CN101964335A - Package and method of manufacturing the same - Google Patents

Abstract

The invention discloses a package and a manufacturing method thereof. The package comprises a lead frame, a chip and a sealant. The lead frame has a notch and a plurality of first notch side lead pins, a plurality of first notch side pads, a plurality of second notch side lead pins and a plurality of second notch side pads. The first notch-side lead extends to one side of the notch, and the first notch-side bonding pad is correspondingly disposed on the first notch-side lead. The second notch-side lead extends to the other side of the notch, and the second notch-side bonding pad is correspondingly disposed on the second notch-side lead. The encapsulation covers the chip and the lead frame, and exposes the lower surface of the lead frame, and the notch exposes part of the encapsulation. According to the invention, the number of the welding pads which can be accommodated by the lead frame is increased.

Description

Package and manufacturing method thereof

technical field

The present invention relates to a package and its manufacturing method, and in particular to a package with a notch and its manufacturing method.

Background technique

With the vigorous development of the electronics industry, semiconductor packaging technology is constantly improving. Generally speaking, semiconductor packaging technology utilizes a lead frame to carry a chip, and seals the lead frame and the substrate with an encapsulant to prevent the chip from being damaged by moisture or impact. Wherein, the chip is further electrically connected to the outside through the pads of the lead frame, so as to be electrically connected to the printed circuit board.

However, under the trend of pursuing "light, thin, short, and small" in electronic products, the industry is constantly working on reducing the volume of the packaging structure to meet the trend.

Contents of the invention

The invention relates to a package and its manufacturing method, which uses the design of the lead frame to make the package more in line with the goal of "light, thin, short and small".

According to an aspect of the present invention, a package is proposed. The package includes a lead frame (LeadFrame), a chip, several conductive bumps and sealant. The lead frame has notches. The lead frame includes several first notch-side lead pins, several first notch-side welding pads, several second notch-side lead pins and several second notch-side welding pads. The first notch-side wire feet extend to one side of the notch, and the first notch-side welding pads are correspondingly arranged on the first notch-side wire feet. The second notch-side lead pins extend to the other side of the notch, and the second notch-side welding pads are correspondingly arranged on the second notch-side lead pins. The chip is arranged on the lead frame, and the chip has several pads. The conductive bump is electrically connected to the pad and the first notch-side welding pad and the second notch-side welding pad. The sealing glue covers the chip, the conductive bump and the lead frame, and exposes the lower surface of the lead frame. Wherein, the notch exposes part of the sealant.

According to another aspect of the present invention, a method for manufacturing a package is provided. The manufacturing method includes the following steps. A lead frame is provided, the lead frame has a first connection portion. The lead frame includes several first notch-side lead pins, several first notch-side welding pads, several second notch-side lead pins and several second notch-side welding pads. The first notch-side lead pins extend to one side of the first connection portion, and the first notch-side welding pads are correspondingly arranged on the first notch-side lead pins. The second notch-side lead pins extend to the other side of the first connection portion, and the second notch-side welding pads are correspondingly arranged on the second notch-side lead pins. Wherein the upper surface of each first notch-side wire foot and each second notch-side wire foot is at a distance from the upper surface of the first connection part; a chip is provided, and the chip has several pads; several conductive bumps are provided On the pad; electrically connect the pad with the first notch side pad and the second notch side pad with the conductive bump; cover the chip, the conductive bump and the lead frame with the sealant, and expose the bottom of the lead frame Surface: cut the lead frame along the extension direction of the first connection part to remove the first connection part, electrically separate the first notch side lead pin from the second notch side lead leg, and form a notch, the notch is exposed Out of the part of the sealant.

In order to make the above content of the present invention more obvious and understandable, the preferred embodiments are specifically cited below, together with the accompanying drawings, and are described in detail as follows:

Description of drawings

FIG. 1 is a flowchart of a manufacturing method of a package according to a preferred embodiment of the present invention.

FIG. 2 is a top view of the lead frame of the package of the present embodiment.

FIG. 3 is a front view of the lead frame of FIG. 2 .

FIG. 4 is a schematic diagram of the chip of this embodiment.

FIG. 5 is a schematic diagram of a chip provided with conductive bumps in this embodiment.

FIG. 6 is a schematic diagram of a leadframe provided with chips in this embodiment.

FIG. 7 is a schematic diagram illustrating another implementation manner of the lead frame of this embodiment.

FIG. 8 is an enlarged perspective view of part A in FIG. 7 .

FIG. 9 is a top view of the lead frame of FIG. 7 .

FIG. 10 is a schematic diagram of encapsulating the lead frame, chip and conductive bump in FIG. 6 with encapsulant.

FIG. 11 is a schematic diagram of a package according to a preferred embodiment of the present invention.

Explanation of reference signs

200, 256: lead frame

202: The first connecting part

204: Second connection part

206: The third connecting part

212: First notch side wire foot

214, 246: first notch side pads

216: Second notch side guide pin

218, 248: Second notch side solder pads

220: first edge side wire foot

222, 250: first edge side pads

224: second edge side conductor foot

226, 252: second edge side pads

228: chip

230: Pad

232: Conductive bump

234: Sealant

236: Lower surface of lead frame

238: Notch

240: Top surface of lead frame

242: middle position

244: Recessed Space

248: anti-oxidation metal layer

260: side surface

262: package

264: Upper surface of the lead pin on the first notch side

266: Upper surface of the lead pin on the second notch side

268: the upper surface of the first connecting part

270: Part of the sealant

272: First Side

274: Second Side

S102-S114: Steps

Detailed ways

Please refer to FIG. 1 , which shows a flowchart of a manufacturing method of a package according to a preferred embodiment of the present invention. The manufacturing method includes the following steps.

First, please refer to FIG. 2 , which shows a top view of the lead frame of the package of this embodiment. In step S102, a lead frame 200 is provided. The lead frame 200 has a first connection portion 202 and corresponding second connection portions 204 and third connection portions 206 . The first connecting portion 202 is substantially parallel to the second connecting portion 204 and the third connecting portion 206 . Moreover, the first connecting portion 202 is substantially located at a middle position 242 between the second connecting portion 204 and the third connecting portion 206 .

The lead frame 200 includes a plurality of first notch-side lead pins 212 , a plurality of first notch-side pads 214 , a plurality of second notch-side lead pins 216 and a plurality of second notch-side solder pads 218 . The first notch-side lead pin 212 extends to the first connecting portion 202 , and the first notch-side pad 214 is correspondingly disposed on the first notch-side lead pin 212 . The second notch-side lead pin 216 extends to the first connection portion 202 , and the second notch-side pad 218 is correspondingly disposed on the second notch-side lead pin 216 . Wherein, the first notch-side wire pin 212 and the second notch-side wire pin 216 are respectively located on corresponding two sides of the first connecting portion 202 .

In addition, the lead frame 200 further includes a plurality of first edge-side lead pins 220 , a plurality of first edge-side solder pads 222 , a plurality of second edge-side lead pins 224 and a plurality of second edge-side solder pads 226 . The first edge-side lead pin 220 extends to the second connection portion 204 . The first edge pad 222 is correspondingly disposed on the first edge lead pin 220 . The second edge-side lead pin 224 extends to the third connection portion 206 . The second edge pad 226 is correspondingly disposed on the second edge lead pin 224 .

The upper surface 264 of the first notch side wire pin 212, the upper surface 266 of the second notch side wire pin 216 and the upper surface 268 of the first connection part 202 are at a distance, so that the first notch side wire pin 212, the second The two notch-side lead pins 216 and the first connecting portion 202 form a concave shape, and the thickness of the first connecting portion 202 is relatively thin.

In addition, as shown in FIG. 2 , the first notch-side pads 214 and the first edge-side pads 222 are staggered, and the second notch-side pads 218 and the second edge-side pads 226 are staggered. Through the staggered arrangement of the solder pads, the space between the solder pads is fully utilized, increasing the number of solder pads that the lead frame 200 can accommodate. Preferably, but not limited, each first notch-side solder pad 214 and each second notch-side solder pad 218 extend inwardly by a first distance D1 from the second connecting portion 204 and the third connecting portion 206 respectively. Each first edge-side welding pad 222 and each second edge-side welding pad 226 extend inwardly from the second connecting portion 204 and the third connecting portion 206 for a second distance D2, wherein the first distance D1 is greater than the second distance D2. That is, the first notch-side solder pad 214, the second notch-side solder pad 218, the first edge-side solder pad 222, and the second edge-side solder pad 226 are regularly arranged, so that the solder pads that the lead frame 200 can accommodate The number of pads increases even more.

In addition, the lead frame 200 of this embodiment is a pre-plating lead frame (Pre-Plating Lead Frame, PPF). As shown in FIG. 3 , which is a front view of the lead frame of FIG. 2 , the lead frame has been pre-plated with an anti-oxidation metal layer 248 , such as Ni-Pd-Au alloy.

Next, please refer to FIG. 4 , which shows a schematic diagram of the chip of this embodiment. In step S104 , a chip 228 is provided, and the chip 228 has a plurality of pads 230 .

Next, please refer to FIG. 5 , which shows a schematic diagram of a chip provided with conductive bumps in this embodiment. In step S106 , a plurality of conductive bumps 232 are disposed on the pads 230 .

Next, please refer to FIG. 6 , which shows a schematic diagram of a leadframe provided with chips in this embodiment. In step S108, electrically connect the pad 230 with the first notch-side welding pad 214, the second notch-side welding pad 218, the first edge-side welding pad 222, and the second edge-side welding pad 226 with the conductive bump 232 .

Although the first notch-side bonding pad 214 , the second notch-side bonding pad 218 , the first edge-side bonding pad 222 and the second edge-side bonding pad 226 are formed on the lead frame 200 in the form of FIG. 6 . However, in other embodiments, the first notch-side solder pad 214 , the second notch-side solder pad 218 , the first edge-side solder pad 222 and the second edge-side solder pad 226 may also be formed on the lead frame 200 in other forms. . For example, please refer to FIG. 7 , which shows a schematic diagram of another implementation manner of the lead frame of the first embodiment. The first notch-side welding pad 246 , the second notch-side welding pad 248 , the first edge-side welding pad 250 and the second edge-side welding pad 252 of the lead frame 256 are cylindrical and protrude from the lead frame 200 . The upper surface 240 .

Please refer to FIG. 8 , which shows an enlarged perspective view of part A in FIG. 7 . The first edge pad 250 is disposed on the lead frame 200 in the form of a column, and a recessed space 244 is formed around the column, and the side surface 260 of the column is exposed from the recessed space 244 . After the conductive bump 232 (the conductive bump 232 is shown in FIG. 6 ) is disposed on the first edge side pad 250, in the subsequent reflow process (reflow), the melted conductive bump 232 and the first edge side The contact area of the pad 250 will increase. As the contact area increases, the surface tension also increases, which can enhance the bonding between the conductive bump 232 and the first edge pad 250 . In this way, the conductive bumps 232 are less likely to be dislocated, thus improving the alignment between the conductive bumps 232 and the first edge pads 250 . Similarly, when the first notch-side welding pad 246, the second notch-side welding pad 248, and the second edge-side welding pad 252 are combined with the conductive bump 232, the first edge-side welding pad will also be produced. 250 and the conductive bump 232 to enhance the effect.

In addition, please refer to FIG. 9 , which shows a top view of the lead frame in FIG. 7 . Cross-sectional shapes of the first notch-side pad 246 , the second notch-side pad 248 , the first edge-side pad 250 and the second edge-side pad 252 are circular. Although the cross-section of the cylinder in this example is illustrated as a circle, in other implementations, the cross-section of the cylinder can also be triangular, quadrangular or other shapes, and the shape is not limited by FIG. 9 .

Then, please refer to FIG. 10 , which shows a schematic diagram of encapsulating the lead frame, chip and conductive bump in FIG. 6 with encapsulant. In step S110 , the chip 228 , the conductive bump 232 and the lead frame 200 are covered with the encapsulant 234 and the lower surface 236 of the lead frame 200 is exposed.

In addition, although the lead frame 200 of this embodiment is a pre-plated lead frame. However, the lead frame 200 in FIG. 2 may not be a pre-plated lead frame. For example, if the lead frame 200 is not a pre-plated lead frame, after step S110 , an anti-oxidation metal layer (such as tin (Sn) or tin-lead (Sn—Pb) alloy) is formed on the bottom surface of the lead frame 200 . The way to form the anti-oxidation metal layer is, for example, electroplating.

Then, please also refer to FIG. 11 , which shows a schematic diagram of a package according to a preferred embodiment of the present invention. In step S112, the lead frame 200 covered by the sealant 234 is cut along the extension direction of the first connection part 202 to remove the first connection part 202, so that the lead pin 212 on the side of the first notch is connected to the side of the second notch. The lead pins 216 are electrically separated and form a notch 238 exposing a portion 270 of the encapsulant 234 .

Since the thickness of the first connecting portion 202 is relatively thin, the notch 238 can be cut out very easily. Wherein, the action of removing the first connecting portion 202 can be completed by cutting with a cutter or laser.

Since the first connecting portion 202 is substantially located in the middle of the second connecting portion 204 and the third connecting portion 206 , the positions of the notches 238 are substantially at the same position.

Then, in step S114, the lead frame 200 covered by the sealant 234 is cut along the extending direction of the second connecting portion 204 and the extending direction of the third connecting portion 206, so as to remove the second connecting portion 204 and the third connecting portion 206, and electrically separate the first edge side wire pin 220 from the second edge side wire pin 224. After the second connecting portion 204 and the third connecting portion 206 are cut off, the corresponding first side surface 272 in the package 262 is exposed. and the second side 274 . So far, the package 262 of the preferred embodiment of the present invention is completed, as shown in FIG. 11 .

The package and its manufacturing method disclosed in the above embodiments of the present invention have many advantages, and only some of the advantages are listed below:

(1) The first notch-side welding pad, the first edge-side welding pad, the second notch-side welding pad and the second edge-side welding pad are arranged in an array, which increases the number of welding pads that the lead frame can accommodate.

(2) The first notch-side welding pads and the first edge-side welding pads are arranged in a staggered manner, and the second notch-side welding pads and the second edge-side welding pads are also arranged in a staggered manner. Under the condition that the space between the welding pads is fully utilized, the number of welding pads that the lead frame can accommodate is increased.

(3) The first notch-side solder pad, the second notch-side solder pad, the first edge-side solder pad and the second edge-side solder pad are formed on the lead frame in the form of pillars. In this way, in the reflow process, the contact area between the conductive bump and the pad is increased. As the contact area increases, the surface tension also increases. Therefore, the conductive bumps are less likely to be dislocated during the reflow process.

In summary, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (10)

1. packaging part comprises:

Lead frame has recess, and this lead frame comprises:

A plurality of first notched side wiring foots extend to a side of this recess;

A plurality of first notched side weld pads are arranged on described a plurality of first notched side wiring foot accordingly;

A plurality of second notched side wiring foots extend to the opposite side of this recess; And

A plurality of second notched side weld pads are arranged on described a plurality of second notched side wiring foot accordingly;

Chip is arranged at this lead frame, and this chip has a plurality of connection pads;

A plurality of conductive projections electrically connect described a plurality of connection pad and described a plurality of first notched side weld pad and described a plurality of second notched side weld pad; And

Sealing coats this chip, described a plurality of conductive projections and this lead frame, and the lower surface of exposed this lead frame;

Wherein, this recess exposes this sealing of part.

2. packaging part as claimed in claim 1, wherein this packaging part has corresponding first side and second side, this recess between this first side and this second side and the bearing of trend of this recess be parallel to this first side and this second side in fact, this lead frame also comprises:

A plurality of first edge side wiring foots extend to this first side;

A plurality of first edge side weld pads are arranged on described a plurality of first edge side wiring foot accordingly;

A plurality of second edge side wiring foots extend to this second side; And

A plurality of second edge side weld pads are arranged on described a plurality of second edge side wiring foot accordingly;

Wherein, a plurality of conductive projections also electrically connect described a plurality of connection pad and described a plurality of first edge side weld pad and described a plurality of second edge side weld pad.

3. packaging part as claimed in claim 2, wherein said a plurality of first notched side weld pads and described a plurality of first edge side weld pad be for being staggered, and described a plurality of second notched side weld pad and described a plurality of second edge side weld pad are staggered.

4. packaging part as claimed in claim 2, wherein respectively this first notched side weld pad and respectively this second notched side weld pad respectively by this first side and this second side first distance that extends internally, this first edge side weld pad and respectively this second edge side weld pad is respectively by this first side and this second side second distance that extends internally respectively, this first distance is greater than this second distance.

5. packaging part as claimed in claim 2, the external form of wherein said a plurality of first notched side weld pads, described a plurality of second notched side weld pads, described a plurality of first edge side weld pads and described a plurality of second edge side weld pads is cylinder and this upper surface that protrudes in this lead frame.

6. the manufacture method of a packaging part comprises:

Lead frame is provided, this lead frame comprises first connecting portion, this lead frame also comprises a plurality of first notched side wiring foots, a plurality of first notched side weld pads, a plurality of second notched side wiring foots and a plurality of second notched side weld pad, described a plurality of first notched side wiring foot extends to a side of this first connecting portion, described a plurality of first notched side weld pad is arranged on a plurality of first notched side wiring foots accordingly, described a plurality of second notched side wiring foot extends to the opposite side of this first connecting portion, described a plurality of second notched side weld pad is arranged on described a plurality of second notched side wiring foot accordingly, and wherein the upper surface of the upper surface of each described a plurality of first notched side wiring foot and each described a plurality of second notched side wiring foot and this first connecting portion is at a distance of a distance;

Chip is provided, and this chip has a plurality of connection pads;

A plurality of conductive projections are set on described a plurality of connection pads;

Electrically connect described a plurality of connection pad and described a plurality of first notched side weld pad and described a plurality of second notched side weld pad with described a plurality of conductive projections;

With this chip of sealant covers, described a plurality of conductive projections and this lead frame, and the lower surface of exposed this lead frame; And

Bearing of trend along this first connecting portion cuts this lead frame, to remove this first connecting portion, described a plurality of first notched side wiring foot is electrically separated with described a plurality of second notched side wiring foots, and form a recess, and this recess exposes this sealing of part.

7. manufacture method as claimed in claim 6, wherein this lead frame also comprises:

Corresponding second connecting portion and the 3rd connecting portion, this first connecting portion is parallel to this second connecting portion and the 3rd connecting portion in fact;

A plurality of first edge side wiring foots extend to this second connecting portion;

A plurality of first edge side weld pads are arranged on described a plurality of second connecting portion edge side wiring foot accordingly;

A plurality of second edge side wiring foots extend to the 3rd connecting portion; And

A plurality of second edge side weld pads are arranged on described a plurality of second edge side wiring foot accordingly;

In this step that electrically connects with described a plurality of conductive projections, also comprise:

Electrically connect described a plurality of connection pad and described a plurality of first edge side weld pad and described a plurality of second edge side weld pad with described a plurality of conductive projections.

8. manufacture method as claimed in claim 7 also comprises:

Cut by the lead frame of this sealant covers along the bearing of trend of this second connecting portion and the bearing of trend of the 3rd connecting portion, removing this second connecting portion and the 3rd connecting portion, and described a plurality of first edge side wiring foot is electrically separated with described a plurality of second edge side wiring foots.

9. manufacture method as claimed in claim 7, the external form of wherein said a plurality of first notched side weld pads, described a plurality of second notched side weld pads, described a plurality of first edge side weld pads and described a plurality of second edge side weld pads is cylinder and the upper surface that protrudes in this lead frame.

10. manufacture method as claimed in claim 6 also comprises:

Form anti-oxidant metal layer in this lower surface of this lead frame.

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