Semiconductor package having partially plated lead flank and method of making the same

Abstract

A semiconductor package includes a leadframe, a wafer, and a molded package. The leadframe includes one or more die pads and a plurality of leads. Each of the plurality of leads includes a base member and a protruding member. The width of the end face of the protruding member of each of the plurality of leads is less than 50% of the width of the corresponding base member to improve solderability. A method for manufacturing a semiconductor package includes the steps of providing a leadframe array, mounting a wafer, forming a molded package, applying a dicing or stamping process, applying a plating process, and applying a monolithic process.

Description

[Technical Field]

[0001] This invention generally relates to a semiconductor package and a method of manufacturing the same, the semiconductor package having a plurality of leads with partially plated sides. More specifically, this invention relates to a semiconductor package manufactured using a lead frame including barrier bars and grooves. [Previous Technology]

[0002] Traditional quad flat leadless and twin flat leadless cables contain lead packages with exposed copper on the lead surface after dicing or stamping processes. The exposed copper oxidizes over time. Oxidized copper end faces degrade solder joint quality.

[0003] The present invention provides a solution by introducing a blocking strip and multiple grooves in the lead frame to form multiple leads with a wettable area of ​​more than 50% in the end region, and to form multiple leads on two opposite side surfaces of each lead. [Summary of the Invention]

[0004] The purpose of this invention is to provide a semiconductor package with partially plated lead sides and a method for manufacturing the same.

[0005] To achieve the above objectives, the present invention provides a semiconductor package comprising: a lead frame including: one or more die pads; and

[0006] A first group of multiple leads extending along a first direction from the one or more die pads, each of the first group of multiple leads comprising: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the first group of multiple leads, the protruding member of the first group of multiple leads comprising: an end face; a wafer attached to one or more die pads of the lead frame; and a molded package of the wafer; wherein the width of the end face of the protruding member of each of the first group of multiple leads is less than 50% of the width of the base member of each of the first group of multiple leads; and wherein the end face of the protruding member of each of the first group of multiple leads is not plated with a wettable metal for soldering.

[0007] Optionally, more than 50% of the first side surface of the base member of each of the first group of multiple leads and more than 50% of the second side surface of the base member of each of the first group of multiple leads are plated with a wettable metal for welding.

[0008] Optionally, each of the first group of multiple leads further includes: a first notch located between a first side surface of the base member of each of the first group of multiple leads and an end face of the protruding member of each of the first group of multiple leads; and a second notch located between a second side surface of the base member of each of the first group of multiple leads and an end face of the protruding member of each of the first group of multiple leads; and wherein the surface of the first notch of each of the first group of multiple leads and the surface of the second notch of each of the first group of multiple leads are plated with a wettable metal for soldering.

[0009] Optionally, the protruding member of each of the first group of multiple leads further includes: a first flat side surface; and a second flat side surface opposite to the first flat side surface; wherein the base member of each of the first group of multiple leads further includes: a first flat end surface that is perpendicular to and directly connected to the first side surface of the base member of each of the first group of multiple leads; and a second flat end surface that is perpendicular to and directly connected to the second side surface of the base member of each of the first group of multiple leads; wherein the first flat side surface of the protruding member of each of the first group of multiple leads, the second flat side surface of the protruding member of each of the first group of multiple leads, the first flat end surface of the base member of each of the first group of multiple leads, and the second flat end surface of the base member of each of the first group of multiple leads are all plated with a wettable metal for soldering.

[0010] Optionally, it further includes a second set of plurality of leads extending away from the one or more die pads along a second direction opposite to the first direction, each of the second set of plurality of leads including: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the second set of plurality of leads, the protruding member of the second set of plurality of leads including: an end face; wherein the width of the end face of the protruding member of each of the second set of plurality of leads is less than 50% of the width of the base member of each of the second set of plurality of leads; wherein more than 50% of the first side surface of the base member of each of the second set of plurality of leads and more than 50% of the second side surface of the base member of each of the second set of plurality of leads are plated with a wettable metal for soldering; and wherein the end face of the protruding member of each of the second set of plurality of leads is not plated with a wettable metal for soldering.

[0011] Optionally, each of the second group of multiple leads further includes: a first notch located between a first side surface of the base member of each of the second group of multiple leads and an end face of the protruding member of each of the second group of multiple leads; and a second notch located between a second side surface of the base member of each of the second group of multiple leads and an end face of the protruding member of each of the second group of multiple leads; and wherein the surface of the first notch of each of the second group of multiple leads and the surface of the second notch of each of the second group of multiple leads are both plated with a wettable metal for soldering.

[0012] Optionally, the protruding member of each of the second group of multiple leads further includes: a first flat side surface; and a second flat side surface opposite to the first flat side surface; wherein the base member of each of the second group of multiple leads further includes: a first flat end surface perpendicular to and directly connected to the first side surface of the base member of each of the second group of multiple leads; a base and a second flat end surface perpendicular to and directly connected to the second side surface of the base member of each of the second group of multiple leads; wherein the first flat side surface of the protruding member of each of the second group of multiple leads, the second flat side surface of the protruding member of each of the second group of multiple leads, the first flat end surface of the base member of each of the second group of multiple leads, and the second flat end surface of the base member of each of the second group of multiple leads are all plated with a wettable metal for soldering.

[0013] Optionally, the lead frame further includes: a third group of multiple leads extending away from the one or more die pads along a third direction perpendicular to the first direction, each of the third group of multiple leads including: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the third group of multiple leads, the protruding member of the third group of multiple leads including: an end face; and a fourth group of multiple leads extending away from the one or more die pads along a fourth direction opposite to the third direction, each of the fourth group of multiple leads including: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the fourth group of multiple leads, the protruding member of the fourth group of multiple leads including: an end face; wherein the width of the end face of the protruding member of each of the third group of multiple leads is less than 50% of the width of the base member of each of the third group of multiple leads; In the third group of multiple leads, at least 50% of the first side surface of the base member of each lead and at least 50% of the second side surface of the base member of each lead in the third group of multiple leads are plated with a wettable metal for welding; wherein the end face of the protruding member of each lead in the third group of multiple leads is not plated with a wettable metal for welding; wherein the width of the end face of the protruding member of each lead in the fourth group of multiple leads is less than 50% of the width of the base member of each lead in the fourth group of multiple leads; wherein at least 50% of the first side surface of the base member of each lead in the fourth group of multiple leads and at least 50% of the second side surface of the base member of each lead in the fourth group of multiple leads are plated with a wettable metal for welding; and wherein the end face of the protruding member of each lead in the fourth group of multiple leads is not plated with a wettable metal for welding.

[0014] The present invention also provides a method for manufacturing a semiconductor package, the method comprising the steps of: providing a leadframe array, the leadframe array comprising: one or more leadframes, each of the one or more leadframes including one or more die pads; a first blocking strip comprising: a first group of multiple blocking strip connection portions; a second blocking strip comprising: a second group of multiple blocking strip connection portions; a first group of multiple grooves located between the first blocking strip and a first side of each leadframe; a second group of multiple grooves located between the second blocking strip and a second side of each leadframe, the second side of each leadframe being opposite to the first side of each pinframe; a first group of multiple leads extending along a first direction away from one or more die pads, each of the first group of multiple leads being connected to the first blocking strip; and a second group of multiple leads extending along a second direction opposite to the first direction away from one or more die pads, each of the second group of multiple leads being connected to the second blocking strip; mounting a wafer on one or more die pads; and forming a molded package of the packaged wafer; The first group of multiple barrier strip connection parts and the second group of multiple barrier strip connection parts are removed by cutting or stamping processes; tin plating is performed on the parts of the lead frame array that are not covered by the molded package; and a monolithic process is applied.

[0015] Optionally, a wire bonding process or a clip bonding process may be applied prior to the step of forming the molded package.

[0016] Optionally, each of the first group of multiple blocking strip connecting portions and the second group of multiple blocking strip connecting portions includes: a first end; a central portion; and a second end opposite to the first end; wherein the cross-sectional area of ​​the first end is smaller than the cross-sectional area of ​​the central portion; and wherein the cross-sectional area of ​​the second end is smaller than the cross-sectional area of ​​the central portion. Optionally, each of the first group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the first group of multiple leads; wherein the width of the protruding member of each of the first group of multiple leads is less than 50% of the width of the base member of each of the first group of multiple leads; wherein each of the second group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the second group of multiple leads; and wherein the width of the protruding member of each of the second group of multiple leads is less than 50% of the width of the base member of each of the second group of multiple leads. Optionally, each of the first group of multiple barrier strip connecting portions includes: a first arc-shaped portion; and a second arc-shaped portion; and wherein each of the second group of multiple barrier strip connecting portions includes: a first arc-shaped portion; and a second arc-shaped portion. Optionally, each lead frame of the one or more lead frames further includes: a first group of multiple rectangular holes located between the first group of multiple barrier strip connecting portions and one or more die pads; wherein the lateral dimension of each of the first group of multiple rectangular holes is smaller than the lateral dimension of the corresponding barrier strip connecting portion in the first group of multiple barrier strip connecting portions.

[0017] Optionally, each of the one or more lead frames further includes: a third blocking strip comprising: a third group of multiple blocking strip connecting portions; a fourth blocking strip comprising: a fourth group of multiple blocking strip connecting portions; a third group of multiple grooves located between the third blocking strip and a third side of each lead frame; a fourth group of multiple grooves located between the fourth blocking strip and a fourth side of each lead frame, the fourth side of each lead frame being opposite to the third side of each lead frame; a third group of multiple leads extending away from one or more die pads along a third direction perpendicular to the first direction, each of the third group of multiple leads being connected to the third blocking strip; and a fourth group of multiple leads extending away from one or more die pads along a fourth direction opposite to the third direction, each of the fourth group of multiple leads being connected to the fourth blocking strip; and wherein the application of the cutting or stamping process further removes the third group of multiple blocking strip connecting portions and the fourth group of multiple blocking strip connecting portions.

[0018] Optionally, each of the third group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the third group of multiple leads; wherein the width of the protruding member of each of the third group of multiple leads is less than 50% of the width of the base member of each of the third group of multiple leads; wherein each of the fourth group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the fourth group of multiple leads; and wherein the width of the protruding member of each of the fourth group of multiple leads is less than 50% of the width of the base member of each of the fourth group of multiple leads.

[0019] Optionally, each of the one or more lead frames further includes: a first group of multiple holes, each hole being located between a pair of grooves in the first group of grooves; and a second group of multiple holes, each hole in the second group of multiple holes being located between a corresponding pair of grooves in the second group of multiple grooves.

[0020] In summary, compared with the prior art, the semiconductor packaging and manufacturing method thereof provided by the present invention have the following beneficial effects:

[0021] The semiconductor package of the present invention includes a lead frame, a wafer, and a molded package. The lead frame includes one or more die pads and a plurality of leads. Each of the plurality of leads includes a base member and a protruding member. The width of the end face of the protruding member of each of the plurality of leads is less than 50% of the width of the corresponding base member in order to improve solderability.

Implementation Method

[0023] The technical solutions, structural features, objectives and effects of the present invention will be described in detail below with reference to Figures 1 to 7 in the embodiments of the present invention.

[0024] It should be noted that the drawings are in a very simplified form and all use non-precise proportions. They are only used to help to explain the implementation of the present invention in a convenient and clear way, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention, provided that it does not affect the effects and objectives that the present invention can produce.

[0025] It should be noted that, in this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the elements expressly listed, but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0026] FIG1 shows a perspective view of a semiconductor package 100 according to an example of the present disclosure. In one example, the semiconductor package 100 is a stamped double-plane lead-free (DFN) package. The semiconductor package 100 includes a lead frame 510 of FIG5A, a wafer 550 of FIG5B, and a molded package 190. The lead frame 510 includes one or more die pads 512 of FIG5A and a first set of multiple leads 120. The first set of multiple leads 120 extends away from the one or more die pads 512 of FIG5A along a first direction Y. Although four leads 122, 124, 126, and 128 are shown in FIG1, the number of leads included in the first set of multiple leads 120 may vary. Each of the first set of multiple leads 120 includes a base member (or base portion) extending outside the molded package and a protruding member (or tip portion) extending to the end of each lead. For example, lead 122 includes a base member 132 and a protruding member 142. In one example, the thickness of the base member 132 is equal to the thickness of the protruding member 142. The protruding member 142 is directly connected to the base member 132. The base member 132 includes a first side 133 and a second side 135. The protruding member 142 includes an end face 143. The portion 139 of the first side 133 of the base member 132 adjacent to the molded package (representing the non-shaded area of ​​copper exposed after the cutting process) is unplated. The end face 143 of the protruding member 142 is located at the central portion of the end of the lead 122 and is unplated. The shaded area 134 of the base member 132 and the shaded area 144 of the protruding member 142 are plated with a solderable wettable metal. The shaded area 134 of the base member 132 is directly connected to the protruding member 142. In one example, the solderable wettable metal covers the shaded area 134 of the base member 132 and the shaded area 144 of the protruding member 142. In one example, the wettable metal used for soldering is tin or Sn.

[0027] The chip 550 of FIG5B is attached to one or more die pads 512 of FIG5A in the lead frame 510 of FIG5A. The molded package 190 surrounds the chip 550 of FIG5B.

[0028] FIG. 2A shows a top view of the lead 122 of FIG. 1 in an example of this disclosure. The width 248 of the end face 143 of the protruding member 142 of the lead 122 is less than 50% of the width 238 of the base member 132 of the lead 122, in order to reduce the unplated surface area of ​​the end region of the lead 122 (to improve solderability). In one example, the width 248 is 0.2 mm, and the width 238 is in the range of 0.41 mm to 0.5 mm. More than 50% of the first side surface 133 of the base member 132 of the lead 122 is plated with a wettable metal for soldering [the length 274 of the shaded area 134 in FIG. 1 is longer than the length 279 of the portion 139 (unshaded area) in FIG. 1, to increase the portion of the plated side surface of the lead 122 (to improve solderability). Similarly, more than 50% of the second side surface 135 of the base member 132 of the lead 122 is plated with a wettable metal for soldering.

[0029] In the example of this disclosure, the lead 122 further includes a first notch 282 and a second notch 284, which form a protruding member 142 having a shape with a reduced width away from the base member 132. The first notch 282 is located between a first side face 133 of the base member 132 of the lead 122 and an end face 143 of the protruding member 142 of the lead 122, thereby forming a first side face of the protruding member 142 (shaded area 144 in FIG. 1). The second notch 284 is located between a second side face 135 of the base member 132 of the lead 122 and an end face 143 of the protruding member 142 of the lead 122, thereby forming a second side face 299 of the protruding member 142. The end face 143 separates the first side face (shaded area 144 in FIG. 1) and the second side face 299 of the protruding member 142. The first side (shaded area 144 in FIG1) of the protruding member 142 of the lead 122 and the second side 299 of the protruding member 142 are curved and plated with a wettable metal for soldering.

[0030] FIG2B shows a top view of the lead 250 in an example of this disclosure. The lead 250 includes a base member 252 and a protruding member 262. In one example, the thickness of the base member 252 is equal to the thickness of the protruding member 262. The protruding member 262 is directly connected to the base member 252. The protruding member 262 of the lead 250 includes a first flat side surface 264 and a second flat side surface 266 opposite to the first flat side surface 264. The base member 252 of the lead 250 includes a first flat end surface 254 and a second flat end surface 256. The first flat end surface 254 of the base member 252 is perpendicular to and directly connected to a first side surface 253 of the base member 252. The second flat end surface 256 of the base member 252 is perpendicular to and directly connected to a second side surface 255 of the base member 252. The first flat side surface 264 of the protruding member 262, the second flat side surface 266 of the protruding member 262, the first flat end surface 254 of the base member 252, and the second flat end surface 256 of the base member 252 are plated with a wettable metal for welding.

[0031] FIG3 is a top view of a semiconductor package 300 according to an example of the present disclosure. In one example, the semiconductor package 300 is a stamped quad flat no-lead (QFN) package. The semiconductor package 300 includes a lead frame 610 of FIG6, a wafer 301, and a molded package 399. The lead frame 610 includes one or more die pads 512 of FIG5A and a first set of multiple leads 320, a second set of multiple leads 340, a third set of multiple leads 360, and a fourth set of multiple leads 380. The first set of multiple leads 320 extends away from the one or more die pads 512 of FIG5A along a first direction (positive Y direction). The second set of multiple leads 340 extends away from the one or more die pads 512 of FIG5A along a second direction (negative Y direction) opposite to the first direction (positive Y direction). The third set of multiple leads 360 extends away from the one or more die pads 512 of FIG5A along a third direction (positive X direction) perpendicular to the first direction (positive Y direction). The fourth group of multiple leads 380 extends away from one or more die pads 512 in a fourth direction (negative X direction) opposite to the third direction (positive X direction) in FIG5A.

[0032] Each of the first group of multiple leads 320 includes a base member and a protruding member. For example, lead 322 includes a base member 324 and a protruding member 334. Each of the second group of multiple leads 340 includes a base member and a protruding member. For example, lead 342 includes a base member 344 and a protruding member 354. Each of the third group of multiple leads 360 includes a base member and a protruding member. For example, lead 362 includes a base member 364 and a protruding member 374. Each of the fourth group of multiple leads 380 includes a base member and a protruding member. For example, lead 382 includes a base member 384 and a protruding member 394.

[0033] The base member 324 includes a first side surface 327 and a second side surface. The protruding member 334 includes an end face. The width 339 of the end face of the protruding member 334 is less than 50% of the width 329 of the base member 324. The leads 342, 362, and 382 have similar structures. The width of the end face of the protruding member 354 is less than 50% of the width of the base member 344. The width of the end face of the protruding member 374 is less than 50% of the width of the base member 364. The width of the end face of the protruding member 394 is less than 50% of the width of the base member 384.

[0034] More than 50% of the first side surface 327 and more than 50% of the second side surface of the base member 324 are plated with a wettable metal for welding. The leads 342, 362, and 382 have similar structures. More than 50% of the first side surface and less than 50% of the second side surface of the base member 344 are plated with a wettable metal for welding. More than 50% of the first side surface and the second side surface of the base member 364 are plated with a wettable metal for solder. More than 50% of both the first and second side surfaces of the base member 384 are plated with a wettable metal for welding.

[0035] The end faces of protruding member 334, protruding member 354, protruding member 374 and protruding member 394 are not plated with metal.

[0036] Figure 4 is a flowchart of a process 400 for developing a semiconductor package in this disclosure example. The process 400 for developing a semiconductor package may begin at step 402. Figures 5A-5G show top views of the corresponding steps.

[0037] In step 402, referring now to FIG. 5A, a leadframe array 500 is provided. The leadframe array 500 includes one or more leadframes, including leadframe 510. Although only four leadframes are shown in FIG. 5A, the number of leadframes included in the leadframe array 500 can vary. The leadframe 510 includes one or more die pads 512, a first blocking strip 514, a second blocking strip 524, a first set of multiple recesses 519, a second set of multiple recesses 529, a first set of multiple leads 560, and a second set of multiple leads 580. The first blocking strip 514 includes a first set of multiple blocking strip connection portions 515. The second blocking strip 524 includes a second set of multiple blocking strip connection portions 525. The first set of multiple recesses 519 are located between the first blocking strip 514 and a first side 501 of the leadframe 510. The second set of multiple recesses 529 are located between the second blocking strip 524 and a second side 503 of the leadframe 510.

[0038] A first group of multiple leads 560 extends along a first direction (positive Y direction) away from one or more die pads 512. Each of the first group of multiple leads 560 is connected to a first stop bar 514. A second group of multiple leads 580 extends along a second direction (negative Y direction) away from one or more die blades 512. Each of the second group of multiple leads 580 is connected to a second stop bar 524.

[0039] In the examples of this disclosure, each of the first group of plurality of barrier strip connecting portions 515 includes a first end 515A, a central portion 515B, and a second end 515C. The central portion 515B is located between the first end 515A and the second end 515C. The cross-sectional area of ​​the first end 515A is smaller than the cross-sectional area of ​​the central portion 515B. The cross-sectional area of ​​the second end 515C is smaller than the cross-sectional area of ​​the central portion 515B.

[0040] In the examples of this disclosure, each of the first group of multiple barrier strip connecting portions includes a first arcuate portion and a second arcuate portion. For example, barrier strip connecting portion 513 includes a first arcuate portion 513A and a second arcuate portion 513B.

[0041] In an example of this disclosure, each of the one or more lead frames further includes a first set of multiple rectangular holes located between the first set of multiple stop bar connecting portions 515 and the one or more templates. For example, multiple rectangular holes 592 are located between the first set of multiple stop bar connecting portions 515 and one or more templates 512. The lateral dimension of each of the first set of multiple rectangular holes is smaller than the lateral dimension of the corresponding stop bar connecting portion in the first set of multiple stop bar connecting portions. For example, dimension 562 is smaller than dimension 564. In one example, dimension 562 is 0.1 mm, and dimension 564 is in the range of 0.2 to 0.3 mm.

[0042] In the example of this disclosure, the lead frame array 500 is not a pre-plated frame (PPF) array. Step 402 may be followed by step 404.

[0043] In step 404, referring now to FIG. 5B, wafer 550 is mounted on one or more die pads 512. In one example, wafer 550 is a power semiconductor transistor, such as a metal-oxide-semiconductor field-effect transistor (MOSFET). Step 404 may be followed by step 406 or step 408.

[0044] In optional step 406 (shown in dashed box), referring now to FIG. 5C, a wire bonding process and / or a clip bonding process are applied. One or more wires 552 connect the wafer 550 to the gate lead 551, and clips 556 connect the wafer 550 to the source lead 553. Step 406 may be followed by step 408.

[0045] In step 408, referring now to FIG. 5D, a molded package 598 is formed. The molded package 598 surrounds the wafer 550. Step 408 may be followed by step 410.

[0046] In step 410, referring now to FIG. 5E, a cutting or stamping process is applied. The first set of multiple stop bar connecting portions 515 of FIG. 5A is removed to form a first set of multiple grooves 575. The second set of multiple stop bar connecting portions 525 of FIG. 5A is removed to form a second set of multiple grooves 585. The width 573 of the end face of the protruding member of the lead 571 is less than 50% of the width 563 of the base member 572 of the lead 571 to reduce the unplated surface area of ​​the end region of the lead 571 (to improve solderability). Step 410 may be followed by step 412.

[0047] In step 412, referring now to FIG. 5F, a plating process is applied. The portion of the lead frame 510 not covered by the molded package 598 is plated with a wettable metal for soldering 599. In one example, step 412 is the only plating process in the semiconductor package development process 400 (no other plating processes are performed). In one example, the wettable metal 599 for soldering is tin or Sn. Step 412 may be followed by step 414.

[0048] In step 414, now referring to FIG5G, a monolithic process (along multiple dicing lines 597) is applied to form multiple semiconductor packages (e.g., semiconductor package 100 of FIG1).

[0049] The process 400 for developing semiconductor packages can also be applied to the lead frame 610 of FIG. 6. The lead frame 610 includes one or more die blades, a first blocking strip 620, a second blocking strip 630, a third blocking strip 640, a fourth blocking strip 650, a first set of multiple grooves 622, a second set of multiple grooves 632, a third set of multiple grooves 642, a fourth set of multiple grooves 652, a first set of multiple leads 624, a second set of multiple leads 634, a third set of multiple leads 644, and a fourth set of multiple leads 654.

[0050] Referring again to Figure 6, a first group of multiple leads 624 extend away from one or more die blades along a first direction (positive Y direction). Each of the multiple leads 624 in the first group is connected to a first stop bar 620. A second group of multiple leads 634 extend away from one or more die blades along a second direction (negative Y direction). Each of the multiple leads 634 in the second group is connected to a second stop bar 630. A third group of multiple leads 644 extend away from one or more die blades along a third direction (positive X direction). Each of the multiple leads 644 in the third group is connected to a third stop bar 640. A fourth group of multiple leads 654 extend away from one or more die blades along a fourth direction (negative X direction). Each of the multiple leads 654 in the fourth group is connected to a fourth stop bar 650.

[0051] Each of the plurality of leads 624 in the first group includes a base member and a protruding member. For example, lead 628 includes a base member 627 and a protruding member 629. Each of the plurality of leads 634 in the second group includes a base member and a protruding member. Each of the plurality of leads 644 in the third group includes a base member and a protruding member. Each of the plurality of leads 654 in the fourth group includes a base member and a protruding member.

[0052] The process 400 for developing a semiconductor package can also be applied to the lead frame array 700 of FIG. 7. The lead frame array 700 includes one or more lead frames, each including a lead frame 710. The lead frame 710 includes one or more die blades, a first stop bar 720, a second stop bar 730, a first set of multiple recesses 722, a second set of multiple recesses 732, a first set of multiple holes 729, a second set of multiple holes 739, a first set of multiple leads 724 (extending along the positive Y direction), and a second set of multiple leads 734 (extending along the negative Y direction). Each of the first set of multiple holes 729 is located between a corresponding pair of recesses of the first set of multiple recesses 722. Each of the second set of multiple holes 739 is located between a corresponding pair of recesses of the second set of multiple recesses 732. In one example, each of the first set of multiple holes 729 and the second set of multiple holes 739 is circular. In another example, each of the first set of multiple holes 729 and the second set of multiple holes 739 is "+" shaped. After all steps of the semiconductor package development process 400 are completed, the end faces of the lead tips 798 of the first set of multiple vias 729 and the first set of multiple leads 724 will be plated. The end faces of the lead tips 799 of the second set of multiple vias 739 will be plated.

[0053] Those skilled in the art will recognize that modifications to the embodiments disclosed herein are possible. For example, the number of leads may vary. Other modifications can be made by those skilled in the art, and all such modifications are considered to fall within the scope of the invention as defined in the claims.

[0054] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims. [Simplified Explanation of the Diagram]

[0022] Figure 1 shows a perspective view of a semiconductor package according to an example of this disclosure. Figure 2A shows a top view of a lead in an example of this disclosure. Figure 2B shows a top view of another lead in an example of this disclosure. Figure 3 is a top view of another semiconductor package according to an example of this disclosure. Figure 4 is a flowchart of the process of developing a semiconductor package according to an example of this disclosure. Figures 5A, 5B, 5C, 5D, 5E, 5F and 5G show the process steps of manufacturing a semiconductor package according to an example of this disclosure. Figure 6 shows a top view of yet another lead frame according to an example of this disclosure. Figure 7 shows a top view of a lead frame array according to an example of this disclosure.

Claims

1. A semiconductor package, comprising: A leadframe includes: one or more die pads; and a first set of multiple leads extending from the one or more die pads along a first direction, each of the first set of multiple leads including: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the first set of multiple leads, the protruding member of the first set of multiple leads including: an end face; a die attached to the one or more die pads of the leadframe; and a molded package for encapsulating the die; wherein the width of the end face of the protruding member of each of the first set of multiple leads is less than 50% of the width of the base member of each of the first set of multiple leads; and wherein the end face of the protruding member of each of the first set of multiple leads is not plated with a wettable metal for soldering.

2. The semiconductor package as claimed in claim 1, wherein more than 50% of the first side surface of the base member of each of the first set of plurality of leads and more than 50% of the second side surface of the base member of each of the first set of plurality of leads are plated with a wettable metal for soldering.

3. The semiconductor package as claimed in claim 1, wherein each of the plurality of leads in the first group further comprises: A first notch is located between a first side surface of the base member of each of the first group of multiple leads and an end face of the protruding member of each of the first group of multiple leads; and a second notch is located between a second side surface of the base member of each of the first group of multiple leads and an end face of the protruding member of each of the first group of multiple leads; wherein the surfaces of the first notch and the second notch of each of the first group of multiple leads are plated with a wettable metal for soldering.

4. The semiconductor package as claimed in claim 1, wherein the protruding member of each of the first group of plurality of leads further comprises: A first flat side surface; And a second flat side surface opposite to the first flat side surface; The base component of each of the first group of multiple leads further includes: a first flat end surface, which is perpendicular to and directly connected to a first side surface of the base component of each of the first group of multiple leads; and a second flat end surface, which is perpendicular to and directly connected to a second side surface of the base component of each of the first group of multiple leads; wherein the first flat side surface of the protruding component of each of the first group of multiple leads, the second flat side surface of the protruding component of each of the first group of multiple leads, the first flat end surface of the base component of each of the first group of multiple leads, and the second flat end surface of the base component of each of the first group of multiple leads are all plated with a wettable metal for soldering.

5. The semiconductor package as claimed in claim 1, further comprising a second set of plurality of leads extending away from the one or more die pads along a second direction opposite to the first direction, each of the second set of plurality of leads comprising: A base member includes: a first side surface; a second side surface; and a protruding member directly connected to the base member of a second set of multiple leads, the protruding member of the second set of multiple leads including: an end face; wherein the width of the end face of the protruding member of each of the second set of multiple leads is less than 50% of the width of the base member of each of the second set of multiple leads; wherein more than 50% of the first side surface and more than 50% of the second side surface of the base member of each of the second set of multiple leads are plated with a wettable metal for soldering; and wherein the end face of the protruding member of each of the second set of multiple leads is not plated with a wettable metal for soldering.

6. The semiconductor package as claimed in claim 5, wherein each of the plurality of leads in the second set further comprises: A first notch is located between a first side surface of the base member of each of the second set of multiple leads and an end face of the protruding member of each of the second set of multiple leads; A second notch is provided, located between the second side surface of the base member of each of the second set of multiple leads and the end face of the protruding member of each of the second set of multiple leads; and wherein the surfaces of the first notch of each of the second set of multiple leads and the surfaces of the second notch of each of the second set of multiple leads are plated with a wettable metal for soldering.

7. The semiconductor package as claimed in claim 5, wherein the protruding member of each of the second set of plurality of leads further comprises: A first flat side surface; And a second flat side surface opposite to the first flat side surface; The base component of each of the second group of multiple leads further includes: a first flat end surface perpendicular to and directly connected to a first side surface of the base component of each of the second group of multiple leads; a base and a second flat end surface perpendicular to and directly connected to a second side surface of the base component of each of the second group of multiple leads; wherein the first flat side surface of the protruding component of each of the second group of multiple leads, the second flat side surface of the protruding component of each of the second group of multiple leads, the first flat end surface of the base component of each of the second group of multiple leads, and the second flat end surface of the base component of each of the second group of multiple leads are all plated with a wettable metal for soldering.

8. The semiconductor package as claimed in claim 5, wherein the lead frame further comprises: A third group of multiple leads extending away from the one or more die pads along a third direction perpendicular to a first direction, each of the third group of multiple leads comprising: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the third group of multiple leads, the protruding member of the third group of multiple leads comprising: an end face; and a fourth group of multiple leads extending away from the one or more die pads along a fourth direction opposite to the third direction, each of the fourth group of multiple leads comprising: a base member including: a first side surface; and a second side surface; and a protruding member directly connected to the base member of the fourth group of multiple leads, the protruding member of the fourth group of multiple leads comprising: an end face; wherein the width of the end face of the protruding member of each of the third group of multiple leads is less than 50% of the width of the base member of each of the third group of multiple leads; In the third group of multiple leads, at least 50% of the first side surface of the base member of each lead and at least 50% of the second side surface of the base member of each lead in the third group of multiple leads are plated with a wettable metal for welding; wherein the end face of the protruding member of each lead in the third group of multiple leads is not plated with a wettable metal for welding; wherein the width of the end face of the protruding member of each lead in the fourth group of multiple leads is less than 50% of the width of the base member of each lead in the fourth group of multiple leads; wherein at least 50% of the first side surface of the base member of each lead in the fourth group of multiple leads and at least 50% of the second side surface of the base member of each lead in the fourth group of multiple leads are plated with a wettable metal for welding; and wherein the end face of the protruding member of each lead in the fourth group of multiple leads is not plated with a wettable metal for welding.

9. A method for manufacturing a semiconductor package, the method comprising the following steps: A leadframe array is provided, the leadframe array comprising: one or more leadframes, each leadframe including one or more die pads; a first blocking strip including: a first set of multiple blocking strip connection portions; a second blocking strip including: a second set of multiple blocking strip connection portions; a first set of multiple grooves located between the first blocking strip and a first side of each leadframe; a second set of multiple grooves located between the second blocking strip and a second side of each leadframe, the second side of each leadframe opposite to the first side of each pinframe; a first set of multiple leads extending along a first direction away from one or more die pads, each of the first set of multiple leads being connected to the first blocking strip; and a second set of multiple leads extending along a second direction opposite to the first direction away from one or more die pads, each of the second set of multiple leads being connected to the second blocking strip; mounting a die on one or more die pads; forming a molded package of the packaged die; and removing the first set of multiple blocking strip connection portions and the second set of multiple blocking strip connection portions by applying a dicing or stamping process. Tin plating is performed on the portion of the leadframe array not covered by the molded package; and a monolithic process is applied.

10. The method of claim 9, wherein a wire bonding process or a clip bonding process is applied prior to the step of forming the molded package.

11. The method of claim 9, wherein each of the first group of plurality of barrier strip connecting portions and the second group of plurality of barrier strip connecting portions comprises: A first end; a central portion; and a second end opposite to the first end; wherein the cross-sectional area of ​​the first end is smaller than the cross-sectional area of ​​the central portion; and wherein the cross-sectional area of ​​the second end is smaller than the cross-sectional area of ​​the central portion.

12. The method as described in claim 9, wherein each of the plurality of leads in the first group comprises: A base component; And a protruding member that is directly connected to the base member of the first set of multiple leads; The width of the protruding member of each of the first group of multiple leads is less than 50% of the width of the base member of each of the first group of multiple leads; wherein each of the second group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the second group of multiple leads; and wherein the width of the protruding member of each of the second group of multiple leads is less than 50% of the width of the base member of each of the second group of multiple leads.

13. The method as described in claim 9, wherein each of the plurality of barrier strip connecting portions in the first group comprises: A first arc-shaped section; And a second arc-shaped portion; Each of the second group of multiple barrier strip connecting portions includes: a first arc-shaped portion; and a second arc-shaped portion.

14. The method of claim 9, wherein each of the one or more lead frames further comprises: A first group of rectangular holes is located between a first group of multiple barrier strip connecting portions and one or more die pads; wherein the lateral dimension of each of the first group of multiple rectangular holes is smaller than the lateral dimension of the corresponding barrier strip connecting portion in the first group of multiple barrier strip connecting portions.

15. The method of claim 9, wherein each of the one or more lead frames further comprises: A third blocking strip includes: a third group of multiple blocking strip connecting portions; a fourth blocking strip includes: a fourth group of multiple blocking strip connecting portions; a third group of multiple grooves located between the third blocking strip and a third side of each lead frame; a fourth group of multiple grooves located between the fourth blocking strip and a fourth side of each lead frame, the fourth side of each lead frame being opposite to the third side of each lead frame; a third group of multiple leads extending away from one or more die pads along a third direction perpendicular to a first direction, each of the third group of multiple leads being connected to the third blocking strip; and a fourth group of multiple leads extending away from one or more die pads along a fourth direction opposite to the third direction, each of the fourth group of multiple leads being connected to the fourth blocking strip; and wherein the application of a cutting or stamping process further removes the third group of multiple blocking strip connecting portions and the fourth group of multiple blocking strip connecting portions.

16. The method of claim 15, wherein each of the plurality of leads in the third group comprises: A base component; A base member and a protruding member directly connected to the base member of the third group of multiple leads; wherein the width of the protruding member of each of the third group of multiple leads is less than 50% of the width of the base member of each of the third group of multiple leads; wherein each of the fourth group of multiple leads includes: a base member; and a protruding member directly connected to the base member of the fourth group of multiple leads; and wherein the width of the protruding member of each of the fourth group of multiple leads is less than 50% of the width of the base member of each of the fourth group of multiple leads.

17. The method of claim 9, wherein each of the one or more lead frames further comprises: The first group has multiple holes, each hole located between a pair of grooves in the first group of grooves; And a second set of multiple holes, each of which is located between a corresponding pair of grooves in the second set of multiple grooves.

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