JPH02218170A - Manufacture of semiconductor pressure sensor - Google Patents

Abstract

PURPOSE:To enable the sufficient thickness of a bonded layer for absorbing and relieving the thermal stress to be assured by a method wherein a semiconductor pressure sensor chip is bonded onto the diepad part of a leadframe wherein bumps are formed on specified positions. CONSTITUTION:The rear surface side of a semiconductor pressure sensor chip on whose front side the electrode parts 9 are formed is bonded onto the diepad part 2 of a leadframe on whose positions corresponding to the electrode parts 9 and the proper position for keeping the parallelism of the said sensor chip the bump 6a, 6b are formed and then the electrode parts 9 of the semiconductor sensor chip 7 and the lead parts 3 of the leadframe 1 are wire-bonded. Through these procedures, the sufficient thickness of a bonded layer 10 to absorb the thermal stress can be assured between the part of the diepad part 2 wherein the pump 6a, 6b are not formed and the semiconductor pressure sensor chip.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a semiconductor pressure sensor.

[Prior Art] Generally, in a semiconductor pressure sensor, a semiconductor pressure sensor chip having a diaphragm portion in which a gauge resistor is embedded has a silicon pedestal made of silicon single crystal for absorbing and relieving thermal stress applied to the diaphragm portion. It is attached to a lead frame etc. via the wire.

Manufacturing such a semiconductor pressure sensor involves bonding a semiconductor pressure sensor chip to a silicon pedestal, then bonding this silicon pedestal to a lead frame, etc., and then wire bonding the electrode part of the semiconductor pressure sensor chip and the lead frame. I try to do it.

[Problems to be Solved by the Invention] In this way, in the conventional manufacturing method, a silicon pedestal is provided to absorb and relieve thermal stress, which increases the cost and requires that Guibond be performed twice. First, there are drawbacks such as a complicated manufacturing process.

For this reason, it is conceivable to directly bond the semiconductor pressure sensor chip to the lead frame without providing a silicon pedestal, but in this case, a Guibond material made of silicone resin or the like is used to absorb and relieve thermal stress. If the thickness is increased, energy during subsequent wire bonding between the electrode portion of the semiconductor pressure sensor chip and the lead frame will be absorbed by the adhesive layer and will escape, resulting in problems such as wiring defects.

The present invention has been made in view of the above points, and allows a semiconductor pressure sensor chip to be directly bonded to a lead frame without providing a silicon pedestal. The aim is to prevent this from happening.

[Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, the back side of a semiconductor pressure sensor chip having an electrode part formed on the front side is located at a position corresponding to the electrode part and at a position corresponding to the electrode part. The electrode part of the semiconductor pressure sensor chip and the lead part of the lead frame are bonded with an adhesive to the die pad part of the lead frame, which has protrusions formed at appropriate positions to maintain the parallelism of the semiconductor pressure sensor chip. I'm trying to do wire bonding.

[Function] According to the above configuration, an adhesive layer having a thickness sufficient to absorb thermal stress can be ensured between the portion of the die pad portion where no protrusion is formed and the semiconductor pressure sensor chip, and the adhesive layer of the semiconductor pressure sensor chip of the die pad portion can be secured. Since a protrusion is formed at a position corresponding to the electrode part of the pressure sensor chip, the thickness of the adhesive layer in this part is thin, and this protrusion serves as a support for the semiconductor pressure sensor chip, and it is connected to the electrode part of the semiconductor pressure sensor chip. Energy is not absorbed during wire bonding of the lead portion of the lead frame, and wiring defects do not occur.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view of a lead frame l applied to an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG.
The figure is an enlarged sectional view taken along the section line A--A in FIG.

In FIG. 1, 2 is a chip mounting part where a semiconductor pressure sensor chip is mounted, so-called die pad part; 3
is the inner lead, 4 is the tie bar, and 5 is the outer lead.

This lead frame! In the die pad section 2 to which the semiconductor pressure sensor chip is attached, a protrusion 6a is formed at a position directly below the electrode section of the semiconductor pressure sensor chip, and when the semiconductor pressure sensor is attached, The protrusion 6b is formed at an appropriate position so that the balance of the length, that is, the parallelism can be maintained.

The protrusion heights of these protrusions 6a and 6b are selected to correspond to a layer thickness of the adhesive material sufficient to alleviate thermal stress. In this embodiment, these protrusions 6a, 6b are formed by press molding, as shown in FIG.

In the method for manufacturing a semiconductor pressure sensor of this embodiment, as shown in the plan view of FIG. 4 and the side view of FIG. It is bonded to the connecting electrode portion 9 on the semiconductor pressure sensor chip 7 by a thin metal wire 8 such as gold or the like with an adhesive material (Guibond material) 10 such as silicone resin or silicone resin with a layer thickness sufficient to alleviate thermal stress. Wire bonding is performed with the inner leads 3 of the lead frame l.

By forming the protrusions 6a and 6b on the lead frame l in this manner, a layer of the adhesive lO having a thickness sufficient to alleviate thermal stress is ensured in areas other than the protrusions 6a and 6b, and a layer of the adhesive lO is secured for wire bonding. The portion corresponding to the electrode portion 9 of the semiconductor pressure sensor chip 7 is provided with a protrusion 6a.
is formed, so energy during wire bonding is not absorbed.

After wire bonding, the sensor is completed by embedding it in a predetermined shape using a molded case and cutting the tie bar 4 to make the external lead 5 independent.

FIG. 6 shows a lead frame I applied to another embodiment of the present invention. 7 is its side view, and 8th is its 6th plan view.
It is a sectional view taken along the section line A-A in the figure, and parts corresponding to the above-described embodiments are given the same reference numerals. In the embodiment described above, the protrusion 6a.

6b is formed by press molding, but in this embodiment, the die pad portion 2° other than the portion where the protrusion is formed is etched.
ao, 6b,). The other configurations are the same as those in the above embodiment.

In the embodiments described above, the lead frame 1. Protrusions 6a, 6b, 6ao, 6bo were formed on the die pad portions 2, 2° of the io at positions corresponding to the electrode portions 9 of the semiconductor pressure sensor chip 7 and at appropriate positions to maintain parallelism. As another embodiment of the present invention, if parallelism can be maintained, the projections 6a,
6a0 may be formed.

In addition, in the case of a backside pressure receiving type semiconductor pressure sensor, a hole for conducting gas or liquid is formed in the die pad portion 2.2o, but the present invention can of course be applied to this case as well. It is.

[Effects of the Invention] As described above, according to the method of the present invention, a semiconductor pressure sensor chip is bonded to a die pad portion of a lead frame in which projections are formed at predetermined positions, and then the electrode portion and the lead frame are bonded together. Since the bonding layer is wire-bonded, it is possible to ensure a sufficient thickness of the adhesive layer to absorb and relieve thermal stress, and there is no possibility that energy will escape during wire-bonding and cause defects in the wiring. Therefore, the number of parts can be reduced compared to the conventional example in which a silicon pedestal is provided, and the manufacturing process can be simplified and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a lead frame applied to an embodiment of the present invention, FIG. 2 is a side view of FIG. 4 is a plan view showing the semiconductor pressure sensor chip attached to the lead frame of FIG. 1, FIG. 5 is a side view of FIG. 4, and FIG. 6 is applied to other embodiments of the present invention. 7 is a side view of the lead frame shown in FIG. 6, and FIG. 8 is a sectional view taken along the section line A--A of FIG. 6. 1.1. ...Lead frame, 2,2. ...Die pad part, 6a, 6b, 6a o, 6b o-...Protrusion, 7...Semiconductor pressure sensor chip, 9...Electrode part. Figure 3

Claims (1)

[Claims] (1) Protrusions are formed on the back side of the semiconductor pressure sensor chip, which has an electrode part formed on the front side, at a position corresponding to the electrode part and at an appropriate position to maintain the parallelism of the semiconductor pressure sensor chip. A method for manufacturing a semiconductor pressure sensor, characterized in that the electrode part of the semiconductor pressure sensor chip and the lead part of the lead frame are bonded to a die pad part of the lead frame with an adhesive, and wire bonded to the lead part of the lead frame.