WO2019082602A1

WO2019082602A1 - Bonding structure, semiconductor package and semiconductor device

Info

Publication number: WO2019082602A1
Application number: PCT/JP2018/036560
Authority: WO
Inventors: 森　隆二; 谷口　雅彦
Original assignee: 京セラ株式会社
Priority date: 2017-10-26
Filing date: 2018-09-28
Publication date: 2019-05-02
Also published as: CN111316425B; CN111316425A; JP6978509B2; CN117936483A; JPWO2019082602A1

Abstract

The present invention relates to a bonding structure and the like that facilitate characteristic impedance matching between a metal terminal and a line conductor. According to the present invention, a bonding structure C includes: a metal terminal 1 having an end surface 1a; a line conductor 2 having a side surface 2a which a portion of the end face 1a of the metal terminal 1 faces; and a metal particle. The bonding structure is located so as to cover an area from a first end portion 1b including the end face 1a of the metal terminal 1 to a second end portion 2b including the side surface 2a of the line conductor 2, and is provided with a bonding material 3 bonded to the metal terminal 1 and the line conductor 2.

Description

Junction structure, semiconductor package and semiconductor device

The present invention relates to a junction structure in which a metal terminal and a line conductor are joined, a semiconductor package, and a semiconductor device.

As a semiconductor package on which a semiconductor element such as an optical semiconductor element is mounted, one including a substrate on which the semiconductor element is mounted and a lead terminal (metal terminal) fixed to the substrate is known. The mounting of the semiconductor element and the fixing of the lead terminals to the substrate are performed, for example, through an insulating member such as a dielectric substrate.

In this case, in the semiconductor package, the signal terminal is bonded and fixed to the dielectric substrate via a brazing material such as gold-tin or tin-silver. The signal terminals are metal lead terminals or the like. A metal layer is previously provided on a portion of the surface of the dielectric substrate to which the brazing material is to be joined. The end of the lead terminal is joined to be opposed to the metal layer along the longitudinal direction of the lead terminal (see, for example, Patent Document 1).

International Publication No. 2017/033860

2. Description of the Related Art In recent years, the frequency of a signal transmitted through a transmission path formed of a signal terminal and a metal layer is increasing. Therefore, it has been required to match the characteristic impedance in the transmission line with higher accuracy. There is also a need for a junction structure that facilitates such a semiconductor package configuration.

A junction structure according to one aspect of the present invention includes a metal terminal having an end surface, a line conductor having a side surface on which a part of the end surface of the metal terminal faces, metal particles, and the metal A bonding material is disposed so as to cover from the end face of the terminal to a part of the line conductor, and is joined to the metal terminal and the line conductor.

A semiconductor package according to one aspect of the present invention includes a substrate having a first surface and a second surface opposite to the first surface, a line conductor positioned on the first surface side of the substrate, and the substrate of the substrate A metal terminal penetrating from the second surface to the first surface and having an end on the first surface side, and including metal particles, and between the end of the metal terminal and the line conductor And a joining material interposed between the end of the metal terminal and the line conductor.

A semiconductor device according to one aspect of the present invention includes the semiconductor package having the above configuration, and a semiconductor element located on the first surface side and electrically connected to the line conductor.

The objects, features and advantages of the present invention will become more apparent from the following detailed description and the drawings.
It is sectional drawing which shows the bonded structure of embodiment of this invention. FIG. 1 is a perspective view of a semiconductor package according to an embodiment of the present invention. It is the perspective view seen from the other side of FIG. 2A. It is a top view of the semiconductor package of the embodiment of the present invention. FIG. 3B is a cross-sectional view taken along line XX of FIG. 3A. It is sectional drawing which shows the bonded structure of other embodiment of this invention. It is sectional drawing which shows the bonded structure of other embodiment of this invention. It is sectional drawing which shows the bonded structure of other embodiment of this invention. It is sectional drawing which shows the bonded structure of other embodiment of this invention. It is sectional drawing which shows the bonded structure of other embodiment of this invention. FIG. 1 is a perspective view of a semiconductor device according to an embodiment of the present invention. It is a figure showing a simulation model. It is a figure showing a simulation model. It is a figure which shows a simulation result. It is a figure which shows a simulation result.

The junction structure and the semiconductor package according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a bonded structure according to an embodiment of the present invention. FIG. 2A is a perspective view of a semiconductor package according to an embodiment of the present invention, and FIG. 2B is a perspective view seen from the opposite side of FIG. 2A. FIG. 3A is a plan view of the semiconductor package according to the embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along line XX in FIG. 3A.

The junction structure C according to the embodiment of the present invention includes a metal terminal 1 having an end face 1 a, a line conductor 2 having a side face 2 a facing the end face 1 a, and metal particles. And a bonding material 3 which is positioned to cover from the end face 1a to a part of the line conductor 2 (for example, the second end 2b including the side surface 2a) and is joined to the metal terminal 1 and the line conductor 2 There is. The junction structure C includes, for example, a metal terminal 1 for external connection, a line conductor 2 electrically connected to a semiconductor element, and a substrate 4 on which the metal terminal 1 and the line conductor 2 are arranged in a predetermined positional relationship. It is used for joining via the joining material 3 of the metal terminal 1 and the line conductor 2 in the semiconductor package containing. In the semiconductor package 10 according to the embodiment of the present invention, the metal terminal 1, the line conductor 2, the bonding material 3 interposed between the metal terminal 1 and the line conductor 2, the metal terminal 1 and the line conductor 2 are arranged. And the junction structure C of the above embodiment between the metal terminal 1 and the line conductor 2.

Further, in the example shown in FIGS. 2A, 2B, 3A and 3B, the semiconductor package 10 further includes the insulating plate 5 on which the line conductor 2 is actually disposed and fixed to the substrate 4, and the insulating plate 5. And a submount 6 joined. The substrate 4 has a first surface 4a and a second surface 4b opposite to the first surface 4a, and a through hole penetrating the substrate 4 in the thickness direction between the first surface 4a and the second surface 4b. It has 4c. The metal terminal 1 penetrates the substrate 4 from the second surface 4 b to the first surface 4 a through the through hole 4 c. The end face 1 a of the metal terminal 1 and the first end 1 b including the end face are located on the first face 4 a side. The insulating plate 5 is positioned on the side of the first surface 4 a of the substrate 4, whereby the line conductor 2 is disposed on the side of the first surface 4 a of the substrate 4. On the side of the first surface 4 a of the substrate 4, the metal terminal 1 and the line conductor 2 are bonded to each other via the bonding structure C of the above-described configuration. That is, a part of the end face 1 a of the metal terminal 1 is opposed to the side face 2 a of the line conductor 2. A bonding material 3 including metal particles is positioned so as to cover from a first end 1 b including the end face 1 a of the metal terminal 1 to a second end 2 b including the side 2 a of the line conductor 2. The bonding material 3 is bonded to the metal terminal 1 and the line conductor 2, and the metal terminal 1 and the line conductor 2 are bonded to each other by the bonding material 3.

The semiconductor package 10 hermetically seals a semiconductor element (not shown) such as an optical semiconductor element, for example. The semiconductor element is mounted on the insulating plate 5 and electrically connected to the line conductor 2. When the first surface 4a side of the substrate 4 on which the semiconductor element is mounted is sealed with a metal case (CAN) (not shown), a so-called TO (Transistor Outline) -CAN type semiconductor package is formed. When the semiconductor device is an optical semiconductor device, a metal case having an opening for input and output of an optical signal is used.

In the bonded structure C of the embodiment, the metal terminal 1 has a function as a conductive path for external connection in the semiconductor package 10 as described above, for example. In this case, the metal terminal 1 is a strip-like or rod-like lead (pin) terminal. The metal terminal 1 is made of, for example, a metal material such as an iron-nickel-cobalt alloy, an iron-nickel alloy, or an alloy material containing copper. If the metal terminal 1 is made of, for example, an iron-nickel-cobalt alloy, apply a metal processing appropriately selected from rolling, punching, cutting, etching, etc. to an ingot (lump) of iron-nickel-cobalt alloy Can be produced by

The metal terminals 1 may be fixed to the substrate 4 such that the plurality of metal terminals 1 are arranged side by side as in the examples shown in FIGS. 2A, 2B, 3A and 3B, for example. In the example shown in FIGS. 2A, 2B, 3A and 3B, a pair of metal terminals 1 for signal transmission is disposed through the substrate 4. Each metal terminal 1 has a first end 1 b including an end face 1 a located on the first surface 4 a side of the substrate 4 and an end face 1 a. It is also possible to regard the portion of the metal terminal 1 located on the side of the first surface 4 a of the substrate 4 (the portion to be hermetically sealed) as the first end portion 1 b.

In the example shown in FIG. 2A, FIG. 2B, FIG. 3A and FIG. 3B, the ground terminal 7 is disposed side by side with the pair of metal terminals 1. The ground terminal 7 can be manufactured by the same method using the same metal material as the metal terminal 1. Details of the configuration and function of the metal terminal 1 in the semiconductor package 10 will be described later.

The metal terminal 1 is, for example, a linear shape having a length of 1.5 to 22 mm and a diameter of 0.1 to 1 mm. In the case of signal transmission, in consideration of mechanical strength of the pair of metal terminals 1, matching of characteristic impedance (hereinafter simply referred to as impedance) and miniaturization of the semiconductor package 10, the diameter of each metal terminal 1 is 0.15. It shall be ~ 0.25 mm. If the diameter of the metal terminal 1 is 0.15 mm or more, for example, it is easy to suppress bending or the like of the metal terminal 1 when the semiconductor package 10 is handled, which is advantageous in improving the workability and the like. Further, if the diameter of the metal terminal 1 is 0.25 mm or less, the diameter of the through hole 4c through which the metal terminal 1 penetrates can be kept small, so that the substrate 4 can be miniaturized, that is, the semiconductor package 10 can be miniaturized. Is effective.

The line conductor 2 has, for example, a function as a conductor for connecting semiconductor elements in the semiconductor package 10. Electrical connection between the semiconductor element and the line conductor 2 is made via a low melting point brazing material such as a bonding wire or a solder. In the case of a bonding wire, a bonding wire such as a gold wire or an aluminum wire is sequentially bonded to the semiconductor element (electrode) and the line conductor 2 by a bonding method such as a ball bonding method. Thereby, the semiconductor element can be electrically connected to the line conductor 2. The line conductor 2 and the metal terminal 1 are bonded to each other through the bonding material 3 to form a conductive path for electrically connecting the semiconductor element and the external electric circuit.

As described above, the line conductor 2 is formed, for example, on the surface of the insulating plate 5. The insulating plate 5 is fixed to the side of the first surface 4 a of the substrate 4, and the line conductor 2 is positioned on the side of the first surface 4 a of the substrate 4. The line conductor 2 has a side surface 2a on the first surface 4a side, and has a second end 2b including the side surface 2a. Further, on the first surface 4 a side, the end surface 1 a of the metal terminal 1 is positioned to face the side surface 2 a of the line conductor 2. Only a part of the end face 1 a of the metal terminal 1 may be opposed to the side face 2 a of the line conductor 2. The first end 1 b of the metal terminal 1 and the second end 2 b of the line conductor 2 are bonded to each other via a bonding material 3 described later. The bonding material 3 is also bonded to the end surface 1a and the side surface 2a.

The line conductor 2 is, for example, a metal material appropriately selected from metal materials such as tungsten, molybdenum, manganese, copper, silver, gold, palladium, platinum, rhodium, nickel and cobalt, or a metal material of an alloy containing these metal materials. It is formed by The line conductor 2 can be formed in the form of a metallized layer, a plating layer, a thin film layer or the like. The line conductor 2 is formed on the insulating plate 5 as described above, and when it contains a thin film layer of gold, copper, nickel, silver or the like, titanium, chromium, tantalum, niobium, nickel-chromium alloy, nitrided It may further include an adhesion metal layer such as tantalum. The adhesion metal layer is located between the insulating plate 5 and the thin film layer, and has a function of improving the adhesion of the line conductor 2 to the insulating plate 5.

The thickness of the line conductor 2 is set to about 0.1 to 5 μm in consideration of, for example, reduction of electric resistance, suppression of internal stress, and the like. The thickness of the adhesion metal layer is set to about 0.01 to 0.2 μm in consideration of the improvement of the adhesion to the insulating plate 5 and the suppression of the internal stress. The line conductor 2 may further include a diffusion suppression layer that suppresses mutual diffusion between the adhesion metal layer and the thin film layer. The diffusion suppression layer can be formed of, for example, a metal material such as platinum, palladium, rhodium, nickel, or a titanium-tungsten alloy. The thickness of the diffusion suppression layer is set to about 0.05 to 1 μm in consideration of, for example, the above-described suppression of mutual diffusion and suppression of the electrical resistance in the line conductor 2.

In addition, when the line conductor 2 is disposed on the surface of the insulating plate 5 by a metallizing method, it is appropriately selected from metal materials such as tungsten, molybdenum, manganese, copper, silver, gold, platinum and palladium, for example. Metal materials may be included. In this case, for example, the line conductor 2 can be formed by sintering a metal paste prepared by kneading tungsten powder with an organic solvent, a binder, and the like with the insulating plate 5.

The insulating plate 5 is formed of, for example, a ceramic insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a silicon nitride sintered body, or a glass ceramic sintered body. If the insulating plate 5 is made of, for example, an aluminum oxide sintered body, it can be manufactured as follows. First, a slurry is prepared by adding and mixing an appropriate organic solvent and solvent to raw material powders such as aluminum oxide, silicon oxide, calcium oxide and magnesium oxide. Next, the slurry is formed into a sheet by a doctor blade method, a calender roll method or the like to obtain a ceramic green sheet (hereinafter also referred to as a green sheet). Thereafter, the green sheet is punched into a predetermined shape, laminated as necessary, and sintered at a predetermined temperature of about 1300 to 1600 ° C. The insulating plate 5 can be manufactured by the above steps.

When the line conductor 2 is formed of a metallized layer such as tungsten, a manufacturing method is used in which a metal paste for the metallized layer (line conductor 2) is printed on a surface of a green sheet to be the insulating plate 5 and fired simultaneously. May be In this case, the insulating plate 5 and the line conductor 2 can be integrally manufactured. Therefore, it is effective to improve the strength, productivity and the like of the connection between the line conductor 2 and the insulating plate 5.

The bonding material 3 is positioned so as to cover from the first end 1 b including the end face 1 a of the metal terminal 1 to the second end 2 b including the side 2 a of the line conductor 2. The bonding material 3 bonded to the first end 1b of the metal terminal 1 and the second end 2b of the line conductor 2 includes, for example, a metal material such as silver, copper, gold and palladium or a metal material of these metals. It contains metal particles made of a metal material such as an alloy. The metal particles are bonded to each other by metal bonding, and form a combined shape as the bonding material 3. Further, the metal particles are combined with the metal components contained in the metal terminal 1 and the line conductor 2 respectively. Thus, bonding is performed via the bonding material 3 between the metal terminal 1 and the line conductor 2.

The end face 1 a of the metal terminal 1 is perpendicular to the surface 2 bb of the line conductor 2 in the cross-sectional view (vertical cross-sectional view) in the vertical direction as shown in FIG. 1, for example. The direction perpendicular to the surface 2 bb of the line conductor 2 opposite to the insulating plate 5 is referred to as the upward direction, and the opposite direction is the downward direction. Furthermore, when the first surface 4 a is viewed from the side of the first surface 4 a of the substrate 4, the left and right direction with respect to the vertical direction is also defined. The surface 2 bb of the line conductor 2 is hereinafter referred to as the upper surface 2 bb. The upper surface 2 bb of the line conductor 2 constitutes a part of the second end 2 b of the line conductor 2. Further, the side surface 2 a of the line conductor 2 is substantially parallel to the end surface 1 a of the metal terminal 1. Therefore, the end face of the metal terminal 1 and the side face of the line conductor 2 can be disposed to face each other.

The junction structure C via the joining member 3 between the metal terminal 1 and the line conductor 2 is connected between the metal terminal 1 and the line conductor 2, that is, the external electrical circuit to which the metal terminal 1 is connected, and the line conductor 2 The transmission path of the signal between the semiconductor elements to be At this time, it is necessary to match the impedance between the metal terminal 1 and the line conductor 2 so as to cope with the high frequency (for example, 40 GHz or more) of the signal transmitted through the transmission path. On the other hand, in the junction structure C of the embodiment, such accuracy improvement in impedance matching is easy. The details of the accuracy improvement of the impedance matching are as follows.

That is, according to the bonding structure C of the embodiment, bonding is performed by the bonding material 3 in a state in which the end surface 1 a of the metal terminal 1 and the side surface 2 a of the line conductor 2 face each other. That is, in the present invention, the term "opposite" means that the metal terminal 1 and the line conductor 2 do not overlap in the longitudinal direction of the metal terminal 1 which is the direction in which the signal is transmitted. In other words, it means that the metal terminal 1 and the line conductor 2 do not overlap in a plan view when viewed in a direction perpendicular to the top surface 2 bb of the line conductor 2. Therefore, the change of the resistance in the transmission line due to the overlapping of the metal terminal 1 and the line conductor 2 is suppressed. Thereby, it is possible to reduce the change of the characteristic impedance due to the change of the resistance in the length direction of the transmission path. Therefore, it is possible to provide the junction structure C effective for improving the accuracy of the characteristic impedance matching in the transmission line of the high frequency signal constituted by the metal terminal 1 and the line conductor 2. In the present embodiment, the end face 1a of the metal terminal 1 and the side face 2a of the line conductor 2 face each other, and the end face 1a and the side face 2a are in direct contact with each other. Further, in a cross-sectional view in the vertical direction including the end face 1 a of the metal terminal 1, the lower surface of the line conductor 2 is located below the metal terminal 1.

Bonding between the metal terminal 1 and the line conductor 2 via the bonding material 3 is performed, for example, as follows. First, particles of the above-mentioned metal material such as silver (in fact, an aggregate of many particles) are kneaded with an organic solvent and a binder to prepare a paste. Next, the end face 1a of the metal terminal 1 is made to face the side face 2a of the line conductor 2 and aligned, the above-mentioned paste is placed on the aligned part, and these are temporarily fixed by a jig or the like. Then, these are heated with an electric furnace etc., and the metal particles in a paste are couple | bonded. At this time, polymerization or the like between binder components may occur. That is, in addition to the metal bond between metal particles, the bonding material 3 may include the action of bonding by the polymer of the organic component. The temperature of bonding by the paste containing the binder component is set to, for example, about 200 to 300.degree.

From such behavior of metal particles and the like at the time of bonding, the paste wets and spreads over the upper surface 2 bb located at the second end 2 b of the line conductor 2 and the metal terminal 1. Thereby, for example, a bonded structure C as shown in FIG. 1 can be produced.

At this time, if the paste contains an organic component that polymerizes with each other, the paste is hardened at a relatively low temperature by the polymer of the organic component, so the shape maintenance of the paste to be the bonding material 3 is easy . Therefore, bonding via the bonding material 3 between the first end 1 b of the metal terminal 1 and the second end 2 b of the line conductor 2 can be easily performed. Further, since bonding can be performed at a relatively low temperature, the workability of bonding via the bonding material 3 between the metal terminal 1 and the line conductor 2 and the improvement of productivity as the bonding structure C and the semiconductor package 10 are also effective. is there.

In addition, the metal particles in the bonding material 3 are fine particles (so-called submicron particles, subnanoparticles, etc.) having a particle size of about 1 μm or less in consideration of ease of bonding between metal particles, strength of bonding, and the like. It may be nanoparticles) or a mixture of microparticles and metal particles of micron size. The paste used as the bonding material 3 may contain an organic resin component that polymerizes with each other when such fine particles are used as metal particles. As such an organic resin component, a polymerizable carboxylic acid derivative etc. can be mentioned, for example.

FIG. 4 is an enlarged cross-sectional view of the main part of a bonded structure C according to another embodiment of the present invention. Parts in FIG. 4 similar to those in FIGS. 1 to 3B are assigned the same reference numerals. In the example shown in FIG. 4, the end surface 1 a of the metal terminal 1 and the side surface 2 a of the line conductor 2 face each other and are separated from each other. There is a gap 8 between the end surface 1 a and the side surface 2 a, and the bonding material 3 is located in the gap 8. That is, the end surface 1a of the metal terminal 1 which is not in direct contact with each other and the side surface 2a of the line conductor 2 are connected by the bonding material 3 and electrically connected to each other. The junction structure C and the semiconductor package 10 of the other embodiment are the same as the junction structure C and the semiconductor package 10 of the above embodiment in the other points. The description of these same points will be omitted.

In such a case, it is advantageous for effective relaxation of the thermal stress generated between the metal terminal 1 and the line conductor 2. That is, thermal stress caused by the difference in coefficient of thermal expansion between the metal terminal 1 and the insulating plate 5 between the metal terminal 1 made of a metal material as described above and the line conductor 2 fixed to the insulating plate 5 Can occur. At this time, the bonding material 3 containing a metal material such as silver, which is relatively easy to deform, is interposed between the two in such an amount (volume) that the gap 8 is filled, that is, an amount that allows easy deformation. Therefore, thermal stress generated between the metal terminal 1 and the line conductor 2 (insulation plate 5) due to the deformation of the bonding material 3 can be effectively alleviated.

In the case of this example, since it is advantageous for the relaxation of the thermal stress as described above, the mechanical fracture of the bonded structure C due to the thermal stress can be effectively suppressed. Therefore, in this case, the joint structure C is effective not only for improving the accuracy of impedance matching but also for improving the long-term reliability of the junction between the metal terminal 1 and the line conductor 2. In order to obtain such an effect of improving the reliability, the bonding material 3 preferably contains a metal material such as silver or copper having a relatively small elastic modulus (for example, Young's modulus). In the case where the bonding material 3 contains silver or copper, it is also advantageous to reduce the conduction resistance in the bonding material 3.

Moreover, if the bonding material 3 contains fine particles such as silver as described above, (macroscopically) deformation as the bonding material 3 due to displacement of bonding between the fine particles is also easy. Therefore, the bonding material 3 is preferably one containing fine particles of silver or copper for the improvement of bonding reliability and the like.

If the dimension of the gap 8 is, for example, about 10 μm or more in plan view (as viewed from the direction opposite to the upper surface of the line conductor 2), the above-mentioned thermal stress can be effectively relieved. It is easy to place a quantity of bonding material 3 between the end face 1a and the side face 2a. Further, if the gap 8 is, for example, about 100 μm or less in plan view, the distance between the end face 1a of the metal terminal 1 and the side face 2a of the line conductor 2 is such that the entry of the bonding material 3 becomes difficult. The possibility of becoming large can be reduced. That is, it is advantageous for securing the workability and bonding strength of bonding between the metal terminal 1 and the line conductor 2 via the bonding material 3. Therefore, when the gap 8 is set between the end face 1a of the metal terminal 1 and the side surface 2a of the line conductor 2, the dimension of the gap 8 in plan view may be set in the range of about 10 to 100 μm.

The form including such a gap 8 is not limited to the example shown in FIG. For example, the bonding material 3 may be joined from the gap 8 to the lower surface of the metal terminal 1 so as to surround the entire circumference of the metal terminal 1 at the first end 1 b of the metal terminal 1 (that is, annularly The bonding material 3 may be located.

In the example shown in FIG. 1 and FIG. 4, the upper outer periphery of the bonding material 3 is slightly expanded outward. That is, in the vertical cross section, a part of the outer periphery of the bonding material 3 is convex outward. As a result, the amount of bonding material 3 can be made relatively large, and the effects of reduction in conduction resistance and stress relaxation can be enhanced.

The positional relationship between the metal terminal 1 and the line conductor 2 in which the end face 1a and the side face 2a face each other and is joined is not limited to the examples shown in FIGS. For example, the metal terminal 1 may be located below the line conductor 2, and the side surface 2a of the line conductor 2 may be connected to the center of the end face 1a.

However, as in the example shown in FIGS. 1 and 4, for example, the metal terminal 1 and the line conductor 2 are parallel to each other in the length direction, and the metal terminal 1 is located above the line conductor 2, The junction structure C in which the lower portion of the end face 1a of the terminal 1 and the upper portion of the side surface of the line conductor face each other has the following advantages. That is, in this case, since the alignment of the metal terminal 1 with respect to the line conductor 2 can be performed from the upper side, which is the direction in which the line conductor 2 is exposed, the alignment operation is easy and the improvement of the position accuracy is easy. is there. Therefore, it is advantageous to the improvement of the characteristics and productivity as the junction structure C and the semiconductor package 10.

Moreover, in this case, it is also easy to make the bonding material 3 convex outward as described above. Therefore, it is also easy to produce the joint structure C having an advantageous structure in enhancing the effect of stress relaxation.

FIG. 5 is an enlarged cross-sectional view of the main part of a bonded structure C according to still another embodiment of the present invention. In FIG. 5, the same parts as those in FIGS. 1 to 3B are denoted by the same reference numerals. In the example shown in FIG. 5, the lower surface of the metal terminal 1 is located below the line conductor 2 in a cross-sectional view in the vertical direction including the end surface 1 a of the metal terminal 1. The junction structure C and the semiconductor package 10 according to the other embodiment are the same as the junction structure C and the semiconductor package 10 according to the above-described embodiment in other points. The description of these same points will be omitted.

In this case, when the side surface 2 a of the line conductor 2 is made to face the end face 1 a of the metal terminal 1, the line conductor 2 can be made to face a relatively wide range of the end face 1 a. In other words, the strictness of the alignment between the two can be reduced. Therefore, the junction structure C and the semiconductor package 10 including the same can be more easily manufactured.

In this case, the side surface 2a of the line conductor 2 can be brought into direct contact with the end face 1a of the metal terminal 1 to reduce the contact resistance. Also, the fabrication of such direct contact (connection) structures can be facilitated as described above. Therefore, the impedance matching is easy, and it is effective to reduce the conduction resistance, and the junction structure C and the semiconductor package 10 can be effective also for securing the productivity.

FIG. 6 is an enlarged cross-sectional view of the main part of a bonded structure C according to still another embodiment of the present invention. Parts in FIG. 6 similar to those in FIGS. 1 to 3B are assigned the same reference numerals. In the example shown in FIG. 6, similar to the embodiment shown in FIG. 1, the end face 1a of the metal terminal 1 and the side face 2a of the line conductor 2 face each other, and the end face 1a and the side face 2a are in direct contact. Furthermore, the bonding material 3 is positioned to cover the outer periphery of the metal terminal 1 at the first end 1 b of the metal terminal 1. The junction structure C and the semiconductor package 10 according to the other embodiment are the same as the junction structure C and the semiconductor package 10 according to the above-described embodiment in other points. The description of these same points will be omitted.

By the end face 1a and the side face 2a facing each other, a change in resistance in the transmission path caused by the overlapping of the metal terminal 1 and the line conductor 2 is suppressed. On the other hand, as shown in FIG. 1, in the first end portion 1b, if the lower part of the circumferential surface is not covered with the bonding material 3 and there is a portion where air is adjacent to the metal terminal 1, The impedance changes locally. The transmission characteristic of the signal to be transmitted is degraded due to reflection or the like caused by this change. In the present embodiment, since the bonding material 3 is positioned so as to cover the outer periphery of the first end 1b, it is possible to suppress the change in impedance at the first end 1b and to suppress the deterioration of the transmission characteristics. The bonding material 3 covers the outer periphery of a portion of the first end 1 b that protrudes from the first surface 4 a. The bonding material 3 may be covered so as to be in direct contact with the outer periphery.

FIG. 7 is an enlarged cross-sectional view of the main part of a bonded structure C according to still another embodiment of the present invention. The same reference numerals as in FIGS. 1 to 3B denote the same parts in FIG. In the example shown in FIG. 7, among the metal terminals 1, only the end surface 1 a is exposed on the first surface 4 a side of the substrate 4, and the end surface 1 a of the metal terminal 1 and the side surface 2 a of the line conductor 2 are And the end face 1a and the side face 2a are in direct contact with each other. The junction structure C and the semiconductor package 10 according to the other embodiment are the same as the junction structure C and the semiconductor package 10 according to the above-described embodiment in other points. The description of these same points will be omitted. As to the positional relationship in the vertical direction in the present embodiment, the lower surface of the line conductor 2 is lower than the metal terminal 1 in the cross-sectional view in the vertical direction including the end face 1 a of the metal terminal 1 as in the embodiment shown in FIG. Located on the side.

Of the metal terminals 1, only the end surface 1 a is exposed on the first surface 4 a side of the substrate 4, in other words, the first surface 4 a and the end surface 1 a are flush or the length direction of the metal terminal 1 The end surface 1a does not protrude from the first surface 4a. The bonding material 3 is positioned so as to cover from the exposed end surface 1 a to the second end 2 b including the side surface 2 a of the line conductor 2. As described later, in the through holes 4 c of the substrate 4, a sealing material made of an insulating material is located. The sealing material has a function of closing the gap between the metal terminal 1 and the through hole 4c. When only the end face 1a is exposed on the first surface 4a side, the entire periphery of the metal terminal 1 in the through hole 4c of the substrate 4 is covered with the sealing material, and the end face 1a is formed by the bonding material 3 Covered and without air contact. Thus, local changes in impedance can be suppressed, and deterioration of transmission characteristics can be suppressed.

FIG. 8 is an enlarged cross-sectional view of the main parts of a bonded structure C according to still another embodiment of the present invention. In FIG. 8, the same parts as those in FIGS. 1 to 3B are denoted by the same reference numerals. In the example shown in FIG. 8, as in the embodiment shown in FIG. 7, the metal terminal 1 is positioned on the first surface 4 a side of the substrate 4 so that only the end face 1 a is exposed. The end face 1a of the line conductor 2 faces the side face 2a of the line conductor 2, and the end face 1a is in direct contact with the side face 2a. As to the positional relationship in the vertical direction, the lower surface of the metal terminal 1 is positioned lower than the line conductor 2 in the vertical cross-sectional view including the end face 1a of the metal terminal 1 as in the embodiment shown in FIG. There is. The junction structure C and the semiconductor package 10 according to the other embodiment are the same as the junction structure C and the semiconductor package 10 according to the above-described embodiment in other points. The description of these same points will be omitted.

Moreover, in the example of each of the above embodiments including the other embodiments, the bonding material 3 extends continuously from the first end 1 b of the metal terminal 1 to a portion adjacent to the side surface of the top surface 2 bb of the line conductor 2. You may be doing what you are doing. In this case, since the bonding material 3 spreads over a relatively wide range and is bonded to the line conductor 2, it is effective to improve the bonding strength between the bonding material 3 and the line conductor 2. In addition, the bonding strength between the metal terminal 1 and the line conductor 2 through the bonding material 3 can also be effectively improved.

In this case, the tip of the portion of the bonding material 3 bonded to the top surface 2 bb to the line conductor 2 may have a shape that does not have corner portions such as arcs or elliptical arcs in a plan view, for example. In this case, the possibility of peeling of the bonding material starting from the corner portion can be effectively reduced. Therefore, the bonding strength between the metal terminal 1 and the line conductor 2 through the bonding material 3 can be effectively improved.

In each of the above examples, when the metal particles are silver particles, the following advantages are obtained. That is, it is advantageous for reducing the electrical resistance in the transmission line of the signal including the line conductor 2 and the metal terminal 1, such as the thermal conductivity of the bonding material 3 (that is, the heat dissipation of the bonding structure C and the semiconductor package 10 including this It is. Moreover, it is hard to remelt also in the heat load process for mounting of a semiconductor element, joining of a metal case, etc., and the advantage of having few outgasses is mentioned.

The silver particles in this case may be so-called pure silver containing 99.9% by mass or more of silver, or may contain other components such as a trace amount of copper or gold. In addition, all the metal particles may not be silver particles, and for example, both silver particles and copper particles may be contained in the metal particles.

In addition, when the metal particles are copper particles or contains copper particles, the possibility of ion migration is reduced, economic efficiency is improved, etc., as compared to when all the metal particles are silver particles. Is advantageous.

As described above, the semiconductor package of the embodiment of the present invention has the following configuration. That is, the semiconductor package 10 of the present embodiment includes the substrate 4 having the first surface 4 a and the second surface 4 b opposite to the first surface 4 a, the line conductor 2 positioned on the first surface 4 a side of the substrate 4, and the substrate 4 includes a metal terminal 1 penetrating from the second surface 4b to the first surface 4a and having an end 1b on the first surface 4a side, and metal particles; the end of the metal terminal 1 (first end And a bonding material 3 interposed between the line conductor 2 and the portion 1b. In addition, the semiconductor package 10 of the present embodiment includes the junction structure C of any of the above-described configurations between the end portion 1 b of the metal terminal 1 and the line conductor 2.

According to the semiconductor package 10 of the above embodiment, since the junction structure C of any of the above configurations is provided, impedance matching in the transmission line of the signal formed of the metal terminal 1 and the line conductor 2 is easy, and high frequency signal The semiconductor package 10 effective for improving the transmission characteristics of

The first surface 4 a side of the substrate 4 is a side sealed with the above-described metal case. The end 1 b of the semiconductor element and the metal terminal 1 is sealed in the space formed between the substrate 4 and the metal case. Further, in the examples shown in FIGS. 2A, 2B, 3A, 3B, etc., the sealing material (without the reference numeral) is located in the through hole 4c of the substrate 4. The sealing material has a function of closing the gap between the metal terminal 1 and the through hole 4c. The sealing material is made of an insulating material such as a glass material or a ceramic material. Examples of such an insulating material include glasses such as borosilicate glass and soda glass, and those obtained by adding a ceramic filler for adjusting the thermal expansion coefficient and the relative dielectric constant to these glasses. This insulating material can be appropriately selected in consideration of impedance matching (relative dielectric constant) in the metal terminal 1 and reliability of sealing. In FIGS. 1, 4 and 5, the sealing material between the metal terminal 1 and the through hole 4 c of the substrate 5 is omitted.

The submount 6 is provided on the first surface 4 a of the substrate 4 and has a substrate mounting surface perpendicular to the first surface 4 a. In the semiconductor package 10, the submount 6 has a function of conducting heat generated by the electronic component mounted on the insulating plate 5 to the substrate 4 and the like. That is, the submount 6 has a function as a heat dissipation material that dissipates heat to the outside of the semiconductor package 10.

The submount 6 may be integrally formed with the substrate 4 and may include a cooling member (eg, a Peltier element or the like). When the submount 6 is integrally formed with the substrate 4, the submount 6 is made of the same metal material as the substrate 4. Thereby, the heat dissipation in the semiconductor package 10 is effectively ensured.

FIG. 9 is a perspective view of a semiconductor device according to an embodiment of the present invention. The semiconductor device of the embodiment of the present invention has the following configuration. That is, the semiconductor device 100 of the present embodiment includes the semiconductor package 10 and the semiconductor element 20 located on the first surface 4 a side of the substrate 4 and electrically connected to the line conductor 2. The semiconductor element 20 is, for example, an optical semiconductor element or the like as described above. The semiconductor element 20 is mounted on the insulating plate 5 and electrically connected to the line conductor 2 by a bonding wire or solder.

According to the semiconductor device 100 of the above embodiment, since the semiconductor package 10 having any one of the above configurations is provided, it is possible to provide the semiconductor device 100 in which impedance matching is easy and the transmission characteristics of high frequency signals are improved.

The present invention is not limited to the examples of the embodiments described above, and various modifications are possible within the scope of the present invention.

For example, the end face 1a of the metal terminal 1 does not have to be exactly perpendicular to the upper surface 2bb of the line conductor 2, but may be slightly (about several degrees) inclined according to processing accuracy and the like.

The high frequency signal characteristics of the bonded structure (first structure) of the embodiment shown in FIG. 1 and the bonded structure (second structure) of the embodiment shown in FIG. 8 were simulated and compared. The difference between the first structure and the second structure is that the first structure has a structure in which the first end 1b of the metal terminal 1 protrudes from the first surface 4a of the substrate 4, and the second structure However, the first end 1 b of the metal terminal 1 does not protrude from the first surface 4 a of the substrate 4.

10A and 10B show simulation models, FIG. 10A shows a first structure model A, and FIG. 10B shows a second structure model B. FIG. In the first structure model A, the first end 1 b of the metal terminal 1 protrudes 50 μm from the first surface 4 a of the substrate 4. In the second structure model B, the first end 1 b of the metal terminal 1 does not protrude from the first surface 4 a of the substrate 4, and only the end surface 1 a is exposed on the first surface 4 a side of the substrate 4. The configuration is located and corresponds to the model of the embodiment shown in FIG. 8 of the present invention.

10C and 10D show simulation results, and FIG. 10C shows reflection loss (S11) and FIG. 10D shows insertion loss (S21). The reflection loss and the insertion loss are calculation results obtained by S parameter analysis. The result of the first structure model A is shown by a broken line, and the result of the second structure model B is shown by a solid line. The smaller the value (dB) on the vertical axis (the lower side of the graph), the smaller the return loss, indicating that the transmission characteristics are better. The insertion loss is such that the value (dB) on the vertical axis is closer to zero ( The higher the graph, the smaller the loss, indicating that the transmission characteristics are better. As shown in FIG. 10C, in the reflection loss, the higher the frequency, the larger the difference between the first structure model A and the second structure model B, and the second structure model B exhibited better characteristics. . As shown in FIG. 10D, in the insertion loss, the second structure model B exhibited slightly better characteristics.

The present invention can be practiced in various other forms without departing from its spirit or main features. Accordingly, the above-described embodiments are merely illustrative in every respect, and the scope of the present invention is as set forth in the claims, and is not limited by the text of the specification. Furthermore, all variations and modifications that fall within the scope of the claims fall within the scope of the present invention.

1 · · Metal terminal 1a · · End face 1b · · First end 2 · · Line conductor 2a · · Side 2b · · Second end 2bb · · · (Top of line conductor) 3 · · Bonding material 4 · · · 4a · · First surface 4b · · Second surface 4c · · Through hole 5 · · Insulating plate 6 · · Submount 7 · · Ground terminal 8 · · Gap
10 ・・ Semiconductor package
20 · · Semiconductor device
100 · · Semiconductor device C · · Junction structure

Claims

A metal terminal having an end face,
A line conductor having side surfaces on which a part of the end face of the metal terminal is opposed;
A junction structure including a metal particle and being disposed so as to cover from the end face of the metal terminal to a part of the line conductor, and joined to the metal terminal and the line conductor. body.
The junction structure according to claim 1, wherein the end surface of the metal terminal and the side surface of the line conductor are separated from each other.
The metal terminal and the line conductor are parallel to each other in the length direction, and the metal terminal is located above the line conductor, and a lower portion of the end surface of the metal terminal and the side surface of the line conductor The joined structure according to claim 1 or 2, wherein the upper portions of the two face each other face each other.
The joint structure according to claim 3, wherein a lower end of the metal terminal is positioned lower than the line conductor in a cross-sectional view in the vertical direction including the end surface of the metal terminal.
The joint structure according to claim 3, wherein the bonding material is continuously located from the end surface of the metal terminal to a portion adjacent to the side surface of the top surface of the line conductor.
The bonding structure according to any one of claims 1 to 5, wherein the bonding material is positioned to cover an outer periphery of a first end including the end surface of the metal terminal.
The bonded structure according to any one of claims 1 to 6;
A substrate having a first surface and a second surface opposite to the first surface;
The line conductor is located on the first surface side of the substrate,
The semiconductor package, wherein the metal terminal penetrates from the second surface to the first surface of the substrate and has an end face on the first surface side.
The semiconductor package according to claim 7, wherein the first surface and the end surface are flush with each other, or the end surface does not protrude from the first surface when viewed in the length direction of the metal terminal.
A semiconductor package according to claim 7 or 8,
A semiconductor element located on the first surface side and electrically connected to the line conductor.