering process for mounting a surface mounted device (SMD) on a circuit board, the solder process provides a high temperature and it is easier to melt the SMD and the circuit board, so the thermal durability of the SMD and the circuit board must be enhanced. As shown in
However, the lead-free process is usually operated around 260° C. Therefore, if the thermal durability of the package portions 11 and 12 is poor, the package structure may crack and the electronic element may be damaged. These problems will decrease the reliability and lifetime of the electronic products.
Therefore, it is an important subject to provide a package structure suitable for the lead-free process, wherein the thermal durability of the package structure is enhanced and the unchanged layout of the electronic elements on the circuit board is necessary.
In view of the foregoing, the invention is to provide a package structure suitable for the lead-free process, which can solve the crack problem of the package structure caused by the poor thermal durability in the lead-free process. Thus, the reliability, lifetime and yield of the package structure can be increased and the manufacturing cost can be decreased.
In addition, the invention is also to provide a package structure suitable for the lead-free process, which can minimize the size of the electronic products and occupy less space on the circuit board.
To achieve the above, the invention discloses a package structure for a lead-free process, which includes at least one electronic element, a first package portion and a second package portion. The electronic element has a plurality of pins. The second package portion and the first package portion are joined to encapsulate the electronic element and form a molding area. The first package portion has an extension protruding from the molding area. The pins extend from the molding area and contact the extension of the first package portion.
As mentioned above, the package structure of the invention includes a package portion having an extension protruding from the molding area, so that the pins of the electronic element can extend from the molding area and contact the extension of the first package portion. Compared with the prior art, the invention can buffer the thermal expansion effect during the lead-free process by the different sizes of the package portions, and the unchanged layout of the electronic element on the circuit board. Thus, the crack of the package structure can be prevented, and the package structure can have better thermal durability in the leadless process. Accordingly, the reliability, lifetime and yield of the package structure can be increased and the manufacturing cost can be decreased.
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
With reference to
The first package portion 21 has an extension 21a protruding from the molding area 2122. That is, the sizes of the first package portion 21 and second package portion 22 are different. This different can buffer the thermal expansion effect during the lead-free process. Thus, the crack of the package structure 2 can be prevented, and the thermal durability of the package structure 2 in the lead-free process is enhanced. In the embodiment, the size of the first package portion 21 is larger than that of the second package portion 22. The pins 23 of the electronic element contact the extension 21a of the first package portion 21 so as to form an SMD.
As shown in
In summary, the package structure of the invention includes a package portion having an extension protruding from the molding area, so that the pins of the electronic element can extend from the molding area and contact the extension of the first package portion. Compared with the prior art, the invention can buffer the thermal expansion effect during the lead-free process by the different sizes of the package portions, and the unchanged layout of the electronic element on the circuit board. Thus, the crack of the package structure can be prevented, and the package structure can have better thermal durability in the lead-free process. Accordingly, the reliability, lifetime and yield of the package structure can be increased and the manufacturing cost can be decreased.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 095147376 | Dec 2006 | TW | national |
