The subject matter herein generally relates to a field of semiconductor packaging, particularly relates to a fingerprint identification chip package and a method for making the fingerprint identification chip package.
Fingerprint identification technology is used in electronic devices such as display devices, attendance equipment, door locks, and so on. Since the fingerprint identification chip has a small thickness and is easily broken or damaged during the packaging process, the fingerprint identification chip is usually packaged on a substrate. The substrate may be a printed circuit board, and the fingerprint identification chip is electrically connected to the substrate. That is, the fingerprint recognition chip is packaged with the printed circuit board. Then the fingerprint identification chip packaged with the substrate is connected to a motherboard (such as a TFT substrate of a liquid crystal display device). However, the substrate makes the overall package thickness of the fingerprint identification chip thicker, which is not conducive to a thinner electronic device using the fingerprint identification chip. Therefore, there is room for improvement in the art.
Implementations of the present technology will now be described, by way of embodiments only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
The redistribution layer is a component in a semiconductor packaging, and can be used in a semiconductor packaging (especially a fan-out panel-level packaging) to electrically connect a chip to a circuit board.
The fingerprint identification chip 111 may be, for example, an optical fingerprint identification chip, a capacitive fingerprint identification chip, or an ultrasonic fingerprint identification chip. The conductive pillar 112 may be made of a metal or alloy having good conductivity, such as copper or copper alloy. The encapsulating material layer 113 may be made of a material selected from at least one of polyimide, silicone, and epoxy resin, but it is not limited thereto.
The fingerprint identification chip package 10 further includes a redistribution layer 120. The redistribution layer 120 is positioned on the packaging material layer 113 and completely covers the surface of the fingerprint identification chip 111 exposed from the packaging material layer 113. The redistribution layer 120 includes a plurality of wires 121.
The redistribution layer 120 further includes insulating material 123 that is infilled between the wires 121 so that the wires 121 are insulated from each other. The insulating material 123 may be, for example, epoxy resin, silicone, polyimide (PI), or polyparaphenylenebenzo bisoxazole (PBO), benzocyclobutene (BCB), silicon oxide or phosphosilicate glass. The insulating material 123 completely covers the wires 121, which protects the wires 121 from being damaged and does not affect signal transmission of each wire 121. In the present embodiment, the fingerprint identification chip package 10 includes only one fingerprint identification chip 111. In other embodiments, the fingerprint identification chip package 10 may include two or more fingerprint identification chips 111, and a number of the fingerprint identification chips 111 may be designed according to actual requirement.
The fingerprint identification chip package 10 further includes a plurality of pins 130. The pins 130 are positioned on a side of the packaging material layer 113 away from the redistribution layer 120. The pins 130 and the conductive pillars 112 are in a one-to-one relationship, and each pin 130 is coupled to one of the conductive pillars 112. The wires 121, the conductive pillars 112, and the pins 130 cooperate with each other to electrically connect the fingerprint identification chip 111 to an external circuit (not shown). The external circuit is used to drive the fingerprint identification chip 111 to work, such as power supply for the fingerprint identification chip 111, and the external circuit may also receive the fingerprint identification signals from the fingerprint identification chip 111. The pins 130 are made of a metal or an alloy, such as at least one of wire, tin, and silver, or an alloy including wire, tin, or silver, but not limited thereto. In this embodiment, the pin 130 has a spherical shape.
The fingerprint identification chip package 10 further includes a protective layer 140. The protective layer 140 is positioned on a side of the redistribution layer 120 away from the packaging material layer 113, and is configured to protect the redistribution layer 120. The protective layer 140 is scratch-resistant. The protective layer 140 may be made of material with a high dielectric constant, such as at least one of sapphire, glass, ceramic, quartz, acrylic, and plastic, but it is not limited thereto.
A bonding film 150 is provided between the protective layer 140 and the redistribution layer 120. The bonding film 150 is configured to bond the protective layer 140 and the redistribution layer 120 together. The material of the bonding film 150 may be a translucent adhesive not easily oxidized, such as a B-stage (B-stage) polymer adhesive or a FOW (film-over-wire) film.
The fingerprint identification chip package 10 does not need a substrate, so reduces an overall packaging thickness of the fingerprint identification chip package 10. Specifically, the overall packaging thickness of the fingerprint identification chip package 10 can be reduced to less than 1 mm.
A method for making the above fingerprint identification chip package 10 is also provided in the present disclosure.
The example method is provided by way of example, as there are a variety of ways to carry out the method. The method described below can be carried out using the configurations illustrated in
Step S1: a carrier plate 160 is provided and a plurality of fingerprint identification chips 111 are formed on the carrier plate 160 at intervals, wherein a front side of each fingerprint identification chip 111 faces the carrier plate 160, as shown in
Step S2: conductive pillars 112 are formed on the carrier plate 160, as shown in
In this embodiment, a height of the conductive pillar 112 is greater than a height of the fingerprint identification chip 111 in a thickness direction of the carrier plate 160. An end of the conductive pillar 112 away from the carrier plate 160 extends beyond an end surface of the fingerprint identification chip 111 away from the carrier plate 160. Specifically, the conductive pillar 112 may be formed by forming a columnar conductive material (for example a copper pillar) on the carrier plate 160, or may be formed by forming a metal layer on the carrier plate 160 and then patterning the metal layer to form a plurality of metal pillars.
Step S3: a packaging material layer 113 is formed on the carrier plate 160, so that the packaging material layer 113 encapsulates and embeds the fingerprint identification chip 111 and the conductive pillars 112, as shown in
Step S4: a surface of the packaging material layer 113 away from the carrier plate 160 is ground so that the surface of the packaging material layer 113 away from the carrier plate 160 is flush with the end surface of the conductive pillar 112 away from the carrier plate 160, as shown in
Step S5: As shown in
Step S6: a bonding film 150 is attached on a side of the redistribution layer 120 away from the packaging material layer 113, as shown in
Step S7: the carrier plate 160 is removed, as shown in
Step S8: a protective layer 140 is attached to a surface of the bonding film 150 away from the redistribution layer 120, as shown in
Step S9: a plurality of pins 130 is formed on a surface of the packaging material layer 113 away from the redistribution layer 120, and each pin 130 is electrically connected to one of the conductive pillars 112. After this step, a fingerprint identification chip package array 170 is obtained as shown in
Step S10: the fingerprint identification chip package array 170 is cut to obtain a plurality of fingerprint identification chip packages 10 independent from each other. Each fingerprint identification chip package 10 may include one fingerprint identification chip 111 as shown in
After cutting, the number of fingerprint identification chips 111 in each fingerprint identification chip package 10 can be adjusted according to actual needs.
Even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the plain meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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202010253921.4 | Apr 2020 | CN | national |