阅读说明：本技术 一种覆晶封装结构及封装方法 (Flip chip packaging structure and packaging method ) 是由 石浩 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种覆晶封装结构及封装方法,其中覆晶封装结构包括柔性线路板和安装在所述柔性线路板上的倒装芯片；所述柔性线路板包括基层、设置于所述基层表面的线路层和保护层,所述柔性线路板上安装有倒装芯片的一侧具有设置在所述保护层上并向背离所述保护层的方向凸伸的阻挡体；所述阻挡体与所述倒装芯片之间设置有密封胶层。所述阻挡体的高度h不小于H-L,其中L表示阻挡体到所述倒装芯片的距离,H表示密封胶层的顶部距离所述保护层的垂直距离,通过阻挡体的设置使密封胶的流动限制在阻挡体和倒装芯片之间,从而有效的控制了密封胶层在保护层上的宽度,以及有效的控制了密封胶层的外溢。(The invention discloses a flip chip packaging structure and a packaging method, wherein the flip chip packaging structure comprises a flexible circuit board and a flip chip arranged on the flexible circuit board, the flexible circuit board comprises a base layer, a circuit layer and a protective layer, the circuit layer and the protective layer are arranged on the surface of the base layer, one side of the flexible circuit board, on which the flip chip is arranged, is provided with a barrier body which is arranged on the protective layer and protrudes in the direction away from the protective layer, a sealing glue layer is arranged between the barrier body and the flip chip, the height H of the barrier body is not less than H-L, wherein L represents the distance from the barrier body to the flip chip, H represents the vertical distance from the top of the sealing glue layer to the protective layer, and the flow of sealing glue is limited between the barrier body and the flip chip through the arrangement of the barrier body, so that the width of the sealing glue layer on the protective layer is effectively controlled, and.)

1. A flip chip package structure comprises a flexible circuit board and a flip chip arranged on the flexible circuit board; the flexible circuit board comprises a base layer, a circuit layer and a protective layer, wherein the circuit layer and the protective layer are arranged on the surface of the base layer, and the circuit layer is provided with an inner connecting area used for being connected with a flip chip and a covering area covered by the protective layer; the flexible printed circuit board is characterized in that one side of the flexible printed circuit board, which is provided with the flip chip, is provided with a blocking body which is arranged on the protective layer and protrudes in the direction back to the protective layer; a sealing adhesive layer is arranged between the barrier body and the flip chip;

the height H of the barrier is not less than H-L, where L represents the distance of the barrier to the flip chip and H represents the vertical distance of the top of the encapsulant layer from the protective layer.

2. The flip chip package structure of claim 1, wherein: the blocking body is annular and arranged around the inner connecting area.

3. The flip chip package structure of claim 2, wherein: the inner connecting area is rectangular, and the blocking body is a rectangular ring matched with the inner connecting area.

4. The flip chip package structure of claim 3, wherein: the barrier is disposed concentrically with the inner connection region.

5. The flip chip package structure of claim 1, wherein: the barrier is made of non-metal materials.

6. The flip chip package structure of claim 1, wherein: the blocking body is an anti-welding paint block arranged on the protective layer.

7. The flip chip package structure of claim 1, wherein: the sealing glue layer is a resin glue layer.

8. The flip chip package structure of claim 1, wherein: the top of the sealing adhesive layer and the top of the flip chip are located on the same horizontal plane.

9. The flip chip package structure of claim 1, wherein: the top of the barrier is no higher than the top of the flip chip.

10. A method of packaging the flip chip package structure as claimed in claims 1-9, comprising the steps of:

bonding a flip chip to the inner connection region of the wiring layer;

determining the position of the barrier in the horizontal direction of the protective layer according to the width requirement of the sealing adhesive layer on the horizontal plane;

determining the height of the blocking body by combining the vertical height from the vertex of the sealing adhesive layer to the protective layer;

and coating a solder mask forming barrier on the protective layer.

Technical Field

The invention relates to the technical field of electronic manufacturing, in particular to a flip chip packaging structure and a packaging method.

Background

With the rapid development of the electronic industry, flip chip package products have the advantages of small volume, high performance, short lead, etc., which makes the flip chip package technology become the mainstream technology in the industry. In the preparation process of the flexible circuit board for flip chip packaging, the circuit on the flexible circuit board is protected, and the short circuit phenomenon caused by dropping, scratching or oxidation of foreign objects is avoided; meanwhile, in order to achieve the welding prevention effect, a layer of protective film is required to be prepared on the surface of the circuit which is not required to be welded in the flexible circuit board, and the protective film is not required to be prepared on the circuit which is required to be welded subsequently. In the actual production process, a layer of solder mask is generally coated in a screen printing manner to serve as a protective film, and the solder mask needs to be baked and hardened after being coated on the surface of the circuit layer to realize the protective function.

The conventional flexible circuit board comprises an inner pin windowing area (I L B area) required by a welding process of a packaging manufacturer and an outer pin exposed area (O L B area) required by a welding process of a panel manufacturer, a flip chip is arranged in the inner pin windowing area, and after the flip chip is electrically connected to the flexible circuit board, glue is coated on the periphery of the flip chip to seal the windowing area and protect the connection position between the flip chip and the flexible circuit board.

Disclosure of Invention

The invention aims to provide a flexible circuit board, which solves the defects in the prior art, can effectively control the size of glue coated around a chip by arranging a blocking piece on the flexible circuit board to overflow low-grade glue materials, and can ensure the minimum height of the blocking body while ensuring the function of blocking glue so as to facilitate the forming arrangement of the blocking body.

The invention provides a flip chip packaging structure, which comprises a flexible circuit board and a flip chip arranged on the flexible circuit board; the flexible circuit board comprises a base layer, a circuit layer and a protective layer, wherein the circuit layer and the protective layer are arranged on the surface of the base layer, and the circuit layer is provided with an inner connecting area used for being connected with a flip chip and a covering area covered by the protective layer; one side of the flexible circuit board, which is provided with the flip chip, is provided with a blocking body which is arranged on the protective layer and protrudes in the direction back to the protective layer; a sealing adhesive layer is arranged between the barrier body and the flip chip;

the height H of the barrier is not less than H-L, where L represents the distance of the barrier to the flip chip and H represents the vertical distance of the top of the encapsulant layer from the protective layer.

Further, the blocking body is annular and is arranged around the inner connecting area.

Furthermore, the inner connecting area is rectangular, and the blocking body is a rectangular ring matched with the inner connecting area.

Further, the barrier is concentrically disposed with the inner connection region.

Furthermore, the barrier is made of non-metal materials.

Furthermore, the blocking body is an anti-welding paint block arranged on the protective layer.

Further, the sealant layer is a resin sealant layer.

Further, the top of the sealant layer and the top of the flip chip are located at the same horizontal plane.

Further, the top of the barrier is no higher than the top of the flip chip.

A packaging method for packaging the flip chip package structure is characterized by comprising the following steps:

bonding a flip chip to the inner connection region of the wiring layer;

determining the position of the barrier in the horizontal direction of the protective layer according to the width requirement of the sealing adhesive layer on the horizontal plane;

determining the height of the blocking body by combining the vertical height from the vertex of the sealing adhesive layer to the protective layer;

and coating a solder mask forming barrier on the protective layer.

Compared with the prior art, the blocking body is arranged on the protective layer, and the flowing of the sealant is limited between the blocking body and the flip chip through the arrangement of the blocking body, so that the width of the sealant layer on the protective layer is effectively controlled, the overflow of the sealant layer is effectively controlled, and the requirements of terminal cutting and assembling are met. Meanwhile, the minimum height of the blocking body can be accurately determined according to the requirements of the distance between the blocking body and the chip and the height of the sealing adhesive layer, the material of the blocking body is saved, and meanwhile, the blocking body is conveniently formed.

Drawings

Fig. 1 is a schematic structural diagram of a flexible circuit board in a flip chip package structure according to an embodiment of the disclosure;

fig. 2 is a schematic structural diagram of a flip chip package structure according to an embodiment of the disclosure;

FIG. 3 is a top view of FIG. 2;

fig. 4 is a schematic diagram of a process for determining the minimum height of a barrier in a flip chip package structure according to an embodiment of the present invention.

Description of reference numerals: 1-base layer, 2-circuit layer, 21-internal connection region, 22-coverage region, 3-protective layer, 4-barrier body, 5-sealant layer, 100-flexible circuit board, and 200-flip chip.

Detailed Description

The embodiments described below with reference to the drawings are illustrative only and should not be construed as limiting the invention.

The embodiment of the invention comprises the following steps: as shown in fig. 1 to 3, a flexible wiring board is disclosed, which comprises a base layer 1, a wiring layer 2 and a protective layer 3, wherein the wiring layer 2 is arranged on the surface of the base layer 1, and the wiring layer 2 is provided with an inner connection area 21 for connecting with a flip chip 200 and a covering area 22 covered by the protective layer 3. The flexible circuit board also has a blocking body 4 which is arranged on the protective layer 3 and protrudes in a direction away from the protective layer 3.

The covering region 22 is covered by the protective layer 3 to protect the wiring thereon, and the inner connection region 21 is exposed without being covered by the protective layer 3 for connection and fixation with the leads of the flip chip 200. The middle position of the inner connecting area 21 is a windowing area of the inner pin. After the flip chip 200 is mounted and fixed to the interconnection regions 21, a sealant is applied around the flip chip 200 to form a sealant layer 5 to seal the connection positions between the leads of the flip chip 200 and the interconnection regions 21.

In order to conveniently realize the coating of the sealant and control the width of the dense-layer adhesive layer 5 formed after the coating of the sealant, the barrier body 4 is creatively arranged on the protective layer 3 in the embodiment of the invention, and the flow of the sealant is limited between the barrier body 4 and the flip chip 200 by the arrangement of the barrier body 4, so that the width of the sealant layer 5 on the protective layer 3 is effectively controlled, the overflow of the sealant layer 5 is effectively controlled, and the requirements of terminal cutting and assembly are met.

The actual application of the sealant is performed one turn around the flip chip 200, so that the barrier 4 is in the form of a ring and is disposed around the inner connection region 21 in this embodiment for better control of the overflow of the sealant layer 5.

In the present embodiment, the flip chip 200 has a rectangular structure, so the inner connection region 21 formed on the wiring layer 2 has a rectangular structure, and the barrier 4 has a rectangular ring shape matching the inner connection region 21. The barrier 4 is arranged to adapt to the shape of the inner connection region 21 to enable a better fit of the inner connection region 21 and thus of the flip chip 200. In the present exemplary embodiment, the blocking body 4 is arranged concentrically with respect to the inner connecting region 21. The concentric arrangement here means that the center of the rectangle of the barrier 4 coincides with the center of the rectangle formed by the flip chip 200. The arrangement of the above-mentioned structure ensures that the blocking bodies 4 are symmetrically distributed with respect to the inner connecting area 21. Meanwhile, the direction of the long side of the rectangle of the barrier 4 coincides with the direction in which the long side of the rectangle of the inner connection region 21 extends. The arrangement of the structure enables a more regular sealant layer 5 to be formed in the sealant process, and the sealant layer 5 can occupy the space area on the protective layer 3 to the minimum after being packaged.

The blocking body 4 is made of non-metal materials. The non-metallic material can avoid the generation of static electricity. The protective layer 3 is generally made of solder mask, and the solder mask is laid on the circuit layer 2. In this embodiment, the barrier 4 may be a solder mask disposed on the protective layer 3. After the protective layer 3 is manufactured, a circle of solder mask is covered on the protective layer 3 to form a barrier 4.

In the embodiment, a flip chip package structure is further disclosed, which includes the flexible circuit board 100 and the flip chip 200 mounted on the flexible circuit board 100, and the pins of the flip chip 200 are connected to the inner connection regions 21. A sealant layer 5 is coated between the flip chip 200 and the barrier 4. The sealant layer 5 is a resin sealant layer.

In order to facilitate the setting of the blocking body 4, the height of the blocking body 4 should be made the minimum height. This not only reduces the material consumption of the barrier 4 but also facilitates the formation of the barrier 4.

The barrier 4 is disposed on the protective layer 3 and there is a certain distance L between the barrier 4 and the flip chip 200, which is generally set according to customer requirements, which distance affects the size of the finally formed sealant layer 5 and also the minimum height of the final formation of the barrier 4.

In this embodiment, the top of the barrier 4 is not higher than the top of the flip chip, and the height H of the barrier 4 satisfies the condition that H is greater than or equal to H-L, where L represents the distance from the barrier 4 to the flip chip 200, H represents the vertical distance from the top of the sealant layer 5 to the protective layer, i.e., the distance from the top of the sealant layer 5 to the plane where the protective layer 3 is located in the vertical direction.

The height H of the barrier 4 is at least H-L, so that the barrier can prevent the glue from overflowing, otherwise the glue will cross the barrier 4 and lose the function of blocking the glue, in this embodiment, in order to facilitate the coating of the sealant layer 5, the top of the sealant layer 5 is set to be at the same level as the top of the flip chip 200.

As shown in fig. 4, if there is no stopper 4 in the actual sealing process, the cross section of the sealing adhesive layer 5 after sealing forms a right triangle, and the formed sealing adhesive layer 5 will drop due to the gravity of the sealant itself, therefore, the included angle between the inclined plane and the horizontal plane in the right triangle of the cross section of the sealing adhesive layer 5 will not exceed 45 degrees, therefore, the distance between the height H and L of the stopper 4 at the time of the limit position of the inclined plane formed by the sealing adhesive layer 5 satisfies H L + H, and therefore, the height of the stopper 4 should at least reach the height of H-L in order to make the stopper 4 function as a stopper in the actual process.

Through the setting, the lowest height of the blocking body 4 can be determined according to the distance between the blocking body 4 and the flip chip 200, the lowest height of the blocking body 4 can be achieved when the glue blocking effect is achieved, the material of the blocking body 4 is saved, meanwhile, the blocking body 4 is conveniently molded, and production and manufacturing are facilitated. Since the width of the barrier 4 needs to be increased to support the height of the barrier 4 while the height of the barrier 4 is increased if the barrier 4 is provided with the solder mask, the barrier 4 takes up more space.

The invention also discloses a packaging method of the flip chip packaging structure, which comprises the following steps:

bonding the leads of the flip chip 200 to the inner leads of the inner connection region of the wiring layer 2;

determining the position of the barrier 4 in the horizontal direction of the protective layer 3 according to the width requirement of the sealant layer 5 in the horizontal plane, namely, the distance L between the barrier 4 and the flip chip 200;

determining the height of the barrier 4 according to the vertical height H from the vertex of the sealant layer 5 to the protective layer and the width of the sealant layer 5 on the horizontal plane;

the resist 4 is formed, in this embodiment by coating a solder resist on the protective layer.

The construction, features and functions of the present invention are described in detail in the embodiments illustrated in the drawings, which are only preferred embodiments of the present invention, but the present invention is not limited by the drawings, and all equivalent embodiments modified or changed according to the idea of the present invention should fall within the protection scope of the present invention without departing from the spirit of the present invention covered by the description and the drawings.