CN210805765U

CN210805765U - Novel SMD packaging structure's lead frame

Info

Publication number: CN210805765U
Application number: CN201922405671.7U
Authority: CN
Inventors: 吴育洪; 郑晓颖; 郑思海
Original assignee: Guangdong Xianjie Electronic Co ltd
Current assignee: Anhui Xianjie Electronics Co.,Ltd.
Priority date: 2019-12-28
Filing date: 2019-12-28
Publication date: 2020-06-19
Anticipated expiration: 2029-12-28

Abstract

The utility model provides a lead frame of a novel SMD packaging structure, which is characterized in that the whole lead frame comprises a core-carrying structural unit, pins, mechanical positioning holes, bearing ribs and transverse connecting ribs; an L-shaped first base island and an inverted L-shaped second base island are distributed on the core-carrying structural unit, and the first base island and the second base island are complementarily meshed; through improving traditional single row array into multirow array lead frame, this product can satisfy and compatible microelectronics product packaging manufacturing's high reliability, miniaturization, convenient, promotes semiconductor industry packaging process level, promotes encapsulation equipment's renewal iteration, makes to paste dress type components and parts and possesses the multiple function characteristic, and the product possesses high standardization, high reliability, high accuracy, high density, high yield quantization and multi-functionalization, and manufacturing cycle shortens greatly.

Description

Novel SMD packaging structure's lead frame

Technical Field

The utility model relates to semiconductor electronic components's manufacturing technical field, concretely relates to novel SMD packaging structure's lead frame.

Background

Semiconductor integrated circuit devices are known as "industrial" devices, but in general, users need not only fully functional bare chips, but also lead frames for protection and support, which have multiple functions such as mechanical support, electrical connection, physical protection, external field shielding, stress relaxation, heat dissipation, moisture protection, size transition, normalization, and standardization; the lead frame is a key structural member for realizing the electrical connection between the leading-out end of the internal circuit of the chip and the external lead by means of the bonding lead to form an electrical loop, plays a role of a bridge connected with an external lead, needs to be used in most semiconductor chips and is an important basic material in the semiconductor industry.

The lead frame is produced along with the production of semiconductor electronic components such as integrated circuits, develops along with the development of semiconductor technology, along with the rapid improvement of the integrated level of the integrated circuits and the development of high reliability, miniaturization and surface mounting, higher requirements are put forward on the design, processing and quality of the lead frame, the new product updating and new process of the lead frame come out, the development of the semiconductor industry is promoted, and certain influence is caused on the traditional lead frame correspondingly:

(1) most lead frames of the traditional SMD packaging structure are distributed in a single-row array manner, the manufacturing cost of the lead frames is high, the manufacturing frame of the lead frames in the single-row array manner is too long, and the occupied material consumption is large, so that the standardization difficulty of the mold design is high, the mold design is completed by dividing the lead frames into a plurality of mold cavities, the product molding cannot be synchronously completed, and the lead frames cannot be effectively applied to a material transmission system of a high-speed die bonder and a wire bonder, so that the occupancy rate of the quantity of equipment is high, and unnecessary energy waste is caused;

(2) with the improvement of the processing level and the updating iteration of processing equipment, the lead frame of the SMD packaging structure gradually develops towards the directions of high precision, high density and high yield, the single-row array lead frame is gradually eliminated, the service life is short, the mold standardization degree is low, the manufacturing period is long, and the commercial efficiency requirement cannot be met.

Disclosure of Invention

The utility model discloses an overcome that the lead frame precision that produces in the current like product manufacturing process is poor, low density, output is low, paster type components and parts outer pin when the encapsulation lacks defect and not enough such as become more meticulous, outer pin overlength, too wide, too thick, provide one kind to the society and accord with design mould standardization, production efficiency and raw and other materials high-usage, product encapsulation is of high quality, long service life, towards the microelectronics encapsulation lead frame of high accuracy, high density, high yield direction development.

In order to solve the above problem, the preferred embodiment of the present invention is a lead frame of a novel SMD package structure, which is characterized in that: the lead frame integrally comprises a core carrying structure unit, pins, mechanical positioning holes, bearing ribs and transverse connecting ribs; the bearing core structure unit comprises a bearing core structure unit and is characterized in that L-shaped first base islands and inverted L-shaped second base islands are distributed on the bearing core structure unit, the first base islands and the second base islands are in complementary meshing, the first base islands and the second base islands are respectively connected with pins, the bearing ribs, the bearing core structure unit and the pins are horizontally arranged in a collinear manner, mechanical positioning holes for transmission are arranged on the transverse connecting ribs, the mechanical positioning holes are aligned to the bearing ribs, and the pins and the bearing ribs are connected to the transverse connecting ribs.

Preferably, the first base island and the second base island on the core-carrying structure unit are respectively provided with an injection molding via hole, the diameter of the via hole is smaller than the width of the first base island and the width of the second base island, and the via holes are symmetrically distributed.

Furthermore, the surfaces of the first base island and the second base island are plated with an anti-oxidation layer, the anti-oxidation layer is a silver plating layer with excellent conductivity, and the thickness of the silver plating layer is 15 +/-5 microns, so that the conductivity of the chip bonded on the first base island and the second base island is enhanced.

Furthermore, the core carrying structural units are vertically distributed in 4 rows in an array manner by adopting an etching process or a punching process, 5 core carrying structural units are horizontally and collinearly distributed in each row to form an array unit structure, the array unit structure can be transversely arrayed and expanded to at least 2 groups or more, the core carrying structural units are formed by adopting an etching or punching material which is copper-based, aluminum-based or iron-nickel-based alloy, the thickness is 0.152mm, and the hardness performance of the material is below 200 HV.

Furthermore, the width of the pin is smaller than the widths of the first base island and the second base island on the core carrying structural unit.

Furthermore, the width of the transverse connecting rib is equal to the width of the pin.

Furthermore, the diameter of the mechanical positioning hole is equal to the width of the bearing rib.

Furthermore, the number of the mechanical positioning holes arranged on the transverse connecting ribs is equal to the number of the bearing ribs.

Compared with the prior art, the utility model provides a pair of novel SMD packaging structure's lead frame beneficial effect is that, the utility model discloses improve into multirow array lead frame to traditional single row array, can satisfy through this product with compatible microelectronics product packaging manufacturing's high reliability, miniaturization, convenient, promote semiconductor industry encapsulation process level, promote encapsulation equipment's update iteration, make to paste dress type components and parts and possess the multifunctional characteristic, the product possesses high standardization, high reliability, high accuracy, high density, high yield quantization and multi-functional, manufacturing cycle shortens greatly.

Drawings

Fig. 1 is a schematic diagram of the product structure of the present invention.

Fig. 2 is a schematic diagram of the product expansion of the present invention.

Detailed Description

The present invention is further explained in detail with reference to the following examples, which are only for explanation and are not intended to limit the present invention.

As shown in fig. 1 to fig. 2, an embodiment of the present invention provides a lead frame of a novel SMD package structure, the lead frame integrally includes a core-carrying structure unit 101, pins 102, mechanical positioning holes 103, a bearing rib 104 and a transverse connecting rib 105; the core carrying structure unit 101 is distributed with an L-shaped first base island 106 and an inverted L-shaped second base island 107, the L-shaped first base island 106 and the inverted L-shaped second base island 107 are complementarily meshed, the tail ends of the first base island 106 and the second base island 107 are respectively connected with the pins 102, the bearing ribs 104, the core carrying structure unit 101 and the pins 102 are arranged in the same horizontal collinear mode, the transverse connecting ribs 105 are provided with mechanical positioning holes 103 for transmission, the mechanical positioning holes 103 are aligned to the bearing ribs 104, and the pins 102 and the bearing ribs 104 are connected to the transverse connecting ribs 105.

As shown in fig. 1 to 2, in the embodiment, the first base island 106 and the second base island 107 distributed on the core-carrying structural unit 101 are respectively provided with an injection molding via hole 108, the diameter of the via hole 108 is smaller than the width of the first base island 106 and the second base island 107, the via holes 108 are symmetrically distributed, and the collapse or displacement of the bonding alloy wire caused by the overstress can be effectively alleviated in the plastic package process of the product.

As shown in fig. 2, in the present embodiment, the first base island 106 and the second base island 107 are plated with an anti-oxidation layer, the anti-oxidation layer is a silver-plated layer with excellent conductivity, and the thickness of the silver-plated layer is 15 μm, so as to enhance the conductivity of the chip adhered to the first base island 106 and the second base island 107, improve the signal transmission between the chip and the external connection device, and reduce the signal delay and hysteresis.

As shown in fig. 1 to 2, in the present embodiment, the core-carrying structural units 101 are vertically distributed in 4 rows in an array manner by using an etching process, 5 core-carrying structural units 101 are horizontally and collinearly distributed in each row to form an array unit structure, the horizontal array is extended to 5 groups of array unit structures, the etching material used is a copper-based material with excellent conductivity, the overall thickness of the lead frame is 0.152mm, and the hardness of the material is below 200 HV.

As shown in fig. 2, in this embodiment, the width of the pin 102 is smaller than the widths of the first base island 106 and the second base island 107 on the core-loading structure unit 101, so as to effectively prevent the occurrence of air holes due to the surface flash and low air tightness of the product appearance caused by the excessively large width of the pin 102 during the product injection molding process.

As shown in fig. 2, in the embodiment, the width of the transverse rib 105 is equal to the width of the lead 102, so that the lead 102 can be effectively and tightly connected with the transverse rib 105, and the mechanical deformation of the lead frame caused by external stress is prevented.

As shown in fig. 2, the diameter of the mechanical positioning hole 103 is equal to the width of the carrier bar 104, and the same width effectively ensures that the hooking device for transmission does not collide with the lead frame to cause displacement or dislocation during transmission, and improves the transmission sensing recognition capability.

As shown in fig. 2, the transverse connecting rib 105 is provided with a plurality of mechanical positioning holes 103 equal to the number of the bearing ribs 104, and when the transverse array is expanded to 5 groups of array unit structures, 4 mechanical positioning holes 103 are provided for conveying materials and 4 bearing ribs 104 are provided for supporting the whole body.

The embodiment of the utility model provides a novel SMD packaging structure's lead frame's beneficial effect is that compare in prior art, the certain array of accessible expands to 5 groups or 5 unit structures more than organizing, sets up the via hole on the base island and has effectively stopped the product plastic envelope process and lead to overflow glue and gas pocket, has ensured that the base island avoids bending deformation at plastic envelope matched die pressure, has satisfied the demand of market to SMD packaging structure pluralism.

Obviously, the above embodiments of the present invention are only examples for clearly illustrating the application of the present invention, and are not intended to limit the embodiments of the present invention; it will be apparent to those skilled in the art that other variations and modifications may be made in the foregoing description, and it is not necessary or exhaustive for all embodiments to be present; any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A lead frame of a novel SMD packaging structure is characterized in that the whole lead frame comprises a core carrying structure unit, pins, mechanical positioning holes, carrying ribs and transverse connecting ribs; an L-shaped first base island and an inverted L-shaped second base island are distributed on the core-carrying structural unit, and the first base island and the second base island are complementarily meshed; the first base island and the second base island are respectively connected with the pins, the bearing ribs, the core carrying structure units and the pins are horizontally arranged in a collinear manner, the transverse connecting ribs are provided with mechanical positioning holes for transmission, the mechanical positioning holes are aligned to the bearing ribs, and the pins and the bearing ribs are connected to the transverse connecting ribs.

2. The lead frame of the novel SMD package structure according to claim 1, wherein said first and second islands of said carrier structure unit are respectively formed with an injection via hole, the diameter of said via hole is smaller than the width of said first and second islands, and said via holes are symmetrically distributed.

3. The lead frame of a novel SMD package structure according to claim 1 or 2, wherein said first and second base islands are plated with an anti-oxidation layer, and said anti-oxidation layer is a silver plated layer with excellent conductivity, and the thickness of the silver plated layer is 15 ± 5 μm, so as to enhance the conductivity of the chip adhered on said first and second base islands.

4. The lead frame of a novel SMD packaging structure according to claim 1, characterized in that said carrier structure units are vertically arranged in 4 rows by etching or punching, each row of said carrier structure units are horizontally arranged in a collinear manner and have 5 carrier structure units, forming an array unit structure, and can be transversely arranged and expanded to at least 2 groups or more, and said array unit structure is made of copper-based, aluminum-based or iron-nickel-based alloy by etching or punching, and has a thickness of 0.152mm and a hardness of less than 200 HV.

5. The lead frame of a novel SMD package structure according to claim 1, wherein said lead width is smaller than the width of said first and second base islands on said chip carrier structure unit.

6. The lead frame of a novel SMD package structure according to claim 1, characterized in that said transverse tie bar width is equal to said lead width.

7. The lead frame of the novel SMD package structure of claim 1, wherein said mechanical positioning hole diameter is equal to said carrier bar width.

8. The lead frame of a novel SMD package structure according to claim 1, wherein said transverse connecting rib has a number of mechanical positioning holes equal to the number of said carrier ribs.