SEMICONDUCTOR PACKAGE STRUCTURE AND METHOD FOR MANUFACTURING THE SAME
A semiconductor package structure includes a substrate, a semiconductor element, an encapsulant, an adhesion layer and a metal cap. The semiconductor element is disposed on the substrate. The encapsulant covers the semiconductor element. The adhesion layer is disposed on the encapsulant. The metal cap is attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
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The present disclosure relates to a semiconductor package structure and a semiconductor process, and more particularly to a semiconductor package structure with electromagnetic interference (EMI) shielding capability and a method for manufacturing the same.
2. Description of the Related ArtA conventional semiconductor package structure includes at least one electrical device and a solid molding compound encapsulating the electrical element. Although the molding compound is an electrically insulating material, the semiconductor package structure may suffer from EMI caused by an adjacent electrical device. For example, integrated circuits are often a source of EMI, since they couple their energy to larger objects such as heatsinks, circuit board planes and cables to radiate significantly. If EMI occurs, the semiconductor package structure does not operate normally and efficiently. This is because EMI is a disturbance that affects an electrical circuit due to electromagnetic induction or electromagnetic radiation emitted from an external source. Thus, EMI resistance or shielding is desired.
SUMMARYIn one aspect according to some embodiments, a semiconductor package structure includes a substrate, a semiconductor element, an encapsulant, an adhesion layer and a metal cap. The semiconductor element is disposed on the substrate. The encapsulant covers the semiconductor element. The adhesion layer is disposed on the encapsulant. The metal cap is attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
In another aspect according to some embodiments, a method for manufacturing a semiconductor package structure includes: (a) providing a substrate with a semiconductor element disposed thereon; and (b) providing an encapsulant, an adhesion layer and a metal cap to form the semiconductor package structure, wherein the encapsulant covers the semiconductor element, the adhesion layer is disposed on the encapsulant, the metal cap is attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
In order to enhance EMI resistance or shielding, a composite material (including metal particles and a resin) may be coated on a surface of a molding compound of a semiconductor package structure. However, an adhesion between the composite material and the molding compound is low, and the composite material has poor EMI shielding capability when shielding high frequency electromagnetic waves (e.g., higher than about 300 MHz). In addition, heat dissipation capability of the composite material is low.
To address such concern, a metal layer may be plated or sputtered on a surface of a molding compound of a semiconductor package structure. However, the metal layer is typically a single layer, and options for metals are constrained because some metals do not have suitable corresponding plating solutions. For example, iron, 45# steel, stainless steel and permalloy do not have suitable corresponding plating solutions to perform a plating or sputtering process. Further, it may be difficult to control an uniformity of a thickness of the metal layer, and the plating or sputtering process may present environmental pollution concerns. In addition, the plating or sputtering process involves time consuming procedures to form the metal layer.
To address the above concerns, embodiments of the present disclosure provide an improved semiconductor package structure and improved techniques for manufacturing the semiconductor package structure. In some embodiments, the semiconductor package structure includes an adhesion layer (e.g., a solder mask layer) for adhering a metal cap to an encapsulant of the semiconductor package structure. Thus, expanded options for a metal are available for the metal cap because the metal cap may be formed by mechanical techniques such as punching. Further, a single layer or multiple layers of metal-containing materials can be laminated to form the metal cap so as to shield high frequency electromagnetic waves (e.g., higher than about 300 MHz), low frequency electromagnetic waves (e.g., lower than about 300 MHz), or both. In addition, an uniformity of a thickness of the metal cap can be readily controlled. The method of forming the metal cap can be achieved by mechanical techniques, rather than chemical techniques such as coating, plating or sputtering, thereby presenting low environmental pollution concerns.
The semiconductor element 12 is disposed on and electrically connected to the first surface 107 of the substrate 10. In one or more embodiments, the semiconductor element 12 is an integrated circuit (IC) chip, and has an active surface 121 and a backside surface 122. The backside surface 122 of the semiconductor element 12 is adhered to the first surface 107 of the substrate 10 by an inner adhesive material 123. The active surface 121 of the semiconductor element 12 is electrically connected to the bonding pads 1021 of the first patterned circuit 102 adjacent to the first surface 107 of the substrate 10 by multiple bonding wires 124. That is, the semiconductor element 12 is mounted to the substrate 10 by wire bonding. However, the semiconductor element 12 may be mounted to the substrate 10 by flip chip bonding.
The encapsulant 14 is disposed on the first surface 107 of the substrate 10 to cover and protect the semiconductor element 12 and the bonding wires 124. In one or more embodiments, a material of the encapsulant 14 is a molding compound that includes an epoxy resin and fillers dispersed therein. The encapsulant 14 has a first surface 141 (e.g., a top surface) and a side surface 142, which is inclined at an angle different from 90° with respect to the first surface 107 of the substrate 10.
The adhesion layer 16 is disposed on the encapsulant 14, and is conformal with the encapsulant 14. That is, the adhesion layer 16 includes a first portion 161 (e.g., a top portion) and a side portion 162 to cover and in contact with the first surface 141 and the side surface 142 of the encapsulant 14, respectively. In one or more embodiments, a material of the adhesion layer 16 is a solder mask that includes a thermosetting resin or a photosetting (e.g., a photo-sensitive) resin. For example, the material of the adhesion layer 16 includes, or is formed from, a cured photo-sensitive resin that includes an interpenetrating polymer network (IPN) structure. The photo-sensitive resin includes a base resin (e.g., an acrylic resin or epoxy resin) and a photo-initiator. In one or more embodiments, the material of the adhesion layer 16 may be the same as or different from the materials of the first protection layer 105 and the second protection layer 106. In one or more embodiments, the adhesion layer 16 has a substantially consistent thickness, such as in a range of about 10 μm to about 30 μm. The side portion 162 of the adhesion layer 16 is inclined at an angle different from 90° with respect to the first surface 107 of the substrate 10.
The metal cap 18 is attached to the encapsulant 14 by the adhesion layer 16, and the metal cap 18 is conformal with the encapsulant 14. In one or more embodiments, the metal cap 18 includes a first portion 181 (e.g., a top portion), a side portion 182 and an end surface 187. The first portion 181 of the metal cap 18 is attached to the first surface 141 of the encapsulant 14 by the first portion 161 of the adhesion layer 16, and the side portion 182 of the metal cap 18 is attached to the side surface 142 of the encapsulant 14 by the side portion 162 of the adhesion layer 16. The metal cap 18 has a substantially consistent thickness, such as in a range of about 1 μm to about 10 μm; thus, the thickness of the metal cap 18 may be less than the thickness of the adhesion layer 16. The side portion 182 of the metal cap 18 is inclined at an angle different from 90° with respect to the first surface 107 of the substrate 10. The adhesion layer 16 can provide enhanced adhesion between the encapsulant 14 and the metal cap 18. A bottom surface of the metal cap 18 may be a rough surface so as to increase an adhesion force with the adhesion layer 16. Thus, the metal cap 18 can provide enhanced EMI resistance or shielding. In addition, the metal cap 18 can also provide a path for heat dissipation.
The metal cap 18 includes at least one metal layer. As shown in
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Because the metal cap 18 is formed by a physical technique such as punching, rather than by chemical techniques such as coating, plating or sputtering, the method presents a reduced pollution concern. Further, expanded options for metals can be used for the metal cap 18. In addition, an uniformity of a thickness of the metal cap 18 can be readily controlled.
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Spatial descriptions, such as “above,” “below,” “up,” “left,” “right,” “down,” “top,” “bottom,” “vertical,” “horizontal,” “side,” “higher,” “lower,” “upper,” “over,” “under,” and so forth, are indicated with respect to the orientation shown in the figures unless otherwise specified. It should be understood that the spatial descriptions used herein are for purposes of illustration only, and that practical implementations of the structures described herein can be spatially arranged in any orientation or manner, provided that the merits of embodiments of this disclosure are not deviated by such arrangement.
As used herein, the singular terms “a,” “an,” and “the” may include plural referents unless the context clearly dictates otherwise.
As used herein, the terms “approximately,” “substantially,” “substantial” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. For example, when used in conjunction with a numerical value, the terms can refer to a range of variation of less than or equal to ±10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05° For example, two numerical values can be deemed to be “substantially” the same if a difference between the values is less than or equal to ±10% of an average of the values, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, “substantially” parallel can refer to a range of angular variation relative to 0° that is less than or equal to ±10°, such as less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°. For example, a thickness being “substantially” consistent can refer to a standard deviation of less than or equal to ±10% of an average thickness, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.
Two surfaces can be deemed to be coplanar or substantially coplanar if a displacement between the two surfaces is no greater than 5 μm, no greater than 2 μm, no greater than 1 μm, or no greater than 0.5 μm.
In the description of some embodiments, a component provided “on” another component can encompass cases where the former component is directly on (e.g., in physical contact with) the latter component, as well as cases where one or more intervening components are located between the former component and the latter component.
Additionally, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified.
While the present disclosure has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations do not limit the present disclosure. It should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure as defined by the appended claims. The illustrations may not be necessarily drawn to scale. There may be distinctions between the artistic renditions in the present disclosure and the actual apparatus due to manufacturing processes and tolerances. There may be other embodiments of the present disclosure which are not specifically illustrated. The specification and drawings are to be regarded as illustrative rather than restrictive. Modifications may be made to adapt a particular situation, material, composition of matter, method, or process to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the claims appended hereto. While the methods disclosed herein have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations are not limitations of the present disclosure.
Claims
1. A semiconductor package structure, comprising:
- a substrate;
- a semiconductor element disposed on the substrate;
- an encapsulant covering the semiconductor element;
- an adhesion layer disposed on the encapsulant; and
- a metal cap attached to the encapsulant by the adhesion layer, wherein the metal cap is conformal with the encapsulant.
2. The semiconductor package structure according to claim 1, wherein a material of the encapsulant is a molding compound.
3. The semiconductor package structure according to claim 1, wherein a material of the adhesion layer is a solder mask.
4. The semiconductor package structure according to claim 1, wherein the adhesion layer is formed from a thermosetting resin or a photosetting resin.
5. The semiconductor package structure according to claim 1, wherein a material of the adhesion layer includes an interpenetrating polymer network structure.
6. The semiconductor package structure according to claim 1, wherein the metal cap includes at least one metal layer.
7. The semiconductor package structure according to claim 6, wherein a material of the metal layer is selected from a group consisting of silver, copper, gold, aluminum, zinc, brass, cadmium, nickel, phosphor bronze, iron, steel, stainless steel, and combinations thereof.
8. The semiconductor package structure according to claim 1, wherein the metal cap includes an extending portion attached to a side surface of the substrate.
9. The semiconductor package structure according to claim 8, wherein the metal cap includes a grounding pin, and the grounding pin connects to the extending portion.
10. The semiconductor package structure according to claim 1, wherein the metal cap includes at least two metal layers, and materials of the metal layers are different.
11. The semiconductor package structure according to claim 1, wherein the encapsulant includes a first surface and a side surface, the adhesion layer includes a first portion and a side portion, the metal cap includes a first portion and a side portion, the first portion of the metal cap is attached to the first surface of the encapsulant by the first portion of the adhesion layer, and the side portion of the metal cap is attached to the side surface of the encapsulant by the side portion of the adhesion layer.
12. The semiconductor package structure according to claim 1, wherein the metal cap includes a first portion and a side portion, and the first portion defines an opening to expose a portion of the adhesion layer.
13. A method for manufacturing a semiconductor package structure, comprising:
- (a) providing a substrate with a semiconductor element disposed thereon; and
- (b) providing an encapsulant, an adhesion layer and a metal cap to form the semiconductor package structure, wherein the encapsulant covers the semiconductor element, the adhesion layer is disposed on the encapsulant, the metal cap is attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
14. The method according to claim 13, further comprising:
- (c) baking the semiconductor package structure.
15. The method according to claim 13, wherein (b) includes:
- (b1) forming the encapsulant on the substrate to cover the semiconductor element;
- (b2) providing a metal foil;
- (b3) forming the adhesion layer on a surface of the metal foil;
- (b4) disposing the metal foil above the encapsulant, wherein the adhesion layer faces the encapsulant; and
- (b5) punching the metal foil to the encapsulant, so as to form the metal cap attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
16. The method according to claim 15, wherein, after (b1), the method further includes:
- (b11) curing the encapsulant.
17. The method according to claim 13, wherein (b) includes:
- (b1) providing the metal cap, wherein the metal cap defines a cavity, and the adhesion layer is disposed on the metal cap in the cavity;
- (b2) dispensing an encapsulant material in the cavity;
- (b3) disposing the substrate adjacent to the metal cap, wherein the semiconductor element faces the encapsulant material; and
- (b4) pressing the substrate to the metal cap, so that the encapsulant material covers the semiconductor element to form the encapsulant, the metal cap is attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
18. The method according to claim 13, wherein (b) includes:
- (b1) forming the encapsulant on the substrate to cover the semiconductor element;
- (b2) curing the encapsulant;
- (b3) forming the adhesion layer on a surface of the encapsulant;
- (b4) providing a metal foil;
- (b5) disposing the metal foil above the encapsulant and the adhesion layer; and
- (b6) punching the metal foil to the encapsulant, so as to form the metal cap attached to the encapsulant by the adhesion layer, and the metal cap is conformal with the encapsulant.
19. The method according to claim 18, wherein, after (b2), the method further includes:
- (b21) providing a mask defining an opening; and
- (b22) disposing the substrate in the opening of the mask;
- wherein, after (b3), the method further includes:
- (b31) removing the mask.
20. The method according to claim 13, wherein a material of the adhesion layer is a solder mask, the metal cap includes at least one metal layer, a material of the metal layer is selected from a group consisting of silver, copper, gold, aluminum, zinc, brass, cadmium, nickel, phosphor bronze, iron, steel, stainless steel, and combinations thereof.
Type: Application
Filed: Oct 20, 2016
Publication Date: Apr 26, 2018
Applicant:
Inventors: Ying-Ta CHIU (Kaohsiung), Chiu-Wen LEE (Kaohsiung), Dao-Long CHEN (Kaohsiung), Po-Hsien SUNG (Kaohsiung), Ping-Feng YANG (Kaohsiung), Kwang-Lung LIN (Kaohsiung)
Application Number: 15/299,236