QFN lead frame

Abstract

The utility model discloses a QFN lead frame, which comprises a base island, a plurality of cutting channel connecting ribs located on the outer ring of the base island, a plurality of first connecting ribs arranged between the base island and the cutting channel connecting ribs, a plurality of first pins and a plurality of second pins, and the plurality of first pins are connected to the cutting channel connecting ribs; a second connecting rib is further arranged between every two adjacent first connecting ribs, and the multiple second pins are connected to the second connecting ribs. According to the utility model, the second connecting rib is arranged between the two first connecting ribs, and the plurality of second pins are fixed on the second connecting rib, so that the second pins do not need to pass through gaps between the first pins through a pin connecting rib and then are fixed on the cutting channel connecting rib, and the installation of the first pins and the installation of the second pins do not interfere with each other; the number of the pins of the whole frame can be more.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a QFN lead frame. Background Art

[0002] Double-circle QFN is a common integrated circuit packaging form, which has high integration and good electrical performance.

[0003] like Figure 1 As shown, the current QFN frame includes outer ring pins 130 and inner ring pins 120. The outer ring pins 130 are directly fixed on the cutting path connecting ribs 110, and the inner ring pins 120 need to pass through the gaps between the outer ring pins 130 through the pin connecting ribs 121 and then be fixed to the cutting path connecting ribs 110.

[0004] This arrangement has the following defects: first, since the pin connecting rib needs to pass through the gap between the two outer ring pins, the gap between the two outer ring pins is too large, and the number of pins that can be accommodated is limited; second, in order to allow the pin connecting rib of the inner ring pin to pass between the two outer ring pins, a semi-etched area needs to be designed on the front side of the frame, which reduces the welding wire space of the outer ring pin; third, after the cutting path connecting rib is cut, cutting burrs will be generated between the pin connecting rib and the outer ring pin, which will cause the pin connecting rib to contact the outer ring pin and cause a short circuit. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to propose a QFN lead frame for solving the problem in the prior art that the number of pins is limited due to the need for the pin connecting ribs to pass through the gaps between the outer ring pins.

[0006] The technical solution adopted by the utility model to solve the technical problem is a QFN lead frame, comprising a base island, a plurality of cutting path connecting ribs located on the outer ring of the base island, and a plurality of first connecting ribs arranged between the base island and the cutting path connecting ribs, and also comprising a plurality of first pins and a plurality of second pins, wherein the plurality of first pins are connected to the cutting path connecting ribs;

[0007] A second connecting rib is further provided between two adjacent first connecting ribs, and a plurality of the second pins are connected to the second connecting rib.

[0008] Furthermore, four cutting track connecting ribs are arranged on the outer ring of the base island, and four first connecting ribs are arranged between the base island and the four cutting track connecting ribs;

[0009] At least one second connecting rib is disposed between every two adjacent first connecting ribs, and a plurality of second pins are disposed on each of the second connecting ribs.

[0010] Furthermore, a third connecting rib is provided between any two adjacent first connecting ribs, and a plurality of third pins are provided on the third connecting rib.

[0011] Furthermore, each of the cutting lane connecting ribs has a second connecting rib and a third connecting rib parallel thereto.

[0012] Furthermore, it also includes a plurality of fourth pins, and the plurality of fourth pins are connected to the base island.

[0013] Compared with the prior art, the utility model has at least the following beneficial effects:

[0014] 1. A second connecting rib is arranged between two first connecting ribs, and a plurality of second pins are fixed on the second connecting rib, so that the second pins do not need to pass through the gap between the first pins through a pin connecting rib and then be fixed on the cutting path connecting rib. The installation of the first pin and the second pin will not interfere with each other, and the number of pins of the entire frame can be set to be more.

[0015] 2. There is no need for pin connecting ribs to pass through the first pins, and there is no need to set a half-etched area between the first pins, thereby increasing the welding wire space of the first pins.

[0016] 3. Since the second pin is directly fixed to the second connecting rib, and the second connecting rib does not need to pass through the gap between the first pins, after the cutting rib is cut, the burrs generated by the first pin will not contact the second pin to cause a short circuit, thereby ensuring the yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a lead frame in the background technology;

[0018] Figure 2 It is a schematic diagram of the structure of the lead frame when the first pin and the second pin are provided at the same time in the embodiment;

[0019] Figure 3 It is a schematic structural diagram of the lead frame when the first pin, the second pin and the third pin are provided at the same time in the embodiment;

[0020] Figure 4 It is a schematic diagram of the structure of the lead frame when the first pin, the second pin and the fourth pin are provided at the same time in the embodiment;

[0021] In the figure:

[0022] 100, base island; 110, cutting path connecting rib; 120, inner ring pin; 121, pin connecting rib; 130, outer ring pin; 140, first connecting rib; 150, second connecting rib; 160, third connecting rib;

[0023] 200, first pin;

[0024] 300, second pin;

[0025] 400, third pin;

[0026] 500, fourth pin. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0028] Please refer to Figure 2-Figure 4 The utility model discloses a QFN lead frame, comprising a base island 100, a plurality of cutting path connecting ribs 110 located at the outer ring of the base island 100, and a plurality of first connecting ribs 140 arranged between the base island 100 and the cutting path connecting ribs 110, and also comprising a plurality of first pins 200 and a plurality of second pins 300, wherein the plurality of first pins 200 are connected to the cutting path connecting ribs 110;

[0029] A second connecting rib 150 is further disposed between two adjacent first connecting ribs 140 , and a plurality of the second pins 300 are connected to the second connecting rib 150 .

[0030] Specifically, the first pin 200 in the present application is the outer ring pin, which is directly fixed on the cutting path connecting rib 110, and at the same time, a second connecting rib 150 is arranged between the two first connecting ribs 140, and multiple second pins 300 (i.e., inner ring pins) are fixed on the second connecting rib 150, so that the second pin 300 does not need to pass through the gap between the first pins 200 through a pin connecting rib 121 and then be fixed on the cutting path connecting rib 110. The installation of the first pin 200 and the second pin 300 will not interfere with each other, and the number of pins of the entire frame can be set to be more; there is no need for the first pins 200 to pass through the pin connecting rib 121, and there is no need to set a half-etching area between the first pins 200, which increases the welding wire space of the first pin 200.

[0031] At the same time, since the second pin 300 is directly fixed to the second connecting rib 150, and the second connecting rib 150 does not need to pass through the gap between the first pins 200, after the cutting rib 110 is cut, the burrs generated by the first pin 200 will not contact the second pin 300 to cause a short circuit, thereby ensuring the yield of the product.

[0032] For further information, please refer to Figure 2 , four cutting path connecting ribs 110 are arranged on the outer circle of the base island 100, and four first connecting ribs 140 are arranged between the base island 100 and the four cutting path connecting ribs 110;

[0033] At least one second connecting rib 150 is disposed between every two adjacent first connecting ribs 140 , and each second connecting rib 150 is disposed with a plurality of second pins 300 .

[0034] Specifically, four cutting path connecting ribs 110 are arranged on the outer circle of the base island 100, and a first connecting rib 140 connected to the cutting path connecting rib 110 is respectively arranged at the four outer corners of the base island 100, and then a second connecting rib 150 is arranged on the first connecting rib 140, and the first pin 200 is arranged on the cutting path connecting rib 110, and the second pin 300 is arranged on the second connecting rib 150.

[0035] For further information, please refer to Figure 3 A third connecting rib 160 is further provided between any two adjacent first connecting ribs 140 , and a plurality of third pins 400 are provided on the third connecting rib 160 .

[0036] Furthermore, each of the cutting lane connecting ribs 110 has a second connecting rib 150 and a third connecting rib 160 parallel thereto.

[0037] Specifically, one or more third connecting ribs 160 may be arranged on the first connecting rib 140 in parallel with the second connecting rib 150 , and a plurality of third pins 400 may be arranged on the third connecting rib 160 .

[0038] For further information, please refer to Figure 4 , further comprising a plurality of fourth pins 500 , wherein the plurality of fourth pins 500 are connected to the base island 100 .

[0039] Of course, the space on the side of the base island 100 can also be used to directly fix the fourth pin 500 on the side of the base island 100 .

[0040] All of the above can prevent the connecting rib from passing through the gap of the first pin 200 .

[0041] After completing the manufacture of the above-mentioned frame, the frame needs to be pre-molded; then, the copper material between the second pin 300 and the second connecting rib 150 is exposed by exposure and development, the copper material between the third pin 400 and the third connecting rib 160 is exposed, and the copper material between the fourth pin 500 and the base island 100 is exposed, and the remaining positions are covered with photoresist (or covered with a pressing plate jig), and then the copper material is etched with a solution, and then the photoresist is removed (the pressing plate jig is removed), and the operation of disconnecting the first pin 200, the second pin 300, the third pin 400 and the fourth pin 500 is completed; finally, the frame can be packaged normally.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A QFN lead frame, comprising a base island, a plurality of cutting path connecting ribs located on the outer ring of the base island, and a plurality of first connecting ribs arranged between the base island and the cutting path connecting ribs, characterized in that: It also includes a plurality of first pins and a plurality of second pins, wherein the plurality of first pins are connected to the cutting path connecting ribs; A second connecting rib is further provided between two adjacent first connecting ribs, and a plurality of the second pins are connected to the second connecting rib.

2. A QFN lead frame according to claim 1, characterized in that: Four cutting track connecting ribs are arranged on the outer ring of the base island, and four first connecting ribs are arranged between the base island and the four cutting track connecting ribs; At least one second connecting rib is disposed between every two adjacent first connecting ribs, and a plurality of second pins are disposed on each of the second connecting ribs.

3. A QFN lead frame according to claim 1, characterized in that: A third connecting rib is provided between any two adjacent first connecting ribs, and a plurality of third pins are provided on the third connecting rib.

4. A QFN lead frame according to claim 3, characterized in that: Each of the cutting path connecting ribs has a second connecting rib and a third connecting rib parallel thereto.

5. The QFN lead frame according to claim 1, characterized in that: It also includes a plurality of fourth pins, wherein the plurality of fourth pins are connected to the base island.

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