CN201766073U - Lead frame and its packaging structure that can strengthen the bonding degree of sealing glue - Google Patents

Abstract

The utility model relates to a lead frame and a packaging structure capable of strengthening the joint degree of sealing glue, wherein the lead frame capable of strengthening the joint degree of sealing glue comprises a chip seat and a foot connecting frame. The chip holder comprises a chip bearing platform and a base. The chip bearing platform comprises a side protrusion protruding out of the base, the lower surface of the side protrusion intersects with the side wall of the base in an inner line, the lower surface is provided with a groove in an upward concave manner, and the groove is adjacent to and extends along at least one part of the inner line. Furthermore, the pin frame comprises a pin platform and a bottom frame. The pin platform comprises a flange part which protrudes out of the chassis, the lower surface of the flange part is intersected with the side wall of the chassis in a wiring, a groove is arranged on the lower surface in an upward concave mode, and the groove is adjacent to and extends along at least one part of the wiring. Therefore, the utility model discloses can improve the lead frame by a wide margin and glue the joint strength who seals, reduce the condition of sealing the gluey delaminating.

Description

Lead frame and its packaging structure that can strengthen the bonding degree of sealing glue

technical field

The utility model relates to a lead frame and its packaging structure capable of strengthening the bonding degree of sealing glue, in particular to a lead frame and its packaging structure suitable for strengthening the joint strength of the sealing glue layer and the lead frame.

Background technique

Please refer to FIG. 1 . FIG. 1 is a schematic cross-sectional view of a known semiconductor package. As shown in the figure, a semiconductor chip 91 is fixed on a known lead frame 9 and electrically connected with gold wires 92 . Furthermore, the semiconductor chip 91 , the gold wire 92 , and the known lead frame 9 are covered by the sealant 93 to achieve the functions of protection and insulation. However, with the continuous development of science and technology, electronic components are also rapidly developing towards the trend of being lighter, thinner, shorter and smaller. Therefore, in response to the trend of shrinking electronic components, the size of the lead frame 9 is also shrinking, and the contact area between the lead frame 9 and the sealant 93 is gradually limited.

Accordingly, since it is known that the contact portion between the lead frame 9 and the sealant 93 is smooth, and the contact area decreases sharply due to the trend, the strength of the joint is greatly reduced, thereby increasing the delamination of the lead frame 9 and the sealant 93. ) phenomenon, and even cause the guide pin to fall off after Singulation, seriously affecting the process yield. In particular, the QFN (Quad Flat Non-lead) package has gradually become the mainstream of the packaging process. The QFN package is characterized in that it is not provided with external leads, that is, it is not formed as in the known quadrilateral planar (QFP) semiconductor package. An external pin that is electrically connected to the outside world. In this way, the QFN package can reduce the size of the semiconductor package, but the delamination of the lead frame and the sealant is also becoming more serious.

Please refer to FIG. 2 , which is a schematic cross-sectional view of another known semiconductor package. Furthermore, with the continuous improvement of technology, there is a T-shaped or inverted L-shaped known lead frame 94, which is characterized in that the T-shaped or inverted L-shaped protruding platform 95 can be used to increase the contact between the lead frame 94 and the package. Glue 96 joint strength. However, although this method can enhance the joint strength, it is still insufficient, and delamination is still easy to occur.

Utility model content

The utility model relates to a lead frame capable of strengthening the bonding degree of sealing glue, comprising: a chip seat and a tripod. Wherein, the chip seat includes a chip carrying platform and a base. The chip carrying platform includes a side convex portion, which protrudes out of the base, the side convex portion includes a lower surface, the base includes a side wall, and the lower surface and the side wall intersect on an inner line, and the lower surface is concavely provided with a groove. The groove is adjacent to the inner wire, and the groove extends along at least a part of the inner wire.

Furthermore, the stand includes a stand and a bottom frame. Wherein, the foot platform includes a flange portion protruding out of the bottom frame, the flange portion includes a lower surface, and the bottom frame includes a side wall. The lower surface intersects with the side wall at a line, and a concave groove is formed on the lower surface. The groove is adjacent to the wiring, and the groove extends along at least a part of the wiring. Therefore, the utility model can greatly increase the contact area between the lead frame and the sealant by setting the side protrusions, flanges, grooves and grooves, thereby significantly improving the joint strength and reducing the delamination of the sealant.

Wherein, the grooves and grooves of the lead frame which can strengthen the joint degree of the sealant of the present invention can have the same depth, of course, they can also have different depths. In addition, the depths of the grooves and grooves of the present invention can be controlled by technological conditions, and thus the gripping force of the joint between the lead frame and the sealant can be further adjusted to achieve the best holding force. Furthermore, at least one metal pin is arranged on the pin platform of the pin frame of the lead frame which can strengthen the adhesive bonding degree of the present invention, which is used for electrically connecting the chip.

In addition, in the utility model, the groove and groove of the lead frame which can strengthen the joint degree of sealing glue can be an arc-shaped groove respectively, and the arc-shaped groove can be a half-arc groove. However, the arc-shaped groove of the present invention is not limited to a semi-circular arc, and it can also be a quarter-divided three-arc groove, an elliptical arc groove, or other arc shapes. In addition, the groove and groove of the present invention can also be a polygonal groove, such as a trapezoidal groove, a triangular groove, a rectangular groove, a tapered groove, or other equivalent polygonal grooves.

Another aspect of the present invention is a packaging structure capable of strengthening the bonding degree of sealing glue, including: a lead frame, a chip, at least one bonding wire, and sealing glue. Wherein, the lead frame includes a chip seat and a socket frame. And the chip seat includes a chip carrying platform and a base. The chip carrying platform includes a lower surface, the base includes a side wall, and the lower surface and the side wall intersect on an inner line, and a groove is recessed on the lower surface. Wherein, the groove is adjacent to the inner wire, and the groove extends along at least a part of the inner wire.

As for, the socket frame of the present utility model includes a socket platform and a bottom frame. The pin table includes a lower surface, the bottom frame includes a side wall, and the lower surface and the side wall intersect at a wiring. A groove is recessed on the lower surface, and the groove is adjacent to the wiring, and the groove extends along at least a part of the wiring. Furthermore, at least one metal pin is arranged on the pin platform of the pin frame.

Moreover, the chip of the present invention is fixed on the chip carrying platform, and the upper surface of the chip includes at least one welding pad. In addition, the at least one bonding wire of the present invention is to electrically connect at least one bonding pad of the chip and at least one metal pin of the stand. However, the encapsulant of the present invention covers the part of the chip, at least one bonding wire, and the lead frame, and fills the grooves and grooves. Accordingly, the utility model increases the bonding strength between the lead frame and the sealant through the side protrusions, flanges, grooves, and grooves.

In addition, the chip of the present invention can be fixed on the chip carrier corresponding to the base, and does not protrude out of the side wall of the base. This is mainly because the chip carrier below needs to bear greater bearing stress. Accordingly, the chip of the present invention preferably does not protrude out of the side wall of the base, and is not located directly above the groove. In this way, it is possible to avoid bending or breaking of the lower side protrusions or grooves due to excessive bearing stress. In addition, the at least one bonding wire of the present invention is electrically connected to at least one bonding pad of the chip and the at least one metal pin on the bottom frame, and is preferably not directly above the groove. Likewise, in order to avoid excessive bearing stress during the wire bonding process, the flanges will be bent or broken.

The beneficial effect of the utility model is that the bonding strength between the lead frame and the sealant can be greatly improved, and the delamination of the sealant can be reduced.

Description of drawings

In order to enable the examiner to further understand and understand the purpose, technical features and effects of the utility model, the detailed description is as follows in conjunction with the embodiments and accompanying drawings, among which:

FIG. 1A is a schematic cross-sectional view of a known semiconductor package.

FIG. 1B is a schematic cross-sectional view of another known semiconductor package.

Fig. 2 is a top view of the first embodiment of the utility model.

Fig. 3A is a cross-sectional view of the first embodiment of the present invention.

Fig. 3B is a partially enlarged view of the cross-sectional view of the first embodiment of the present invention.

Fig. 4 is a cross-sectional view of the second embodiment of the present invention.

Fig. 5 is a sectional view of the third embodiment of the present invention.

Fig. 6 is a sectional view of the fourth embodiment of the present utility model.

Fig. 7 is a sectional view of the fifth embodiment of the present utility model.

Fig. 8 is a sectional view of the sixth embodiment of the present utility model.

Detailed ways

Please refer to FIG. 2, FIG. 3A, and FIG. 3B at the same time. FIG. 2 is a top view of the first embodiment of the packaging structure of the utility model that can strengthen the bonding degree of sealing glue, and FIG. 3A is a cross-sectional view of the packaging structure of the first embodiment of the utility model. , FIG. 3B is a partial enlarged view of the cross-sectional view of the package structure of the first embodiment of the present invention. The figure mainly shows a lead frame 1, a chip 4, a plurality of bonding wires 5, and a sealing colloid 6.

Wherein, the lead frame 1 includes a chip holder 2 and a socket frame 3 . The chip holder 2 includes a chip carrier 21 and a base 22. The chip carrier 21 is integrally connected to the top of the base 22, and has a side protrusion 210 outside the side wall 221 of the side protruding from the base 22, and the side protrudes. The portion 210 further includes a lower surface 211 . In addition, the lower surface 211 and the side wall 221 intersect on an inner line 24 , that is, the lower surface 211 and the side wall 221 are connected to the inner line 24 . In addition, a groove 23 is recessed upward on the lower surface 211 , which is adjacent to the inner wire 24 , and the groove 23 extends along the inner wire 24 .

Furthermore, the figure also shows a socket frame 3 , which includes a socket platform 31 and a bottom frame 32 . The pin platform 31 includes a lower surface 311 , and the bottom frame 32 includes a side wall 321 . Similarly, the pin platform 31 is integrally connected to the bottom frame 32 and has a flange portion 310 protruding from the side wall 321 of the bottom frame 32 . In addition, the lower surface 311 of the flange portion 310 intersects with the side wall 321 of the bottom frame 32 at a wire 37 , that is, the lower surface 311 and the side wall 321 are connected to the wire 37 . In addition, a groove 33 is recessed on the lower surface 311 , which is adjacent to the wire 37 , and the groove 33 is along the wire 37 . Moreover, a metal pin 34 is arranged on the pin platform 31 of the pin frame 3 in this embodiment, which is usually made of silver or lead, and is completely plated on the upper surface of the pin platform 31 .

In this embodiment, the groove 23 and the groove 33 are formed by etching, and both have a depth D. As shown in FIG. Accordingly, the depth can be controlled by setting the process conditions, and thus the gripping force can be further adjusted to achieve the best holding force. Furthermore, the groove 23 and the groove 33 in this embodiment extend along the entire inner wire 24 and the connection 37 respectively. However, the groove 23 and the groove 33 can also adopt laser technology or other equivalent processes, so the groove 23 and the groove 33 can also be segmented along at least a part of the inner line 24 and the wiring 37 respectively. Extend for deployment. Moreover, in this embodiment, the groove 23 and the groove 33 are respectively an arc groove 20 and a semicircular groove 30 .

In addition, another chip 4 is shown in the figure, which is fixed on the chip carrier 21 of the chip holder 2 , and the upper surface 41 of the chip 4 includes a plurality of welding pads 411 . In this embodiment, the chip 4 is fixed on the chip carrier 21 corresponding to the base 22 , and does not protrude out of the sidewall 221 of the base 22 and is not directly above the groove 23 . The main reason is that when the chip 4 is in the die-bonding process, the chip carrier 21 below needs to bear a relatively large load-bearing stress. Such an arrangement will prevent the lower side protrusion 210 or the groove 23 from being subjected to excessive load-bearing stress, resulting in bent or broken.

Moreover, the figure shows a plurality of bonding wires 5 , which are respectively electrically connected to the plurality of bonding pads 411 of the chip 4 and the metal pins 34 of the standoff 3 . Among them, the plurality of bonding wires 5 in this embodiment are respectively electrically connected to the bonding pads 411 of the chip 4 and the metal pins 34 on the bottom frame 32, and are not located directly above the groove 33. . Similarly, in order to avoid excessive wire bonding stress during the wire bonding process, resulting in bending or breaking of the flange 310 or the groove 33 .

Furthermore, the encapsulant 6 covers the chip 4 , at least one bonding wire 5 , and parts of the lead frame 1 and fills the groove 23 and the groove 33 . Therefore, the arrangement of the side protrusion 210, the flange 310, the groove 23, and the concave groove 33 in the present invention not only increases the joint area between the lead frame 1 and the sealant 6, but also makes use of the clamping characteristics of the structure, so as to be able to The bonding strength between the lead frame 1 and the sealant 6 is greatly improved, and the delamination of the sealant 6 from any direction is avoided, thereby improving the yield rate and greatly reducing the cost.

Please refer to FIG. 4 . FIG. 4 is a cross-sectional view of a second embodiment of the packaging structure of the present invention that can strengthen the bonding degree of sealing glue. The main difference between the second embodiment and the first embodiment is that the groove 23 and the groove 33 of the first embodiment are respectively semi-arc grooves 30 and the whole is located on the lower surface 211 of the chip carrier 21 and the contact surface respectively. The lower surface 311 of the foot platform 31 . On the other hand, the groove 23 and the groove 33 of the second embodiment are all quartered three-arc grooves 36, and they are respectively located on the lower surface 211 of the chip carrier 21, the side wall 221 of the base 22, and the contact surface. The lower surface 311 of the foot platform 31 is on the side wall 321 of the bottom frame 32 .

Please refer to Fig. 5, Fig. 6, Fig. 7, and Fig. 8 at the same time. Fig. 5 is a cross-sectional view of the third embodiment of the packaging structure of the utility model that can strengthen the joint degree of sealing glue, and Fig. 6 is the package of the fourth embodiment of the utility model. The cross-sectional view of the structure, Fig. 7 is a cross-sectional view of the packaging structure of the fifth embodiment of the present invention, and Fig. 8 is a cross-sectional view of the sixth embodiment of the present invention. The main difference between the third embodiment shown in FIG. 5 and the above-mentioned embodiments is that the groove 23 and the groove 33 of the third embodiment are respectively a polygonal groove 35 and a trapezoidal groove 351 . In addition, the groove 23 and the groove 33 of the fourth embodiment shown in FIG. 6 are also a polygonal groove 35 , but they are a triangular groove 352 . As for the fifth embodiment shown in FIG. 7, the groove 23 and the groove 33 are also polygonal grooves 35 and rectangular grooves 353 respectively, and they are respectively located on the lower surface 211 and the base of the chip carrier 21. 22 on the side wall 221 , and the lower surface 311 of the pin platform 31 and the side wall 321 of the chassis 32 . In addition, in the sixth embodiment shown in FIG. 8 , the groove 23 and the groove 33 are also polygonal grooves 35 and irregular polygonal grooves 354 respectively, mainly to illustrate that the present invention can be applied to any shape. Groove 23, or groove 33.

Claims (12)

1. the lead frame that can strengthen the sealing conjugation grade is characterized in that, comprising:

One chip carrier, include a chip bearing platform, reach a base, this chip bearing platform includes a side protuberance, it is to protrude out outside this base, and this side protuberance includes a lower surface, and this base includes a sidewall, this lower surface and this sidewall intersect at interior lines, this lower surface of this chip bearing platform upwards is concaved with a groove, and this groove is adjacent to this interior lines, and this groove extends along at least one part of these interior lines; And

One pin frame, include a pin platform, reach a underframe, this pin platform includes a flange part, it protrudes out outside this underframe, and this flange part includes a lower surface, and this underframe includes a sidewall, this lower surface and this sidewall intersect at a wiring, this lower surface of this pin platform upwards is concaved with a chase, and this chase is adjacent to this wiring, and this chase extends along at least one part of this wiring.

2. the lead frame of strengthening the sealing conjugation grade as claimed in claim 1 is characterized in that, wherein, this groove, and this chase have same depth.

3. the lead frame of strengthening the sealing conjugation grade as claimed in claim 1 is characterized in that, wherein, this groove, and this chase be respectively an arcuate furrow.

4. the lead frame of strengthening the sealing conjugation grade as claimed in claim 3 is characterized in that, wherein, this arcuate furrow is half arc groove.

5. the lead frame of strengthening the sealing conjugation grade as claimed in claim 1 is characterized in that, wherein, this groove, and this chase be respectively a polygon groove.

6. the lead frame of strengthening the sealing conjugation grade as claimed in claim 5 is characterized in that, wherein, this polygon groove is a trapezoidal groove.

7. the lead frame of strengthening the sealing conjugation grade as claimed in claim 1 is characterized in that, wherein, is laid with at least one metal pin on this pin platform of this pin frame.

8. the encapsulating structure that can strengthen the sealing conjugation grade is characterized in that, comprising:

One lead frame, comprise a chip carrier, reach a pin frame, this chip carrier includes a chip bearing platform, reaches a base, and this chip bearing platform includes a side protuberance, and it protrudes out outside this base, this side protuberance includes a lower surface, this base includes a sidewall, and this lower surface of this chip bearing platform and this sidewall of this base intersect at interior lines, and this lower surface of this chip bearing platform upwards is concaved with a groove, this groove is adjacent to this interior lines, and this groove extends along at least one part of these interior lines; This pin frame includes a pin platform, reaches a underframe, this pin platform includes a flange part, it protrudes out outside this underframe, this flange part includes a lower surface, and this underframe includes a sidewall, and this lower surface of this pin platform and this sidewall of this underframe intersect at a wiring, this lower surface upwards is concaved with a chase, this chase is adjacent to this wiring, and this chase extends along at least one part of this wiring, is laid with at least one metal pin on this pin platform of this pin frame;

One chip is fixedly arranged on this chip bearing platform, and the upper surface of this chip includes at least one weld pad;

At least one bonding wire electrically connects this at least one weld pad of this chip and this at least one metal pin of this pin frame; And

One adhesive body coats this chip, this at least one bonding wire, reaches the part of this lead frame and fills up this groove, reaches this chase.

9. the encapsulating structure of strengthening the sealing conjugation grade as claimed in claim 8 is characterized in that, wherein, this groove, and this chase be respectively an arcuate furrow.

10. the encapsulating structure of strengthening the sealing conjugation grade as claimed in claim 8 is characterized in that, wherein, this groove, and this chase be respectively a polygon groove.

11. the encapsulating structure of strengthening the sealing conjugation grade as claimed in claim 8 is characterized in that, this chip is to be fixedly arranged on this chip bearing platform and corresponding to this base position.

12. the encapsulating structure of strengthening the sealing conjugation grade as claimed in claim 8 is characterized in that, this at least one bonding wire electrically connects this at least one weld pad of this chip and this pin chord position on this at least one metal pin of this underframe top.

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