Socket for semiconductor package

Abstract

A socket for semiconductor package which suppresses warping of an object to which a lid is joined. The socket for semiconductor package has a board, a frame which is located on the outer periphery side of the board in plan view and is joined to the board, and a lead terminal which is held in a state of being insulated from the board and the frame, the board projecting from the upper surface and the lower surface of the frame, and the amount of projection of the board from the upper surface and the amount of projection of the board from the lower surface being equal.

Description

Technical Field

[0001] This invention relates to sockets for semiconductor packaging. Background Technology

[0002] In semiconductor packaging sockets for mounting semiconductor elements such as light-emitting elements, a known configuration involves forming a through-hole in a rectangular base and sealing the lead terminals with glass within the through-hole. The base has a component mounting surface for mounting the semiconductor element. After mounting the semiconductor element on the component mounting surface of the base and electrically connecting it to the lead terminals, the semiconductor packaging socket is then welded to the periphery of the base to form a semiconductor package (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-235212 Summary of the Invention

[0006] The problem to be solved by the present invention

[0007] In semiconductor packaging sockets like those described above, the flatness of the base is important in order to ensure a hermetically tight bond between the base and the cover, thus requiring suppression of base warping.

[0008] The present invention is made in view of the above points, and its object is to provide a semiconductor packaging socket that suppresses warping of the object to which the cover is joined.

[0009] means for solving problems

[0010] The semiconductor package socket includes: a plate; a frame located on the outer periphery of the plate in plan view and joined to the plate; and a lead terminal held in an insulated state from the plate and the frame, wherein the plate protrudes from the upper and lower surfaces of the frame, and the amount of protrusion from the upper surface and the amount of protrusion from the lower surface are equal.

[0011] The effects of the invention

[0012] According to the disclosed technology, it is possible to provide a semiconductor packaging socket that suppresses warping of the object to which the cover is attached. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating a semiconductor packaging socket according to this embodiment (one example).

[0014] Figure 2 This is a diagram (second example) illustrating a semiconductor packaging socket according to this embodiment.

[0015] Explanation of reference numerals in the attached figures:

[0016] 1. Semiconductor packaging socket

[0017] 10 plate body

[0018] 10a, 20a upper surface

[0019] 10b, 20b lower surface

[0020] 20 Frames

[0021] 20x and 30x through holes

[0022] 30 Lead holding component

[0023] 31 Large diameter part

[0024] 32 Small diameter section

[0025] 40 lead terminals

[0026] 50 Sealing section Detailed Implementation

[0027] The following description, with reference to the accompanying drawings, illustrates the methods for carrying out the invention. It should be noted that in the drawings, the same reference numerals are used for the same constituent parts, and sometimes repeated descriptions are omitted.

[0028] Figure 1 This is a diagram illustrating, for example, a semiconductor packaging socket according to this embodiment (one of the embodiments). Figure 1 (a) is a three-dimensional view viewed from the top surface side. Figure 1 (b) is a three-dimensional view viewed from the lower surface side. Figure 2 This is a second illustration of a semiconductor packaging socket according to this embodiment. Figure 2 (a) is a partial sectional perspective view viewed from the top surface side. Figure 2 (b) is a partial sectional view.

[0029] Reference Figure 1 and Figure 2 The semiconductor packaging socket 1 of this embodiment has a plate 10, a frame 20, a lead holding member 30, a plurality of lead terminals 40, and a sealing part 50.

[0030] The plate 10, for example, is rectangular in shape when viewed from above, and has an upper surface 10a and a lower surface 10b. The plate 10 has a length of approximately 40mm to 60mm in the longitudinal direction, a width of approximately 20mm to 40mm in the width direction, and a thickness of approximately 3mm to 4mm.

[0031] On the upper surface 10a of the plate 10, multiple semiconductor components such as semiconductor lasers can be mounted. In other words, the upper surface 10a of the plate 10 is a component mounting surface capable of mounting multiple semiconductor components. The lower surface 10b of the plate 10 can be thermally connected to a heat sink or the like, thereby serving as a heat dissipation surface for dissipating heat from the semiconductor components.

[0032] From the viewpoint of heat dissipation for the mounted semiconductor components, it is preferable that the thermal conductivity of the plate 10 is greater than that of the frame 20. As for the material of the plate 10, ceramic or metal can be used, but to improve heat dissipation, metal is preferred. Examples of preferred metals include copper and copper alloys.

[0033] It should be noted that, in this application, "top view" refers to viewing the object from the normal direction of the upper surface 10a of the plate 10, and "planar shape" refers to the shape of the object viewed from the normal direction of the upper surface 10a of the plate 10.

[0034] The frame 20, viewed from above, is located on the outer periphery of the plate 10 and is joined to the plate 10. The frame 20, for example, is frame-shaped when viewed from above. The outer edge of the frame 20 has a length of approximately 50mm to 70mm, a width of approximately 30mm to 50mm, and a thickness of approximately 1mm to 2mm. The inner edge of the frame 20 is determined according to the size of the plate 10 and is the same as the outer edge of the plate 10. The frame 20 can be made of metals such as iron or stainless steel. For example, the inner surface of the frame 20 is integrally joined to the side surface of the plate 10. For the joining of the inner surface of the frame 20 to the side surface of the plate 10, a metal bonding material can be used, for example. Examples of metal bonding materials include silver solder.

[0035] The frame 20 has a plurality of through holes 20x extending from the upper surface 20a to the lower surface 20b through the frame 20. The planar shape of the through holes 20x is, for example, circular, with a diameter of, for example, about 1.5 mm to 3.0 mm. Near each through hole 20x on the lower surface 20b of the frame 20, a lead wire holding member 30 is attached. The material of the lead wire holding member 30 can be a metal such as iron or stainless steel. Preferably, the frame 20 and the lead wire holding member 30 are made of the same material. This is to reduce warping caused by thermal expansion differences during brazing.

[0036] The lead holding member 30 is, for example, a cylindrical large-diameter portion 31 and a cylindrical small-diameter portion 32 with a smaller diameter than the large-diameter portion 31, formed concentrically. The small-diameter portion 32 is inserted into the through hole 20x and engages with the frame 20. Specifically, the side surface of the small-diameter portion 32 engages with the inner side surface of the through hole 20x, and the upper surface of the large-diameter portion 31 engages with the lower surface 20b of the frame 20. For the engagement between the frame 20 and the lead holding member 30, a metal bonding material can be used, for example. Examples of metal bonding materials include silver solder.

[0037] The lead holding member 30 has a through hole 30x that extends through the large-diameter portion 31 and the small-diameter portion 32 in the thickness direction. The lead holding member 30 is fixed to the lower surface 20b side of the frame 20 such that the through hole 30x communicates with the through hole 20x. A lead terminal 40 is inserted into the through hole 30x. The lead terminal 40 is kept insulated from the plate 10, the frame 20, and the lead holding member 30. Specifically, the lead terminal 40 is held in the through hole 30x of the lead holding member 30 without being grounded to the through hole 20x or the inner surface of the through hole 30x. The lead terminal 40 is a component for electrically connecting a semiconductor element mounted on the plate 10 to an external source. Examples of materials for the lead terminal 40 include Kovar alloy and iron-nickel alloy.

[0038] The end of the lead terminal 40 may protrude beyond the through hole 30x. Alternatively, the end of the lead terminal 40 may protrude from the upper surface 20a of the frame 20, but it is preferable to hold the lead terminal 40 by the lead holding member 30 without it protruding from the upper surface 20a of the frame 20, thus allowing for a shorter length. By shortening the length of the lead terminal 40, resonance caused by the frequency of the ultrasonic waves that is easily generated when wire bonding is performed between the semiconductor element mounted on the board 10 and the lead terminal 40 using ultrasonic waves can be suppressed. The thickness of the lead holding member 30 is, for example, about 1 mm to 3 mm. By setting the thickness of the lead holding member 30 to about 1 mm to 3 mm, the lead terminal 40 can be held more securely.

[0039] An insulating sealing portion 50 is provided on the outer periphery of the lead terminal 40 within the through hole 30x. That is, the lead terminal 40 is held within the through hole 30x of the lead holding member 30 by means of the insulating sealing portion 50. Preferably, one through hole 30x is provided for each lead terminal 40. This allows for a reliable seal between the lead terminal 40 and the lead holding member 30 via the sealing portion 50.

[0040] As the material for the sealing portion 50, glass can be used, for example. To provide an hermetic seal for the semiconductor element mounted on the plate 10, the material of the sealing portion 50 is preferably a material whose coefficient of thermal expansion is close to that of the lead holding member 30 and the lead terminal 40. Examples of such materials include borosilicate glass.

[0041] In the semiconductor packaging socket 1, the plate body 10 is formed to be thicker than the frame body 20. The upper surface 10a side of the plate body 10 protrudes from the upper surface 20a of the frame body 20, and the lower surface 10b side of the plate body 10 protrudes from the lower surface 20b of the frame body 20. For example, the upper surface 10a side of the plate body 10 protrudes entirely from the upper surface 20a of the frame body 20, and the lower surface 10b side of the plate body 10 protrudes entirely from the lower surface 20b of the frame body 20.

[0042] The protrusion T1 of the upper surface 10a of the plate 10 from the upper surface 20a of the frame 20 is equal to the protrusion T2 of the lower surface 10b of the plate 10 from the lower surface 20b of the frame 20. The protrusions T1 and T2 are, for example, approximately 0.5 mm to 1.5 mm. It should be noted that, in this application, the equality of protrusions T1 and T2 means that T2 is within the range of T1 ± 100 μm. It should also be noted that, to ensure that the protrusions T1 and T2 are equal, a specialized fixture with high dimensional accuracy can be used for the joining of the plate 10 and the frame 20.

[0043] After a semiconductor package socket 1 mounts a semiconductor component on the upper surface 10a (component mounting surface) of the plate 10 and electrically connects it to the lead terminal 40, a cover is bonded to the upper surface 20a of the frame 20 by soldering or the like, thus forming a semiconductor package. At this point, warping of the plate 10 and the frame 20 becomes a problem. If the warping of the plate 10 and the frame 20 is large, it becomes difficult to bond the cover to the upper surface 20a of the frame 20 by soldering.

[0044] For research purposes, the inventors fabricated a comparative semiconductor packaging socket A, in which the frame is replaced with a rectangular second plate larger than the main plate, and the rectangular plate is joined on top of the second plate, exposing the outer periphery of the second plate around the main plate. The main plate is made of copper, the second plate is made of iron, and the lead terminals are sealed with glass in through holes located on the outer periphery of the second plate. In the semiconductor packaging socket A, the warpage of both the main plate and the second plate is approximately 200 μm. Under these conditions, it is difficult to ensure a hermetically tight connection between the second plate and the cover.

[0045] Next, the inventors, similar to those of the semiconductor packaging socket 1, created a semiconductor packaging socket B with a structure where the amount of protrusion from the upper and lower surfaces of the frame is equal to the amount of protrusion from the upper surface of the frame. However, in the semiconductor packaging socket B, no lead holding component is used, and the lead terminals are sealed with glass in the through-holes provided in the frame. In the semiconductor packaging socket B, the materials of the plate and frame, as well as the thickness of the frame, are set to be the same as those of the semiconductor packaging socket A, and the thickness of the plate is set to a protrusion of 1 mm from the upper and lower surfaces of the frame. In the semiconductor packaging socket B, the warpage of the plate and frame is approximately 100 μm. In this state, the frame and cover can be joined together while maintaining an airtight seal.

[0046] Next, the inventors manufactured a semiconductor packaging socket 1. The semiconductor packaging socket 1 was manufactured under the same conditions as the semiconductor packaging socket B, except that the lead terminals 40 were sealed with glass using an iron lead holding member 30. In the semiconductor packaging socket 1, the warpage of the plate 10 and the frame 20 is less than 50 μm. In this state, the frame and the cover can be joined together while maintaining hermeticity, further improving hermeticity.

[0047] It should be noted that the evaluation of warpage is conducted using a non-contact 3D measuring machine for convexity and concaveness measurement. Specifically, the difference between the lowest and highest points within the plate is measured, and this difference is taken as the magnitude of the plate's warpage. Similarly, the difference between the lowest and highest points within the frame is measured, and this difference is taken as the magnitude of the frame's warpage.

[0048] Generally, in semiconductor packaging sockets, the plate is prioritized for heat dissipation, while the frame is prioritized for hermeticity by utilizing the difference in thermal expansion coefficients between the plate and the sealing portion used to seal the lead terminals. Therefore, different materials are used for the plate and the frame. Consequently, due to the difference in thermal expansion coefficients between the plate and the frame, stress generated, for example, by soldering at temperatures near 800°C, can occur, leading to warping.

[0049] Similar to the semiconductor packaging socket 1, by constructing the plate 10 to protrude from both the upper surface 10a and the lower surface 10b of the frame 20, and setting the protrusion amount T1 from the upper surface 20a and the protrusion amount T2 from the lower surface 20b to be the same, the vertical balance of the frame 20 is improved. Therefore, it is believed that the stress caused by the difference in thermal expansion rates between the plate 10 and the frame 20 is mitigated, warping is suppressed, and the connection between the frame 20 and the cover becomes possible.

[0050] Furthermore, in the semiconductor package socket 1, a lead terminal 40 is inserted into a lead holding member 30. For example, it is also possible to configure the lead holding member as a plate with multiple through holes, into which the lead terminal 40 is inserted. However, in this case, the area of ​​the plate-shaped lead holding member when soldered to the frame 20 increases, which has an adverse effect on the warping of the frame 20. As in the semiconductor package socket 1, by inserting a lead terminal 40 into a lead holding member 30, the area of ​​the lead holding member 30 when soldered to the frame 20 is reduced, thereby reducing the adverse effect on the warping of the frame 20.

[0051] The preferred embodiments have been described in detail above, but are not limited to the above embodiments. Various modifications and substitutions can be made to the above embodiments without departing from the scope of the claims.

Claims

1. A semiconductor packaging socket, comprising: plate body; A frame, which, when viewed from above, is located on the outer periphery of the aforementioned plate and is joined to the aforementioned plate; and The lead terminals are held in a state of insulation from the aforementioned plate and frame. The inner side of the frame is integrally joined to the side of the plate. The plate protrudes from the upper and lower surfaces of the frame, and the amount of protrusion from the upper surface and the amount of protrusion from the lower surface are equal to reduce the warping of the plate and the frame.

2. The semiconductor packaging socket according to claim 1, wherein, The aforementioned plate is rectangular when viewed from above, and the aforementioned frame is frame-shaped when viewed from above.

3. The semiconductor packaging socket according to claim 1 or 2, wherein, The upper surface of the plate protrudes entirely from the upper surface of the frame, and the lower surface of the plate protrudes entirely from the lower surface of the frame.

4. The semiconductor packaging socket according to claim 1 or 2, wherein, It has a first through hole that penetrates the aforementioned frame. It has a lead holding component, which has a second through hole. The aforementioned lead wire holding component is fixed to the lower surface of the frame by means of the connection between the second through hole and the first through hole. The aforementioned lead terminal is held in the second through hole in such a way that it does not contact the inner surface of the first through hole and the second through hole.

5. The semiconductor packaging socket according to claim 4, wherein, The ends of the aforementioned lead terminals are held by the aforementioned lead holding member in a manner that does not protrude from the upper surface of the aforementioned frame.

6. The semiconductor packaging socket according to claim 4, wherein, The aforementioned lead terminal is held within the aforementioned second through hole by means of an insulating seal.

7. The semiconductor packaging socket according to claim 4, wherein, The aforementioned frame and the aforementioned lead wire holding component are made of the same material.

8. The semiconductor packaging socket according to claim 1 or 2, wherein, Both the plate and the frame are made of metal, and the thermal conductivity of the plate is greater than that of the frame.

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