CN108955998A - A kind of circuit board assembly structure of automobile differential pressure pickup - Google Patents

Abstract

The invention discloses a circuit board assembly structure of an automobile differential pressure sensor, comprising a base and a combined PCB circuit board, the base is provided with a positioning column, which is correspondingly located on the combined PCB circuit board above the base There is a positioning hole matched with the positioning column for positioning the base and the combined PCB circuit board; the base is also provided with a base through hole, which corresponds to the coaxial opening on the combined PCB circuit board above the opening of the base. There are circuit board via holes, and a wafer chip is attached to the combined PCB circuit board directly above the circuit board via hole, and the wafer chip is electrically connected to the combined PCB circuit board through gold wires; the other part of the combined PCB circuit board Electrically connect the conditioning chip and peripheral devices. On the basis of ensuring the reliability of the chip, the present invention can facilitate analysis and processing in case of failure, and at the same time can freely select and match the type of the chip on the circuit board to meet the needs of different use environments and improve its versatility.

Description

A circuit board assembly structure of an automotive differential pressure sensor

technical field

The invention relates to the technical field of differential pressure sensors for automobiles, in particular to a circuit board assembly structure used in differential pressure sensors.

Background technique

A differential pressure sensor is a sensor used to measure the difference between two pressures. It is usually used to measure the pressure difference between the front and rear ends of a device or component. The principle is that the original measured pressure acts directly on the diaphragm of the sensor. Make the diaphragm produce a micro-displacement proportional to the water pressure, so that the capacitance value of the sensor changes, and then use the electronic circuit to detect this change, and convert and output a standard measurement signal corresponding to the pressure.

The differential pressure sensor includes a casing, and a circuit board assembly for installing a wafer chip and a conditioning chip, etc. are arranged in the casing. The traditional automotive differential pressure sensor circuit board assembly uses a packaged differential pressure chip, that is, the wafer chip and conditioning chip circuit are potted in the package, and then pasted on the PCB circuit board. Although the circuit board assembly with this structure is easy to process, there are fewer types of differential pressure chips, and it is difficult to select a suitable chip for the automotive differential pressure sensor, and the packaged differential pressure sensor chip has not been treated for corrosion protection. , If there is a problem inside the differential pressure chip, the fault analysis cannot be carried out, and the analysis needs to be performed after removing the package, which not only increases the difficulty of operation, but also causes damage to the chip and affects the analysis results.

Contents of the invention

The technical problem to be solved in the present invention is to provide a circuit board assembly structure for the differential pressure sensor of an automobile. On the basis of ensuring the reliability of the chip, it is convenient to carry out analysis and processing when the sensor fails, and at the same time, the chip on the circuit board can be processed. The free selection and matching of models can meet the needs of different usage environments and improve its versatility.

In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

A circuit board assembly structure of an automobile differential pressure sensor, including a base and a combined PCB circuit board arranged up and down oppositely, the base is provided with a number of positioning columns, and the combined PCB circuit board located above the base is correspondingly A positioning hole is provided on the top to match with the positioning column for positioning the base and the combined PCB circuit board; a wafer chip is bonded to the top surface of one end of the combined PCB circuit board, and the wafer chip is connected to the combined PCB through a gold wire. The PCB circuit board is electrically connected, and the combined PCB circuit board located around the wafer chip is bonded with a barrier, and the groove between the barrier and the wafer chip on the combined PCB circuit board is filled with protective wafer chips and The gel of the gold wire; the other end of the combined PCB circuit board is electrically connected to the conditioning chip on the top surface.

The circuit board assembly structure of the above-mentioned automotive differential pressure sensor, the base is also provided with a base via hole, and the combined PCB circuit board above the corresponding base opening is coaxially provided with a circuit board via hole, the crystal The circular chip is arranged on the combined PCB circuit board directly above the through hole of the circuit board.

The circuit board assembly structure of the above-mentioned automotive differential pressure sensor, the combined PCB circuit board includes a ceramic PCB board and a glass fiber PCB board arranged on the same plane, and the adjacent respective side edges of the ceramic PCB board and the glass fiber PCB board A number of bonding pads are respectively provided, and the edge of the other side opposite to the bonding pads on the glass fiber PCB is provided with via pads electrically connected to external devices; between the bonding pads on the two PCB boards connected by aluminum wires.

The circuit board assembly structure of the above-mentioned automotive differential pressure sensor: the ceramic PCB board and the glass fiber PCB board are respectively provided with cylindrical positioning holes, and the gap between the ceramic PCB board and the glass fiber PCB board forms a strip shape positioning hole; correspondingly, the positioning post on the base also includes a cylindrical positioning post fitted with a cylindrical positioning hole and a strip-shaped positioning post fitted with a strip-shaped positioning hole; the strip-shaped positioning post is located on the aluminum line, and the top surface of the strip-shaped positioning column is flush with the top surface of the ceramic PCB board and the glass fiber PCB board.

In the circuit board assembly structure of the above-mentioned automotive differential pressure sensor, the wafer chip and the circuit board via holes are all arranged on the ceramic PCB board; the conditioning chip and peripheral devices are arranged on the glass fiber PCB board.

The circuit board assembly structure of the above-mentioned automotive differential pressure sensor is: the edge of the circuit board via hole on the bottom surface of the ceramic PCB board is sealed and connected with the edge of the base via hole on the top surface of the base.

In the circuit board assembly structure of the above-mentioned automotive differential pressure sensor, one end of the glass fiber PCB board provided with the through-hole pad protrudes out of the base.

Due to the adoption of the above technical solutions, the technological progress achieved by the present invention is as follows.

The invention strengthens the reliability of the differential pressure sensor circuit board assembly by performing special treatment on the wafer, and from the differential pressure wafer chip to the conditioning chip, all models can be freely selected for matching, meeting the needs of different use environments, and universal performance has been greatly improved; in addition, the circuit board assembly structure of the present invention removes the encapsulation structure and adopts a differential pressure wafer gold wire bonding process. When the sensor fails, it can be convenient, Fast and accurate fault analysis.

Description of drawings

Fig. 1 is the structural representation of invention;

Fig. 2 is a side view of the present invention;

Fig. 3 is an exploded view of the structure of the present invention;

Fig. 4 is a schematic structural diagram of the combined PCB circuit board of the present invention.

Among them: 1. Base, 2. Combined PCB circuit board, 21. Glass fiber PCB board, 22. Ceramic PCB board, 23. First bonding pad, 24. Aluminum wire, 25. Second bonding pad , 3, fence, 4, wafer chip, 5, positioning column, 6, conditioning chip, 7, gold wire, 8, gel, 9, circuit board via, 10, base via, 11, via Welding pad, 12, positioning hole.

Detailed ways

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

A circuit board assembly structure of an automotive differential pressure sensor, the structure of which is shown in Figures 1 to 3, including a base 1 and a combined PCB circuit board 2 arranged up and down oppositely, and the base 1 and the combined PCB circuit board 2 bonded together with sealant. The base is provided with a number of positioning columns 5, and correspondingly positioned on the combined PCB circuit board above the base is provided with positioning holes 12, and the positioning holes 12 are matched with the positioning columns for positioning the base 1 and the combined PCB circuit board 2.

The structure of the combined PCB circuit board 2 is shown in FIG. 4 , including a ceramic PCB board 22 and a glass fiber PCB board 21 arranged on the same plane. The combined PCB circuit board takes into account the advantages of the ceramic PCB board and the glass fiber PCB board, and the price is also lower than the ceramic PCB board, which makes the PCB circuit board design more flexible and reliable, and can meet the harsh environment and high performance of the car. requirements.

A side edge of the ceramic PCB board 22 is provided with several first bonding pads 23 for electrical connection with the glass fiber PCB board; the glass fiber PCB board 21 is adjacent to the first bonding pad 3 on the ceramic PCB board A number of second bonding pads 25 are arranged on the side edge, and the other side edge of the glass fiber PCB opposite to the second bonding pad 25 is provided with a via pad 11 electrically connected to an external device, and the glass fiber PCB One end of the plate 21 provided with the via pad 11 protrudes out of the base 1 for soldering connectors and the like. The first bonding pad 23 on the ceramic PCB 22 is correspondingly connected to the second bonding pad 25 on the glass fiber PCB 21 through an aluminum wire 24 .

In the present invention, the ceramic PCB board 22 and the glass fiber PCB board 21 are respectively provided with cylindrical positioning holes, and the gap between the ceramic PCB board 22 and the glass fiber PCB board 21 forms a strip-shaped positioning hole; The positioning post also includes a cylindrical positioning post fitted with a cylindrical positioning hole and a strip-shaped positioning post fitted with a strip-shaped positioning hole; the strip-shaped positioning post is located directly below the aluminum wire, and the strip-shaped positioning post The top surface of the ceramic PCB board 22 and the top surface of the glass fiber PCB board 21 are flush.

Wherein, the center of the ceramic PCB board 22 is provided with a corrosion-resistant wafer chip 4 , the wafer chip 4 is bonded to the ceramic PCB board 22 through a sealant, and the wafer chip 4 is electrically connected to the combined PCB circuit board through a gold wire 7 . The ceramic PCB board 22 located around the wafer chip 4 is bonded with a barrier 3, and the groove between the barrier and the wafer chip 4 on the ceramic PCB board 22 is filled with gel 8, and the gel formed by the gel The height of the adhesive layer is higher than that of the wafer chip and the gold wire, and is used to protect the wafer chip and the gold wire.

A circuit board via hole 9 is vertically provided on the ceramic PCB board 22 directly below the wafer chip 4, and the diameter of the circuit board via hole 9 is smaller than the minimum outer diameter of the wafer chip; corresponding to the base directly below the circuit board via hole 9 A base via hole 10 is provided on the top, and the base via hole 10 is arranged coaxially with the circuit board via hole 9, and the diameter of the base via hole 10 is larger than the maximum outer diameter of the wafer chip 4; the circuit on the bottom surface of the ceramic PCB board 22 The edge of the plate via hole 9 is sealed and connected with the edge of the base via hole 10 on the top surface of the base through a sealant to ensure that the gas can normally pass through the base via hole, the circuit board via hole, and go straight to the bottom of the wafer chip.

The setting of the circuit board via hole 9 and the base via hole 10 on the ceramic PCB board in the present invention can form reverse communication with the outside after the present invention is installed in the housing of the sensor, so as to facilitate the detection of reverse pressure difference; That is, when the present invention is applied to a differential pressure sensor, the external gas can communicate with the top surface of the wafer chip to detect the forward differential pressure, and can also communicate with the bottom surface of the wafer chip to detect the reverse differential pressure. detection.

The conditioning chip and peripheral devices are welded on the glass fiber PCB 21, as shown in FIG.

The present invention is applied in the production process of the differential pressure sensor of the automobile, and the wafer chip and the conditioning chip of the differential pressure sensor can be reasonably selected to meet the use requirements of different use environments; processing to ensure the reliability of the chip. Since the wafer chip and the conditioning chip are separately arranged on circuit boards of different materials, and the conditioning chip is connected to the circuit board by traditional welding technology, it is convenient to analyze and study the chip when a failure occurs.

Claims (7)

1. a kind of circuit board assembly structure of automobile differential pressure pickup, it is characterised in that: including the pedestal (1) being oppositely arranged up and down With combined type PCB circuit board (2), several positioning columns (5), the combined type being correspondingly situated above pedestal are provided on the pedestal The location hole being mutually equipped with positioning column for positioning pedestal (1) and combined type PCB circuit board (2) is offered in PCB circuit board (12)；It is bonded on one end top end face of the combined type PCB circuit board chip wafer (4), chip wafer (4) passes through gold thread (7) it is electrically connected with combined type PCB circuit board, is located in the combined type PCB circuit board on chip wafer (4) periphery and is bonded with jube (3), filled with protection chip wafer and gold in the groove in combined type PCB circuit board between jube and chip wafer (4) The gel (8) of line；Conditioning chip (6) are electrically connected on the other end top end face of combined type PCB circuit board.

2. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 1, it is characterised in that: the base It is also provided with pedestal via hole (10) on seat, coaxially offers circuit board in the combined type PCB circuit board above corresponding pedestal aperture Via hole (9), chip wafer (4) are arranged in the combined type PCB circuit board right above circuit board via (9).

3. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 1, it is characterised in that: described group Box-like PCB circuit board (2) includes the ceramic pcb board (22) and glass dimension pcb board (21) for being generally aligned in the same plane setting, ceramic PCB Plate (22) and glass tie up pcb board (21) adjacent respective side and tie up pcb board (21) along several bonding welding pads, glass is respectively arranged with The upper other side edge opposite with bonding welding pad is provided with the via pad (11) being electrically connected with external devices；Two pieces of pcb boards On bonding welding pad between by aluminum steel (24) connect.

4. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 3, it is characterised in that: the pottery Cylindrical location hole is respectively arranged on porcelain pcb board (22) and glass dimension pcb board (21), ceramic pcb board (22) and glass tie up PCB Gap between plate (21) forms strip location hole；Positioning column in corresponding pedestal also includes equipped with cylindrical location hole Cylindricality positioning column and the strip positioning column that is mutually equipped with strip location hole；The strip positioning column is being located at aluminum steel just Lower section, and the top end face of strip positioning column is concordant with ceramic pcb board (22) and the glass dimension top end face of pcb board (21).

5. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 3, it is characterised in that: the crystalline substance Round core piece (4) and circuit board via (9) are arranged on ceramic pcb board (22)；Conditioning chip and peripheral devices are arranged in glass On fiber pcb board (21).

6. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 3, it is characterised in that: the pottery Circuit board via (9) edge of porcelain pcb board (22) bottom face is connect with the pedestal via hole rim seal in Chuck top face.

7. a kind of circuit board assembly structure of automobile differential pressure pickup according to claim 3, it is characterised in that: the glass One end that via pad (11) are arranged in fiber pcb board (21) is stretched out outside pedestal.