IC package lead frame structure and chip bonding method thereof

Abstract

The present invention discloses an IC package leadframe structure and die bonding method, relating to the field of semiconductor device packaging technology. This structure addresses the problem of chip bottom and die bonding island delamination caused by conventional IC packaging, where large chips require a larger die bonding island for bonding with die bonding adhesive or DAF film. The leadframe structure includes an island for mounting the chip, and an overflow adhesive step, located at the edge of the island facing the chip, to contain any excess die bonding adhesive between the chip and the island.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor device packaging, and more particularly to an IC packaging lead frame structure and a chip bonding method thereof. Background Art

[0002] In integrated circuit packaging products, traditional packaging products, most lead frame base islands are designed as a structure in which a single base island carries a single chip or multiple base islands carry multiple chips. When the chip size is larger, the lead frame base island that needs to be carried also increases accordingly. At this time, the larger chip area plus the larger base island area will cause voids, bubbles, and water vapor to be wrapped between the chip and the frame base island when using adhesive or DAF film technology to bond the chip. The water vapor cannot be discharged. When the integrated circuit is working, the heat generated by the chip will further aggravate the expansion of voids, bubbles, and water vapor and the delamination of the bottom of the chip from the adhesive layer and the frame. In severe cases, popcorn phenomenon may even occur, which will cause product failure.

[0003] Larger chip areas and larger carrier islands require more die-bonding adhesive (silver paste) to achieve secure bonding. Silver paste, a primary material in integrated circuit packaging, increases packaging costs. Traditional die-bonding processes use silver paste to bond the chip to a larger frame island than the chip. This allows ample space between the chip edge and the island edge to prevent silver paste from spilling onto the back of the frame, causing contamination and reducing product reliability.

[0004] In summary, existing IC packaging has the problem of delamination between the bottom of the chip and the base island because large chips must be fixed with a larger base island using die bonding adhesive or DAF film. Summary of the Invention

[0005] The embodiment of the present invention provides an IC package lead frame structure and a die bonding method thereof, which are used to solve the problem of delamination between the bottom of the chip and the base island caused by the need to use a larger base island to fix the large chip with die bonding glue or DAF film.

[0006] An embodiment of the present invention provides an IC package lead frame structure, including:

[0007] a base island for arranging a chip;

[0008] The glue overflow step is arranged at the edge of the base island facing the chip setting direction, and is used to set the adhesive glue overflowing from between the chip and the base island.

[0009] Preferably, it also includes a frame structure unit and a glue overflow groove;

[0010] The frame structure unit is used to set the base island;

[0011] The glue overflow groove is located between the base island and the frame structure unit, and is used to receive the die-bonding glue overflowing from between the chip and the base island.

[0012] Preferably, the base island includes a first base island and a second base island;

[0013] The first base island and the second base island are symmetrically arranged, and the chips are respectively arranged on the first base island and the second base island;

[0014] The glue overflow step is provided on an edge of the first base island facing the second base island, and the glue overflow step is provided on an edge of the second base island facing the first base island.

[0015] Preferably, the base island includes a first base island, a second base island, a third base island and a fourth base island;

[0016] The first base island, the second base island, the third base island and the fourth base island are arranged diagonally on the frame structure unit, and the chips are respectively arranged on the first base island, the second base island, the third base island and the fourth base island;

[0017] The glue overflow steps are respectively provided on the edges of the first base island, the second base island, the third base island and the fourth base island facing the chip;

[0018] The glue overflow groove is set between the first base island and the frame structure unit; the glue overflow groove is set between the second base island and the frame structure unit; the glue overflow groove is set between the third base island and the frame structure unit; and the glue overflow groove is set between the fourth base island and the frame structure unit.

[0019] Preferably, the base island is a hollow base island;

[0020] The hollow base island is composed of a frame, a hollow area and four base island connecting ribs. The four base island connecting ribs are arranged diagonally and are respectively connected to the frame. The hollow area is triangular and is located between the base island connecting ribs and the frame.

[0021] An overflow glue step is provided on the inner edge of the frame, and overflow glue steps are provided on both side edges of the base island connecting ribs;

[0022] The glue overflow groove is arranged between the outer side of the frame and the frame structure unit.

[0023] Preferably, the glue overflow groove includes a U-shaped groove or a V-shaped groove.

[0024] Preferably, the glue overflow step is formed by a stamping die; or prepared by a chemical etching method;

[0025] The height of the glue overflow step is equal to half the thickness of the frame;

[0026] The length of the glue overflow step is greater than the edge length of the chip;

[0027] The width of the glue overflow step is determined according to the diffusion degree of the adhesive.

[0028] An embodiment of the present invention provides a wafer bonding method, comprising:

[0029] A sheet adhesive is provided on the base island, wherein the base island is as described in the above embodiment;

[0030] A chip is placed on the base island by a die bonding machine, and the die bonding machine causes the die bonding adhesive placed between the base island and the chip to flow from between the base island and the chip to the adhesive overflow step.

[0031] Preferably, the method for causing the die bonding adhesive disposed between the base island and the chip to flow from between the base island and the chip to the adhesive overflow step further comprises:

[0032] Under the action of the die bonding machine, the die bonding adhesive arranged between the base island and the chip flows from between the base island and the chip to the adhesive overflow groove, and the adhesive overflow groove is located between the base island and the frame structure unit.

[0033] Preferably, a bonding adhesive is provided on the base island by a dispensing process; or

[0034] Adhesive glue is applied to the base island by a glue spraying process.

[0035] An embodiment of the present invention provides an IC package lead frame structure and a chip bonding method thereof. The lead frame structure includes: a base island, which is used to set a chip; and an overflow glue step, which is arranged at the edge of the base island in the direction of setting the chip, and is used to set the adhesive glue that overflows from between the chip and the base island. The overflow glue step is arranged at the edge of the base island, which increases the space at the edge of the base island, so that the adhesive glue that overflows from between the base island and the chip flows onto the overflow glue step, thereby preventing the adhesive glue from sticking to the edge of the base island and the back of the base island, and even affecting the reliability of the product (integrated circuit device). The IC package lead frame structure provided by the embodiment of the present invention can solve the problem of existing IC packaging where the adhesive glue easily overflows from the edge of the chip and the base island, flows to the edge of the base island or even the back of the base island, resulting in reduced product quality and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic diagram of a first IC package lead frame structure provided by an embodiment of the present invention;

[0038] Figure 2 The embodiment of the present invention provides Figure 1 The schematic diagram of the lead frame structure after the chip is installed;

[0039] Figure 3 The embodiment of the present invention provides Figure 2 Schematic diagram of cross-section structure;

[0040] Figure 4 A schematic diagram of the structure of a V-groove IC package lead frame provided by an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of the structure of an IC package lead frame with a U-shaped groove provided by an embodiment of the present invention;

[0042] Figure 6 The embodiment of the present invention provides Figure 5 The schematic diagram of the lead frame structure after the chip is installed;

[0043] Figure 7 A schematic diagram of a third IC package lead frame structure provided by an embodiment of the present invention;

[0044] Figure 8 The embodiment of the present invention provides Figure 7 The schematic diagram of the lead frame structure after the chip is installed;

[0045] Among them, 110 ~ first base island, 120 ~ second base island, 130 ~ overflow glue step, 140 ~ chip, 150 ~ overflow glue groove, 160 ~ adhesive tape, 170 ~ third base island, 180 ~ fourth base island, 190 ~ frame, 200 ~ hollow area, 210 ~ base island connecting rib. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Figure 1 A schematic diagram of a first IC package lead frame structure provided by an embodiment of the present invention; Figure 2 The embodiment of the present invention provides Figure 1 The schematic diagram of the lead frame structure after the chip is installed; Figure 3 The embodiment of the present invention provides Figure 2 Schematic diagram of cross-section structure; Figure 4 A schematic diagram of the structure of a V-groove IC package lead frame provided by an embodiment of the present invention; Figure 5 A schematic diagram of the structure of an IC package lead frame with a U-shaped groove provided by an embodiment of the present invention; Figure 6 The embodiment of the present invention provides Figure 5 The schematic diagram of the lead frame structure after the chip is installed; Figure 7 A schematic diagram of a third IC package lead frame structure provided by an embodiment of the present invention; Figure 8 The embodiment of the present invention provides Figure 7 The schematic diagram of the lead frame structure after the chip is installed is shown below; Figures 1 to 7 Taking the IC package lead frame structure provided by the embodiment of the present invention as an example, the IC package lead frame structure provided by the embodiment of the present invention is described in detail.

[0048] The IC package lead frame structure provided by an embodiment of the present invention includes a base island and a glue overflow step. Specifically, the base island is used to set the chip, and the glue overflow step is set on the base island. In actual applications, the chip is set on the base island, and the base island and the chip need to be bonded and fixed with adhesive. In order to avoid the adhesive overflowing from between the base island and the chip to the edge of the base island and the back of the base island, preferably, the glue overflow step is set at the edge of the base island facing the direction of setting the chip. Through the above arrangement, the space at the edge of the base island can be increased, so that the adhesive overflowing from between the base island and the chip flows to the glue overflow step, thereby avoiding the adhesive from causing contamination to the edge of the base island and the back of the base island, and even affecting the reliability of the lead frame.

[0049] In an embodiment of the present invention, the base island is used to set the chip. The number of base islands can be determined according to the chip size and actual application scenarios. At the same time, the position of the overflow glue step set on the base island can also be determined according to the specific combination of the chip and the base island.

[0050] For example, Figure 1 、 Figure 2 and Figure 3As shown, this embodiment provides a first IC package lead frame structure, which includes a first base island 110, a second base island 120, a glue overflow step 130 and a chip 140. The first base island 110 and the second base island 120 are arranged opposite to each other, and glue overflow steps 130 are respectively provided at two opposite edges of the first base island 110 and the second base island 120. Since the first base island 110 and the second base island 120 are used to simultaneously accommodate a chip 140, the direction in which the first base island 110 is arranged toward the chip 140 is also the direction in which the second base island 120 is arranged toward the chip 140. Correspondingly, the direction in which the second base island 120 is arranged toward the chip 140 is also the direction in which the first base island 110 is arranged. That is, the glue overflow step 130 is provided in the direction from the first base island 110 toward the second base island 120, and the glue overflow step 130 is also provided in the direction from the second base island 120 toward the first base island 110.

[0051] It should be noted that if Figure 1 As shown, the specific shapes of the first base island 110 and the second base island 120 may be different. The glue overflow step 130 provided on the first base island 110 is only located on the edge of one side of the first base island 110, while the glue overflow step 130 provided on the second base island 120 is located on the edges of three sides of the second base island 120. In the embodiment of the present invention, the specific location of the glue overflow step 130 on the base island is not limited.

[0052] In practical applications, an IC package lead frame includes multiple frame structure units. Therefore, the first IC package lead frame structure described above can be referred to as a first frame structure unit. When multiple frame structure units are arranged in a row, they can form a single-row frame; when multiple frame structure units are arranged in rows and columns, they can form a multi-row matrix lead frame.

[0053] like Figure 2 and Figure 3 As shown, after the chip 140 is set on the first base island 110 and the second base island 120, the adhesive 160 set between the chip 140 and the first base island 110 and the second base island 120 can flow out from the four sides where the chip 140 contacts the first base island 110 or the second base island 120. A part of the adhesive 160 flows on the upper surface of the base island, and the other part flows onto the adhesive overflow step 130. The adhesive overflow step 130 provided by the embodiment of the present invention can prevent the adhesive 160 from flowing from the surface of the base island to the edge of the base island and the back side of the base island.

[0054] It should be noted that, in practical applications, the length of the glue overflow step is greater than the width of the chip arranged on the base island.

[0055] The IC package lead frame structure provided in the above embodiment adopts two base islands to set the chip, that is, most of the bottom area of ​​the chip does not contact the base island, thereby reducing the adhesive layer set between the chip and the base island, reducing production costs; furthermore, a small base island is used to set the large chip, and most of the bottom area of ​​the chip is free of frame metal entities; thus, the problem of cavities and bubbles caused by the adhesive when a large chip is set on a larger base island, or bubbles and water vapor wrapped between the chip and the base island due to the DAF film and unable to be discharged is avoided; further, the problem of delamination between the bottom of the chip and the base island is avoided, thereby improving product quality and reliability.

[0056] The IC package lead frame structure provided by an embodiment of the present invention may further include a frame structure unit and a glue overflow groove. Specifically, the frame structure unit is used to position the base island; the glue overflow groove is located between the base island and the frame structure unit. In other words, the glue overflow groove is located near the edge of the base island, toward the periphery of the base island where the chip is positioned. Like the glue overflow step, the glue overflow groove is used to collect the die bonding glue that overflows from between the chip and the base island.

[0057] For example, Figure 4 、 Figure 5 and Figure 6 As shown, this embodiment provides a second IC package lead frame structure, which mainly includes a first base island 110, a second base island 120, a third base island 170, a fourth base island 180, a glue overflow step 130, a glue overflow groove 150 and a chip 140. The first base island 110, the second base island 120, the third base island 170 and the fourth base island 180 are arranged diagonally, and the first base island 110, the second base island 120, the third base island 170 and the fourth base island 180 are all arranged on the frame structure unit.

[0058] Since the first base island 110, the second base island 120, the third base island 170 and the fourth base island 180 are used to set a chip 140 at the same time, the first base island 110 is provided with glue overflow steps 130 at two edges facing the chip 140, that is, facing the diagonal direction, the second base island 120 is provided with glue overflow steps 130 at two edges facing the chip 140, that is, facing the diagonal direction, the third base island 170 is provided with glue overflow steps 130 at two edges facing the chip 140, that is, facing the diagonal direction, and the fourth base island 180 is provided with glue overflow steps 130 at two edges facing the chip 140, that is, facing the diagonal direction.

[0059] Furthermore, a glue overflow groove 150 is set in the direction of the first base island 110 away from the center of the chip 140, that is, at two edges close to the first base island 110 and the frame structure unit; a glue overflow groove 150 is set in the direction of the second base island 120 away from the center of the chip 140, that is, at two edges close to the second base island 120 and the frame structure unit; a glue overflow groove 150 is set in the direction of the third base island 170 away from the center of the chip 140, that is, at two edges close to the third base island 170 and the frame structure unit; a glue overflow groove 150 is set in the direction of the fourth base island 180 away from the center of the chip 140, that is, at two edges close to the fourth base island 180 and the frame structure unit.

[0060] It should be noted that, in practical applications, the overflow groove may include a U-shaped groove or a V-shaped groove, the difference being the different preparation methods. Figure 4 The overflow groove 150 shown is a V-shaped groove. Figure 5 The glue overflow groove 150 shown is a U-shaped groove.

[0061] In the embodiment of the present invention, there is no limitation on the specific type of the glue overflow groove provided between the base island and the frame structure unit.

[0062] The IC package lead frame structure provided in the above embodiment uses multiple small base islands to set a single large chip, so most of the bottom area of ​​the large chip is not set with adhesive, which can reduce production costs. Furthermore, the small base island is used to set the large chip, and most of the bottom area of ​​the chip is free of frame metal entities. This avoids the problem of cavities and bubbles caused by adhesive when a large chip is set on a large base island, or bubbles and water vapor wrapped between the chip and the base island due to the DAF film and cannot be discharged. Furthermore, the problem of delamination between the bottom of the chip and the base island is avoided, thereby improving product quality and reliability.

[0063] The IC package lead frame structure provided by the embodiment of the present invention can also have a hollow base island, which is composed of a frame, a hollow area and four base island connecting ribs. Figure 7 and Figure 8 As shown, this embodiment provides a third IC package lead frame structure. Four island connecting ribs 210 are arranged diagonally, with one end of each island connecting rib 210 connected to the frame 190 and the other end connected to the other ends of three other island connecting ribs 210 at the center of the hollow island. The hollow island includes four hollow areas 200, each of which has a uniform triangular shape and is located between the island connecting rib 210 and the frame 190.

[0064] In actual applications, the hollow base island is used to mount the chip 140. That is, the frame 190 and the base island connecting ribs 210 are respectively in contact with the chip 140. Therefore, a glue overflow step 130 is provided on the inner edge of the frame 190, and glue overflow steps 130 are also provided on both sides of the base island connecting ribs 210. Because the hollow base island is mounted on the frame structure unit, a glue overflow groove 150 is provided near the outer edge of the frame 190.

[0065] The IC package lead frame structure provided in the above embodiment adopts a single large base island hollow structure to set a single large chip, and most of the bottom area of ​​the large chip is not set with adhesive, which can reduce production costs; furthermore, the hollow base island is used to set the chip, and most of the bottom area of ​​the chip is free of frame metal entities; this avoids the problem of cavities and bubbles caused by adhesive or bubbles and water vapor wrapped between the chip and the base island and unable to be discharged due to the DAF film when a large chip is set on a large base island; further, the problem of delamination between the bottom of the chip and the base island is avoided, thereby improving product quality and reliability.

[0066] It should be noted that, in the embodiment of the present invention, the glue overflow step is pressed and formed by a stamping die; or prepared by a chemical etching method; in order to be able to set the maximum range of the overflow adhesive, and at the same time to enable the plastic powder particles to be effectively filled into the glue overflow step after the adhesive and the chip are set during integrated circuit packaging, preferably, the height of the glue overflow step is equal to half the thickness of the frame; the length of the glue overflow step is greater than the edge length of the set chip; the width of the glue overflow step is determined according to the diffusion degree of the adhesive.

[0067] An embodiment of the present invention further provides a die bonding method based on an IC package lead frame structure, specifically comprising the following steps:

[0068] Step 101: applying a die-bonding adhesive on a base island. The shape and structure of the base island may be determined according to the base island included in the IC package lead frame structure provided in the above embodiment.

[0069] In step 102 , a chip is placed on the base island by a die bonding machine, and the die bonding machine causes the die bonding adhesive between the base island and the chip to flow from between the base island and the chip to the adhesive overflow step.

[0070] In the above embodiment, there are three frame structures in total. The base island corresponding to each frame structure has a different structural form. Based on this, when introducing the chip bonding method, it will be introduced according to the above three frame structures respectively.

[0071] The first frame structure, such as Figure 1 、 Figure 2 and Figure 3 As shown:

[0072] In step 101, when the base island includes a first base island and a second base island, a plurality of frame structure units form a multi-row matrix frame, and a bonding adhesive is first applied to the first base island and the second base island on the plurality of frame structure units through a bonding adhesive process of a bonding machine.

[0073] It should be noted that the glue application process of the die bonding machine can be a glue dispensing process or a glue spraying process.

[0074] In step 102, a multi-row matrix frame composed of a plurality of frame structural units and provided with die bonding adhesive is transported to a die bonding position in a die bonding machine track, and the two ends of a plurality of chips are bonded to a first base island and a second base island of a plurality of frame structural units, respectively. Under the action of the bonding force of the die bonding machine, the die bonding adhesive at the relative edge positions of the first base island and the second base island is squeezed out from the edge surface where the base island and the chip are in contact, and overflows toward the side of the glue overflow step close to the inner base island surface, and at the same time overflows onto the step surface of the glue overflow step.

[0075] It should be noted that in this embodiment of the present invention, the width of the adhesive overflow step is set based on the diffusion properties of the die bonding adhesive. The height of the adhesive overflow step is equal to half the thickness of the frame, and the length of the adhesive overflow step is greater than the edge length of the chip. With this configuration, adhesive overflowing from the island surface along the height and width of the adhesive overflow step will not overflow the width of the adhesive overflow step and onto the back surface.

[0076] Furthermore, after the die bonding adhesive and chip setting are completed, the frame is automatically transferred from the die bonding machine to the lead transfer box, and then removed from the machine and taken to the oven for die bonding adhesive curing, thereby fixing the chip on the multi-row matrix frame.

[0077] The second frame structure, such as Figure 4 、 Figure 5 and Figure 6 As shown:

[0078] In step 101, when the base island includes a first base island, a second base island, a third base island and a fourth base island, a plurality of frame structure units form a multi-row matrix frame, and a bonding glue is first set on the first base island, the second base island, the third base island, and the fourth base island on the plurality of frame structure units through the glue painting process of the bonding machine.

[0079] It should be noted that the glue application process of the die bonding machine can be a glue dispensing process or a glue spraying process.

[0080] In step 102, a multi-row matrix frame composed of a plurality of frame structural units and provided with die bonding glue is transported to a die bonding position in a die bonding machine track, and the four corners of a plurality of chips are bonded to the first base island, the second base island, the third base island, and the fourth base island on the plurality of frame structural units, respectively. Under the action of the bonding force of the die bonding machine, the die bonding glue at the inner edges of the relative corner positions of the four base islands is squeezed out from the surface of the inner edges of the relative corner positions of the base islands, overflows toward the side of the glue overflow step close to the surface of the base island, and overflows onto the step surface of the glue overflow step; under the action of the bonding force of the die bonding machine, the die bonding glue at the edges of the four base islands facing the peripheral direction of the chip is squeezed out from the outer edges of the four base islands facing the peripheral direction of the chip, and flows into the glue overflow grooves provided at the edges of the base islands facing the peripheral direction of the chip, so as to prevent the die bonding glue from overflowing toward the outer edges of the base islands.

[0081] It should be noted that in this embodiment of the present invention, the width of the adhesive overflow step is set based on the diffusion properties of the die bonding adhesive. The height of the adhesive overflow step is equal to half the thickness of the frame, and the length of the adhesive overflow step is greater than the edge length of the chip. With this configuration, adhesive overflowing from the island surface along the height and width of the adhesive overflow step will not overflow the width of the adhesive overflow step and onto the back surface.

[0082] Furthermore, after the die bonding adhesive and chip setting are completed, the frame is automatically transferred from the die bonding machine to the lead transfer box, and then removed from the machine and taken to the oven for die bonding adhesive curing, thereby fixing the chip on the multi-row matrix frame.

[0083] The third frame structure, such as Figure 7 and Figure 8 As shown:

[0084] In step 101, if the base island is a hollow base island, it consists of a frame, a hollow area, and four island connecting ribs. On a multi-row matrix frame composed of several frame structural units, a die bonding machine, controlled by a pre-programmed process, uses a spray glue process to apply glue to the center of the base island and the connecting ribs of each frame structural unit, creating an "X" shape. Separately, a spray glue process is used to apply glue to the solid perimeter of the hollow base island. These two combinations create the desired die bonding adhesive shape.

[0085] In step 102, a multi-row matrix frame composed of multiple frame structural units, which has been sprayed and painted with glue, is transported to the die bonding position on the die bonding machine track. Several chips are bonded to the hollow base islands of the multiple frame structural units. Under the action of the die bonding force of the die bonding machine, the die bonding glue on the inner edge of the frame and the edges of the base island connecting ribs is squeezed out from the surface of the inner edge of the frame and the edges of the base island connecting ribs, overflowing toward the side of the glue overflow step close to the base island surface and overflowing onto the step surface of the glue overflow step. The die bonding glue squeezed out from the outer edge of the frame flows into the glue overflow groove near the edge of the frame facing the periphery of the chip, preventing the die bonding glue from overflowing toward the outer edge of the hollow base island.

[0086] Furthermore, after the die bonding adhesive and chip setting are completed, the frame is automatically transferred from the die bonding machine to the lead transfer box, and then removed from the machine and taken to the oven for die bonding adhesive curing, thereby fixing the chip on the multi-row matrix frame.

[0087] In summary, an embodiment of the present invention provides an IC package lead frame structure and a die bonding method thereof, which increases the space at the edge of the base island by setting an overflow glue step at the edge of the base island, so that the overflowed glue from between the base island and the chip flows onto the overflow glue step, thereby avoiding the die bonding glue from causing contamination to the edge of the base island and the back of the base island, and even affecting the reliability of the product. Furthermore, an overflow groove is provided near the edge of the base island in the direction of the chip periphery to prevent the adhesive from overflowing to the edge of the base island; further, the chip can be arranged by two base islands, multiple base islands, or a hollow base island, that is, most of the bottom area of ​​the chip does not contact the base island, thereby reducing the adhesive layer arranged between the chip and the base island, reducing production costs; furthermore, by adopting the hollow base island to arrange the chip, most of the bottom area of ​​the chip does not have a frame metal entity; when a large chip is arranged on a large base island, the problem of voids and bubbles caused by the adhesive or bubbles and water vapor wrapped between the chip and the base island due to the DAF film and unable to be discharged is avoided; further, the problem of delamination between the bottom of the chip and the base island is avoided, thereby improving product quality and reliability. The IC package lead frame structure provided by the embodiment of the present invention can solve the problem that the adhesive in the existing IC package easily overflows from the edge of the chip and the base island, causing the adhesive to overflow to the edge of the base island or even the back of the base island, resulting in reduced product quality and reliability.

[0088] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0089] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An IC package lead frame structure, characterized in that: include: a base island for arranging a chip; An overflow glue step is provided at an edge of the base island facing the direction in which the chip is arranged, and is used to collect the adhesive glue overflowing from between the chip and the base island; A frame structure unit, wherein the frame structure unit is used to set the base island; An overflow glue groove, located between the base island and the frame structure unit, for collecting the adhesive glue overflowing from between the chip and the base island; The base island is a hollow base island; The hollow base island is composed of a frame, a hollow area and four base island connecting ribs. The four base island connecting ribs are arranged diagonally and are respectively connected to the frame. The hollow area is triangular and is located between the base island connecting ribs and the frame. An overflow glue step is provided on the inner edge of the frame, and overflow glue steps are provided on both side edges of the base island connecting ribs; The glue overflow groove is arranged between the outer side of the frame and the frame structure unit.

2. The IC package lead frame structure according to claim 1, wherein: The base island includes a first base island and a second base island; The first base island and the second base island are symmetrically arranged, and the chips are respectively arranged on the first base island and the second base island; The glue overflow step is provided on an edge of the first base island facing the second base island, and the glue overflow step is provided on an edge of the second base island facing the first base island.

3. The IC package lead frame structure according to claim 1, wherein: The base islands include a first base island, a second base island, a third base island and a fourth base island; The first base island, the second base island, the third base island and the fourth base island are arranged diagonally on the frame structure unit, and the chips are respectively arranged on the first base island, the second base island, the third base island and the fourth base island; The glue overflow steps are respectively provided on the edges of the first base island, the second base island, the third base island and the fourth base island facing the chip; The glue overflow groove is set between the first base island and the frame structure unit; the glue overflow groove is set between the second base island and the frame structure unit; the glue overflow groove is set between the third base island and the frame structure unit; and the glue overflow groove is set between the fourth base island and the frame structure unit.

4. The IC package lead frame structure according to claim 1 or 3, wherein: The glue overflow groove includes a U-shaped groove or a V-shaped groove.

5. The IC package lead frame structure according to any one of claims 1 to 3, wherein: The glue overflow step is formed by pressing a stamping die; or prepared by a chemical etching method; The height of the glue overflow step is equal to half the thickness of the frame; The length of the glue overflow step is greater than the edge length of the chip; The width of the glue overflow step is determined according to the diffusion degree of the adhesive.

6. A die bonding method applied to the IC package lead frame structure according to any one of claims 1 to 3, characterized in that: include: Setting adhesive on the base island; A chip is placed on the base island by a die bonding machine, and the die bonding machine causes the die bonding adhesive placed between the base island and the chip to flow from between the base island and the chip to the adhesive overflow step.

7. The method for bonding sheets according to claim 6, wherein: The method of causing the die bonding adhesive disposed between the base island and the chip to flow from between the base island and the chip to the adhesive overflow step further includes: Under the action of the die bonding machine, the die bonding adhesive arranged between the base island and the chip flows from between the base island and the chip to the adhesive overflow groove, and the adhesive overflow groove is located between the base island and the frame structure unit.

8. The method for bonding sheets according to claim 7, wherein: Apply adhesive to the base island using a dispensing process; or The adhesive is applied on the base island by a spraying process.

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