Chipmos Technologies Inc.

Chipmos Technologies (bermuda) Ltd

Hung-Tsun Lin

Wu-Chang Tu

Cheng-Ting Wu

A BGA package primarily includes a leadless leadframe with a plurality of leads, a chip disposed on the leads, a die-attaching layer adhering to an active surface of the chip and the top surfaces of the leads, a plurality of bonding wires electrically connecting the chip to the leads, an encapsulant, and a plurality of solder balls. Each lead has a bottom surface including a wire-bonding area and a ball-placement area, moreover, a plurality of lips project from the bottom surfaces of the leads around the ball-placement areas. The encapsulant encapsulates the chip, the bonding wires, the die-attaching layer, and the top surfaces, the bottom surfaces except the ball-placement areas. The solder balls are disposed on the ball-placement areas.

BGA package with leads on chip

A leadless semiconductor package with an electroplated layer embedded in an encapsulant and its manufacturing processes are disclosed. The package primarily includes a half-etched leadframe, a chip, an encapsulant, and an electroplated layer. The half-etched leadframe has a plurality of leads and a plurality of outer pads integrally connected to the leads. The encapsulant encapsulates the chip and the leads and has a plurality of cavities reaching to the outer pads to form an electroplated layer on the outer pads and embedded in the cavities. Accordingly, under the advantages of lower cost and higher thermal dissipation, the conventional substrates and their solder masks for BGA (Ball Grid Array) or LGA (Land Grid Array) packages can be replaced. The leads encapsulated in the encapsulant have a better bonding strength and the electroplated layer embedded in the encapsulant will not be damaged during shipping, handling, or storing the semiconductor packages. Furthermore, the manufacturing processes include two half-etching steps to form the half-etched leadframe where a second half-etching step is performed after forming the encapsulant and before forming the electroplated layer.

Leadless semiconductor package with electroplated layer embedded in encapsulant and the method for manufacturing the same

An IC package primarily comprises a substrate, a die-attaching layer, a chip, at least a bonding wire, and a plurality of electrical connecting components. The substrate has a top surface and a bottom surface where the top surface includes a die-attaching area for disposing the die-attaching layer. The chip is attached to the die-attaching area by the die-attaching layer and is electrically connected to the substrate by the electrical connecting components. Both ends of the bonding wire are bonded to two interconnecting fingers on the top surface of the substrate where at least a portion of the bonding wire is encapsulated in the die-attaching layer to replace some wirings or vias inside a conventional substrate. Therefore, the substrate has simple and reduced wiring layers, i.e., to reduce the substrate cost. A chip carrier of the corresponding IC package is also revealed.

IC package reducing wiring layers on substrate and its chip carrier

A manufacturing process of a leadframe-based BGA package is disclosed. A leadless leadframe with an upper layer and a lower layer is provided for the package. The upper layer includes a plurality of ball pads, and the lower layer includes a plurality of sacrificial pads aligning and connecting with the ball pads. A plurality of leads are formed in either the upper layer or the lower layer to interconnect the ball pads or the sacrificial pads. An encapsulant is formed to embed the ball pads after chip attachment and electrical connections. During manufacturing process, a half-etching process is performed after encapsulation to remove the sacrificial pads to make the ball pads electrically isolated and exposed from the encapsulant for solder ball placement where the soldering areas of the ball pads are defined without the need of solder mask(s) to solve the problem of solder bleeding of the solder balls on the leads or the undesired spots during reflow. Moreover, mold flash can easily be detected and removed.

Manufacturing process of leadframe-based BGA packages

A leadless leadframe has a plurality of bottom leads and a plurality of top soldering pads formed in different layers. After encapsulation and before solder ball placement, a half-etching process is performed to remove the bottom leads to make the top soldering pads electrically isolated, exposed and embedded in the encapsulant for solder ball placement where the soldering area of the top soldering pads is defined without the need of solder mask(s) to solve the diffusion of solder balls on the leads during reflow.

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Tainan, Taiwan

Hung-Tsun Lin