CN108109972B - Semiconductor packaging structure with pin side wall tin climbing function and manufacturing process thereof - Google Patents

Abstract

The present invention relates to a semiconductor packaging structure with the function of tin climbing on the sidewall of a lead and a manufacturing process thereof. The structure includes a base island and a lead, the lead includes a plane part and a sidewall part, and the sidewall part is located in On the outside of the plane part, the plane part and the side wall part are connected by a smooth transition through an arc-shaped part, the convex surface of the arc-shaped part faces the outer lower side, the front side of the base island is provided with a chip, and the chip is connected by a metal bonding wire The base island, the pin and the peripheral area of the chip are encapsulated with plastic encapsulation compound, and the outer surfaces of the flat portion, the arc portion and the side wall portion are exposed to the outside of the encapsulated compound. When soldering the PCB, the solder can climb to a higher height along the vertical sidewall, thereby increasing the bonding area between the solder and the pin, and at the same time, the air at the pin can be discharged along the convex arc, thereby improving the product quality. Welding performance, welding reliability and visual inspection of welding status.

Description

Semiconductor package structure with pin sidewall creeping tin function and its manufacturing process

technical field

The invention relates to a semiconductor packaging structure with the function of tin climbing on the sidewall of a pin and a manufacturing process thereof, belonging to the technical field of semiconductor packaging.

Background technique

With the development of modern technology, semiconductor packaging has been widely used. It is widely used in radar, remote control telemetry, aerospace, etc., which puts forward higher and higher requirements for its reliability. And the failure caused by poor semiconductor welding has attracted more and more attention, because this kind of failure is often fatal and irreversible. Therefore, it is very important to obtain a good soldering reliability in the semiconductor industry. The tin layer of the semiconductor soldering surface can make the soldering more solid, especially for automotive electronics.

As we all know, QFN (Quad Flat No-lead Package) and DFN (Duad Flat No-lead Package) are leadless packages with a large exposed area in the center. The pads have thermal conductivity, and there are conductive pads for electrical connection on the periphery of the package of the large pads. Usually, the thermally conductive pads and the conductive pads are mounted on the circuit board together, but in the prior art, the side of the metal pins after the plastic package is cut has no tin layer interface, so that the solder paste on the PCB board cannot climb the plastic package. Metal areas on the sides. However, the problem of virtual welding or cold welding on the side of the metal pins cannot be clearly inspected in appearance, especially in the first-level and second-level safety applications in automotive electronics, so the side metal pins of the plastic body The climbing tin is particularly important.

In order to solve this problem, it is a common practice in the industry to cut the outer end of the back of the lead frame lead (see Figure 1A) to form a stepped step, and then perform the subsequent cutting operation (see Figure 1B), so that the side of the lead can be obtained. Stepped package structure (see Figure 1C), thereby improving its reliability when soldering to the PCB.

However, when the exposed pads and conductive pads at the bottom of the package structure with stepped pins are welded to the thermal pads on the PCB, as shown at A in Figure 1D, air is likely to remain at the pin steps and cannot be discharged. Causes poor solder bonding. Especially when the product is working, the air remaining in the step will expand due to the heating of the product, which will cause the cracking of the tin layer between the PCB pad and the pins of the plastic package, resulting in poor electrical function of the integrated circuit. It will also directly cause the electrical function to stop working.

In addition, in the manufacturing process of the package structure with stepped pins, it is necessary to cut the outer ends of the backside of the lead frame pins first, and then to cut the front side of the packaged lead frame, which requires two cutting operations. It will reduce the cutting efficiency, and also easily accelerate the wear and tear of the cutting tool, which increases the manufacturing cost.

Another practice in the industry is to half-etch the outer ends of the backside of the lead frame pins to form drop-shaped grooves (see Figure 1E). Due to the etching characteristics, the grooves formed by this method will be concave arcs. The pin groove of this structure is also prone to residual air that cannot be discharged (see Figure 1F), resulting in poor solder bonding.

In addition, there is a package structure with an L-shaped outer lead (see Figure 1G) or a J-shaped outer lead (see Figure 1H) in the industry, which uses the lead frame of the traditional outer lead package for chip mounting, wire bonding, and encapsulation. Before the punching process, it has a certain length of outer pins (see Figure 1I). During the punching process, the molding die needs to be inserted between the outer pins and the plastic body, and the outer pins should face the side of the plastic body. Bending to make L-shaped outer pins or C-shaped outer pins, this kind of L-shaped outer pins or C-shaped outer pins package, because the outer pins have a considerable height, so in the package structure When mounted on the PCB board, the solder will climb to a certain height along the outer pins due to capillary phenomenon, so that it has a higher welding strength when welding the PCB.

However, this kind of package structure that forms L-shaped outer pins or C-shaped outer pins by cutting ribs also has the following defects when forming L-shaped outer pins or C-shaped outer pins. When the lead is formed, the outer lead is bent towards the side of the plastic body. The inner lead at A in Figure 1G and Figure 1H will be affected by the rebound force of the metal, causing the metal lead to move downward and outward from the plastic body. When the force is downward, it is easy to cause delamination between the upper surface of the inner pin at A and the lower surface of the plastic compound. In severe cases, it will even lead to an open circuit between the bonding wire at A and the inner pin, resulting in product failure. , Bending the outer pin towards the side of the plastic package is to extend the molding die between the outer pin and the plastic package and then bend it. Because the metal pin has a certain elastic coefficient, the outer pin will be stressed and will return. The relationship between the spring and the spring makes the outer pin form a larger trumpet-shaped opening as shown at B in Figure 1J, and it is difficult to form a shape that is vertically close to the side of the plastic body as shown in Figure 1G; finally, the L-shaped external lead The lead or C-shaped outer lead package structure has a larger volume, because the outer leads are bent to form an L-shaped outer lead or C-shaped outer lead package structure, which is compared with the traditional inner lead package. , has a wider package width, which is not conducive to the development trend of miniaturized packages.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a semiconductor package structure with the function of tin-climbing on the sidewall of the pins in view of the above-mentioned prior art. For the side wall part, when soldering the PCB, the solder can climb to a higher height along the vertical side wall part, thereby increasing the bonding area of the solder and the pins, and the soldering state can be clearly distinguished from the appearance of the solder climbing state. In addition, the convex arc structure of the pin can make the air at the pin discharge along the convex arc while climbing the tin, which can avoid the bubbles remaining in the solder, which will affect the combination of the pin and the PCB, thereby improving the welding of the product. performance, reliability of welding, and visual inspection of the welding state; finally, the present invention provides a thickened copper sheet on the back of the base island, which further satisfies the requirement of high heat dissipation of power semiconductors.

The present invention is a manufacturing process of a semiconductor package structure with the function of tin climbing on the sidewall of the pin, which utilizes an etching process to form a groove with a certain depth on a carrier plate, and then electroplating a metal layer in the groove to form a vertical groove. For the pins with straight side walls, since the vertical side walls of the pins are formed by electroplating, rather than cutting and forming the outer pins of the traditional frame, the formation process of the side walls will not be affected by the metal of the metal pins. Rebound stress causes delamination between the lead and the molding compound, which affects product reliability. In addition, the present invention does not need to perform cutting, so the original array-type plastic package can be singulated only by removing the carrier plate, which fully saves more equipment costs, production costs, material costs, labor costs and quality costs in the cutting process; The present invention forms the thickened base island by two electroplating, and further satisfies the requirement of high heat dissipation of the power semiconductor.

The present invention is a manufacturing process of a semiconductor package structure with the function of climbing tin on the sidewalls of pins. It uses an etching process to form a groove with a certain depth on a carrier board, and firstly installs a thickened copper plate at the position of the base island in the groove. Then, by electroplating the metal layer in the groove, the pins with vertical sidewalls can be formed. Because the vertical sidewalls of the pins are formed by electroplating, instead of cutting ribs and forming the outer pins of the traditional frame. Therefore, the formation process of the sidewall will not affect the reliability of the product due to the metal springback stress of the metal lead causing the delamination between the lead and the plastic package. In addition, the present invention does not require cutting, so the original array-type plastic package can be singulated only by removing the carrier plate, which fully saves more equipment costs, production costs, material costs, labor costs and quality costs in the cutting process.

The technical solution adopted by the present invention to solve the above problems is: a semiconductor package structure with the function of climbing tin on the sidewalls of pins, which includes a base island and pins, the pins are arranged around the base island, and the front side of the base island is A thickened layer is provided, the base island and the thickened layer form a thickened base island, the height of the thickened base island is higher than the height of the lead, the lead includes a plane part and a side wall part, the side The wall part is located outside the plane part, the plane part and the side wall part are connected by a smooth transition through an arc part, the convex surface of the arc part faces the outer lower side, the front side of the thickened base island is provided with a chip, the The chip is electrically connected to the pins through metal bonding wires, the pins, the base island and the peripheral area of the chip are encapsulated with a plastic sealing compound, the height of the side wall portion is flush with the plastic sealing compound, the flat portion, the arc-shaped The inner surfaces of the portion and the sidewall portion are encapsulated within the molding compound, and the outer surfaces of the flat portion, the arcuate portion and the sidewall portion are all exposed to the molding compound.

A semiconductor package structure with a pin sidewall tin-climbing function, which includes a copper sheet, a pin and a base island, the surface of the copper sheet is provided with a base island, the pins are arranged around the copper sheet, and the pins It includes a plane portion and a sidewall portion, the sidewall portion is located outside the plane portion, the plane portion and the sidewall portion are connected by a smooth transition through an arc-shaped portion, the convex surface of the arc-shaped portion faces the outer lower side, and the The front side of the base island is provided with a chip, and the chip is electrically connected to the pins through metal bonding wires. The pins, the base island and the peripheral area of the chip are encapsulated with a plastic sealing compound, and the height of the side wall portion is the same as that of the plastic sealing compound. flat, the inner surfaces of the flat portion, the arc portion and the side wall portion are covered in the molding compound, and the outer surfaces of the flat portion, the arc portion and the side wall portion are all exposed outside the molding compound.

The pins and base islands are metal circuit layers formed by electroplating.

A manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function, the process comprises the following steps:

Step 1. Take a piece of metal carrier plate;

Step 2: Paste or print a photoresist material that can be exposed and developed on the front and back of the metal carrier, and use exposure and developing equipment to expose, develop and remove part of the photoresist material on the surface of the metal carrier to expose the metal The surface of the carrier board needs to be etched pattern area;

Step 3: Chemical etching is performed on the area where the exposure and development are completed on the front of the metal carrier, and the groove is formed by etching. photoresist film;

Step 4: Electroplating a metal circuit layer in the front groove of the metal carrier to form a base island and a pin, the pin includes a flat part and a side wall part, the side wall part is located outside the flat part, and between the flat part and the side wall part Smooth transition connection through the arc-shaped part, the convex surface of the arc-shaped part faces the outer lower side, and the height of the side wall part is flush with the top surface of the groove;

Step 5, electroplating the metal circuit layer on the base island in the front groove of the metal carrier plate again to form a thickened base island;

Step 6: Coating bonding material or solder on the surface of the thickened base island, then implanting a chip on the bonding material or solder, and bonding metal wires between the front side of the chip and the front side of the pins;

Step 7. Use plastic sealing compound to seal the metal carrier plate that has completed the chip loading and wire bonding operations in Step 6;

Step 8: Remove the metal carrier plate to expose the outer surface of the pin and the thickened base island, and separate the original array-type plastic package to obtain a semiconductor package structure with the function of tin climbing on the side of the pin.

A manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function, the process comprises the following steps:

Step 1. Take a piece of metal carrier plate;

Step 2: Paste or print a photoresist material that can be exposed and developed on the front and back of the metal carrier, and use exposure and developing equipment to expose, develop and remove part of the photoresist material on the surface of the metal carrier to expose the metal The surface of the carrier board needs to be etched pattern area;

Step 3: Chemical etching is performed on the area where the exposure and development are completed on the front of the metal carrier, and the groove is formed by etching. photoresist film;

Step 4, setting a copper sheet at the position of the subsequent electroplating base island in the front groove of the metal carrier;

Step 5: A metal circuit layer is electroplated on the copper sheet in the front groove of the metal carrier to form a base island, and a metal circuit layer is plated on the surrounding part of the copper sheet in the front groove of the metal carrier to form a pin, and the pin includes: The plane part and the side wall part, the side wall part is located outside the plane part, the plane part and the side wall part are connected by a smooth transition through the arc part, the convex surface of the arc part faces the outer lower side, the height of the side wall part is the same as the concave part. The top surface of the groove is flush;

Step 6: Coating bonding material or solder on the surface of the base island, then implanting the chip on the bonding material or solder, and bonding metal wire between the front side of the chip and the front side of the pin;

Step 7. Use plastic sealing compound to seal the metal carrier plate that has completed the chip loading and wire bonding operations in Step 6;

Step 8: Remove the metal carrier plate to expose the outer surfaces of the pins and the copper sheet, and separate the original array-type plastic package to obtain a semiconductor package structure with a tin-climbing function on the side of the pins.

The etching potion uses copper chloride or ferric chloride.

The photoresist film is removed by softening with chemical solution and rinsing with high pressure water.

The metal circuit layer material is copper, aluminum or nickel.

The material of the metal bonding wire is gold, silver, copper or aluminum; the shape of the metal bonding wire is wire or ribbon.

The encapsulation method of the plastic encapsulation material adopts the mold filling method, the spraying method of spraying equipment, or the gluing method, and the plastic encapsulating material adopts epoxy resin with filler substance or without filler substance.

Compared with the prior art, the advantages of the present invention are:

1. A semiconductor package structure with a pin sidewall tin-climbing function of the present invention and a manufacturing process thereof, which are electroplated in the groove formed by the etching of the carrier plate to directly form an arc-shaped portion with an external convexity, and are connected with it and plastic-sealed. When soldering the PCB, the solder can climb to a higher height along the vertical sidewall, thereby increasing the bonding area between the solder and the pin, and its climbing state can be clearly seen from the appearance. It can be seen from the ground that in addition, the convex arc structure of the pin can make the air at the pin discharge along the convex arc while climbing the tin, so as to avoid residual air bubbles in the solder, which will affect the combination of the pin and the PCB. It can improve the welding performance and reliability of the product;

2. In the present invention, a semiconductor package structure with a tin-climbing function on the sidewalls of the pins and its manufacturing process, the vertical sidewalls of the pins are formed by electroplating, instead of the outer pins of the traditional frame being cut and formed. The formation process of its sidewalls will not cause delamination between the lead and the plastic package, thus affecting the reliability of the product;

3. A semiconductor package structure with a pin sidewall tin-climbing function of the present invention and a manufacturing process thereof, which form a thickened base island through two electroplatings or set a thickened copper sheet under the base island, further satisfying the meet the high heat dissipation requirements of power semiconductors;

4. A semiconductor package structure with a pin sidewall tin-climbing function of the present invention and its manufacturing process do not need to be cut, so the original array-type plastic package can be singulated only by removing the carrier, so it can be Save cutting costs.

Description of drawings

1A-1B are schematic diagrams of two cutting operations for manufacturing a package structure with stepped pins in the prior art.

FIG. 1C is a schematic diagram of a conventional package structure with stepped pins.

FIG. 1D is a schematic diagram of a conventional package structure with stepped pins combined with a PCB board.

FIG. 1E is a schematic diagram of a conventional package structure in which a lead has a drop-shaped groove.

FIG. 1F is a schematic diagram of a conventional package structure with water drop-shaped grooves combined with a PCB board.

FIG. 1G is a schematic diagram of a conventional package structure with L-shaped outer leads.

FIG. 1H is a schematic diagram of a conventional package structure with C-shaped outer leads.

FIG. 1I is a schematic structural diagram of an existing package structure with L-shaped outer leads or C-shaped outer leads before rib-cutting molding.

FIG. 1J is a schematic structural diagram of a conventional package structure with L-shaped outer leads after rib-cutting is formed.

FIG. 2 is a schematic diagram of Embodiment 1 of a semiconductor package structure with a pin sidewall creeping function of the present invention.

FIG. 3 is a schematic perspective view of Embodiment 1 of a semiconductor package structure with a lead sidewall creeping function of the present invention.

FIG. 4 is a schematic diagram of the combination of Embodiment 1 of a semiconductor package structure with a pin sidewall tin-climbing function of the present invention and a PCB board.

5 to 15 are schematic flowcharts of a manufacturing process of a semiconductor package structure with lead sidewall creeping function of the present invention.

FIG. 16 is a schematic diagram of Embodiment 2 of a semiconductor package structure with a lead sidewall creeping function of the present invention.

FIG. 17 is a schematic perspective view of Embodiment 2 of a semiconductor package structure with a lead sidewall creeping function of the present invention.

FIG. 18 is a schematic diagram of the combination of Embodiment 2 of a semiconductor package structure with a pin sidewall tin-climbing function of the present invention and a PCB board.

19 to 29 are schematic flowcharts of a manufacturing process of a semiconductor package structure with lead sidewall creeping function of the present invention.

in:

Key Island 1

pin 2

Flat part 2.1

Arc section 2.2

Side wall section 2.3

Thickening layer 3

Bonding Substance or Solder 4

chip 5

Metal Bonding Wire 6

Molding compound 7

Copper sheet 8.

Detailed ways

The present invention will be further described in detail below with reference to the embodiments of the accompanying drawings.

Example 1: Two times of electroplating to form thickened base islands

As shown in FIG. 2 and FIG. 3 , a semiconductor package structure with a pin sidewall tin-climbing function in this embodiment includes a base island 1 and a pin 2, and the pins 2 and the base island 3 are electroplated The formed metal circuit layer, the pins 2 are arranged around the base island 3, the front side of the base island 1 is provided with a thickened layer 3, the base island 1 and the thickened layer 3 form a thickened base island, and the thickened layer 3 is formed. The height of the thick base island is higher than the height of the lead 2, the lead 2 includes a flat part 2.1 and a side wall part 2.3, the side wall part 2.3 is located outside the flat part 2.1, the flat part 2.1 and the side wall part 2.3 The arc-shaped part 2.2 is used for smooth transition connection, the convex surface of the arc-shaped part 2.2 faces the outer and lower side, and the front side of the thickened base island is provided with a chip 5 through a bonding substance or solder 4, and the chip 5 is welded by metal. The wire 6 is electrically connected to the pin 2. The pin 2, the base island 3 and the peripheral area of the chip 5 are encapsulated with a plastic compound 7. The height of the side wall portion 2.3 is flush with the plastic compound 7, and the plane The inner surfaces of the portion 2.1, the arcuate portion 2.2 and the sidewall portion 2.3 are encapsulated within the molding compound 7, and the outer surfaces of the flat portion 2.1, the arcuate portion 2.2 and the sidewall portion 2.3 are all exposed to the molding compound 7 ;

4 is a schematic diagram of the combination of a semiconductor package structure with a pin sidewall tin-climbing function and a PCB board according to the present invention. In the present invention, a convex arc is directly formed in the groove formed by the etching of the carrier board and is connected to it. For pins with the same height as the plastic compound, the solder can climb to a higher height along the vertical sidewalls when soldering the PCB, thereby increasing the bonding area between the solder and the pins, and its climbing state can be clearly seen from the appearance. It can be seen from the ground that in addition, the convex arc structure of the pin can make the air at the pin discharge along the convex arc while climbing the tin, so as to avoid residual air bubbles in the solder, which will affect the combination of the pin and the PCB. It can improve the welding performance and reliability of the product.

A manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function, the process comprises the following steps:

Step 1. Referring to Figure 5, take a metal carrier plate with a suitable thickness. The purpose of this plate is to provide support for circuit production and circuit layer structure. The material of this plate is mainly metal materials, and the material of metal materials can be Copper, iron, stainless steel or other metal substances with conductive function;

Step 2: Referring to FIG. 6, a photoresist material that can be exposed and developed is pasted or printed on the front and back of the metal carrier to protect the subsequent metal layer etching process. The photoresist material can be a photoresist film or a photoresist. Referring to FIG. 7, the photoresist material on the surface of the metal carrier is exposed, developed and removed by using an exposure and developing device, so as to expose the area of the metal carrier surface that needs to be etched;

Step 3. Referring to Figure 8, chemical etching is performed on the area where the exposure and development are completed on the front side of the metal carrier, and the etching forms grooves. The bottom and sidewalls of the grooves are flat. Due to the etching characteristics, the connection between the bottom and the sidewalls will be etched into an arc shape. . The etching potion can be copper chloride or ferric chloride or other potions that can be chemically etched. Referring to FIG. 9, after the etching is completed, the photoresist film on the surface of the metal carrier is removed, and the method for removing the photoresist film can be softened by chemical solution and removed by high-pressure water rinsing;

Step 4, referring to Figure 10, electroplating a metal circuit layer in the groove on the front side of the metal carrier to form a base island and a pin, the pin includes a flat part and a side wall part, the side wall part is located outside the flat part, the flat part and the side The wall parts are connected by a smooth transition through an arc-shaped part, the convex surface of the arc-shaped part faces the outer lower side, the height of the side wall part is flush with the top surface of the groove, and the material of the metal circuit layer is usually copper, aluminum, nickel, etc., It can also be other conductive metal substances;

Step 5, referring to Figure 11, the metal circuit layer is electroplated on the base island in the groove on the front side of the metal carrier plate again to form a thickened base island. The material of the metal circuit layer is usually copper, aluminum, nickel, etc., or other conductive materials. metal substance;

Step 6. Referring to Fig. 12, the surface of the thickened base island is coated with a bonding substance or solder, and then a chip is implanted on the bonding substance or solder. The metal bonding wire is bonded between the front side of the chip and the front side of the pin. The material of the metal bonding wire is gold, silver, copper, aluminum or alloy material, and the shape of the metal bonding wire can be filament or ribbon;

Step 7. Referring to Figure 13, the metal carrier plate that has been loaded and wired in Step 6 is plastic-sealed with plastic sealing compound. The packaging method of the plastic sealing compound can be the mold filling method, the spraying equipment spraying method or the glue brushing method. The molding compound can be epoxy resin with filler material or without filler material;

Step 8. Referring to Figure 14 and Figure 15, remove the metal carrier plate to expose the outer surface of the pins and the thickened base island, and separate the original array-type plastic package to obtain a tin-climbing tin on the side of the pins. Functional semiconductor package structure.

The invention provides a manufacturing process of a semiconductor package structure with a function of tin climbing on the sidewalls of pins. An etching process is used to form a groove with a certain depth on a carrier board, and then a metal layer is electroplated in the groove to form a vertical groove. For the pins with straight sidewalls, since the vertical sidewalls of the pins are formed by electroplating, rather than the outer pins of the traditional frame being formed by cutting ribs, the formation process of the sidewalls will not cause the pins and the molding compound to be formed. stratification between, thereby affecting the reliability of the product. In addition, the present invention does not require cutting, so the original array-type plastic package can be singulated only by removing the carrier plate, so the cutting cost can be saved.

Example 2: Setting copper sheets under the chip

As shown in FIG. 16 and FIG. 17 , in this embodiment, a semiconductor package structure with the function of tin climbing on the sidewalls of the pins includes copper sheets 8 , pins 2 , and a base island 1 . The surface of the copper sheets 8 is provided with There is a base island 1, the pin 2 and the base island 1 are metal circuit layers formed by electroplating, the pin 2 is arranged around the copper sheet 8, and the pin 2 includes a plane portion 2.1 and a side wall portion 2.3, so The side wall portion 2.3 is located outside the plane portion 2.1, the plane portion 2.1 and the side wall portion 2.3 are connected by a smooth transition through an arc-shaped portion 2.2, the convex surface of the arc-shaped portion 2.2 faces the outer lower side, and the base island 1 The front side is provided with a chip 5 through a bonding substance or solder 4, the chip 5 is electrically connected to the pin 2 through a metal wire 6, and the pin 2, the base island 1 and the peripheral area of the chip 5 are encapsulated with a plastic sealing compound 7. The height of the side wall portion 2.3 is flush with the molding compound 7, the inner surfaces of the flat portion 2.1, the arc portion 2.2 and the side wall portion 2.3 are wrapped in the molding compound 7, and the flat portion 2.1, The outer surfaces of the arc portion 2.2 and the side wall portion 2.3 are both exposed to the outside of the molding compound 7;

18 is a schematic diagram of the combination of a semiconductor package structure with a pin sidewall tin-climbing function of the present invention and a PCB board. In the present invention, an arc with a convex shape is directly formed by electroplating in the groove formed by the etching of the carrier board and is connected to it. For pins with the same height as the plastic compound, the solder can climb to a higher height along the vertical sidewalls when soldering the PCB, thereby increasing the bonding area between the solder and the pins, and its climbing state can be clearly seen from the appearance. It can be seen from the ground that in addition, the convex arc structure of the pin can make the air at the pin discharge along the convex arc while climbing the tin, so as to avoid residual air bubbles in the solder, which will affect the combination of the pin and the PCB. It can improve the welding performance and reliability of the product.

A manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function, the process comprises the following steps:

Step 1. Referring to Figure 19, take a metal carrier plate of suitable thickness. The purpose of this plate is to provide support for circuit production and circuit layer structure. The material of this plate is mainly metal materials, and the material of metal materials can be Copper, iron, stainless steel or other metal substances with conductive function;

Step 2: Referring to FIG. 20 , paste or print a photoresist material that can be exposed and developed on the front and back of the metal carrier to protect the subsequent metal layer etching process. The photoresist material can be a photoresist film or a photoresist. Referring to FIG. 21 , the photoresist material on the surface of the metal carrier is exposed, developed and removed by using an exposure and developing device, so as to expose the pattern area on the surface of the metal carrier that needs to be etched;

Step 3. Referring to Figure 22, chemical etching is performed in the area where the exposure and development are completed on the front of the metal carrier, and the etching forms grooves. The bottom and sidewalls of the grooves are flat. Due to the etching characteristics, the connection between the bottom and the sidewalls will be etched into an arc shape. . The etching potion can be copper chloride or ferric chloride or other potions that can be chemically etched. Referring to Figure 23, after the etching is completed, the photoresist film on the surface of the metal carrier is removed, and the method of removing the photoresist film can be softened by chemical solution and rinsed with high pressure water to remove the photoresist film;

Step 4, referring to FIG. 24, set a copper sheet at the position of the subsequent electroplating base island in the groove on the front side of the metal carrier;

Step 5: Referring to Figure 25, a metal circuit layer is plated on the copper sheet in the front groove of the metal carrier to form a base island, and a metal circuit layer is plated on the surrounding part of the copper sheet in the front groove of the metal carrier to form a pin , the pin includes a plane part and a side wall part, the side wall part is located outside the plane part, the plane part and the side wall part are connected by a smooth transition through an arc part, the convex surface of the arc part faces the outer lower side, and the side wall part The height of the groove is flush with the top surface of the groove, and the material of the metal circuit layer is usually copper, aluminum, nickel, etc., or other conductive metal substances;

Step 6. Referring to Fig. 26, the surface of the base island is coated with a bonding substance or solder, and then a chip is implanted on the bonding substance or solder. The metal bonding wire is bonded between the front side of the chip and the front side of the pin. The material of the metal bonding wire is gold, silver, copper, aluminum or alloy material, and the shape of the metal bonding wire can be filament or ribbon;

Step 7. Referring to Figure 27, the metal carrier plate that has been loaded and wired in Step 6 is plastic-sealed with plastic sealing material. The packaging method of the plastic sealing material can be the mold filling method, the spraying equipment spraying method or the glue brushing method. The molding compound can be epoxy resin with filler material or without filler material;

Step 8. Referring to Figure 28 and Figure 29, remove the metal carrier plate to expose the outer surfaces of the pins and copper sheets, and separate the original array-type plastic package to obtain a tin-climbing function on the side of the pins. Semiconductor packaging structure.

The invention provides a manufacturing process of a semiconductor package structure with the function of climbing tin on the sidewalls of pins. An etching process is used to form a groove with a certain depth on a carrier board, and a thickened copper plate is first arranged at the position of the base island in the groove. Then, by electroplating the metal layer in the groove, the pins with vertical sidewalls can be formed. Because the vertical sidewalls of the pins are formed by electroplating, instead of cutting ribs and forming the outer pins of the traditional frame. The formation process of its sidewalls will not cause delamination between the lead and the molding compound, thereby affecting the reliability of the product. In addition, the present invention does not require cutting, so the original array-type plastic package can be singulated only by removing the carrier plate, so the cutting cost can be saved.

In addition to the above-mentioned embodiments, the present invention also includes other embodiments, and all technical solutions formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (10)

1. A semiconductor package structure with a pin sidewall climbing tin function, characterized in that it comprises a base island (1) and a pin (2), and the base island (1) and the pin (2) are electroplated The formed metal circuit layer, the pins (2) are arranged around the base island (1), the front side of the base island (1) is provided with a thickened layer (3), the base island (1) and the thickened layer (3) forming a thickened base island, the height of the thickened base island is higher than the height of the lead (2), the lead (2) includes a plane part (2.1) and a side wall part (2.3), the said The side wall part (2.3) is located outside the plane part (2.1), and the plane part (2.1) and the side wall part (2.3) are connected by a smooth transition through the arc part (2.2), the arc part (2.2) The convex surface faces the outer and lower side, the front side of the thickened base island is provided with a chip (5), the chip (5) is electrically connected to the pin (2) through a metal bonding wire (6), and the pin (2) ), the base island (1) and the peripheral area of the chip (5) are encapsulated with a plastic compound (7), the height of the side wall portion (2.3) is flush with the plastic compound (7), the plane portion (2.1), The inner surfaces of the arc portion (2.2) and the side wall portion (2.3) are encapsulated within the plastic compound (7), and the outer surfaces of the flat portion (2.1), the arc portion (2.2) and the side wall portion (2.3) The surfaces are exposed to the outside of the molding compound (7). 2. A semiconductor package structure with a pin sidewall climbing tin function, characterized in that it comprises a copper sheet (8), a pin (2) and a base island (1), the base island (1) and the lead The foot (2) is a metal circuit layer formed by electroplating, the surface of the copper sheet (8) is provided with a base island (1), the pin (2) is arranged around the copper sheet (8), and the pin (2) ) comprises a plane part (2.1) and a side wall part (2.3), the side wall part (2.3) is located outside the plane part (2.1), and an arc is formed between the plane part (2.1) and the side wall part (2.3) The part (2.2) is connected by a smooth transition, the convex surface of the arc-shaped part (2.2) faces the outer lower side, the front surface of the base island (1) is provided with a chip (5), and the chip (5) passes through the metal bonding wire (6) ) is electrically connected to the pin (2), the pin (2), the base island (3) and the peripheral area of the chip (5) are encapsulated with a plastic compound (7). The height is flush with the molding compound (7), the inner surfaces of the flat portion (2.1), the arc portion (2.2) and the side wall portion (2.3) are wrapped in the molding compound (7), and the flat portion ( 2.1), the outer surfaces of the arcuate portion (2.2) and the side wall portion (2.3) are all exposed to the molding compound (7). 3. A semiconductor package structure with a pin sidewall creeping tin function according to claim 1 or 2, wherein the pin (2) and the base island (1) are metal circuit layers formed by electroplating . 4. A manufacturing process of a semiconductor package structure with pin sidewall creeping tin function, characterized in that the process comprises the following steps: Step 1. Take a piece of metal carrier plate; Step 2: Paste or print a photoresist material that can be exposed and developed on the front and back of the metal carrier, and use exposure and developing equipment to expose, develop and remove part of the photoresist material on the surface of the metal carrier to expose the metal The surface of the carrier board needs to be etched pattern area; Step 3: Chemical etching is performed on the area where the exposure and development are completed on the front of the metal carrier, and the groove is formed by etching. photoresist film; Step 4: Electroplating a metal circuit layer in the front groove of the metal carrier to form a base island and a pin, the pin includes a flat part and a side wall part, the side wall part is located outside the flat part, and between the flat part and the side wall part Smooth transition connection through the arc-shaped part, the convex surface of the arc-shaped part faces the outer lower side, and the height of the side wall part is flush with the top surface of the groove; Step 5, electroplating the metal circuit layer on the base island in the front groove of the metal carrier plate again to form a thickened base island; Step 6: Coating bonding material or solder on the surface of the thickened base island, then implanting a chip on the bonding material or solder, and bonding metal wire between the front side of the chip and the front side of the pin; Step 7. Use plastic sealing compound to seal the metal carrier plate that has completed the chip loading and wire bonding operations in Step 6; Step 8: Remove the metal carrier plate to expose the outer surface of the pin and the thickened base island, and separate the original array-type plastic package to obtain a semiconductor package structure with the function of tin climbing on the side of the pin. 5. A manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function, characterized in that the process comprises the following steps: Step 1. Take a piece of metal carrier plate; Step 2: Paste or print a photoresist material that can be exposed and developed on the front and back of the metal carrier, and use exposure and developing equipment to expose, develop and remove part of the photoresist material on the surface of the metal carrier to expose the metal The surface of the carrier board needs to be etched pattern area; Step 3: Chemical etching is performed on the area where the exposure and development are completed on the front of the metal carrier, and the groove is formed by etching. photoresist film; Step 4, setting a copper sheet at the position of the subsequent electroplating base island in the front groove of the metal carrier; Step 5: A metal circuit layer is electroplated on the copper sheet in the front groove of the metal carrier to form a base island, and a metal circuit layer is plated on the surrounding part of the copper sheet in the front groove of the metal carrier to form a pin, and the pin includes: The plane part and the side wall part, the side wall part is located outside the plane part, the plane part and the side wall part are connected by a smooth transition through the arc part, the convex surface of the arc part faces the outer lower side, the height of the side wall part is the same as the concave part. The top surface of the groove is flush; Step 6: Coating bonding material or solder on the surface of the base island, then implanting the chip on the bonding material or solder, and bonding metal wire between the front side of the chip and the front side of the pin; Step 7. Use plastic sealing compound to seal the metal carrier plate that has completed the chip loading and wire bonding operations in Step 6; Step 8: Remove the metal carrier plate to expose the outer surfaces of the pins and the copper sheet, and separate the original array-type plastic package to obtain a semiconductor package structure with a tin-climbing function on the side of the pins. 6 . The manufacturing process of a semiconductor package structure with a pin sidewall climbing tin function according to claim 4 or 5 , wherein the potion used for etching is copper chloride or ferric chloride. 7 . 7 . The manufacturing process of a semiconductor package structure with tin-climbing function on pin sidewalls according to claim 4 or 5 , wherein the photoresist film is removed by a method of softening with chemical solution and rinsing with high pressure water. 8 . 8 . The manufacturing process of a semiconductor package structure with a pin sidewall creeping tin function according to claim 4 or 5 , wherein the metal circuit layer material is copper, aluminum or nickel. 9 . 9. The manufacturing process of a semiconductor packaging structure with a pin sidewall creeping tin function according to claim 4 or 5, wherein the material of the metal bonding wire is gold, silver, copper or aluminum; the metal bonding wire is made of gold, silver, copper or aluminum; The shape is filamentous or ribbon-like. 10. The manufacturing process of a semiconductor encapsulation structure with pin sidewall creeping tin function according to claim 4 or 5, wherein the encapsulation method of the plastic encapsulating material adopts a mold potting method, a spraying equipment spraying method or a In the method of brushing, the molding compound adopts epoxy resin with filler material or without filler material.

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