TWI384601B - Package structure and method for manufacturing the same - Google Patents

Abstract

A package structure and a method for manufacturing the same. The package structure includes a lead frame, a first chip, a plurality of conductive bumps, a second chip, a plurality of second soldering wires and a sealant. The lead frame has a plurality of first soldering pads and a plurality of second soldering pads. The first and second soldering pads are totally separated from each other. The first chip having a plurality of first conductive pads is disposed on a first surface of the lead frame. The conductive bumps are used for electrically connecting the first conductive pads and the first soldering pads. The second chip having plurality of second conductive pads is disposed on the first chip. The second soldering wires are used for electrically connecting parts of the second conductive pads and the second soldering pads. The sealant seals up the first chip, the second chip, the conductive bumps, the second soldering wires and the lead frame, and exposes a second surface of the lead frame.

Description

Package structure and manufacturing method thereof

The present invention relates to a package structure and a method of fabricating the same, and more particularly to a package structure for carrying a wafer with a lead frame and a method of fabricating the same.

With the booming electronics industry, semiconductor packaging technology continues to advance. In general, semiconductor packaging technology utilizes a substrate to carry a wafer and seals the wafer and substrate with a sealant to prevent the wafer from being wetted or damaged by collision. The electrical contacts on the wafer are further transmitted to the outside by the substrate to facilitate electrical connection with the printed circuit board.

However, in the pursuit of "light, thin, short, and small" trends in electronic products, the industry is constantly striving to reduce the size of the package structure to meet the trend.

The invention relates to a package structure and a manufacturing method thereof, which utilizes the design of the lead frame to make the package structure more suitable for the goal of “light, thin, short and small”.

According to an aspect of the invention, a package structure is proposed. The package structure comprises a lead frame, a first wafer, a plurality of conductive bumps, a second wafer, a plurality of second bonding wires and a glue. The lead frame has a plurality of first pads and a plurality of second pads. The first pads and the second pads are completely separated. The first wafer is disposed on the first surface of the lead frame, and the first wafer has a plurality of A pad. The conductive bumps are electrically connected to the first pads and the first pads. The second wafer is disposed on the first wafer. The second wafer has a plurality of second pads. The second bonding pads of the second bonding wires are electrically connected to the second pads and the second pads. The sealant seals the first wafer, the second wafer, the conductive bumps, the second bonding wires and the lead frame, and exposes the second surface of the lead frame.

According to another aspect of the present invention, a method of fabricating a package structure is presented. The semiconductor package method includes: providing a lead frame having a plurality of first pads and a plurality of second pads, wherein the first pads and the second pads are connected to each other. A first wafer is provided, the first wafer having a plurality of first pads. A plurality of conductive bumps are disposed on the first pads. The first pads and the first pads are soldered by the conductive bumps. A second wafer is disposed on the first wafer, and the second wafer has a plurality of second pads. The second pads and the second pads are soldered to the plurality of second bonding wires. The first wafer, the second wafer, the conductive bumps, the second bonding wires and the lead frame are sealed with a glue, and the second surface of the lead frame is exposed. The lead frame is cut to completely separate the first pads and the two pads.

In order to make the above-mentioned contents of the present invention more comprehensible, the preferred embodiments are described below, and the detailed description is as follows:

First embodiment

Please refer to FIG. 1 , which is a schematic diagram of a package structure 100 according to a first embodiment of the present invention. The package structure 100 includes a lead frame (Lead Frame) 130, a first wafer 110, a plurality of conductive bumps 140, a second wafer 120, a plurality of first bonding wires 150, a plurality of second bonding wires 160, and an adhesive 170. The lead frame 130 has a plurality of first pads 131 and a plurality of second pads 132. The first pad 131 and the second pad 132 are completely separated. The first wafer 110 is disposed on the first surface 130a of the lead frame 130. The first wafer 110 has a plurality of first pads 111. The conductive bumps 140 are electrically connected to the first pads 111 and the first pads 131. The second wafer 120 is disposed on the first wafer 110, and the second wafer 120 has a plurality of second pads 121. The first bonding wire 150 is electrically connected to the second pad 121 and the first pad 131. The second bonding wire 160 is electrically connected to the second pad 121 and the second pad 132. The sealant 170 seals the first wafer 110, the second wafer 120, the conductive bumps 140, the first bonding wires 150, the second bonding wires 160, and the lead frame 130, and exposes the second surface 130b of the lead frame 130.

The package structure 100 has a slot 170c formed on the lower surface of the package structure 100, and the slot 170c is located between the first pad 131 and the second pad 132. In other words, the lead frame 130 has a through slot 130c extending through the first surface 130a and the second surface 130b. The through-hole 130c is a hollow structure, and the sealant 170 covers the outside of the through-hole 130c and is not filled in the through-hole 130c. That is, the through slot 130c is a recess without the sealant 170.

Referring to FIG. 2 and FIG. 3 again, FIG. 2 is a plan view of the lead frame 130 of FIG. 1 , and FIG. 3 is a first wafer 110 , a second wafer 120 , and a conductive bump 140 of FIG . Top view of the first bonding wire 150, the second bonding wire 160 and the lead frame 130 (in the first figure, the drawing of the lead frame 130) Corresponding to the section along the section line 3-3' of Fig. 3). As shown in FIG. 2, the first pad 131 is located inside the lead frame 130 from the top view, and the second pad 132 is located on the outer side of the lead frame 130. In essence, the first pads 131 are arranged along a first rectangular frame line L1, and the second pads 132 are arranged along a second rectangular frame line L2. And the first pad 131 and the second pad 132 are staggered. As shown in FIG. 3, the first bonding wire 150 and the second bonding wire 160 are also alternately arranged. Therefore, as shown in FIG. 1, the package structure 100 is designed to pass through the first pad 131 and the second pad 132, so that the height of the first bonding wire 150 can be lower than the height of the second bonding wire 160, thereby effectively avoiding short circuit. The occurrence of the phenomenon.

Moreover, the design of the first pad 131 and the second pad 132 staggered on the inner side and the outer side of the lead frame 130 also greatly increases the number of pads that the lead frame 130 can accommodate.

Furthermore, the first wafer 110 using flip chip bonding technology and the second wafer 120 using wire bonding technology are carried and electrically connected to the same lead frame 130. As a result, the package structure 100 is more in line with the trend of "light, thin, short, and small".

Hereinafter, the manufacturing method of the package structure 100 of the present embodiment will be clearly described in a flowchart and a plurality of schematic diagrams.

Referring to FIG. 4 and FIG. 5A to FIG. 5F, FIG. 4 is a flow chart showing a manufacturing method of the package structure 100 according to the first embodiment of the present invention, and FIGS. 5A to 5F are diagrams showing the steps of the fourth embodiment. First, as shown in FIG. 5A, in step S101, the lead frame 130 is provided. The lead frame 130 of the embodiment has a plurality of first pads 131 and a plurality of second pads as described above. 132. At this time, the first pad 131 and the second pad 132 have not been separated, so the first pad 131 and the second pad 132 are still connected to each other. The lead frame 130 has a recess 133. The recess 133 is located on the second surface 130b of the lead frame 130 and between the first pad 131 and the second pad 132. The lead frame 130 of the embodiment is a copper lead frame that does not have an anti-oxidation metal layer.

Next, as shown in FIG. 5A, in step S102, the first wafer 110 is provided. The structure of the first wafer 110 is as described above and will not be repeated here.

Then, as shown in FIG. 5A, in step S103, conductive bumps 140 are disposed on the first pads 111 of the first wafer 110.

Next, as shown in FIG. 5A, in step S104, the first pads 111 and the first pads 131 are soldered by the conductive bumps 140.

Then, as shown in FIG. 5B, in step S105, the second wafer 120 is disposed on the first wafer 110. The structure of the second wafer 120 is as described above and will not be repeated here.

Next, as shown in FIG. 5C, in step S106, a portion of the second pads 121 and the first pads 131 are soldered to the first bonding wires 150.

Then, as shown in FIG. 5C, in step S107, a portion of the second pads 121 and the second pads 132 are soldered to the second bonding wires 160.

Next, as shown in FIG. 5D, in step S108, the first wafer 110, the second wafer 120, the conductive bumps 140, the first bonding wires 150, the second bonding wires 160, and the lead frame 130 are sealed with a sealant 170.

Then, as shown in FIG. 5E, in step S113, the anti-oxidation metal layer 180 (for example, tin (Sn) or tin-lead alloy (Sn-Pb)) is plated in a concave shape. The second surface 130b other than the groove 133.

Next, as shown in FIG. 5F, in step S114, the lead frame 130 is cut so that the first pad 131 and the second pad 132 are completely separated. After the cutting, the slot 170c of the package structure 100 and the through slot 130c of the lead frame 130 are simultaneously formed. Among them, this step can be cut by means of a cutter or a laser. Thus, the package structure 100 of the present embodiment is completed.

Second embodiment

Please refer to FIG. 6 and FIG. 7A to FIG. 7E. FIG. 6 is a flow chart showing a manufacturing method of the package structure 200 according to the second embodiment of the present invention, and FIGS. 7A-7E are diagrams showing the steps of FIG. The difference between the embodiment and the first embodiment is that in step S201, the lead frame 230 of the embodiment is a Pre-Plating Lead Frame (PPF Lead Frame), and the lead frame 230 is pre-plated. The oxidation resistant metal layer 280 is, for example, a nickel palladium gold alloy (Ni-Pd-Au). Therefore, as shown in FIG. 6, after step S108, step S114 can be directly performed without the step of electroplating, so that the package structure 200 of the present embodiment can be formed.

Third embodiment

Please refer to FIG. 8 and FIG. 9A to FIG. 9I. FIG. 8 is a schematic diagram showing a manufacturing method of the package structure 300 according to the third embodiment of the present invention, and FIGS. 9A-9I are schematic diagrams showing the steps of FIG. The difference between this embodiment and the first embodiment is that in step S301, the lead frame 330 of the embodiment does not have the recess 133, and is between the first pad 131 and the second pad 132. It is a flat structure. Therefore, as shown in Fig. 8, step S309, step S310, step S311, and step S312 of the present embodiment replace step S113 of the first embodiment.

First, as shown in FIG. 9A to FIG. 9D, after performing steps S301 to S108, the sealant 170 has sealed the first wafer 110, the second wafer 120, the conductive bumps 140, the first bonding wires 150, and the second bonding wires. 160 and lead frame 330, and expose the second surface 130b.

Next, as shown in FIG. 9E, in step S309, a photoresist layer 190 is formed on the second surface 130b of the lead frame 330.

Then, as shown in FIG. 9F, in step S310, the photoresist layer 190 is patterned to form an etch opening 190a, and the etch opening 190a is located between the first pad 131 and the second pad 132.

Next, as shown in FIG. 9G, in step S311, the lead frame 330 is etched by using the patterned photoresist layer 190 as a mask to form the recess 133 in the first pad 131 and the second pad 132. between.

Then, as shown in FIG. 9H, in step S312, the oxidation resistant metal layer 180 is plated on the second surface 130b other than the recess 133.

Next, as shown in FIG. 9I, in step S114, the lead frame 330 is cut so that the first pad 131 and the second pad 132 are completely separated. So far, the package structure 300 of the present embodiment has been completed.

Fourth embodiment

Referring to FIG. 10 and FIGS. 11A-11E, FIG. 10 is a flow chart showing a method of manufacturing the package structure 400 according to the fourth embodiment of the present invention. 11A to 11E are diagrams showing the steps of the tenth figure. The difference between this embodiment and the third embodiment is that in step S401, the lead frame 430 of the embodiment is a Pre-Plating Lead Frame (PPF Lead Frame). Such a lead frame 430 has been previously electroplated with an oxidation resistant metal layer 480, such as a nickel palladium gold alloy (Ni-Pd-Au). Therefore, as shown in FIG. 10, after step S108, step S414 can be directly performed without performing the electroplating step, and the package structure 400 of the present embodiment can be completed. The step S414 directly etches the lead frame 430 with the anti-oxidation metal layer 480 as a mask to completely separate the first pad 131 and the second pad 132.

Fifth embodiment

Referring to FIG. 12, a top view of a lead frame 530 of a package structure 500 according to a fifth embodiment of the present invention is shown. The difference between this embodiment and the first embodiment lies in the arrangement of the first pad 531 and the second pad 532 of the lead frame 530, and the rest of the same points are not repeated.

As shown in FIG. 12, the first pad 531 and the second pad 532 are both elongated and extend inwardly from the edge of the lead frame 530. In addition, each of the first pads 531 extends inwardly from the edge of the lead frame 530 by a first distance D1, and each of the second pads 532 extends inwardly from the edge of the lead frame 530 by a second distance D2, the first distance D1. Greater than the second distance D2. That is, the first pad 531 extends inwardly to the area inside the lead frame 530, and the second pad 532 extends only to the area outside the lead frame 530. Therefore, in the process of packaging the lead frame 530, the first pad 531 and the second pad 532 are in the sealant 170. The range (shown in Figure 14E) is in a completely separated state.

Referring to FIG. 13 and FIG. 14A to FIG. 14E, FIG. 13 is a flow chart showing a method of manufacturing the package structure 500 according to the fifth embodiment of the present invention, and FIGS. 14A to 14E are diagrams showing the steps of FIG. Here, the lead frame 530 of Figs. 14A to 14E corresponds to a cross-sectional view taken along line 13-13' of Fig. 12. As described above, the present embodiment differs from the first embodiment in the manufacturing method in the lead frame 530 provided in step S501. Since the first pad 531 and the second pad 532 of the lead frame 530 have been separated in step S501, the process can be ended after step 113, and the package structure of the embodiment can be completed without performing the step of cutting. 500.

Sixth embodiment

Referring to FIG. 15 and FIGS. 16A-16D, FIG. 15 is a flow chart showing a manufacturing method of the package structure 600 according to the sixth embodiment of the present invention, and FIGS. 16A to 16D are diagrams showing the steps of FIG. The difference between this embodiment and the fifth embodiment is that in step S601, the lead frame 630 of the embodiment is a Pre-Plating Lead Frame (PPF Lead Frame). Such lead frame 630 has been pre-plated with an oxidation resistant metal layer 680, such as a nickel palladium gold alloy (Ni-Pd-Au). Therefore, as shown in Fig. 15, after the step S108, the flow can be directly ended without performing the electroplating step, and the package structure 600 of the embodiment can be completed.

Seventh embodiment

Please refer to FIG. 17, which illustrates a package junction of a seventh embodiment of the present invention. A schematic diagram of the structure 700. The package structure 700 of the present embodiment is different from the package structure 100 of the first embodiment in the arrangement of the conductive bumps 740, and the rest of the same points are not repeated. Although the conductive bumps 140 of the first embodiment are illustrated in a ring-like arrangement, the conductive bumps 740 may also be arranged in an array. Therefore, it can be seen from the cross-section of FIG. 17 that a plurality of conductive bumps 740 are also disposed in the central region of the first wafer 110. The lead frame 730 further includes a die pad 733 which is a central portion of the lead frame 730. The peripheral conductive bumps 740 are disposed on the first pads 131, and the central conductive bumps 740 are disposed on the wafer holders 733 and electrically connected to the wafer holders 733.

The package structure and the manufacturing method thereof disclosed in the above embodiments of the present invention have a plurality of advantages. The following only some of the advantages are described as follows: first, the first pad is located inside the lead frame, and the second pad is located outside the lead frame . In essence, the first pads are arranged along a first rectangular frame line, and the second pads are arranged along a second rectangular frame line. And the first pad and the second pad are staggered, and the first bonding wire and the second bonding wire are also staggered. Therefore, the design of the package structure through the first pad and the second pad enables the height of the first bonding wire to be lower than the height of the second bonding wire, thereby effectively preventing the occurrence of a short circuit.

The second, first and second pads are staggered on the inner side and the outer side of the lead frame, and the number of pads that can be accommodated in the lead frame can also be greatly increased.

Third, the first wafer using flip chip bonding technology and bonding using wire bonding The second wafer is carried and electrically connected to the same lead frame. As a result, the package structure is more in line with the trend of “light, thin, short, and small”.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100, 200, 300, 400, 500, 600, 700‧‧‧ package structure

110‧‧‧First chip

111‧‧‧First mat

120‧‧‧second chip

121‧‧‧second mat

130, 230, 330, 430, 530, 630, 730‧‧ ‧ lead frame

130a‧‧‧ first surface

130b‧‧‧second surface

130c‧‧‧through slot

131, 531‧‧‧First pad

132, 532‧‧‧second solder pad

133‧‧‧ Groove

140, 740‧‧‧ conductive bumps

150‧‧‧First wire bond

160‧‧‧second welding line

170‧‧‧Packing

170c‧‧‧ slots

180, 280, 480, 680‧‧ ‧ anti-oxidation metal layer

190‧‧‧ photoresist layer

190a‧‧‧ etching opening

733‧‧‧ wafer holder

L1‧‧‧ first rectangular frame line

L2‧‧‧ second rectangular frame line

1 is a schematic view of a package structure according to a first embodiment of the present invention; FIG. 2 is a plan view of the lead frame of FIG. 1; and FIG. 3 is a first wafer, a second wafer, and a conductive bump of FIG. A top view of the block, the first bonding wire, the second bonding wire and the lead frame; FIG. 4 is a flow chart showing a manufacturing method of the package structure according to the first embodiment of the present invention; and FIGS. 5A-5F illustrate the steps of FIG. FIG. 6 is a flow chart showing a manufacturing method of a package structure according to a second embodiment of the present invention; FIGS. 7A to 7E are diagrams showing steps of FIG. 6; and FIG. 8 is a third embodiment of the present invention; FIG. 9A to FIG. 9I are schematic diagrams showing the steps of the eighth embodiment; and FIG. 10 is a flow chart showing the manufacturing method of the package structure according to the fourth embodiment of the present invention; 11E is a schematic view showing the steps of the 10th embodiment; FIG. 12 is a plan view showing the lead frame of the package structure according to the fifth embodiment of the present invention; and FIG. 13 is a view showing the manufacturing method of the package structure according to the fifth embodiment of the present invention. Flowchart; 14A-14E shows a schematic diagram of each step of FIG. 13; FIG. 15 shows the present invention A flowchart of a method of manufacturing a package structure of a sixth embodiment; 16A to 16D are diagrams showing the steps of the 15th figure; and FIG. 17 is a schematic view showing the package structure of the seventh embodiment of the present invention.

100‧‧‧Package structure

110‧‧‧First chip

111‧‧‧First mat

120‧‧‧second chip

121‧‧‧second mat

130‧‧‧ lead frame

130a‧‧‧ first surface

130b‧‧‧second surface

130c‧‧‧through slot

131, 531‧‧‧First pad

132, 532‧‧‧second solder pad

140‧‧‧Electrical bumps

150‧‧‧First wire bond

160‧‧‧second welding line

170‧‧‧Packing

170c‧‧‧ slots

180‧‧‧Antioxidant metal layer

Claims (18)

A package structure includes: a lead frame having a plurality of first pads and a plurality of second pads, the first pads and the second pads being completely separated; a first chip The first wafer has a plurality of first pads; the plurality of conductive bumps are electrically connected to the first pads and the first pads; a second wafer disposed on the first wafer, the second wafer having a plurality of second pads; a plurality of second bonding wires, the second pads of the electrical connection portion and the second pads; And a glue sealing the first wafer, the second wafer, the conductive bumps, the second bonding wires and the lead frame, and exposing a second surface of the lead frame; wherein the package structure further has A slot is formed in a lower surface of the package structure, the slot is located between the first pad and the second pad, and the slot is a hollow structure not filled with the sealant. The package structure of claim 1, further comprising: a plurality of first bonding wires, the second pads of the electrical connection portion, and the first pads. The package structure of claim 1, wherein the first pads are located inside the lead frame, and the second pads are located The outside of the lead frame. The package structure of claim 1, wherein the first pads and the second pads each extend inwardly from an edge of the lead frame. The package structure of claim 4, wherein each of the first pads extends inwardly from the edge of the lead frame by a first distance, each of the second pads being inwardly from an edge of the lead frame Extending a second distance, the first distance being greater than the second distance. The package structure of claim 1, wherein the first pads and the second pads are staggered. The package structure of claim 1, wherein the lead frame is a copper lead frame. The package structure of claim 1, wherein the lead frame is a Pre-Plating Lead Frame (PPF Lead Frame). The package structure of claim 1, wherein the lead frame further comprises: a die pad (Die Pad), the wafer holder being electrically connected to the first chip. A manufacturing method of a package structure includes: providing a lead frame having a plurality of first pads and a plurality of second pads, the first pads and the second pads Connected to each other; providing a first wafer, the first wafer having a plurality of first pads; a plurality of conductive bumps are disposed on the first pads; the conductive bumps are electrically connected to the first pads and the first pads; and a second wafer is disposed on the first pads, The second wafer has a plurality of second pads; the second pads and the second pads are electrically connected to the plurality of second bonding wires; the first wafer and the second are sealed with a glue a first surface of the lead frame, and the first conductive pad and the second bonding pads are separated from the second conductive surface of the lead frame and the second conductive wire and the second conductive wire. The method for manufacturing a package structure according to claim 10, further comprising: electrically connecting the plurality of first bonding wires to the second pads and the first pads. The method of manufacturing a package structure according to claim 10, wherein in the step of providing the lead frame, the lead frame has a recess, the recess being located on the second surface of the lead frame and located at the Between the first pads and the second pads. The method of manufacturing a package structure according to claim 12, wherein in the step of sealing the lead frame with the sealant, the sealant seals the groove more. The manufacturing method of the package structure according to claim 13, wherein in the step of providing the lead frame, the lead frame is a copper guide The wire rack, after the step of sealing the lead frame with the sealant, the manufacturing method of the package structure further comprises: plating an anti-oxidation metal layer on the second surface. The method of manufacturing a package structure according to claim 10, wherein in the step of providing the lead frame, the first pad and the second pad are formed in a flat structure. The manufacturing method of the package structure of claim 15, wherein after the step of sealing the lead frame with the sealant, the method of manufacturing the package structure further comprises: forming a photoresist layer on the lead frame a second surface; patterning the photoresist layer to form an etch opening between the first pad and the second pad; masking the patterned photoresist layer, etching the a lead frame to form a recess between the first pads and the second pads; and plating an anti-oxidation metal layer on the second surface. The manufacturing method of the package structure according to claim 10, wherein in the step of providing the lead frame, the lead frame is a Pre-Plating Lead Frame (PPF Lead Frame). The manufacturing method of the package structure according to claim 10, wherein the step of separating the first pads and the second pads is performed by using a cutter.