JP2005327801A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent ultraviolet rays for hardening a sealing agent from entering a light receiving surface and deteriorating characteristics of a solid-state imaging element, and also to prevent the intrusion of a flowed-out sealing agent into the light receiving surface by uniformly irradiating the ultraviolet rays on a portion which needs be irradiated with the ultravilet rays. <P>SOLUTION: Between a package 4 and the emission end 12 of an optical fiber 11, a metallic lightproof mask 10 is formed. In the lightproof mask 10, a plurality of through holes 15 are formed to allow ultraviolet rays to pass through only necessary parts and then incident into the package 4. By changing sizes of the through holes 15 according as the ultraviolet rays are irradiated, a variation in illuminance can be eliminated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a semiconductor device in which a semiconductor element is bonded to a package by an optical reaction.

  A solid-state imaging device is generally used as a device charge-coupled device that converts image incident light into an image electrical signal. This is a semiconductor element in which a sensor unit that converts an optical image formed by an imaging lens into an electrical signal and a circuit unit that processes an electrical signal output from the sensor unit are provided on one silicon substrate. In order to protect this semiconductor element from temperature or humidity changes, a solid-state imaging device is incorporated in a package such as a plastic mold. This solid-state imaging device is mounted on a substrate together with other electronic components, and a product such as a video camera or a digital still camera is completed.

  Hereinafter, a method for attaching a conventional solid-state imaging device to a package will be described with reference to the drawings.

  FIG. 4 is a perspective view for explaining a conventional method, and FIG. 5 is a cross-sectional view for explaining a main part in FIG. 4. First, gold bumps 3 are formed on the electrical connection terminals of the solid-state imaging device 1. In addition, a conductive adhesive 7 is applied to the bumps 3, and the bumps 3 of the solid-state imaging device 1 are electrically connected to the circuit pattern 6 of the package 4.

  Since the adhesive strength of the conductive adhesive 7 is not so high, the gap between the solid-state imaging device 1 and the package 4 is filled with an epoxy resin-based ultraviolet curable sealant 8 to firmly bond them together. The sealant 8 is liquid and is injected into a portion to be filled by using a dispenser nozzle 9 for supplying a certain amount of liquid.

  That is, while discharging the sealant 8 from the dispenser nozzle 9, the movement of the dispenser nozzle 9 is made around the solid-state imaging device 1 by a moving device (not shown), and the entire circumference of the solid-state imaging device 1 and the package 4 are Sealant 8 is injected into the gap.

The package 4 is formed with a rectangular window 5 that is about 0.2 mm larger than the light receiving portion 2 of the solid-state imaging device 1, and an optical fiber 11 is provided below and irradiated with ultraviolet rays from the output end 12 of the optical fiber 11. The sealing agent 16 oozing out from between the solid-state imaging device 1 and the package 4 is cured so that the injected sealing agent 8 does not enter the light receiving portion 2 of the solid-state imaging device 1 (see Patent Document 1). .
JP 2002-184963 A

  The wavelength of ultraviolet rays necessary for curing an ultraviolet curable encapsulant is 365 nm. Generally, when light near this wavelength is irradiated to the light receiving surface beyond an allowable value, pixel defects called white scratches occur. There are things to do.

  In other words, the conventional mounting method has a problem that the ultraviolet light is directly incident on the light receiving surface of the solid-state image pickup device to deteriorate the image quality. In addition, the light receiving surface of the solid-state image sensor is rectangular, and the irradiation range of the light guide is circular.The illuminance varies with the distance from the center.Especially, the corners at the four corners have low illuminance, and the sealant oozes out. When the irradiation power is increased in order to generate or maintain the minimum illuminance, there is a problem that ultraviolet rays are incident on the light receiving surface more than necessary and amplify quality degradation.

  The object of the present invention is to solve the above-mentioned conventional problems, prevent the ultraviolet rays for curing the sealant from entering the light-receiving surface and deteriorating the characteristics of the solid-state imaging device, and make the ultraviolet rays uniform where necessary It is an object of the present invention to provide a method for manufacturing a semiconductor device that can prevent the sealant that has flowed out from entering the light-receiving surface by irradiating the semiconductor device with the semiconductor device.

  In order to solve the above problems, a method of manufacturing a semiconductor device according to the present invention includes a package body having a light receiving opening, and a semiconductor element that has a light receiving portion and is mounted so that the light receiving portion faces the light receiving opening. Is a method of manufacturing a semiconductor device in which an ultraviolet curable sealant applied to the periphery of the light receiving opening is irradiated with ultraviolet light and bonded thereto, and the light source for irradiating ultraviolet light from the light receiving opening side and the package And a light shielding mask disposed between the light source and the light source, the masking opening being provided in the light shielding mask so as to correspond to the outer periphery of the light receiving opening, the inside of the mask opening having a light shielding structure, and the mask The sealing agent is irradiated with ultraviolet light incident from the light source through the opening.

  Here, the light source may be a light source emitted from an optical fiber.

  The mask opening is preferably formed so that the adhesive is irradiated with ultraviolet rays having a predetermined intensity distribution.

  The mask opening is preferably formed so that the sealing agent is evenly irradiated with ultraviolet rays.

  In addition, it is preferable that the mask opening is formed so that the amount of ultraviolet irradiation with respect to the corner of the light receiving opening is increased.

  In addition, the mask opening includes a plurality of openings, and at least two of the plurality of openings are different in size.

  The size of each of the plurality of openings is preferably set so that the adhesive is irradiated with ultraviolet rays having a predetermined intensity distribution.

  In addition, it is preferable that the size of each of the plurality of openings is formed so that the adhesive is evenly irradiated with ultraviolet rays.

  In addition, it is preferable that the size of each of the plurality of openings is formed so that the amount of ultraviolet irradiation with respect to the corner of the opening of the package body is increased.

  The mask opening may be covered with a transparent film.

  By the method described above, the variation in the conventional ultraviolet illuminance intensity can be eliminated by changing the hole size of the mask opening or changing the width of the slit depending on the irradiation location.

  According to the present invention, it is possible to avoid unnecessary ultraviolet rays from irradiating the light receiving surface in the semiconductor element having the light receiving portion by the light shielding mask, and the irradiation intensity can be made constant by the aperture effect of the mask opening. The sealing agent can be effectively prevented from entering the light receiving surface, and the semiconductor element having the light receiving portion can be reliably attached to the package without deteriorating the light receiving characteristics.

  In addition, a simple structure such as a thin metal plate corresponding to the size of the light receiving surface can be used without using an expensive and special light guide configured to irradiate ultraviolet rays only around the light receiving surface as in the past. By exchanging the mask, switching corresponding to the package size can be easily performed, and an inexpensive and flexible semiconductor device manufacturing method can be realized.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view for explaining a method of attaching a solid-state image pickup device according to a first embodiment of the present invention to a package, and FIG. 2 is a plan view of a light shielding mask used in this method. In the following description, members corresponding to those described in FIG. 4 and FIG.

  As shown in FIG. 1, a plurality of bumps 3 serving as terminals for connection to an external circuit are formed of gold balls or the like on a light receiving surface 2 of a solid-state imaging device 1 as a semiconductor element having a light receiving portion.

  The package 4 has a window 5 that is a rectangular light receiving opening larger than the light receiving surface 2 of the solid-state imaging device 1 at the center thereof. The solid-state imaging device 1 is attached to the package 4 with the light receiving surface 2 facing the window 5. The package 4 is provided with a circuit pattern formed of a copper foil or the like at a position corresponding to each of the plurality of bumps 3 of the solid-state imaging device 1.

  When the solid-state imaging device 1 is attached to the package 4, the conductive adhesive 7 is applied to the pad portion 6 (electrically connected portion) at the end of the circuit pattern, and the bumps 3 of the solid-state imaging device 1 are respectively corresponding. Position and attach so as to contact the pad portion 6 of the circuit pattern to be performed. As a result, the solid-state imaging device 1 is temporarily attached to the package 4.

  Next, the sealant 8 is injected into the gap between the outer periphery of the solid-state imaging device 1 and the package 4 using the dispenser nozzle 9. The dispenser nozzle 9 is configured to move along the outer peripheral portion of the solid-state imaging device 1 by an XY moving device (not shown). The sealant 8 is an ultraviolet curable resin that is cured by irradiation with ultraviolet rays.

  In the present example, a light shielding mask 10 made of metal is disposed directly under the package 4, and an output end 12 of the optical fiber 11 is disposed below the light shielding mask 10. A light source 14 (hereinafter referred to as a UV light source) that emits ultraviolet rays is disposed at the incident end 13 of the optical fiber 11.

  Ultraviolet rays from the emission end 12 of the optical fiber 11 selectively pass through a plurality of through holes 15 which are mask openings provided at positions facing the outer peripheral portion of the window 5 of the package 4 in the light shielding mask 10, and are selectively solid-state imaging elements. 1 is irradiated. That is, as shown in FIG. 2, since the ultraviolet light is reflected by the inner portion 10a from the installation portion of the through hole 15 of the light shielding mask 10, the ultraviolet light does not enter the light receiving surface 2, but the window of the package 4 The part between 5 and the solid-state image sensor 1 is irradiated. This illuminance can be controlled by measuring the illuminance distribution irradiated from the exit end 12 of the optical fiber 11 in advance and determining the size of each through hole 15.

  The light emitted from the output end 12 of the optical fiber 11 is not uniform within the surface of the light shielding mask 10 and has an illuminance distribution, and the illuminance of the light decreases as the distance from the output end 12 increases. In order to absorb the variation of the exposure amount due to this, it is possible to adjust the stop by partially changing the size of the through hole 15 which is a mask opening. For example, the amount of ultraviolet irradiation to the sealant 8 can be made uniform by reducing the opening of the through hole 15 at a high illuminance and increasing the opening of the through hole 15 at a corner having a low illuminance.

  Further, since the corner of the solid-state imaging device 1 is likely to accumulate the sealant 8 and tends to be insufficiently cured by ultraviolet rays, the periphery of the solid-state imaging device 1 is particularly increased by increasing the illuminance at the corner. A sufficient degree of curing can be obtained throughout.

  The sealant 8 injected by the dispenser nozzle 9 passes through the gap between the solid-state imaging device 1 and the package 4, and excess sealant 16 flows out in the peripheral direction of the light receiving surface 2. The sealant 16 that has flowed out receives the ultraviolet rays irradiated by the optical fiber 11 and the surface thereof is rapidly cured to lose its fluidity. At this time, the ultraviolet light intensity received by the sealant 16 that has exuded has the same illuminance on all four sides, and the sealant 16 that has exuded from the gap can be instantaneously and uniformly cured.

  FIG. 3 is a plan view of a light shielding mask for explaining the second embodiment of the present invention. In the second example, a slit hole 18 is provided in a portion of the light shielding mask 17 where it is desired to transmit ultraviolet rays. The illuminance is controlled according to the slit width.

  The light emitted from the output end 12 of the optical fiber 11 is not uniform within the surface of the light shielding mask 10 and has an illuminance distribution, and the illuminance of the light decreases as the distance from the output end 12 increases. In order to absorb the variation of the exposure amount due to this, the aperture can be adjusted by partially changing the size of the mask opening.

  For example, the ultraviolet irradiation amount to the sealing agent 8 can be made uniform by narrowing the opening width at a high illuminance and widening the opening width at a corner having a low illuminance.

  Moreover, since the corner | angular part in the solid-state imaging device 1 tends to generate | occur | produce the sealing agent 8, and there exists a tendency for hardening of an ultraviolet-ray to become inadequate, especially by making high the illumination intensity of a corner | angular part, the solid-state imaging device 1 A sufficient degree of curing can be obtained over the entire periphery.

  Further, the mask openings such as the through holes 15 and the slit holes 18 may be covered with a transparent film as long as they transmit a wavelength region necessary for exposure, for example, ultraviolet rays.

  A method of attaching a solid-state image pickup device according to the present invention to a package, and a light-shielding mask used in the method are provided when a solid-state image pickup device is packaged to protect the solid-state image pickup device from temperature, humidity, and other external stresses. This is useful as a means for avoiding ultraviolet light irradiation on the light receiving surface, which is the heart of, and preventing the sealing agent from entering the light receiving surface.

Sectional drawing for demonstrating the method to attach the solid-state image sensor which is 1st Example of this invention to a package. The top view of the light-shielding mask in 1st Example of this invention The top view of the light-shielding mask for demonstrating the 2nd Example of this invention The perspective view for demonstrating the method to attach the conventional solid-state image sensor to a package Sectional drawing for demonstrating the method of attaching the conventional solid-state image sensor to a package

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor 2 Light-receiving surface 3 Bump 4 Package 5 Window 6 Pad part 7 Conductive adhesive 8 Sealant 9 Dispenser nozzle 10, 17 Light-shielding mask 11 Optical fiber 12 Optical fiber exit end 13 Optical fiber incident end 14 Light source 15 Through-hole 16 Sealant that has flowed out 18 Slit hole

Claims (10)

An ultraviolet curable sealant that is applied to the periphery of the light receiving opening, and includes a package body having the light receiving opening and a semiconductor element that has the light receiving part and is mounted so that the light receiving part faces the light receiving opening. A method of manufacturing a semiconductor device that adheres by irradiating with ultraviolet rays,
A light source that emits ultraviolet light from the light receiving opening side;
A light-shielding mask disposed between the package and the light source,
A mask opening is provided in the light shielding mask so as to correspond to the outer peripheral portion of the light receiving opening, a light shielding structure is provided on the inner side of the mask opening, and ultraviolet rays are incident from the light source through the mask opening to thereby apply the sealing agent. Irradiation, a method for manufacturing a semiconductor device.   The method of manufacturing a semiconductor device according to claim 1, wherein a light source emitted from an optical fiber is used as the light source.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the light shielding mask is a mask in which the mask opening is formed so that the sealing agent is irradiated with ultraviolet rays having a predetermined intensity distribution.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the light shielding mask is a mask in which the mask opening is formed so that the sealing agent is evenly irradiated with ultraviolet rays.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the light shielding mask is a mask in which the mask opening is formed so that an amount of ultraviolet irradiation with respect to a corner of the light receiving opening is increased.   The semiconductor device manufacturing method according to claim 1, wherein the mask opening includes a plurality of openings, and at least two of the openings are different in size. Method.   As the light shielding mask, the mask opening includes a plurality of openings, and the sizes of the openings are set so that the sealing agent is irradiated with ultraviolet rays having a predetermined intensity distribution. The method of manufacturing a semiconductor device according to claim 6, wherein:   As the light-shielding mask, a mask having a plurality of openings and the size of each of the plurality of openings being set so that the sealing agent is evenly irradiated with ultraviolet rays is used. The method of manufacturing a semiconductor device according to claim 6, wherein:   As the light-shielding mask, the mask opening is composed of a plurality of openings, and the size of each of the plurality of openings is set so that the amount of ultraviolet irradiation with respect to the corner of the opening of the package body is increased. 7. The method of manufacturing a semiconductor device according to claim 6, wherein the method is used.   The method of manufacturing a semiconductor device according to claim 1, wherein the mask opening is covered with a transparent film.

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