JPH10274582A - Semiconductor pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor pressure sensor low in cost and strong against vibration. SOLUTION: A semiconductor pressure sensor chip 1 is jointed to a glass base seat 2, and an electrode of the semiconductor pressure sensor chip 1 is electrically connected to a circuit pattern 4, formed on a base substrate 3, through a bump 5 and die-bonded to the base substrate 3 by an adhesive 6. An atmosphere open hole 3a communicated with a diaphragm a is formed in the base substrate 3, and a taper 3b is formed on the semiconductor pressure sensor chip mounted face side of the atmosphere open hole 3a. The semiconductor pressure sensor chip 1 is enclosed in a recessed part 7a of a cover 7 having the recessed part 7a for enclosing the semiconductor pressure sensor chip 1, and a pressure lead-in hole 7b applying pressure into the recessed part 7a. The opening side in the recessed part 7a of the cover 7 is bonded onto the base substrate 3 by an adhesive 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor pressure sensor.

[0002]

2. Description of the Related Art FIG. 2 is a schematic sectional view showing a state in which a semiconductor pressure sensor according to a conventional example is mounted on a motherboard 3. As shown in FIG. In the figure, in the semiconductor pressure sensor, a semiconductor pressure sensor chip 1 is bonded to a glass pedestal 2 by an anodic bonding method or the like, and a concave portion 8a is provided substantially at the center of the bottom surface of the resin-molded package body 8, and the glass pedestal 2 is placed there. It is mounted with an adhesive 6 or the like. In the upper part of the package body 8, a pressure introducing hole 8b is formed which communicates with the semiconductor pressure sensor chip 1 through a through hole 2a formed substantially in the center of the glass pedestal 2.

The opening of the concave portion 8a formed on the bottom surface of the package body 8 is closed by a lid 9, whereby the inside of the concave portion 8a is sealed in the pressure reference chamber 1 with improved sealing.
It is 0.

The semiconductor pressure sensor chip 1 has a single crystal silicon substrate having a pressure receiving surface formed on one surface, a diaphragm 1a for converting pressure into stress, a strain gauge (not shown), and electrodes (not shown). In this method, a change in pressure is converted into a change in electric resistance by the piezoresistance effect and output.

The electrodes formed on the semiconductor pressure sensor chip 1 and the leads 11 integrally formed on the package body 8 are connected by bonding wires 12 such as Au wires, and the leads 11 are mounted with the semiconductor pressure sensors. After the diver cuts the lead frame serving as the lead 11 for connection with a circuit pattern (not shown) formed on the motherboard 3, the tip end of the portion protruding from the side surface of the package body 8 is substantially vertically downward. It is bent. The tip of the lead 11 is connected to the socket 1 mounted on the mother board 3.
Inserted into 3. Thus, the semiconductor pressure sensor is mounted on the motherboard 3.

Next, a different example of the conventional semiconductor pressure sensor will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a state in which a semiconductor pressure sensor according to a conventional example is mounted on a mother board 3. For convenience of description, the same components as those shown in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. The example shown in FIG. 3 differs from the example shown in FIG. 2 in the shape of the leads and the mounting method. In the example shown in FIG. 3, the leads 14 projecting from the side surface of the package body 8 are provided.
Is bent diagonally downward, and further, its tip is
It is bent so as to be substantially horizontal in the direction opposite to the package body 8 side. A circuit pattern 4 is formed on the mother board 3 corresponding to the shape of the lead 14, and is joined to the tip of the lead 14 by solder 15.

[0007]

However, in the above configuration, the semiconductor pressure sensor chip 1 is mounted on the package body 8 once, and then the pressure sensor is mounted on the mother board 3 on which the circuit pattern 4 is formed. , The assembly man-hours increased and the cost was increased.

Further, since the electrical connection between the electrodes of the semiconductor pressure sensor chip 1 and the leads 11 and 14 is made by the bonding wire 12, there is a problem that the bonding strength is weak and the vibration is weak.

[0009] The present invention has been made in view of the above points, and its object is to provide a low-cost,
An object of the present invention is to provide a semiconductor pressure sensor that is resistant to vibration.

[0010]

According to the first aspect of the present invention,
A semiconductor pressure sensor chip having a thin diaphragm and an electrode, a cover having a recess for accommodating the semiconductor pressure sensor chip, and a pressure introducing hole for applying pressure to the recess, and the semiconductor pressure sensor Mounting a chip and a cover, comprising a mother substrate having an air opening hole and a circuit pattern, wherein the circuit pattern is electrically connected to the electrode via a bump, and the air opening hole is ,
The semiconductor pressure sensor chip is arranged on the motherboard so as to communicate with the diaphragm, one surface of the diaphragm is set to the atmospheric pressure by the atmosphere opening hole, and the other surface is applied from the pressure introduction hole. The pressure is set to be introduced.

According to a second aspect of the present invention, in the semiconductor pressure sensor according to the first aspect, a taper is formed on a side of the mother substrate where the semiconductor pressure sensor chip is mounted in an atmosphere opening hole of the mother substrate. Things.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a semiconductor pressure sensor according to one embodiment of the present invention. In addition,
For convenience of explanation, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted. Semiconductor pressure sensor chip 1
Is bonded to the glass pedestal 2 by an anodic bonding method or the like, and the electrodes (not shown) of the semiconductor pressure sensor chip 1 are electrically connected to the circuit patterns 4 formed on the mother substrate 3 via the bumps 5. At the same time, a low stress adhesive 6 such as rubber, gel-like silicone resin or epoxy resin
Is die bonded. The mother board 3 has
An air opening hole 3a communicating with the diaphragm 1a is formed, and a taper 3b is formed on the semiconductor pressure sensor chip 1 mounting surface side of the air opening hole 3a.

The semiconductor pressure sensor chip 1 has a recess 7a for accommodating the semiconductor pressure sensor chip 1 and a recess 7a.
The cover 7 is housed in a concave portion 7a of a resin-molded cover 7 having a pressure introducing hole 7b for applying pressure therein, and the opening side of the concave portion 7a of the cover 7 is Glued.

Therefore, in the present embodiment, the step of mounting the semiconductor pressure sensor chip 1 on the package body as in the prior art can be omitted, and the number of steps can be reduced, and the cost can be reduced.

Further, since the electrodes of the semiconductor pressure sensor chip 1 are electrically connected to the circuit pattern 4 by the bumps 5, the reliability against vibration is improved.

In this embodiment, since the taper 3b is formed on the mounting side of the glass pedestal 2 in the air opening hole 3a of the motherboard 3, the air opening hole 3a is closed by the adhesive 6. Can be prevented.

In this embodiment, the glass pedestal 2 is joined to the semiconductor pressure sensor chip 1.
However, the present invention is not limited to this, and only the semiconductor pressure sensor chip 1 may be die-bonded to the mother substrate 3, whereby the semiconductor pressure sensor can be reduced in thickness.

In this embodiment, one side of the diaphragm 1a is set to the atmospheric pressure by the open-to-atmosphere hole 3a. However, the present invention is not limited to this. Is also good.

[0019]

According to the first aspect of the present invention, there is provided a semiconductor pressure sensor chip having a thin diaphragm and electrodes, a recess accommodating the semiconductor pressure sensor chip, and a pressure introducing hole for applying pressure to the recess. And a mother board having an atmosphere opening hole and a circuit pattern for mounting the semiconductor pressure sensor chip and the cover.
The circuit pattern is electrically connected to the electrodes via bumps, the semiconductor pressure sensor chip is arranged on the motherboard so that the air opening hole communicates with the diaphragm, and one surface of the diaphragm is open to the air opening hole. To atmospheric pressure by
Since the pressure applied from the pressure introduction hole is introduced to the other surface, the step of mounting the semiconductor pressure sensor chip on the package body as in the related art can be omitted,
The number of steps can be reduced to reduce costs. Since the electrodes of the semiconductor pressure sensor chip are electrically connected to the circuit pattern by bumps, the reliability against vibration is improved, and the cost is reduced. A semiconductor pressure sensor that is strong against the pressure can be provided.

According to a second aspect of the present invention, in the semiconductor pressure sensor according to the first aspect, a taper is formed on the side of the mother substrate where the semiconductor pressure sensor chip is mounted in the air opening hole, so that the semiconductor is made of an adhesive or the like. When the pressure sensor chip is mounted on the motherboard, it is possible to prevent the air opening hole from being closed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a semiconductor pressure sensor according to one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state where a semiconductor pressure sensor according to a conventional example is mounted on a mother board.

FIG. 3 is a schematic cross-sectional view showing a state in which a semiconductor pressure sensor according to a conventional example is mounted on a mother board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor pressure sensor chip 1a Diaphragm 2 Glass pedestal 2a Through-hole 3 Mother board 3a Air opening hole 3b Taper 4 Circuit pattern 5 Bump 6 Adhesive 7 Cover 7a Depression 7b Pressure introduction hole 8 Package body 8a Depression 8b Pressure introduction hole 9 Cover 10 Pressure reference chamber 11 Lead 12 Bonding wire 13 Socket 14 Lead 15 Solder

Claims (2)

[Claims] 1. A semiconductor pressure sensor chip having a thin-walled diaphragm and electrodes, a cover having a recess accommodating the semiconductor pressure sensor chip, and a pressure introducing hole for applying pressure to the recess. Mounting the semiconductor pressure sensor chip and the cover, comprising a mother substrate having an atmosphere opening hole and a circuit pattern, wherein the circuit pattern is electrically connected to the electrode via a bump, The semiconductor pressure sensor chip is arranged on the motherboard so that the atmosphere opening hole communicates with the diaphragm, and one surface of the diaphragm is set to atmospheric pressure by the atmosphere opening hole, and the other surface is A semiconductor pressure sensor wherein a pressure applied from the pressure introducing hole is introduced. 2. The semiconductor pressure sensor according to claim 1, wherein a taper is formed on a side of the mother substrate on which the semiconductor pressure sensor chip is mounted in an atmosphere opening hole.