Semiconductor package structure

Abstract

A leadframe is provided that includes a die foot and a plurality of leads that surround the die foot. Each of the leads includes a finger portion proximate the die foot and a lead portion distal from the die foot. The finger portion includes a body and at least one support structure. Respective support structures on adjacent leads are isolated from one another, and the distance between the support structures and the die foot is less than the distance between the lead portions and the die foot. A semiconductor package structure that includes the leadframe described herein and a semiconductor package assembly that includes the semiconductor package structure described herein are also provided.

Description

Technical Field

[0001] This disclosure relates to a semiconductor package structure including a lead frame. Background Technology

[0002] The leadframe includes a die mount and multiple leads extending toward the die mount. A semiconductor die mounted on the die mount is electrically connected to each of the leads via wiring. As the I / O density on semiconductor dies continues to increase, the wiring connecting each I / O to each lead forms a denser arrangement, which tends to cause them to cross or short-circuit.

[0003] The longer the wiring, the more severe the wiring crossing and / or short circuits. To shorten the wiring length, each lead in the leadframe is modified to be longer or closer to the die mount. However, when the length of the finger portion of an individual lead exceeds 2 mm, the terminal ends of the leads close to the die mount droop, causing these terminal ends to be exposed from the molding material after the leadframe encapsulation process. Furthermore, the wiring connecting the semiconductor die's I / O to these terminal ends is dragged and deformed due to the drooping, resulting in signal line failures. Summary of the Invention

[0004] In some embodiments, this disclosure provides a lead frame comprising a die holder and a plurality of leads surrounding the die holder. Each of the leads includes a finger portion adjacent to the die holder and a lead portion distant from the die holder. The finger portion includes a body and at least one support structure. Corresponding support structures on adjacent leads are isolated from each other, and the distance between the support structure and the die holder is less than the distance between the lead portion and the die holder.

[0005] In some embodiments, this disclosure provides a semiconductor package structure including a die holder and a plurality of leads surrounding the die holder. Each of the leads includes a terminal end proximate to the die holder and a lead end distal to the die holder. Each of the leads includes a body and at least one support structure. The distance between the support structure and the terminal end is less than the distance between the support structure and the lead end.

[0006] In some embodiments, this disclosure provides a semiconductor package assembly including a die holder, a plurality of leads surrounding the die holder, and a substrate beneath the die holder and the plurality of leads. Each of the leads includes a finger portion proximate to the die holder and a lead portion distal to the die holder. The finger portion includes a body and at least one support structure. The support structure is dummy relative to the substrate. Corresponding support structures on adjacent leads are isolated from each other, and the distance between the support structure and the die holder is less than the distance between the lead portion and the die holder. Attached Figure Description

[0007] Some aspects of embodiments of this disclosure will be readily understood from the following description when read in conjunction with the accompanying drawings. It should be noted that the various structures may not be drawn to scale, and the dimensions of the various structures may be arbitrarily increased or decreased for clarity of explanation.

[0008] Figure 1 A perspective view of the lead frame as seen from the top surface, according to some embodiments of the present disclosure.

[0009] Figure 2 Drawing from Figure 1 A perspective view of the bottom surface of the lead frame.

[0010] Figure 3 A cross-sectional view of a lead frame according to some embodiments of the present disclosure is shown.

[0011] Figure 4 A cross-sectional view of a semiconductor package structure according to some embodiments of the present disclosure is shown.

[0012] Figure 5 A cross-sectional view of a semiconductor package stripe according to some embodiments of the present disclosure is illustrated.

[0013] Figure 6 A cross-sectional view of a semiconductor package assembly according to some embodiments of the present disclosure is illustrated.

[0014] Figure 7A A bottom view of a lead frame according to some embodiments of the present disclosure is shown, the lead frame showing the support structure for the lead portion and the finger portion.

[0015] Figure 7B Drawing from Figure 7A A cross-sectional view divided by line AA.

[0016] Figure 7C Draw Figure 7A A magnified view of region B.

[0017] Figure 7DA bottom view of a semiconductor package structure according to some embodiments of the present disclosure is shown, the semiconductor package structure comprising Figure 7A The lead frame.

[0018] Figures 8A to 8F Cross-sectional views of semiconductor package structures according to some embodiments of the present disclosure are shown during various manufacturing operation steps. Detailed Implementation

[0019] Common reference numerals are used throughout the drawings and embodiments to indicate the same or similar components. Embodiments of this disclosure will be readily understood from the following description in conjunction with the accompanying drawings.

[0020] The following disclosure provides numerous different embodiments or instances for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to illustrate certain aspects of this disclosure. Of course, these examples are merely illustrative and not intended to be limiting. For instance, in the following embodiments, the formation of a first feature over or on a second feature may include embodiments where the first and second features are formed or disposed in direct contact, and may also include embodiments where additional features may be formed or disposed between the first and second features such that the first and second features do not need to be in direct contact. Furthermore, reference numerals and / or letters may be repeated in various instances of this disclosure. This repetition is for simplicity and clarity and does not in itself define a relationship between the various embodiments and / or configurations discussed.

[0021] As discussed earlier in the background section, another method to shorten the length of the lead's finger portion is to increase the length ratio of the lead portion to the finger portion. Compared to the finger portion of a lead where the metal is partially etched along its thickness, the lead portion contains a metal section with full thickness. Signal transmission through the higher length-to-width ratio of the lead portion may be altered, therefore this is not a universal solution for various semiconductor die packages. Another method to prevent sag of the lead's finger portion is to replace the original material with a higher-strength material. However, the degree of sag reduction is limited.

[0022] This disclosure provides a leadframe having a die holder and a plurality of leads surrounding the die holder. Each of the leads includes a support structure at a finger portion to prevent sagging and to prevent the ends of the leads near the die holder from being exposed from the encapsulation. Similar to the lead portions, the support structure may be a metal segment having full thickness and spaced apart from the side surfaces of the finger portions facing the die holder. This invention provides a semiconductor package structure encapsulating the leadframe discussed herein. This invention also provides a semiconductor package assembly comprising the semiconductor package structure discussed herein and a substrate, such as a PCB.

[0023] See Figure 1 , Figure 1 The diagram illustrates a perspective view of a lead frame 10 as seen from its top surface, according to some embodiments of the present disclosure. The lead frame 10 includes a die holder 101 and a plurality of leads 103 surrounding the die holder 101. Each of the plurality of leads includes a lead portion 103A remote from the die holder 101, a body 103FB, and a support structure 103FS connected to the body 103FB. The body 103FB has a side surface 1031 facing and spaced apart from the die holder 101. The support structure 103FS has a side surface 1032 facing and spaced apart from the die holder 101. Figure 1 The perspective view suggests that the corresponding support structures 103FS on any adjacent lead 103 are isolated from each other, that is, each of the support structures 103FS is integrally integrated with the body 103FB and the lead portion 103A, without being physically coupled to the support structures 103FS on the directly adjacent lead 103.

[0024] Figure 2 Drawing from Figure 1 A perspective view of the bottom surface of the lead frame 10. It has a similar design to... Figure 1 In this context, elements with the same numerical marker refer to the same component and can refer to the same component. From Figure 2 As can be seen from the bottom perspective view, in addition to being isolated from each other, the corresponding support structures 103FS on any of the adjacent leads 103 are also staggered. For example, the support structure 103FS on the first lead does not laterally overlap with the support structure 103FS on the second lead directly adjacent to the first lead. The support structure 103FS on the first lead may be closer to or further away from the die holder 101 than the support structure 103FS on the second lead directly adjacent to the first lead.

[0025] See Figure 3 , Figure 3 This is a cross-sectional view of a lead frame 30 according to some embodiments of the present disclosure. Figure 3 Available from Figure 1 The lines are divided into PP segments, thus displaying the unit of the leadframe panel or leadframe stripes. The leadframe 30 includes a die holder 301 and a plurality of leads 303 surrounding the die holder 301. Figure 3As shown, the die holder 301 is surrounded by a left lead 303 and a right lead 303. Each of the leads 303 includes a finger portion 303F closer to or near the die holder 301, and a lead portion 303A further away from or away from the die holder 301. In some embodiments, the lead 303 includes a lead end or side surface 3035" facing away from the lead portion 303A of the die holder 301, and a terminal end or side surface 3031 facing the finger portion 303F of the die holder 301. The lead end and the terminal end are opposite each other.

[0026] A support structure 303FS is positioned at a specific location on the body 303FB of the finger portion 303F, wherein the distance DS between the support structure 303FS and the die holder 301 (e.g., the proximal edge of the die holder) is less than the distance DL between the lead portion 303A and the die holder 301 (e.g., the proximal edge of the die holder). Alternatively, the distance S3 between the support structure 303FS and the terminal end (i.e., the side surface 3031 of the body 303FB) is less than the distance S2 between the support structure 303FS and the lead end (i.e., the side surface 3035 of the lead portion 303A). Positioning the support structure 303FS at the aforementioned location prevents long leads of the lead frame (e.g., leads with a finger length WN greater than 2.0 mm) from drooping at the terminal end, while simultaneously shortening the wiring length required for electrically connecting the semiconductor die and the corresponding lead.

[0027] The finger portion 303F further includes a body 303FB, which is connected at one end to the lead portion 303A and faces the die holder 301 at the opposite end. A side surface 3031 of the body 303FB facing the die holder 301 is spaced apart from a side surface 3011 of the die holder 301. The body 303FB of the finger portion 303F includes an upper surface 3033, a lower surface 3034, and a side surface 3031 connecting the upper surface 3033 and the lower surface 3034, thereby forming a generally vertical boundary. The finger portion 303F further includes a support structure 303FS located at a position retracted from the end of the finger portion 303F facing the die holder 301. A support structure 303FS may protrude from the lower surface 3034 of the body 303FB and have a side surface 3032 that is removable from or spaced apart from the side surface 3031 of the body 303FB. In some embodiments, depending on various design requirements, more than one support structure 303FS may be disposed at the finger portion 303F. For example, if the finger length WN is long enough to accommodate more than one support structure 303FS, then two or more support structures 303FS may be designed to support the finger portion 303F, wherein there is a predetermined interval between each of the support structures 303FS. Criteria for the predetermined interval can be found in the present disclosure. Figure 7C .

[0028] Similar to side surface 3031, side surface 3032 of support structure 303FS faces and is spaced apart from side surface 3012 of die holder 301. Side surface 3031 of body 303FB and side surface 3032 of support structure 303FS are connected by a portion of lower surface 3034 of body 303FB. Support structure 303FS further includes a lower surface 3036 that is substantially flush with lower surface 3035 of lead portion 303A. In some embodiments, side surface 3032 is recessed from side surface 3031 by a predetermined distance S3 to prevent under-etching of portions of body 303FB adjacent to support structure 303FS during half-etch and full-etch operation steps, as will be described in this disclosure. Figure 8C As discussed in [the document]. In some embodiments, when the finger length WN is greater than 2.0 mm, the predetermined distance S3 may be greater than about 400 μm. In some embodiments, the predetermined distance S3 may be greater than about 400 μm, regardless of the finger length WN.

[0029] In some embodiments, the side surface 3012 retracts from the side surface 3011 of the die holder 301 to increase the size of the die holder 301 and the encapsulation material encapsulating the die holder 301. Figure 3(Not shown in the text) Adhesion capability. However, the die holder 301 described herein may include a vertical side surface connecting the upper and lower surfaces without any retracted portion. A bonding section 303FC is defined between side surfaces 3031 and 3032, the bonding section being configured to electrically connect the semiconductor die on the die holder 301 to each of a plurality of leads via a wiring housing.

[0030] The lateral protrusion of the side surface 3031 of the main body 303FB overlaps with a portion of the side surface 3011 and the lead portion 303A. In contrast, the lateral protrusion of the side surface 3031 does not overlap with the side surface 3032 of the support structure 303FS.

[0031] In some embodiments, since the lead portion 303A is configured to exit from the encapsulation ( Figure 3 (Not shown) The lead portion 303A is exposed and bonded to conductive pads or traces on the underlying substrate of, for example, a printed circuit board (PCB). Therefore, the width WA of the lead portion 303A is generally wider than the width WS of the support structure 303FS. The conductive pads or traces of the PCB can be exposed from openings in the solder mask, thereby allowing electrical connections to be formed with the lead portion 303A. In contrast, the conductive pads or traces of the PCB can be arranged away from the vertical protrusion area of ​​the support structure 303FS, and the solder mask can cover the vertical protrusion area of ​​the support structure 303FS.

[0032] Figure 4 This is a cross-sectional view of a semiconductor package structure 40 according to some embodiments of the present disclosure. The semiconductor package structure 40 is similar to... Figure 3 The lead frame 30, in addition to forming an encapsulation 403 to encapsulate the lead frame 30, has an encapsulation 403 covering each of the die holder 301 and the leads 303 from at least its upper and side surfaces. For example, the upper surface 3033 of the body 303FB of the finger portion 303F, the side surface 3031 of the body 303FB, and the side surface 3032 of the support structure 303FS are in contact with the encapsulation 403. For example, the side surface 3032' of the support structure 303FS, the lower surface 3034 of the body 303FB, and the side surface 3035' of the lead portion 303A are in contact with the encapsulation 403, or in other words, the encapsulation 403 is enclosed by the space defined by the body 303FB, the support structure 303FS, and the lead portion 303A.

[0033] The semiconductor package structure 40 further includes a semiconductor die 401 disposed on a die holder 301. A bonding segment 303FC on the body 303FB is defined between side surfaces 3031 and 3032, the bonding segment being configured to electrically connect the semiconductor die 401 to each of a plurality of leads via a housing wiring 405. Figure 4As shown, the lower surface 3036 of the support structure 303FS and the lower surface 3035 of the lead portion 303A are exposed from the encapsulation 403. The lead portion 303A is configured to be exposed from the encapsulation 403 and to bond with conductive pads or traces of an underlying carrier, such as a printed circuit board (PCB). The conductive pads or traces of the PCB may be exposed from openings in the solder mask layer, thereby allowing electrical connections to be formed with the lead portion 303A. In some embodiments, the lower surface 3036 of the support structure 303FS and the lower surface 3035 of the lead portion 303A are substantially coplanar with the lower surface of the encapsulation 403. The support structure 303FS can provide additional contact areas with the encapsulation 403 to increase the adhesion between the encapsulation (e.g., molding material) and the lead 303. In other words, the support structure 303FS acts as a mold lock in this structure.

[0034] Figure 5 This is a cross-sectional view of a semiconductor package stripe 50 according to some embodiments of the present disclosure. Figure 5 The semiconductor package stripe 50 illustrated includes two semiconductor package structures 50A and 50B, which are separated along a single tangent S between adjacent leadframe packages. Additionally, a tin layer 501 contacts a portion of the leadframe exposed from the encapsulation 403. For example, the tin layer 501 contacts the lower surface of the die holder 301, the lower surface of the support structure 303FS, and the lower surface of the lead portion 303A. In some embodiments, the tin layer 501 is formed by an electroplating operation step after encapsulating the leadframe.

[0035] Figure 6 This is a cross-sectional view of a semiconductor package assembly 60 according to some embodiments of the present disclosure. The semiconductor package assembly 60 is similar to... Figure 5 In the semiconductor package structure 50A or 50B, except for an additional substrate 601 beneath the die holder 301 and multiple leads 303, the support structure 303FS is a dummy structure relative to the substrate 601 (e.g., PCB), except that the conductive terminal 603 is positioned to connect the lead portion 303A to the conductive pattern 605 (e.g., conductive pad or trace) of the substrate 601.

[0036] In some embodiments, a gap G (e.g., an air gap) exists between the support structure 303FS and the upper surface of the substrate 601 to accommodate a conductive terminal 603, such as solder. The conductive terminal 603 and the lower surface 4031 of the encapsulation 403 are exposed to the gap G. Figure 6As illustrated, the conductive pattern 605 of the PCB can be exposed from the opening in the solder mask layer, thereby allowing electrical connection to the lead portion 303A through the conductive terminals 603. In contrast, the conductive pads or traces of the PCB can be arranged away from the vertical protrusion area of ​​the support structure 303FS, and the solder mask layer can cover the vertical protrusion area of ​​the support structure 303FS. In addition, due to the strip or panel singulation operation step, the lead ends or side surfaces 3035" of the lead portion 303A are exposed from the side surface 4032 of the encapsulation 403. In some embodiments, the support structure 303FS and the tin layer 501 exposed to the gap G can serve as additional heat dissipation channels to effectively dissipate the heat generated by the semiconductor die 401.

[0037] Figure 7A The following is a bottom view of a lead frame according to some embodiments of the present disclosure, showing a support structure for the lead portion 303A and the finger portion 303F. Figure 7B From Figure 7A A cross-sectional view divided by line AA. See also Figure 7A and Figure 7B In some embodiments, from a planar view, the body 303FB of the finger portion 303F of each of the leads has a lateral width WF, for example, about 90 μm. From a planar view, the support structure 303FS protruding from the lower surface of the body 303FB has a lateral width WS', for example, equal to or smaller than the lateral width WF of the body 303FB. The lateral width WF of the support structure 303FS may be substantially the same as the lateral width WS' of the support structure 303FS. In some embodiments, depending on various design requirements, the support structure 303FS may include a square lower surface, a circular lower surface, or a quadrilateral lower surface.

[0038] Each of the support structures 303FS includes a lower surface 3036 that is substantially flush with the lower surface 3035 of the lead portion 303A. The corresponding support structures 303F in adjacent leads are isolated from each other; that is, the corresponding support structures 303F are discrete components without physical or electrical connections. The arrangement of the corresponding support structures 303F in each lead is designed to be staggered. For example, the support structure 303FS of the first lead 701 is spaced apart from the terminal end 3031 by a first distance, and the support structure 303FS of the second lead 702 adjacent to the first lead 701 is spaced apart from the terminal end 3031 by a second distance. The first distance differs from the second distance. When the corresponding support structures 303FS on adjacent leads follow the above arrangement, all corresponding support structures 303FS can be arranged in an interleaved manner.

[0039] See Figure 7C , Figure 7C for Figure 7A An enlarged view of region B. In some embodiments, the support structure 303FS on the first lead 701 follows design rules to be spaced apart from the support structure 303FS on the second lead 702 or adjacent leads by a distance S1, for example, at least 200 μm. Distance S1 is measured along the finger portion 303F of each of the leads 303 along the main direction PD. In some embodiments, the support structure 303FS on either the first lead 701 or the second lead 702 follows design rules to be spaced apart from the lead portion 303A by a distance S2, for example, at least 200 μm. Distance S2 is measured along the finger portion 303F of each of the leads 303 along the main direction PD. Distances S1 and S2 are designed to prevent insufficient etching of portions of the body 303FB adjacent to the support structure 303FS, and to prevent solder bridging between adjacent support structures 303FS and / or lead portions 303A after the encapsulation is formed to cover the leads 303 and the die holder 301.

[0040] In some embodiments, the support structure 303FS is retracted from the terminal end 3031 by a predetermined distance S3 to prevent insufficient etching of the portion of the body 303FB adjacent to the support structure 303FS during half-etching and full-etching operation steps, as will be described in this disclosure. Figure 8C As discussed in [the document]. In some embodiments, when the finger length WN is greater than 2.0 mm, the predetermined distance S3 may be greater than about 400 μm. In some embodiments, the predetermined distance S3 may be greater than about 400 μm, regardless of the finger length WN.

[0041] Figure 7D This is a bottom view of a semiconductor package structure according to some embodiments of the present disclosure, the semiconductor package structure comprising Figure 7A The lead frame. Viewed from the bottom plane. Figure 7D The semiconductor package structure shown depicts the lower surface 4031 of the encapsulation 403. The lower surface 3036 of the support structure 303FS is exposed from the lower surface 4031 of the encapsulation 403. Similarly, the lower surface 3035 of the lead portion 303A is exposed from the lower surface 4031 of the encapsulation 403. The exposed lower surface 3036 of the support structure 303FS serves to position the lead frame at specific locations after the encapsulation process. For example, the terminal end of each lead can be located by inspecting the exposed lower surface 3036 of the support structure 303FS. The body 303FB of the corresponding finger portion 303F is embedded beneath the encapsulation 403 and is therefore depicted by dashed lines. A conductive layer, such as a tin layer, is deposited on the exposed lower surfaces 3035 and 3036 to prepare for subsequent shaping processes.

[0042] Figures 8A to 8FThis is a cross-sectional view of a semiconductor package structure according to some embodiments of the present disclosure during various manufacturing operation steps. Figure 8A In this embodiment, a metal plate 801 is provided. In some embodiments, the metal plate 801 may be a copper plate. Figure 8B and Figure 8C In this process, a metal plate 801 is etched to form a lead frame. The metal plate 801 includes an upper surface 801A and a lower surface 801B. A masking layer 80a having a first pattern is formed over the upper surface 801A of the metal plate 801. The first pattern may include a plurality of openings 82a that expose the upper surface 801A of the metal plate 801 at predetermined locations. Similarly, a masking layer 80b having a second pattern is formed over the lower surface 801B of the metal plate 801. The second pattern may include a plurality of openings 82b that expose the lower surface 801B of the metal plate 801 at predetermined locations. Etching operations are performed on surfaces 801A and 801B of the metal plate 801. For example, full etching is performed at the location where openings 82a and 82b overlap, half etching is performed at the location where only one of openings 82a and 82b exists, and no etching is performed on the surfaces 801A and 801B where they are covered by masking layers 80a and 80b.

[0043] exist Figure 8C In this process, after the etching operation is completed, a lead portion 303A, a body 303FB, and a support structure 303FS are formed. Full etching is performed between the die holder 301 and the lead 303, so that, from a cross-sectional view, the lead 303 is disconnected from the die holder 301. The thickness T2 of the support structure 303FS is substantially the same as the thickness T3 of the lead portion 303A. The thickness T1 of the body 303FB is thinner than either thickness T2 or thickness T3. In some embodiments, the lower surface 3035 of the lead portion 303A is substantially flush with the lower surface 3036 of the support structure 303FS.

[0044] exist Figure 8D In this configuration, a semiconductor die 401 is placed on a die holder 301, and a wiring 405 is formed to connect the I / O on the semiconductor die 401 to the corresponding body 303FB of the lead. In some embodiments, the wiring 405 is connected to a bonding section 303FC of the body 303FB. In some embodiments, the bonding kit may be omitted to not support the terminal ends of the lead, because the support structure 303FS can provide mechanical support when a wedge-shaped bond is imposed on the bonding section 303FC of the body 303FB.

[0045] exist Figure 8E In the middle, it is sealed by encapsulant 403. Figure 8DThe intermediate semiconductor package structure, wherein the encapsulant is, for example, a molding compound or a molding compound with thermally conductive filler. The lower surface 3036 of the support structure 303FS and the lower surface 3035 of the lead portion 303A are exposed from the encapsulant 403. Figure 8F In this process, a conductive layer 501, for example a tin layer, will be deposited on the lower surfaces 3035 and 3036 to prepare for subsequent shaping operations. The formation of the conductive layer 501 may include an electroplating operation.

[0046] Unless otherwise specified, spatial descriptions such as “above,” “below,” “upward,” “left,” “right,” “downward,” “top,” “bottom,” “vertical,” “horizontal,” “side,” “higher,” “lower,” “upper,” “above,” “below,” etc., are indicated relative to the orientation shown in the figures. It should be understood that the spatial descriptions used herein are for illustrative purposes only, and actual embodiments of the structures described herein can be arranged in space in any orientation or manner, provided that the advantages of the embodiments of this disclosure are not deviated from by such arrangements.

[0047] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate small variations. When used in conjunction with an event or situation, the terms may refer to instances where the event or situation exactly occurred, or instances where the event or situation is very close to occurring. For example, when used in conjunction with a numerical value, the terms may refer to a range of variation less than or equal to ±10% of the stated value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, if the first value is within ±10% of the second value, such as ±5%, ±4%, ±3%, ±2%, ±1%, ±0.5%, ±0.1%, or ±0.05%, then the first value can be considered "substantially" the same as or equal to the second value.

[0048] If the displacement between two surfaces is no greater than 5 μm, 2 μm, 1 μm, or 0.5 μm, then the two surfaces can be considered coplanar or substantially coplanar. If the displacement between the highest and lowest points of a surface is no greater than 5 μm, 2 μm, 1 μm, or 0.5 μm, then the surface can be considered substantially flat.

[0049] As used herein, unless the context clearly indicates otherwise, the singular terms “a / an” and “the” may include multiple indicators.

[0050] As used herein, the terms "conductive / electrically conductive" and "electrical conductivity" refer to the ability to conduct electric current. Conductive materials are generally those that exhibit minimal or no resistance to the flow of electric current. One measure of conductivity is Siemens per meter (S / m). Typically, conductive materials have a conductivity greater than approximately 10. 4 S / m, for example, at least 10 5 S / m or at least 10 6 The conductivity of a material is measured in S / m. The conductivity of a material can sometimes vary with temperature. Unless otherwise specified, the conductivity of a material is measured at room temperature.

[0051] In addition, quantities, ratios, and other values ​​are sometimes presented in range format in this document. It should be understood that such range format is used for convenience and simplicity, and should be flexibly interpreted to include not only the values ​​explicitly specified as the limits of the range, but also all individual values ​​or subranges covered within the range, as if each value and subrange were explicitly specified.

[0052] Although this disclosure has been described and illustrated with reference to specific embodiments thereof, such descriptions and illustrations are not limiting. Those skilled in the art will understand that various changes and alternatives may be made without departing from the true spirit and scope of this disclosure as defined by the appended claims. Illustrations may not be drawn to scale. Due to manufacturing processes and tolerances, artistic representations in this disclosure may differ from actual equipment. Other embodiments of this disclosure may exist that are not specifically described. The description and drawings should be considered illustrative rather than limiting. Modifications may be made to suit particular circumstances, materials, compositions, methods, or processes to the objectives, spirit, and scope of this disclosure. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a particular order, it should be understood that these operations may be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of this disclosure. Therefore, unless specifically indicated herein, the order and grouping of operations are not limitations of this disclosure.

Claims

1. A lead frame, comprising: bare plate base; Multiple leads surround the die holder, each of the leads including a finger portion close to the die holder and a lead portion away from the die holder, the finger portion including a body and at least one support structure; and A substrate is located below the die holders and the plurality of leads. The support structure is dummy relative to the substrate, wherein a gap exists between the bottom of the support structure and the upper surface of the substrate. The corresponding support structures on adjacent leads are isolated from each other, and the distance between the support structure and the die holder is less than the distance between the lead portion and the die holder.

2. The lead frame according to claim 1, wherein the support structure is not electrically connected to the substrate.

3. The lead frame according to claim 1, wherein the lower surface of the lead portion is substantially flush with the lower surface of the support structure, wherein the first distance between the support structure and the first side surface of the body facing the die holder is less than the second distance between the support structure and the third side surface of the lead portion facing away from the die holder.

4. The lead frame according to claim 1, wherein, viewed from a cross-sectional perspective, the width of the lead portion is wider than the width of the support structure, and the thickness of the lead portion is substantially equal to the thickness of the support structure.

5. The lead frame according to claim 1, wherein the body of the finger portion has a first width and the support structure has a second width, wherein, from a planar perspective, the second width is equal to or less than the first width.

6. The lead frame according to claim 1, wherein, from a planar perspective, the support structure of the first lead and the support structure of the second lead adjacent to the first lead are arranged alternately.

7. The lead frame of claim 1, wherein the support structure of the first lead is spaced at least 200 μm apart from the support structure of the second lead adjacent to the first lead along the main direction of the finger portion.

8. The lead frame of claim 1, wherein the support structure of the first lead is spaced at least 200 μm apart from the lead portion of the second lead adjacent to the first lead along the main direction of the finger portion.

9. The lead frame of claim 1, wherein the first side surface of the body facing the die holder and the second side surface of the support structure facing the die holder are spaced at least 400 μm apart along the main direction of the finger portion.

10. A semiconductor package structure comprising: bare plate base; Multiple leads surround the die holder, each of the leads including a terminal end near the die holder and a lead end away from the die holder, each of the leads including a body and at least one support structure; and A substrate is located below the die holders and the plurality of leads. The support structure is dummy relative to the substrate, wherein a gap exists between the bottom of the support structure and the upper surface of the substrate. The distance between the support structure and the end of the terminal is less than the distance between the support structure and the end of the lead wire.

11. The semiconductor package structure of claim 10, further comprising an encapsulation covering the die base and the leads, wherein the terminal ends are in contact with the encapsulation.

12. The semiconductor packaging structure according to claim 10, further comprising: A semiconductor die, which is mounted on the die holder; and A conductive line that connects the semiconductor die to a portion of the lead adjacent to the end of the terminal.

13. The semiconductor package structure of claim 12, further comprising a tin layer in contact with the lower surface of the support structure and exposed to the gap, wherein the tin layer is a heat dissipation channel to dissipate heat generated by the semiconductor die.

14. The semiconductor package structure of claim 10, wherein the corresponding support structures on adjacent leads are isolated from each other and staggered, wherein the support structure comprises a circular lower surface or a quadrilateral lower surface.

15. The semiconductor packaging structure according to claim 14, wherein the quadrilateral lower surface is a square lower surface.

16. A semiconductor package assembly comprising: bare plate base; Multiple leads surround the die holder, each of the leads including a finger portion close to the die holder and a lead portion away from the die holder, the finger portion including a body and at least one support structure; and A substrate is located below the die holders and the plurality of leads. The support structure is dummy relative to the substrate, wherein a gap exists between the bottom of the support structure and the upper surface of the substrate. The corresponding support structures on adjacent leads are isolated from each other, and the distance between the support structure and the die holder is less than the distance between the lead portion and the die holder.

17. The semiconductor package assembly of claim 16, wherein the lead portion is bonded to the substrate via solder.

18. The semiconductor package assembly of claim 16, wherein the solder resist of the substrate is below the protrusion of the support structure.

19. The semiconductor package assembly of claim 16, wherein, viewed from a top view, the length of the lead portion along the principal direction of the finger portion is greater than the length of the support structure, and the width of the lead portion in the principal direction perpendicular to the finger portion is greater than the width of the support structure.

20. The semiconductor package assembly of claim 16, further comprising an encapsulation covering the die base and the leads, wherein the lower surface of the encapsulation is exposed to the gap.

21. The semiconductor package assembly of claim 20, wherein the side surface of the lead portion opposite to the die holder is exposed from the side surface of the encapsulation.

Images