This description generally relates to semiconductor device package assemblies, such as semiconductor device package assemblies with direct leadframe to semiconductor die attachment.
Power semiconductor devices (e.g., multi-chip packages or modules) can be implemented in package apparatus (e.g., semiconductor device packages, packages, modules, multi-chip modules, etc.) that can include multiple substrates, one or more conductive spacers, multiple semiconductor die, and three or more conductive adhesive layers (e.g., solder layers), which can be arranged in a stacked configuration. Tolerance variations of these various package elements, as well as dimension tolerances of assembly process jigs (e.g., soldering jigs) used during an associated manufacturing process, can cause mechanical stress on the elements of the package, e.g., the semiconductor die and/or the substrates. Such mechanical stresses can cause quality and/or reliability issues, such as die cracking and/or substrate (e.g., ceramic) cracking (e.g., which can manifest during the assembly manufacturing process, during reliability stress testing, or as field failures).
Also, in current package implementations, controlling thicknesses of conductive adhesive layers (e.g., solder) to be sufficiently thick (e.g., to reduce thermal-mechanical stresses that can cause die cracks), but also prevent solder overflow (e.g., which can cause undesired electrical shorts in the package, and/or tilting of the semiconductor die), can be difficult. Further, in current stacked package arrangements, cost for materials used in such package can be expensive, particularly the cost of conductive spacers that are formed with materials (e.g., molybdenum copper) that are selected to reduce the incidence of die cracking during, e.g., reliability stress testing or field use.
In a general aspect, a semiconductor device package can include a substrate and a semiconductor die disposed on and coupled with the substrate. The semiconductor device package can further include a leadframe having an indentation defined therein, at least a portion of the indentation being disposed on and coupled with the semiconductor die via a conductive adhesive.
In another general aspect, a semiconductor device package can include a substrate, a first semiconductor die disposed on and coupled with the substrate and a second semiconductor die disposed on and coupled with the substrate. The semiconductor device package can also include a leadframe including: a first leadframe portion having a first indentation defined therein, a contact surface of the first indentation being disposed on and coupled with the first semiconductor die; and a second leadframe portion having a second indentation defined therein, a contact surface of the second indentation being disposed on and coupled with the second semiconductor die. The contact surface of the first indentation can be coupled with the first semiconductor die and the contact surface of the second indentation can be coupled with the second semiconductor die via a conductive adhesive.
In another general aspect, a method for producing a semiconductor device package can include coupling a semiconductor die with a substrate, and directly coupling an indentation formed in a body of a leadframe with the semiconductor die via a solder material.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
In the drawings, which may not necessarily be to scale, reference numbers for like or similar elements may not be shown for each of those elements. Also, reference numbers from one view of a given implementation may be not be repeated in the related views. Further, in some instances, for purposes of comparing different views, reference numbers from one view of a given implementation may be repeated in other views, but may not be specifically discussed with respect to each view.
This disclosure is directed to power semiconductor device package apparatus that can overcome at least some of the drawbacks of current implementations, such as those discussed above. The package apparatus described herein can be used to implement multi-chip devices, such as power semiconductor pairs (e.g., with a high-side power transistor, a low side power transistor, and associated diodes). Of course, the package apparatus described herein can be used to implement other semiconductor devices, such as discrete semiconductor devices, different multi-chip semiconductor devices, etc.
The package apparatus described herein can be implemented using direct lead attachment from a leadframe body to a semiconductor die. For instance, in such approaches, an indentation (dent, recess, depression, dip, indent, etc.) can be formed in a body (e.g., a planar body) of a leadframe. One or more contact surfaces of the indentation can be coupled (direct-lead attached) to a semiconductor die using a conductive adhesive (e.g., a solder). Such indentations can be configured, (such as in the examples described herein) to prevent shorts on a surface of a corresponding semiconductor die due to, e.g., solder overflow, when coupling the leadframe (e.g., the indentations) to the semiconductor die.
In the package apparatus described herein, a leadframe can also include a plurality of buffer legs, where the buffer legs are configured to (e.g., during attachment of the leadframe) mechanically contact the substrate and act as mechanical stops to control a respective heights of a leadframe body and an indentation with respect to a semiconductor die to which the indentation is coupled. Accordingly, a thickness of a conductive adhesive (e.g., a solder bond line thickness (BLT)) between the indentation and an associated semiconductor die can be defined as result of the buffer legs contacting (without being couple to) a substrate on which the semiconductor die is disposed. This can allow for control of an overall stack height of the substrate, the semiconductor die and the leadframe. Further, in conjunction with the indentation, the use of the buffer legs (e.g., by controlling a BLT of associated solder) can prevent electrical shorts resulting from solder overflow, and can also reduce mechanical stresses (as compared to current package apparatus) and, accordingly, prevent die cracking and/or substrate cracking.
Further, in the implementations described herein, the package apparatus exclude a conductive spacer and can include a single substrate. Accordingly, the cost of such packages (e.g., material cost, as well as manufacturing cost) can be reduced as compared to current package apparatus implementations, such as those discussed above
As shown in
In the example package 100, the planar body 133 can arranged in a first plane P1 and a contact surface of the indentation 132 (e.g., that is coupled with the semiconductor die 120) can be arranged in a second place P2. In some implementations, such as the implementation of
In this example, the leadframe 130 also includes a plurality of buffer legs 134 that are configured to contact the substrate 110 and act as mechanical stops for the leadframe 130 when it is being coupled (e.g., soldered) to the semiconductor die 120 and and/or to the substrate 110. The buffer legs 134 can be mechanically independent (e.g., not fixedly coupled to the substrate), such that the buffer legs 134 are able to move on the surface of the substrate 110 (e.g., in response to a force applied to the leadframe (e.g., to the planar body 133) by a solder jig used during a reflow process to couple the indentation 132 with the semiconductor die 120. In other words, the buffer legs 134 can control an amount of travel of the indentation 132 and the planar body 133 of the leadframe 130 along the line T when placed in a soldering jig during a solder reflow operation. Accordingly, the buffer legs can define (establish, etc.) a thickness (BLT, etc.) of the conductive adhesive (e.g., solder) 140 used to couple the indentation 132 with the semiconductor die 120.
Referring to
Referring to
As further shown in
In this example implementation, the first tab of the indentation 132 can also include a sloped portion 132c that is disposed between the planar body 133 of the leadframe and the contact surface 132a. The sloped portion 132c can be described as being sloped with respect to the first plane P1, and with respect to the second plane P2. Likewise, the second tab of the indentation 132 can also include a sloped portion 132d that is disposed between the planar body 133 of the leadframe and the contact surface 132b. As with the sloped portion 132c, the sloped portion 132d can be described as being sloped with respect to the first plane P1, and with respect to the second plane P2. As also shown in
Referring to
Referring to
The substrate assembly 410 can further include landing pads 460, where the landing pads are isolated (electrically isolated) portions of the patterned metal layer of the substrate assembly 410, and can be used as landing pads for buffer feet of the leadframe 430 of
Referring to
As shown in
The leadframe 430, in this example implementation, can include signal leads 480 that can be direct-lead attached to the substrate assembly 410 and provide electrical connections to the semiconductor die 420a and 420c through the wire bonds 470. The leadframe 430, in this example implementation, can further include an output terminal 490a, a negative (e.g., ground) power supply terminal 490b and a positive (e.g., Vdd) power supply terminal 490c.
In this example implementation, in the assembly 400 shown in
Referring to
Referring to
As shown in
At block 540, wire bonds (e.g., such as the wire bonds 470 shown in
At block 550 of the method 500, a solder dotting or solder printing operation can be performed on the semiconductor die 120 (e.g., conductive adhesive 140) and/or the substrate 110 to define where electrical connections between the leadframe 130 and the semiconductor die 120, and/or electrical connections between the leadframe 130 and the substrate 120 will be defined. For instance, solder dotting for connection of the indentation 132 with the semiconductor die 120, for connection of signal leads with the substrate 110, etc. can be performed at block 550. At block 560, the leadframe 130 can be mounted on the semiconductor die 120 and the substrate 110 (e.g., using a soldering jig). Further at block 560, a bond line thickness of the conductive adhesive (solder) 140 can be controlled by the buffer legs 134 of the leadframe acting as mechanical stops against the substrate 110, such as described herein.
At block 560, the method 500 can include performing another solder reflow operation to couple (solder) the leadframe 130 (via the indentation 132) to the semiconductor die 120, and/or couple (solder) the leadframe 130 (e.g., the signal leads 480) to the substrate 110. It is noted that, as was discussed above, in the example implementations described herein, the buffer legs 134 are not soldered to (remain mechanically independent from) the substrate 110, such that the buffer legs 134 can move with respect to the substrate (e.g., move on the landing pads 460 shown in
It will be understood that, in the foregoing description, when an element is referred to as being on, connected to, electrically connected to, coupled to, or electrically coupled to another element, it may be directly on, connected or coupled to the other element, or one or more intervening elements may be present. In contrast, when an element is referred to as being directly on, directly connected to or directly coupled to another element, there are no intervening elements present. Although the terms directly on, directly connected to, or directly coupled to may not be used throughout the detailed description, elements that are shown as being directly on, directly connected or directly coupled can be referred to as such. The claims of the application, if any, may be amended to recite exemplary relationships described in the specification or shown in the figures.
As used in this specification, a singular form may, unless definitely indicating a particular case in terms of the context, include a plural form. Spatially relative terms (e.g., over, above, upper, under, beneath, below, lower, and so forth) are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. In some implementations, the relative terms above and below can, respectively, include vertically above and vertically below. In some implementations, the term adjacent can include laterally adjacent to or horizontally adjacent to.
Implementations of the various techniques described herein may be implemented in (e.g., included in) digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Some implementations may be implemented using various semiconductor processing and/or packaging techniques. Some implementations may be implemented using various types of semiconductor processing techniques associated with semiconductor substrates including, but not limited to, for example, Silicon (Si), Gallium Arsenide (GaAs), Gallium Nitride (GaN), Silicon Carbide (SiC) and/or so forth.
While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the scope of the implementations. It should be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The implementations described herein can include various combinations and/or sub-combinations of the functions, components and/or features of the different implementations described.
Number | Name | Date | Kind |
---|---|---|---|
4827376 | Voss | May 1989 | A |
5250843 | Eichelberger | Oct 1993 | A |
5612259 | Okutomo | Mar 1997 | A |
5673479 | Hawthorne | Oct 1997 | A |
5896651 | Hawthorne | Apr 1999 | A |
5969413 | Yano | Oct 1999 | A |
6630726 | Crowley | Oct 2003 | B1 |
6849930 | Nakajima | Feb 2005 | B2 |
8072047 | Camacho | Dec 2011 | B2 |
8084299 | Tan | Dec 2011 | B2 |
10199303 | Sanchez | Feb 2019 | B1 |
20040157372 | Manatad | Aug 2004 | A1 |
20050067676 | Mahadevan | Mar 2005 | A1 |
20070090502 | Zhao | Apr 2007 | A1 |
20070200210 | Zhao | Aug 2007 | A1 |
20070246808 | Ewe | Oct 2007 | A1 |
20070262346 | Otremba | Nov 2007 | A1 |
20090039485 | Lee | Feb 2009 | A1 |
20090102031 | Almagro | Apr 2009 | A1 |
20090250795 | Hooper | Oct 2009 | A1 |
20090250796 | Tsui | Oct 2009 | A1 |
20110081750 | Machida | Apr 2011 | A1 |
20110095409 | Xue | Apr 2011 | A1 |
20120181676 | Tsui | Jul 2012 | A1 |
20120280408 | Do | Nov 2012 | A1 |
20130009299 | Takada | Jan 2013 | A1 |
20130093072 | Zhang | Apr 2013 | A1 |
20130161670 | Peng | Jun 2013 | A1 |
20140353818 | Geitner et al. | Dec 2014 | A1 |
20160307826 | McKnight-MacNeil | Oct 2016 | A1 |
20160343590 | Yoshihara | Nov 2016 | A1 |
20160358843 | Arokiasamy | Dec 2016 | A1 |
20170033055 | Watanabe | Feb 2017 | A1 |
20170317036 | Myers | Nov 2017 | A1 |
20180122725 | Im | May 2018 | A1 |
20190129873 | Zhao | May 2019 | A1 |
20190259688 | Scharf | Aug 2019 | A1 |
20200350238 | Hong | Nov 2020 | A1 |
20210013136 | Cho | Jan 2021 | A1 |
20210035891 | Lam | Feb 2021 | A1 |
20210217679 | Cheng | Jul 2021 | A1 |
Number | Date | Country |
---|---|---|
2080690 | Oct 2016 | CA |
101158737 | Apr 2008 | CN |
103674399 | Mar 2014 | CN |
108155157 | Jun 2018 | CN |
102009030325 | May 2014 | DE |
H10504137 | Apr 1998 | JP |
2005085897 | Mar 2005 | JP |
20130013075 | Feb 2013 | KR |
20170008023 | Jan 2017 | KR |
2475885 | Feb 2013 | RU |
2006000180 | Jan 2006 | WO |
2013075108 | May 2013 | WO |
2018207856 | Nov 2018 | WO |
Number | Date | Country | |
---|---|---|---|
20210143107 A1 | May 2021 | US |