JP2533001B2 - Method of manufacturing solid-state image sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a resin mold type CC.
The present invention relates to a method for manufacturing a solid-state image sensor such as a D image sensor.

[0002]

2. Description of the Related Art The structure of a conventional solid-state image pickup device using a ceramic package is shown in FIG. An internal lead 3a and an external lead 3b continuous with the internal lead 3a are embedded in advance in the ceramic package 1. The external lead 3b exposed to the outside is connected to a drive circuit or the like for driving an image sensor.
A recess is formed in the ceramic package 1, and the sensor chip 2 having the photoelectric conversion element formed on one surface is housed in the recess. Then, the electrode pad of the sensor chip 2 is connected to the tip of the internal lead 3a exposed in the recess by wire bonding. Furthermore, the sensor chip 2
The concave portion in which is stored is sealed by mounting the glass plate 4.

However, in the solid-state image pickup device as described above, when the sensor chip 2 is bonded in the concave portion of the ceramic package 1 and then the sensor chip 2 and the internal lead 3a are wire-bonded, color image pickup is performed. Further, since many assembling steps such as mounting a color filter are required, the cost is increased, and dust is frequently attached to the light receiving surface of the sensor chip 2 in the assembling step. Further, since the ceramic package 1 itself is expensive, the reduction in yield in the assembly process is one of the major factors for cost increase.

Therefore, it has been proposed, for example, in Japanese Utility Model Laid-Open No. 1-113347 to mold the sensor chip with a transparent resin. If the sensor chip is molded with such a translucent resin, the assembly process is simplified as compared with the case where the ceramic package 1 is used, and an inexpensive solid-state imaging device can be provided. In addition, the applicant of the present application has also proposed in Japanese Patent Application No. 2-111923 to form an image pickup device by molding a sensor chip with a translucent resin.

FIG. 7 shows a method of forming a sensor chip package with a light-transmitting resin. The lead frame includes an island portion 11 to which the sensor chip 10 is die-bonded, and lead portions 1 arranged around the island portion 11.
2 and an outer frame 13 surrounding the lead portion 12, the sensor chip 10 is attached to the island portion 11, the pad portion of the sensor chip 10 and the tip of the lead portion 12 are wire-bonded, and the lead portion 12 is also the island portion. 11
After being bent perpendicularly to the concave part 2 of the mold 20
It is stored in 1. The recess 21 of the mold 20 is formed according to the shape of the image pickup device to be obtained, and as shown in FIG. 8, a step portion 22 that supports the lead frame 11 and a positioning pin that fixes the position of the lead frame. 23 are provided. Therefore, the position of the sensor chip 10 with respect to the bottom surface of the recess 21 of the mold 20 is determined by the step portion 22, and the position of the sensor chip 10 with respect to the side surface is determined by the positioning pin 23.

The lead frame in which the sensor chip 10 is mounted on the island portion 11 is housed in the recess 21 with the side on which the sensor chip 10 is mounted facing the bottom side of the recess 21, and is a thermosetting translucent resin. It is molded by. The translucent resin is filled in the recess 21 after the lead frame is housed in the recess 21, and is cured by being heated to form a package. When the translucent resin is heat-cured as described above, bubbles contained in the translucent resin are expelled to the outside of the resin during curing, so that no bubbles are generated in the translucent resin. . Then, the formed package is taken out from the mold 20, and the outer frame 13
When the lead portion 12 and the lead portion 12 are cut off, a solid-state image sensor is obtained as shown in FIG. In this solid-state image sensor, the back surface of the translucent resin is not flat, and the reference plane when the image sensor is mounted on the substrate cannot be accurately obtained.
A part of 3 is left for the determined length, and the left outer frame 13
Is configured to obtain a reference plane from the tip of the.

[0007]

However, since the thermosetting translucent resin shrinks during curing, the translucent resin on the front surface side and the back surface side of the island portion 11 as shown in FIG. 9 is used. If there is a difference in volume, excessive stress will be applied to the island portion 11. Therefore, the sensor chip 10 may be distorted or the translucent resin may be separated from the lead frame in some cases, and high reliability cannot be obtained.

The mold 20 is preferably simpler.
The sensor chip 1 with respect to the bottom surface of the recess 21
Since the step portion 22 for determining the position of 0, that is, the position of the sensor chip 10 with respect to the surface of the translucent resin is provided, there is a problem that the translucent resin is difficult to mold and the productivity is reduced. . Therefore, an object of the present invention is to improve the reliability of the mold resin and to simplify the package shape to prevent the productivity from decreasing.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a first feature that it is a semiconductor in which a plurality of photoelectric conversion elements are arranged in a matrix. While mounting the chip on the island portion of the lead frame, bending the lead portion of the lead frame substantially perpendicular to the semiconductor chip, and housing the lead frame with the semiconductor chip mounted in the recess forming the package shape. In the method for manufacturing a solid-state imaging device, the step of heating the translucent resin by filling the inside of the recess with a thermosetting translucent resin, and curing the translucent resin, A first protrusion that determines the position of the lead frame and a second protrusion that determines the position of the lead frame with respect to the bottom surface of the recess are substantially aligned with the bottom surface of the recess. Some that are directly provided.

A second feature is that in the method of manufacturing a solid-state image pickup device, a part of the lead frame is bent in a direction opposite to the lead part, and the tip of the bent part is formed on the bottom surface of the recess. A protrusion that determines the position of the semiconductor chip with respect to the bottom surface of the recess by making contact with each other and determines the position of the lead frame with respect to the side surface of the recess is provided substantially perpendicular to the bottom surface of the recess. .

[0011]

According to the present invention, the shape of the recess for obtaining the package shape is simplified, and the volumes of the translucent resin on the front surface side and the back surface side of the lead frame are equal, so that the translucent resin is molded. In addition to being easy, no extra stress is applied to the island portion of the lead frame. Therefore, it is possible to efficiently produce a highly reliable image sensor.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a method of manufacturing the solid-state image sensor of the present invention. In this figure, the sensor chip 10 and the lead frame are shown in FIG.
The same parts are designated by the same reference numerals.

In the lead frame in which the sensor chip 10 is mounted on the island portion 11, after the lead portion 12 is bent, as in the case of FIG. 7, the sensor chip 10 side is placed on the bottom surface side in the recess 31 of the mold 30. It is stored. The recess 31 of the mold 30 in which the lead portion 12 is housed is a rectangular parallelepiped having no step, and the support pin 32 that supports the lead frame and the positioning pin that determines the position of the island portion 11 of the lead frame. 33 is provided perpendicularly to the bottom surface of the recess 31. The support pins 32 are provided at least at three points in the recess 31, and the lead frame is attached to the outer frame 34.
It is supported by the portion or the lead portion 12. However, since a hole is formed at the position where the support pin 32 is provided after the light-transmitting resin is cured, the support pin 32 is preferably provided at a position apart from the sensor chip 10 mounted on the island portion 11. . Then, the positioning pin 33 is coupled with a positioning hole provided in the island portion 11 of the lead frame to determine the position of the sensor chip 10 with respect to the recess 31, that is, the position of the sensor chip 10 with respect to the package. Therefore, the position of the bottom surface of the recess 31 and the sensor chip 10 is determined by the support pin 32, and the position of the side surface of the recess 31 and the sensor chip 10 is determined by the positioning pin 33.

After the lead frame is housed at a predetermined position in the recess 31, a thermosetting translucent resin is filled in the recess 31, and the translucent resin is heated together with the lead frame to transmit light. Resin is cured. At this time, since the volume of the translucent resin on the front surface side and the back surface side of the island portion 11 of the lead frame is substantially equal, the contraction of the translucent resin on both sides of the island portion 11 is even. Then, after the translucent resin is cured to form the package, the translucent resin package is taken out and the lead portion 1
2 and the outer frame 34 are cut to obtain a solid-state image sensor. As shown in FIG. 2, the solid-state image sensor manufactured in this way is
The transparent resin package has an extremely simple shape, and the transparent resin can be easily molded.

With the above structure, a package having a simple shape and a well-balanced volume of the transparent resin can be obtained. Therefore, the internal stress generated by the contraction of the transparent resin at the time of curing is sensor chip. It is possible to obtain a solid-state image sensor with high reliability, which is less likely to adversely affect 10, and to improve productivity by simplifying the package shape.

Next, another embodiment of the manufacturing method of the present invention is shown in FIG. The lead frame on which the sensor chip 10 is mounted is the island portion 1 on which the sensor chip 10 is mounted.
1. The lead portion 12 and the outer frame 13 arranged in the periphery of the island portion 11, and the support portions 14 are provided at both end portions of the island portion 11. This support 1
4 is bent in a direction opposite to the direction in which the lead portion 12 is bent, and is configured to support the island portion 11. That is, the lead frame is, as shown in FIG.
In addition to the island portion 11 and the lead portion 12 being provided to be surrounded by the outer frame 13, the island portion 11
Support portions 14 having a constant width are provided so as to project on the outer frame 13 portions on both sides, and the lead portion 12 is bent perpendicularly to the island portion 11 at a position shown by a broken line in FIG. 14 is bent perpendicularly to the island portion 11 in the direction opposite to the lead portion 12. In addition, a positioning hole is provided near the end of the island portion 11.

The mold 40 for accommodating the lead frame on which the sensor chip 10 is mounted is provided with a recess 41 forming a rectangular parallelepiped, like the mold 30 shown in FIG. A positioning pin 42 for fixing the position of is provided perpendicularly to the bottom surface. Therefore, when the lead frame is housed in the recess 41 of the mold 40, the position of the sensor chip 10 with respect to the side surface of the recess 41 is determined by the positioning pin 42, and the support portion 14 of the lead frame causes the gap between the bottom surface of the recess 41 and the sensor chip 10. Is determined. Then, a thermosetting translucent resin is filled in the recess 41 in which the lead frame is housed, and the translucent resin is heated to cure the translucent resin to form a package. The outer frame 13 and the lead portion 12 are cut. In the solid-state imaging device obtained here, as shown in FIG. 4, since the volume of the translucent resin on the front surface side and the back surface side of the island portion 11 are equal, the balance of the stress generated by the contraction during curing is improved. Therefore, the sensor chip 10 is not adversely affected. In addition, the concave portion 4 of the mold 40
The shape of 1 is simpler than that of the mold 40 of FIG. 1, and since unnecessary holes are not formed when the translucent resin is cured, molding of the translucent resin is easier and the productivity is further improved. To be done. However, since the step of forming the support portion 14 of the lead frame is required, the productivity is not always higher than that of the manufacturing process shown in FIG. 1 in consideration of the entire manufacturing process.

By the way, the support portions 14 provided on the lead frame may be provided not only on the outer frame 13 portions on both sides of the island portion 11 as shown in FIG. To be According to the above configuration, in any of the cases of FIG. 1 and FIG. 3, the package shape is simple and the volume of the transparent resin is well balanced, so that the transparent resin can be easily molded. You can
The influence of internal stress due to the contraction of the translucent resin at the time of curing does not reach the sensor chip 10.

[0019]

According to the present invention, by simplifying the shape of the mold, that is, the shape of the package, molding of the translucent resin is facilitated and the productivity can be improved. And
The balance of the translucent resin is improved and unnecessary stress is not applied to the sensor chip even when the translucent resin shrinks during curing, so it is possible to prevent distortion of the sensor chip and cracking of the package resin, and solid-state imaging The reliability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating an embodiment of the present invention.

FIG. 2 is a side view of a solid-state imaging device obtained by the manufacturing method of FIG.

FIG. 3 is a sectional view illustrating another embodiment of the present invention.

FIG. 4 is a side view of a solid-state imaging device obtained by the manufacturing method of FIG.

FIG. 5 is a plan view of a lead frame used in the manufacturing method of the present invention.

FIG. 6 is a perspective view showing a structure of a conventional solid-state image sensor.

FIG. 7 is a cross-sectional view illustrating the method of manufacturing the solid-state image sensor.

FIG. 8 is a perspective view showing a structure of a mold.

9 is a side view of a solid-state imaging device obtained by the manufacturing method of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic package 2, 10 Sensor chip 3a External lead 3b Internal lead 4 Glass plate 11 Island part 12 Lead part 13 Outer frame 14 Support part 20, 30, 40 Mold 21, 31, 41 Recessed part 22 Step part 23, 33, 42 Positioning pin 32 Support pin

Claims (2)

(57) [Claims] 1. A step of mounting a semiconductor chip having a plurality of photoelectric conversion elements arranged in a matrix on an island portion of a lead frame, and bending the lead portion of the lead frame substantially perpendicular to the semiconductor chip, A step of accommodating the lead frame in which the semiconductor chip is mounted in a recess having a package shape, filling the inside of the recess with a thermosetting translucent resin, and then heating to cure the translucent resin; In the method of manufacturing a solid-state imaging device, including: a first protrusion that determines a position of the lead frame with respect to a side surface of the recess, and a second protrusion that determines a position of the lead frame with respect to a bottom surface of the recess. Are provided substantially perpendicular to the bottom surface of the recess, and a method for manufacturing a solid-state image sensor. 2. A step of mounting a semiconductor chip having a plurality of photoelectric conversion elements arranged in a matrix on an island portion of a lead frame and bending the lead portion of the lead frame substantially perpendicular to the semiconductor chip, A step of accommodating the lead frame in which the semiconductor chip is mounted in a recess having a package shape, filling the inside of the recess with a thermosetting translucent resin, and then heating to cure the translucent resin; In the method for manufacturing a solid-state image pickup device including: a part of the lead frame is bent in a direction opposite to a lead part, and a tip part of the bent part is brought into contact with a bottom surface of the recess to position the semiconductor chip with respect to a bottom surface of the recess. In addition, a protrusion that determines the position of the lead frame with respect to the side surface of the recess is formed substantially in the recess. A method for manufacturing a solid-state imaging device, which is provided vertically.