Patent Publication Number: US-2023163034-A1

Title: Gas-permeable package lid of chip package structure and manufacturing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 110143324, filed on Nov. 22, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to a gas-permeable package lid of a chip package structure and a manufacturing method thereof, and in particular to a gas-permeable package lid of a chip package structure having a hydrophobic gas-permeable membrane and a manufacturing method thereof. 
     Description of Related Art 
     With the rising awareness of environmental health and environmental protection, air quality monitoring has been widely implemented, and monitoring is achieved mainly through the use of gas sensors to sense the environment for a long time. In order for gas sensors to adapt to long-term operation and different environments or climates, requirements for environmental tolerance of gas sensors are gradually increasing. 
     In most of the currently commercially available gas sensors, a hydrophobic gas-permeable membrane is fixed on the gas sensor&#39;s air inlet through an adhesive after chip packaging. However, the hydrophobic gas-permeable membrane must provide a hydrophobic function, and this hydrophobic property causes poor adhesion of the adhesive. Therefore, there may be poor bonding between the commercially available gas sensor and the hydrophobic gas-permeable membrane, which affects the durability of the gas sensor. 
     SUMMARY 
     The disclosure provides a gas-permeable package lid of a chip package structure and a manufacturing method thereof, which strengthen the bonding of the hydrophobic gas-permeable membrane and improve the reliability of elements. 
     A gas-permeable package lid of a chip package structure of the disclosure includes a lid body, a through hole, and a hydrophobic gas-permeable membrane. The lid body is integrally formed. The through hole penetrates the lid body. The hydrophobic gas-permeable membrane is bonded to the lid body and shields the through hole. A part of the hydrophobic gas-permeable membrane is embedded in the lid body. 
     A manufacturing method of a gas-permeable package lid of a chip package structure of the disclosure includes the following. A hydrophobic gas-permeable membrane is provided. A packaging material in liquid state is cured into a lid body. A through hole is formed in the lid body and penetrates the lid body. The hydrophobic gas-permeable membrane shields the through hole. A plurality of positioning holes of the hydrophobic gas-permeable membrane are embedded in the lid body. A plurality of hole anchoring portions of the lid body are respectively located in the positioning hole. 
     Based on the above, in the manufacturing method of the chip package structure and the gas-permeable package lid thereof of the disclosure, since a part of the hydrophobic gas-permeable membrane is embedded in the lid body, the hydrophobic gas-permeable membrane does not fall off easily and has a simple structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic top view of a gas-permeable package lid of a chip package structure applied to the chip package structure according to an embodiment of the disclosure. 
         FIG.  2    is a schematic cross-sectional view taken along a sectional line I-I of  FIG.  1   . 
         FIG.  3    is a schematic top view of a hydrophobic gas-permeable membrane of the gas-permeable package lid of the chip package structure of  FIG.  1    at a material stage. 
         FIG.  4    is a schematic top view of the hydrophobic gas-permeable membrane of the gas-permeable package lid of the chip package structure of  FIG.  1    at a material stage according to another embodiment. 
         FIG.  5    is a schematic cross-sectional view of a gas-permeable package lid of a chip package structure applied to the chip package structure according to another embodiment of the disclosure. 
         FIGS.  6 A to  6 E  are schematic cross-sectional views of a manufacturing method of a gas-permeable package lid of a chip package structure according to an embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG.  1    is a schematic top view of a gas-permeable package lid of a chip package structure applied to the chip package structure according to an embodiment of the disclosure.  FIG.  2    is a schematic cross-sectional view taken along a sectional line I-I of  FIG.  1   . For the convenience of description, the middle section of the line I-I of  FIG.  1    is offset by a certain distance compared with the two sides, so that a through hole and a positioning hole are both shown in  FIG.  2   . Referring to  FIGS.  1  and  2   , a gas-permeable package lid  100  to which the chip package structure  50  of this embodiment is applied includes a base  52  and a chip  52 A. In this embodiment, the gas-permeable package lid  100  is assembled with the base  52  and covers the chip  52 A. The gas-permeable package lid  100  and the base  52  form a chamber C 30 . The gas-permeable package lid  100  includes a lid body  110 , a through hole H 10 , and a hydrophobic gas-permeable membrane  120 . The lid body  110  is integrally formed. The through hole H 10  penetrates the lid body  110 . 
     The hydrophobic gas-permeable membrane  120  is bonded to the lid body  110  and shields the through hole H 10 . A part of the hydrophobic gas-permeable membrane  120  is embedded in the lid body  110 . The hydrophobic gas-permeable membrane  120  of this embodiment includes a membrane body  122  and a plurality of positioning holes H 20  penetrating the membrane body  122 . The positioning holes H 20  are embedded in the lid body  110 . The chamber C 30  communicates with the outside world through the hydrophobic gas-permeable membrane  120  and the through hole H 10 . Through the function of the hydrophobic gas-permeable membrane  120 , external gas may enter the chamber C 30  and contact the chip  52 A; however, moisture and other foreign objects cannot enter the chamber C 30 . A portion of the hydrophobic gas-permeable membrane  120  is embedded in the lid body  110 . A portion of the lid body  110  is located within the positioning holes H 20 . 
     In the chip package structure  50  of this embodiment, since the lid body  110  is integrally formed, that is, when the lid body  110  is formed, a part of the hydrophobic gas-permeable membrane  120  is embedded in the lid body  110 , after the lid body  110  is formed, the hydrophobic gas-permeable membrane  120  is fixed. In this way, it may be ensured that the hydrophobic gas-permeable membrane  120  does not fall off, thereby improving the reliability of the gas-permeable package lid  100  of the chip package structure  50 . In addition, no additional process is required to fix the hydrophobic gas-permeable membrane  120 , which may reduce process and material costs. 
     In this embodiment, the through hole H 10  is located above the chip  52 A, and the hydrophobic gas-permeable membrane  120  is suspended above the chip  52 A. In this way, the chip  52 A may quickly respond to changes in the outside world. In addition, the chip  52 A of this embodiment is a semiconductor chip and may be a gas sensing chip. 
     In this embodiment, the membrane body  122  has an embedding portion  122 A embedded in the lid body  110  and a shielding portion  122 B covering the through hole H 10 . The positioning holes H 20  penetrates the embedding portion  122 A and are located on opposite sides of the shielding portion  122 B and also on opposite sides of the gas-permeable package lid  100 , so the hydrophobic gas-permeable membrane  120  is stably fixed. In this embodiment, the lid body  110  has a body portion  112  surrounding the through hole H 10  and a plurality of hole anchoring portions  114  located in the body portion  112 . These hole anchoring portions  114  are respectively located in the positioning holes H 20  of the hydrophobic gas-permeable membrane  120 . The hole anchoring portion  114  of the lid body  110  is stuck in the positioning hole H 20  of the hydrophobic gas-permeable membrane  120 , so the hydrophobic gas-permeable membrane  120  is fixed by the lid body  110 . 
     In addition, the hydrophobic gas-permeable membrane  120  of the present embodiment may further have a plurality of notches H 30 . The notch H 30  penetrates the embedding portion  122 A of the membrane body  122  and is adjacent to the edge of the membrane body  122 , and is also located at the edge of the hydrophobic gas-permeable membrane  120 . A portion of the lid body  110  passes through the notch H 30 , and the notch H 30  is embedded in the lid body  110 . On the other hand, the lid body  110  further has a plurality of notch anchoring portions  116  located in the body portion  112 . These notch anchoring portions  116  are respectively located in the notches H 30  of the hydrophobic gas-permeable membrane  120 . The notch anchoring portion  116  of the lid body  110  is stuck in the notch H 30  of the hydrophobic gas-permeable membrane  120 , thereby having the function of clamping the hydrophobic gas-permeable membrane  120  and preventing the displacement of the hydrophobic gas-permeable membrane  120 . The notches H 30  of this embodiment are located, for example, on opposite sides of the gas-permeable package lid  100 . 
     In this embodiment, the surfaces of a part of the hydrophobic gas-permeable membrane  120  around the through hole H 10  that face toward and away from the chip  52 A are both covered by the lid body  110 . In other words, the portion of the hydrophobic gas-permeable membrane  120  around the through hole H 10  is clamped from above and below by the lid body  110 . On the other hand, the embedding portion  122 A of the hydrophobic gas-permeable membrane  120  is located around the through hole H 10 , and the surfaces of the embedding portion  122 A facing toward and away from the chip  52 A are both covered by the lid body  110 , and neither the surface of the shielding portion  122 B of the hydrophobic gas-permeable membrane  120  facing toward and the chip  52 A nor the surface of the shielding portion  122 B of the hydrophobic gas-permeable membrane  120  facing away from the chip  52 A is covered by the lid body  110 . 
     In this embodiment, the hydrophobic gas-permeable membrane  120  is coated with polytetrafluoroethylene, thereby being hydrophobic and breathable. In this embodiment, the material of the gas-permeable package lid  100  is, for example, plastic. 
       FIG.  3    is a schematic top view of a hydrophobic gas-permeable membrane of the gas-permeable package lid of the chip package structure of  FIG.  1    at a material stage. 
     Referring to  FIGS.  1  and  3   , the hydrophobic gas-permeable membrane  120  of the embodiment has a larger size before being embedded in the lid body  110 . In addition to the previously described positioning hole H 20  and notch H 30 , the hydrophobic gas-permeable membrane  120  further has a plurality of openings H 40  around the periphery to for positioning in the process. After the hydrophobic gas-permeable membrane  120  is embedded in the lid body  110 , a portion of the hydrophobic gas-permeable membrane  120  which goes beyond the lid body  110  is cut off, and the opening H 40  is cut off, too. 
       FIG.  4    is a schematic top view of the hydrophobic gas-permeable membrane of the gas-permeable package lid of the chip package structure of  FIG.  1    at a material stage according to another embodiment. Referring to  FIG.  4   , a hydrophobic gas-permeable membrane  300  of this embodiment is similar to the hydrophobic gas-permeable membrane  120  of  FIG.  3   , but the difference lies in that nine hydrophobic gas-permeable membranes  120  formed in a hydrophobic gas-permeable membrane  300  as shown in  FIG.  2   , adapted for batch manufacturing. There are also a plurality of openings H 50  around the hydrophobic gas-permeable membrane  300 , which are used for positioning in the process. 
       FIG.  5    is a schematic cross-sectional view of a gas-permeable package lid of a chip package structure applied to the chip package structure according to another embodiment of the disclosure. Referring to  FIG.  5   , a chip package structure  60  of this embodiment is basically the same as the chip package structure  50  of  FIG.  2   , and only the differences between the two are described herein. A surface S 12  of a part of the hydrophobic gas-permeable membrane  120  of chip package structure  60  around a through hole H 32  that faces away from the chip  52 A is covered by the lid body  130 , and a surface S 14  of a part of the hydrophobic gas-permeable membrane  120  around the through hole H 32  that faces toward the chip  52 A is not covered by the lid body  130 . However, the other parts of the hydrophobic gas-permeable membrane  120  are still embedded in the lid body  110 , so the hydrophobic gas-permeable membrane  120  may still be firmly positioned. 
       FIGS.  6 A to  6 E  are schematic cross-sectional views of a manufacturing method of a gas-permeable package lid of a chip package structure according to an embodiment of the disclosure. The manufacturing method of a gas-permeable package lid of a chip package structure of this embodiment at least includes the steps shown in  FIG.  6 B  and  FIG.  6 D . Referring to  FIG.  6 B , the hydrophobic gas-permeable membrane  120  is provided. In this embodiment, the hydrophobic gas-permeable membrane  120  has a plurality of positioning holes H 20 . Next, referring to  FIG.  6 D , a packaging material  110 A in liquid state is cured into the lid body  110 . One through hole H 10  is formed in the lid body  110  and penetrates the lid body  110 . The hydrophobic gas-permeable membrane  120  shields the through hole H 10 . A portion of the hydrophobic gas-permeable membrane  120  having the positioning hole H 20  is embedded in the lid body  110 ; that is, the positioning hole H 20  is embedded in the lid body  110 . A portion of the lid body  110  penetrates the positioning hole H 20 ; that is, a plurality of hole anchoring portions  114  of the lid body  110  are respectively located in these positioning holes H 20 . 
     In a manufacturing method of a gas-permeable package lid of a chip package structure of this embodiment, since the hydrophobic gas-permeable membrane  120  is fixed when the lid body  110  is integrally formed, there is no need to perform additional processes to fix the hydrophobic gas-permeable membrane  120 ; therefore, process and material costs may be reduced. 
     In this embodiment, the step of curing the packaging material  110 A in liquid state into the lid body  110  and embedding the positioning hole H 20  of the hydrophobic gas-permeable membrane  120  in the lid body  110  is performing an embedded injection molding process, but the disclosure is not limited thereto. 
     An example is given below to illustrate other specific steps of the manufacturing method of a gas-permeable package lid of a chip package structure, but the disclosure is not limited thereto. Referring to  FIG.  6 A , first, a lower mold  210  is provided, and the lower mold  210  has a plurality of positioning pins  212 . Next, referring to  FIG.  6 B , the hydrophobic gas-permeable membrane  120  is positioned on the lower mold  210  by the positioning pin  212 . Specifically, the positioning pin  212  passes through the opening H 40  of the hydrophobic gas-permeable membrane  120  to position the hydrophobic gas-permeable membrane  120 . Next, referring to  FIG.  6 C , an upper mold  220  and the lower mold  210  are combined to form a molding chamber C 10  that communicates with an injection passage  222  in the upper mold  220  and the lower mold  210 . The upper mold  220  and the lower mold  210  further form a closed chamber C 20 . The closed chamber C 20  is isolated from the molding chamber C 10  and injection passage  222 . In this embodiment, the injection passage  222  is located in the upper mold  220 , but the disclosure is not limited thereto. 
     Next, referring to  FIG.  6 D , the packaging material  110 A in liquid state is injected into the molding chamber C 10  from the injection passage  222  and cured into the lid body  110 . Since the closed chamber C 20  is isolated from the molding chamber C 10  and the injection passage  222 , the packaging material  110 A does not enter the closed chamber C 20 , and the through hole H 10  is formed in the closed chamber C 20 . In addition, the packaging material  110 A injected from the injection passage  222  also passes through the positioning hole H 20 , so when the packaging material  110 A is cured into the lid body  110 , it may pass through the positioning hole H 20  to position the hydrophobic gas-permeable membrane  120 . Finally, referring to  FIG.  6 E , the lid body  110  is removed from the upper mold  220  and the lower mold  210 . 
     In summary, in the gas-permeable package lid of the chip package structure and the manufacturing method thereof of the disclosure, the hydrophobic gas-permeable membrane is embedded in the integrally formed lid body. When the lid body is formed, the hydrophobic gas-permeable membrane bonds with the lid body that the hydrophobic gas-permeable membrane may be stably positioned. An additional positioning structure is not required, and the hydrophobic breathable membrane does not fall off easily, and the process and material costs are low.