US-20260130295-A1 - SEMICONDUCTOR PACKAGE AND A METHOD FOR FORMING THE SAME

US20260130295A1US 20260130295 A1US20260130295 A1US 20260130295A1US-20260130295-A1

Abstract

A method for forming a semiconductor package comprises: providing a molded interposer module, wherein the molded interposer module comprises an interposer having at least one central opening and a chip mounting region surrounding the at least one central opening, a plurality of semiconductor chips mounted on the chip mounting region, and a mold cap formed on the chip mounting region of the interposer to encapsulate the plurality of semiconductor chips; disposing the molded interposer module on a substrate via solder paste, wherein a flux material is formed around the solder paste, and the molded interposer module and the substrate define together a space to accommodate the solder paste, and the space has side slits that communicate with an external environment; reflowing the solder paste to form solder bumps; and spraying a deflux chemical mist towards the solder bumps through the at least one central opening and the side slits.

Inventors

Jiseon Lee
BumRyul MAENG
YeJi AHN

Assignees

STATS ChipPAC Management Pte. Ltd.

Dates

Publication Date: 20260507
Application Date: 20251102
Priority Date: 20241101

Claims (14)

1 . A method for forming a semiconductor package, comprising: providing a molded interposer module, wherein the molded interposer module comprises an interposer having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening, a plurality of semiconductor chips mounted on the chip mounting region of the interposer, and a mold cap formed on the chip mounting region of the interposer to encapsulate the plurality of semiconductor chips; disposing the molded interposer module on a substrate via solder paste, wherein a flux material is formed around the solder paste, and the molded interposer module and the substrate define together a space to accommodate the solder paste, and the space has side slits that fluidly communicate the space with an external environment; reflowing the solder paste to form a plurality of solder bumps; and spraying a deflux chemical mist towards the plurality of solder bumps through the at least one central opening of the interposer and the side slits.
2 . The method of claim 1 , wherein providing a molded interposer module comprises: mounting the plurality of semiconductor chips on the chip mounting region of the interposer; forming the mold cap on the interposer to encapsulate the plurality of semiconductor chips; attaching the mold cap onto a carrier; etching through the interposer and the mold cap to form the at least one central opening, thereby forming the molded interposer module; and removing the molded interposer module from the carrier.
3 . The method of claim 1 , disposing the molded interposer module on a substrate comprises: forming on at least one of the substrate and the molded interposer module the solder paste; forming around the solder paste the flux material; and attaching the molded interposer module onto the substrate via the plurality of solder bumps.
4 . The method of claim 1 , wherein after the step of disposing the molded interposer module on a substrate, the method further comprises: attaching additional electronic devices directly on the substrate around the molded interposer module.
5 . The method of claim 4 , wherein after the step of spraying a deflux chemical mist towards the plurality of solder bumps, the method further comprises: forming the mold on the substrate to encapsulate the molded interposer module and the additional electronic devices.
6 . The method of claim 1 , wherein after the step of spraying a deflux chemical mist towards the plurality of solder bumps, the method further comprises: filling the at least one central opening of the interposer by dispensing.
7 . A semiconductor package, comprising: a substrate; an interposer mounted on the substrate, and having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening; and a plurality of semiconductor chips mounted on the chip mounting region of the interposer.
8 . The semiconductor package of claim 7 , further comprising: a mold cap formed on the chip mounting region of the interposer to encapsulate the plurality of semiconductor chips.
9 . The semiconductor package of claim 8 , wherein the mold cap is further formed in the at least one central opening and between the plurality of semiconductor chips.
10 . The semiconductor package of claim 7 , wherein the substrate has at least one slot passing therethrough and connected with the at least one central opening.
11 . The semiconductor package of claim 7 , wherein the plurality of semiconductor chips include at least three semiconductor chips, and each of the at least one central opening is aligned with a gap between two of the plurality of semiconductor chips.
12 . The semiconductor package of claim 7 , further comprising a plurality of solder bumps disposed between the interposer and the substrate and for providing electrical connection therebetween.
13 . The semiconductor package of claim 12 , further comprising an underfill material formed between the interposer, the substrate, and each of the plurality of solder bumps.
14 . A method for forming a semiconductor package, comprising: providing an unmolded interposer module, wherein the unmolded interposer module comprises an interposer having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening, and a plurality of semiconductor chips mounted on the chip mounting region of the interposer; disposing the unmolded interposer module on a substrate via solder paste, wherein a flux material is formed around the solder paste, and the unmolded interposer module and the substrate define together a space to accommodate the solder paste, and the space has side slits that fluidly communicate the space with an external environment; reflowing the solder paste to form a plurality of solder bumps; and spraying a deflux chemical mist towards the plurality of solder bumps through the at least one central opening of the interposer and the side slits.

Description

TECHNICAL FIELD The present application generally relates to semiconductor technologies, and more particularly, to a semiconductor package and a method for forming a semiconductor package. BACKGROUND OF THE INVENTION The semiconductor industry is constantly faced with complex integration challenges as consumers want their electronics to be smaller, faster and higher performance with more and more functionalities packed into a single device. In some semiconductor packages, a Package-in-Package (PiP) or Package-on-Package (PoP) process is utilized to combine two or more integrated circuit (IC) packages together as an integrated device. The PiP or PoP devices can more efficiently use space, and reduce lengths of signal paths between the packages. In a typical PiP or PoP device, one or more pre-molded semiconductor packages or semiconductor chips may be mounted onto another semiconductor package or substrate through an interposer or other similar structures. However, it is noted that the number of semiconductor chips required to be mounted on a substrate increases significantly and the deployment of these semiconductor chips on the substrate is largely determined by a size of an interposer. However, in the case of Chip on Wafer (CoW) packages which are also called molded interposers, there are several process issues due to the large size of interposers, one of which is that after a large CoW package (e.g., 30mm*30mm or bigger) is attached on the substrate via solder bumps, deflux chemicals cannot penetrate through the CoW package, leaving flux residues between the CoW package and the substrate. The flux residues may deteriorate the performance and reliability of the devices. Therefore, a need exists for further improvement to semiconductor packages or devices with large CoW or similar large-scale components. SUMMARY OF THE INVENTION An objective of the present application is to provide a semiconductor package with improved reliability. According to an aspect of the present application, a method for forming a semiconductor package is provided. The method comprises: providing a molded interposer module, wherein the molded interposer module comprises an interposer having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening, a plurality of semiconductor chips mounted on the chip mounting region of the interposer, and a mold cap formed on the chip mounting region of the interposer to encapsulate the plurality of semiconductor chips; disposing the molded interposer module on a substrate via solder paste, wherein a flux material is formed around the solder paste, and the molded interposer module and the substrate define together a space to accommodate the solder paste, and the space has side slits that fluidly communicate the space with an external environment; reflowing the solder paste to form a plurality of solder bumps; and spraying a deflux chemical mist towards the plurality of solder bumps through the at least one central opening of interposer and the side slits. According to another aspect of the present application, a semiconductor package is disclosed. The semiconductor package comprises: a substrate; an interposer mounted on the substrate, and having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening; a plurality of semiconductor chips mounted on the chip mounting region of the interposer; and a mold cap formed on the chip mounting region of the interposer to encapsulate the plurality of semiconductor chips. According to a further aspect of the present application, a method for forming a semiconductor package is disclosed. The method comprises: providing an unmolded interposer module, wherein the unmolded interposer module comprises an interposer having at least one central opening passing therethrough and a chip mounting region surrounding the at least one central opening, and a plurality of semiconductor chips mounted on the chip mounting region of the interposer; disposing the unmolded interposer module on a substrate via solder paste, wherein a flux material is formed around the solder paste, and the unmolded interposer module and the substrate define together a space to accommodate the solder paste, and the space has side slits that fluidly communicate the space with an external environment; reflowing the solder paste to form a plurality of solder bumps; and spraying a deflux chemical mist towards the plurality of solder bumps through the at least one central opening of the interposer and the side slits. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention. Further, the accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, s