JP4433391B2 - Glass for semiconductor package window, glass window for semiconductor package and semiconductor package - Google Patents

Description

  The present invention relates to a glass for a semiconductor package, a glass window for a semiconductor package, a manufacturing method thereof, and a semiconductor package. More specifically, the present invention relates to a glass provided for a window of a plastic semiconductor package incorporating a solid-state image sensor such as a digital camera or a VTR camera, a glass window for the semiconductor package, for example, a color of an image sensor such as a CCD. The present invention relates to a glass window for a semiconductor package having a near-infrared absorption filter function for correcting sensitivity, a manufacturing method thereof, and a semiconductor package including the glass window, a semiconductor element, and a package for housing the semiconductor element.

  A semiconductor such as a CCD generates a soft error due to α rays emitted from the window glass for a package. Therefore, the amount of radioactive isotopes that emit α rays contained in the window glass for a package must be reduced. As a window material glass for a semiconductor package in which the emission of α rays is suppressed, for example, a window glass for a semiconductor package in which the contents of U and Th are suppressed to 5 ppb or less is disclosed (for example, see Patent Document 1).

  In recent years, with the miniaturization of digital cameras and the widespread use of camera-equipped mobile phones, a high-pixel and small-size imaging system has been demanded. All parts such as lenses, filters and packages are becoming smaller and thinner. Furthermore, not only miniaturization / thinning but also compounding has been proposed. For example, Patent Document 1 discloses a window glass for a semiconductor package that contains CuO and absorbs near-infrared wavelengths in addition to a transparent window glass for a semiconductor package.

  By the way, the glass for windows of the conventional semiconductor package is adapted to the thermal expansion characteristics of ceramic packages such as alumina and has a relatively small expansion coefficient. For this reason, bonding with a plastic package causes warping / deformation of the package and cracking of the glass due to a difference in thermal expansion, which has been an obstacle to reducing the weight of the package using a plastic material.

JP-A-8-306894

  Under such circumstances, the present invention provides a glass for a window that can be suitably attached to a plastic semiconductor package, a glass window for the semiconductor package having various functions, a manufacturing method thereof, and the glass window. An object of the present invention is to provide a provided semiconductor package.

  As a result of intensive studies to achieve the above object, the present inventor has obtained a glass having a specific average linear expansion coefficient, a specific average linear expansion coefficient, and a content of U and Th below a certain value. Glass can be used for the purpose of plastic semiconductor package window glass, and glass window for semiconductor packages made of these glasses, or for semiconductor packages having a lens function and specific spectral transmittance. The present inventors have found that a glass window can meet the above purpose, and have completed the present invention based on this finding.

That is, the present invention
(1) It is used for a window material of a plastic semiconductor package, and has an average linear expansion coefficient at 100 to 300 ° C. of 120 to 180 × 10 ⁻⁷ / ° C., containing Cu and phosphoric acid, and expressed in terms of cation%. P ⁵⁺ 23 to 41%, Al ³⁺ 4 to 16%, Li ⁺ 11 to 40%, Na ⁺ 3 to 13%, R ²⁺ 12 to 53% (R ²⁺ is Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ), Cu ²⁺ 2.6 to 4.7% and a glass for a semiconductor package window (hereinafter referred to as glass 1), which is made of glass containing F ⁻ and O ²⁻ as anionic components. ),
(2) It is used for the window material of a plastic semiconductor package, the average linear expansion coefficient at 100 to 300 ° C. is 120 to 180 × 10 ⁻⁷ / ° C., and the contents of U and Th are each 5 ppb or less, Containing Cu and phosphoric acid, expressed as cation%, P ⁵⁺ 23 to 41%, Al ³⁺ 4 to 16%, Li ⁺ 11 to 40%, Na ⁺ 3 to 13%, R ²⁺ 12 to 53% (R ²⁺ is Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ), Cu ²⁺ 2.6 to 4.7%, and made of glass containing F ⁻ and O ²⁻ as anionic components Glass for window of semiconductor package for element (hereinafter referred to as glass 2),
(3) The window of the semiconductor package according to (1) or (2) above, wherein the wavelength showing a transmittance of 50% is less than 630 nm in the spectral transmittance of 400 to 700 nm converted to a thickness of 0.5 mm Glass for
(4) A glass window for a semiconductor package (hereinafter referred to as a glass window 1) made of the window glass described in any one of the above items (1) to (3),
(5) A glass window for a semiconductor package as described in the above item (4) having a lens function (hereinafter referred to as a glass window 2),
(6) The glass window for semiconductor packages as described in the above item (4) having a flat plate shape (hereinafter referred to as glass window 3),
(7) The glass window for a semiconductor package according to any one of the above items (4) to (6), which is a precision press-molded product, and (8) any of the above items (4) to (7) 2. A semiconductor package in which the glass window for a semiconductor package according to item 1 and an image sensor for receiving light incident from the glass window are attached , wherein the attachment portion of the glass window is made of a plastic material. Semiconductor package,
Is to provide.

  ADVANTAGE OF THE INVENTION According to this invention, the glass for windows of the semiconductor package which can be favorably mounted | worn to a plastic package, the glass window for semiconductor packages, its manufacturing method, and the semiconductor package provided with the said glass window can be provided.

In the present invention, the window glass means glass used as a material of a window attached to the semiconductor package, and the glass window means a glass window attached to the semiconductor package. Window glass is roughly divided into glass 1 and glass 2 as follows.
[Glass 1]
Glass 1 is used for a window material of a semiconductor package made of plastic, and has an average linear expansion coefficient at 100 to 300 ° C. of 120 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., preferably 135 × 10 ^{−7 to} 180 ×. The glass is 10 ⁻⁷ / ° C., more preferably 140 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C.
According to the glass 1, by setting the average linear expansion coefficient within the above range, it is possible to prevent warping / deformation of the package and breakage of the glass even when bonded to a plastic package. Further, it is possible to provide a window that is superior in durability and homogeneity as compared with a plastic window.
The package includes the entire package for housing the semiconductor element, a frame for fixing the window to the semiconductor element, or the frame having a function of sealing the light receiving surface of the semiconductor element using the window. . Hereinafter, the package means the above package.

[Glass 2]
Glass 2 has an average linear expansion coefficient at 100 to 300 ° C. is 120 to 180 × ^{10 -7} / ° C., preferably ^{135 × 10 -7 ~180 × 10 -7} / ℃, more preferably 140 × ¹⁰ -7 to 180 It is * 10 < ^-7 > / (degreeC), Content of U and Th is a glass for windows below 5 ppb, respectively.
According to the glass 2, by setting the average coefficient of linear expansion within the above range, it is possible to prevent warping / deformation of the package and breakage of the glass even when bonded to a plastic package. Furthermore, since the contents of U and Th are both 5 ppb or less, it is possible to provide a semiconductor package free from soft errors due to the emission of α rays from the glass window. Thereby, the glass window can be disposed close to the semiconductor element, and the package can be reduced in size and weight.
As the glass for windows of the semiconductor package of the present invention, those having the characteristics of the glass 1 and the glass 2 are preferable.

In order to give the window glass a high expansion characteristic with an average linear expansion coefficient at 100 to 300 ° C. of 120 to 180 × 10 ⁻⁷ / ° C., alkali metal oxide or fluorine, or both alkali metal oxide and fluorine Is preferably introduced. The amount of alkali metal oxide and fluorine introduced can be determined in consideration of the above expansion coefficient, good weather resistance and the like.

  Whether the weather resistance is good or not can be determined by holding a glass sample whose surface is polished for 1000 hours under the conditions of a temperature of 60 ° C. and a humidity of 80% RH, and then whether or not the polished surface of the sample is altered such as burns. . That is, the glass having good weather resistance does not show surface alteration even after the weather resistance test, and can be sufficiently used as window glass. On the other hand, the surface of other glass samples is altered, so that it cannot be used as window glass. Whether the weather resistance is good or not can also be determined by the change in spectral transmittance before and after the weather resistance test. The maximum value of the spectral transmittance at a wavelength of 400 to 700 nm is compared before and after the test, and if the maximum value of the spectral transmittance after the test is 90% or more of the maximum value of the spectral transmittance before the test, good weather resistance It can be said that it shows sex. When measuring the spectral transmittance, a sample polished so that both surfaces are parallel to each other is used. Since the spectral transmittance includes light loss at the sample surface, the sample surface state before and after the test can be compared.

  As the window glass, glass having a glass transition temperature of 550 ° C. or lower is preferable. According to such a glass having a low transition temperature, a glass window can be produced by precision press molding. Precision press-molding produces a light entrance / exit surface of the glass window in the shape of a lens, or a pattern for imparting a function as a diffraction grating to the light entrance / exit surface or a pattern for imparting a function as an optical low-pass filter. It can be formed with good properties.

From the viewpoint of glass composition, as the window glass, phosphoric acid-containing glass (for example, fluorophosphate glass or phosphate glass), glass containing SiO ₂ and alkali metal oxide is suitable. According to these glasses, it is easy to obtain a homogeneous glass. As the window glass, fluorophosphate glass is particularly preferable.
Phosphoric acid-containing glass (fluorophosphate glass, phosphate glass) is a glass containing phosphoric acid as a main component, and a specific description thereof will be described later.

As the glass containing SiO ₂ and alkali metal oxide, glass containing SiO ₂ , TiO ₂ , and alkali metal oxide is preferable. As a specific composition, SiO ₂ , TiO ₂ , an alkali metal oxide as essential components, and a glass in which the total amount of the essential components is 60 mol% or more is preferable, and SiO ₂ 38 to 58% in terms of mol%. Further, a glass containing 7 to 30% of TiO ₂ , 15 to 40% in total of alkali metal oxides, and 0 to 12% of Al ₂ O ₃ is more preferable. Among them, Na ₂ O 10-25%, K ₂ O 4-15%, MgO 0-13%, CaO 0-10%, SrO 0-8%, BaO 0-6%, ZnO 0-10%, Sb ₂ Those containing O _{3 from} 0 to 1% are more preferred, and those having an MgO content of from 1 to 13% and a ZnO content of from 0.5 to 10% are particularly preferred. In the above composition range, an optical constant having a refractive index (nd) of around 1.6 and an Abbe number (νd) of around 36 to 37 can be obtained.
Note that both alkali metal oxides and fluorine have a function of increasing the expansion coefficient, but phosphoric acid-containing glasses (fluorophosphate glass and phosphate glass) are more preferable from the viewpoint of hardly adversely affecting the weather resistance. Such glass will be described in detail later.

  In order to impart the color correction filter function of the semiconductor image sensor to the glass for windows, it is preferable to introduce Cu into the glass to have near infrared absorption characteristics. As such window glass with a color correction filter function, it is preferable to use glass containing Cu and phosphoric acid (fluorophosphate glass or phosphate glass), and has a wavelength of 400 to 700 nm converted to a thickness of 0.5 mm. In terms of transmittance, it is more preferable to use a glass having a wavelength of 50% less than 630 nm.

Furthermore, it is important that the glass for windows is arranged close to the semiconductor image pickup device, and that the size and the amount of platinum foreign matter in the glass are suppressed to a level lower than that of normal optical glass. The reason is that if there is a foreign matter such as platinum particles in the window glass, the shadow will appear on the image sensor, or the image may be blurred due to diffraction by the foreign matter. Although glass foreign optical elements such as lenses are generally used to manage foreign substances, these optical elements are used away from the image sensor, so that image quality deterioration due to reflections and diffraction of foreign substances is not caused as much as window material glass. In the window glass of the present invention, the number of platinum particles having a particle diameter of 2 μm or more is preferably 10/100 ml or less, and more preferably not containing platinum particles having a particle diameter of 2 μm or more. In addition, it is preferable from the viewpoint of reducing the amount of radioactive substances such as U and Th to prevent contamination with platinum foreign matter.
Moreover, when not only platinum foreign substances but Cu is introduced, it is desirable not to deposit Cu metal particles or Cu compound particles. The window glass is preferably made of an amorphous phase.

Next, the composition of glass particularly suitable as Cu-containing glass will be described. Its composition is expressed in terms of cation%, P ⁵⁺ 23 to 41%, Al ³⁺ 4 to 16%, Li ⁺ 11 to 40%, Na ⁺ 3 to 13%, R ²⁺ 12 to 53% (R ²⁺ is Mg ²⁺ , Examples include Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ), Cu ²⁺ 2.6 to 4.7%, and F ⁻ and O ²⁻ as anionic components. Hereinafter, the cation ratio is expressed as cation%, and the anion ratio is expressed as anion%.

P ⁵⁺ is a basic component of fluorophosphate glass and an important component that brings about absorption in the infrared region. If it is less than 23%, the color may be deteriorated and greenish. On the contrary, if it exceeds 41%, the weather resistance and devitrification resistance tend to deteriorate. Therefore, the content of P ⁵⁺ is preferably 23 to 41%.

Al ³⁺ is an important component that improves the devitrification resistance of fluorophosphate glass. If it is less than 4%, the devitrification resistance is poor, and the liquidus temperature becomes high, which may make it difficult to melt and mold high-quality glass. Conversely, even if it exceeds 16%, devitrification resistance may deteriorate. Therefore, the content of Al ³⁺ is preferably 4 to 16%.

Li ⁺ is a useful component that improves the devitrification resistance of the glass, but if it is less than 11%, its effect is insufficient, and if it exceeds 40%, the durability and workability of the glass may deteriorate. . Therefore, the content of Li ⁺ is preferably 11 to 40%.

Na ^{+ is} also a useful component for improving the devitrification resistance of the glass, but if it is less than 3%, its effect is insufficient, and conversely if it exceeds 13%, the durability and workability of the glass may deteriorate. . Therefore, the content of Na ⁺ is preferably 3 to 13%.

R ²⁺ (Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ) is a useful component that improves the devitrification resistance, durability, and workability of glass in fluorophosphate glass. If the total of R ²⁺ is less than 12%, the devitrification resistance and durability of the glass are likely to deteriorate, whereas if it exceeds 53%, the devitrification resistance may be deteriorated. Therefore, the content of R ²⁺ is preferably 12 to 53%.

The preferable range of Mg ²⁺ is 3 to 5%, the preferable range of Ca ²⁺ is 6 to 9%, the preferable range of Sr ²⁺ is 5 to 8%, the preferable range of Ba ²⁺ is 3 to 6%, and the preferable range of Zn ²⁺ The range is 0 to 3%.

When Cu ²⁺ is less than 2.6%, infrared absorption is small, and in the range where the transmittance converted to a thickness of 0.5 mm is 400 to 700 nm, the wavelength at which the transmittance is 50% may be longer than 630 nm. . On the other hand, if it exceeds 4.7%, the devitrification resistance is deteriorated. Therefore, the content of Cu ²⁺ is preferably 2.6 to 4.7%.

O ²⁻ is an anion component that is particularly important in the window glass. If it is less than 52%, divalent Cu ²⁺ is reduced to monovalent Cu ⁺ , so that absorption tends to increase in the short wavelength region, particularly in the vicinity of 400 nm, and a green color is exhibited. Therefore, the content of O ²⁻ is preferably 52 to 75%.

F ⁻ is an important anion component that lowers the melting point of the glass and improves the weather resistance. When the window glass contains F ⁻ , the melting temperature of the glass can be lowered, and the amounts of U, Th, and platinum foreign matter entering from the furnace wall, the refractory, and the heat-resistant container during melting can be easily suppressed. If it is less than 25%, the weather resistance is insufficient. Conversely, if it exceeds 48%, the content of O ²⁻ decreases, which causes coloration around 400 nm with monovalent Cu ⁺ . Therefore, the content of F ⁻ is preferably 25 to 48%.

K ⁺ , Zr ⁴⁺ , La ³⁺ , Gd ³⁺ , Y ³⁺ , Si ⁴⁺ , B ³⁺ , Sb ³⁺ , Ce ⁴⁺ are used appropriately for the purpose of improving devitrification resistance, adjusting glass viscosity, adjusting transmittance, and clarifying. However, the total amount of the cations is preferably less than 5%, more preferably less than 1%, and even more preferably not introduced.

In addition, the preferable composition range in the said composition range is shown below.
(Preferred range 1)
As an anion ^{component, P 5+ 23~41%, Al 3+} 4~16%, Li + 11~40%, Na + 3~13%, R 2+ 12~53% (R 2+ is ^{Mg 2+,} Ca 2+, ^{Sr 2+ , Ba 2+, Zn 2+),} Cu 2+ 2.6~4.7%, F as an anion component - from 25 to 48% and ^O 2-52-75% fluorophosphate glass containing.
(Preferred range 2)
A total amount of P ⁵⁺ , Al ³⁺ , Li ⁺ , Na ⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ , Cu ²⁺ , Sb ³⁺ is 99 cation% or more, more preferably 100 cation% fluorophosphate Glass.
(Preferable range 3)
A fluorophosphate glass having a total amount of F ⁻ and O ²⁻ of 100 anion%.
(Preferred composition range 4)
A fluorophosphate glass containing no Pb, As, or Cd. In addition, the glass which does not contain Pb, As, and Cd is preferable not only for fluorophosphate glass but in any of window material glasses 1-3.

According to the fluorophosphate glass, an optical constant having a refractive index (nd) of about 1.5 and an Abbe number (νd) of about 74.5 can be obtained. Therefore, in designing the lens shape, the optical constant may be referred to.
Phosphoric acid-containing glass such as phosphate glass or fluorophosphate glass is generally poor in chemical durability, and cannot withstand, for example, a weather resistance test for 1000 hours in an environment of 60 ° C. and 80% RH. The above glass is excellent in chemical durability, withstands a weather resistance test held for 1000 hours in an environment of 60 ° C. and 80% RH, and is sufficiently used as window glass. Possible surface condition can be kept.

Next, the manufacturing method of the glass for windows is demonstrated.
As a glass raw material for window glass, it is desirable to use a raw material having a U and Th content of 1 ppb or less. For example, using raw materials such as phosphates, fluorides, carbonates, nitrates and oxides as appropriate, the raw materials are weighed and mixed so as to have a desired composition, and then heated to, for example, 800 to 900 ° C. using a heat-resistant crucible. Dissolve. The material of the heat-resistant crucible is preferably quartz or platinum having a very small U and Th content. Particularly preferably, the raw material is roughly dissolved in a quartz crucible and then melted in a platinum crucible. Thereby, generation | occurrence | production of a platinum foreign material is suppressed. When melting fluorine-containing glass, it is desirable to use a heat-resistant lid such as quartz or platinum in order to suppress volatilization of the fluorine component. Further, although there is no problem in the melting atmosphere in the air, in the case of a Cu-containing window glass, it is preferable to use an oxygen atmosphere or to bubble oxygen into the molten glass in order to suppress changes in Cu valence. In order to suppress intrusion of U, Th, and platinum foreign matter from the furnace wall, refractory, melting crucible, etc., the melting temperature is preferably lower. After the molten glass is stirred and clarified, the glass is poured out to form a window glass.

Conventionally used methods such as casting, pipe outflow, roll, and press can be used as a method for forming window glass, but large and thick glass forming is particularly preferable. The formed glass material is transferred to an annealing furnace that has been heated in the vicinity of the glass transition point in advance and gradually cooled to room temperature.
The obtained glass material is subjected to accurate slicing, grinding, and polishing to form a glass window.

Next, a glass window for a semiconductor package will be described. The glass window of the present invention is roughly divided into a glass window 1 to a glass window 3.
[Glass window 1]
The glass window 1 is made of any of the above glass for windows. By providing a glass window with the glass for the window, a glass window that can be attached to a package, prevent the influence of radiation, and provide a near-infrared absorbing function by utilizing the characteristics of each glass is provided. Can do.

[Glass window 2]
The glass window 2 has a lens function, and an average linear expansion coefficient at 100 to 300 ° C. is 120 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., preferably 135 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C. more preferably characterized in that it is a ^{140 × 10 -7 ~180 × 10 -7} / ℃.
According to the glass window 2, even if it adheres to a plastic package, it is possible to prevent warping / deformation of the package and breakage of the glass. Further, since the lens function is provided, a part or all of the imaging optical system that forms an image on the light receiving surface of the semiconductor imaging device that accommodates the light transmitted through the glass window in the package can be configured by the glass window. Therefore, the number of parts can be reduced, and a decrease in the amount of light to be detected on the light receiving surface of the semiconductor image sensor can be prevented.
The lens function is given by forming the glass window into a lens shape, for example, a convex meniscus lens, a concave meniscus lens, a plano-convex lens, a plano-concave lens, or by forming a diffraction pattern on the surface of the window glass. Or by forming a refractive index distribution.

[Glass window 3]
Glass window 3 has an average linear expansion coefficient at 100 to 300 ° C. is 120 to 180 × ^{10 -7} / ° C., preferably ^{135 × 10 -7 ~180 × 10 -7} / ℃, more preferably 140 × ^{10 -7} ~ 180 × 10 ⁻⁷ / ° C., U and Th contents are both 5 ppb or less, made of glass containing Cu and phosphoric acid, and transmitted at a spectral transmittance of a wavelength of 400 to 700 nm converted to a thickness of 0.5 mm. This is a flat glass window for a semiconductor package whose wavelength showing a rate of 50% is less than 630 nm. Examples of the glass containing Cu and phosphoric acid include Cu-containing fluorophosphate glass and Cu-containing phosphate glass. Cu-containing fluorophosphate glass is more suitable.

  By containing Cu, the glass window 3 imparts near-infrared absorption characteristics and the above-described spectral transmittance characteristics, and expresses the color correction filter function of the semiconductor imaging device. Another feature is that it has a flat plate shape. Because of the above spectral transmittance characteristics, the semiconductor image sensor functions as a sufficient color correction filter even if it is thinned. Furthermore, since it has the above thermal expansion characteristics, even if it is bonded to a plastic package with a thin plate, it does not generate warpage, deformation, or glass breakage, which is suitable for making a glass window thinner and smaller and lighter.

In the flat shape of the glass window 3, as well as the glass window 1 and the glass window 2, the plate thickness is preferably 0.1 to 0.8 mm, and more preferably 0.3 to 0.6 mm.
The glass window for a semiconductor package of the present invention has the characteristics of the glass window 1 and the glass window 2, the characteristics of the glass window 1 and the glass window 3, and the characteristics of the glass window 2 and the glass window 3. What combines the characteristics of the glass windows 1 to 3 is preferable.

Next, common points of the glass windows 1 to 3 will be described.
The glass window is preferably a precision press-molded product. A precision press-molded product is a glass molded product produced by precision press-molding glass in a plastically deformable state. Precision press-molding is a precise transfer of the molding surface of a press mold to the glass. Thus, a molding method for producing an optical functional surface. The optical function surface is a surface used for reflecting, refracting, diffracting, or transmitting a light beam as a control object, and corresponds to a light incident / exit surface of a glass window. According to the precision press molding, a sufficient function can be obtained without performing machining such as grinding or polishing on the optical functional surface. Precision press-molded products include glass windows that also serve as aspherical lenses such as convex meniscus lenses, concave meniscus lenses, plano-convex lenses, and plano-concave lenses, and glass that also serve as spherical lenses such as convex meniscus lenses, concave meniscus lenses, plano-convex lenses, and plano-concave lenses. In addition to a window, a glass window also serving as a Fresnel lens, and a glass window having a pattern having a low-pass filter function formed on the surface thereof, a flat glass window may be used.

Each glass window is suitable as a glass window of a plastic package. Although there is no restriction | limiting in particular as a material of a plastic package, The epoxy resin etc. which contained the glass filler can be illustrated as what can perform favorable packaging. Details of the package material will be described later.
The glass composition suitable for the glass windows 1 to 3 is common to that suitable for the window glass. The same applies to the point that Cu is introduced when the near-infrared absorption property is imparted, and that phosphoric acid glass or fluorophosphate glass is suitable when Cu is introduced.

  In the glass window 3, as described above, the U and Th contents are 5 ppb or less, preferably 3 ppb or less. However, the U and Th contents in the glass windows 1 and 2 are also 5 ppb or less. Is preferable, and 3 ppb or less is more preferable. By using such a glass window, it is possible to provide a semiconductor package free from soft errors due to emission of α rays from the glass window. Thereby, the glass window can be disposed close to the semiconductor element, and the package can be reduced in size and weight. By making the contents of U and Th extremely low as described above, it is possible to prevent the occurrence of a soft error even when a semiconductor image pickup device having a large number of pixels is used. The above package is suitable for a semiconductor package containing an image pickup device having a pixel count of 1 million pixels or more, suitable for a semiconductor package containing an image pickup device of 1.5 million pixels or more, and containing an image pickup device of 2 million pixels or more. It is further suitable for a semiconductor package.

Next, the manufacturing method of the glass window for semiconductor packages by the precision press molding of this invention is demonstrated. In the above method, the average linear expansion coefficient at 100 to 300 ° C. is 120 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., preferably 135 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., and more preferably 140 × 10. ^A lens-shaped window material glass made of ^{-7 to} 180 × 10 ⁻⁷ / ° C. glass is precision press-molded.

In this method, first, a preform having a weight equal to the weight of the press-formed product is formed. For preform molding, a glass block obtained by molding molten glass is machined to a predetermined weight, or a predetermined weight of molten glass is molded into a preform shape while the glass is in a softened state. Can be used. A thin film may be appropriately formed on the preform surface so that good precision press moldability can be obtained. Next, the preform is reheated and precision press-molded using a press mold. The molding surface of the press mold is precisely processed into a shape obtained by inverting the shape of the lens surface, and the shape of the molding surface is precisely transferred to glass by press molding, and a lens-shaped precision press-molded product can be obtained. The precision press molding is desirably performed in a non-oxidizing atmosphere such as nitrogen or a mixed gas of nitrogen and hydrogen. As the press mold, a mold such as cemented carbide or SiC, or a mold provided with a release film such as a carbon film or a noble metal alloy film on the molding surface can be used. A known method may be used for reheating, pressing, and cooling of the precision press-molded product, and the conditions of each process may be set appropriately according to the shape and size of the precision press-molded product.
In this way, the glass window can be formed. The precision press-molded product may be centered as necessary, or may be provided with an antireflection film on the optical function surface. Moreover, you may provide the pattern which expresses an optical low-pass filter function on the surface of a glass window with precision press molding with a lens shape.

Next, the semiconductor package of the present invention will be described. A semiconductor package according to the present invention includes a glass window produced by the manufacturing method using the glass window or the precision press molding, a semiconductor element that receives light incident from the glass window, and a plastic package that houses the semiconductor element. It is characterized by providing. The semiconductor element is preferably a solid-state imaging element such as a CCD or CMOS. The package may be entirely made of plastic, but at least the mounting portion of the glass window is made of a plastic material.
The above package is a package for housing a semiconductor element, a member for covering the light receiving portion of the semiconductor element with a glass window, a frame for fixing the glass window to the semiconductor element, or a light receiving portion of the semiconductor element with the glass window. The frame body having a function of sealing is also included.

The material for the plastic package is not particularly limited, and various materials can be used. Specifically, thermosetting such as epoxy resin (bisphenol A type epoxy resin, novolac type epoxy resin, glycidylamine type epoxy resin, etc.), polyimide resin, phenolic resin, unsaturated polyester resin, silicone resin, etc. A thermoplastic resin such as a resin, a liquid crystal polymer, a polyphenylene sulfide resin, or a polysulfone resin can be used. In addition, a curing agent, a curing accelerator, a hygroscopic agent, a filler, a flame retardant, a pigment, a release agent, and an inorganic filler can be blended with these resins. Among these, an epoxy-based resin containing a glass filler can be cited as one that can be satisfactorily packaged. Moreover, there is no restriction | limiting in particular as the attachment method to the package of a glass window, The adhesion | attachment using an ultraviolet curable resin etc. can be illustrated.
According to the semiconductor package described above, the matching of the thermal expansion characteristics of the glass window and the package or the glass window mounting portion of the package can prevent the warpage / deformation of the package and the breakage of the glass even if the package and the glass window are bonded. .

Further, even when the glass window is thinned, it is possible to prevent the glass from being warped or broken. Also. Even if a glass window having a lens function is used, the glass window is not distorted, so that good imaging performance can be obtained.
Furthermore, by using a Cu-containing glass for the glass window, the glass window fulfills a color correction filter function, so the number of parts can be reduced. Similarly, the number of parts can be reduced by providing a lens function to the glass window, or by providing the lens function and the color correction filter function, and the apparatus can be reduced in size and weight.

In addition, it is desirable to pay sufficient attention to the contamination of radioactive materials in the packaging material as well as the window material glass.
In addition to the glass window, an optical system for forming an image of a subject can be attached to the light receiving unit of the semiconductor image sensor. These optical systems are composed of one or a plurality of lenses, and depending on whether or not the glass window has a lens function, a lens shape in the case of using a material having desired optical characteristics by a known optical design method, It is good to decide the lens arrangement. A diaphragm can be added to the optical system as necessary. Further, it is preferable to use a glass material as the window material as the lens constituting the optical system. The average linear expansion coefficient at 100 to 300 ° C. is 120 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., preferably 135 × 10 ^{−7 to} 180 × 10 ⁻⁷ / ° C., more preferably 140 × 10 ^−7. A glass of ˜180 × 10 ⁻⁷ / ° C. is preferred. Furthermore, a glass containing phosphoric acid-containing glass (phosphate glass or fluorophosphate glass), SiO ₂ and an alkali metal oxide, and having a glass transition temperature of 600 ° C. or lower is preferable.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

Examples 1-6
The raw materials such as phosphates, fluorides, carbonates, nitrates and oxides were weighed appropriately and mixed so as to have the compositions shown in Tables 1 and 2, and then dissolved in a platinum crucible. The glass of Examples 1-5 melt | dissolved at 800-900 degreeC, and the glass of Example 6 melt | dissolved at 1300 degreeC. Note that Cu was not introduced into the glass of Example 6.
After the glass was stirred and clarified, it was poured out into an iron plate shape, and glass blocks having the compositions shown in Tables 1 and 2 were formed. The glass block was transferred to a furnace heated near the glass transition point and annealed to room temperature. Samples for various measurements were cut out from the obtained glass block, and various properties were determined as follows. The results are shown in Tables 1 and 2.
(1) Average linear expansion coefficient The average linear expansion coefficient in 100-300 degreeC was measured based on Japan Optical Glass Industry Association standard JOGIS-08.
(2) Spectral transmittance Spectral transmittance was measured with a spectrophotometer on a plate glass sample having a thickness of 0.5 mm polished on both sides parallel to each other, and each parameter was calculated. Since each glass is homogeneous, the transmittance at an arbitrary thickness can be calculated by a known method based on the transmittance measured with a sample having a thickness of 0.5 mm. The spectral transmittance includes the reflection loss on the sample surface.
(3) U and Th contents The contents of U and Th were measured using an ICP mass spectrometer.
(4) Weather resistance After the weather resistance test was conducted for 1000 hours on a polished sample under the conditions of a temperature of 60 ° C. and a humidity of 80% RH, the surface was observed to evaluate the weather resistance.
(5) Number Density of Platinum Foreign Objects The sample was enlarged and observed using an optical microscope, the number of mixed particles having a particle diameter of 2 μm or more was counted, and the number density was determined from the number of counted foreign substances and the volume of the observation region.

各実施例のガラスとも、１００〜３００℃における平均線膨張係数は１４０〜１８０×１０^−７／℃の範囲にあり、ＵおよびＴｈの含有量はともに５ｐｐｂ未満である。また、白金異物を含め、粒子径２μｍ以上の異物は認められなかった。さらに、Ｃｕ金属粒子、Ｃｕ化合物粒子、結晶相なども認められなかった。
耐候性試験の結果、各実施例のガラスともヤケなどの表面変質は認められなかった。また、試験後の分光透過率の最大値は、試験前における分光透過率の最大値の９０％よりも大きい値を保っていた。
実施例１〜５のガラスについては、厚さ０．５ｍｍに換算した波長４００〜７００ｎｍの分光透過率において、透過率５０％を示す波長は６３０ｎｍ未満であった。

The glass of each Example has an average linear expansion coefficient at 100 to 300 ° C. in the range of 140 to 180 × 10 ⁻⁷ / ° C., and the contents of U and Th are both less than 5 ppb. Further, no foreign matter having a particle diameter of 2 μm or more was observed including platinum foreign matter. Further, Cu metal particles, Cu compound particles, crystal phases and the like were not observed.
As a result of the weather resistance test, no surface alteration such as discoloration was observed in the glass of each example. Further, the maximum value of the spectral transmittance after the test was maintained at a value larger than 90% of the maximum value of the spectral transmittance before the test.
About the glass of Examples 1-5, the wavelength which shows the transmittance | permeability 50% was less than 630 nm in the spectral transmittance of wavelength 400-700 nm converted into thickness 0.5mm.

Example 7
The glass of Example 1 was bonded to a plastic package containing a CCD with 2 million effective pixels using an ultraviolet curable resin to produce a semiconductor package. The material of the package was an epoxy resin containing a glass filler, and the thermal expansion coefficient was 150 × 10 ⁻⁷ / ° C. The semiconductor package to which the window glass was adhered was subjected to a thermal cycle test at -40 ° C to + 120 ° C. When the state of the glass after 100 cycles was observed, no damage was observed in any of the window glass, the package, and the bonded portion. When an optical system is arranged to form an image on the CCD light-receiving surface in the semiconductor package and the image taken with the CCD is observed, no soft error is observed, and faithful color reproduction is achieved by good color correction. It was confirmed that good image quality was obtained. In addition, the same favorable result was obtained even if it used the window material glass of Examples 2-5. Further, since the window glass of Example 6 does not contain Cu, it does not have a color correction filter function, but was a favorable glass window for semiconductor packages.
Further, for each of the glasses obtained in Examples 1 to 6, the same method as described above except that a plastic package (material is the same as the above material) containing a CMOS image sensor is used instead of the CCD built-in plastic package. Was repeated to produce a semiconductor package, and good results were obtained as in the case of the CCD built-in package.
As a specific example of such a semiconductor package, a digital camera incorporating a semiconductor imaging device such as a CCD or CMOS, a mobile phone with a camera incorporating a semiconductor imaging device such as a CCD or CMOS, and the like can be shown.

Example 8
Preforms made of the respective glasses of Examples 1 to 6 were molded, the preforms were reheated, and an aspheric lens was produced by precision press molding. This aspheric lens was used as a glass window to be bonded and fixed to the CCD built-in package used in Example 6 to produce a semiconductor package. Next, when an image forming optical system including the glass window was constructed to form a subject image on the CCD light receiving surface and the image was observed, a good image quality could be obtained. In addition, when each glass of Examples 1 to 5 is used, good color reproduction can be realized without using a separate color correction filter having near infrared absorption characteristics. According to this embodiment, the number of parts can be reduced by using a glass window as a lens.
Further, for each of the glasses obtained in Examples 1 to 6, the same method as described above except that a plastic package (material is the same as the above material) containing a CMOS image sensor is used instead of the CCD built-in plastic package. Was repeated to produce a semiconductor package, and good results were obtained as in the case of the CCD built-in package.
As a specific example of such a semiconductor package, as in the seventh embodiment, a digital camera incorporating a semiconductor image pickup device such as a CCD or CMOS, a mobile phone with a camera incorporating a semiconductor image pickup device such as a CCD or CMOS, and the like. Can show.

The glass window for a semiconductor package of the present invention reduces soft errors due to α-ray emission, and can effectively prevent warpage / deformation of the package and cracking of the glass due to a difference in thermal expansion from the plastic package. It can be suitably used for a package.

Claims (8)

It is used for a window material of a plastic semiconductor package, has an average coefficient of linear expansion at 100 to 300 ° C. of 120 to 180 × 10 ⁻⁷ / ° C., contains Cu and phosphoric acid, and indicates P ⁵⁺ 23 in terms of cation%. ~ 41%, Al ³⁺ 4-16%, Li ⁺ 11-40%, Na ⁺ 3-13%, R ²⁺ 12-53% (R ²⁺ is Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ) , Cu ²⁺ 2.6 to 4.7%, and made of glass containing F ⁻ and O ²⁻ as anionic components. Provided for window material of plastic semiconductor package, average linear expansion coefficient at 100 to 300 ° C. is 120 to 180 × 10 ⁻⁷ / ° C., U and Th contents are each 5 ppb or less, and Cu and phosphoric acid P ⁵⁺ 23-41%, Al ³⁺ 4-16%, Li ⁺ 11-40%, Na ⁺ 3-13%, R2 ⁺ 12-53% (R2 ⁺ is Mg2 ⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Zn ²⁺ ), Cu ²⁺ 2.6 to 4.7%, and made of glass containing F ⁻ and O ²⁻ as anion components. Glass for semiconductor package windows. 3. The glass for a semiconductor package window according to claim 1, wherein a wavelength exhibiting a transmittance of 50% is less than 630 nm in a spectral transmittance of a wavelength of 400 to 700 nm converted to a thickness of 0.5 mm. The glass window for semiconductor packages which consists of the glass for windows of any one of Claims 1-3. The glass window for semiconductor packages of Claim 4 provided with a lens function. The glass window for a semiconductor package according to claim 4, which has a flat plate shape. The glass window for a semiconductor package according to any one of claims 4 to 6, which is a precision press-molded product. A semiconductor package in which the glass window for a semiconductor package according to any one of claims 4 to 7 and an image sensor for receiving light incident from the glass window are attached, and a mounting portion of the glass window is made of plastic. A semiconductor package made of a material.