Stem for semiconductor package, method of manufacturing stem for semiconductor package, and semiconductor package

Abstract

To improve a heat dissipation property of a stem for a semiconductor package.SOLUTION: A stem for a semiconductor package comprises: an eyelet comprising a through hole including a first hole part and a second hole part which communicates to the first hole part and of which the inner diameter is larger than that of the first hole part; a lead which is disposed inside of the through hole; a sealing member which is disposed between an inner side face of the first hole part and a side face of the lead and extends to the side of the second hole part; and a fitting member which is disposed between an inner side face of the second hole part and an outer side face of the sealing member. The fitting member has rigidity which is higher than that of the eyelet, and a thermal expansion coefficient of the fitting member is larger than a thermal expansion coefficient of the sealing member and smaller than a thermal expansion coefficient of the eyelet.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a stem for a semiconductor package, a method for manufacturing a stem for a semiconductor package, and a semiconductor package. [Background technology]

[0002] In a stem for a semiconductor package that mounts a semiconductor element such as a light-emitting element, a structure is known in which a through hole is formed in a disk-shaped eyelet made of iron or the like, and a lead is hermetically sealed within the through hole with a sealing material.

[0003] Furthermore, in order to improve the heat dissipation of the stem for a semiconductor package, copper or other materials are sometimes used instead of iron or other materials as the material for the eyelet. However, copper has lower rigidity than iron, so there is a risk that the airtightness between the eyelet and the lead may be reduced. This is because if the eyelet has low rigidity, it is not possible to apply sufficient stress to the sealing material.

[0004] In order to solve this problem, a structure has been proposed in which a bush having higher rigidity than the eyelet is interposed between the eyelet and the sealing member (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-100535 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since the bushing described in Patent Document 1 is provided over the entire thickness of the eyelet, the diameter of the through-hole must be increased to accommodate the bushing, which reduces the heat dissipation surface area of the eyelet and prevents sufficient heat dissipation.

[0007] The present invention has been made in view of the above points, and has as its object to improve the heat dissipation properties of a stem for a semiconductor package. [Means for solving the problem]

[0008] This stem for a semiconductor package comprises an eyelet having a through hole including a first hole portion and a second hole portion communicating with the first hole portion and having an inner diameter larger than that of the first hole portion, a lead arranged in the through hole, a sealing material arranged between the inner surface of the first hole portion and a side surface of the lead and extending toward the second hole portion, and an embedding member arranged between the inner surface of the second hole portion and the outer surface of the sealing material, wherein the embedding member has higher rigidity than the eyelet, and the thermal expansion coefficient of the embedding member is greater than that of the sealing material and less than that of the eyelet. [Effects of the Invention]

[0009] According to the disclosed technology, the heat dissipation performance of the stem for semiconductor package can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are diagrams (part 1) illustrating a stem for a semiconductor package according to the first embodiment; [Figure 2] 4A and 4B are diagrams (part 2) illustrating the stem for a semiconductor package according to the first embodiment; [Figure 3] 10 is a diagram (part 3) illustrating the stem for a semiconductor package according to the first embodiment. FIG. [Figure 4] 3A to 3C are cross-sectional views illustrating a manufacturing process of the stem for a semiconductor package according to the first embodiment. [Figure 5] 1A and 1B are diagrams showing an example in which plating is used for a metal joining material. [Figure 6] 10 is a cross-sectional view illustrating a stem for a semiconductor package according to a first modified example of the first embodiment. FIG. [Figure 7] 10A and 10B are diagrams illustrating a stem for a semiconductor package according to a second modified example of the first embodiment. [Figure 8] FIG. 10 is a cross-sectional view illustrating a semiconductor package according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0012] First Embodiment Fig. 1 is a diagram (part 1) illustrating a stem for a semiconductor package according to the first embodiment, where Fig. 1(a) is a plan view and Fig. 1(b) is a bottom view. Fig. 2 is a diagram (part 2) illustrating a stem for a semiconductor package according to the first embodiment, where Fig. 2(a) is a perspective view from the top side and Fig. 2(b) is a perspective view from the bottom side. Fig. 3 is a diagram (part 3) illustrating a stem for a semiconductor package according to the first embodiment, where Fig. 3(a) is a cross-sectional view taken along line AA in Fig. 1(a) and Fig. 3(b) is a perspective cross-sectional view taken along line AA in Fig. 1(a).

[0013] 1 to 3, a stem for a semiconductor package 1 according to the first embodiment includes an eyelet 10, a metal block 20, leads 31, 32, a sealing member 40, and a fitting member 50. As shown in FIG.

[0014] The eyelet 10 is a disk-shaped member. In this application, disk-shaped refers to a member that has a roughly circular planar shape and a predetermined thickness. The thickness may be large or small relative to the diameter. This also includes members that have partial recesses, protrusions, through holes, etc. formed therein. In this application, a planar view refers to viewing an object from the normal direction of the top surface 10a of the eyelet 10, and a planar shape refers to the shape of the object viewed from the normal direction of the top surface 10a of the eyelet 10.

[0015] The diameter of the eyelet 10 is not particularly limited and can be determined appropriately depending on the purpose, for example, φ5.6 mm, φ9.0 mm, etc. The thickness of the eyelet 10 is not particularly limited and can be determined appropriately depending on the purpose, for example, approximately 1.0 mm to 2.0 mm. The eyelet 10 is made of a metal material such as copper or a copper alloy. The surface of the eyelet 10 may be plated.

[0016] The outer edge of the eyelet 10 is formed with cutouts 11, 12, and 13 that are recessed from the outer periphery toward the center in a plan view. The cutouts 11, 12, and 13 are, for example, recesses with a substantially triangular or rectangular planar shape. The cutouts 11 and 12 can be arranged, for example, facing each other.

[0017] The cutouts 11 and 12 can be used, for example, to position the element mounting surface when a semiconductor element is mounted on the semiconductor package stem 1. The cutout 13 can be used, for example, to position the semiconductor package stem 1 in the rotational direction. However, the cutouts 11, 12, and 13 may be provided as needed.

[0018] The eyelet 10 has a through hole 15 that penetrates from the upper surface 10a to the lower surface 10b. The through hole 15 includes a first hole portion 16 and a second hole portion 17 that communicates with the first hole portion 16 and has a larger inner diameter than the first hole portion 16. The first hole portion 16 opens to the upper surface 10a of the eyelet 10, and the second hole portion 17 opens to the lower surface 10b of the eyelet 10. The first hole portion 16 and the second hole portion 17 can be formed concentrically. The hole diameter of the first hole portion 16 is, for example, about 1.0 mm to 1.2 mm, and the hole diameter of the second hole portion 17 is, for example, about 1.5 mm to 2.5 mm. The depth of the first hole portion 16 is, for example, about 0.8 mm to 1.3 mm, and the depth of the second hole portion 17 is, for example, about 0.2 mm to 0.7 mm.

[0019] The metal block 20 is a columnar member having a substantially semicircular planar shape. The metal block 20 is disposed on the upper surface 10a of the eyelet 10. The amount by which the metal block 20 protrudes from the upper surface 10a of the eyelet 10 is, for example, approximately 2 to 3 mm. The metal block 20 can be formed, for example, from the same material as the eyelet 10. The metal block 20 may be formed integrally with the eyelet 10, or may be a separate piece joined with brazing material or the like.

[0020] The metal block 20 is the portion on which the semiconductor element is mounted and fixed when the semiconductor package stem 1 is used as a semiconductor package equipped with the semiconductor element, and also functions as a heat sink that dissipates heat generated by the semiconductor element. The portion of the metal block 20 protruding from the upper surface 10a of the eyelet 10 includes an element mounting surface 20r on which a semiconductor element (e.g., a light-emitting element such as a laser) is mounted. The element mounting surface 20r is arranged so as to be approximately perpendicular to the upper surface 10a of the eyelet 10.

[0021] The leads 31 and 32 are arranged in the through-hole 15 with their longitudinal direction facing the thickness direction of the eyelet 10. Portions of the leads 31 and 32 protrude from the upper surface 10a and lower surface 10b of the eyelet. The leads 31 and 32 may be cylindrical with a diameter of approximately 0.3 to 1.0 mm, for example. The leads 31 and 32 may be formed from a metal such as a 50% iron-nickel alloy or Kovar.

[0022] The sealing material 40 is disposed within the through-hole 15. Specifically, the sealing material 40 is disposed between the inner surface of the first hole 16 and the side surfaces of the leads 31 and 32, and extends toward the second hole 17. The upper surface of the sealing material 40 can be flush with the upper surface 10a of the eyelet 10, for example. The sealing material 40 can be made of glass, such as soft glass. The fusion temperature of the glass is, for example, 900°C or higher.

[0023] The fitting member 50 is disposed between the inner surface of the second hole portion 17 and the outer surface of the sealing member 40. The thickness of the fitting member 50 is slightly thinner than the depth of the second hole portion 17. The fitting member 50 is joined to the second hole portion 17, for example, by a metal joining material having a melting point of 900°C or higher. An example of such a metal joining material is a brazing material containing high-purity silver. Here, "containing high-purity silver" means that the silver content is 95% by weight or more. The lower surface of the fitting member 50 can be flush with the lower surface of the sealing member 40 and the lower surface 10b of the eyelet 10, for example.

[0024] The fitting member 50 has higher rigidity than the eyelet 10. The thermal expansion coefficient of the fitting member 50 is greater than that of the sealing member 40 and less than that of the eyelet 10. For example, if the sealing member 40 is made of glass and the eyelet is made of copper or a copper alloy, the fitting member 50 can be made of iron or an iron alloy (for example, steel or stainless steel). The thermal expansion coefficient of glass is, for example, 9.4×10 -6 The thermal expansion coefficient of copper is, for example, 17.7 × 10 -6 The thermal expansion coefficient of iron is, for example, 13.5 × 10 -6 That's about it.

[0025] In this way, in the stem 1 for semiconductor package, the fitting member 50 is fixed in the second hole portion 17 provided in the eyelet 10, and the leads 31 and 32 are arranged approximately on the center line of the sealing member 40 and the fitting member 50. The leads 31 and 32 are airtightly sealed in the through hole 15 provided in the eyelet 10. Note that since the sealing member 40 is made of an insulating material, the leads 31 and 32 are insulated from the eyelet 10.

[0026] Since the fitting member 50 is provided only on the lower surface 10b side of the eyelet 10, the area of the upper surface 10a is the same as the area of the upper surface 10a of the eyelet 10 when the fitting member 50 is not provided. Since the area of the upper surface 10a of the eyelet 10 can be maintained even when the fitting member 50 is provided, the heat dissipation performance of the stem 1 for semiconductor packages can be improved compared to the structure of Patent Document 1.

[0027] [Method for manufacturing stem 1 for semiconductor package] 4A to 4C are cross-sectional views illustrating a manufacturing process of the stem for a semiconductor package according to the first embodiment.

[0028] 4(a), for example, an eyelet 10, leads 31 and 32, a hollow sealing member 40 made of glass such as soft glass, a hollow fitting member 50, and a hollow metal bonding material 60 having a melting point of 900°C or higher are prepared. A material having a higher rigidity than the eyelet 10 is selected for the fitting member 50. In addition, a material is selected such that the thermal expansion coefficient of the fitting member 50 is greater than that of the sealing member 40 and less than that of the eyelet 10.

[0029] The eyelet 10 has a through hole 15 including a first hole portion 16 and a second hole portion 17 that communicates with the first hole portion 16 and has an inner diameter larger than that of the first hole portion 16. The eyelet 10 can be manufactured, for example, by a cold forging press or the like. The eyelet 10 may also include a metal block 20. When the eyelet 10 and the metal block 20 are separate bodies, for example, the eyelet 10 can be formed by a cold forging press or the like, and the metal block 20 can be joined to the upper surface 10a of the eyelet 10 by brazing or the like.

[0030] The leads 31 and 32 can be produced, for example, by cutting a drawn wire material. The sealing member 40 can be produced, for example, by forming glass powder into a cylindrical shape by powder molding, heating the cylindrically formed glass powder particles to a degree that they fuse together, and then cooling. The fitting member 50 can be produced, for example, by pressing or etching.

[0031] 4(b), the metal bonding material 60 and the fitting member 50 are inserted in this order into the second hole portion 17 of the eyelet 10, the sealing member 40 is inserted into the first hole portion 16, the metal bonding material 60, and the fitting member 50, and the leads 31 and 32 are inserted into the sealing member 40. The order of inserting the metal bonding material 60 and the fitting member 50 and the order of inserting the sealing member 40 may be reversed.

[0032] 4(c), the sealing material 40 and the metal bonding material 60 are heated to, for example, about 1000°C to melt them, and then solidified. As a result, the inner surface of the first hole 16 is sealed to the side surfaces of the leads 31 and 32, and the inner surface of the fitting member 50 is sealed to the side surfaces of the leads 31 and 32 by the sealing material 40, and the inner surface of the second hole 17 is joined to the outer surface of the fitting member 50 by the metal bonding material 60. The metal bonding material 60 melts and flows between the inner surface of the second hole 17 and the outer surface of the fitting member 50, brazing them together. This completes the semiconductor package stem 1.

[0033] In this step, a material having a larger thermal expansion coefficient than the sealing material 40 and the leads 31 and 32 is used as the fitting member 50. Therefore, when the sealing material 40 and the metal bonding material 60 are solidified, the leads 31 and 32 can be hermetically sealed in the fitting member 50 via the sealing material 40 by using the thermal contraction force of the fitting member 50, which has a larger thermal expansion coefficient than the sealing material 40 and the leads 31 and 32.

[0034] The melting point of the metal joining material 60 is preferably 900°C or higher. Examples of such materials include brazing materials containing high-purity silver. When the sealing member 40 is made of glass, the fusion temperature is 900°C or higher. By setting the melting point of the metal joining material 60 to 900°C or higher, glass fusion and silver brazing can be performed simultaneously with a single heating operation. Furthermore, if the melting point of the metal joining material 60 is lower than 900°C, the fluidity of the molten metal joining material 60 becomes too high, which may result in the metal joining material 60 flowing into regions other than those intended for joining, or the metal joining material 60 not remaining in the joint, resulting in insufficient joining or in an inability to maintain airtightness. Setting the melting point of the metal joining material 60 to 900°C or higher can reduce such risks.

[0035] Thus, in the semiconductor package stem 1, the leads 31 are sealed by the sealing material 40 to the inside of the annular fitting member 50, which is made of a material with higher rigidity than the eyelet 10. The fitting member 50 is also made of a material with a higher thermal expansion coefficient than the sealing member 40. This allows the fitting member 50 to apply sufficient stress to the sealing member 40, so that the leads 31 can be fixed to the fitting member 50 in an airtight manner.

[0036] That is, in order to improve heat dissipation, eyelet 10 may be made of copper, copper alloy, or the like, but copper and copper alloy are materials with lower rigidity than the iron and iron alloys that have been used conventionally. Even in such cases, by using an annular fitting member 50 made of a material that is more rigid than eyelet 10, such as iron or iron alloy, and has a higher thermal expansion coefficient than sealing member 40, fitting member 50 can apply sufficient stress to sealing member 40. As a result, airtightness between eyelet 10 and lead 31 can be ensured. The same applies to airtightness between eyelet 10 and lead 32.

[0037] Furthermore, wires are connected to the leads 31 and 32, and the eyelet 10 is also heated at this time. If the eyelet 10 is made of a low-rigidity material such as copper or a copper alloy, without the fitting member 50, the compression force is released when the eyelet 10 is heated, and the eyelet 10 does not return to its original shape, which may cause the leads 31 and 32 to come out of the eyelet 10 together with the sealing member 40. By providing the fitting member 50, which has higher rigidity than the eyelet 10, the compression force can be maintained even when the eyelet 10 is heated, and therefore the leads 31 and 32 can be prevented from coming out of the eyelet 10 together with the sealing member 40.

[0038] Furthermore, the semiconductor package stem 1 has an easy-to-manufacture structure. Specifically, the bushing in Patent Document 1 has a complex shape with a flange, making it difficult to manufacture and limiting its mass-producibility. In contrast, the fitting member 50 constituting the semiconductor package stem 1 is disposed only in the second hole 17, and therefore does not have a stepped portion on its outer periphery like the flange in Patent Document 1. This facilitates manufacturing. Furthermore, because the melting point of the metal bonding material 60 is set to 900°C or higher, the sealing of the leads 31 and 32 with the sealing material 40 and the bonding of the eyelet 10 to the fitting member 50 with the metal bonding material 60 can be completed with a single assembly step shown in FIG. 4(b) and a single heating step shown in FIG. 4(c). This shortens the manufacturing time of the semiconductor package stem 1. Note that, as in the past, using a metal member with a low melting point may require multiple heating steps.

[0039] 4(a), a hollow fitting member 50 may be prepared, as shown in FIG. 5, having a surface coated with plating 60A as a metal bonding material. The plating 60A preferably contains a metal having a melting point of 900°C or higher. Examples of such materials include high-purity silver plating. In this case, the sealing member 40 and the plating 60A are heated to melt and then solidified. This allows the sealing member 40 to seal the inner surface of the first hole 16 to the side surfaces of the leads 31 and 32, and the inner surface of the fitting member 50 to the side surfaces of the leads 31 and 32, and also the inner surface of the fitting member 50 to the side surfaces of the leads 31 and 32. Furthermore, the plating 60A can be used to join (braze) the inner surface of the second hole 17 to the outer surface of the fitting member 50.

[0040] <Modification 1 of the First Embodiment> Modification 1 of the first embodiment shows an example in which the shape of the through holes is different from that of Embodiment 1. Note that in Modification 1 of the first embodiment, the description of the same components as those in the already described embodiments may be omitted.

[0041] 6 is a cross-sectional view illustrating a stem for a semiconductor package according to Modification 1 of the first embodiment. Referring to FIG. 6, the stem for a semiconductor package 1A differs from the stem for a semiconductor package 1 in that the through hole 15 is replaced with a through hole 15A.

[0042] Through hole 15A is similar to through hole 15 in that it penetrates from the upper surface 10a to the lower surface 10b of eyelet 10. However, through hole 15A has the opposite positional relationship between first hole portion 16 and second hole portion 17 to through hole 15. That is, in through hole 15A, second hole portion 17 opens to the upper surface 10a of eyelet 10, and first hole portion 16 opens to the lower surface 10b of eyelet 10.

[0043] In this way, the positional relationship between the first hole 16 and the second hole 17 may be such that either one opens toward the upper surface 10a of the eyelet 10. When the second hole 17, which has a larger inner diameter than the first hole 16, opens toward the upper surface 10a of the eyelet 10, as in the case of the through hole 15A, the area of the lower surface 10b is the same as the area of the lower surface of the eyelet when the fitting member 50 is not provided. This allows the semiconductor package stem 1 to have improved heat dissipation compared to the structure of Patent Document 1. In particular, when a heat sink or the like is attached to the lower surface 10b of the eyelet 10, the contact area between the lower surface 10b of the eyelet 10 and the heat sink or the like is increased, which is advantageous in terms of improving heat dissipation.

[0044] <Modification 2 of the First Embodiment> In the second modification of the first embodiment, an example in which a seal portion is provided on the upper surface of the eyelet is shown. Note that in the second modification of the first embodiment, the description of the same components as those in the already described embodiments may be omitted.

[0045] 7A and 7B are diagrams illustrating a stem for a semiconductor package according to a second modification of the first embodiment, in which Fig. 7A is a plan view and Fig. 7B is a cross-sectional view taken along line BB in Fig. 7A. Referring to Fig. 7, the stem for a semiconductor package 1B differs from the stem for a semiconductor package 1 in that a sealing portion 70 is added.

[0046] The seal portion 70 is arranged in an annular shape on the upper surface 10a of the eyelet 10 so as to surround the metal block 20 and the leads 31 and 32. The seal portion 70 has, for example, a substantially circular annular shape in a plan view. The seal portion 70 can be joined to the upper surface 10a of the eyelet 10 by brazing using a brazing material such as silver brazing. In this case, by using a brazing material containing high-purity silver, the fusion of the sealing member 40, the brazing of the fitting member 50, and the brazing of the seal portion 70 can be performed simultaneously by a single heating process.

[0047] The seal portion 70 can be used when attaching a cap to the semiconductor package stem 1B. The cap is joined to the eyelet 10 by, for example, resistance welding. When resistance welding is performed, it is preferable to use a material for the seal portion 70 that has a higher resistivity than the material (e.g., copper) that constitutes the eyelet 10, that is, a material that is more suitable for resistance welding than the material that constitutes the eyelet 10. Examples of such materials include iron and iron alloys (e.g., Kovar).

[0048] In the case of a stem for a semiconductor package that does not require a cap, the sealing portion 70 does not need to be provided.

[0049] Second Embodiment The second embodiment shows an example of a semiconductor package using a stem for a semiconductor package according to Modification 2 of the first embodiment. Note that in the second embodiment, descriptions of the same components as those in the already described embodiments may be omitted.

[0050] 8 is a cross-sectional view illustrating a semiconductor package according to the second embodiment. Referring to FIG. 8, the semiconductor package 2 includes a semiconductor package stem 1B, a light emitting element 110, a cap 120, an adhesive 130, and a transparent member 140.

[0051] The light emitting element 110 is, for example, a semiconductor laser chip with a wavelength of 405 nm, 650 nm, or 780 nm. The light emitting element 110 is fixed to the element mounting surface 20r of the metal block 20 so that one end face faces upward (toward the transparent member 140) and the other end face faces downward (toward the upper surface 10a of the eyelet 10). In the semiconductor package 2, the light emitting element 110 is mounted so that, for example, in a plan view, the light emitting point position of the light emitting element 110 substantially coincides with the center of the upper surface 10a of the eyelet 10. The electrodes of the light emitting element 110 are electrically connected to the leads 31 and 32, for example, by bonding wires or the like.

[0052] Cap 120 is made of a metal such as iron or copper, and has an opening 120x that serves as a window at approximately the center in a plan view. Transparent member 140 is made of glass, for example, and is adhered to the surface of cap 120 on the eyelet 10 side (inner surface) with adhesive 130 made of low-melting-point glass or the like so as to close opening 120x.

[0053] The cap 120 has an annular flange 125 whose outer periphery is bent and protrudes outward. The cap 120, to which the transparent member 140 is adhered with adhesive 130, is joined to the eyelet 10 by joining the lower surface of the flange 125 onto the seal portion 70. This allows the light emitting element 110 fixed to the metal block 20 to be hermetically sealed in the space formed by the cap 120 and the eyelet 10.

[0054] Light (e.g., laser light) emitted from one end surface of the light emitting element 110 passes through the transparent member 140 in the opening 120x and is emitted to the outside of the semiconductor package 2. Note that the light emitted from the other end surface of the light emitting element 110 may be received by a photodiode or the like to monitor the amount of light emitted from the light emitting element 110. By controlling the amount of light received by the photodiode to be constant using a circuit arranged outside the semiconductor package 2, the amount of light emitted from the semiconductor package 2 can be kept constant regardless of the ambient temperature, etc.

[0055] In this way, the semiconductor package 2 can be realized by mounting the light emitting element 110 on the element mounting surface 20r of the stem 1B for semiconductor package. In the stem 1B for semiconductor package, the eyelet 10 is made of copper or a copper alloy, which has high thermal conductivity, and therefore can efficiently dissipate heat generated from the light emitting element 110 fixed to the metal block 20. As a result, even when a high-output light emitting element 110 is used, the temperature rise of the light emitting element 110 can be suitably suppressed.

[0056] Furthermore, the stem for semiconductor package 1B has a seal portion 70 made of a material (e.g., iron or an iron alloy) having a higher resistivity than the material (e.g., copper or a copper alloy) constituting the eyelet 10 on the upper surface 10a of the eyelet 10. This allows the cap 120 to be easily resistance-welded onto the seal portion 70 even if the eyelet 10 is made of copper or a copper alloy, which is difficult to resistance-weld.

[0057] In the second embodiment, an example in which the light-emitting element 110 is mounted on the stem 1B for semiconductor package is shown, but the present invention is not limited to this, and a heat-generating semiconductor element other than a light-emitting element may be mounted on the stem 1 or 1A for semiconductor package. Also, a semiconductor package in which a semiconductor element is mounted on the stem 1, 1A, or 1B for semiconductor package may be used for various sensors, inflators, etc.

[0058] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0059] 1,1A,1B Stem for semiconductor package 2. Semiconductor Package 10 eyelets 10a top surface 10b Bottom side 11, 12, 13 Notch 15,15A through hole 16 1st hole 17 2nd hole 20 Metal Block 20r Element mounting surface 31,32 Lead 40 Sealing material 50 Inserted parts 60 Metal bonding materials 60A plating 70 Seal part 110 Light-emitting element 120 Cap 120x aperture 125 flange 130 Adhesive 140 Transparent materials

Claims

1. an eyelet having a through hole including a first hole portion and a second hole portion communicating with the first hole portion and having an inner diameter larger than that of the first hole portion; a lead disposed in the through hole; a sealing material disposed between an inner surface of the first hole and a side surface of the lead and extending toward the second hole; a fitting member disposed between an inner surface of the second hole portion and an outer surface of the sealing member, the fitting member has a higher rigidity than the eyelet; The stem for a semiconductor package, wherein the coefficient of thermal expansion of the fitting member is greater than the coefficient of thermal expansion of the sealing member and less than the coefficient of thermal expansion of the eyelet.

2. the sealing material is made of glass, 2. The stem for a semiconductor package according to claim 1, wherein the fitting member is joined to the second hole portion by a metal joining material having a melting point of 900[deg.] C. or higher.

3. 3. The semiconductor package stem according to claim 2, wherein the metal bonding material contains high-purity silver.

4. the eyelet is made of copper or a copper alloy; 4. The stem for a semiconductor package according to claim 1, wherein the fitting member is made of iron or an iron alloy.

5. a metal block is placed on the top surface of the eyelet; the first hole portion opens to an upper surface of the eyelet, The stem for a semiconductor package according to claim 1 , wherein the second hole opens to a lower surface of the eyelet.

6. a metal block is placed on the top surface of the eyelet; the second hole portion opens to an upper surface of the eyelet, The stem for a semiconductor package according to claim 1 , wherein the first hole opens to a lower surface of the eyelet.

7. 7. The stem for a semiconductor package according to claim 5, further comprising a sealing portion disposed on an upper surface of the eyelet in a ring shape so as to surround the metal block and the leads in a plan view.

8. The semiconductor package stem according to claim 7 ; a semiconductor element fixed to the metal block and electrically connected to the leads; a cap joined onto the sealing portion.

9. a step of preparing an eyelet having a through hole including a first hole portion and a second hole portion communicating with the first hole portion and having an inner diameter larger than that of the first hole portion, a lead, a hollow sealing member made of glass, a hollow fitting member, and a hollow metal bonding material having a melting point of 900°C or higher; a step of inserting the metal bonding material and the fitting member into the second hole portion in this order, inserting the sealing member into the first hole portion, the metal bonding material, and the fitting member, and inserting the lead into the sealing member; a step of heating and melting the sealing material and the metal bonding material, and then solidifying them to seal the inner surface of the first hole portion and the side surface of the lead, and the inner surface of the fitting member and the side surface of the lead with the sealing material, and joining the inner surface of the second hole portion and the outer surface of the fitting member with the metal bonding material, the fitting member has a higher rigidity than the eyelet; A method for manufacturing a stem for a semiconductor package, wherein the thermal expansion coefficient of the fitting member is greater than that of the sealing member and less than that of the eyelet.

10. a step of preparing an eyelet having a through hole including a first hole portion and a second hole portion communicating with the first hole portion and having an inner diameter larger than that of the first hole portion, a lead, a hollow sealing member made of glass, and a hollow fitting member having a surface plated with a metal bonding material containing a metal having a melting point of 900°C or higher; a step of heating and melting the sealing material and the plating, and then solidifying the sealing material to seal the inner surface of the first hole portion and the side surface of the lead, and the inner surface of the fitting member and the side surface of the lead with the sealing material, and joining the inner surface of the second hole portion and the outer surface of the fitting member with the plating, the fitting member has a higher rigidity than the eyelet; A method for manufacturing a stem for a semiconductor package, wherein the thermal expansion coefficient of the fitting member is greater than that of the sealing member and less than that of the eyelet.

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