Semiconductor packaging structure
By applying nickel and tin plating to the lead frame pin surfaces, the problem of plating cracking in semiconductor packaging structures at high temperatures was solved, achieving structural stability under high-temperature conditions.
Patent Information
- Application Number
- CN202520483131.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-03-19
AI Technical Summary
Existing semiconductor packaging structures are prone to delamination and cracking of the plating on the pins and/or heat sinks from the circuit board under high-temperature conditions.
A nickel plating layer and a tin plating layer are sequentially applied to the surface of the lead frame pins. The high density and high melting point of nickel prevent the formation of a copper-tin alloy layer and thus prevent cracking.
It effectively prevents the formation of a fragile copper-tin IMC layer on the pins and/or heat sinks of semiconductor devices under high-temperature conditions, avoiding delamination and cracking of the plating and circuit board.
Smart Images
Figure CN223928816U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to integrated circuit packaging field, concretely is a high temperature resistant semiconductor packaging structure. BACKGROUND
[0002] Chip packaging is a kind of technology that integrated circuit is packed with insulating plastic package material, not only plays the role of placing, fixing, sealing, protecting chip and enhancing heat conduction performance, and is also the bridge between chip internal world and external circuit.
[0003] As shown in Figure 1 And Figure 2 In prior art semiconductor packaging structure, the pin and / or the surface of the heat sink exposed to the outside of the plastic package body are usually tinned. However, when the packaged semiconductor device is welded on a single board for field use, the tinning layer of the pin and / or the heat sink of the device is prone to delamination and cracking from the single board after a period of time. The reason is that the tinning layer of the existing product rapidly generates copper-tin alloy under high temperature conditions (natural high temperature generated during work or high temperature environment when replacing other unit parts at 400 DEG C), forming a brittle copper-tin IMC layer, which cracks under temperature change and mechanical stress. SUMMARY
[0004] The utility model discloses a kind of high temperature resistant power semiconductor packaging structures.
[0005] In the embodiment of the utility model, a semiconductor packaging structure is provided, which includes a lead frame base island, a lead frame pin, a chip disposed on the lead frame base island, and a plastic package body encapsulating the chip, the lead frame base island and the lead frame pin into one. At least one surface of the lead frame pin is exposed outside the plastic package body, and a nickel plating layer and a tin plating layer are sequentially disposed on the exposed surface of the lead frame pin.
[0006] In the embodiment of the utility model, the plastic package body wraps the chip, the lead frame base island and the lead frame pin. The lead frame pin extends from the plastic package body. Nickel plating layers and tin plating layers are sequentially disposed on the upper and lower surfaces of the lead frame pin.
[0007] In the embodiment of the utility model, the lead frame base island and the lead frame pin are located in the same plane. The plastic package body wraps the chip, the lead frame base island and the lead frame pin. The lead frame pin extends from the plastic package body.
[0008] In the embodiment of the utility model, DAF glue or mounting glue is disposed between the chip and the lead frame pin.
[0009] The lead frame pin and the chip are kept electrically connected through a lead.
[0010] Compared with the prior art, the semiconductor packaging structure of the utility model is provided with nickel plating layer and tin plating layer on the surface of the pin and / or the radiating fin in sequence, since the density of nickel is extremely high, copper molecules and tin molecules cannot effectively pass through the nickel layer, and the melting point of nickel is 1453 DEG C, and the blocking effect can be stably exerted under the condition of 400 DEG C, the phenomenon of delamination and cracking of the plating layer and the circuit board of the pin and / or the radiating fin of the peninsula body device can be prevented. BRIEF DESCRIPTION OF DRAWINGS
[0011] Figure 1 It is a sectional structure schematic view of a prior art semiconductor packaging structure.
[0012] Figure 2 It is a sectional structure schematic view of another prior art semiconductor packaging structure.
[0013] Figure 3 It is a sectional structure schematic view of a semiconductor packaging structure of an embodiment of the utility model.
[0014] Figure 4 It is a sectional structure schematic view of a semiconductor packaging structure of another embodiment of the utility model. DETAILED DESCRIPTION
[0015] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the utility model is further described in detail below by combining with the drawings and embodiments.
[0016] The implementation of the utility model is described in detail below by combining with specific embodiments.
[0017] As shown in the drawings, Figure 3 An embodiment of the utility model provides a semiconductor packaging structure, which comprises a lead frame base island 30, a lead frame pin 31, a chip 32 arranged on the lead frame base island 30 and a plastic package 33 for packaging the chip 32, the lead frame base island 30 and the lead frame pin 31 into one body. The chip 32 and the lead frame pin 31 are connected and fixed through adhesive 34. The adhesive 34 can be DAF glue or chip mounting glue. The lead frame pin 31 and the chip 32 are kept electrically connected through a lead 35.
[0018] Furthermore, both the leadframe base island 30 and the leadframe pins 31 are sheet-like structures located on the same plane and each has upper and lower surfaces. The molding compound 33 covers the chip 32, the leadframe base island 30, and the leadframe pins 31, exposing the back surfaces of the leadframe base island 30 and the leadframe pins 31 outside the molding compound 33. A nickel plating layer 36 and a tin plating layer 37 are sequentially disposed on the exposed surfaces of the leadframe base island 30 and the leadframe pins 31. This configuration allows the exposed portion of the leadframe base island 30 to form a heat sink for the semiconductor package structure. The leadframe base island 30 and the leadframe pins 31 can be surface-mounted onto a circuit board.
[0019] Using the above-mentioned semiconductor packaging structure, a nickel plating layer and a tin plating layer are sequentially formed on the surface of the pins and / or heat sink. Due to the extremely high density of nickel, copper and tin molecules cannot effectively pass through the nickel layer. Furthermore, nickel has a melting point of 1453°C and can stably play a blocking role even at 400°C. This can prevent the formation of a brittle copper-tin IMC layer on the surface of the pins and / or heat sink of the penetrating device at high temperatures, thereby preventing the plating of the pins and / or heat sink of the penetrating device and the circuit board from delamination and cracking.
[0020] like Figure 3 As shown, unlike the above embodiments, in another embodiment of this utility model, the molding compound 33 encapsulates the chip 32, the lead frame base island 30, and the lead frame pins 31, with the lead frame pins 31 extending from the molding compound 33. The upper and lower surfaces of the lead frame pins 31 are sequentially provided with a nickel plating layer 36 and a tin plating layer 37. In this embodiment, the back side of the lead frame base island 30 is completely encapsulated by the molding compound 33, and no heat sink is formed.
[0021] Of course, this utility model is not limited to the above embodiments. As long as at least one surface of the lead frame pin 31 is exposed outside the encapsulation body 33, and a nickel plating layer 36 and a tin plating layer 37 are sequentially provided on the exposed surface of the lead frame pin 31, it is acceptable.
[0022] In summary, the semiconductor packaging structure of this invention, with nickel plating and tin plating sequentially deposited on the surface of the pins and / or heat sink, utilizes the high density of nickel to prevent copper and tin molecules from effectively penetrating the nickel layer. Furthermore, nickel's melting point of 1453℃ ensures stable blocking even at 400℃. This prevents the formation of a brittle copper-tin IMC layer on the surface of the pins and / or heat sink of the semiconductor device at high temperatures, thereby preventing delamination and cracking of the plating on the pins and / or heat sink and the circuit board.
[0023] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A semiconductor package structure, comprising: The lead frame base island, the lead frame pin, the chip arranged on the lead frame base island, and the plastic package body encapsulating the chip, the lead frame base island and the lead frame pin into one body, at least one surface of the lead frame pin is exposed outside the plastic package body, and a nickel plating layer and a tin plating layer are sequentially arranged on the exposed surface of the lead frame pin.
2. The semiconductor package structure of claim 1, wherein, The lead frame base island and the lead frame pin are located in the same plane, the plastic package body covers the chip, the lead frame base island and the lead frame pin, and the back surfaces of the lead frame base island and the lead frame pin are exposed outside the plastic package body, and a nickel plating layer and a tin plating layer are sequentially arranged on the exposed surfaces of the lead frame base island and the lead frame pin.
3. The semiconductor package structure of claim 1, wherein, The plastic package body encapsulates the chip, the lead frame base island and the lead frame pin, the lead frame pin extends out of the plastic package body, and a nickel plating layer and a tin plating layer are sequentially arranged on the upper and lower surfaces of the lead frame pin.
4. The semiconductor package structure of claim 1, wherein, DAF glue or a chip mounting glue is arranged between the chip and the lead frame pin.
5. The semiconductor package structure of claim 1, wherein, The lead frame pin and the chip are electrically connected through a lead.