Nail rack structure and semiconductor structure

Abstract

Embodiments of the present application provide a pin grid array structure, comprising: a package lead frame; and a moisture barrier layer disposed on an upper surface of the package lead frame and covering an intersection of a package compound and the lead frame of the package lead frame. The purpose of the present application is to provide a pin grid array structure and a semiconductor structure to improve yield.

Description

Technical Field

[0001] Embodiments of the present invention relate to nail frame structures and semiconductor structures. Background Technology

[0002] Optical sensor products, such as Vertical-Cavity Surface-Emitting Lasers (VCSELs), typically have small package sizes. Therefore, they can be mounted on pre-mold lead frames using molded plastic, replacing traditional metal canisters and effectively reducing costs. VCSELs are affected by the temperature and humidity within the package space, requiring the package to be waterproof. However, the bonding strength between the copper lead frame sidewalls and the molding compound is not strong enough. Furthermore, during various reliability tests, the mismatch in the coefficients of thermal expansion (CTE) between the lead frame and the molding compound can lead to delamination. Moisture from the environment can then seep into the package structure from the lower end of the lead frame along the delamination, affecting the product's temperature and humidity, causing discrepancies in sensor readings. Moisture can also affect the light emission angle and efficiency of optical products, leading to overall product malfunction. Summary of the Invention

[0003] In view of the problems existing in related technologies, the purpose of this invention is to provide a nail holder structure and a semiconductor structure to improve their yield.

[0004] To achieve the above objectives, embodiments of the present invention provide a nail holder structure, including: an encapsulated lead frame; and a moisture barrier layer disposed on the upper surface of the encapsulated lead frame and covering the junction between the encapsulation compound of the encapsulated lead frame and the lead frame.

[0005] In some embodiments, the encapsulated leadframe is formed by coating the leadframe with an encapsulating compound.

[0006] In some embodiments, the upper surface of the encapsulated compound and the upper surface of the lead frame are coplanar.

[0007] In some embodiments, the moisture barrier layer contacts both the encapsulation compound and the lead frame.

[0008] In some embodiments, the lower surface of the moisture barrier layer is coplanar with the upper surface of the encapsulation compound and the upper surface of the lead frame.

[0009] In some embodiments, the moisture barrier layer is an adhesive material or a membrane material.

[0010] In some embodiments, the moisture barrier layer is a liquid adhesive material, which is formed on the encapsulation lead frame by printing.

[0011] In some embodiments, the moisture barrier layer further fills the recesses at the junction of the encapsulation compound and the lead frame.

[0012] In some embodiments, the moisture barrier layer is a solid membrane material, which is formed on the encapsulation lead frame by molding.

[0013] In some embodiments, the encapsulation compound has a different coefficient of thermal expansion than the lead frame.

[0014] In some embodiments, an air gap is formed between the encapsulation compound and the lead frame, and a moisture barrier layer seals the air gap.

[0015] Embodiments of this application provide a semiconductor packaging structure, including: a packaging lead frame; a moisture barrier layer disposed on the upper surface of the packaging lead frame and covering the junction of the packaging compound and the lead frame; a frame structure and a lens supported by the frame structure, forming a cavity with the packaging lead frame, wherein a chip is located in the cavity and electrically connected to the packaging lead frame.

[0016] In some embodiments, no moisture barrier layer is provided between the chip and the package lead frame.

[0017] In some embodiments, a moisture barrier layer is disposed on the upper surface of the packaging lead frame surrounding the chip.

[0018] In some embodiments, the lens is glass.

[0019] In some embodiments, the chip is also electrically connected to the package lead frame via leads.

[0020] In some embodiments, no moisture barrier layer is provided at the location where the lead wire contacts the package lead frame.

[0021] In some embodiments, light passes through a lens and shines onto the chip.

[0022] In some embodiments, the lens is attached to the inner surface of the frame structure.

[0023] In some embodiments, a moisture barrier layer is provided between the frame structure and the encapsulation lead frame. Attached Figure Description

[0024] The various aspects of the invention will be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industrial practice, the components are not drawn to scale. In fact, for clarity of discussion, the dimensions of the components may be arbitrarily increased or decreased.

[0025] Figure 1 An image showing the structure of the prior art is provided.

[0026] Figures 2 to 4 The diagram shows a schematic diagram and image of the nail holder structure and semiconductor structure according to embodiments of this application. Detailed Implementation

[0027] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0028] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0029] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate small variations. When used in conjunction with an event or situation, the terms may refer to examples in which the event or situation occurred precisely and examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the terms may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, if the difference between two values ​​is less than or equal to ±10% of the average of the values ​​(e.g., less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%), then the two values ​​can be considered "substantially" the same.

[0030] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0031] Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format in this document. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only the numerical values ​​explicitly specified as range limits, but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0032] Furthermore, for ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0033] Figure 1 The image shows the prior art. The current technical bottleneck is that the bonding force between the sidewall of the lead frame 10 and the encapsulation compound (CPD) 12 is not strong enough. In addition, during various reliability tests of the packaged product, the CTE of the encapsulation compound 12 and the lead frame 10 are different, which causes the encapsulation compound 12 and the sidewall of the lead frame 10 to delaminate 14.

[0034] See Figure 2 Embodiments of the present invention provide a pin holder structure 20, including: an encapsulated lead frame 22; and a moisture barrier layer 24 disposed on the upper surface of the encapsulated lead frame 22 and covering the interface between the encapsulation compound 12 of the encapsulated lead frame 22 and the lead frame 10. In some embodiments, the encapsulated lead frame 22 is formed by the encapsulation compound 12 covering the lead frame 10. In some embodiments, the upper surface of the encapsulation compound 12 and the upper surface of the lead frame 10 are coplanar. In some embodiments, the moisture barrier layer 24 simultaneously contacts the encapsulation compound 12 and the lead frame 10. In some embodiments, the lower surface of the moisture barrier layer 24 is coplanar with the upper surface of the encapsulation compound 12 and the upper surface of the lead frame 10.

[0035] In some embodiments, the moisture barrier layer 24 is an adhesive material or a film material. In some embodiments, the moisture barrier layer 24 is a liquid adhesive material, and the moisture barrier layer 24 is formed on the encapsulation lead frame 22 by printing. In some embodiments, the moisture barrier layer 24 further fills the recesses at the interface between the encapsulation compound 12 and the lead frame 10. In some embodiments, the moisture barrier layer 24 is a solid film material, and the moisture barrier layer 24 is formed on the encapsulation lead frame 22 by molding.

[0036] In some embodiments, the encapsulation compound 12 and the lead frame 10 have different coefficients of thermal expansion. In some embodiments, an air gap is formed between the encapsulation compound 12 and the lead frame, and the moisture barrier layer 24 seals the air gap.

[0037] See Figure 3The embodiments of this application provide a semiconductor packaging structure 30, including: a packaging lead frame 22; a moisture barrier layer 24 disposed on the upper surface of the packaging lead frame 22 and covering the junction of the packaging compound 12 and the lead frame 10 of the packaging lead frame 22; a frame structure 32 and a lens 34 supported by the frame structure 32, which together with the packaging lead frame form a cavity 36, and a chip 38 is located in the cavity 36 and electrically connected to the packaging lead frame 22.

[0038] In some embodiments, no moisture barrier layer 24 is provided between the chip 38 and the package lead frame 22. In some embodiments, the moisture barrier layer 24 is provided on the upper surface of the package lead frame 22 surrounding the chip 38. In some embodiments, the lens 34 is glass. In some embodiments, the bottom surface of the chip 38 is directly electrically connected to the package lead frame 22 via a conductive material 37, and the chip 38 is also electrically connected to the package lead frame 22 via leads 39. In some embodiments, no moisture barrier layer 24 is provided at the location where the leads 39 contact the package lead frame 22. In some embodiments, light passes through the lens 34 and illuminates the chip 38. In some embodiments, the lens 34 is attached to the inner surface of the frame structure 32. In some embodiments, a moisture barrier layer 24 is provided between the frame structure 32 and the package lead frame 22.

[0039] Figure 4 A top view of the semiconductor package structure 30 of this application is shown, wherein no moisture barrier layer 24 is provided below the chip 38, and the chip 38 is directly located on the lead frame 10.

[0040] This invention discloses a semiconductor packaging structure 30, in which a moisture barrier layer 24 is covered on a flat packaging lead frame 22. Then, the moisture barrier layer 24 is removed from the location where the lead wire 39 is to be connected and the area where the chip 38 is to be placed using exposure development, laser or sandblasting processes. Only the moisture barrier layer 24 is left to cover the junction of the lead frame 10 and the packaging compound 12. This effectively prevents water vapor from entering the cavity 36 along the delamination and forming water droplets on the surface of the lens 34, thereby affecting the light emission performance of the electronic component (VCSEL).

[0041] The moisture barrier layer 24 of this application is an elastic material, which ensures that when the sidewall of the lead frame 10 is separated from the encapsulation compound 12, the material remains continuous and crack-free to achieve a waterproof effect and improve the waterproof rating of the lead frame product.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A nail frame structure, characterized in that, include: Encapsulated lead frame; as well as A moisture barrier layer is disposed on the upper surface of the encapsulation lead frame and covers the interface between the encapsulation compound and the lead frame. The frame structure and the lens supported by the frame structure together form a cavity with the encapsulation lead frame; Below the vertical portion of the frame structure, the encapsulating compound has a top surface separate from the frame structure and a mating surface penetrating the lead frame. The moisture-blocking layer is located above the top surface and spans the bonding surface. The moisture barrier layer extends from below the vertical portion of the frame structure into the cavity and is disposed directly above each of the encapsulation compounds around the chip inside the cavity. The moisture barrier layer extends continuously on the top surface of each encapsulation compound exposed by the lead frame and is interrupted on the surface of the lead frame.

2. The nail frame structure according to claim 1, characterized in that, The encapsulated leadframe is formed by coating the leadframe with the encapsulation compound.

3. The nail frame structure according to claim 1, characterized in that, The upper surface of the encapsulated compound and the upper surface of the lead frame are coplanar.

4. The nail frame structure according to claim 1, characterized in that, The moisture barrier layer is in contact with both the encapsulation compound and the lead frame.

5. The nail frame structure according to claim 4, characterized in that, The lower surface of the moisture barrier layer is coplanar with the upper surface of the encapsulation compound and the upper surface of the lead frame.

6. The nail frame structure according to claim 1, characterized in that, The moisture barrier layer is made of adhesive or membrane material.

7. The nail frame structure according to claim 6, characterized in that, The moisture barrier layer is a liquid adhesive material, and the moisture barrier layer is formed on the encapsulation lead frame by printing.

8. The nail frame structure according to claim 7, characterized in that, The moisture barrier layer further fills the recess at the junction of the encapsulation compound and the lead frame.

9. The nail frame structure according to claim 6, characterized in that, The moisture barrier layer is a solid film material, and it is formed on the encapsulation lead frame by molding.

10. The nail frame structure according to claim 1, characterized in that, The encapsulation compound has a different coefficient of thermal expansion than the lead frame.

11. The nail frame structure according to claim 10, characterized in that, An air gap is formed between the encapsulation compound and the lead frame, and the moisture barrier layer seals the air gap.

12. A semiconductor packaging structure, characterized in that, include: Encapsulated lead frame; A moisture barrier layer is disposed on the upper surface of the encapsulation lead frame and covers the interface between the encapsulation compound and the lead frame. The frame structure and the lens supported by the frame structure, together with the packaging lead frame, form a cavity, and the chip is located in the cavity and electrically connected to the packaging lead frame; Below the vertical portion of the frame structure, the encapsulating compound has a top surface separate from the frame structure and a mating surface penetrating the lead frame. The moisture-blocking layer is located above the top surface and spans the joint surface. The moisture barrier layer extends from below the vertical portion of the frame structure into the cavity and is disposed around the chip directly above each of the encapsulation compounds. The moisture barrier layer extends continuously on the top surface of each encapsulation compound exposed by the lead frame and is interrupted on the surface of the lead frame.

13. The semiconductor packaging structure according to claim 12, characterized in that, The moisture barrier layer is not provided between the chip and the packaging lead frame.

14. The semiconductor packaging structure according to claim 13, characterized in that, The moisture barrier layer is disposed on the upper surface of the packaging lead frame surrounding the chip.

15. The semiconductor packaging structure according to claim 12, characterized in that, The lens is made of glass.

16. The semiconductor packaging structure according to claim 12, characterized in that, The chip is also electrically connected to the package lead frame via leads.

17. The semiconductor packaging structure according to claim 16, characterized in that, The moisture barrier layer is not provided at the location where the lead wire contacts the encapsulation lead frame.

18. The semiconductor packaging structure according to claim 12, characterized in that, Light passes through the lens and illuminates the chip.

19. The semiconductor packaging structure according to claim 12, characterized in that, The lens is attached to the inner surface of the frame structure.

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