JP2006324304A - Semiconductor package and image sensor type module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor package which is low in cost, compact, thin, and highly reliable by high-density mounting technique, and to provide an image sensor type module of a camera which is used for a cellular phone or peripheral devices of a computer. <P>SOLUTION: A semiconductor chip (102) wherein a bump (109) is formed on a pad electrode (108) is mounted by flip chip to a substrate (101) wherein a hole is formed in a central part, a circuit pattern is formed and an outer connection (111) is provided. Next, a joint between the semiconductor chip (102) and the substrate (101) and a side surface of the semiconductor chip (102) are sealed, and then the hole of the central part is hermetically sealed by a cover glass (104). The outer connection (111) arranged outside the semiconductor chip surface is bent into U-shape, and it is mounted to the rear surface of the semiconductor chip (102). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technology for a light, thin, and small semiconductor package. As an application, it is also applied to an image sensor module used for camera image recognition.

JP 2001-308140 A

  In recent years, the density of semiconductor package mounting has been increasing. The form is widely adopted from the conventional QFP (Quad Flat Package) to an area array-like BGA (Ball Grid Array) or CSP (Chip Size Package), which is almost the same as the chip size. In addition, the package for camera modules mounted on mobile phones is also becoming smaller.

  There is a flip chip mounting method as a mounting method for realizing these high-density mountings. An example of a conventional flip chip mounting package is shown in FIG. The flip chip mounting method is a method in which protrusions called bumps are provided on a pad electrode of a semiconductor chip and connected to an interposer. The bump is made of a material such as Au, Cu, or Pb-Sn, and is formed using a photolithography technique and a plating technique.

  On the other hand, Au or Cu bumps can be formed in a ball shape using wire bonding technology. After bump formation, face down bonding is performed on the interposer to make electrical connection. Unlike the wire bonding method, the flip chip method can be connected to the interposer at a short distance, so that signal processing can be performed at higher speed and higher density mounting.

  On the other hand, in this flip chip system, stress is generated in the joint due to the difference in thermal expansion between the semiconductor chip and the interposer, and the reliability of the joint is impaired. The reliability of this flip-chip bonding depends on the difference in thermal expansion coefficient. First, the thermal expansion coefficient of the semiconductor chip is 3.5 ppm. When a wiring board made of, for example, polyimide is used for the interposer, the thermal expansion is achieved. The coefficient is about 16 ppm. For example, assuming that the chip size is 10.5 mmsq, it is assumed that the bump farthest from the center of the chip is at a position of 5 mm. Then, the difference in thermal expansion coefficient is 16−3.5 = 12.5 ppm / ° C., and the dimensional difference is 5 × 12.5 / 1,000,000 = 0.0000625. That is, a strain of 0.0625 μm is generated per 1 ° C. In the temperature cycle used in the reliability test, for example, if a temperature difference of 150 ° C. occurs, it becomes 9.375 μm, and if the diameter of the joint is 100 μm, a large distortion of 9.375% occurs.

  Therefore, as shown in FIG. 11B of Patent Document 1, an underfill resin is injected between the semiconductor chip and the interposer to disperse the concentrated stress on the bump portion, thereby improving the reliability. Has been taken.

  However, in the underfill method, since resin is injected from the periphery of the chip into the semiconductor chip and interposer after bonding, air is easily trapped and voids are formed, which causes expansion rupture and loss of reliability due to moisture absorption reflow tests. Have. As a method for solving these problems, Patent Document 1 adopts a structure in which a sealing resin as an adhesive is formed in advance on a semiconductor chip on which bumps are formed and connected to an interposer. According to this method, sufficient reliability can be secured without using underfill. However, the method of forming the adhesive after the bumps are formed is considered to be easy to form in a wafer state because positioning is difficult to form on a chip of individual pieces diced from a semiconductor wafer.

  However, defective semiconductor chips are included in the wafer, and the material cost of the adhesive is wasted. In mounting an image sensor type chip, since the image recognition sensor portion cannot be sealed, it is necessary to cut out the adhesive in that portion in advance. However, it has been substantially difficult to position and cannot be formed. Further, when the semiconductor chip and the substrate are bonded, the adhesive flows out and covers the image recognition sensor portion, which makes it difficult to manufacture. For these reasons, as shown in FIGS. 7 and 8, a normal image sensor type module employs a wire bonding method in which a structure can be easily completed from a normal package, which hinders downsizing. It was.

  An object of the present invention is to provide an inexpensive, small, thin, and highly reliable semiconductor package by high-density mounting technology. It is another object of the present invention to provide an image sensor type module for a camera used as a peripheral device of a mobile phone or a computer.

  In order to achieve the above object, a semiconductor package according to claim 1, wherein a semiconductor chip having a bump formed on a pad electrode is flip-chip mounted on a substrate having a hole in the center and a circuit pattern formed thereon. Then, the joint between the semiconductor chip and the substrate and the side surface of the semiconductor chip are sealed, the hole in the center of the substrate is sealed with a cover glass, and one end of the substrate is extended in one direction. It has the provided outer connection part, It is characterized by the above-mentioned.

  The semiconductor package according to claim 2, wherein the substrate is made of a flexible substrate such as polyimide, an outer connection portion having an outer pad is disposed on the substrate, and a hole slightly smaller than an outer pad diameter is formed in the outer pad portion. The substrate provided with is characterized in that the outer peripheral portion of the semiconductor chip is bent in a U shape and disposed on the back surface of the semiconductor chip for mounting.

  According to a third aspect of the present invention, in the semiconductor package, the outer connecting portion is formed of a second outer pad portion formed by solder, ACF (Anisotropic Conductive Film) resin, or the like at a pitch wider than the pad pitch of the outer pad portion. It connected to the board | substrate which has.

  The semiconductor package according to claim 4, wherein the outer connection portion is connected to a substrate extending in at least one direction having a second outer pad for connection to the outside by solder, ACF resin, or the like. And

  The semiconductor package according to claim 5 uses a flexible substrate as a substrate on which a circuit pattern is formed, and in a substrate on which an outer connection portion having an outer pad is arranged, wire or the like is soldered to the outer pad. The flexible board is connected and bent to the back side of the semiconductor chip and arranged in an L shape with the semiconductor chip.

  The image sensor type module according to claim 6, wherein a flexible substrate is used as a substrate on which a circuit pattern is formed, and the outer pad is a second substrate in a substrate on which an outer connection portion having an outer pad is arranged. In addition, a wire or the like is connected to the outer pad of the second substrate with solder or the like, the flexible substrate is bent to the back side of the semiconductor chip, and the second substrate is formed into an L shape with the semiconductor chip. A lens kit having a cover glass or the like is provided at the center of the opened substrate.

  A semiconductor package according to claim 7 is the semiconductor package according to claim 1, claim 2, claim 3, or claim 4, wherein the circuit pattern is formed in the substrate center with a hole. The hole at the center of the substrate is sealed with resin.

  The semiconductor package or image sensor type module according to claim 8 is the semiconductor package or image according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, or claim 7. In the sensor-type module, a UV curable resin is used as a sealing material for the bonding portion between the semiconductor chip and the substrate, the side surface portion of the semiconductor chip, and the cover glass.

  According to the first or second aspect of the present invention, a small, thin and highly reliable semiconductor package can be provided at low cost by using a flip chip method which is advantageous for high density at high speed.

  According to the invention according to claim 3 or claim 4, since the outer pitch required for batch reflow mounting can be obtained by using an interposer such as a multi-layer substrate, the outer disposed on the back surface of the semiconductor chip after being bent in a U shape It is possible to make the connection portion within the size of the semiconductor chip. In addition, electrical bonding can be easily performed by thermocompression bonding with the second substrate using an ACF resin or the like.

  According to the invention according to claim 5 or claim 6, a flexible substrate is used as the substrate on which the outer connection portion is arranged, and the outer connection portion is bent in an L-order shape on the back surface side of the semiconductor chip. By bundling a plurality of wires connected to the outer pad in a cable shape, the smallest image sensor type module can be formed.

  According to the invention of claim 7, by applying a sealing resin to the surface of the semiconductor chip by a potting method or the like, the hole at the center of the substrate is sealed with the resin, so that the same small and thin semiconductor as described above is used. A package can be formed.

  According to the invention according to claim 8, by using the UV curable resin as a sealing material for the bonding portion of the semiconductor chip and the substrate, the side surface portion of the semiconductor chip, and the cover glass, it is possible to prevent the resin from flowing out into the inside. Can do.

  Next, the best mode for carrying out the present invention (hereinafter simply referred to as “embodiment”) will be described. In addition, this invention is not limited by this embodiment.

Hereinafter, it demonstrates in detail based on drawing. FIG. 1 is a cross-sectional view and a plan view showing a first embodiment. The semiconductor chip (102) to be mounted here is for an image sensor.
In the semiconductor package of FIG. 1, a semiconductor chip (102) having a bump (109) formed on a pad electrode (108) is flipped onto a substrate (101) having a hole in the center and a circuit pattern formed. Performing chip mounting, and then sealing the joint between the semiconductor chip (102) and the substrate (101) and the side surface of the semiconductor chip (102), sealing the hole in the center with a cover glass (104), and It has an outer connection part (111) provided by extending one end of the substrate in one direction.

  Further, the substrate (101) is made of a flexible substrate such as polyimide, the substrate is provided with an outer connecting portion (111) having an outer pad (110), and the outer pad portion has a hole slightly smaller than the outer pad diameter. In the substrate provided with, the outer peripheral portion of the semiconductor chip (102) is bent in a U shape and disposed on the back surface of the semiconductor chip for mounting.

Next, a method for manufacturing the semiconductor package of FIG. 1 will be described.
A substrate (101) on which wiring for connecting the semiconductor chip (102) and the outside is formed on a surface other than the portion positioned in the image recognition sensor circuit portion (103) is formed. Thereafter, a substrate (101) is prepared by removing a portion corresponding to the sensor circuit portion with a mold or the like. Next, bumps (109) are formed on the pad electrodes (108) of the semiconductor chip. The bump (109) may be either a plating method or a ball bump method. The wiring is made of copper, but the surface is tin-plated, and the bump (109) is made of Au, and bonding is performed by thermocompression bonding at 300 ° C for about 10-30 seconds with a load of 1N / bump. With this, Au—Sn eutectic alloy connection can be made. Next, a resin is formed on the bump portion and the side portion of the semiconductor chip (102). Since a hole is formed in the central portion of the semiconductor chip (102), air is confined and does not become a void. In the case of an image sensor chip, if the resin is applied to the image recognition sensor circuit portion (103), it becomes defective. Next, the resin is cured by baking at 100 to 150 ° C. for about 60 to 120 minutes. Next, a small amount of resin is applied and a cover glass (104) is attached. Thereafter, the resin is cured by baking. Then, it is completed by cutting into a desired package shape.

  Here, in the image recognition sensor circuit unit (103), if there is an object that obstructs recognition within the upper angle of 60 degrees, a problem occurs. In particular, when the image recognition sensor circuit unit (103) is positioned at the end of the chip, the distance from the pad electrode (108) is very short, so that there is a problem that the resin flows and covers it. In the case of a thermosetting resin, the solvent contained in the resin may initially flow out due to heat and may enter the opening when baking after a small amount of application. In order to solve this problem, it is effective to use a UV curable resin for the connection sealing portion (106).

Next, a method for using the UV curable resin will be described.
First, a small amount of UV curable resin is applied. Thereafter, the resin can be cured in a substantially applied state by irradiating with UV without applying heat, so that it is possible to prevent the resin from flowing out into the inside. Further, when a UV curable resin is also used for the sealing portion (105) of the cover glass (104), it can be also UV-cured after a small amount of coating to prevent flow-out. Then, for strengthening the strength, UV curing resin or thermosetting resin is applied to the side of the semiconductor chip (102) and the side of the cover glass (104) and cured to prevent outflow and strengthen the strength. Can also form a product. After cutting, the outer connection part (111) formed on at least one side is bent 180 degrees on the back side of the semiconductor chip (102) and fixed to the back side of the semiconductor chip (102) with a fixing adhesive, so that a chip size package can be obtained. It is formed. At this time, the outer pads (110) may be arranged in a lattice pattern to form solder balls for the BGA package.

Next, as a second embodiment, the surface of the semiconductor chip may be covered with resin as in an image sensor package. FIG. 2 is a sectional view and a plan view showing the second embodiment.
As shown in FIG. 2, a chip-sized package similar to that of the first embodiment can be formed by applying the sealing resin (203) by a potting method or the like.

Next, a third embodiment will be described. 3 and 4 are sectional views showing a third embodiment.
In the semiconductor package of FIG. 3, the outer connection portion (307) is formed on a substrate having a second outer pad portion (306) formed by a solder, ACF resin, or the like at a pitch wider than the pad pitch of the outer pad portion (305). It has a connected structure.

  In the semiconductor packages of the first and second embodiments, since the outer connecting portion needs to be within the size of the semiconductor chip, even if the outer pads are arranged in a lattice like the BGA, the multi-pin If it becomes, the pitch will become very narrow. For this reason, batch reflow to the mounting board may not be easy. For this reason, as shown in FIG. 3, if an interposer (303) such as a multilayer board is used, the outer pitch required for batch reflow mounting can be achieved. The package of the first embodiment is placed on the inner pad of the interposer by image recognition, for example, and joined with solder or the like. The joint is then reinforced with a resin such as underfill. At this time, since the substrates are bonded to each other, the thermal expansion coefficient is almost the same, so that the stress becomes low and sufficient reliability can be secured. On the other hand, electrical bonding can be easily performed by thermocompression bonding using an ACF resin or the like.

FIG. 4 shows the case of an image sensor package.
The semiconductor package of FIG. 4 has a structure in which an outer connection portion (407) is connected to a substrate extending in at least one direction having a second outer pad (408) for connecting to the outside by solder, ACF resin, or the like. . As shown in FIG. 4, the second substrate having a desired shape and material can be easily formed by bonding with solder or ACF resin.

Next, a fourth embodiment will be described. This embodiment is an image sensor type module formed in a cable shape. 5 and 6 are sectional views showing a fourth embodiment.
The semiconductor package of FIG. 6B uses a flexible substrate for the substrate (601) on which the circuit pattern is formed, and the outer pad (605) is disposed on the substrate on which the outer connection portion having the outer pad is arranged. A wire or the like (609) is connected by solder or the like, and the flexible substrate (601) is bent to the back side of the semiconductor chip (602) and arranged in an L shape with the semiconductor chip.

  Furthermore, the semiconductor package of FIG. 6A uses a flexible substrate as the substrate (601) on which the circuit pattern is formed, and the substrate (601) in which the outer connection portion having the outer pad (605) is arranged. The outer pad (605) is bonded to the second substrate (610), and further, a wire or the like is connected to the outer pad (608) of the second substrate (610) with solder or the like, so that the flexible substrate is obtained. The second chip (610) is bent in the L-shape with the semiconductor chip, and a lens kit having a cover glass (603) or the like is provided at the center of the opened board. It has a structure.

  Next, a method for manufacturing the image sensor type module will be described. First, as shown in FIG. 6B, wire-like wiring (609) is joined to the outer pad (605) of the flexible substrate I (601) by soldering or the like. Thereafter, the smallest module can be provided by bending the back surface of the semiconductor chip (602) into an L shape and bundling a plurality of wires into a cable shape. However, when the lens unit is rotated 360 degrees, it is conceivable that the flexible film substrate is easily deformed and the circuit is destroyed. For this reason, as shown in FIG. 5, the rigid substrate portion is fixed by joining the outer lead (514) of the substrate I and the inner lead (512) of the rigid rigid substrate II with ACF (510) or the like, so that the film Therefore, a highly reliable cable-shaped image sensor module can be provided.

It is the top view and sectional drawing which show the 1st Example of this invention. (A) It is a top view which shows a 1st Example. (B) It is a bottom view which shows a 1st Example. (C) It is A-A 'sectional drawing in Drawing 1 (A). (D) It is a B-B 'sectional view in Drawing 1 (A). (E) It is the schematic before bending. It is the top view and sectional drawing which show the 2nd Example of this invention. (A) It is a top view which shows a 2nd Example. (B) It is a bottom view which shows a 2nd Example. (C) It is A-A 'sectional drawing in Drawing 2 (A). (D) It is a B-B 'sectional view in Drawing 2 (A). (E) It is the schematic before bending. It is sectional drawing which shows the 3rd Example of this invention. It is sectional drawing which shows the 3rd Example of this invention. It is sectional drawing which shows the 4th Example of this invention. It is sectional drawing which shows the 4th Example of this invention. (A) It is sectional drawing at the time of joining a 2nd board | substrate to the outer pad part of a 1st board | substrate with ACF etc., and joining a wire-like wiring to the outer pad part of a 2nd board | substrate with solder. (B) It is sectional drawing at the time of joining a wire-like wiring to the outer pad part of a 1st board | substrate with solder. It is sectional drawing which shows an example of the past. It is a general camera module and is used for an optical module such as a stomach camera. It is sectional drawing which shows an example of the past. This is a general camera module used for cameras such as mobile phones.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Substrate 102 Semiconductor chip 103 Sensor circuit part 104 Cover glass 105 Glass sealing part 106 Connection sealing part 107 Fixing adhesive 108 Pad electrode 109 Bump 110 Outer pad 111 Outer connection part 201 Substrate 202 Semiconductor chip 203 Sealing resin 204 Connection Sealing part 205 Fixing adhesive 206 Pad electrode 207 Bump 208 Outer pad 209 Outer connection part 301 Substrate 302 Semiconductor chip 303 Interposer 304 Inner pad 305 Outer pad 306 Second outer pad 307 Outer connection part 308 Solder 309 Solder ball 401 Substrate 402 Semiconductor chip 403 Cover glass 404 Glass sealing part 405 Interposer 406 Inner pad 407 Outer connection part 408 Outer pad 40 9 Second outer pad 501 Substrate I
502 Substrate II
503 Semiconductor chip 504 Cover glass 505 Glass sealing part 506 Connection sealing part 507 Pad electrode 508 Bump 509 Resin stop dam 510 ACF
511 Resist 512 Inter lead 513 Inner pad 514 Outer lead 515 Outer connection portion 516 Second outer pad 601 Substrate I
602 Semiconductor chip 603 Cover glass 604 Inner pad 605 Outer pad 606 Outer connection part 607 ACF
608 Second outer pad 609 Cable wiring 610 Substrate II
611 Soldering

Claims (8)

A semiconductor chip with bumps formed on the pad electrode is flip-chip mounted on a substrate having a hole in the center and a circuit pattern formed, and then the junction between the semiconductor chip and the substrate and the side surface of the semiconductor chip A semiconductor package comprising: an outer connecting portion that seals a portion, seals a hole in a central portion of the substrate with a cover glass, and extends one end of the substrate in one direction. The substrate is made of a flexible substrate such as polyimide, the substrate is provided with an outer connection portion having an outer pad, and the outer pad portion is provided with a hole slightly smaller than the outer pad diameter. The semiconductor package according to claim 1, wherein the semiconductor package has a structure in which an outer peripheral portion is bent in a U shape and disposed on the back surface of the semiconductor chip. The said outer connection part was connected to the board | substrate which has the 2nd outer pad part formed with the pitch wider than the pad pitch of the said outer pad part with solder, ACF resin, etc. Semiconductor package. 3. The semiconductor package according to claim 2, wherein the outer connecting portion is connected to a substrate extending in at least one direction having a second outer pad for connecting to the outside by solder, ACF resin or the like. . The semiconductor package according to claim 1, wherein a flexible substrate is used as a substrate on which a circuit pattern is formed, and a wire or the like is attached to the outer pad with solder or the like in a substrate on which an outer connection portion having an outer pad is arranged. A semiconductor package, wherein the flexible substrate is connected and bent to the back side of the semiconductor chip and arranged in an L shape with the semiconductor chip. The semiconductor package according to claim 1, wherein a flexible substrate is used as a substrate on which a circuit pattern is formed, and the outer pad is bonded to a second substrate in a substrate on which an outer connection portion having an outer pad is arranged. Further, a wire or the like is connected to the outer pad of the second substrate with solder or the like, the flexible substrate is bent to the back side of the semiconductor chip, and the second substrate is arranged in an L shape with the semiconductor chip. In addition, an image sensor type module, wherein a lens kit having a cover glass or the like is provided at the center of the opened substrate. 5. The substrate according to claim 1, wherein the substrate has a hole in the central portion of the substrate and the circuit pattern is formed. The hole in the central portion of the substrate is sealed with a resin. The semiconductor package described. A UV curable resin is used as a sealing material for the bonding portion between the semiconductor chip and the substrate, the side surface portion of the semiconductor chip, and the cover glass. The semiconductor package or image sensor type module according to claim 5, claim 6, or claim 7.

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