1. Field of the Invention
The present invention generally relates to an integrated circuit (IC) chip package and, particularly, to a digital camera module with an image sensor chip package.
2. Description of Related Art
Image sensors are widely used in digital camera modules in order to convert the optical image data of an object into electrical signals. In order to protect the image sensor from contamination or pollution (i.e. from dust or water vapor), the image sensor is generally sealed in a structural package.
A typical image sensor chip package (not labeled) is illustrated in
In the process of forming the conductors 130, a number of interconnection holes 166 are defined in the base 146. The first portions 140 and the second portions 142 are formed by means of plating metal. The third portions 136 are formed by filling molten metal into the interconnection holes 166 and then allowing it to solidify. Accordingly, the first portion 140, the second portion 142 and the third portion 136 are electronically connected with each other. It is obvious that this method of forming the conductors 130 is complex and as a result it is also expensive. Furthermore, after the conductors 130 are formed, water vapor can enter the space 150 via the interconnection holes 166. Thus, the chip 152 may be polluted and the conductors 130 may be damaged.
In addition, the relative large volume of the image sensor chip package results in more dust-particles adhering to the cover 158, the bottom board 1462 and the sidewalls 1464 of the base 146. Thus, more dust-particles will drop onto the chip 152. The dust-particles obscure the optical path and produce errors in the image sensing process. Accordingly, the quality and/or reliability of the image sensor chip package 100 can be effected. Moreover, the bonding wires 156 exposed in the space 150 lack protection and may thus easily be damaged by dust-particles entering the space 150.
Therefore, a new image sensor chip package is desired in order to overcome the above-described shortcomings.
One embodiment of a chip package includes a carrier, an image sensor chip, a plurality of wires, an adhesive means and a transparent cover. The carrier has a cavity therein. The image sensor chip is received in the cavity, and the image sensor has a photosensitive area. Each wire electronically connects the image sensor chip and the carrier. The adhesive means is applied to the image sensor chip around the photosensitive area and covers at least one portion of all the wires adjacent to the photosensitive area. The adhesive means forms an enclosing body around the photosensitive area. The transparent cover is mounted to the carrier, and the cover is adhered to the carrier with the adhesive means. The cover with the enclosing body surrounds a sealing space for enclosing the photosensitive area of the image sensor chip therein.
Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Many aspects of the present image sensor chip package can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the image sensor chip package. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, in which:
Referring to
The barrel 10 is substantially a hollow cylinder with two open ends so that light can be transmitted therethrough. Several lens elements 12 are disposed in the barrel 10, and receive incoming light that enters from the outside. The barrel 10 has an outer thread 102 defined in an outer periphery wall thereof. A glass board 14 is disposed before the lens elements 12 and covers one end of the barrel 10. As such, the glass board 14 protects the lens elements 12 from being scraped or otherwise abraded and keeps dust from entering the system.
The seat 20 includes a seat body 202 and a flange 204 formed together. The seat body 202 is a hollow cylinder. The flange 204 is formed at a bottom end of the seat body 202. The flange 204 has a rectangular cavity 2042 defined in a middle thereof opposite to the seat body 202. The rectangular cavity 2042 communicates with the seat body 202 so that light can be transmitted therethrough. An outer diameter of the seat body 202 is smaller than an edge of the flange 204 so that a step is formed at a connection between them. An inner periphery wall of the seat body 202 defines an inner thread 201, for engaging with the outer thread 102 of the barrel 10.
The carrier 32 of the image sensor chip package 30 includes a leadframe 320 and a plastic base 324. The leadframe 320 is embedded in the plastic base 324. The leadframe 320 and the plastic base 324 integrally form the carrier 32 by insert-molding. The carrier 32 has a receiving cavity 321 therein. The receiving cavity 321 has a bottom surface 3210, a slope surface 3212 and a support surface 3214. The support surface 3214 forms a plurality of upper pads 326 thereon spaced each other.
Referring to
During insert-molding, the plastic base 324 partially encloses the upper and lower surfaces of the leadframe 320. After insert-molding, the leadframe 320 is cut along two sides. Referring to
The cover 38 is transparent and is configured for being laid over the image sensor chip 34 for light to transmitted therethrough. The cover 38 is configured for disposing on the carrier 32 so as to seal the receiving cavity 321.
Referring to
The bonding wires 36 can be made of a conductive material such as gold or aluminum alloy. One end of each bonding wires 36 is connected/joined with a respective chip pad 342 of the image sensor chip 34, and the other end of the bonding wires 36 is connected/joined with a respective upper pad 326 forming by the first portions 3220 of the leadframe 320.
An adhesive glue 3262, such as a silicone, epoxy, acrylic, or polyamide adhesive, is applied to the top surface 341 of the image sensor chip 34 and around the image sensor chip 34. The adhesive glue 3262 not only covers the right side and the left side of the photosensitive area 344, but also covers an upper side and a lower side of the photosensitive area 344. The adhesive glue 3262 further covers the chip pads 342 and the bonding wires 36. In this embodiment, the adhesive glue 3262 also covers other areas around the image sensor chip 34. In addition, the adhesive glue 3262 covers both the upper pads 326 of the support surface 3214 and the slope surface 3212 of the receiving cavity 321. Portions of the enclosing body 3264 are filled in the trapezoidal space of the receiving cavity 321. Therefore, the adhesive glue 3262 surrounds the photosensitive area 344, thereby forming an enclosing body 3264 around the photosensitive area 344. The top view of the enclosing body 3264 shown herein for illustrative purpose is substantially rectangular, however, any other shapes such as square or irregular may also be used so long as the photosensitive area 344 is not covered.
Referring to
The enclosing body 3264 with the cover 38 in the closed band area 382 surrounds a small sealing space 37 configured to seal the photosensitive area 344 therein. It can be seen that the photosensitive area 344 of the image sensor chip 34 is sufficiently protected from outside pollution. Each wire electronically connects the image sensor chip and the carrier. The bonding wires 36 and the connection portion of the bonding wires 36 with the pads are protected by the adhesive glue 3262. Therefore, the characteristics of electronically connection effect may be maintained more stably. In addition, the small sealing space 37 is in the receiving cavity 321. The receiving cavity 321 is sealed by the cover 38, and the photosensitive area 37 is further sealed in the sealing space 37 by the enclosing body 3264. Therefore, the double protection for the photosensitive area 37 effectively prevents water vapor or dust from entering the interior of the package. One main advantage of the digital cameral module with this image sensor chip package is its reliability and high image quality.
In assembly for the image sensor chip package 30 and the lens module, firstly several lens elements 12 are received in the barrel 10. The outer thread 102 of the barrel 10 engages with the inner thread 201 of the seat 20, whereby the barrel 10 and the seat 20 are connected with each other. The seat 20 is then mounted on the image sensor chip package 30 by welding/glue, with the image sensor 34 aligning with the lens elements 12. At the same time, the cover 38 is received in the rectangular cavity 2042. The assembly process of the digital camera module is thus completed.
In an alternative embodiment, referring to
In an alternative embodiment, the arrangement of the conductive pieces of the leadframe 320 can be changed so long as the conductive pieces 322 are spaced from each other. The second portion 3222 can be perpendicular to the first and third portions 3220, 3224 rather than being slanted. The base 324 can be of another shape such as cylinder-shaped, or column-shaped with a pentagonal or hexagonal cross-section.
Understandably, the distance between the enclosing body 3264, 3266 and the photosensitive area 344 may be adjusted.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
This application is a continuation-in-part application of U.S. application Ser. No. 11/448,314, filed on Jun. 7, 2006.
Number | Date | Country | |
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Parent | 11448314 | Jun 2006 | US |
Child | 12151369 | US |