CN219811496U - Lead frame structure and lead frame - Google Patents

Abstract

The utility model provides a lead frame structure and a lead frame, and relates to the technical field of chip packaging, wherein the lead frame structure comprises: the base island and the connecting ribs; the base island is fixed in the central area of the frame structure through connecting ribs; the connecting rib comprises: a support angle and a connecting rib; the support angle is fixed at the edge area of the frame structure; one end of the connecting rib is fixedly connected with the base island, and the other end of the connecting rib is fixedly connected with the supporting angle; the connecting ribs are provided with a first groove and a second groove along the stress releasing direction of the base island; the first groove and the second groove are oppositely staggered and are separated by a preset distance; wherein, the preset distance is smaller than the length of the connecting rib. Through optimizing the even muscle structure of frame, set up the recess of staggering in opposition, form one and can provide potential energy absorbing structure, can prevent effectively that the stress on the frame from transmitting to on the chip frame connecting strip, played the effect of improving the frame warpage, improved lead frame structure's stability.

Description

Lead frame structure and lead frame

Technical Field

The utility model relates to the technical field of chip packaging, in particular to a lead frame structure and a lead frame.

Background

DFN or QFN is a flat no-lead chip package, DFN (dual flat no-leaded package) is a dual-sided flat no-lead package, and QFN (quad flat no-leaded package) is a quad flat no-lead package, both of which require a lead frame. The lead frame is formed by stamping a copper sheet or through an etching process and comprises a plurality of lead frame structure units, the lead frame structure units are connected through connecting ribs to form an array, then a chip is adhered to the lead frame, a silk thread is bonded to the lead frame, plastic packaging is carried out, and finally cutting and separating are carried out, so that a single packaged product is obtained.

The existing QFN & DFN packaging lead frame unit has higher and higher density, and the difference of thermal expansion coefficients among the chip, the silver adhesive and the frame can lead the lead frame to warp in a high-temperature heating state of a wire bonding station, so that adverse effects are generated on the following procedures and the reliability of products.

Disclosure of Invention

The embodiment of the utility model aims to provide a lead frame structure, which can form a structure capable of providing potential energy absorption by optimizing a connecting rib structure of a frame and arranging oppositely staggered grooves, effectively prevent stress on the frame from being transmitted to a web connecting strip, and achieve the effect of improving the warping of the frame, so that the production efficiency is not influenced, the process condition is not changed, and the quality of the production efficiency is ensured, thereby solving the technical problems.

The embodiment of the utility model provides a lead frame structure, which comprises the following components: the base island and the connecting ribs; the base island is fixed in the central area of the frame structure through connecting ribs; the connecting rib comprises: a support angle and a connecting rib; the support angle is fixed at the edge area of the frame structure; one end of the connecting rib is fixedly connected with the base island, and the other end of the connecting rib is fixedly connected with the supporting angle; the connecting ribs are provided with a first groove and a second groove along the stress releasing direction of the base island; the first grooves and the second grooves are oppositely staggered and are spaced by a preset distance; wherein, the preset distance is smaller than the length of the connecting rib.

In the implementation process, the connecting rib structure of the frame is optimized, the oppositely staggered grooves are formed, so that a structure capable of providing potential energy absorption is formed, stress on the frame can be effectively prevented from being transmitted to the chip frame connecting strip, and the effect of improving the warping of the frame is achieved. By arranging the oppositely staggered grooves in the connecting rib structure of the optimized frame, the production efficiency is not affected, the process conditions are not changed, the quality of the production efficiency is ensured, and the stability of the lead frame structure is improved.

Optionally, the island stress release direction is a direction in which a central region of the frame structure is released toward an edge region.

In the implementation process, the stress on the base island is effectively prevented from being transmitted to the edge connecting strip, so that the effect of improving the warping of the frame is achieved, the structure is simple, and the cost is reduced.

Optionally, the shape of the base island is rectangular; the connecting rib comprises: the first rib connecting part, the second rib connecting part, the third rib connecting part and the fourth rib connecting part; the first rib connecting part, the second rib connecting part, the third rib connecting part and the fourth rib connecting part are positioned at four corners of the base island; the base island is fixed in the central area of the frame structure through the first connecting rib part, the second connecting rib part, the third connecting rib part and the fourth connecting rib part.

In the implementation process, the base island is firmly fixed in the central area on the frame by the force of four corners of the frame, so that the falling off caused by the follow-up chip installation and welding wire installation is effectively prevented, and the stability of lead packaging is improved.

Optionally, the frame structure further comprises: the pins are positioned in the peripheral area of the base island; the connecting ribs divide the peripheral area into four areas uniformly, and the pins are symmetrically arranged in the four areas relative to the center of the base island.

In the implementation process, the stress generated in the chip packaging process can be directly transmitted to the edge outer wall connecting strip through the connecting ribs without passing through the pin area, the edge outer wall connecting strip extrudes the inner wall of the semiconductor package, and then the connection firmness of the edge outer wall connecting strip and the semiconductor package is improved, pins caused by subsequent chip and welding lines are effectively prevented from falling off, and the stability of lead packaging is improved.

Optionally, the chip connected on the base island is connected with the pin through a bonding wire.

In the implementation process, the chip, the bonding wires, the connecting ribs and the pins in the base island region form a whole, and when the base island region is subjected to warp deformation, stress can be transmitted to the edge of the outer wall through the connecting ribs in the base island region, so that the stress transmission is ensured, and the utilization rate of the base island, the chip and the pins is improved.

Optionally, the first groove and the second groove are arranged on the connecting rib in a staggered manner along a direction perpendicular to the central area; the first groove and the second groove are the same in size.

In the implementation process, the first grooves and the second grooves with the same size are formed in the connecting ribs in a staggered manner along the stress release direction, so that the released stress can be buffered step by step, and meanwhile, the concave grooves with the same size can be balanced better in the connection stability and the stress release.

Optionally, the shape of the first groove and the second groove is square or rectangular.

In the implementation process, the connecting ribs are provided with the first grooves and the second grooves which are in square or rectangular shapes in a staggered manner along the stress release direction, and compared with the grooves in oval or diamond shapes and the like, the connecting ribs are large in area, so that the stress is released more easily, and the occurrence of warping is further avoided.

Optionally, the recess depth of the first groove and the second groove is not more than half the width of the connecting rib.

In the implementation process, the opening depth of the first groove and the second groove is kept within a range smaller than one half of the width of the connecting rib, so that the occurrence of bending collapse can be reduced, and the stability of fixing the base island region is improved.

Optionally, the frame structure further comprises: plastic packaging material; and the plastic packaging material packages the base island, the pins and the connecting ribs into an integral frame.

In the implementation process, the plastic package material wraps the base island, the pins and the connecting ribs, so that the strength and the supporting strength of the pins are stronger, deformation of the base island or the pins caused by multiple bonding can be avoided, the cost is reduced, and the performance of the frame structure is optimized.

In a second aspect, an embodiment of the present utility model provides a leadframe, where the leadframe includes a plurality of leadframe structures, and the leadframe structures are any one of the leadframe structures described above.

In the implementation process, the lead frame comprises a plurality of frame structure units with the optimized connecting rib structures, and the connecting ribs are provided with the oppositely staggered grooves, so that the warping stress of the chip can be well buffered, the production efficiency is not affected, the process conditions are not changed, the quality of the production efficiency is ensured, and the stability of the chip package is improved.

In order to make the above objects, features and advantages of the present utility model more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments of the present utility model will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present utility model and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a leadframe structure according to an embodiment of the present utility model;

fig. 2 is a partial enlarged view of a leadframe structure according to an embodiment of the present utility model.

Icon: 01-lead frame structure; 10-islands; 20-connecting ribs; 201-a first web portion; 202-a second web portion; 203-a third web portion; 204-fourth connecting rib part; 21-support angle; 22-connecting ribs; 221-a first groove; 222-a second groove; 30-pins.

Detailed Description

The technical solutions in the embodiments of the present utility model will be described below with reference to the accompanying drawings in the embodiments of the present utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Also, in the description of the present utility model, the terms "first," "second," and the like are used merely to distinguish one from another and are not to be construed as indicating or implying any actual such relationship or order between such entities or operations. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "upper", "lower", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or directions or positional relationships that are conventionally visited when the inventive product is used, are merely for convenience in describing the present utility model and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limitations of the present utility model.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the connection may be direct or indirect via an intermediate medium, or may be internal communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The inventor notes that the conventional process flow of the current DFN & QFN packaging patch and wire bonding station is as follows: dispensing, pasting, curing silver paste, plasma and welding wires. (1) dispensing: fixing the DFN & QFN frame on a transmission track, and dispensing the glue on the frame PAD by a glue dispensing system; (2) Patch: picking up and welding the chip on the frame PAD through a chip picking up and welding structure; (3) silver colloid curing: placing the patch-completed material sheet into a high-temperature oven for silver colloid solidification, so that good welding is formed between the chip and the frame; (4) Plasma: performing Plasma cleaning on the material sheet subjected to chip welding to remove oxides and contamination on the surface of the material sheet, so that the quality of welding wires is more stable; (5) welding wire: the web is secured to the wire bonding machine rail and the wire bonding system bonds at the die pad and frame pins. Because the density of the lead frame units of the QFN & DFN package is higher and higher, the difference of thermal expansion coefficients among the chip, the silver adhesive and the frame can lead the material sheet (the frame) to warp in a high-temperature heating state of the wire bonding station, and the subsequent process and the reliability of products are affected. There are two types of current solutions: 1. reducing the unit density within the frame, which reduces production efficiency; 2. lowering the wire temperature may affect wire quality or wire reliability. In view of this, in order to solve the problem of frame warpage after the wire bonding station during the DFN & QFN package production process, the present utility model proposes a lead frame structure 01 and a lead frame as described below by optimizing the frame pad tie bar structure.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a leadframe structure 01 according to an embodiment of the present utility model. The embodiments of the present utility model will be explained in detail below. The lead frame structure 01 includes: a base island 10 and a connecting rib 20; the base island 10 is fixed in the central area of the frame structure through a connecting rib 20; the connecting rib 20 includes: a support angle 21 and a connecting rib 22; the supporting angle 21 is fixed at the edge area of the frame structure; one end of the connecting rib 22 is fixedly connected with the base island 10, and the other end of the connecting rib 22 is fixedly connected with the supporting angle 21; the connecting rib 22 is provided with a first groove 221 and a second groove 222 along the stress releasing direction of the base island 10; the first groove 221 and the second groove 222 are arranged in a staggered manner relatively and are spaced apart from each other by a preset distance; wherein the predetermined distance is less than the length of the connecting rib 22.

Illustratively, the base island 10 may be: a large-area bare bonding pad area arranged at the center of the lead frame unit is used for conducting heat and connecting and fixing a chip; around the periphery of the package of large pads there are typically conductive pads (pins 30) that make electrical connection. For two common DFN packages and QFN packages, the base island 10 of the DFN package is provided with bonding pads on two sides, and bonding pads are arranged on the periphery of the base island 10 of the QFN package, and the QFN package is not provided with gull-wing leads like the traditional SOIC and TSOP packages, so that the conductive paths between the inner pins 30 and the bonding pads are short, the self-inductance coefficient and the wiring resistance in the package are very low, and excellent electrical performance can be provided; in addition, it provides excellent heat dissipation through the exposed leadframe pad, which has direct heat dissipation channels for releasing heat within the package. The connecting ribs 20 may be: the strip-shaped elastic structure used for connecting and fixing the base island 10 can be used for selecting materials with larger elastic coefficients from the aspect of material selection of the connecting ribs 20.

Alternatively, as shown in fig. 1, the base island 10 is fixed on a central pad area of a lead frame structure 01 of a DFN package or a QFN package through a connecting rib 20, wherein the connecting rib 20 is specifically formed by two parts of a supporting corner 21 and a connecting rib 22. The supporting legs can be separated into two angles, which is more beneficial to fixation; the connecting rib 22 is provided with two concave grooves along the stress release direction of the base island 10: first groove 221 and second groove 222, as seen in the top plan view of fig. 2: the first groove 221 and the second groove 222 are relatively staggered and spaced apart from each other by a predetermined distance. The bifurcated supporting corner 21 can be fixed on the edge area of the lead frame structure 01 of the DFN package or the QFN package by welding or screws, one end of the strip-shaped connecting rib 22 is integrally connected with the base island 10 in the middle square area, and the other end of the connecting rib 22 is integrally connected with the supporting corner 21. The two concave grooves such as the first groove 221 and the second groove 222 are arranged to enable the connecting rib 20 to have a spring buffering function, so that stress released by the base island 10 area is buffered, the stress on the base island 10 is effectively prevented from being transmitted to the frame connecting strip, and the effect of improving the frame warping is achieved.

Through optimizing the structure of the connecting ribs 20 of the frame, the oppositely staggered grooves are formed, a structure capable of providing potential energy absorption is formed, stress on the frame can be effectively prevented from being transmitted to the connecting strips of the chip frame, the effect of improving the warping of the frame is achieved, the production efficiency is not affected, the process condition is not changed, the quality of the production efficiency is guaranteed, and the stability of the lead frame structure 01 is improved.

In one embodiment, the stress relief direction of the islands 10 is the direction of relief of the central region of the frame structure to the edge regions.

Illustratively, the provision of two concave grooves, such as the first groove 221 and the second groove 222, provides the tie bar 20 with a spring cushioning function. Because the thermal expansion coefficient of the central area of the base island 10 is smaller, the thermal expansion coefficients of the periphery and the edge area of the base island 10 are larger, and the thermal expansion and contraction (heating and cooling) are generated when the wire bonding machine bonds wires, the change of the central area of the base island 10 is slower, and the displacement is smaller; the peripheral and edge areas change faster, and the generated displacement is larger; a central stress is generated to diffuse from the central area of the base island 10 to the edge, is buffered once through the first groove 221 and once through the second groove 222, and is basically released when reaching the edge, so that the stress on the base island 10 is effectively prevented from being transferred to the edge connecting strip, the effect of improving the warping of the frame is achieved, the structure is simple, and the cost is reduced.

In one embodiment, the shape of the island 10 is rectangular; the connecting rib 20 includes: a first rib connecting portion 201, a second rib connecting portion 202, a third rib connecting portion 203, and a fourth rib connecting portion 204; the first rib connecting part 201, the second rib connecting part 202, the third rib connecting part 203 and the fourth rib connecting part 204 are positioned at four corners of the base island 10; the island 10 is fixed to a central region of the frame structure by a first rib connecting portion 201, a second rib connecting portion 202, a third rib connecting portion 203, and a fourth rib connecting portion 204.

Illustratively, as shown in fig. 1, the shape of the land 10 area may be square or rectangular in fig. 2, and generally the QFN package is square, and the DFN package may have a rectangular shape. The island 10 has four corners, and thus, upper, lower, left, and right first, second, third, and fourth connection rib portions 201, 202, 203, and 204 are provided at the four corners, respectively. Each of the web 20 portions includes: a bifurcated support corner 21 portion and a bar-shaped connecting rib 22. Optionally, the supporting angle 21 part can be fixed in the edge area of the lead frame structure 01 of the DFN package or the QFN package in a welding or screw mode, one end of the strip-shaped connecting rib 22 part is integrally connected with the base island 10 in the middle square area, and the other end of the connecting rib 22 is integrally connected with the supporting angle 21 in the same way, so that the base island 10 is firmly fixed in the central area of the frame by the force of four corners of the frame, the falling off caused by the follow-up chip installation and welding wire is effectively prevented, and the stability of the lead frame is improved.

In one embodiment, the frame structure 01 further comprises: a lead 30, the lead 30 being located in a peripheral region of the base island 10; the connecting rib 20 equally divides the peripheral area into four areas, and the pins 30 are symmetrically arranged in the four areas relative to the center of the base island 10.

Illustratively, the frame structure includes, in addition to the central region (large pad) of the base island 10 for mounting the chip, an etched region around the periphery of the base island 10, and the etched region around the periphery of the package around the large pad typically has conductive pads, i.e., pins 30, for electrical connection. Four strip-shaped connecting ribs 20 are added between the central area and the peripheral etching area of the base island 10, the connecting ribs can specifically comprise a first connecting rib part 201, a second connecting rib part 202, a third connecting rib part 203 and a fourth connecting rib part 204, the base island 10 can be connected and fixed through the edge outer walls of the peripheral etching area, the pins 30 can be evenly divided into four divided areas, stress generated in the chip packaging process can be directly transmitted to the edge outer wall connecting strips through the connecting ribs 20 without passing through the pin 30 areas, the inner wall of the semiconductor package is extruded by the edge outer wall connecting strips, the connection firmness of the edge outer wall connecting strips and the semiconductor package is further improved, the pins 30 caused in the subsequent chip and wire bonding process are effectively prevented from falling off, and the stability of lead packaging is improved.

In one embodiment, the chips connected to the submount 10 are connected by wire bonds to the leads 30.

Illustratively, frame pins 30 are disposed around the outer periphery of the central region of the base island 10, and chips connected to the base island 10 may be connected to the frame pins 30 by bonding wires, and the chips may be connected to the base island 10 by glue to realize the function of the frame structure. Through the design of the structure, the chip, the bonding wires, the connecting ribs 20 and the pins 30 in the base island 10 area form a whole, the connecting ribs 20 connect the base island 10 area and the pins 30 area into a whole, and when the base island 10 area is subjected to buckling deformation, stress can be transmitted to the edge of the outer wall through the connecting ribs 20 in the base island 10 area, so that the transmission of stress is ensured, and the utilization rate of the base island 10, the chip and the pins 30 is improved.

In one embodiment, the first grooves 221 and the second grooves 222 are disposed in a staggered manner on the connecting rib 20 along a direction perpendicular to the central region; wherein the first groove 221 and the second groove 222 have the same size.

As shown in fig. 2, fig. 2 is a partial enlarged view of a dashed line box in fig. 1, in the process of packaging a chip, a complex internal stress environment is generated due to different shrinkage and expansion coefficients of materials in each process, at this time, the edge of the chip presses the edge of the island 10 region to release stress, and the island 10 region releases the stress to the outer edge, so that the stress acting on the island 10 region is released, and the stress is released to the outer edge and transferred to the semiconductor package connected to the outer wall thereof. By adding four strip-shaped connecting ribs 20 between the central area of the base island 10 and the edge of the outer wall, and arranging two first grooves 221 and second grooves 222 with the same size on the connecting ribs 20 in a staggered manner along the stress release direction, the released stress can be buffered step by step, and meanwhile, the concave grooves with the same size can be balanced better in the connection stability and the stress release.

In one embodiment, the shape of the first groove 221 and the second groove 222 is square or rectangular.

Illustratively, four strip-shaped connecting ribs 20 are added between the central area and the outer wall edge of the base island 10, which may specifically include a first connecting rib portion 201, a second connecting rib portion 202, a third connecting rib portion 203 and a fourth connecting rib portion 204 in fig. 1, and the base island 10 may be connected and fixed by the outer wall of the edge of the peripheral and circumferential etched area. As shown in fig. 2, two square or rectangular first grooves 221 and second grooves 222 are formed on the connecting rib 20 in a staggered manner along the stress release direction, and compared with oval or diamond grooves, the area is large, so that the stress is released more easily, and the occurrence of warping is further avoided.

In one embodiment, the recess depth of the first groove 221 and the second groove 222 is not more than one half of the width of the connecting rib 22.

As shown in fig. 2, two square or rectangular grooves 221 and second grooves 222 with the same or different size are formed on the connecting rib 20 in a staggered manner along the stress releasing direction, and if the recess depth of the grooves exceeds one half of the width of the connecting rib 22, the connecting rib 22 is easy to damage, bending collapse of the region of the base island 10 is easy to cause instability of connecting and fixing the connecting rib 22, so that the opening depth of the first grooves 221 and the second grooves 222 is kept in a range smaller than one half of the width of the connecting rib 22, the occurrence of bending collapse can be reduced, and the stability of fixing the region of the base island 10 is improved.

In one embodiment, the frame structure 01 further comprises: plastic packaging material; the plastic packaging material encapsulates the base island 10, the pins 30 and the connecting ribs 20 into an integral frame.

Illustratively, the elongated islands 10, pins 30 and ribs 20 are arranged in an injection mold according to the position requirements; injecting plastic packaging material in an injection mold, wherein the plastic packaging material wraps the base island 10, the pins 30 and the connecting ribs 20 to form a columnar body; the pillars are cut into sheets, thereby forming a DFN or QFN leadframe. The base island 10, the pins 30 and the connecting ribs 20 are connected into an integral frame by using plastic packaging materials, which is equivalent to embedding the base island 10, the pins 30 and the connecting ribs 20 on the plastic packaging materials, so that the positions and the fixed firmness of the base island 10, the pins 30 and the connecting ribs 20 are ensured, the strength of the lead frame is higher, deformation caused by abnormal production is not easy to occur, the strength and the supporting strength of the pins 30 are also stronger, deformation of the base island 10 or the pins 30 caused by multiple bonding can be avoided, the cost is reduced, and the performance of the frame structure is optimized.

The embodiment of the utility model also provides a lead frame, which comprises a plurality of lead frame structures 01, wherein the lead frame structures 01 are the lead frame structures 01 in any of the above embodiments. The lead frame comprises a plurality of frame structure units with the optimized connecting rib 20 structure, and the connecting ribs 20 are provided with the oppositely staggered grooves, so that the warping stress of the chip can be well buffered, the production efficiency is not affected, the process condition is not changed, the quality of the production efficiency is ensured, and the stability of the chip package is improved.

In the embodiments provided in the present utility model, it should be understood that the disclosed apparatus and method may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, and the division of the modules is merely a logical function division, and there may be additional divisions when actually implemented, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form. The functional modules in the embodiment of the utility model can be integrated together to form a single part, or each module can exist alone, or two or more modules can be integrated to form a single part.

In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

The above description is only an example of the present utility model and is not intended to limit the scope of the present utility model, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. A lead frame structure, the frame structure comprising: the base island and the connecting ribs; the base island is fixed in the central area of the frame structure through connecting ribs;

the connecting rib comprises: a support angle and a connecting rib;

the support angle is fixed at the edge area of the frame structure; one end of the connecting rib is fixedly connected with the base island, and the other end of the connecting rib is fixedly connected with the supporting angle;

the connecting ribs are provided with a first groove and a second groove along the stress releasing direction of the base island; the first grooves and the second grooves are oppositely staggered and are spaced by a preset distance; wherein, the preset distance is smaller than the length of the connecting rib.

2. The frame structure of claim 1, wherein the island stress relief direction is a direction in which a central region of the frame structure is relieved to an edge region.

3. The frame structure of claim 1, wherein the islands are rectangular in shape; the connecting rib comprises: the first rib connecting part, the second rib connecting part, the third rib connecting part and the fourth rib connecting part;

the first rib connecting part, the second rib connecting part, the third rib connecting part and the fourth rib connecting part are positioned at four corners of the base island; the base island is fixed in the central area of the frame structure through the first connecting rib part, the second connecting rib part, the third connecting rib part and the fourth connecting rib part.

4. A frame structure according to claim 3, wherein the frame structure further comprises: the pins are positioned in the peripheral area of the base island;

the connecting ribs divide the peripheral area into four areas uniformly, and the pins are symmetrically arranged in the four areas relative to the center of the base island.

5. The frame structure of claim 4, wherein the die attached to the submount is connected to the leads by bonding wires.

6. The frame structure of claim 1, wherein the first and second grooves are oppositely staggered on the web in a direction perpendicular to the central region; the first groove and the second groove are the same in size.

7. The frame structure of claim 1, wherein the first and second grooves are square or rectangular in shape.

8. The frame structure of claim 1, wherein the first and second grooves have a recess depth of no more than one half the width of the connecting rib.

9. The frame structure of claim 1, wherein the frame structure further comprises: plastic packaging material; and the plastic packaging material packages the base island, the pins and the connecting ribs into an integral frame.

10. A lead frame, characterized in that the lead frame comprises a plurality of lead frame structures, the lead frame structures being as claimed in any one of claims 1-9.