Lead frame capable of increasing strength of multiple circles of pins
By staggering the inner and outer ring pins and adding solid ribs through semi-etching, the bridging and deformation problems of multi-ring pin packaged products are solved, improving the strength and stability of the lead frame and enhancing product quality and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU SILICON INTEGRITY SEMICON TECH CO LTD
- Filing Date
- 2025-05-23
- Publication Date
- 2026-05-05
AI Technical Summary
In existing designs, multi-pin packaged products have high requirements for metal clearance, are prone to bridging, and suffer from frame deformation and insufficient strength, which affects product quality and reliability.
By arranging the inner and outer ring pins in an alternating manner and performing semi-etching at the connection points between the inner and outer ring pins and the unit ribs, solid ribs are added to form a structure that is wider inside and narrower outside, and narrower inside and wider outside, thereby increasing the pin gap and supporting the pins to improve strength.
It enhances the strength and stability of the lead frame, reduces the risk of deformation during packaging, transportation and manufacturing, improves product reliability and reduces the defect rate.
Smart Images
Figure CN224205648U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor packaging technology, and more specifically to a lead frame for increasing the strength of multi-turn pins. Background Technology
[0002] With the continuous development of packaging technology integration, the size of packaged products is getting larger and larger, and the pin arrangement is denser. To increase the integration to meet different packaging needs, a double-ring pin arrangement design has emerged.
[0003] Existing designs, to accommodate more pins, refine the width of the pin roots and extend them towards the central base island of the package to meet the requirements of product bonding wires. However, this type of product design places higher demands on the gaps between metals; otherwise, there is a risk of bridging. Furthermore, such products have exhibited issues such as frame deformation and insufficient strength, leading to abnormalities in product quality and reliability. Summary of the Invention
[0004] To address the aforementioned issues, this invention provides a lead frame that increases the strength of multi-turn pins. The inner and outer turns of pins are arranged in an alternating pattern, and the inner extension pins are optimized to increase the strength of the lead frame, reduce the risk of deformation, ensure the gap between pins, and improve product quality.
[0005] According to one aspect of the present invention, a lead frame for increasing the strength of multi-turn pins is provided, comprising multiple lead frame units arranged in an array, with unit connecting ribs between each lead frame unit. Each lead frame unit includes a base island, inner ring pins, and outer ring pins. The four corners of the base island are connected to the unit connecting ribs through the base island connecting ribs. The inner ring pins are arranged in an array in the inner ring near the base island, and the outer ring pins are arranged in an array in the outer ring near the unit connecting ribs. The inner ring pins and outer ring pins are arranged alternately and sequentially. The outer ring pins are solid pins and are close to the unit connecting ribs. The front end of the outer ring pin has a narrowed inner extension pin one, the width of which is smaller than the width of the outer ring pin. The inner ring pin is a solid pin. The root of the inner ring pin has a narrowed inner extension pin two, the width of which is smaller than the width of the inner ring pin. The inner extension pin two extends to the unit connecting ribs. Therefore, the inner and outer ring pins are arranged in an alternating pattern, with inner and outer rings. Inner ring pin one separates the inner ring pins, and inner ring pin two separates the outer ring pins. Inner ring pin one and inner ring pin two are narrower than the outer and inner ring pins, forming a structure that is wider inside and narrower outside, and an outer ring pin that is narrower inside and wider outside. This increases the gap between the pins. Inner ring pin one supports the front end of the outer ring pin and increases the strength between the inner ring pins. Inner ring pin two supports the root of the inner ring pin and increases the strength between the outer ring pins, thereby reducing the risk of deformation during packaging, transportation, and manufacturing.
[0006] In some embodiments, the inner pin 1 is partially etched to form a recessed structure. The inner pin 1 has a protruding solid rib 1 that extends inward to the top of the vertical portion of the inner pin 1 and outward to the front end of the outer pin. The top surface of the solid rib 1 does not protrude from the surface of the outer pin. Thus, the partial etching of the inner pin 1 halves its thickness, increases the upper gap between the inner pins, reduces the risk of bridging, and the addition of the solid rib 1 to the inner pin 1 supports the inner pin 1 itself at the front end of the outer pin, increasing the strength of the lead frame.
[0007] In some embodiments, the second inner protruding pin is partially etched to form a recessed structure. The second inner protruding pin has a protruding solid rib, which extends inward to the root of the inner ring pin and outward to the unit connecting rib. The top surface of the solid rib does not protrude from the surface of the inner ring pin. Thus, the partial etching of the second inner protruding pin halves its thickness, increases the upper gap between the outer ring pins, reduces the risk of bridging, and at the same time, the addition of the solid rib on the second inner protruding pin supports the second inner protruding pin itself, increasing its strength.
[0008] In some implementations, the unit connecting ribs are partially etched to form a recessed structure. The unit connecting ribs have a protruding solid rib three, which intersects with solid rib two. The top surface of solid rib three does not protrude beyond the surface of the outer ring pin. Thus, the partially etched unit connecting ribs facilitate the cutting of the lead frame after packaging, and the solid rib three can support the unit connecting ribs, increasing the strength of the lead frame.
[0009] In some implementations, the height of solid rib one, solid rib two, and solid rib three is 1 / 4 of the lead frame thickness. Thus, the semi-etched inner protrusion pin one, inner protrusion pin two, and unit connecting rib make the main body half the thickness of the lead frame, with 1 / 4 of the lead frame thickness retained in the middle as solid rib one, solid rib two, and solid rib three. This design ensures the solid ribs are not exposed, increasing the strength of the lead frame without affecting the product's appearance. After each lead frame unit is cut, solid rib three is removed simultaneously with the unit connecting rib.
[0010] In some embodiments, the width of solid rib one, solid rib two, and solid rib three is 0.05 mm, and the top surface of solid rib one, solid rib two, and solid rib three is at least 0.03 mm away from the surface of the lead frame. Thus, current manufacturing processes can meet this dimensional requirement and ensure that the solid ribs are not exposed.
[0011] In some implementations, the half-etch width of the unit rib at the outer ring pin connection is wider than the width of the unit rib, and the half-etch width of the unit rib at the outer ring pin connection is narrower than the width of the cut line between each lead frame unit. This ensures that the unit rib is completely half-etched, and that the half-etched portion of the unit rib can be completely removed after the lead frame units are separated.
[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: The lead frame structure provided by this utility model is novel. The front end of the outer ring pin has a narrowed inner extension pin one, and the inner ring pin and the unit connecting rib have a narrowed inner extension pin two. Each pin is separated by the inner extension pin, forming an inner ring pin that is wider inside and narrower outside, and an outer ring pin that is narrower inside and wider outside. The vertical parts of the inner extension pin one and the inner extension pin two are partially etched and have a solid rib with 1 / 4 of the lead frame thickness added, which increases the upper gap between each pin and supports the inner extension pin. In addition, the unit connecting rib is also partially etched and has a solid rib with 1 / 4 of the lead frame thickness added, so as to increase the strength and stability of the lead frame, reduce the deformation risk during packaging, transportation and manufacturing, improve product reliability and reduce the defect rate in production. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of a lead frame for increasing the strength of multi-turn leads according to this utility model before cutting;
[0014] Figure 2 This is a schematic diagram of the cut lead frame structure;
[0015] Figure 3 yes Figure 1 In the AA cross-sectional view, H represents the lead frame thickness, H1 represents the etching depth (H1 is 1 / 2H), and H2 represents the solid rib height (H2 is 1 / 4H).
[0016] Figure 4 yes Figure 1 Enlarged view of section B in the middle. Detailed Implementation
[0017] The present invention will be further described below with reference to specific embodiments.
[0018] like Figure 1 and 2As shown, a lead frame for increasing the strength of multi-turn pins according to one embodiment of the present invention includes multiple lead frame units 10 arranged in an array. Unit connecting ribs 3 are provided between each lead frame unit 10. Each lead frame unit 10 includes a base island 1, inner ring pins 4, and outer ring pins 5. The four corners of the base island 1 are connected to the unit connecting ribs 3 via base island connecting ribs 2. The inner ring pins 4 are arranged in an array near the inner ring of the base island 1, and the outer ring pins 5 are arranged in an array near the outer ring of the unit connecting ribs 3. The inner ring pins 4 and outer ring pins 5 are arranged alternately and sequentially. The technical solution provided by this application can support more complex packaging designs and is not limited to a single inner ring pin and a single outer ring pin structure; it can be a multi-turn pin design. To better illustrate the technical solution of this application, the lead frame provided in this embodiment is a double-turn pin design with one inner ring pin and one outer ring pin.
[0019] The outer ring pin 5 is a solid pin, and its root is connected to the unit connecting rib 3. The front end of the outer ring pin 5 has a narrowed inner extension pin 1 51, which extends towards the base island 1. The width of the inner extension pin 1 51 is smaller than the width of the outer ring pin 5, except for the width of the inner extension pins of the outer ring pin 5 at the four corners of the lead frame. The inner ring pin 4 is a solid pin, and its root has a narrowed inner extension pin 2 41. The front end of the inner ring pin 4 has a narrowed inner extension pin 3 43. The widths of the inner extension pin 2 41 and the inner extension pin 3 43 are smaller than the width of the inner ring pin 4. The inner extension pin 2 41 extends to the unit connecting rib 3, and the front end of the inner extension pin 3 43 extends towards the base island 1.
[0020] The inner ring pins 4 and outer ring pins 5 are arranged in an alternating pattern, with inner and outer rings. Inner extension pin 1 51 separates the inner ring pins 4, and inner extension pin 2 41 separates the outer ring pins 5. The widths of inner extension pins 1 51 and 2 41 are narrower than those of the outer ring pins 5 and inner ring pins 4. The section from the inner ring pin 4 to the unit connecting rib 3 forms a structure with a wider inner ring and a narrower outer ring. The section from the outer ring pin 5 to the vertical portion of the front inner extension pin 1 51 to the unit connecting rib 3 forms a structure with a narrower inner ring and a wider outer ring, increasing the gaps between the pins. Inner extension pin 1 51 supports the front end of the outer ring pin 5 and increases the strength between the inner ring pins 4, while inner extension pin 2 41 supports the root of the inner ring pin 4 and increases the strength between the outer ring pins 5.
[0021] like Figure 1 and 3As shown, the unit connecting rib 3, the inner extension pin 2 41, and the vertical portion of the inner extension pin 1 51 perpendicular to the front end of the outer ring pin 5 are partially etched. Relative to the thickness of the lead frame, the partially etched portion forms a recessed structure. The partially etched portion has protruding solid ribs 31, 42, and 52. Solid rib 1 52 extends inwards to the top of the vertical portion of the inner extension pin 1 51, and inwards to the front end of the outer ring pin 5. Solid rib 2 42 extends inwards to the root of the inner ring pin 4, and inwards to the unit connecting rib 3, where solid rib 2 42 intersects with solid rib 31.
[0022] Semi-etching inner extension pin 1 51 and inner extension pin 2 41 halves their thickness, increasing the upper gap between inner ring pins 4 and outer ring pins 5, reducing bridging risk. At the same time, adding solid ribs 1 52 and 2 42 to inner extension pin 1 51 and inner extension pin 2 41 can support the inner extension pin 1 51 itself at the front end of outer ring pin 5 and support the inner extension pin 2 41 itself, increasing the strength of the lead frame.
[0023] The semi-etched unit connecting rib 3 reduces the thickness of the unit connecting rib 3, which is beneficial for cutting the lead frame after packaging. The solid rib 31 can support the unit connecting rib 3 and increase the strength of the lead frame.
[0024] like Figure 3 As shown, the height of solid rib 1 52, solid rib 2 42, and solid rib 3 31 is 1 / 4 of the thickness of the lead frame. During manufacturing, the inner extension pin 1 51, inner extension pin 2 41, and unit connecting rib 3 are semi-etched to make the main body half the thickness of the lead frame. 1 / 4 of the lead frame thickness is retained in the middle as solid rib 1 52, solid rib 2 42, and solid rib 3 31. This design ensures that the solid ribs are not exposed, which increases the strength of the lead frame without affecting the appearance of the product. After each lead frame unit 10 is cut, solid rib 31 will be cut off simultaneously with the unit connecting rib 3.
[0025] Specifically, in this embodiment, the width of solid rib 1 52, solid rib 2 42, and solid rib 31 is 0.05 mm, and the top surface of solid rib 1 52, solid rib 2 42, and solid rib 31 is at least 0.03 mm away from the surface of the lead frame. Current manufacturing processes can meet this dimensional requirement and ensure that the solid ribs are not exposed.
[0026] like Figure 3 and 4As shown, before being cut into individual lead frame units 10, each lead frame unit 10 is distributed in a rectangular array, symmetrically arranged relative to the unit connecting rib 3. The outer ring pins 5 and inner ring pins 41 are symmetrically distributed on both sides of the unit connecting rib 3. The half-etch width W2 at the connection point is wider than the width W1 of the unit connecting rib 3, while the half-etch width W2 at the connection point is narrower than the width W3 of the cutting line between each lead frame unit 10. This ensures that the unit connecting rib 3 is completely half-etched, and that the half-etched portion of the unit connecting rib 3 can be completely removed after the lead frame units 10 are separated.
[0027] The lead frame structure provided by this utility model is novel. The front end of the outer ring pin 5 has a narrowed inner extension pin 51, and the inner ring pin 4 and the unit connecting rib 3 have a narrowed inner extension pin 41. Each pin is separated by the inner extension pin. The vertical part of the inner extension pin 51 and the inner extension pin 41 is partially etched and has a solid rib with 1 / 4 of the lead frame thickness. This increases the upper gap between each pin and supports the inner extension pin. In addition, the unit connecting rib 3 is also partially etched and has a solid rib with 1 / 4 of the lead frame thickness to increase the strength and stability of the lead frame, reduce the risk of deformation during packaging, transportation and manufacturing, improve product reliability and reduce the defect rate in production.
[0028] The above descriptions are merely some embodiments of this utility model. It should be noted that those skilled in the art can make other modifications and improvements without departing from the inventive concept of this utility model, and these all fall within the protection scope of this utility model.
Claims
1. A lead frame for increasing the strength of multi-turn pins, comprising multiple lead frame units (10) arranged in an array, wherein unit connecting ribs (3) are provided between each lead frame unit (10), each lead frame unit (10) comprising a base island (1), inner ring pins (4) and outer ring pins (5), wherein the four corners of the base island (1) are connected to the unit connecting ribs (3) through base island connecting ribs (2), the inner ring pins (4) are arranged in an array in the inner ring near the base island (1), and the outer ring pins (5) are arranged in an array in the outer ring near the unit connecting ribs (3), wherein the inner ring pins (4) and the outer ring pins (5) are arranged alternately at intervals, characterized in that, The outer ring foot (5) is a solid foot and is close to the unit connecting rib (3). The front end of the outer ring foot (5) has a narrowed inner extension foot one (51). The width of the inner extension foot one (51) is smaller than the width of the outer ring foot (5). The inner ring foot (4) is a solid foot. The root of the inner ring foot (4) has a narrowed inner extension foot two (41). The width of the inner extension foot two (41) is smaller than the width of the inner ring foot (4). The inner extension foot two (41) extends to the unit connecting rib (3).
2. The lead frame for increasing the strength of multi-turn pins according to claim 1, characterized in that, The inner protruding pin (51) is partially etched and has a protruding solid rib (52) extending inward to the top of the vertical portion of the inner protruding pin (51) and extending outward to the front end of the outer ring pin (5). The top surface of the solid rib (52) does not protrude from the surface of the outer ring pin (5).
3. The lead frame for increasing the strength of multi-turn pins according to claim 2, characterized in that, The inner extension pin 2 (41) is partially etched and the inner extension pin 2 (41) has a protruding solid rib 2 (42) extending inward to the root of the inner ring pin (4) and extending outward to the unit connecting rib (3). The top surface of the solid rib 2 (42) does not protrude from the surface of the inner ring pin (4).
4. The lead frame for increasing the strength of multi-turn pins according to claim 3, characterized in that, The unit connecting rib (3) is partially etched and the unit connecting rib (3) has a protruding solid rib three (31), the solid rib two (42) intersects with the solid rib three (31), and the top surface of the solid rib three (31) does not protrude from the surface of the outer ring tube foot (5).
5. The lead frame for increasing the strength of multi-turn pins according to claim 4, characterized in that, The height of solid rib one (52), solid rib two (42) and solid rib three (31) is 1 / 4 of the thickness of the lead frame.
6. The lead frame for increasing the strength of multi-turn pins according to claim 5, characterized in that, The width of the first solid rib (52), the second solid rib (42) and the third solid rib (31) is 0.05 mm, and the top surface of the first solid rib (52), the second solid rib (42) and the third solid rib (31) is at least 0.03 mm away from the surface of the lead frame.
7. The lead frame for increasing the strength of multi-turn pins according to claim 4, characterized in that, The half-etch width of the unit connecting rib (3) at the connection of the outer ring pin (5) is wider than the width of the unit connecting rib (3), and the half-etch width of the unit connecting rib (3) at the connection of the outer ring pin (5) is narrower than the width of the cutting line between each lead frame unit.