CN104979303A - High-density integrated circuit package structure - Google Patents

Abstract

The invention discloses a high-density integrated circuit packaging structure, which comprises a metal lead frame composed of a lead frame base island, inner lead wires and outer leads, a chip is fixed on the lead frame base island, and the chip and the inner lead wire There is a micro-connection line between them, and the lead frame, chip and micro-connection line are sealed in a cuboid plastic package, the length A1 of the plastic package satisfies 5.13mm≤A1≤5.23mm, and the width A2 of the plastic package satisfies 5.18mm≤ A2≤5.38mm, the thickness A3 of the plastic package satisfies 1.70mm≤A3≤1.90mm; the packaging structure of the present invention can be used for small and medium scale integration with special requirements for high frequency, high bandwidth, low noise, high thermal conductivity, and high electrical conductivity The circuit overcomes the disadvantages of low circuit integration, high packaging cost and low performance of the packaging structure in the prior art.

Description

A high-density integrated circuit packaging structure

technical field

The invention belongs to the technical field of integrated circuit packaging, in particular to a high-density integrated circuit packaging structure.

Background technique

Integrated circuit packaging not only plays the role of electrical connection between the bonding points in the integrated circuit chip and the outside, but also provides a stable and reliable working environment for the integrated circuit chip, and plays a role in mechanical or environmental protection for the integrated circuit chip, so that the integration The circuit chip can perform normal functions and guarantee its high stability and reliability. In short, the quality of integrated circuit packaging has a great influence on the overall performance of integrated circuits. Therefore, the package should have strong mechanical properties, good electrical properties, heat dissipation performance and chemical stability.

Although the physical structure, application field, and I/O quantity of IC vary greatly, the role and function of IC packaging are not much different, and the purpose of packaging is quite consistent. As the "protector of the chip", packaging plays several roles, which can be summarized as follows:

(1) Protect the chip from physical damage;

(2) Redistribute the I/O to obtain a pin pitch that is easier to assemble and handle. Packaging also has other secondary functions, such as providing a structure that is easier to standardize, providing a heat dissipation path for the chip, avoiding soft errors caused by alpha particles on the chip, and providing a structure that is easier to test and burn-in. The package can also be used for the interconnection of multiple ICs.

With the continuous development of microelectromechanical systems (MEMS) devices and lab-on-chip (lab-on-chip) devices, packaging plays more roles: such as limiting the contact between the chip and the outside world, meeting the requirements of differential pressure, and meeting the chemical requirements. and atmospheric environment requirements. In recent years, people's perception of the importance and increasing functions of IC packaging has undergone a great change. IC packaging has become an area as important as IC itself. This is because in many cases, the performance of IC is affected by IC packaging constraints. Therefore, people pay more and more attention to the development of IC packaging technology to meet new challenges.

With the continuous increase of people's functional requirements for smart devices, especially the rise of smart home appliances, products need more memory. The demand for Flash Memory (flash memory) with 208mil SOP8 as the packaging carrier has risen sharply. In the past, this chip packaging market It is monopolized by companies in South Korea and Taiwan. With the rise of domestic design companies, the technical capabilities have not improved. At present, the chip design technology has been supported in China, but the packaging technology in South Korea and Taiwan is relatively mature. Plants are catching up.

At present, domestic packaging factories rarely have this kind of 208mil wide-body SOP8 packaging technology, and even if they do, the technology is not perfect and the reliability is relatively low. Taiwanese companies have accumulated many years of experience in packaging foundry, and they are relatively mature and perfect in 208mil wide-body SOP8 packaging technology, and they are in a monopoly position in the industry. Therefore, it is extremely necessary to develop this circuit packaging structure and packaging technology.

Contents of the invention

The object of the present invention is to provide a high-density integrated circuit packaging structure to address the above-mentioned deficiencies in the prior art, so as to increase the integration of circuits in the package, reduce packaging costs and improve the reliability of integrated circuit packaging.

The technical solution adopted by the present invention to solve the technical problem is: a high-density integrated circuit packaging structure, including a metal lead frame composed of a lead frame base island, inner lead wires and outer leads, and a metal lead frame is fixed on the lead frame base island. The chip has a micro-connection line between the chip and the inner lead wire, and the lead frame, the chip and the micro-connection line are sealed in a rectangular parallelepiped plastic package, and the length A1 of the plastic package satisfies 5.13mm≤A1≤5.23mm, The width A2 of the plastic package satisfies 5.18mm≤A2≤5.38mm, and the thickness A3 of the plastic package meets 1.70mm≤A3≤1.90mm.

In the high-density integrated circuit packaging structure, the span B1 of the outer pins satisfies 7.70mm≤B1≤8.10mm, the spacing B2 of the outer pins satisfies 1.250mm≤B2≤2.540mm, and the length B3 of the outer pins satisfies B3=(B1-A2)/2, the sole length A6 of the outer pin satisfies 0.60mm≤A6≤0.70mm, and the width B4 of the outer pin satisfies 0.38mm≤B4≤0.48mm.

In the high-density integrated circuit packaging structure described above, the width A2 of the plastic package is 5.28mm, the thickness A3 of the plastic package is 1.80mm, and the number B of the outer pins satisfies an integer of 6≤B≤40, and the outer The span B1 of the pins is 7.90mm, the spacing B2 of the outer pins is 1.27mm, the length B3 of the outer pins is 1.31mm, the length A6 of the soles of the outer pins is 0.65mm, and the width B4 of the outer pins is 0.415mm. The length A1 of the plastic package and the number B of the outer pins satisfy A1=5.23+(B-8)×1.8/2mm.

In the high-density integrated circuit packaging structure described above, the number B of external pins is eight, and the length A1 of the plastic package is 5.23mm.

In the high-density integrated circuit packaging structure, the back of the base island of the lead frame is provided with a plurality of conical pits arranged in an array.

Said high-density integrated circuit packaging structure has eight rectangular holes in the base island of the lead frame.

Said a kind of high-density integrated circuit packaging structure, its inner lead wire is copper wire, copper alloy wire, iron wire, iron alloy wire, aluminum wire or aluminum alloy wire, and the inner lead wire is also provided with a thickness of 17- 76um silver alloy coating, the silver alloy is composed of 1.8-2.5% of Cu, 1.2-1.5% of Ge, 1.5-2.5% of Sn, 0.8-1.2% of In and the balance of Ag.

The high-density integrated circuit packaging structure, the base island of the lead frame is made of copper, copper alloy, iron, iron alloy, aluminum or aluminum alloy, and the outer edge surface of the base island of the lead frame is plated with a ring thickness of 17-76nm The oxide layer is deposited by sputtering, and the oxide layer is composed of 45-50% indium oxide, 25-30% tin oxide, 8-10% germanium oxide and the balance of oxide Zinc composition.

Said a kind of high-density integrated circuit packaging structure, the distance from the base island of the lead frame to the top of the inner lead line is 0.203mm, the sinking distance of the base island of the lead frame is 0.203mm, and the length of the inner lead line is 0.659mm , the packaging material used in the plastic packaging body is an environmentally friendly resin molding compound.

The high-density integrated circuit packaging structure has a lead frame size of 300±0.100 mm in length, 100 mm in width and 0.203 mm in thickness, and a plurality of installation units are arranged on the lead frame, and the installation units are arranged along the width direction 11 rows, arranged in 36 rows along the length direction, a plurality of process holes are arranged in the middle of the lead frame, and the process holes include oblong holes and square holes.

The beneficial effects of the present invention are:

1. Through the size design of the length, width and height of the plastic package, this packaged integrated circuit product can be used for large devices with special requirements for high frequency, high bandwidth, low noise, high thermal conductivity, and high electrical conductivity (such as flash memory chips). The scale integrated circuit overcomes the disadvantages of low circuit integration, high packaging cost and low performance of the packaging structure in the prior art.

2. Through the design of the distance from the base island of the lead frame to the inner pin line, the electrical performance of the integrated circuit product is significantly improved, and the comprehensive effects of production efficiency, production pass rate, and cost are better; the pits on the back of the base island of the lead frame and The rectangular hole can improve the bonding strength of the sealing plastic of the base island, avoid delamination, and improve the reliability of the package.

3. In the lead frame disclosed by the present invention, the number of installation units on each piece increases by 106.25%, the area of each installation unit decreases by 21.65%, and the utilization rate of the lead frame is ≥ 71.4%, which greatly saves materials; plastic packaging production efficiency Up to ≥80,000 pieces/hour, increasing production efficiency.

4. The equipment used in the present invention is an automatic device. During plastic sealing, every two frames form a group, and the plastic sealing material is filled from the overflow in the middle, which saves the plastic sealing material to the greatest extent, and the utilization rate of the plastic sealing material is ≥ 70.0%, which increases the plastic sealing material utilization;

5. The rib cutting and forming technology used in the present invention makes the production efficiency of rib cutting and forming reach ≥ 112,000 pieces per hour, increasing the production efficiency;

6. The warp (warp) of the lead frame after plastic sealing of the present invention is below 10 mm, which enhances the reliability of the product; the humidity sensitivity level (MSL) is above level 3; the durability of the thermal expansion and contraction of the package body (TCT) is 500 times; high temperature accelerated aging test (HAST) 168 hours; high temperature service life test (HTOL) 1000 hours.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of lead frame base island of the present invention;

Fig. 3 is the schematic diagram of the front structure of the lead frame of the present invention;

Fig. 4 is a schematic structural view of the plastic package of the lead frame of the present invention.

The names of the marks are: 1—outer pin, 2—plastic package, 3—inner lead line, 4—pit, 5—lead frame base island, 6—rectangular hole, 7—lead frame, 8—process hole , 9—overflow glue tank.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 1, it is a schematic diagram of a high-density integrated circuit packaging structure of the present invention, including an outer pin 1 and a plastic package body 2, the length A1 of the plastic package body 2 satisfies the relationship 5.13mm≤A1≤5.23mm, and the length A1 of the plastic package body 2 The width A2 satisfies the relationship 5.18mm≤A2≤5.38mm, the thickness A3 of the plastic package 2 satisfies the relationship 1.70mm≤A3≤1.90mm, the span B1 of the outer pin 1 satisfies 3.123mm≤B1≤5.123mm, and the span of the outer pin 1 B1 satisfies 7.70mm≤B1≤8.10mm, the spacing B2 of outer pin 1 satisfies 1.250mm≤B2≤2.540mm, and the length B3 of outer pin 1 satisfies B3=(B1-A2)/2, that is, 1.26mm≤B3≤ 1.36mm, A6 of the outer pin 1 satisfies 0.60mm≤A6≤0.70mm, and the width B4 of the outer pin 1 meets 0.38mm≤B4≤0.48mm; through the design of the above dimensions, this packaged integrated circuit product can be used in Large-scale integrated circuits that have special requirements for high frequency, high bandwidth, low noise, high thermal conductivity, and high electrical conductivity (such as flash memory chips), overcome the low integration of packaging structures, high packaging costs, and high performance in the prior art. Lower downside.

Further, the width A2 of the plastic package 2 is 5.28mm, the thickness A3 of the plastic package 2 is 1.80mm, the number B of the outer pins 1 satisfies an integer of 6≤B≤40, and the span B1 of the outer pins 1 is 7.90mm, the spacing B2 of the outer pin 1 is 1.27mm, the length B3 of the outer pin 1 is 1.31mm, the length A6 of the sole of the outer pin 1 is 0.65mm, and the width B4 of the outer pin 1 is 0.415mm. The length A1 of the body 2 and the number B of the outer pins 1 satisfy A1=5.23+(B-8)×1.8/2mm, the number B of the outer pins 1 is eight, and the length A1 of the plastic package body 2 is 5.23mm.

As shown in Figure 2 is the structural representation of lead frame base island 5 of the present invention, chip is fixed on the lead frame base island 5, is provided with micro connecting line between chip and inner lead line 3, described lead frame 7, chip and the micro-connecting wires are sealed in the rectangular parallelepiped plastic package 2. The packaging material used in the plastic package 2 is an environmentally friendly resin molding compound. When the distance between the base island 5 of the lead frame and the inner lead line 3 is 0.203mm, the electrical performance is significantly improved, and the production The overall effect of efficiency, production pass rate, cost, etc. is better; the back of the lead frame base island 5 is provided with a plurality of conical pits 4 distributed in an array, and eight rectangular holes 6 are opened in the lead frame base island 5. The pit 4 and the rectangular hole 6 can improve the bonding strength of the sealing plastic of the base island, avoid delamination, and improve the reliability of the package.

Further, the inner lead wire 3 is copper wire, copper alloy wire, iron wire, iron alloy wire, aluminum wire or aluminum alloy wire, and the inner lead wire 3 is also provided with a silver alloy coating with a thickness of 17-76um. Wherein the silver alloy is composed of 1.8-2.5% Cu, 1.2-1.5% Ge, 1.5-2.5% Sn, 0.8-1.2% In and the rest of Ag in mass percent; the lead frame base island 5 is composed of Made of copper, copper alloy, iron, iron alloy, aluminum or aluminum alloy, the outer edge surface of the lead frame base island 5 is plated with an oxide layer with a thickness of 17-76nm, wherein the oxide layer is deposited by sputtering, and the oxide layer is formed by The mass percentage is composed of 45-50% indium oxide, 25-30% tin oxide, 8-10% germanium oxide and the rest of zinc oxide; the distance from the base island 5 of the lead frame to the top of the inner lead line 3 is 0.203 mm, the sinking distance of the base island 5 of the lead frame is 0.203 mm, and the length of the inner lead line 3 is 0.659 mm.

As shown in Figure 3, it is a schematic diagram of the front structure of the lead frame of the present invention. The length of the lead frame 7 is 300.00 ± 0.100mm, the width is 100.00 ± 0.050mm, and the thickness is 0.203mm. The lead frame 7 is provided with a plurality of installation units. The installation units are arranged in 11 rows along the width direction of the lead frame 7, and arranged in 36 rows along the length direction of the lead frame 7, forming an IDF matrix structure of 11x36. When plastic packaging, 39 chips can be packaged, and the installation units from the first row At the beginning, every two adjacent columns of installation units form a structural unit, and the structural units of the upper and lower adjacent columns are interlaced with each other. The frame substrate between the left and right of the structural unit is provided with a number of oblong holes and square process holes. 8. The step distance between adjacent installation units is 6.436mm, and the step distance between two adjacent structural units is 16.622mm. The lead frame of the present invention is compared with the size of the lead frame in the current industry, as shown in Table 1:

Table 1 lead frame of the present invention compares with existing 6 rows of lead frame sizes

project total length (mm) Overall width (mm) only/article Area (mm ² /piece) This Design Lead Frame 300.00 100.00 396 75.76 Existing 6 row lead frame 238.00 78.00 192 96.69

It can be seen from Table 1 that compared with the existing 6-row 208mil SOP8 package lead frame structure, the number of mounting units on each lead frame in this design increases by 106.25%, and the area of each mounting unit only decreases by 21.65% , saving raw materials.

As shown in Figure 4, it is a structural schematic diagram of the lead frame plastic packaging of the present invention. During plastic sealing, a square glue overflow groove 9 is provided in the middle of every two lead frames 7. The equipment used in the present invention is automatic equipment. When plastic sealing, every two frames To form a group, the plastic sealing compound is filled from the overflow in the middle, which saves the plastic sealing compound to the greatest extent.

In the lead frame structure of the present invention, there are 11 rows of lead frame units distributed, so that there are 396 lead frame units on each lead frame structure in total, which can hold 396 circuits. Calculated on the basis that each mold can produce 8 pieces of packaged lead frame structure, the number of packages that can be packaged reaches 3168.

Table 2 lead frame of the present invention and existing 6 rows of lead frame plastic packaging production efficiency contrast

project only/article Only/Model This Design Lead Frame 396 3168 Existing 6 row lead frame 192 1536

Simultaneously, the present invention will also significantly improve the utilization rate of the molding compound. At present, the amount of molding compound used for each molding of a common 6-row frame is 2598.4g/mold, while the plastic sealing method used in the present invention is 2923.2g/mold, thereby obtaining As shown in Table 3, the utilization rate of the molding compound can be increased by 13.8% by adopting the method of the present invention, thus the technical effect is obvious. Because the plastic sealing equipment adopted in the present invention is automatic equipment, it can plastic seal 12 frames per hour, and the production efficiency is as high as 36950 pieces per hour.

Table 3 Comparison of lead frame of the present invention and existing 6 rows of lead frame plastic packaging production efficiency

project Only/Model Plastic compound (g)/piece Plastic compound (g)/mold Utilization This Design Lead Frame 396 4.2 2105.6 78.9% Existing 6 row lead frame 192 4.2 1240.6 65.1%

As shown in Figure 3, it can be seen that the frame structure of the present invention is a group of every two rows, 11 rows in total, for improving productivity, adapting to the large matrix high-density production mode, a kind of rib cutting forming technology is provided, in the rib cutting method of the present invention Among them, 4 rows of frame units are punched at the same time at the same time, so that a total of 44 lead frame units are punched each time. Calculated by punching 55 times per minute, the number of punched lead frame units per minute is 2420. However, the current common 6-row lead frame punches 24 pieces each time, and punches 1320 pieces per minute, so the present invention can improve the rib cutting efficiency by 83.3%.

Compared with the prior art, the present invention has the following beneficial technical effects:

1. The utilization rate of the frame is ≥71.4%, which greatly saves materials;

2. The utilization rate of plastic sealing compound is ≥70.0%, which increases the utilization rate of plastic sealing compound;

3. The production efficiency of plastic packaging is as high as ≥80000 pieces per hour, which increases the production efficiency;

4. The production efficiency of rib cutting and forming reaches ≥112,000 pieces per hour, increasing production efficiency;

5. The warp of the lead frame after plastic sealing is less than 10mm, which enhances the reliability of the product;

6. Moisture sensitivity level (MSL) level 3 or above;

7. The thermal expansion and contraction durability (TCT) of the package is 500 times;

8. High temperature accelerated aging test (HAST) for 168 hours;

9. High temperature service life test (HTOL) 1000 hours

The above-mentioned embodiments only illustrate the principles and effects of the present invention, as well as the partially used embodiments. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, some deformations and modifications can also be made. Improvements, these all belong to the protection scope of the present invention.

Claims (10)

1. A high-density integrated circuit packaging structure, characterized in that: it includes a metal lead frame (7) composed of a lead frame base island (5), an inner lead wire (3) and an outer lead (1), and the lead frame A chip is fixed on the base island (5), and a micro-connection line is provided between the chip and the inner lead wire (3), and the lead frame (7), the chip and the micro-connection line are sealed in a rectangular parallelepiped plastic package (2) Inside, the length A1 of the plastic package (2) satisfies 5.13mm≤A1≤5.23mm, the width A2 of the plastic package (2) meets 5.18mm≤A2≤5.38mm, and the thickness A3 of the plastic package (2) meets 1.70mm≤ A3≤1.90mm. 2. A high-density integrated circuit packaging structure according to claim 1, characterized in that the span B1 of the outer pins (1) satisfies 7.70mm≤B1≤8.10mm, and the distance between the outer pins (1) B2 satisfies 1.250mm≤B2≤2.540mm, the length B3 of the outer pin (1) satisfies B3=(B1-A2)/2, the sole length A6 of the outer pin (1) satisfies 0.60mm≤A6≤0.70mm, the outer pin (1) meets the The width B4 of the pin (1) satisfies 0.38mm≤B4≤0.48mm. 3. A high-density integrated circuit packaging structure according to claim 1 or 2, characterized in that the width A2 of the plastic package (2) is 5.28mm, and the thickness A3 of the plastic package (2) is 1.80mm, The number B of the outer pins (1) satisfies an integer of 6≤B≤40, the span B1 of the outer pins (1) is 7.90 mm, the distance B2 of the outer pins (1) is 1.27 mm, and the outer pins (1) The length B3 of (1) is 1.31mm, the sole length A6 of the outer pin (1) is 0.65mm, the width B4 of the outer pin (1) is 0.415mm, and the length A1 of the plastic package (2) is the same as that of the outer pin ( 1) A1=5.23+(B-8)×1.8/2mm is satisfied between the number B. 4. A high-density integrated circuit packaging structure according to claim 3, characterized in that, the number B of the outer pins (1) is eight, and the length A1 of the plastic package (2) is 5.23mm . 5. A high-density integrated circuit packaging structure according to any one of claims 1 to 4, characterized in that the back of the lead frame base island (5) is provided with a plurality of tapered recesses arranged in an array. Pit (4). 6. A high-density integrated circuit packaging structure according to claim 5, characterized in that eight rectangular holes (6) are opened in the base island (5) of the lead frame. 7. A high-density integrated circuit packaging structure according to any one of claims 1 or 2 or 4 or 6, characterized in that, the inner lead wires (3) are copper wires, copper alloy wires, iron wire, iron alloy wire, aluminum wire or aluminum alloy wire, the inner pin wire (3) is also provided with a silver alloy coating with a thickness of 17-76um, and the silver alloy is composed of 1.8-2.5% by mass of Cu, 1.2 - Composition of 1.5% Ge, 1.5-2.5% Sn, 0.8-1.2% In and balance Ag. 8. A high-density integrated circuit packaging structure according to claim 7, characterized in that, the lead frame base island (5) is made of copper, copper alloy, iron, iron alloy, aluminum or aluminum alloy, and the lead wire The outer edge surface of the frame base island (5) is coated with an oxide layer with a thickness of 17-76nm, the oxide layer is deposited by sputtering, and the oxide layer is composed of indium oxide with a mass percentage of 45-50%, 25- It consists of 30% tin oxide, 8-10% germanium oxide and the rest zinc oxide. 9. A high-density integrated circuit packaging structure according to claim 8, characterized in that the distance from the lead frame base island (5) to the top of the inner lead line (3) is 0.203 mm, and the lead frame base The sinking distance of the island (5) is 0.203 mm, the length of the inner lead line (3) is 0.659 mm, and the packaging material used for the plastic package (2) is an environmentally friendly resin plastic packaging compound. 10. A high-density integrated circuit packaging structure according to any one of claims 1 to 8, characterized in that the size of the lead frame (7) is 300±0.100mm in length, 100±0.050mm in width and 100±0.050mm in thickness 0.203mm, multiple installation units are arranged on the lead frame (7), the installation units are arranged in 11 rows along the width direction, and 36 rows along the length direction, and a plurality of installation units are arranged in the middle of the lead frame (7) The process hole (8), the process hole (8) includes oblong holes and square holes.