SEMICONDUCTOR PACKAGE WITH IMPROVED CONNECTION OF THE PINS TO THE BOND PADS OF THE SEMICONDUCTOR DIE

Abstract

A semiconductor package including a semiconductor die having multiple bond pads is provided. The package further includes an electrically conducting clip including, at a first side thereof, at least one pin for mounting the package to an external board and includes, at a second side opposite to the first side, a connecting portion connecting the clip to at least two bond pads of the multiple bond pads. The connection portion includes at least two elongated connecting strips spaced apart from each other at a distance in such a manner that each strip extends over at least one of the at least two bond pads and is connected thereto.

Claims

1. A semiconductor package comprising a semiconductor die having multiple bond pads, the package further comprising an electrically conducting clip, wherein the clip comprises, at a first side thereof, at least one pin for mounting the package to an external board and comprises, at a second side opposite to the first side, a connecting portion connecting the clip to at least two bond pads of the multiple bond pads, the connection portion comprising: at least two elongated connecting strips spaced apart from each other at a distance so that each strip extends over at least one of the at least two bond pads and is connected thereto.

2. The semiconductor package in accordance with claim 1, wherein each of the elongated strips has a length in a longitudinal direction of the strips that is larger than a dimension of the bond pads seen in the longitudinal direction.

3. The semiconductor package in accordance with claim 1, wherein the clip comprises a bridge portion connecting free ends of the at least two elongated connecting strips to one another.

4. The semiconductor package in accordance with claim 1, wherein the at least two elongated connecting strips extend parallel to one another.

5. The semiconductor package in accordance with claim 1, wherein semiconductor die is selected from the group consisting of: a Field Effect Transistor (FET), wherein the at least two bond pads are at least two drain bond pads of the FET; and a High-Electron-Mobility Transistor (HEMT), wherein the at least two bond pads are at least two drain bond pads of the HEMT.

6. The semiconductor package in accordance with claim 1, wherein each strip extends over and connects to exactly one of the at least two bond pads.

7. The semiconductor package in accordance with claim 1, wherein the strip comprises a base part in between the connecting portion and the at least one pin, and wherein the base part is elevated with respect to a part of the elongated connecting strips with which respective part the elongated connecting strips are connected to the corresponding bond pads.

8. The semiconductor package in accordance with claim 1, wherein each of the at least two elongated strips has a width that correspond to a width of each of the at least two bond pads.

9. The semiconductor package in accordance with claim 2, wherein the length of the elongated strips is between 1.5×-4× larger than the dimension of the bond pads, in the longitudinal direction.

10. The semiconductor package in accordance with claim 2, wherein the clip comprises a bridge portion connecting free ends of the at least two elongated connecting strips to one another.

11. The semiconductor package in accordance with claim 2, wherein the at least two elongated connecting strips extend parallel to one another.

12. The semiconductor package in accordance with claim 2, wherein semiconductor die is selected from the group consisting of: a Field Effect Transistor (FET), wherein the at least two bond pads are at least two drain bond pads of the FET; and a High-Electron-Mobility Transistor (HEMT), wherein the at least two bond pads are at least two drain bond pads of the HEMT.

13. The semiconductor package in accordance with claim 2, wherein each strip extends over and connects to exactly one of the at least two bond pads.

14. The semiconductor package in accordance with claim 2, wherein the strip comprises a base part in between the connecting portion and the at least one pin, and wherein the base part is elevated with respect to a part of the elongated connecting strips with which respective part the elongated connecting strips are connected to the corresponding bond pads.

15. The semiconductor package in accordance with claim 2, wherein each of the at least two elongated strips has a width that correspond to a width of each of the at least two bond pads.

16. The semiconductor package in accordance with claim 3, wherein the bridge portion is elevated with respect to a part of the elongated connecting strips with which respective part the elongated connecting strips are connected to the corresponding bond pads.

17. The semiconductor package in accordance with claim 3, wherein the bridge portion is provided at a distance from the bond pads seen in a longitudinal direction of the connecting strips.

18. The semiconductor package in accordance with claim 16, wherein the bridge portion is provided at a distance from the bond pads seen in a longitudinal direction of the connecting strips.

19. A method for assembling a semiconductor package in accordance with claim 1, wherein the method comprises the steps of: providing a semiconductor die having multiple bond pads; providing an electrically conducting clip, wherein the clip comprises, at a first side thereof, at least one pin for mounting the package to an external board and comprises, at a second side opposite to the first side, a connecting portion connecting the clip to at least two bond pads of the multiple bond pads, the connection portion comprising at least two elongated connecting strips spaced apart from each other at a distance so that each strip extends over at least one of he at least two bond pads and is connected thereto.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1a discloses a side view of a clip that is used for connecting to a bond pad of a semiconductor die in accordance with the prior art;

[0043] FIG. 1b discloses a top view of a semiconductor package having the clip shown in FIG. 1a, in accordance with the prior art;

[0044] FIG. 2a discloses a side view of a clip that is used for connecting to a bond pad of a semiconductor die, in accordance with the present disclosure;

[0045] FIG. 2b discloses a top view of a semiconductor package having the clip shown in FIG. 2a, in accordance with the present disclosure;

[0046] FIG. 3 discloses a flow chart of a method in accordance with the present disclosure.

DETAILED DESCRIPTION

[0047] It is noted that in the description of the figures, same reference numerals refer to the same or similar components performing a same or essentially similar function.

[0048] A more detailed description is made with reference to particular examples, some of which are illustrated in the appended drawings, such that the manner in which the features of the present disclosure may be understood in more detail. It is noted that the drawings only illustrate typical examples and are therefore not to be considered to limit the scope of the subject matter of the claims. The drawings are incorporated for facilitating an understanding of the disclosure and are thus not necessarily drawn to scale. Advantages of the subject matter as claimed will become apparent to those skilled in the art upon reading the description in conjunction with the accompanying drawings.

[0049] In the below, the present disclosure is being discussed with respect to a semiconductor die being either a Field Effect Transistor, FET, or a High-Electron-Mobility Transistor, HEMT. As such, three terminals are present on the semiconductor die—a gate terminal, a source terminal and a drain terminal. The gate terminal is used for providing a voltage to the semiconductor die. The semiconductor die is arranged to support a relatively large current between the drain terminal and the source terminal.

[0050] The above is one of the reasons why the semiconductor package has one pin that is connected to the gate terminal, while the semiconductor package has at least one pin for the source terminal as well as at least one pin for the drain terminal. The at least one pin may be required for supporting the relatively large current.

[0051] FIG. 1a discloses a side view of clips 101 that are used for connecting to bond pads of an semiconductor die in accordance with the prior art. FIG. 1a discloses two clips, i.e. having reference numerals 102 and 103.

[0052] The clip having reference numeral 102 is used for connecting to the source bond pad of the semiconductor die, and the clip having reference numeral 103 is used for connecting to the drain bond pad of the semiconductor die.

[0053] Reference numeral 104 shows the part of the clip that is used for mounting to the drain pad of the semiconductor die. As shown, the clip steps down from a base part, wherein the stepped down part of the clip is soldered to the drain bond pad of the semiconductor die. Reference numeral 105 shows the other end of the clip, wherein the other end is used as the pins of the semiconductor package.

[0054] Following the above, the clips 102, 103 comprise a conductive material such that they are able to conduct a current.

[0055] FIG. 1b discloses a top view 201 of a semiconductor package having the clip shown in FIG. 1a, in accordance with the prior art. The clip having reference numeral 202 is used for connecting to the drain bond pad of the semiconductor die. The clip having reference numeral 203 is used for connecting to the source bond pad of the semiconductor die. The clip having reference numeral 204 is used for connecting to the gate bond pad of the semiconductor die.

[0056] The clip 202 that is used for connecting to the drain bond pad of the semiconductor die has a first part 205 that is mounted to the drain bond pad, and has a second part 206, opposite to the first part 205, that is used as the pins of the package. The pins are used for mounting the semiconductor package to an external board, for example a Printed Circuit Board, PCB.

[0057] FIG. 2a discloses a side view of clips 301 that are used for connecting to bond pads of a semiconductor die, in accordance with the present disclosure.

[0058] The clip that is used for connecting to the drain bond pad of the semiconductor die has reference numeral 302. The clip that is used for connecting to the source bond pad of the semiconductor die has reference numeral 303. The present disclosure is elaborated with respect to the clip 302 for connecting to the drain bond pad of the semiconductor die.

[0059] The electrically conducting clip 301 comprises, at a first side thereof 305, at least one pin for mounting the package to an external board and comprises, at a second side 304 opposite to the first side 305, a connecting portion connecting said clip to at least two bond pads of said multiple bond pads.

[0060] The connection portion comprising at least two elongated connecting strips spaced apart from each other at a distance in such a manner that each strip extends over at least one of said at least two bond pads and is connected thereto. This is explained in more detail with respect to FIG. 2b.

[0061] It is noted that the clip 302 is mounted to the corresponding drain bond pad via the connection portion as indicated with reference numeral 307. The connection portion comprises multiple parallelly extending fingers. The inventors have found that it may be beneficial for connecting those fingers, at the free end thereof, to each other. One of the benefits relates to surface tension.

[0062] The above is accomplished by the bridge portion as indicated with reference numeral 306. The bridge portion 306 connects the free ends of the elongated connecting strips 307 to one another.

[0063] As shown in FIG. 2a, the bridge portion 306 is elevated with respect to the elongated connecting strips 307. This may ensure that the bridge portion 306 is noted directly connected to the respective bond pad using solder or the like. Another advantage is that this provides room for the solder fillet for connecting the strips 307 to the respective bond pads.

[0064] The bridge portion 306 is thus provided at a certain distance from said bond pads seen in a longitudinal direction of said connecting strips. The bridge portion 306 is thus not oriented above the respective bond pad, but is, from a top view, oriented next to the respective bond pad. This is shown more clearly in FIG. 2b.

[0065] FIG. 2b discloses a top view 401 of a semiconductor package having the clips shown in FIG. 2a, in accordance with the present disclosure.

[0066] Reference is made to the clip 402 that connects to the drain bond pads of the semiconductor die.

[0067] In this particular case, the semiconductor die has multiple drain pads. This is shown by the reference numeral 403. More specifically, the drain bond pads 403 are aligned in a particular row. In this particular case, five individual drain bond pads 403 are provided on the semiconductor die.

[0068] One of the aspects of the present disclosure is to provide segmented clips to fit with the segmented/individual bond pads 403. The segmented clips will have its own downsets to match up with the size of the bond pads, ensuring solderable top metal of bond pads to Cu gaps are enough to form a solder fillet. The downsets are considered as the connection portion of the clip 402.

[0069] The lead tips of the segmented clips with downsets may have an extension to overhang with respect to the drain pads, in which these extended leads may be fused together to control solder surface tension as well as the coplanarity of each drain leads downset during stamping process. This is shown by the bridge portion 405 in FIG. 2b and having reference numeral 306 in FIG. 2a.

[0070] FIG. 2b shows a uniform distance between each of the bond pads 403. Further, the connecting strips are spaced apart from each other at this particular distance in such a manner that each strip extends over its corresponding bond pad and is connected thereto. Reference numeral 404 thus indicates a cut out in the clip. The cut out itself is also elongated in shape. The cut out allows solder to flow for firmly connecting the strips to the corresponding bond pads.

[0071] Reference numeral 406 indicates the pins of the semiconductor package for mounting the semiconductor package to an external board, for example a Printed Circuit Board, PCB.

[0072] Following the above, different from the prior art situation as shown in FIGS. 1a and 1b, the bond pads are individually connected by the different strips/fingers. Further, an elevated bridge portion is provided for connecting the different strips together to mitigate and surface tension. This improves the life expectancy of the connection between the bond pad and the clip 402.

[0073] FIG. 3 discloses a flow chart of a method 501 in accordance with the present disclosure.

[0074] The method 501 is for assembling a semiconductor package in accordance with any of the previous examples, wherein said method comprises the steps of: [0075] providing 502 a semiconductor die having multiple bond pads; [0076] providing 503 an electrically conducting clip, wherein said clip comprises, at a first side thereof, at least one pin for mounting said package to an external board and comprises, at a second side opposite to said first side, a connecting portion connecting said clip to at least two bond pads of said multiple bond pads, said connection portion comprising at least two elongated connecting strips spaced apart from each other at a distance in such a manner that each strip extends over at least one of said at least two bond pads and is connected thereto. [0077] mounting 504 the electrically conducting clip on top of the semiconductor die by using, for example, a soldering process. [0078] Finally, the end of the clip is trimmed to form the pins of the semiconductor package.

[0079] The ensuing description above provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the disclosure, it being understood that various changes may be made in the function and arrangement of elements, including combinations of features from different embodiments, without departing from the scope of the disclosure.

[0080] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, electromagnetic, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0081] In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without some of these specific details.