TW201947723A - Quad flat non-lead package and method for enabling it to be cut which can meet the user's customized requirement for the integrated circuit chip package with sensors and improve the adaptability of QFN and terminal - Google Patents

Abstract

The present invention relates to a quad flat non-lead package (QFN) and a method for enabling it to be cut. The package includes an integrated circuit chip, a lead frame, a bonding pad, a metal wire for electrically connecting the integrated circuit chip with the bonding pad, and a package body for packaging the integrated circuit chip, the lead frame, the bonding pad and the metal wire. The integrated circuit chip is fixedly installed on the lead frame, and the bonding pad is disposed around the integrated circuit chip. The bonding pad includes non-cuttable pads and cuttable pads, both of which are electrically connected together. The non-cuttable pads are electrically connected to the integrated circuit chip via the metal wire. The cuttable pads are extended from the non-cuttable pad to the outside of the package body. The bonding pad packaged by the package body at least includes a conductive contact which can be electrically contacted by the electrical components outside the package. The position of the bonding pad is set so that the end of the cuttable pad that is not connected to the non-cuttable pad is arranged along the rectangular package boundary. The minimum cutting boundary of the package is the smallest circle that prevents the non-cuttable pad from being cut. The present invention increases the size of the bonding pad along the extension direction so that the bonding pad can be cut to meet the user's customized requirement for the integrated circuit chip packages with sensors. It is suitable for users to cut the integrated circuit chip package into the required external structure, and improve the adaptability of QFN and the terminal. The large QFN simplifies the manufacturing process, further reduces the manufacturing costs, facilitates the transportation and packaging, and makes it easier for users to customize the cutting to obtain the expected QFN.

Description

Square flat pinless package and method for enabling it to be cut

The present invention relates to an integrated circuit chip, and more particularly to a package of an integrated circuit chip and a method for implementing the same.

A quad flat non-lead package (QFN) known as QFN in the prior art includes an integrated circuit chip, a lead frame for fixedly mounting the integrated circuit chip, and a bonding pad provided around the integrated circuit chip. A metal wire for electrically connecting the integrated circuit chip and the bonding pad, and a package for packaging the integrated circuit chip, the lead frame, the bonding pad and the metal wire. Pads are usually routed along rectangular edges. The QFN of the prior art has the characteristics of small volume, and the adopted lead frame and bonding pads are beneficial to heat dissipation of the package. The lead frame has low hygroscopicity and low cost, which makes the package suitable for many applications, low production cost and short production cycle. However, because the prior art QFN uses a pinless design, the solder pads are small and directly used as the conductive contacts of the package, so that the package cannot be cut, and the user wants the external structure of the integrated circuit chip package with a sensor to be The need for customization is contradictory, making the existing technology QFN poorly adaptable to the terminal.

The technical problem to be solved by the present invention is to avoid the shortcomings of the prior art and propose a leadless square flat package QFN that can be cut, and a method for enabling the leadless square flat package QFN to be cut, which is improved by improving the pads. The adaptability of QFN meets user-defined requirements.

The present invention can solve the technical problem by adopting the following technical solutions:

Design and manufacture a square flat pinless package that can be cut, including at least one integrated circuit chip, lead frame, at least one solder pad, metal wires for electrically connecting the integrated circuit chip and solder pad, and a package The package of the integrated circuit chip, the lead frame, the bonding pad and the metal wire is described. The integrated circuit chip is fixedly mounted on a lead frame. The solder pads are arranged around the integrated circuit wafer and include an uncuttable solder pad and a dicable solder pad which are electrically connected together. The non-cuttable solder pads are electrically connected to the integrated circuit chip via a metal wire. The dicing pad extends from the non-cutting pad to the outside of the package. At least one of the bonding pads encapsulated by the package body can be electrically contacted by electrical components outside the package.

Specifically, the pad is disposed at a position where the end of the cuttable pad not connected to the non-cuttable pad is disposed along a rectangular package boundary.

From the perspective of achieving cutting, the minimum cutting boundary of the package is the smallest ring shape that can prevent the non-cuttable pads from being cut. Specifically, the connection point of the non-cuttable pad and the dicable pad is set along a layout boundary surrounded by a rectangular border, and the minimum cutting boundary of the package is a layout boundary surrounded by a rectangular border. Alternatively, the connection points of the non-cuttable pads and the dicable pads are set along a layout boundary surrounded by a rectangular edge. The minimum cutting boundary of the package is to surround all the non-cuttable pads and at least with the edges of the two non-cuttable pads. Connected by the border of the circle.

In order to obtain a cuttable area, the angle between the extension direction of the cuttable pad extending outside the package and the cutting direction in which the package can be cut is greater than 0 degrees and less than 180 degrees. Further, the included angle between the extending direction of the dicing pad extending outside the package and the cutting direction in which the package can be cut is not less than 45 degrees and not more than 135 degrees. Preferably, the extending direction of the dicing pad extending outside the package is perpendicular to the cutting direction in which the package can be cut.

As a solution for implementing the conductive contacts of the solder pad, the conductive contacts of the solder pad include at least one of a first conductive contact, a second conductive contact, a third conductive contact, and a fourth conductive contact. The first conductive contact is a conductive electric shock provided on at least one end portion of the non-cuttable pad along a cutting direction in which the package can be cut. The second conductive contact is a conductive contact provided at an end of the dicing pad in an extending direction in which the dicing pad extends to the outside of the package. The third conductive contact is a conductive contact formed at the end of the dicing pad after cutting. The fourth conductive contact is a conductive contact formed on the non-cuttable pad when the dicable pad is completely cut off.

Specifically, the lead frame includes a ring-column-shaped inner frame, a ring-column-shaped outer frame, and at least one connecting rib. The inner frame is sheathed in the outer frame, and the inner frame and the outer frame are fixed together by a connecting rib. The integrated circuit chip is fixedly mounted on the inner frame. The cuttable welding pad of the welding pad is fixedly installed on the outer frame.

Further, the integrated circuit wafer is fixedly mounted on the inner frame by a die-bonding film.

Specifically, the integrated circuit wafer includes an integrated circuit wafer and an integrated circuit die.

Specifically, the package is an epoxy injection molding compound.

The present invention can solve the technical problems by adopting the following technical solutions:

Design and manufacture a large square flat no-pin package that can be cut, including at least two square flat no-pin packages that are tiled and packaged into a plate-shaped whole. The square flat pinless package includes at least one integrated circuit chip, a lead frame, at least one solder pad, a metal wire for electrically connecting the integrated circuit chip and the solder pad, and packaging the integrated circuit chip and leads. Encapsulation of frames, pads and wires. The integrated circuit chip is fixedly mounted on a lead frame. The solder pads are arranged around the integrated circuit wafer and include an uncuttable solder pad and a dicable solder pad which are electrically connected together. The non-cuttable solder pads are electrically connected to the integrated circuit chip via a metal wire. The dicing pad extends from the non-cutting pad to the outside of the package. At least one of the bonding pads encapsulated by the package body can be electrically contacted by electrical components outside the package.

The present invention can also solve the technical problems by adopting the following technical solutions:

A method is provided for enabling a square flat pinless package to be cut. The package includes at least one integrated circuit chip, a lead frame capable of fixedly mounting the integrated circuit chip, and at least one solder pad for electrically connecting the integrated circuit. Metal wires for wafers and pads, and packages for packaging the integrated circuit wafer, lead frame, pads and metal wires. The method is to set dicable pads and non-cuttable pads for the pads; set the pads around the integrated circuit wafer, and the non-cuttable pads are electrically connected to the integrated circuit wafer by means of metal wires; The cutting pads extend toward the outside of the package body; at least one of the conductive pads that can be electrically contacted by electrical components outside the package is provided after the packaged pads.

Compared with the prior art, the technical effect of the “square flat contactless package and method for enabling it to be cut” of the present invention lies in:

The cutting pads are added along the extension direction to the outside of the package, which increases the size of the pads in the extension direction, so that the pads can be cut, and the conductive contact structure without pins is not affected by the cutting, which meets the needs of users. The customized requirements for integrated circuit chip packages with sensors are suitable for users to cut the integrated circuit chip packages into the required external structure to improve the adaptability of QFN and terminals; square flat no-pin package The large board simplifies the manufacturing process, further reduces costs, facilitates transportation and packaging, and makes it easier for users to customize cutting to obtain the expected QFN.

The following further describes the preferred embodiment in combination with the drawings.

The present invention proposes a square flat pinless package QFN 7 that can be cut. As shown in FIG. 1 and FIG. 2, the QFN 7 includes at least one integrated circuit chip 4, a lead frame 2, and at least one solder pad 1 for electrical connection. The integrated circuit wafer 4 and the metal wire 3 of the bonding pad 1, and the package 5 which encapsulates the integrated circuit wafer 4, the lead frame 2, the bonding pad 1 and the metal wire 3. The integrated circuit wafer 4 includes a integrated circuit wafer (Wafer) and an integrated circuit die (Die). The integrated circuit chip 4 is fixedly mounted on the lead frame 2. The solder pad 1 is disposed around the integrated circuit wafer 4 and includes an uncuttable solder pad 12 and a dicable solder pad 11 which are electrically connected together. The non-cuttable bonding pad 12 is electrically connected to the integrated circuit chip 4 through a metal wire 3. The dicing pad 11 extends from the non-cutting pad 12 to the outside of the package 5. At least one of the bonding pads 1 encapsulated by the package body 5 can be electrically contacted by electrical components outside the QFN.

The dicing pads 11 extend toward the outside of the package 5, increasing the size of the pads 1 in the extending direction, so that the pads 1 can be cut. Since the metal wire 3 is electrically connected to the non-cuttable solder pad 12, no matter how the cuttable solder pad 11 is cut, it will not affect the QFN non-pin conductive contact structure. The invention satisfies the user's customized needs for integrated circuit chip packages with sensors, and is suitable for users to cut the integrated circuit chip packages into the required external structure to improve the adaptability of QFN and terminals. Integrated circuit wafers with sensors such as fingerprint identification wafers, pressure detection wafers, photosensor wafers, and the like.

In order to make the package have a rectangular cross-section or a flat quadrangular prism shape, in a preferred embodiment of the present invention, the pad 1 is disposed at a position where the end of the cuttable pad 11 which is not connected to the non-cuttable pad 12 is along the rectangular package. Border C5 is set. That is, the end of the cuttable solder pad 11 is disposed along the packaging boundary C5 of the rectangular border, and the layout of the non-cuttable solder pad 12 may not be limited. In a preferred embodiment of the present invention, the non-cuttable pads 12 are also arranged around the integrated circuit wafer 2 along a rectangular edge line when viewed from a cross section.

Since the bonding pad 1 is disposed around the integrated circuit wafer 4, the cutting range of the QFN of the present invention is the outside of the non-cutting bonding pad 12. Therefore, the minimum cutting boundary of the QFN package of the present invention is the smallest ring shape that can prevent the non-cuttable pad 12 from being cut. The specific shape of the minimum cutting boundary is determined by the cutting surface.

In the preferred embodiment of the present invention, the minimum cutting boundary of the QFN is described by a four-sided cylindrical cutting surface with a rectangular sideline cross section, and a cylindrical surface with a circumferential linear cross section or an elliptic cylindrical cutting surface with an elliptical circumferential cross section. In the preferred embodiment of the present invention, as shown in FIG. 1, the connection point of the non-cuttable pad 12 and the cuttable pad 11 is set along a layout boundary C1 surrounded by a rectangular edge line. If a four-sided cylindrical shape having a rectangular edge line cross-section is used, As a cutting surface, the minimum cutting boundary of the QFN of the present invention is a layout boundary C1 surrounded by a rectangular edge. If a cylindrical surface with a circumferential cross-section or an elliptical cylinder with an elliptical cross-section is used as the cutting surface, the minimum cutting boundary of the QFN of the present invention is to enclose all the non-cuttable pads 12 and at least not A peripheral line boundary C2 inscribed in the edge of the bonding pad 12 is cut. The more non-cuttable pads 12 whose edges are inscribed on the peripheral line boundary C2, the smaller the range of the peripheral line boundary C2 is.

The angle β between the extending direction e of the dicing pad 11 extending outside the package 5 and the cutting direction s in which the QFN can be cut is greater than 0 degrees and less than 180 degrees, that is, the extending direction e and the cutting direction s should not be in line. Or not parallel.

As a practical arrangement, the included angle β between the extending direction e of the dicing pad 11 extending outside the package 5 and the cutting direction s in which the QFN can be cut is not less than 45 degrees and not more than 135 degrees.

As a more commonly used arrangement, in the preferred embodiment of the present invention, as shown in FIG. 2, the extending direction e of the dicing pad 11 extending outside the package 5 is perpendicular to the cutting direction s in which the QFN can be cut, so that the QFN has Large cutting range.

As shown in FIG. 1 and FIG. 2, in the preferred embodiment of the present invention, the cuttable pad 11 and the non-cuttable pad 12 are both columnar, and one end of each of the cuttable pad 11 and the non-cuttable pad 12 is electrically connected. Together.

Generally, the conductive contacts of the bonding pad 1 should be exposed outside the package body 5 and can be electrically contacted by electrical components outside the QFN. There are various implementation schemes. Since the QFN of the present invention can be cut, the conductive contacts of the bonding pad 1 can be more than one. The conductive contacts of the solder pad 1 of the present invention include at least one of a first conductive contact, a second conductive contact, a third conductive contact, and a fourth conductive contact. As shown in FIG. 2, the first conductive contact 121 is a conductive electric shock provided at at least one end portion of the non-cuttable pad 12 in a cutting direction s in which the QFN can be cut. As shown in FIG. 2, the second conductive contact 111 is a conductive contact 111 provided at an end of the dicing pad 11 along an extending direction e of the dicing pad 11 extending to the outside of the package 5. The third conductive contact is a conductive contact formed at the end of the dicing pad 11 after cutting. The fourth conductive contact is a conductive contact formed on the non-cuttable pad when the dicable pad is completely cut off. The first conductive contact 121 and the second conductive contact 111 can be formed after the QFN package is completed, and the third conductive contact and the fourth conductive contact should be formed after the QFN is cut.

In a preferred embodiment of the present invention, as shown in FIG. 1, the lead frame 2 includes a ring-shaped inner frame 21, a ring-shaped outer frame 22, and at least one connecting rib 23. The inner frame 21 is sheathed in the outer frame 22, and the inner frame 21 and the outer frame 22 are fixed together by a connecting rib 23. The integrated circuit chip 4 is fixedly mounted on the inner frame 21. The dicing pads 11 of the pads 1 are fixedly mounted on the outer frame 22. The outer frame 22 provides a support structure for laying the bonding pads 1 before packaging. In the preferred embodiment of the present invention, the outer frame 22 is a quadrangular ring column having a circular cross section surrounded by a rectangular side line, and the cross section of the quadrangular column surface surrounded by the inner surface of the outer frame 22 is an outer boundary C4 surrounded by a rectangular side line. When a quadrilateral cylinder having a rectangular side-line cross section is used as the cutting surface, the outer boundary C4 can be set as the maximum cutting-side boundary. When a cylindrical surface with a circumferential cross-section or an elliptical cylinder with an oval cross-section is used as the cutting surface, the circumferential or elliptical circumferential boundary C3 inscribed at the outer boundary C4 may be set as the maximum cutting circle boundary.

In a preferred embodiment of the present invention, as shown in FIG. 2, the integrated circuit wafer 4 is fixedly mounted on the inner frame 21 by means of a die attach film (Die Attach Film) 6 referred to as DAF.

In a preferred embodiment of the present invention, as shown in FIG. 1 and FIG. 2, the package 5 is an epoxy injection molding compound (EMC) for short.

Based on the above solution of the present invention, a square flat pinless package QFN 7 that can be cut is shown in FIG. 3. The present invention also provides a square flat pinless package QFN large board 8 that can be cut, including a tiled package. At least two square flat contactless packages QFN 7 in a plate-shaped unit. Tiled package refers to the packaging structure formed by laying QFN 7 on the same reference plane and laying adjacent to each other. As shown in FIGS. 1 and 2, the QFN 7 includes at least one integrated circuit chip 4, a lead frame 2, at least one bonding pad 1, a metal wire 3 for electrically connecting the integrated circuit chip 4 and the bonding pad 1, and A package 5 that packages the integrated circuit wafer 4, the lead frame 2, the bonding pads 1 and the metal wires 3. The integrated circuit chip 4 is fixedly mounted on the lead frame 2. The solder pad 1 is disposed around the integrated circuit wafer 4 and includes an uncuttable solder pad 12 and a dicable solder pad 11 which are electrically connected together. The non-cuttable bonding pad 12 is electrically connected to the integrated circuit chip 4 through a metal wire 3. The dicing pad 11 extends from the non-cutting pad 12 to the outside of the package 5. At least one of the bonding pads 1 encapsulated by the package body 5 can be electrically contacted by electrical components outside the QFN. Although each QFN 7 constituting the QFN large board 8 has its own package 5, the package 5 of each QFN 7 is substantially connected as a whole. From the realization process, each lead frame 2 should be arranged according to a pre-designed structure, and the integrated circuit chip should be fixedly installed, and the bonding pad 1 should be set around the integrated circuit chip 4 of the QFN 7 and the electrical property of the metal wire 3 should be completed. Connect, and finally use the QFN large board 8 as a unit to package all the QFN 7 integrated circuit wafers 4, lead frames 2, pads 1 and metal wires 3 at a time through the packaging process of the package 5 to make a QFN large Plate 8.

Due to the inability to cut the prior art QFN, the integrated circuit wafers using QFN are manufactured as a single piece, and are packaged in a tray provided with a wafer fixed slot, which is also called a Tray disk. The QFN of the present invention can be cut, and can be made into a QFN board 8 as shown in FIG. 3 which is easier to package and transport. Since the QFN large board 8 can form multiple QFNs 7 in a single package, the process realization is easier and the cost is lower than the existing technology. In the preferred embodiment of the present invention, as shown in FIG. 3, QFN 7 is arranged in an array structure. The QFN large board 8 shown in FIG. 3 is arranged with 12 QFN 7 in an array of 3 columns and 4 rows. The large board 8 is cut to obtain a single-chip integrated circuit wafer that meets user-customized requirements, which not only saves packaging costs compared to the prior art, but also helps meet user-customized needs. The above specific implementation solutions for QFN 7 are applicable to the QFN 7 constituting the QFN large board 8, and are not repeated here.

Based on the above-mentioned packaging structure, the present invention also proposes a method for enabling a square flat pinless package QFN to be cut. The QFN 7 includes at least one integrated circuit chip 4 and a lead frame 2 capable of fixedly mounting the integrated circuit chip 4. At least one bonding pad 1, a metal wire 3 for electrically connecting the integrated circuit chip 4 and the bonding pad 1, and a package 5 encapsulating the integrated circuit chip 4, the lead frame 2, the bonding pad 1 and the metal wire 3 . The method for enabling the QFN to be cut is to provide a dicing pad 11 and a non-cutting pad 12 for the bonding pad 1. The solder pad 1 is disposed around the integrated circuit wafer 4, and the non-cuttable solder pad 12 is electrically connected to the integrated circuit wafer 4 through the metal wire 3. The dicing pad 11 extends from the non-cutting pad 12 to the outside of the package 5, and the dicable area of the QFN is obtained by means of the dicing pad 11. The packaged solder pad 1 has at least one conductive contact capable of being electrically contacted by an electrical component outside the QFN.

1‧‧‧ pad

2‧‧‧lead frame

3‧‧‧ metal wire

4‧‧‧Integrated Circuit Chip

5‧‧‧ Package

6‧‧‧ Grain Adhesive Film

7‧‧‧QFN

8‧‧‧QFN large board

11‧‧‧ Cuttable pads

111‧‧‧ conductive contacts

12‧‧‧Uncutable Pad

121‧‧‧ conductive contacts

21‧‧‧Inner frame

22‧‧‧ Outer frame

23‧‧‧ Connecting rib

C1 ~ C5‧‧‧ border

A-A, e, s‧‧‧ directions

FIG. 1 is a schematic front view of a square flat pinless package according to the present invention and a method for enabling it to be cut;

2 is a schematic cross-sectional view in the direction of A-A marked in FIG. 1;

FIG. 3 is a schematic front view of a square flat pinless package QFN large board 8 made by the preferred embodiment.

no.

Claims (6)

A square flat pinless package that can be cut, including: At least one integrated circuit chip, lead frame, at least one solder pad, metal wires for electrically connecting the integrated circuit chip and solder pad, and a package for packaging the integrated circuit chip, lead frame, solder pad, and metal wire ; The integrated circuit chip is fixedly mounted on the lead frame; The solder pad is arranged around the integrated circuit chip, including an uncuttable pad and a dicable pad which are electrically connected together; the non-cuttable pad is electrically connected to the integrated circuit chip by means of a metal wire; The pad extends toward the outside of the package; and At least one of the bonding pads encapsulated by the package body can be electrically contacted by electrical components outside the package. The square flat pinless package capable of being cut as described in claim 1, wherein the pad is disposed at a position where the end of the cuttable pad not connected to the non-cuttable pad is disposed along the rectangular package boundary. The square flat pinless package that can be cut as described in claim 1 or 2, wherein the minimum cutting boundary of the package is the smallest ring shape that can prevent the uncut pads from being cut. The square flat, pinless package that can be cut as described in claim 3, wherein the connection point of the non-cuttable pad and the cuttable pad is set along a rectangular border line, and the minimum cutting boundary of the package is the rectangular border line A bounding layout. The square flat, pinless package that can be cut as described in claim 3, wherein the connection points of the uncuttable pads and the cuttable pads are set along a rectangular border line. The minimum cutting boundary of the package is to The cutting pad is enclosed by a circumferential line boundary which is at least inscribed with the edges of the two non-cutting pads. The square flat pinless package capable of being cut as described in claim 1 or 2, wherein the included angle between the extending direction of the dicing pad extending outside the package and the cutting direction where the package can be cut is greater than 0 degrees and less than 180 degrees.