JP2005050861A - Package lid for semiconductor element and semiconductor element package using the same - Google Patents

Abstract

In a semiconductor package, there is obtained a semiconductor package which is excellent in reliability and transmission characteristics by reducing leakage failure during hermetic sealing and suppressing cavity resonance and feedback oscillation.
In a lid that forms a hermetically sealed package that houses a semiconductor element in combination with a package base, a warp t1 in a long side direction L1 and a warp t2 in a short side direction when the lid 10 is viewed in plan view. Are both convex in the same direction, and the warp rate of the long side is 0.1 to 1.0%.
[Selection] Figure 1

Description

【００７９】
上記実験の結果、表１に示すように、本発明の実施例である試料３、５、７、９、１１、１３〜１５、１７〜２５は、パッケージ組立工程における２００℃、２４時間の乾燥処理後であっても、反りの方向、反り率の変化が少なく、組立後のＨｅリーク試験においてもリーク不良率が極めて小さかったのに対し、比較例である試料１、２、４、６、８、１０、１３は、２００℃、２４時間の乾燥のための熱処理によって、反り率が増加したり、長辺と短辺の反りの方向が違う歪みの反りが発生し、その結果、蓋体の角部においてパッケージベースとの密着が悪くなり、組立後のＨｅリーク試験においてリーク不良率が高い結果となった。
【００８０】
また、本発明の実施例である、蓋体の長辺、短辺の反りが共にパッケージ内側に凸になっている試料１７では、同じく蓋体角部でのパッケージベースとの密着が悪くなり、組立後のＨｅリーク試験においてリーク不良率が高い結果となった。
【００８１】
また、本発明の実施例である反り率が０．１〜１．０％の大きさである試料５、７、９、１４、１５、１７、２０〜２２、２４、２５は、比較例である反り率が０．１未満および反り率が１．０％を超える大きさである試料３、１３、１８、１９、２３と比較して、パッケージ組立後のＨｅリーク試験における歩留まりが良好であることが確認された。
【００８２】
さらに、付加部材として電波吸収体を使用した試料２４、２５では、パッケージ組み立て工程における２００℃、２４時間の乾燥処理後においても、歪みの発生や反り率の増加が見られず、リーク不良率が０％であると同時に、４０ＧＨｚまでの範囲で空洞共振を抑制する効果が確認された。
【００８３】
上記の一連の実験結果によると、本発明の請求範囲の半導体パッケージ用蓋体１を用いれば、気密性に優れ、高信頼性であり、かつ、高周波での伝送特性に優れたパッケージ２０を製造することが可能となることが確認された。
【００８４】
【発明の効果】
以上詳述した通り、本発明によれば、パッケージベースと組み合わせて半導体素子を収納する半導体素子用パッケージ蓋体において、該蓋体を平面視したときの長辺と短辺の反りが共に同一方向に凸であり、長辺の反り率を０．１〜１．０％とすることで、気密封止性に優れた高信頼性の半導体素子用パッケージを得ることが可能となる。
【００８５】
そして、前記半導体素子用パッケージ蓋体を、金属製の基材と、該基材の主表面の少なくとも一方に線膨張係数の異なる付加部材を取着することによって、容易に反りの方向を揃えることができるようになり、線膨張係数の違う付加部材を適宜選択することによって、反りの大きさを変えることを可能とし、長辺と短辺の反りを同一方向に凸とすることができるとともに反り率を調整できる。
【００８６】
さらに、蓋体の内面側に電波吸収体を取着した構成とすれば、気密封止性に優れると同時に、高周波での伝送特性にも優れた半導体パッケージを得ることができる。
【図面の簡単な説明】
【図１】（ａ）は本発明の半導体素子用パッケージ蓋体の斜視図であり、（ｂ），（ｃ）は本発明の半導体素子用パッケージ蓋体の他の一例を示す断面図である。
【図２】本発明の半導体素子用パッケージの断面図および、伝送特性の測定方法を示した概略図である。
【図３】（ａ）、（ｂ）は従来の半導体素子用パッケージ蓋体の斜視図である。
【図４】従来の半導体素子用パッケージの断面図である。
【図５】従来の半導体素子用パッケージの組み立て工程を示した概略図である。
【符号の説明】
１，３１，３２・・・・基材
１ａ，１ｂ・・・面
２，３・・・・・付加部材
１０，３０・・・半導体素子用パッケージ蓋体
２０，４０・・・半導体素子パッケージ
２１，４１・・・パッケージベース
２２，４２・・・回路基板
２３，４３・・・半導体素子
２４，４４・・・伝送線路
２５，４５・・・端子電極
２６，２７，２８，２９・・・ボンディングワイヤ
１５，５０・・・内部空間
４６，４７，４８，４９・・・ボンディングワイヤ
５１・・・台板
５２・・・ローラー部
２００・・・伝送特性測定装置
２０１・・・ネットワークアナライザー
２０２・・・ポート１
２０３・・・ポート２[0001]
BACKGROUND OF THE INVENTION
The present invention particularly relates to a high-frequency circuit device used for high-speed information communication equipment and measurement equipment such as wireless communication and optical communication, a semiconductor device package lid used for an optical device and the like, and a semiconductor device using the same It is about the package.
[0002]
[Prior art]
In semiconductor element packages (hereinafter simply referred to as packages) used for high-frequency circuit devices and optical element devices, semiconductor element package lids (hereinafter simply referred to as lid bodies) made of metal or ceramics are referred to as metals or ceramics. The semiconductor element and the optical element housed in the interior are protected by airtight sealing by attaching to a package base made of, etc., and reliability is ensured.
[0003]
Especially in high-speed and high-capacity high-frequency circuit devices for optical communications and optical element devices, which have been widely used in recent years, the periphery of a lid made of a thin metal plate is seam welded to a metal package base containing a circuit board made of ceramics. What was joined is generally used.
[0004]
In general, these lids are made by processing a metal thin plate into a predetermined shape by a method such as pressing or etching, and if necessary, only the peripheral part is relatively thin compared to other parts. It is processed and manufactured by subjecting the surface to a treatment such as plating as necessary.
[0005]
A conventional package 40 shown in FIG. 4 accommodates a circuit board 42 made of ceramic or the like in which a semiconductor element 43 is mounted on a metal package base 41, and the semiconductor element 43 and a transmission formed on the circuit board 42. The line 44 and a terminal electrode 45 that passes through the package base 41 and is connected to an external circuit (not shown) are connected by bonding wires 46, 47, 48, and 49, and a lid made of a thin metal plate. 30 is joined by a method such as seam welding shown in FIG. 5 and hermetically sealed.
[0006]
As shown in FIG. 5, the seam welding is performed by energizing welding while placing the lid 30 on the package base 41 placed on the base plate 51 and rotating and moving the lid body 52 as an electrode.
[0007]
Reference numeral 50 denotes an internal space in the package 40 formed by the package base 41 and the lid 30.
Here, in order to securely seal the lid 30 and the package base 41 by a method such as seam welding, it is necessary to reduce the warpage of the lid 30 as much as possible.
[0008]
However, since the thickness of the lid body 30 is as thin as about 0.1 mm to 0.3 mm, warping is likely to occur in various heat treatment processes in the manufacturing process or package assembly process. The gap between the body 30 and the package base 41 becomes large, and the roller 52 cannot be energized, so that the seam welding of the lid 30 cannot be performed when the package 40 is assembled, and the hermetic sealing failure occurs, thereby reducing the yield of the package 40 Problems occur.
[0009]
In particular, as shown in FIG. 3, the warping of the lid 30 has a shape like a lid 31 that is concave on the outside of the package 40 when assembled to the package 40 as shown in FIG. As described above, when pressing is performed by the roller portion 52 of the seam welding apparatus, the corner portion of the lid 30 is not in close contact with the package base 41 so that a gap is generated during seam welding, which tends to cause an airtight defect.
[0010]
For this reason, a process of measuring and selecting the warpage rate in the manufacturing process of the lid 30 is necessary, but the addition of the screening process has been a factor of an increase in cost and a decrease in yield.
[0011]
Further, even when the lid 30 is not warped at normal temperature, the warping may occur due to heating in a drying process or a welding process in the assembly process of the package 40.
[0012]
Even in this case, as shown in FIG. 3B, the warping of the lid 30 often causes a so-called twist in which the warping directions of the two opposite sides are different. In this case, as shown in FIG. In the process, when the lid 30 and the package base 41 are pressed by the roller portion 52 of the seam welding apparatus, the gap between the two becomes large, the current cannot be supplied, and seam welding is impossible or the airtightness is poor. And the yield of the package 40 was reduced.
[0013]
As means for solving such a problem, a method (Patent Document 1) for preventing warpage and deformation by providing a convex portion for reinforcement on a part of the lid 30 is disclosed.
[0014]
In addition, a method is disclosed in which a concave shape is provided on at least two opposite sides of the upper surface of the package base 41 to improve the close contact with the package base 41 at the four corners of the lid 30 and reduce airtight defects (Patent Document 2). Has been.
[0015]
On the other hand, since an approximately rectangular parallelepiped internal space 50 is formed inside these packages 40 after assembly, the package 40 has the same properties as a rectangular cavity resonator. Therefore, a cavity resonance occurs in a frequency band higher than the cutoff frequency determined by the dimensions of the internal space 50, and a phenomenon occurs in which the high frequency characteristics deteriorate. Therefore, when a high frequency circuit is formed by mounting semiconductor elements, optical elements or other circuit elements operating in the frequency band on the package 40, the cut-off frequency is reduced by designing the internal space 50 to be small. It must be sufficiently higher than the frequency band in which the circuit operates.
[0016]
However, as the operating frequency of the circuit built in the package 40 increases, it is necessary to manufacture the internal space 50 with a sufficiently small size so that the cutoff frequency of the package 40 becomes higher than the operating frequency. It becomes difficult. For this reason, cavity resonance occurs in the vicinity of the operating frequency of the circuit, resulting in a problem that high frequency characteristics as a device deteriorate.
[0017]
In particular, in recent years, demands for higher speeds of optical communication and wireless communication have increased, and the operating frequency of these circuits has been increased more and more, and such a problem is inevitable.
[0018]
Further, in the package 40 for a high frequency circuit, not only cavity resonance but also a self-feedback oscillation phenomenon of an amplifier mounted in the package 40 may be caused. That is, the electromagnetic wave radiated from the high-frequency transmission line formed in the package 40 and the semiconductor element 43 is reflected by the lid 30, so that an unnecessary signal is fed back between the amplifier input / output lines and unnecessary oscillation occurs.
[0019]
As a means for solving such a problem, a method of disposing a radio wave absorber on a part of the lid 30 so as to occupy at least one corner portion of the internal space 50 (Patent Document 3) is disclosed.
[0020]
Further, the electromagnetic wave absorber and the lid 30 are not fixed by a method such as adhesion, but are embedded in the package 40 by being sandwiched between the package base 41 or by providing a locking portion on the lid 30 (Patent Document 4). Is disclosed.
[0021]
[Patent Document 1]
JP-A-5-144959
[0022]
[Patent Document 2]
JP 2001-244355 A
[0023]
[Patent Document 3]
JP-A-6-236935
[0024]
[Patent Document 4]
JP-A-6-338696
[0025]
[Problems to be solved by the invention]
However, as disclosed in Patent Document 1, in order to provide the cover 30 with a reinforcing convex portion, a die for drawing is necessary in the process of manufacturing the cover 30, and the cover 30 It was a factor of cost increase. Providing the convex portion on the lid 30 is an obstacle when the internal space 50 of the package 40 is narrowed or the height of the package base 41 is increased to save the mounting surface and the device. It was.
[0026]
In addition, as disclosed in Patent Document 2, in order to perform concave processing on the upper surface of the package base 41, press processing with a large press machine or special grinding processing is necessary, so there is no mass productivity. There was a problem that the unit price of the package 40 was high.
[0027]
Furthermore, the method of forming the concave shape on the upper surface of the package base 41 by press working is not appropriate because it causes distortion in the entire package base 41 and leads to a decrease in mountability and a decrease in the positional accuracy of the optical element.
[0028]
Further, as disclosed in Patent Document 3, if the radio wave absorber is arranged in the lid body 30 so as to occupy at least one corner portion of the internal space 50, the lid body 30, the radio wave absorber, and the bonding agent wire Due to the difference in expansion coefficient, a partial stress is generated in the vicinity of the corner portion of the lid 30 to cause warpage.
[0029]
As described above, the warp near the corner of the lid 30 is particularly likely to cause a hermetic seal failure, which causes a reduction in the yield of the package 40.
[0030]
Further, as disclosed in Patent Document 4, in the method of fixing the radio wave absorber to the lid body 30 by pinching or locking, warping occurs due to the difference in linear expansion coefficient between the radio wave absorber, the lid body 30 and the bonding agent. Therefore, the warping of the lid 30 is reduced and the hermetic sealing failure can be reduced. On the other hand, special processing for providing a locking portion on the lid 30 or the package base 41 is necessary, which causes an increase in cost. It was.
[0031]
In addition, when vibration is applied from the outside after assembly, the radio wave absorber moves inside the package 40, and the peripheral portion of the radio wave absorber material is dropped to generate dust, which adheres to the circuit inside the package 40 and becomes a circuit. Have caused problems such as short-circuiting the film or adhering to the optical element to deteriorate the transmission characteristics.
[0032]
[Means for Solving the Problems]
Accordingly, the present invention provides a metal semiconductor element package lid for housing a semiconductor element in combination with a package base, wherein both the long side and the short side warpage of the semiconductor element package lid are semiconductor. It is characterized by having a convex relationship in the outer direction of the element package.
[0033]
And the curvature of the long side direction of the said package lid | cover for semiconductor elements is a magnitude | size of 0.1%-1.0% with respect to the length of the said long side, It is characterized by the above-mentioned.
[0034]
Further, the package lid for a semiconductor element has a configuration in which an additional member having a linear expansion coefficient different from that of the base material is attached to at least one main surface of a metal base material, and the additional member is formed from the base material. The linear expansion coefficient is large and the structure is attached to a surface corresponding to the inside of the semiconductor element package, or the additional member has a smaller linear expansion coefficient than the base material, and the semiconductor. A feature is that the structure is attached to a surface corresponding to the outside of the element package.
[0035]
Further, the additional member is an electromagnetic wave absorber having a linear expansion coefficient larger than that of the base material, and has a structure attached to a surface corresponding to the inner side of the semiconductor element package.
[0036]
In addition, the semiconductor element package lid is used for a semiconductor element package.
[0037]
[Action]
As in the present invention, the warp in the long side direction and the warp in the short side direction when both of the semiconductor element package lids are viewed in plan are convex in the same direction. Even under conditions where warpage is likely to occur, since the warp as described above is provided in advance in the semiconductor device package lid, the effects of expansion and contraction due to heating and the effects of residual stress are caused by the heat treatment step and the like. Since it is possible to prevent further warping from occurring and to prevent new warping in a different direction, it is easy to align the warping direction when combined with the package case. It can be convex in the direction, the adhesion of the lid corner in the assembling process becomes good, and airtight defects can be prevented more.
[0038]
Further, the warpage in the long side direction of the package lid for a semiconductor element is set to a size of 0.1% to 1.0% with respect to the length of the long side, thereby causing distortion generated by the heat treatment process. And the gap between the joints formed by the lid and the package case can be reduced.
[0039]
Further, the semiconductor device package lid can be easily aligned in the direction of warping by attaching an additional member having a different linear expansion coefficient to at least one of a metal base material and the main surface of the base material. In addition, by appropriately selecting additional members having different linear expansion coefficients, it is possible to change the magnitude of the warp, and to warp the long side and the short side in the same direction.
[0040]
Furthermore, since a radiated electromagnetic wave can be prevented by using a radio wave absorber having a linear expansion coefficient larger than that of the base material for the additional member, resonance of the semiconductor element package can be prevented.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0042]
(A) of FIG. 1 is a perspective view showing an example of the present invention, and (b) and (c) show other examples of the lid of the present invention, near the center of the short side in the long side direction of the lid. FIG. FIG. 2 is a cross-sectional view showing an example of a package using the lid of the present invention.
[0043]
The lid 10 in FIG. 1 (a) is made of a substantially rectangular base material 1 made of metal having surfaces 1a and 1b, and the base material 1 is formed so that the surface 1a side is convex, and the surface 1a, 1b constitutes the outer surface and the inner surface of the package, respectively.
[0044]
Moreover, when the dimension of the long side is L1, the amount of warpage of the long side of the metal base 1 is t1.
[0045]
Further, since the warp of the long side and the warp of the short side of the lid 10 are both convex in the same direction, an increase in the warp rate and a twist are not caused at the time of temperature rise in the heat treatment process of the package. The yield is improved without causing airtight defects in the assembly process.
[0046]
Furthermore, the yield in the package assembly process is further improved by setting t1 / L1 × 100 (%) to 0.1% to 1.0%.
[0047]
A package 20 shown in FIG. 2 accommodates a circuit board 22 made of ceramics or the like in which a semiconductor element 23 is mounted on a metal package base 21, and the semiconductor element 23 and a transmission formed on the circuit board 22. The line 24 and a terminal electrode 25 that passes through the package base 21 and is connected to an external circuit (not shown) are connected by bonding wires 26, 27, 28, and 29. Then, a lid 12 made of a thin metal plate joined to the surface 1b of the metal base 1 on the package base 21 side by using a radio wave absorber as the additional member 3 and solder as a bonding agent, and a method such as seam welding. Are joined and hermetically sealed.
[0048]
An internal space 15 in the package 20 formed by the package base 21 and the lid 12 is used.
[0049]
That is, the present inventors pay attention to the cause of the airtight failure in the package 20 due to the warp of the lid body 30, and the warp is convex in the same direction on the long side and the short side, and the outside of the package case It has been found that the airtight defect can be prevented by projecting in the direction.
[0050]
The lid is preferably flat in nature. However, if the lid is flat, the lid is deformed and warped by heat treatment in an assembly process for joining to the package base 21. However, if it remains as it is, there is a risk of warping of so-called distortions that warp in different directions, and if this is to be seam welded as it is, the roller part 51 as shown in FIG. Even if the lid 30 is damaged or, for example, joined without breakage, it is not preferable because the four sides of the lid 30 are not easily brought into close contact with the package base 41 and airtight defects are likely to occur.
[0051]
That is, as in the present invention, the warpage of the lid 10 (12) is convex in the same direction on the long side and the short side, and is convex in the outer direction of the package case 21, thereby Since the four sides of the lid body 10 (12) can be brought into close contact with each other when pressed by the roller portion 51, poor airtightness can be prevented.
[0052]
However, the warp is not limited to an infinitely large amount, and it is important that the bonding agent is set within a range in which the gap generated by the warp between the lid 10 (12) and the package base 21 can be sufficiently filled. From that point of view, the warp rate t1 / L1 × 100 (%) is preferably 0.1% to 1.0%, and more preferably in the range of 0.1% to 0.5%. .
[0053]
When the warp rate is less than 0.1%, the uneven distortion warp is likely to occur, and the effect of the present invention is reduced. When the warp rate exceeds 1.0%, the lid 10 (12) and the package base are reduced. This is because the gap with 21 is increased, and airtightness is likely to occur.
[0054]
Here, in order to make both the warp in the long side direction and the warp in the short side direction of the lid body 10 convex in the same direction, the metal base material 1 is punched from the base material using a die with a press. The upper and lower punch portions of the mold may be provided with a curved surface so that a desired shape can be obtained, or the upper and lower punch portions are once punched or etched into the predetermined shape from the base material only at the outer edge. What is necessary is just to press-work with the metal mold | die provided with the curved surface which can obtain a desired shape.
[0055]
More preferably, as shown in FIGS. 1B and 1C, the additional member 2 or 3 is provided on the base material 1, and a bonding agent is provided on one of the surfaces 1a and 1b of the base material 1. The lids 11 and 12 may be configured so as to obtain a desired warpage by adjusting the linear expansion coefficient of the additional member 2 or 3 and the curing temperature of the bonding agent.
[0056]
That is, if the additional member 2 or 3 having a linear expansion coefficient different from the linear expansion coefficient of the base material 1 is joined, the base material 1 is always convex to either side, and the lid body 11 or the lid body 12 is attached. You will get.
[0057]
In addition, when attaching the additional member 3 to the 1b surface side of the base material 1, by making the linear expansion coefficient of the additional member 3 larger than that of the base material 1, both due to a solder melting point at the time of solder joining and a temperature difference between normal temperatures. Due to the shrinkage difference, convex warpage can be generated on both the long side and the short side.
[0058]
On the contrary, when the additional member 2 is attached to the 1a surface side of the base material 1, the linear expansion coefficient of the additional member 2 is made smaller than that of the base material 1. Due to the shrinkage difference, convex warpage can be generated on both the long side and the short side.
[0059]
As a result, compared to the case where warpage is added to the lid using a mold, there is less variation in the warpage rate, a stable shape can be warped, and the yield of the lid can be improved. It becomes possible.
[0060]
Furthermore, a radio wave absorber in which the linear expansion coefficient of the additional member 3 is set to be larger than that of the base material 1 may be used. At the same time, defects can be reduced, and radiated electromagnetic waves generated from the semiconductor element 23, the transmission line 24, the bonding wire 25, and the connection portions thereof are absorbed and attenuated by the radio wave absorber constituting the additional member 3. As a result of the suppression of the internal reflection of the radiated electromagnetic wave by the material 1, the cavity resonance and the oscillation phenomenon are suppressed, and it becomes possible to have excellent frequency characteristics at a high frequency.
[0061]
In addition, as the metal substrate 1, for example, a thin plate such as an Fe—Ni—Co alloy is processed into a predetermined shape by a method such as press punching or etching, and Ni plating is performed for the purpose of surface protection, oxidation prevention, and the like. After the application, the substrate 1 shown in FIGS. 1A to 1C can be obtained by further Au plating.
[0062]
Further, the base material 1 is not limited to Fe—Ni—Co alloy, but may be selected from Fe, Fe—Ni, Cu, Cu—W, Al, other metals or metal alloys. In order to improve cycle performance, it is appropriate to use a material having a linear expansion coefficient close to that of the package base.
[0063]
The difference in coefficient of linear expansion between the additional member and the lid is 0.5X10 so that extreme stress is generated and peeling does not occur.^―6/ ° C to 5X10^―6/ ° C is preferred.
[0064]
Since the additional member has a uniform warp as much as possible to the area of the lid, it preferably has an area of 90% or more of the lid.
[0065]
In addition, when the additional members 2 and 3 are Fe-Ni-Co alloy, Fe, Fe-Ni alloy, Cu, Cu-W alloy, Al, other metal or metal alloy, the type of metal or the type of alloy and It can adjust so that a desired linear expansion coefficient may be obtained by adjusting a mixture ratio.
[0066]
Furthermore, when using a radio wave absorber as the additional members 2 and 3, adjusting the type and blending ratio of the base resin, ceramics, and magnetic material so that a desired linear expansion coefficient can be obtained. Can do.
[0067]
Examples of ferrite wave absorbers include Mn—Zn ferrite, Ni—Zn ferrite, Cu—Zn ferrite, Cu—Zn—Mg ferrite, Mn—Mg—Al ferrite, Y-type hexagonal ferrite, Z It may be selected from type hexagonal ferrite, M type hexagonal ferrite, and the like.
[0068]
In addition, when using a radio wave absorber composed of a composite material of resin and magnetic material, for example, epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, polyimide resin, etc. can be used as the resin. The magnetic material may be selected from amorphous magnetic metal alloys, Ni-Fe alloys, carbonyl iron, other soft magnetic metal materials, or the ferrite wave absorber.
[0069]
【Example】
First, a thin plate made of an Fe—Ni—Co alloy is processed into a predetermined outer side shape by etching to obtain the base material 1, and then a long side and a short side are formed with a mold having a curved shape on the punch surface. Pressing was performed so that both sides were convex in the same direction, Ni plating was applied to the surface by electrolytic plating, and Au plating was further applied by electrolytic plating to produce lid 10. At that time, a sample shown in Table 1 was manufactured in which the curvature of the punch surface of the mold was changed and the warpage ratio of the long side was changed from 0% to 2%.
[0070]
In addition, as shown in FIG. 2, after processing a thin plate made of Fe—Ni—Co alloy into a predetermined outer shape by etching, the same metal alloy is formed after applying Ni and Au plating to form a base material 1. However, the additional member 2 or 3 in which the linear expansion coefficient is changed by adjusting the respective components and ratios is manufactured by the same method as that for the base material 1, and is bonded to the base material 1 using solder, The bodies 11 and 12 were produced. At that time, a sample was prepared by adjusting the linear expansion coefficient of the additional member 2 or 3 and the melting point of the solder, and changing the warpage rate of the long side from 0% to 2%.
[0071]
Next, the additional member 3 of the lid 12 is changed to a radio wave absorber, and is attached to the 1b surface side of the base material 1 using solder. The long side and the short side are convex and the warping rate is 0.8% and 1%. 0.0% of the lid body 12 was produced.
[0072]
In addition, although the ferrite type ceramic material was used for the radio wave absorber, the radio wave made of a composite material of a resin and a magnetic material in consideration of the operating frequency of the package 20, the required absorption characteristics, heat resistance, reliability, and the like. An absorber may be used. Further, in order to impart solder wettability to the surface of the radio wave absorber, a metal film of Ni and Au was applied to the bonding surface of the radio wave absorber with the substrate 1 by a vacuum deposition method.
[0073]
In addition, the dimensions of the additional members 2 and 3 are set to be smaller than the dimensions of the base material 11 so that the additional members 2 and 3 and solder and the like do not overlap the peripheral portion for seam welding in combination with the package base 21. .
[0074]
Next, the produced lids 11 and 12 are subjected to a drying process for 24 hours in an oven at 200 ° C., which is a drying condition in the assembly process of the package 20, and then the warp rate and the change in the warp direction are returned to room temperature. Was measured.
[0075]
Then, as shown in FIG. 2, each lid 10 was hermetically sealed to the package base 21 on which the circuit board 22 was mounted by seam welding, and 100 packages 20 were produced. Here, the terminal electrode 25 of the package 20 and the transmission line 24 formed on the circuit board 22 are connected by bonding wires 28 and 29.
In this embodiment, in order to observe the cavity resonance phenomenon of the package 20 in more detail, the semiconductor element 23 is not actually mounted, but only the transmission lines 22 and 24 are used instead.
[0076]
Next, the hermetic failure rate of the package 20 produced by the above method was examined by a pressurized helium leak test. As a criterion for determining a hermetic seal failure, a helium leak rate of 1.0 × 10^-6atm · cm³The rate of failure was calculated assuming that a product having a value larger than that was regarded as defective.
[0077]
Further, probes for measuring high frequency characteristics are connected to the terminal electrodes on the high frequency input side and output side, respectively, and the probes are connected to port 1 (202) and port 2 (203) of the network analyzer 201 to transmit the package 20 respectively. Characteristics were evaluated. The transmission characteristics are obtained when the conventional lid 30 made of only metal (samples 1 and 2 as a comparative example) and when the lids 10, 11 and 12 of the present invention are used (samples 28 and 29 as examples). ) Minimum power transmission coefficient (S₂₁ ^min) Was measured from 100 MHz to 40.1 GHz using the network analyzer 201, and the presence or absence of the resonance suppression effect was confirmed.
[0078]
[Table 1]

[0079]
As a result of the experiment, as shown in Table 1, Samples 3, 5, 7, 9, 11, 13-15, and 17-25, which are examples of the present invention, were dried at 200 ° C. for 24 hours in the package assembly process. Even after the treatment, the direction of warping and the change in the warpage rate were small, and the leak failure rate was very small in the He leak test after assembly, while the samples 1, 2, 4, 6, 8, 10, and 13 have a warpage rate increased by a heat treatment for drying at 200 ° C. for 24 hours, and warping of distortion in which the direction of warping of the long side and the short side is different. At the corners, the adhesion with the package base was poor, and the leak rate was high in the He leak test after assembly.
[0080]
In addition, in the sample 17 in which the warp of the long side and the short side of the lid are both convex toward the inside of the package, which is an example of the present invention, the close contact with the package base at the corner of the lid is also deteriorated. In the He leak test after assembly, the leak defect rate was high.
[0081]
Samples 5, 7, 9, 14, 15, 17, 20, 22, 24, and 25 having warpage rates of 0.1 to 1.0%, which are examples of the present invention, are comparative examples. Compared with Samples 3, 13, 18, 19, and 23 where the warpage rate is less than 0.1 and the warpage rate exceeds 1.0%, the yield in the He leak test after package assembly is better. It was confirmed.
[0082]
Further, in the samples 24 and 25 using the radio wave absorber as the additional member, the generation of distortion and the increase in the warp rate are not observed even after the drying process at 200 ° C. for 24 hours in the package assembling process, and the leak defect rate is high. At the same time as 0%, the effect of suppressing cavity resonance in the range up to 40 GHz was confirmed.
[0083]
According to the above series of experimental results, the use of the lid 1 for semiconductor packages according to the claims of the present invention produces a package 20 having excellent airtightness, high reliability, and excellent transmission characteristics at high frequencies. It was confirmed that it would be possible.
[0084]
【The invention's effect】
As described above in detail, according to the present invention, in a package lid for a semiconductor element that houses a semiconductor element in combination with a package base, the warp of the long side and the short side when the lid is viewed in plan is in the same direction. It is possible to obtain a highly reliable package for a semiconductor element having excellent hermetic sealing properties by setting the warpage rate of the long side to 0.1 to 1.0%.
[0085]
Then, the semiconductor element package lid can be easily aligned in the direction of warping by attaching an additional member having a different linear expansion coefficient to at least one of the metal base and the main surface of the base. By appropriately selecting additional members having different linear expansion coefficients, it becomes possible to change the warpage, and the warpage of the long side and the short side can be made convex in the same direction. You can adjust the rate.
[0086]
Furthermore, when the radio wave absorber is attached to the inner surface side of the lid, it is possible to obtain a semiconductor package that is excellent in hermetic sealing properties and also excellent in high-frequency transmission characteristics.
[Brief description of the drawings]
1A is a perspective view of a package lid for a semiconductor element of the present invention, and FIG. 1B is a cross-sectional view showing another example of the package lid for a semiconductor element of the present invention. .
FIG. 2 is a cross-sectional view of a semiconductor device package according to the present invention and a schematic diagram showing a method for measuring transmission characteristics.
3A and 3B are perspective views of a conventional package lid for a semiconductor element.
FIG. 4 is a cross-sectional view of a conventional semiconductor device package.
FIG. 5 is a schematic view showing an assembling process of a conventional semiconductor device package.
[Explanation of symbols]
1, 31, 32... Base material
1a, 1b ... surface
2,3 ... Additional members
10, 30... Semiconductor device package lid
20, 40 ... Semiconductor device package
21,41 ... Package base
22, 42 ... Circuit board
23, 43 ... Semiconductor element
24, 44 ... Transmission line
25, 45 ... Terminal electrodes
26, 27, 28, 29 ... bonding wires
15, 50 ... Internal space
46, 47, 48, 49 ... bonding wires
51 ... Base plate
52 ... Roller part
200 ... Transmission characteristic measuring device
201: Network analyzer
202 ... port 1
203 ... Port 2

Claims (5)

In a metal semiconductor package lid for housing a semiconductor element in combination with a package base, the semiconductor element package lid protrudes outward in the semiconductor element package in both the long side direction and the short side direction. A package lid for a semiconductor element, characterized by having a warp that results in 2. The semiconductor according to claim 1, wherein a warp in a long side direction of the package lid for the semiconductor element is 0.1% to 1.0% with respect to a length of the long side. Device package lid. The package lid for a semiconductor element has a configuration in which an additional member having a linear expansion coefficient different from that of the base material is attached to at least one main surface of a metal base material, and the additional member is configured as described above. A structure having a larger linear expansion coefficient than that of the material and attached to a surface corresponding to the inside of the semiconductor element package, or the additional member has a smaller linear expansion coefficient than that of the base material, and is disposed outside the semiconductor element package. 3. The package lid for a semiconductor device according to claim 1, wherein the lid is a structure attached to a corresponding surface. 4. The additional member is an electromagnetic wave absorber having a linear expansion coefficient larger than that of the base material, and has a structure attached to a surface corresponding to the inner side of the semiconductor element package. A package lid for a semiconductor device according to any one of the above. A semiconductor element package using the semiconductor element package lid according to claim 1.

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