CN213366590U

CN213366590U - 28-pin integrated circuit lead frame

Info

Publication number: CN213366590U
Application number: CN202022374217.2U
Authority: CN
Inventors: 潘龙慧; 冯军民; 江焕辉
Original assignee: Ningbo Dezhou Precision Electronic Co ltd
Current assignee: Ningbo Dezhou Precision Electronic Co ltd
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2021-06-04
Anticipated expiration: 2030-10-22

Abstract

The utility model discloses a 28 pin integrated circuit lead frame, including a plurality of repetitive arrangement's lead frame unit, the lead frame unit includes the base island, and characteristics are: the base island distributes all around has twenty eight pins, and the interior tip of every pin all is provided with the solder joint, and the outer end of pin extends to the horizontal both sides of base island, connects through first splice bar between the outer end of same one side every pin, just lies in on every pin and all has seted up the incision in advance between solder joint and the splice bar, and the incision in advance all lies in the symmetrical groove of precutting of both sides formation that makes the base island on same water flat line, and the advantage is: the 28-pin integrated circuit lead frame is strong in glue locking capacity and more stable in package performance.

Description

28-pin integrated circuit lead frame

Technical Field

The utility model relates to an integrated circuit technical field especially relates to a 28 pin integrated circuit lead frame.

Background

The lead frame of the integrated circuit is used as a chip carrier of the integrated circuit, is a key structural member for realizing the electrical connection between the leading-out end of the internal circuit of the chip and an external lead by means of bonding materials to form an electrical circuit, plays a role of a bridge connected with an external lead, needs to use the lead frame in most semiconductor integrated blocks, and is an important basic material in the electronic information industry. The volume, the conductivity, the heat dissipation performance and the like of the lead frame can affect the performance of the packaged power device.

With the increase of packaging density, the packaging volume is reduced, the lead density is rapidly increased, and the market demands for lead frames are developing towards the directions of high precision, multiple pins and small spacing. The larger the number of leads of the lead frame, the higher the density and the stronger the functionality. In the existing 28-pin lead frame in the chip packaging process, because the lead frame has a large number of pins and high density, the high-temperature molten powdery colloid is not easily fixed with the pins of the lead frame in the manufacturing process, and is easy to vibrate and delaminate, the glue locking and packaging difficulty is increased, and the performance stability of the manufactured product is influenced.

Disclosure of Invention

In order to solve the deficiencies existing in the prior art, the utility model provides a can improve the lock and glue the function, the more stable 28 pin integrated circuit lead frames of performance.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: the utility model provides a 28 pin integrated circuit lead frame, includes a plurality of repetitive arrangement's lead frame unit, the lead frame unit include the base island, the base island distribute twenty eight pins all around, the interior tip of every pin all be provided with the solder joint, the outer end of pin to the horizontal both sides of base island extend, with every the same side every the outer end of pin between connect through first splice bar, every the pin on and be located the solder joint with first splice bar between all seted up horizontal pre-cut, horizontal pre-cut all be located same water flat line make the both sides of base island form symmetrical pre-cut groove.

In some embodiments, the lateral precuts include a first precut, a second precut and a third precut arranged in parallel, the first precut and the third precut are arranged on the lower surface of the pin, the second precut is arranged on the upper surface of the pin and is positioned between the first precut and the third precut, the cross sections of the first precut, the second precut and the third precut are triangular, the opening size and the opening depth are the same, and the opening angle ranges from 55 ° to 65 °. From this have better lock and glue the function, the cohesion of reinforcing colloid and substrate avoids the pin outer end to be drawn the aversion, can reduce the vibration when die-cut during die-cut to avoid the fracture layering.

In some embodiments, twenty eight of the pins are sequentially divided into a first pin area, a second pin area, a third pin area and a fourth pin area in a clockwise direction, the first pin area comprises eight pins, the second pin area comprises six pins, the third pin area comprises eight pins, the fourth pin area comprises six pins, the first pin area and the third pin area are arranged on the upper side and the lower side of the base island relatively, the second pin area and the fourth pin area are arranged on the left side and the right side of the base island relatively, and the pins of the second pin area and the fourth pin area are provided with first glue locking holes. The structural layout of each pin district is reasonable compact, thereby sets up the lock gluey hole and guarantee better lock gluey function, strengthens the cohesion of colloid and substrate, and difficult layering is loose when cutting off, avoids the pin outer end to be pulled the aversion.

In some embodiments, the area of the first glue hole gradually increases from the base island to the outside, and the first glue hole is disposed near the precut groove. The bonding force of the outer side is weaker, so that the structure has a better glue locking effect.

In some embodiments, the lead pads of the first lead area and the third lead area are both T-shaped pads, and the center distance between adjacent leads is 0.635 mm; the width of the pin welding spot of the second pin area and the fourth pin area is 0.190mm, and the center distance between the adjacent pins is 0.370 mm; the first precut, the second precut and the third precut are arranged at equal intervals, and the distance is 0.150 mm. In the structure, the T-shaped welding spot can play a role in protection, so that layering and gold wire damage are prevented in the glue drawing process, and the bonding force between the welding spot and the pin is enhanced; the layout among all pins is compact; the arrangement of the pre-cuts is beneficial to fixing and tensioning the colloid and the base material, the binding force is enhanced, and the vibration during punching can be reduced, so that cracking and delamination are avoided.

In some embodiments, the left and right ends of the base island are provided with second glue locking holes, the second glue locking holes are formed by a middle rectangular hole and two semicircular holes at two ends, the second glue locking holes include a-type second glue locking hole, a B-type second glue locking hole and a C-type second glue locking hole, the a-type second glue locking hole and the B-type second glue locking hole are distributed at one end of the base island, the two C-type second glue locking holes are distributed at the other end of the base island, and the length relationship of the second glue locking holes is as follows: the A-type second glue locking hole is larger than the C-type second glue locking hole is larger than the B-type second glue locking hole, and the width of the second glue locking holes is the same. Therefore, the packaging structure has a better adhesive locking function and enables the performance of the packaging body to be more stable.

In some embodiments, the lead frame assembly further comprises a support body and a plurality of lead frame groups, wherein the lead frame groups are fixedly arranged in the support body at intervals, adjacent lead frame groups are connected through longitudinal ribs, and the lead frame units are longitudinally arranged in each lead frame group. The longitudinal ribs strengthen the overall and local strength, facilitate subsequent processing, lead frame groups are compactly arranged, the unit yield is greatly increased, and the single cost is reduced.

In some embodiments, the left and right sides of the base island are connected with the longitudinal rib through a second connecting rib, the base island is recessed downwards, so that the depth difference between the base island and the lead is 0.2030 ± 0.008mm, the thickness of the base island is 0.1650 ± 0.026mm, and the connection part of the second connecting rib and the base island is in a slope of 30 degrees. The downward depression of the base island is beneficial to rapid glue feeding during packaging.

In some embodiments, a longitudinal pre-cut is provided on a lower surface of the second tie bar at a position adjacent to the longitudinal bar, and the cross-sectional shape of the longitudinal pre-cut is triangular, and the opening angle is in the range of 55-65 °. The longitudinal pre-cut can also enhance the function of locking glue, enhance the binding force of the glue and the base material, avoid the second connecting rib from being pulled and shifted, and reduce the vibration during punching so as to avoid cracking and layering.

In some embodiments, the center distance between the vertically adjacent lead frame units is 7.95-8.05 mm, the center distance between the horizontally adjacent lead frame units is 13.20-13.30 mm, each longitudinal rib is provided with a plurality of through holes for releasing stress during glue injection, and the upper side and the lower side of the bracket body are provided with a plurality of positioning holes respectively.

Compared with the prior art, the utility model has the advantages of: its pin number of integrated circuit lead frame of 28 pins is many, and is functional strong, can satisfy the needs of different chip encapsulation, the utility model discloses a set up a plurality of incisions in advance and lock gluey hole in different positions, make the colloid flow during the encapsulation, be favorable to the colloid to fill, with colloid and substrate fixed taut, strengthen binding force, it is loose to be difficult for the layering when cutting off to improved the lead frame and glued the ability to the lock of high temperature melting likepowder colloid in packaging process, improved the stability and the reliability of packaging body.

Drawings

Fig. 1 is a schematic structural diagram of a lead frame unit according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along A-A of FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1;

FIG. 4 is a cross-sectional view taken along C-C of FIG. 1;

fig. 5 is a schematic structural view of a bracket body according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a part of a lead frame assembly according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples, but the present invention is not limited thereto.

Example one

As shown in the figure, a 28-pin integrated circuit lead frame comprises a plurality of repeatedly arranged lead frame units 1, each lead frame unit 1 comprises a base island 2, twenty-eight pins 3 are distributed around the base island 2, the inner end portion of each pin 3 is provided with a welding spot 4, the outer end of each pin 3 extends to the two horizontal sides of the base island 2, the outer ends of the pins 3 on the same side are connected through a first connecting rib 5, a transverse pre-cut 6 is arranged on each pin 3 and located between the welding spot 4 and the first connecting rib 5, and the transverse pre-cut 6 is located on the same horizontal line to enable the two sides of the base island 2 to form symmetrical pre-cut grooves 7.

Example two

The 28-pin integrated circuit lead frame proposed in this embodiment defines the specific structure of the transverse pre-cut on the basis of the first embodiment. In the present embodiment, the transverse pre-cuts 6 include a first pre-cut 8, a second pre-cut 9 and a third pre-cut 10 arranged in parallel, the first pre-cut 8 and the third pre-cut 10 are arranged on the lower surface of the pin 3, the second pre-cut 9 is arranged on the upper surface of the pin 3 and is located between the first pre-cut 8 and the third pre-cut 10, the cross sections of the first pre-cut 8, the second pre-cut 9 and the third pre-cut 10 are all triangular, the opening size and the opening depth are the same, and the opening angle ranges from 55 ° to 65 °, and is preferably 60 °.

EXAMPLE III

The 28-pin integrated circuit lead frame proposed in this embodiment further supplements the latch structure on the basis of the first embodiment. In this embodiment, twenty-eight pins 3 are sequentially divided into a first pin area 11, a second pin area 12, a third pin area 13, and a fourth pin area 14 in a clockwise direction, where the first pin area 11 includes eight pins, the second pin area 12 includes six pins, the third pin area 13 includes eight pins, the fourth pin area 14 includes six pins, the first pin area 11 and the third pin area 13 are disposed on the upper and lower sides of the base island 2, the second pin area 12 and the fourth pin area 14 are disposed on the left and right sides of the base island 2, and the pins of the second pin area 12 and the fourth pin area 14 are all provided with first glue locking holes 15.

In this embodiment, the area of the first glue hole 15 gradually increases from the base island 2 to the outside, and the first glue hole 15 is disposed at a position close to the precut groove 7.

In the embodiment, the pin welding spots of the first pin area and the third pin area are both T-shaped welding spots, and the center distance between the adjacent pins is 0.635 mm; the width of the pin welding spot of the second pin area and the fourth pin area is 0.190mm, and the center distance between the adjacent pins is 0.370 mm; the first precut, the second precut and the third precut are arranged at equal intervals, and the interval is 0.075 mm.

In this embodiment, second locking glue hole 16 has been seted up at both ends about base island 2, second locking glue hole 16 comprises middle part rectangular hole and the semicircular hole in both ends, the second locking glue hole includes a type second locking glue hole 17, B type second locking glue hole 18 and C type second locking glue hole 19, A type second locking glue hole 17 and B type second locking glue hole 18 distribute in the one end of base island 2, two C type second locking glue holes 19 distribute in the other end of base island 2, the length relation in second locking glue hole is: the type A second glue locking hole is larger than the type C second glue locking hole and is larger than the type B second glue locking hole, and the width of the second glue locking holes is the same.

Example four

The 28-pin integrated circuit lead frame proposed by the present embodiment further defines the overall structure of the lead frame on the basis of the above embodiments. In this embodiment, the lead frame further includes support body 20 and multiseriate lead frame group 21, and multiseriate lead frame group 21 interval is fixed to be set up in support body 20, connects through vertical muscle 22 between the adjacent lead frame group 21, and a plurality of lead frame units 1 are vertically arranged in every lead frame group 21.

The left side and the right side of the base island 2 are connected with the longitudinal ribs 22 through the second connecting ribs 23, the base island 2 is sunken downwards, the depth difference between the base island 2 and the pins 3 is 0.2030 +/-0.008 mm, the thickness of the base island 2 is 0.1650 +/-0.026 mm, and the connecting part of the second connecting ribs 23 and the base island 2 is in a 30-degree slope.

A longitudinal pre-cut 24 is arranged on the lower surface of the second connecting rib 23 and close to the longitudinal rib 22, the cross section of the longitudinal pre-cut 24 is triangular, and the opening angle ranges from 55 degrees to 65 degrees.

The center distance between the upper and lower adjacent lead frame units 1 is 7.95-8.05 mm, the center distance between the left and right adjacent lead frame units 1 is 13.20-13.30 mm, each longitudinal rib 22 is provided with a plurality of through holes 25 for releasing stress during glue injection, and the upper and lower sides of the support body 20 are provided with a plurality of positioning holes 26 respectively.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and the present invention can also be modified in materials and structures, or replaced by technical equivalents. Therefore, all structural equivalents which may be made by applying the present invention to the specification and drawings, or by applying them directly or indirectly to other related technical fields, are intended to be encompassed by the present invention.

Claims

1. The utility model provides a 28 pin integrated circuit lead frame, includes a plurality of repetitive arrangement's lead frame unit, the lead frame unit include the base island, its characterized in that, the base island distribute twenty eight pins all around, every the interior tip of pin all be provided with the solder joint, the outer end of pin to the horizontal both sides of base island extend, with every the outer end of pin between connect through first splice bar, every the pin on and be located the solder joint with first splice bar between all seted up horizontal pre-cut, horizontal pre-cut all be located same water flat line make the both sides of base island form symmetrical pre-cut groove.

2. The 28-pin integrated circuit lead frame according to claim 1, wherein the lateral pre-cuts comprise a first pre-cut, a second pre-cut and a third pre-cut arranged in parallel, the first pre-cut and the third pre-cut are arranged on the lower surface of the pin, the second pre-cut is arranged on the upper surface of the pin and located between the first pre-cut and the third pre-cut, the cross sections of the first pre-cut, the second pre-cut and the third pre-cut are all triangular, the size and the depth of the opening are the same, and the angle of the opening ranges from 55 ° to 65 °.

3. The 28-pin integrated circuit lead frame according to claim 2, wherein twenty eight of the pins are sequentially divided into a first pin area, a second pin area, a third pin area and a fourth pin area in a clockwise direction, the first pin area comprises eight pins, the second pin area comprises six pins, the third pin area comprises eight pins, the fourth pin area comprises six pins, the first pin area and the third pin area are oppositely arranged on the upper side and the lower side of the base island, the second pin area and the fourth pin area are oppositely arranged on the left side and the right side of the base island, and the pins of the second pin area and the fourth pin area are respectively provided with a first glue locking hole.

4. The 28-pin integrated circuit lead frame according to claim 3, wherein the area of the first glue-locking hole gradually increases from the base island to the outside, and the first glue-locking hole is disposed near the pre-cutting groove.

5. The 28-pin integrated circuit lead frame according to claim 3, wherein the pin pads of the first and third pin areas are T-shaped pads, and the center-to-center distance between adjacent pins is 0.635 mm; the width of the pin welding spot of the second pin area and the fourth pin area is 0.190mm, and the center distance between the adjacent pins is 0.370 mm; the first precut, the second precut and the third precut are arranged at equal intervals, and the distance is 0.150 mm.

6. The 28-pin integrated circuit lead frame according to claim 3, wherein second glue locking holes are formed in the left and right ends of the base island, the second glue locking holes are formed by a middle rectangular hole and two end semicircular holes, the second glue locking holes include a-type second glue locking hole, a B-type second glue locking hole and a C-type second glue locking hole, the a-type second glue locking hole and the B-type second glue locking hole are distributed at one end of the base island, the two C-type second glue locking holes are distributed at the other end of the base island, and the length relationship of the second glue locking holes is as follows: the A-type second glue locking hole is larger than the C-type second glue locking hole is larger than the B-type second glue locking hole, and the width of the second glue locking holes is the same.

7. The 28-pin integrated circuit lead frame according to claim 1, further comprising a frame body and a plurality of lead frame groups, wherein the plurality of lead frame groups are fixedly arranged in the frame body at intervals, adjacent lead frame groups are connected by longitudinal ribs, and the plurality of lead frame units are longitudinally arranged in each lead frame group.

8. The 28-pin integrated circuit lead frame according to claim 7, wherein the left and right sides of the base island are connected to the longitudinal ribs through second connecting ribs, the base island is recessed downward, so that the depth difference between the base island and the pins is 0.2030 ± 0.008mm, the thickness of the base island is 0.1650 ± 0.026mm, and the connecting portion of the second connecting ribs and the base island is inclined at 30 °.

9. The 28-pin integrated circuit lead frame according to claim 8, wherein a longitudinal pre-cut is provided on the lower surface of the second bonding rib and adjacent to the longitudinal rib, the cross-sectional shape of the longitudinal pre-cut is triangular, and the opening angle is in the range of 55 ° to 65 °.

10. The 28-pin integrated circuit lead frame according to claim 7, wherein the center distance between the upper and lower adjacent lead frame units is 7.95-8.05 mm, the center distance between the left and right adjacent lead frame units is 13.20-13.30 mm, each longitudinal rib is provided with a plurality of through holes for releasing stress during glue injection, and the upper and lower edges of the bracket body are provided with a plurality of positioning holes respectively.