CN109103265B - Photoelectric sensor packaging structure with cushion block and packaging method thereof - Google Patents

Abstract

The invention discloses a photoelectric sensor packaging structure with a cushion block and a packaging method thereof, wherein the photoelectric sensor packaging structure comprises a substrate, a glue film structure is arranged on the substrate, and a second chip is packaged in the glue film structure; the adhesive film structure is provided with a cushion block, and the cushion block is provided with a first chip; the negative electrode surface of the first chip is electrically connected with the cushion block, the positive electrode surface of the first chip faces upwards, and glass covers the positive electrode surface. The packaging requirements of the photoelectric sensor can be met, the packaging size of the existing photoelectric sensor is smaller, and the existing medical requirements are better met.

Description

A photoelectric sensor packaging structure with pads and packaging method thereof

technical field

The invention belongs to the technical field of packaging of optical heart rate sensors, and relates to a packaging structure of a photoelectric sensor with pads and a packaging method of the photoelectric sensor.

Background technique

Cardiovascular disease is the primary disease that currently threatens human health, and the pulse wave of the human body reflects the function of the cardiovascular system. The body's physiology, mental state, physical strength level and other information reflected by the intensity, speed and rhythm of the pulse wave can display personal health status, or serve as auxiliary monitoring for other medical instruments, and provide diagnostic reference for doctors, etc.

Currently, pulse wave monitoring methods mainly use photoplethysmography (PPG) or the principle of piezoelectric sensors to indirectly reflect changes in pulse waves. Photoplethysmography uses the light absorption of hemoglobin in the blood to change the light intensity of a light-emitting diode (LED) irradiated on the skin, and indirectly obtains the pulse wave waveform by measuring the light reflected by the skin. Another piezoelectric induction method causes fluctuations in the skin through pulse fluctuations. Since the distance between the sensor and the skin is very small, when the skin fluctuates, it will cause fluctuations in the air between the pressure element and the piezoelectric film, and then act on the piezoelectric film to generate electricity. Signal, so that the mechanical fluctuations of the pulse are converted into changes in electrical signals.

Contents of the invention

The invention provides a photoelectric sensor packaging structure and a packaging method with pads; it can meet the packaging requirements of the photoelectric sensor, and make the existing photoelectric sensor package smaller in size, simpler in structure, low in cost, and better to meet existing medical needs.

The technical solution of the present invention is: a photoelectric sensor packaging structure with pads, a substrate, an adhesive film layer is arranged on the substrate, and a second chip is packaged inside the adhesive film layer; pads are arranged on the adhesive film layer, and the pads The first chip is arranged on the top; the negative electrode surface of the first chip is electrically connected to the pad, the positive electrode surface of the first chip faces upward, and the positive electrode surface is covered with glass; one side of the second chip is bonded to the substrate, and the other One side is electrically connected to the substrate through a metal conductor; one side of the pad is a conductive layer, and the other side is connected to the adhesive film layer; the conductive layer is arranged upward to contact with the negative electrode surface of the first chip; the adhesive film layer is arranged downward, and the glue The film layer completely wraps the second chip, and the thickness of the adhesive film layer is greater than the thickness of the second chip; the positive surface of the first chip is electrically connected to the substrate through a metal conductor; the pad is electrically connected to the first chip One side is also electrically connected to the substrate through a metal conductor; the substrate is packaged with a plastic-encapsulated structure, the plastic-encapsulated structure wraps the film layer, spacers, the first chip and the glass, and the top surface of the plastic-encapsulated structure is flush with the upper surface of the glass flat, and the upper surface of the glass is exposed.

Furthermore, the present invention is characterized in that:

Wherein the positive electrode surface of the first chip has a sensing area and a non-sensing area; the glass covers the sensing area; the non-sensing area is electrically connected to the substrate through several metal conductors.

One side of the spacer is plated with a metal layer, and the negative side of the first chip is electrically connected to the metal layer.

Wherein the negative electrode surface of the first chip is arranged on the spacer through the conductive silver paste.

The metal layer is electrically connected to the substrate through a metal conductor.

Another technical feature of the present invention is: a kind of packaging method of photoelectric sensor, comprises the following steps:

Step S1, bonding one side of the second chip on the substrate, and electrically connecting the other side of the second chip through a metal conductor; the first chip is a control processing chip;

Step S2, place the pad on the top of the second chip, the side of the pad opposite to the second chip is provided with an adhesive film layer, the adhesive film layer is an FOD adhesive film, and the adhesive film layer completely wraps the second chip, the adhesive film layer The thickness is greater than the thickness of the second chip;

Step S3, the upward side of the spacer is coated with a metal layer, the metal layer is electrically connected to the negative electrode surface of the first chip, and a metal conductor is connected between this surface of the spacer and the substrate, and the metal conductor makes the first chip The negative electrode surface of one chip is electrically connected to the substrate; the first chip is an optical sensor chip;

In step S4, the positive side of the first chip faces upwards, and the positive side includes a sensing area and a non-sensing area. The glass is bonded to the sensing area with an adhesive, and the non-sensing area is electrically connected to the substrate through a metal conductor. connect;

Step S5, wrapping the adhesive film layer, spacer, first chip and glass on the substrate with a plastic sealing compound to form a plastic sealing structure, and the upper surface of the plastic sealing structure is flush with the upper surface of the glass, and the upper surface of the glass is exposed;

In step S7, the above-mentioned photoelectric sensor packaging structure with pads is obtained.

Furthermore, the present invention is characterized in that:

The four sides of the adhesive film layer in step S are respectively flush with the four sides of the spacer 3 .

Wherein the four sides of the plastic encapsulation structure are respectively flush with the four sides of the substrate.

Compared with the prior art, the beneficial effect of the present invention is: the glass is passed to the photoelectric sensor in the packaging structure, and the glass, the first chip, the spacer, the adhesive film layer and the second chip are packaged through the packaging structure, and The second chip and the first chip are connected to the substrate through the metal conductor to realize the information interaction between the photoelectric sensor chip and the control processing chip, and the spacer is used to realize the isolation between the photoelectric sensor chip and the control processing chip.

Furthermore, the glass only needs to cover the sensing area on the positive side of the photosensor chip, and the non-sensing area is used for connecting the substrate.

Furthermore, a metal layer is plated on the spacer, and the negative electrode surface of the photoelectric sensor is connected to the substrate through the metal layer.

Furthermore, the FOD process is used to wrap the second chip control processing chip, which effectively reduces the size of the entire package and can better meet the needs of end customers. This structure has a simple packaging process and effectively controls production costs.

Description of drawings

Fig. 1 is the schematic diagram of packaging structure of the present invention;

In the figure: 1 is glass; 2 is the first chip; 3 is the spacer; 4 is the film structure; 5 is the second chip; 6 is the substrate; 7 is the plastic package structure; 8 is the metal conductor.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The present invention provides a photoelectric sensor packaging structure with pads. As shown in FIG. 1 , the packaging structure is used to simultaneously package the photoelectric sensor and the control processing chip, and the photoelectric sensor includes an optical heart rate sensor. The photoelectric sensor packaging structure includes a substrate 6, on which an adhesive film structure 4, a spacer 3, a first chip 2 and a glass 1 are sequentially arranged, wherein the adhesive film structure 4 is internally packaged with a second chip 5, and the adhesive film structure 4 The thickness is 110-135 μm; and the four sides of the film structure 4 are respectively flush with the four sides of the spacer 3; Plastic sealing structure 7; the four sides of the plastic sealing structure 7 are respectively flush with the four sides of the substrate 6, the upper surface of the plastic sealing structure 7 is flush with the upper surface of the glass 1, and the upper surface of the glass 1 is exposed.

Preferably, one side of the second chip 5 is bonded to the base, and the other side of the second chip 5 is electrically connected to the base through at least one metal conductor; the adhesive film structure 4 adopts FOD film, and the second chip 5 and the metal conductors are packaged in the adhesive film structure 4; as shown in FIG. 1 , neither the second chip 5 nor the metal conductors exceed the adhesive film structure 4.

Preferably, the side where the spacer 3 is connected to the film structure 4 is the film layer, and the film layer of the spacer 3 is connected to the film structure 4 downwards; The sides are flush.

Preferably, the first chip 2 has a negative electrode surface and a positive electrode surface, and the negative electrode surface of the first chip 2 is electrically connected to the other surface of the pad 3, and the surface of the pad 3 is connected to the other surface of the pad 3 through at least one metal conductor 8. The substrate 6 is electrically connected, so that the second chip 5 is electrically connected to the substrate 6 through the connection surface of the spacer 3 and the metal conductor 8 . Preferably, the other surface of the spacer 3 is plated with a metal layer, and the metal becomes a gold-plated layer, a silver-plated layer, an aluminum-plated layer or a copper-plated layer. Preferably, the negative electrode surface of the first chip 2 is coated with conductive silver paste, and the conductive silver paste is adhered to the metal layer.

Preferably, the positive side of the first chip 2 is set upwards, and the positive side of the first chip 2 has a sensing area and a non-sensing area; the sensing area is covered with glass 1; a number of pads are arranged on the non-sensing area , and is electrically connected to the substrate 6 through at least one metal conductor 8 . Preferably, the glass 1 is bonded to the sensing area on the positive electrode surface of the first chip 2 through an adhesive, and the adhesive is preferably a DAF adhesive film with a light transmittance of more than 90%.

The present invention also provides a packaging method for a photoelectric sensor, using the method to obtain the packaging structure of a photoelectric sensor with spacers as described above; the specific steps are:

Step S1, sticking one side of the second chip 5 on the substrate 6; setting the other side of the second chip 5 facing up, and electrically connecting the other side of the second chip 5 to the substrate 6 through at least one metal conductor .

In step S2 , a spacer 3 is placed above the second chip 5 , an adhesive film layer is provided on the downward side of the spacer 3 , and the adhesive film layer is opposite to the second chip 5 .

Step S3 , encapsulating the second chip 5 and its connected metal conductors with FOD adhesive film between the spacer 3 and the substrate 6 to obtain the adhesive film structure 4 . The adhesive film structure 4 completely encapsulates the second chip 5 and its connected metal conductors, and the second chip 5 and the metal conductors do not exceed the adhesive film structure 4 . The four sides of the film structure 4 are respectively flush with the four sides of the spacer 3 . The height of the film structure is between 110-135 μm.

Step S4, the upward side of the spacer 3 is electrically connected to the negative electrode surface of the first chip 2, and this surface of the spacer 3 is electrically connected to the substrate 6 through at least one metal conductor 8, so that the negative electrode of the second chip The metal conductor can be electrically connected to the substrate 6 through the surface.

Preferably, the upward side of the pad 3 is plated with a conductive metal layer, and the conductive metal layer is a gold-plated layer, a silver-plated layer, a copper-plated layer or an aluminum-plated layer; the conductive metal layer is electrically connected to the substrate 6 through a metal conductor. The negative surface of the second chip 2 is coated with conductive silver paste, through which the second chip 2 is connected to the conductive metal layer of the spacer 3 .

Preferably, the negative electrode surface of the second chip 2 completely covers the spacer 3 , and the area of the contact surface of the spacer 3 is larger than the area of the negative electrode surface of the second chip 2 .

In step S5, the positive side of the second chip 2 is set upward, the glass 1 is set on the positive side, and the positive side is also electrically connected to the substrate 6 through the metal conductor 8 . The positive surface of the second chip 2 has a sensing area and a non-sensing area, the glass 1 covers the sensing area, a plurality of pads are arranged on the non-sensing area, and the non-sensing area conducts electricity through at least one metal The body is electrically connected to the substrate 6 .

The preferred glass 1 is coated with a binder with high light transmittance, and then the side of the glass 1 coated with the binder is glued to the positive electrode surface; wherein the binder is a DAF adhesive film with a light transmittance of more than 90%.

Preferably, the area of the glass 1 is smaller than the area of the positive electrode surface of the second chip 2 .

In step S6, the structure obtained in step S5 is plastic-sealed with a molding compound; specifically, the film structure 4, spacer 3, first chip 2 and glass 1 are packaged and packaged on the substrate 6 with a molding compound to obtain a plastic-sealed structure 7 ; The plastic encapsulation structure 7 also encapsulates all metal conductors.

Preferably, the four sides of the plastic sealing structure 7 are respectively flush with the four sides of the substrate 6; the upper surface of the plastic sealing structure 7 is flush with the upper surface of the glass 1; the upper surface of the glass 1 is exposed.

In step S7, the photoelectric sensor packaging structure with pads of the present invention is obtained.

Claims (8)

1. A photoelectric sensor packaging structure with pads is characterized in that it comprises a substrate (6), the substrate (6) is provided with an adhesive film layer (4), and the adhesive film layer (4) is internally packaged with a second chip (5); Adhesive film layer (4) is provided with spacer (3), is provided with first chip (2) on spacer (3); The negative electrode face of first chip (2) and spacer (3) electric connection, the positive side of the first chip (2) faces up, and the positive side is covered with glass (1); One side of the second chip (5) is bonded to the substrate (6), and the other side is electrically connected to the substrate (6) through a metal conductor; One side of the spacer (3) is a conductive layer, and the other side is connected to the adhesive film layer (4); the conductive layer is arranged upward to contact the negative electrode surface of the first chip (2); the adhesive film layer (4) is arranged downward, and The adhesive film layer (4) completely wraps the second chip (5), and the thickness of the adhesive film layer (4) is greater than the thickness of the second chip (5); The positive surface of the first chip (2) is electrically connected to the substrate through a metal conductor; The side of the spacer (3) electrically connected to the first chip (2) is also electrically connected to the substrate (6) through a metal conductor; The substrate (6) is packaged with a plastic sealing structure (7), the plastic sealing structure (7) wraps the adhesive film layer (4), the spacer (3), the first chip (2) and the glass (1), and the plastic sealing structure ( 7) the top surface of the glass (1) is flush with the upper surface of the glass (1), and the upper surface of the glass (1) is exposed; The first chip (2) is an optical sensor chip; the second chip (5) is a control processing chip. 2. The photoelectric sensor packaging structure with pads according to claim 1, characterized in that, the positive electrode face of the first chip (2) has a sensing area and a non-sensing area; glass (1) covers the On the sensing area; the non-sensing area is electrically connected to the substrate (6) through several metal conductors. 3. The photoelectric sensor packaging structure with spacer according to claim 1, characterized in that, one side of the spacer (3) is plated with a metal layer, and the first chip (2) negative electrode surface and the metal layer electrical connection. 4. The photoelectric sensor with spacer according to claim 3, characterized in that, the negative electrode surface of the first chip (2) is arranged on the spacer (3) through conductive silver paste. 5 . The photoelectric sensor packaging structure with pads according to claim 3 , wherein the metal layer is electrically connected to the substrate through a metal conductor. 6. A packaging method for a photoelectric sensor, comprising the following steps: Step S1, bonding one side of the second chip (5) to the substrate (6), and electrically connecting the other side of the second chip (5) through a metal conductor; the second chip (5) is a control processing chip; Step S2, placing the spacer (3) above the second chip (5), the side of the spacer (3) opposite to the second chip (5) is provided with an adhesive film layer (4), and the adhesive film layer (4) It is an FOD adhesive film, and the adhesive film layer (4) completely wraps the second chip (5), and the thickness of the adhesive film layer (4) is greater than the thickness of the second chip (5); Step S3, the upward side of the spacer (3) is coated with a metal layer, the metal layer is electrically connected to the negative electrode surface of the first chip (2), and between the surface of the spacer (3) and the substrate (6) A metal conductor is connected between them, and the metal conductor makes the negative electrode surface of the first chip (2) electrically conductive with the substrate (6); the first chip (2) is an optical sensor chip; Step S4, the positive side of the first chip (2) faces up, the positive side includes a sensing area and a non-sensing area, and the glass (1) is bonded to the sensing area with an adhesive, and the non-sensing area is passed through the metal The conductor is electrically connected to the substrate; Step S5, wrapping the adhesive film layer (4), pad (3), first chip (2) and glass (1) on the substrate (6) with a plastic sealing compound to form a plastic sealing structure (7), and the upper surface of the plastic sealing structure The surface is flush with the upper surface of the glass (1), and the upper surface of the glass (1) is exposed; Step S7, obtaining the photoelectric sensor packaging structure with pads as claimed in claim 1 . 7. The packaging method of photoelectric sensor according to claim 6, characterized in that, in the step S2, the four sides of the adhesive film layer (4) are respectively flush with the four sides of the spacer (3). 8 . The packaging method for photoelectric sensors according to claim 6 , characterized in that, the four sides of the plastic packaging structure ( 7 ) are respectively flush with the four sides of the substrate ( 6 ).