FR3009476A1 - ELECTRONIC MODULE AND METHOD OF MANUFACTURING THE SAME - Google Patents

Abstract

The invention relates to a method of manufacturing an electronic box module. The method allows selective partial molding to be performed in the following steps: securing the ribbons (13) in a predetermined area (101) on the circuit substrate (11), disposing the electronic components outside the area predetermined (101) on the circuit substrate (11), forming a molding compound (15) which encapsulates the entire circuit substrate (11) and removing the tapes (13) along the molding compound (15) deposited thereon. Then, forming an electromagnetic shielding layer (19) on the molding compound (15) and disposing an opto-electronic device (22) in the predetermined area (101) on the circuit substrate (11) can protect electronic components (21) from electromagnetic interference and avoid encapsulation of optoelectronic devices (22).

Description

BACKGROUND 1. Field of the Invention [0001] The present invention relates to an electronic module and a method of manufacturing the same; more particularly, an electronic module having a selective molding and a method of manufacturing the same. 2. BACKGROUND ART [0002] A conventional electronic module comprises a plurality of electronic components arranged on a printed circuit board. In addition, the electronic component modules may include the molding material to encapsulate the electronic components to protect them. However, certain electronic components such as connectors or optoelectronic devices are not suitable for encapsulation, for example, the CMOS image sensor (CIS), a charge coupled device (CCD), and a light emitting diode (LED). To protect certain electronic components and retain the function of other components that are unsuitable for encapsulation, a "partial molding" is then used. [0004] Conventional "partial molding" is performed using a mold cage, and the molding material is added to form the molded member. However, because of fluid adhesion, the molding material tends to form air bubbles or voids at the mold cavity or gap between the components and the circuit board. Air bubbles or voids contain moisture and in the subsequent heating process can cause a "burst" problem which results in a low rate of return. In addition, when the molding is completed by the mold cage, it must be removed. To allow removal of the mold cage, a draft angle must be maintained at the time of mold cage design.

Typically, the acute angle between the mold and the printed circuit board is about 70 degrees which reduces the overall use of the printed circuit board. In addition, whenever the configuration is different, as in the case of an irregular shape of the molding, the mold cage must be redrawn. As a result, the cost increases and the design of the mold cage becomes more complicated. SUMMARY OF THE INVENTION [0005] The present invention relates to an electronic module and a method of manufacturing the same for selectively molding electronic components. According to one embodiment of the present invention, the method comprises providing a circuit substrate. The circuit substrate includes a first surface, at least a first grounding area, and a first predetermined area disposed on the first surface. Then, a first ribbon is formed on the first predetermined zone. Then, at least one electronic component is disposed outside the first predetermined area. Then, a first molded element is formed. The first molded element covers the first ribbon and the electronic components. Then, the first molded member and the first ribbon located above the first predetermined area are removed. During a step of forming the ribbon on the predetermined area, a ribbon is fixed on the entire circuit substrate. Then, a laser is used to dig the ribbon above the grounding pad. Then, the tape outside the first predetermined area is removed, so that in the predetermined area the tape remains in place. During the step of removing the molded member, the laser may be used to dig the molded member above the grounding pad that surrounds the predetermined area. During the step of removing the molded element, the laser may be used to debark the molded element above the grounding pad. During the step of removing the ribbon above the predetermined area, the heating can be used to facilitate the process. The ribbon may be a UV ribbon. During the tape removal step above the predetermined area, the ultraviolet light may be used to illuminate the tape and be removed. The manufacturing method of the electronic module may further comprise the establishment of the optoelectronic device, connector or the like, which must not be encapsulated on the predetermined area. According to one embodiment, after removal of the tape, a masking layer is formed in the predetermined area and does not cover the grounding area and the EMI (electromagnetic interference) shielding layer is formed on the entire this and is electrically connected to the grounding range. Then, the masking layer is removed, and the optoelectronic device is disposed on the predetermined area. When the laser has dug the molded element above the grounding range, the entire area receives an EMI shielding layer. The EMI shield layer and the grounding pad are electrically connected, and the tape in the predetermined area is then removed. The opto-electronic device is then placed on the predetermined zone. The circuit substrate may further include lateral grounding pads, and the EMI shielding layer and the lateral grounding pad are electrically connected. The electronic module of the present invention may further comprise a circuit substrate, electronic components, molded elements, an EMI shielding layer, optoelectronic devices and lateral grounding pads. The circuit substrate includes a surface, a grounding pad, and a predetermined area. The predetermined area and the grounding range are disposed on the surface. The electronic components are disposed on the surface outside the predetermined area. The molded element encapsulates the electronic components and each side of the molded element and the surface form an angle of between 85 and 90 degrees. The EMI shielding layer covers the molded element, and is electrically connected to the grounding pad. The optoelectronic devices are arranged on the surface of the predetermined area. The lateral grounding range is disposed on one side of the circuit substrate, and the EMI shielding layer is electrically connected to the lateral grounding range. With the above arrangement, the manufacturing method of the electronic module can perform a selective molding without molding or complex procedure. Areas that require molding are formed without molded elements or metal coatings, so that electromagnetic interference (EMI) is avoided, and optoelectronic devices are less likely to be affected by the molded elements. In order to better understand the present invention, the following embodiments are provided at the same time as illustrations to facilitate the evaluation of the present invention; however, the accompanying drawings are provided for reference and illustration only, with no intention of using them to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DIFFERENT VIEWS OF THE DRAWINGS [0017] Figs. 1A-1E are schematic views showing the steps of manufacturing the electronic module according to an embodiment of the present invention; Figure 2 is a top view of an electronic module having an irregular area formed by a method of manufacturing an electronic module according to an embodiment of the present invention. Figures 3A-3E are sectional views showing the steps of forming the electronic module with an opto-electronic device in a predetermined area according to an embodiment of the present invention; Figures 4A-4D are sectional views showing the steps of forming the electronic module with an opto-electronic device in a predetermined area according to another embodiment of the present invention; Figure 5 is a sectional view of an electronic module that includes lateral grounding pads according to an embodiment of the present invention; and [0022] Figs. 6A-6I are sectional views showing a method of manufacturing an electronic module embodying two-side molding, according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0023] The illustrations mentioned above and the following detailed descriptions are given by way of example, in order to further explain the scope of the present invention. Other objects and advantages related to the present invention will be illustrated in the following descriptions and the accompanying drawings. FIGS. 1A, 1C and 1E are sectional views of a manufacturing method of the electronic module according to an embodiment. FIGS. 1B and 1D are top views of the method of manufacturing the electronic module according to the method of production. In this embodiment, refer to Figures 1A and 1B. The method of manufacturing an electronic module of the present invention comprises, firstly, the preparation of a circuit substrate 11. The circuit substrate 11 has a surface 12, a predetermined area 101 on the surface 12 and the Grounding range 111. The position of the grounding pad 111 may be used to define the predetermined area and the non-predetermined area. In the present embodiment, the grounding pad 111 surrounds the predetermined area, and in another embodiment, the width of the grounding pad 111 is 200 μm, but the present invention does not not limit to that. The position, shape and dimensions of the grounding pad 111 are susceptible to modification to meet different requirements. First, to form the ribbon in the predetermined area, a ribbon of appropriate size may be fixed in the predetermined area 101. Alternatively, a large piece of ribbon may be attached to the entire substrate. circuit 11, and a laser is used to dig the ribbon to the peripheral region of the predetermined area, then the ribbon portion outside the predetermined area 101 is removed, so that the ribbon 13 is is present only within the predetermined zone 101. The electronic component 21 is disposed on the surface 12 outside the predetermined zone 101. It can be arranged using mounting technology at the surface (TMS), and the electronic component 21 may be in fact another element than an optoelectronic device, such as any type of active component, or passive and the present invention is not limited to this . In this specification, the opto-electronic device refers to any component that can not be encapsulated by the mounting element, for example, a CMOS image sensor, a CCD, a light-emitting diode, a connector, a hole insert, a receptacle, or the like. In addition, reference is made to components that can be encapsulated as electronic components. Figure 2 is a top view of an electronic module having an irregular area formed by a method of manufacturing an electronic module according to an embodiment of the present invention. The predetermined area 102 of Figure 2 is irregular. The predetermined area is not limited by number, size or shape. The predetermined area is used to implant the optoelectronic device, connector or the like which should not be encapsulated by the molded member in the next process. The following implementation is adaptable to the predetermined areas 101 and 102. After the step mentioned above and illustrated in Figures 1A and 1B, such as the ribbon forming step within the area predetermined and the step of placing at least one electronic component 21, the molded element 15 is formed on the entirety of the circuit substrate 11. The molded element 15 covers the ribbon 13 along the circuit substrate 11 and the electronic components 21 outside the predetermined zone 101 and the grounding area 111. The formation of the molded element 15 is carried out by transfer molding or by injection molding. The coating of the tape 13 may overlap the grounding pad 111 or be immediately adjacent to the grounding pad 111, without overlap, and the present invention is not limited thereto. As illustrated in Figures 1C and 1D, after formation of the molded member 15, a laser is used to dig around the peripheral region of the predetermined area 101. In other words, a trench is dug along of the range 111. In one embodiment, the width of the trench is about 100 μm. The grounding pad 111 is a metal layer, and the main material of the molded member 15 may comprise resin. Because the laser absorption level is different between the grounding range 111 and the molded member 15, the grounding range 111 can act as a barrier to stopping the laser cut. However, the present invention is not limited to this approach, and any means of cutting the molded element only, not touching the circuit substrate 11, can be used. For example, a contour cut may also be used to dig the molded member 15. It will be appreciated that in the present invention a laser cut is used, and that the molded member need not provide a draft angle (e.g., about 20 degrees). Therefore, the side wall of the molded element 15 and the surface 12 form an angle α of between 85 and 90 degrees. Compared to a conventional electronic module, the angle a is closer to 90 degrees. If the ribbon is a thin film, for example, a thickness of between 20 and 50 micrometers (μm), when the ribbon 13 is removed, the molded member 15 remains on the circuit substrate 11 outside of the predetermined area. The ribbon 13 may be a thermal ribbon or a UV ribbon. If the ribbon is a thermal ribbon, it can be removed by heat. In one embodiment, it is heated to 175 ° C, and the tape is removed by any removal device, preferably by suction. If the ribbon is a UV ribbon, it can be removed with UV light, and the present invention is not limited to these two types of ribbon. In another embodiment of the present invention, the ribbon is a thick film, for example, of a thickness of 0.2 mm. When the laser has dug a trench in the molded member on the predetermined area, the laser is used to trim the molded member over the predetermined area, (i.e., the molded member above ribbon 13). In other words, after removal of the molded member 15 from the predetermined area 101, the strip 13 is then removed, so that only the molded member 15 remains on the circuit substrate 11 on the outside. of the predetermined area 101. [0033] In another embodiment of the present invention, the molded member 15 outside the predetermined area 101 is covered with the EMI shielding layer 19 and is electrically connected to the beach. 111, and the opto-electronic device 22 is disposed on the predetermined area 101. [0034] FIGS. 3A to 3E show the corresponding processes and sectional views of formation of an electronic module with an opto device. Within the present embodiment, when the ribbon 13 has been removed (as shown in FIG. 3A), a masking layer 18 is disposed on the surface 12 to the intérieu r of the predetermined area 101 and does not cover the ground (as shown in Figure 3B). The material of the masking layer 18 is not limited in that it can be easily removed. Next, an EMI shielding layer 19 is formed (as shown in FIG. 3C). The EMI shielding layer 19 may be formed by vaporization, electroless plating, or projection, and the present invention is not limited thereto since the EMI shielding layer 19 and the grounding pad 111 remain electrically connected. . In this regard, the masking layer 18 is removed, the EMI shielding layer 19 covers the molded member 15 outside the predetermined area 101 and is electrically connected to the grounding pad 111 (as shown in FIG. Figure 3D), so that the function of the EMI shield can be provided to the electronic component 21. Then, the opto-electronic device 22 is disposed within the predetermined area 101 (as shown in Figure 3E), the optoelectronic device 22 may be disposed of using the surface mount technique (TMS), and the present invention is not limited thereto. As a result, the opto-electronic device 22 is not encapsulated by the mounting member, and the opto-electronic device 22 is free of electromagnetic interference (EMI). In another embodiment of the present invention, FIGS. 4A to 4D show the corresponding processes and sectional views of formation of an electronic module with an optoelectronic device 22 within the predetermined zone. 101. In the present embodiment, when the laser has dug the molded member 15 surrounding the predetermined area 101 (as shown in FIG. 4A), the entire EMI shielding layer 19 is formed (as shown in FIG. Figure 4B). The formation of the EMI shielding layer 19 is identical to that mentioned above. The EMI shielding layer 19 must be electrically connected to the grounding pad 111. Next, the strip 13 is removed, and the molded member 15 outside the predetermined area 101 is covered with the shielding layer EMI 19 and is electrically connected to the grounding pad 111 (as shown in FIG. 4C), so that the function of the EMI shielding layer can be ensured. Then, the opto-electronic device 22 is disposed within the predetermined area 101 (as shown in Figure 4D). In practice, in situations such as when the distance between each molded member 15 or the height of the molded member 15 causes electrical disconnection of the EMI shielding layer 19 and the grounding range 111, the As shown in FIGS. 3A-3E, the embodiment can be used instead of forming the EMI shielding layer 19 directly, as shown in FIGS. 4A-4B. In addition, to increase the efficiency of protection against electromagnetic interference, the electronic module may further comprise at least one side grounding region 112 disposed on one side of the circuit substrate 11 and electrically connected to EMI shielding layer 19, as shown in Figure 5. [0037] The present invention also provides a method of manufacturing a two-sided electronic module using the above-mentioned process. Most of the details of the process can be found in the previous embodiments. Refer to Figures 6A-61. In Figure 6A, the electronic component 41 is disposed on a first surface of the circuit substrate 31 outside the predetermined area. The ribbon 33 is fixed within the predetermined zone. The grounding area 311 surrounds the predetermined area, and the side grounding area 312 is disposed around the side of the substrate 31. If the height of the electronic component 41 is relatively lower, the strip 33 attached to the first surface may be a thicker ribbon, and its thickness may be slightly greater than that of the electronic component 41. [0038] Next, the first surface of the circuit substrate 31 is formed with the molded element 35. Because the ribbon 33 is thicker, the thickness of the molded member 35 is about the same as that of the ribbon 33, so that the molded member 35 can completely encapsulate the electronic component 41, as shown in Figure 6B. In addition, since the height of the molded element 35 is the same as the ribbon 33, in the following formation of the EMI shielding layer 39, the ribbon does not need to be removed and the projection can be carried out just after. Then, the molded member 35 formed on the first surface of the circuit substrate 31 is dug, as shown in Figure 6C. For the convenience of forming the following EMI shielding layer 39, the trench is wider, allowing for easier coating. Then, the molded member 35 which has been dug on the first surface of the circuit substrate 31 is coated and is covered with an ink layer 37, as shown in Figure 6D. The ink 37 serves to prevent any contamination by dust or foreign particles on the parts it covers. The ink can be removed with a chemical solvent, and the particles on it can be removed at the same time. The layer beneath the ink layer is therefore clean. Refer to Figure 6E. The circuit substrate 31 is turned over on the other side and begins to mold the second surface of the circuit substrate 31. The second surface is opposed to the first surface. The ribbon 53 is fixed on the predetermined area on the second surface. In the embodiment, the predetermined area on the second surface surrounds the non-predetermined area. However, the shape of the predetermined area is not limited to the present invention. The grounding pad 511 may be disposed around the non-predetermined area to block laser cutting, in other words, the grounding pad 511 is implanted between the predetermined area and the area. non-predetermined. In this embodiment, the height of the electronic component 61 disposed outside the predetermined area of the second surface may be relatively higher than that of the electronic component 41 on the first surface, so that a thinner ribbon 53 can be used at the second surface for attachment to the predetermined area. It should be noted that in the present embodiment, both sides of the circuit substrate 31 (i.e., the first and the second surface) are used to describe a preferred embodiment, and the present invention is not disclosed. 'there is no limit. The height of the electronic components and the position of the predetermined area do not depend on each other. The combination of the height of the electronic component and the thickness of the ribbon is decided in conjunction with a more practical process, and may be subject to change. After the electronic component 61 has been put in place on the second surface outside the predetermined area (i.e., the non-predetermined area), the molded member 55 can be formed as the shows Figure 6F. Then, the ribbon 53 and the molded member 55 are removed and the ink 57 is formed on the predetermined area above the second surface, as shown in Figure 6G. In addition, the entire circuit substrate may be subjected to the application of the EMI shielding layer 59, and then cut to form separate modules. Alternatively, the entire circuit substrate may be cut to form separate modules, first, and then applied to the EMI shielding layer 59, so that the outside of the each separate module receives the EMI shielding layer 59, as shown in Figure 6H. Then, the ink 37, 57 is washed, and the ribbon 33 is removed. The resulting circuit substrate 31 has selective molding on both sides and each side has a complete EMI shield layer 59, respectively. Finally, the opto-electronic device 62 is disposed on the predetermined zone and the electronic module is terminated, as shown in FIG. 61. It should be noted that molding on both sides is not intended to limit the present invention. If the predetermined areas of both sides are both in the central region, a complete electromagnetic masking layer can be shared between the two sides. That is, the ink 37 and the EMI shielding layer 59 can be omitted. More specifically, the substrate is subjected to the various process steps up to that shown in Figure 6C, and the EMI shielding layer 39 is formed to cover the entire substrate to simplify the process. The above embodiments simply refer to the preferred embodiments of the present invention; however, the features thereof are in no way limited to these embodiments. Any changes, alterations, modifications conveniently contemplated by those skilled in the art are intended to be within the scope of the present invention as defined by the following claims.

Claims (10)

CLAIMS: 1. Electronic box module comprising: a circuit substrate (11) having a first assembly face (12), at least a first grounding area (111) and a first predetermined area (101), the first predetermined area (101) and the first grounding area (111) being disposed on the first assembly face (12); at least one electronic component (21) on an area of the first assembly face (12) outside the first predetermined area (101); at least one first molding compound (15) encapsulating the electronic component (21), each side wall of the first molding compound (15) opposite the first predetermined area (101) forming an angle with the first assembly face (12); ) between 85 and 90 degrees; a first electromagnetic shielding layer (19) covering the molding compound (15) and being electrically connected to the grounding pad (111). An electronic box module according to claim 1, further comprising: a second assembly face (12); at least one second grounding region (511), a second predetermined area (102), wherein the second predetermined area (102) and the second grounding area (511) are disposed on the second face assembly (12); another electronic component (61) disposed on the second assembly face (12) outside the second predetermined area (102); at least one second molding compound (55) encapsulating the electronic component (61), each side wall of the second molding compound (55) opposite the second predetermined area (102) at an angle to the second assembly face (12); ) between 85 and 90 degrees; a second electromagnetic shielding layer (59) covering the second molding compound (55) and being electrically connected to the second grounding pad (511). The electronic box module of claim 1, wherein the circuit substrate (11) further comprises at least one side grounding pad (112) disposed on one side of the circuit substrate, and the first layer of electromagnetic shielding (19) and the lateral grounding pad (112) are electrically connected. A method of manufacturing an electronic box module comprising: providing a circuit substrate (11) having a first mounting face (12), at least a first grounded range (111), and a first predetermined area (101), wherein the first predetermined area (101) and the first grounding area (111) are disposed on the first assembly face (12); attaching a first ribbon (13) to the first predetermined area (101); disposing at least one electronic component (21) on the first assembly face (12) outside the first predetermined area (101); forming a first molding compound (15) on the first assembly face (12), wherein the first molding compound (15) covers the first tape (13) and the electronic component (21); removing the first molding compound (15) on the first predetermined area (101); and removing the first ribbon (13). The method of manufacturing an electronic box module according to claim 4, further comprising: providing a circuit substrate (31) having a second mounting face (12), at least a second setting range to earth (511) and a second predetermined area (102), wherein the second predetermined area (102) and the second grounding area (511) are disposed on the second assembly face (12); attaching a second first ribbon (53) to the second predetermined zone (102); and forming a second molding compound (55) on the second assembly face (12), wherein the second molding compound (55) covers the second tape (53) and the electronic component (61); removing the second molding compound (55) on the second predetermined area (102); and removing the second ribbon (53). 6. A method of manufacturing an electronic box module according to claim 4, wherein, before the step of fixing the first ribbon on the first predetermined zone, the method comprises the following steps: the fixing of a first ribbon ( 13) integer on the entire circuit substrate (11); laser digging the first ribbon (13) on the first grounding pad (111); and removing the first ribbon (13) outside the first predetermined area (101). 7. A method of manufacturing an electronic box module according to claim 4, wherein during the step of removing the first ribbon, the first ribbon (13) is detached due to heat. A method of manufacturing an electronic box module according to claim 4, wherein the first ribbon (13) is a UV ribbon, and during the step of removing the first ribbon, ultraviolet light illuminates the first ribbon ( 13). The method of manufacturing an electronic box module according to claim 4, further comprising: disposing at least one opto-electronic element (22) on the first predetermined area (101). The method of manufacturing an electronic box module according to claim 4, wherein, after the step of removing the first strip, the method comprises the steps of: forming a first shielding layer (18) on the first predetermined area (101); forming a first electromagnetic shielding layer (19) electrically connected to the first grounding pad (111); and removing the first shielding layer (18).