This U.S. nonprovisional application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0141004, filed on Oct. 21, 2021, in the Korean Intellectual Property Office, the disclosure of which is hereby incorporated by reference in its entirety.
Embodiments relate to semiconductor packages, and more particularly, to bumps of semiconductor packages.
Semiconductor devices have been rapidly developed to increase the number of electrode terminals and to decrease a pitch between the electrode terminals. Therefore, research has been increasingly conducted into reducing semiconductor devices. Semiconductor devices generally have electrical connection terminals, e.g., solder balls or bumps, for electrical connections with other electronic devices or printed circuit boards. Semiconductor devices require fine pitches between the electrical connection terminals thereof.
According to some embodiments, a semiconductor package may include a package substrate; a semiconductor chip mounted on the package substrate; a connection solder pattern between the package substrate and the semiconductor chip; and a dummy bump between the package substrate and the semiconductor chip, the dummy bump being spaced apart from the connection solder pattern. The connection solder pattern may include a first intermetallic compound layer, a connection solder layer, and a second intermetallic compound layer. The dummy bump may include a dummy pillar and a dummy solder pattern. A thickness of the dummy solder pattern may be less than a thickness of the connection solder pattern. A melting point of the dummy solder pattern may be greater than a melting point of the connection solder layer.
According to some embodiments, a semiconductor package may include a package substrate; a semiconductor chip mounted on the package substrate; a connection bump between the package substrate and the semiconductor chip, the connection bump including a connection solder layer; and a dummy bump between the package substrate and the semiconductor chip, the dummy bump being spaced apart from the connection bump. The connection solder layer may include a first solder material. The dummy bump may include: a dummy pillar; and a dummy solder pattern on the dummy pillar. The dummy solder pattern may include an intermetallic compound including a second solder material different from the first solder material. A melting point of the dummy solder pattern may be greater than a melting point of the connection solder layer.
According to some embodiments, a semiconductor package may include a package substrate that includes a connection substrate pad and a dummy substrate pad, the connection substrate pad and the dummy substrate pad being on a top surface of the package substrate; a plurality of solder balls on a bottom surface of the package substrate; a semiconductor chip mounted on the top surface of the package substrate, the semiconductor chip including a dummy chip pad and a connection chip pad on the bottom surface of the semiconductor chip; a molding layer on the top surface of the package substrate, the molding layer covering the semiconductor chip; a plurality of connection bumps between the connection substrate pad and the connection chip pad; and a dummy bump between the dummy substrate pad and the dummy chip pad, the dummy bump being spaced apart from the connection bumps. Each of the connection bumps may include: a connection pillar; and a connection solder pattern on one surface of the connection pillar. The connection solder pattern may include a first intermetallic compound layer, a connection solder layer, and a second intermetallic compound layer. The dummy bump may include: a dummy pillar; and a dummy solder pattern on one surface of the dummy pillar. The connection solder layer may include a first solder material. The dummy solder pattern may include an intermetallic compound including a second solder material different from the first solder material. A thickness of the dummy solder pattern may be less than a thickness of the connection solder pattern.
Features will become apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:
A semiconductor package and a method of fabricating the same according to example embodiments will be described hereinafter.
Referring to
The first direction D1 may be parallel to a top surface of the package substrate 100. The first direction D1 may be a diagonal direction, e.g., the first direction D1 may not be parallel to lateral surfaces of the package substrate 100. The second direction D2 may be substantially perpendicular to the top surface of the package substrate 100. The phrase “two components are laterally spaced apart from each other” means that “two components are horizontally spaced apart from each other.” The term “horizontal” means being parallel to the top surface of the package substrate 100, e.g., the term “horizontal” may include the meaning of being parallel to the first direction D1. The term “perpendicular” means being parallel to the second direction D2.
The package substrate 100 may include, e.g., a printed circuit board (PCB). Alternatively, a redistribution layer may be used as the package substrate 100. The package substrate 100 may include connection substrate pads 111, dummy substrate pads 112, internal lines 130, and lower pads 140.
The lower pads 140 may be provided on a bottom surface of the package substrate 100. The lower pads 140 may serve as pads for the solder balls 500.
The internal lines 130 may be provided in the package substrate 100, thereby being coupled to the lower pads 140. The internal lines 130 and the lower pads 140 may include a conductive material, e.g., metal.
The connection substrate pads 111 may be provided on the top surface of the package substrate 100. The top surface of the package substrate 100 may stand opposite to the bottom surface of the package substrate 100, e.g., the top surface of the package substrate 100 may face the semiconductor chip 200. The connection substrate pads 111 may be electrically connected through the internal lines 130 to the lower pads 140. The phrase “electrically connected to a certain component” means being directly connected to a certain component or indirectly connected through other conductive component(s) to a certain component. The connection substrate pads 111 may include metal, e.g., one or more of copper, aluminum, and tungsten.
The dummy substrate pads 112 may be provided on the top surface of the package substrate 100 and may be disposed laterally spaced apart from the connection substrate pads 111, e.g., the dummy substrate pads 112 and the connection substrate pads 111 may overlap different portions of the top surface of the package substrate 100. The dummy substrate pads 112 may not be electrically connected to the internal lines 130 while being spaced apart from the internal lines 130. The dummy substrate pads 112 may not be electrically connected to the solder balls 500. The dummy substrate pads 112 may include metal, e.g., one or more of copper, aluminum, and tungsten. The dummy substrate pads 112 may include metal the same as or different from that of the connection substrate pads 111.
The solder balls 500 may be disposed on the bottom surface of the package substrate 100. For example, the solder balls 500 may be correspondingly disposed on bottom surfaces of the lower pads 140 and may be correspondingly coupled to the lower pads 140, e.g., in one-to-one correspondence. The solder balls 500 may be electrically connected to the connection substrate pads 111 and the dummy substrate pads 112. The solder balls 500 may be electrically separated from each other. The solder balls 500 may include a solder material. The solder material may include, e.g., tin, bismuth, lead, silver, or any alloy thereof.
The semiconductor chip 200 may be mounted on the top surface of the package substrate 100. When viewed in a plan view, as shown in
The semiconductor chip 200 may be, e.g., a memory chip, a logic chip, or a buffer chip. As shown in
The semiconductor substrate 210 may include a semiconductor material, e.g., silicon, germanium, or silicon-germanium. The semiconductor substrate 210 may have a top surface that correspond to that of the semiconductor chip 200.
The integrated circuits 215 may be provided on the bottom surface of the semiconductor substrate 210. The integrated circuits 215 may include, e.g., transistors.
The wiring layer 220 may be provided on the bottom surface of the semiconductor substrate 210, e.g., the wiring layer 220 may be between the bottom surface of the semiconductor substrate 210 and the package substrate 100. The wiring layer 220 may include a dielectric layer 221 and wiring structures 223. The dielectric layer 221 may be provided on the bottom surface of the semiconductor substrate 210, thereby covering the integrated circuits 215. The dielectric layer 221 may be a multiple layer. The dielectric layer 221 may include a silicon-containing dielectric material. The silicon-containing dielectric material may include, e.g., one or more of silicon oxide, silicon nitride, silicon oxynitride, and tetraethyl orthosilicate (TEOS). The wiring structures 223 may be provided in the dielectric layer 221. The wiring structures 223 may be electrically connected to the integrated circuits 215. The phrase “a certain component is electrically connected to the semiconductor chip 200” means that a certain component is electrically connected through the connection chip pads 251 of the semiconductor chip 200 to the integrated circuits 215 of the semiconductor chip 200. The wiring structures 223 may include wire parts and via parts connected to the wire parts. A bottom surface of the wiring layer 220 may be a bottom surface of the semiconductor chip 200.
The dummy chip pads 252 may be provided on the bottom surface at the second region R2 of the semiconductor chip 200. For example, the dummy chip pads 252 may be provided on the first edge regions ER1 of the semiconductor chip 200. The dummy chip pads 252 may include a first metal element. The first metal element may include one or more of, e.g., copper, aluminum, nickel, gold, and palladium. For example, as shown in
The connection chip pads 251 may be provided on the bottom surface at the first region R1 of the semiconductor chip 200. The connection chip pads 251 may be disposed laterally spaced apart from the dummy chip pads 252. The connection chip pads 251 may be electrically connected through the wiring structures 223 to the integrated circuits 215. The connection chip pads 251 may be disposed spaced apart from each other. The connection chip pads 251 may include one or more of, e.g., copper, aluminum, palladium, nickel, and gold.
The connection bumps 310 may be interposed between the package substrate 100 and the first region R1 of the semiconductor chip 200. For example, the connection bumps 310 may be interposed between and electrically connected to the connection substrate pads 111 and the connection chip pads 251. Therefore, the semiconductor chip 200 may be electrically connected through the connection bumps 310 to the package substrate 100. For brevity of description, the following will discuss a single connection chip pad 251, a single dummy chip pad 252, a single connection substrate pad 111, and a single dummy substrate pad 112.
Each of the connection bumps 310 may include a connection pillar 312 and a connection solder pattern 315. The connection pillar 312 may be provided on a bottom surface of the connection chip pad 251 that corresponds thereto. The connection pillar 312 may have a cylindrical shape. The connection pillar 312 may include a metal element, e.g., copper or tungsten. The connection pillar 312 may have a first height H1.
The connection solder pattern 315 may be provided on a bottom surface of the connection pillar 312. The connection solder pattern 315 may be interposed between and electrically connected to the connection pillar 312 and the connection substrate pad 111.
The connection solder pattern 315 may include a first solder material. The first solder material may include one or more of, e.g., tin (Sn), silver (Ag), copper (Cu), manganese (Mg), lead (Pb), and any alloy thereof. A primary element of the first solder material may be, e.g., tin. A primary element of a certain component may have an amount greater than any other element present in the certain component. For example, the tin may have an amount of about 50 wt % of the first solder material, e.g., 50 wt % based on a total weight of the first solder material. The first solder material may have a melting point of about 210° C. to about 240° C.
The dummy bumps 320 may be provided between the package substrate 100 and the second region R2 of the semiconductor chip 200. For example, the dummy bumps 320 may be provided on the first edge regions ER1 of the semiconductor chip 200. The dummy bumps 320 may be interposed between the dummy substrate pads 112 and the dummy chip pads 252. As shown in
Each of the dummy bumps 320 may include a dummy pillar 322 and a dummy solder pattern 325. The dummy pillar 322 may be provided on a top surface of the dummy substrate pad 112 that corresponds thereto. The dummy pillar 322 may have a cylindrical shape. For example, the dummy pillar 322 may have a circular shape when viewed in a plan view, as shown in
The dummy solder pattern 325 may be provided on the dummy pillar 322. For example, the dummy solder pattern 325 may be interposed between the dummy pillar 322 and the dummy chip pad 252. The dummy solder pattern 325 may be in direct contact with the dummy pillar 322 and the dummy chip pad 252. The dummy solder pattern 325 may include an intermetallic compound (IMC). The dummy solder pattern 325 may be electrically connected to the dummy pillar 322 and the dummy chip pad 252.
With reference to
The connection bump 310 may include the connection pillar 312 and the connection solder pattern 315. The connection solder pattern 315 may include a first intermetallic compound layer 316, a connection solder layer 315S, and a second intermetallic compound layer 317.
The first intermetallic compound layer 316 may be provided on a bottom surface of the connection solder layer 315S. The first intermetallic compound layer 316 may be in contact with the connection substrate pad 111 and the connection solder layer 315S. The first intermetallic compound layer 316 may include an intermetallic compound including, e.g., consisting of, the first solder material and metal contained in the connection substrate pad 111. The second intermetallic compound layer 317 may be provided on a top surface of the connection solder layer 315S. The second intermetallic compound layer 317 may be in contact with the connection solder layer 315S and the connection pillar 312. The second intermetallic compound layer 317 may include an intermetallic compound including, e.g., consisting of, the first solder material and metal contained in the connection pillar 312.
The connection solder layer 315S may be interposed between the first intermetallic compound layer 316 and the second intermetallic compound layer 317. The connection solder layer 315S may include the first solder material but may not include an intermetallic compound. For example, the connection solder layer 315S may be a remaining portion that is not formed into an intermetallic compound in a reflow process. The first solder material may be that discussed above. Therefore, the connection solder layer 315S may have a same melting point as that of the first solder material. The melting point of the connection solder layer 315S may range from about 210° C. to about 240° C. The melting point of the connection solder layer 315S may be lower than that of the first intermetallic compound layer 316 and that of the second intermetallic compound layer 317. The connection solder layer 315S may have a thickness greater than that of the first intermetallic compound layer 316 and that of the second intermetallic compound layer 317.
The connection solder pattern 315 may have a first thickness T1, e.g., along the second direction D2. The first thickness T1 may be the same as a sum of the thicknesses of the first intermetallic compound layer 316, the connection solder layer 315S, and the second intermetallic compound layer 317. The connection pillar 312 may have a first height H1, e.g., along the second direction D2. In some embodiments, the connection bump 310 may not include any of the first intermetallic compound layer 316 and the second intermetallic compound layer 317.
For brevity in figures other than
The dummy bump 320 may include the dummy pillar 322 and the dummy solder pattern 325. The dummy pillar 322 may have a second height H2, e.g., along the second direction D2. The second height H2 may be less than the first height H1.
The dummy solder pattern 325 may include an intermetallic compound including, e.g., consisting of, a second metal element contained in the dummy pillar 322, a first metal element contained in the dummy chip pad 252, and a second solder material. The intermetallic compound may be an alloy in which the first metal element, the second metal element, and the second solder material are combined with each other at a certain stoichiometric ratio. The intermetallic compound may have physical chemical properties different from those of the first metal element, the second metal element, and the second solder material. The dummy solder pattern 325 may not include the second solder material that does not participate in the formation of the intermetallic compound. The second solder material may be different from the first solder material. The second solder material may include one or more of, e.g., bismuth (Bi), indium (In), and any alloy thereof. A primary element of the second solder material may include, e.g., bismuth (Bi) or indium (In). For example, a content ratio of bismuth or indium may be equal to or greater than about 20 wt % of the second solder material. The content ratio of bismuth or indium may be equal to or greater than about 20 wt % of the dummy solder pattern 325.
The dummy solder pattern 325 may have a melting point substantially the same as that of an intermetallic compound including, e.g., consisting of, the first metal element, the second metal element, and the second solder material. The dummy solder pattern 325 may include the intermetallic compound and may have a relatively high melting point. The melting point of the dummy solder pattern 325 may be higher than that of the connection solder pattern 315. The melting point of the dummy solder pattern 325 may be equal to or higher than about 270° C. For example, the melting point of the dummy solder pattern 325 may range from about 270° C. to about 3,000° C.
The dummy solder pattern 325 may have a second thickness T2, e.g., along the second direction D2. The second thickness T2 may be less than, e.g., each of, the first thickness T1 and the second height H2. For example, the second thickness T2 may range from about 5 μm to about 10 μm.
A sum of the second thickness T2 and the second height H2 may be substantially the same as a sum of the first thickness T1 and the first height H1. The phrase “certain components are the same in terms of width, height, and level” may include an allowable tolerance possibly occurring during fabrication process.
Referring back to
The molding layer 400 may be provided on the top surface of the package substrate 100, thereby covering the semiconductor chip 200. The molding layer 400 may include a dielectric polymer, e.g., an epoxy-based molding compound. Alternatively, the under-fill layer 410 may be omitted, and the molding layer 400 may further extend between the package substrate 100 and the semiconductor chip 200 to encapsulate the dummy bumps 320 and the connection bumps 310.
Referring to
For example, the first connection solder part 315B may be provided on the connection substrate pad 111. The first connection solder part 315B may include a first solder material.
The dummy pillar 322 may be disposed on the dummy substrate pad 112. The dummy solder part 325S may be provided on the dummy pillar 322. The dummy solder part 325S may have a thickness T2′ substantially the same as the second thickness T2 of the dummy solder pattern 325 shown in
The dummy solder part 325S may include a second solder material that does not participate in the formation of an intermetallic compound. The second solder material may be different from the first solder material. The dummy solder part 325S may have a melting point lower than that of the first connection solder part 315B. The melting point of the dummy solder part 325S may be lower than about 210° C. For example, the melting point of the dummy solder part 325S may range from about 100° C. to about 180° C. The dummy solder part 325S may include an indium-based solder material or a bismuth-based solder material.
The semiconductor device 20 may include the semiconductor chip 200 and a conductive connection bump 310A. The semiconductor chip 200 may be substantially the same as that discussed in the examples of
The connection pillar 312 may be substantially the same as the connection pillar 312 of
The semiconductor chip 200 may be placed on a top surface of the package substrate 100. The placement of the semiconductor device 20 may be performed at room temperature (e.g., about 27° C.). The semiconductor chip 200 may have a curved shape, e.g., a crying face shape, at room temperature. For example, the semiconductor chip 200 may have an upwardly convex shape when viewed in cross section, e.g., a center of the semiconductor chip 200 may curve (e.g., bulge) out in an upward direction away from the package substrate 100 to define a convex shape in a cross section. A bottom surface at the second region R2 of the semiconductor chip 200 may be located at a lower level than that of a bottom surface at the first region R1 of the semiconductor chip 200. A level of a certain component may indicate a vertical level, e.g., a vertical distance along the second direction D2 relative to a bottom of the package substrate 100. A difference in level between two components may be measured in the second direction D2. The conductive connection bump 310A and the dummy chip pad 252 may be vertically aligned with the first connection solder part 315B and the dummy solder part 325S, respectively.
Referring to
The first temperature may be higher than the melting point of the dummy solder part 325S. Therefore, the dummy solder part 325S may be melted. A transient liquid phase bonding process may be used to allow the dummy solder part 325S to convert into the dummy solder pattern 325. The transient liquid phase bonding may be a transient liquid phase diffusion connection. The dummy solder pattern 325 may be bonded to the dummy chip pad 252 and the dummy pillar 322. With reference to
Referring to
Referring to
When the dummy solder part 325S has a thickness (see T2′ of
The first and second connection solder parts 315B and 315A may have their melting points higher than the first temperature. During the transient liquid phase bonding process, the first and second connection solder parts 315B and 315A may not be bonded to each other.
Referring to
In a procedure for forming the connection solder pattern 315, a metal element in the connection pillar 312 may migrate into the second connection solder part 315A to react with the second solder material. Therefore, the second intermetallic compound layer 317 may be formed. A metal element in the connection substrate pad 111 may migrate into the first connection solder part 315B to react with the first solder material. Therefore, the first intermetallic compound layer 316 may be formed. The connection solder layer 315S may be interposed between the first intermetallic compound layer 316 and the second intermetallic compound layer 317. A portion of the first solder material may not be formed into an intermetallic compound, but may remain to form the connection solder pattern 315.
Referring to
In contrast, according to example embodiments, the dummy bump 320 are formed via the transient liquid phase bonding process under conditions of the first temperature (which is lower than the second temperature required for reflow), so the second solder material included in the dummy solder part 325S may be formed into the dummy solder pattern 325 (which includes an intermetallic compound with an extremely high melting point). Therefore, the dummy bump 320 secures a connection between edges of the semiconductor chip 200 and the package substrate 100 during a subsequent reflow process even at high temperatures, due to the high melting point of the resultant intermetallic compound in the dummy solder pattern 325.
Referring back to
In detail, as warpage (discussed with reference to
When the second thickness T2 of the dummy solder pattern 325 is less than about 5 μm, a reduced bonding force may be provided between the dummy solder pattern 325 and the semiconductor chip 200, and between the dummy solder pattern 325 and the package substrate 100. In this case, during the reflow process, it may be difficult for the dummy solder pattern 325 to prevent the warpage of the semiconductor package 1. When the second thickness T2 of the dummy solder pattern 325 is greater than about 10 μm, the dummy solder part 325S of
According to some embodiments, because the second thickness T2 is in a range of about 5 μm to about 10 μm, the dummy solder pattern 325 may stably fix the semiconductor chip 200 to the package substrate 100. Accordingly, it may be possible to satisfactorily bond the first and second connection solder parts 315B and 315A to each other and to prevent failure during the fabrication process of the semiconductor package 1.
Referring to
Referring back to
The following will discuss a single semiconductor package 1 for brevity of description, but a method of fabricating a semiconductor package is not limited to a chip-level fabrication. An arrangement of dummy pillars will be discussed in detail according to some embodiments.
Referring to
As shown in
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The embodiments of
The following will describe a substrate structure and a semiconductor device according to some embodiments with reference to
Referring to
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The substrate structure 10 may include the package substrate 100 and the first connection solder part 315B. Differently from that shown, the first connection solder part 315B may be omitted.
Referring to
The connection bump 310 may include the connection solder pattern 315 and the connection pillar 312. The first thickness T1 of the connection solder pattern 315 may be greater than the second thickness T2 of the dummy solder pattern 325. A sum of the second thickness T2 and the second height H2 may be substantially the same as that of the first thickness T1 and the first height H1. The solder balls 500 may be attached to a bottom surface of the package substrate 100, and thus a semiconductor package lA may be fabricated.
Referring to
The substrate structure 10 may include the package substrate 100, the first connection solder part 315B, a lower dummy pillar 322B, and a lower dummy solder part 325SB. The lower dummy pillar 322B may include one or more of the materials discussed in the example of the dummy pillar 322 shown in
Referring to
A sum of a height H4 of the lower dummy pillar 322B, a height H3 of the upper dummy pillar 322A, and the second thickness T2 may be substantially the same as that of the first thickness T1 and the first height H1. A sum of the height H4 of the lower dummy pillar 322B and the height H3 of the upper dummy pillar 322A may be greater than the first height H1. The second thickness T2 may be the same as that discussed in
By way of summation and review, embodiments provide a semiconductor package with reduced defects and a method of fabricating the same. That is, according to example embodiments, a semiconductor package may include a dummy bump and a connection bump. The dummy bump may include a dummy pillar and a dummy solder pattern. The dummy solder pattern may be formed by a transient liquid phase bonding process, and may include an intermetallic compound. The connection bump may include a connection pillar and a connection solder. During a reflow process for forming a connection solder pattern, the dummy bump may prevent warpage of a semiconductor chip. Therefore, the connection solder may be satisfactorily connected to a package substrate and the semiconductor chip. The occurrence of defects may be prevented during fabrication process for the semiconductor package.
Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
Number | Date | Country | Kind |
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10-2021-0141004 | Oct 2021 | KR | national |