JP2015014578A - Flow sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the bending deformation of a semiconductor chip due to the local breakage of an adhesive, even in a state where a diaphragm peripheral region is pressed by a metal mold.SOLUTION: In a lead frame 1, a groove part 18 is formed across the outside of one side surface 3c from an inner surface of a first semiconductor chip 3. If a pressing force is applied to a first adhesive 5 via the first semiconductor chip 3 by a partition protrusion 11a of an insert piece 11, the first adhesive 5 having a low Young's modulus and a high fluidity flows to the groove part 18 formed on the lead frame 1 and thereby, a local breakage does not occur in a peripheral region of a diaphragm 30. Thus, in the first semiconductor chip 3, a bending deformation does not occur, and strain and cracks do not occur.

Description

  The present invention relates to a flow rate sensor, and more particularly to a flow rate sensor including a semiconductor chip having a flow rate detection unit formed on a diaphragm.

An internal combustion engine such as an automobile includes an electronically controlled fuel injection device for appropriately operating the internal combustion engine by appropriately adjusting the amount of air and fuel flowing into the internal combustion engine. Electronically controlled fuel injectors
A flow sensor for measuring the flow rate of air flowing into the internal combustion engine is provided.
From the viewpoint of cost and performance, a flow sensor in which a diaphragm is formed on a semiconductor chip using a micromachining technique and a flow rate detection unit is provided on the diaphragm has been attracting attention.

  The flow rate detection unit includes a heating resistor and a resistance temperature detector, and measures the flow rate under the control of a control circuit unit provided on the same or different semiconductor chip. Such a flow rate sensor has a structure in which the flow rate detector is exposed and the periphery of the semiconductor chip is sealed with resin. When the sealing of the resin is performed by the potting method, a resin position shift or the like occurs, the mounting position of the flow sensor shifts for each flow sensor, and the performance of the flow sensor varies.

For this reason, the method of performing sealing with resin by the resin mold shown below is known.
The semiconductor chip on which the flow rate detection unit is formed is bonded to the lead frame with an adhesive. The upper mold that covers the main surface side of the semiconductor chip on which the flow rate detection unit is formed is formed with a partition projection for forming a space for exposing the flow rate detection unit. Resin is injected into the mold in a state in which the partitioning projection of the upper mold is in contact with the upper surface of the semiconductor chip around the flow rate detection section. Since the injected sealing resin is prevented from flowing into the space surrounding the flow rate detection unit by the partition projection, the flow rate sensor is exposed and a flow rate sensor whose periphery is sealed with resin is provided. It is formed (for example, see Patent Document 1).

International Publication WO2012 / 049934

  In the method described in Patent Document 1, in order to prevent the inflow of the resin to the periphery of the flow rate detection unit, the partition projection of the upper mold is applied around the flow rate detection unit formed on the main surface of the semiconductor chip. The semiconductor chip is pressed against the lead frame via an adhesive. Due to the pressing force by the mold, the part of the adhesive corresponding to the partitioning protrusion is locally crushed. At this time, the pressing force by the upper mold does not act on the adhesive region outside the region corresponding to the partition projection. Therefore, the adhesive is locally crushed and a downward pressing force acts on the semiconductor chip in the region corresponding to the crushed adhesive. For this reason, bending deformation occurs in the semiconductor chip starting from the vicinity of the thin diaphragm, and distortion and cracking are likely to occur. When the semiconductor chip having the flow rate detection unit is distorted or cracked, the flow rate detection becomes inaccurate or the flow rate detection becomes difficult.

(1) A flow sensor according to the present invention includes a support substrate, a main surface mounted on the support substrate, a main surface on which a flow rate detection unit is formed, and a back surface facing the main surface, and a recess is formed on the back surface. A semiconductor chip having a diaphragm formed on a recess in the surface, a resin that exposes the flow rate detection unit to cover the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip, and at least a diaphragm peripheral region and a diaphragm peripheral region on the back surface of the semiconductor chip And an adhesive that bonds the semiconductor chip and the support substrate, and at least the back surface of the semiconductor chip, the top surface of the support substrate, or between the back surface of the semiconductor chip and the top surface of the support substrate. And an adhesive flow structure in which the adhesive flows.
(2) Further, the flow sensor according to the present invention has a support substrate, a main surface mounted on the support substrate, on which a flow rate detection unit is formed, and a back surface facing the main surface, and a recess is formed on the back surface. A semiconductor chip in which a diaphragm is formed on a recess in the main surface; a resin that exposes the flow rate detection unit to cover the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip; and at least a diaphragm peripheral region and a diaphragm on the back surface of the semiconductor chip An adhesive that is provided between the support substrate corresponding to the peripheral region and adheres the semiconductor chip and the support substrate; the resin includes a first resin non-formation region that exposes the flow rate detection unit; And at least one second resin non-formation region exposing a part of the main surface of the semiconductor chip at a position spaced from the resin non-formation region.
(3) Further, the flow sensor according to the present invention has a support substrate, a main surface mounted on the support substrate, on which a flow rate detection unit is formed, and a back surface facing the main surface, and a recess is formed on the back surface. A semiconductor chip in which a diaphragm is formed on a recess in the main surface; a resin that exposes the flow rate detection unit to cover the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip; and at least a diaphragm peripheral region and a diaphragm on the back surface of the semiconductor chip An adhesive layer provided between the support substrate corresponding to the peripheral region and adhering the semiconductor chip and the support substrate; and the adhesive layer includes an adhesive and fine particles dispersed in the adhesive Including.
(4) Furthermore, the flow sensor according to the present invention has a support substrate, a main surface mounted on the support substrate, on which a flow rate detection unit is formed, and a back surface facing the main surface, and a recess is formed on the back surface. A semiconductor chip in which a diaphragm is formed on a recess in the main surface; a resin that exposes the flow rate detection unit to cover the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip; and at least a diaphragm peripheral region and a diaphragm on the back surface of the semiconductor chip The adhesive is provided between the supporting substrate corresponding to the peripheral region and adhesives the semiconductor chip and the supporting substrate, and the deformation that occurs in the semiconductor chip by crushing the adhesive region corresponding to the peripheral region of the diaphragm In order to prevent this, a crushing prevention mechanism for preventing local crushing of the adhesive is provided.

  According to the present invention, the flow sensor can prevent local collapse of the adhesive region corresponding to the diaphragm peripheral region. For this reason, it is possible to prevent deformation starting from the diaphragm of the semiconductor chip having the flow rate detecting portion formed on the main surface, and to prevent the semiconductor chip from being distorted or cracked.

1 is a top view of an embodiment of a flow sensor according to the present invention. II-II sectional view taken on the line of the flow sensor shown in FIG. The top view which shows the mounting structure of the state which was illustrated by FIG. 1 and in which the resin was removed in the flow sensor. FIG. 4 is a sectional view of the flow sensor shown in FIG. 3 taken along line IV-IV. Sectional drawing for demonstrating the method to accommodate the semiconductor chip which has the flow volume detection part shown in FIG. 4 in a metal mold | die, and to resin-mold. FIG. 6 is an enlarged view in the vicinity of the local crush prevention mechanism of the adhesive in FIG. 5. FIG. 7 is a diagram illustrating a state in which a pressing force by a mold is applied to the semiconductor chip in FIG. 6. (A), (b) is a figure which shows the modification of the local crushing prevention mechanism of the adhesive agent illustrated in FIG. The top view which shows Embodiment 2 of the flow sensor by this invention, and shows the mounting structure of the flow sensor in the state which removed resin. XX sectional drawing of the flow sensor shown in FIG. FIG. 11 is an essential part cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 10 in a mold and molding the resin. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. Sectional drawing of Embodiment 3 of the flow sensor by this invention. FIG. 14 is a plan view showing the mounting structure in a state where the resin is removed in the flow rate sensor shown in FIG. 13. FIG. 15 is a cross-sectional view of the flow sensor illustrated in FIG. 14 taken along line XV-XV. FIG. 16 is an essential part cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit illustrated in FIG. 15 in a mold and molding the resin. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. The top view of Embodiment 4 of the flow sensor by this invention. FIG. 19 is a cross-sectional view of the flow sensor illustrated in FIG. 18 taken along line XIX-XIX. FIG. 20 is a plan view showing a mounting structure in a state where resin is removed in the flow rate sensor shown in FIG. 19. XXI-XXI sectional view taken on the line of the flow sensor illustrated in FIG. FIG. 22 is a cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit illustrated in FIG. 21 in a mold and molding the resin. FIG. 23 is an enlarged view of the periphery of a mold insertion piece in FIG. 22. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. The top view which shows Embodiment 5 of the flow sensor by this invention, and shows the mounting structure of the flow sensor of the state which removed the resin. FIG. 26 is a sectional view of the flow sensor shown in FIG. 25 taken along line XXVI-XXVI. FIG. 27 is an essential part cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 26 in a mold and molding the resin. In FIG. 27, the figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip. The top view which shows Embodiment 6 of the flow sensor by this invention, and shows the mounting structure of the flow sensor of the state which removed resin. XXX-XXX sectional view taken on the line of the flow sensor illustrated in FIG. FIG. 31 is an essential part cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 30 in a mold and molding the resin. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. The top view of Embodiment 7 of the flow sensor by this invention. XXXIV-XXXIV sectional view taken on the line of the flow sensor illustrated in FIG. The top view which shows the mounting structure of the flow sensor of the state which removed the resin in the flow sensor illustrated in FIG. FIG. 36 is a sectional view of the flow sensor shown in FIG. 35 taken along the line XXXVI-XXXVI. FIG. 37 is a cross-sectional view of a principal part for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 36 in a mold and molding the resin. FIG. 38 is an enlarged view of the vicinity of the local crush prevention mechanism of the adhesive in FIG. 37. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. The top view which shows Embodiment 8 of the flow sensor by this invention, and shows the mounting structure of the flow sensor of the state which removed the resin. FIG. 41 is a sectional view of the flow sensor shown in FIG. 40 taken along the line XXXXI-XXXXI. FIG. 42 is an essential part cross-sectional view for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 41 in a mold and molding the resin. The figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip in FIG. The figure for demonstrating the subject at the time of producing the conventional flow sensor.

[Basic structure of the invention]
The basic structure of the flow sensor of the present invention is as follows.
The semiconductor chip has a flow rate detector on the main surface side. The flow rate detection unit is formed on a diaphragm formed on a thin wall on the main surface side from which the back surface side of the semiconductor chip is removed. The back surface of the semiconductor chip and the top surface of the support substrate are bonded with an adhesive. The main surface and the peripheral side surface of the semiconductor chip are sealed with a resin that exposes the flow rate detection unit. The flow sensor is provided with a local crushing prevention mechanism for the adhesive to prevent deformation of the semiconductor chip caused by crushing the area of the adhesive corresponding to the peripheral area of the diaphragm.
Various mechanisms can be employed as a mechanism for preventing local collapse of the adhesive.
In the following, various embodiments of a flow sensor having a mechanism for preventing local crushing of adhesive will be described with reference to the drawings.

--Embodiment 1--
[Overall structure]
First, with reference to FIGS. 1-8, Embodiment 1 of the flow sensor by this invention is demonstrated.
FIG. 1 is a top view of an embodiment of a flow sensor according to the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of the flow sensor illustrated in FIG. 3 is a plan view showing the mounting structure in a state where the resin is removed from the flow sensor shown in FIG. 1, and FIG. 4 is a sectional view taken along the line IV-IV of the flow sensor shown in FIG. is there.
In the following description, the X direction, the Y direction, and the Z direction are as illustrated.
The flow sensor 100 includes a lead frame 1, a first semiconductor chip 3 mounted on the lead frame 1, a second semiconductor chip 4, and a first adhesive 5 that bonds the first semiconductor chip 3 to the lead frame 1. A second adhesive 6 for bonding the second semiconductor chip 4 to the lead frame 1, and a resin 14 for exposing the peripheral portion of the lead frame 1 to seal the first semiconductor chip 3 and the second semiconductor chip 4. ing.

The lead frame 1 is formed of, for example, a metal member such as copper. The lead frame 1 is provided in a temporary connection portion 1c formed in a rectangular frame shape and the temporary connection portion 1c, and the first semiconductor chip 3 is mounted thereon. It has a second die 1b on which the first die 1a and the second semiconductor chip 4 are mounted.
The first semiconductor chip 3 has a flow rate detection unit 2 on the main surface 3a side. The flow rate detection unit 2 includes a heating resistor (not shown) and a temperature measuring resistor constituting a temperature sensor bridge. A heater control bridge (not shown) is formed on the main surface 3 a of the first semiconductor chip 3 around the flow rate detection unit 2. The back surface 3b side of the flow rate detection unit 2 of the first semiconductor chip 3 is removed by anisotropic etching or the like to form a recess 31, and a thin diaphragm 30 is formed on the main surface 3a side. A heating resistor (not shown) or a heating resistor and a resistance temperature detector are arranged on the diaphragm 30, and a temperature sensor bridge is arranged around the diaphragm 30.

The second semiconductor chip 4 is formed with a control circuit unit for controlling the flow rate detection unit and measuring the flow rate. The first semiconductor chip 3 and the second semiconductor chip 4 are connected by wire bonding using a wire 7a such as gold. The second semiconductor chip 4 and the lead frame 1 are connected by wire bonding using a wire 7b such as gold. One ends of the wires 7 a and 7 b are connected to the first semiconductor chip 3 and the second semiconductor chip 4, and the other ends of the wires 7 a and 7 b are connected to the lead frame 1. When the temporary connecting portion 1c of the lead frame 1 is cut, the connecting portion to which the other ends of the wires 7a and 7b are connected is separated from the lead frame 1, and an external connection terminal is formed.
Details of the flow rate detection unit 2 and the control circuit unit are disclosed in International Publication WO2012 / 049934.

The entire back surface of the second semiconductor chip 4 is bonded to the upper surface of the second die 1 b of the lead frame 1 with a second adhesive 6.
The entire back surface 3 b of the first semiconductor chip 3 is bonded to the upper surface of the first die 1 a of the lead frame 1 by the first adhesive 5. As shown in FIG. 4, the first die 1a of the lead frame 1 has a groove 18 formed on the upper surface side over the entire length in the width (Y) direction. The groove 18 is formed from the inside of the first semiconductor chip 3 to the outside of the one side surface 3 c of the first semiconductor chip 3. The first adhesive 5 is disposed above the groove 18 inside the one side surface 3 c of the first semiconductor chip 3.
As the first adhesive 5 and the second adhesive 6, for example, a thermosetting resin such as an epoxy resin or a polyurethane resin, or a thermoplastic resin such as a polyimide or an acrylic resin can be used.

  The first semiconductor chip 3, the second semiconductor chip 4, the wires 7 a and 7 b, and the lead frame 1 are sealed with a resin 14 with the peripheral edge of the lead frame 1 exposed. The resin 14 has an opening 14 a that exposes the flow rate detection unit 2 formed on the main surface 3 a side of the first semiconductor chip 3. As the resin 14, for example, a thermosetting resin such as an epoxy resin or a phenol resin, or a thermoplastic resin such as polycarbonate or polyethylene terephthalate can be used. Further, fibers such as glass and mica, fine particles and the like may be dispersed in the resin.

[Resin sealing]
In the flow rate sensor 100 shown as the above-described embodiment, the groove portion 18 formed in the lead frame 1 forms an adhesive flow structure in which the first adhesive 5 flows. It functions as a typical collapse prevention mechanism 20A.
This will be described below.

FIG. 5 is a cross-sectional view for explaining a method of resin molding by housing the semiconductor chip having the flow rate detection unit shown in FIG. 4 in a mold. 6 is an enlarged view in the vicinity of the local crush prevention mechanism of the adhesive in FIG. 5, and FIG. 7 is a diagram showing a state in which the pressing force by the mold acts on the semiconductor chip in FIG. .
In order to seal the first semiconductor chip 3, the second semiconductor chip 4, the wires 7 a and 7 b and the lead frame 1 with the resin 14, the flow sensor 100 before resin sealing shown in FIG. The stop flow rate sensor 100 a ”is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9. The upper die 8 is provided with an insertion piece 11 slidable in the vertical (Z) direction. On the lower surface of the insert piece 11, an annular partition protrusion 11 a that abuts the periphery of the diaphragm 30 is formed. A space S is formed on the inner surface side of the lower end of the partitioning protrusion 11a.
An elastic film 12 is provided on the cavity 13 of the upper mold 8 and the lower surface of the insert piece 11. The elastic film 12 prevents the molten resin from leaking from the gap between the upper mold 8 and the lower mold 9 when the upper mold 8 and the lower mold 9 are clamped and molten resin is injected. . As the elastic film 12, for example, a polymer such as Teflon (registered trademark) or a fluororesin can be used.

  A height adjusting mechanism 40 is provided on the upper part of the insertion piece 11. The height adjusting mechanism 40 includes a support plate 41 fixed on the upper mold 8, a pressing member 42 arranged on the insert piece 11, and a height adjusting bolt 43 fixed to the pressing member 42. The The thread portion of the height adjustment bolt 43 is screwed into a female screw provided on the support plate 41, and the pressing member 42 moves up and down by rotating the height adjustment bolt 43. As a result, the pressing force of the insert piece 11 in contact with the first semiconductor chip 3 is adjusted. The pressing force is adjusted so that the molten resin injected into the cavity 13 does not bleed into the space S and the first semiconductor chip 3 does not deform from the periphery of the diaphragm 30 as a starting point.

  The height adjusting mechanism 40 adjusts the insert piece 11 to abut against the main surface 3a of the first semiconductor chip 3 with an appropriate pressing force, and injects a molten resin, whereby the unsealed flow sensor 100a is filled with the resin 14. Is sealed. Thereafter, the temporary connection portion 1c of the lead frame 1 is cut to manufacture the flow sensor 100.

As illustrated in FIG. 6, in a state where the main surface 3 a of the first semiconductor chip 3 is pressed by the partition protrusion 11 a of the insert piece 11, the region 5 a of the first adhesive 5 corresponding to the partition protrusion 11 a. In addition, a pressing force larger than that of the other region 5b acts.
FIG. 44 shows a cross-sectional view of a conventional flow sensor 200.
When a large pressing force acts on the region 5a of the first adhesive 5 via the first semiconductor chip 3 due to the pressing force from the partition projection 11a, the first adhesive 5 has a low elastic modulus and high fluidity. The first adhesive 5 in this region 5a is crushed. However, the pressing force acting on the region 5b of the first adhesive 5 at a position away from the partition projection 11a is small. For this reason, the position of the first semiconductor chip 3 corresponding to the region 5a tends to be lowered. Since the diaphragm 30 is thin and has low strength, the first semiconductor chip 3 starts from the periphery of the diaphragm 30 and the vicinity of the diaphragm 30 is lowered and the one side surface 3c is raised as shown in FIG. Bends and deforms. When the semiconductor chip is deformed, the first semiconductor chip 3 is distorted or cracked, so that the flow rate detection becomes inaccurate or the flow rate detection becomes difficult.

[Crush prevention mechanism]
On the other hand, in the flow sensor 100 of the above-described embodiment, the groove portion 18 is formed in the lead frame 1.
As illustrated in FIG. 7, when the pressing force by the partition protrusion 11 a acts on the first adhesive 5 via the first semiconductor chip 3, the first adhesive 5 having a low elastic modulus and high fluidity is It flows into the groove 18 formed in the lead frame 1. For this reason, although the thickness of the first adhesive 5 is reduced as a whole, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.

  As described above, in the above embodiment, in the flow sensor 100 in which the flow rate detection unit 2 adheres the first semiconductor chip 3 formed on the diaphragm 30 to the lead frame 1 with the first adhesive 5, A groove portion 18 through which the first adhesive 5 flows is formed. For this reason, even when a large pressing force acts around the diaphragm 30 of the first semiconductor chip 3, the first adhesive 5 flows into the groove 18, and the first adhesive 5 is locally crushed. It is possible to prevent the first semiconductor chip 3 from being deformed starting from the periphery of the diaphragm 30 and causing distortion or cracking.

  The groove portion 18 of the lead frame 1 is formed by pressing or cutting. The volume of the groove portion 18 does not need to be greater than or equal to the volume of the first adhesive 5, and it is sufficient to secure a region where a part of the first adhesive 5 flows and escapes from the adhesion region with the first semiconductor chip 3. The shape of the groove 18 illustrated as an embodiment in FIGS. 6 and 7 is formed in a substantially rectangular shape with a right angle at the corner where the bottom surface and the peripheral side surface intersect. However, the shape of the groove portion 18 is not limited to this shape, and can be appropriately modified and applied.

[Modification]
FIG. 8A and FIG. 8B are diagrams showing a modification of the local crushing prevention mechanism of the adhesive shown in FIG.
The groove portion 18 illustrated in FIG. 8A has an inclined surface in which the peripheral side surface of the bottom surface is gradually inclined in the direction of expansion from the bottom surface toward the opening side. With this shape, the flow of the first adhesive 5 into the groove 18 is promoted.
The groove portion 18 illustrated in FIG. 8B is chamfered at the corner portion where the bottom surface and the peripheral side surface intersect the groove portion 18 illustrated in FIG. 8A and the opening side end portion of the groove portion 18. Yes. By providing chamfering, the flow of the first adhesive 5 into the groove portion 18 can be further promoted.

  The structure and shape of the groove 18 formed in the lead frame 1 are not limited to the above-described embodiment and modification. The shape of the peripheral side surface may be a stepped shape, or the bottom surface may not be horizontal, but may be an inclined shape that gradually decreases toward the outside.

In the above-described embodiment, the groove portion 18 formed in the lead frame 1 is exemplified as a structure formed from the inner side of the first semiconductor chip 3 to the outer side of the one side surface 3c of the first semiconductor chip 3.
However, the groove 18 may be formed on the other side surface of the first semiconductor chip 3 or may be formed in an annular shape surrounding the first semiconductor chip 3 along the peripheral side surface of the first semiconductor chip 3. Further, the groove 18 may be formed inside the circumferential surface of the first semiconductor chip 3 so as to be surrounded by the first adhesive 5.

  In the embodiment described above, the groove portion 18 formed in the lead frame 1 is formed by removing the upper surface side of the lead frame 1, in other words, in the portion where the groove portion 18 is formed, the lead frame 1 is It was exemplified as a thin structure. However, the groove 18 may be bent into a concave shape while maintaining the plate thickness by pressing or the like. That is, the entire lead frame 1 including the portion where the groove 18 is formed may have the same thickness.

  In the above embodiment, the control circuit unit is exemplified as the flow sensor 100 formed in the second semiconductor chip 4. However, the control circuit unit is formed in the first semiconductor chip 3 and the first semiconductor is formed on the lead frame 1. A flow sensor 100 on which only the chip 3 is mounted may be used.

--Embodiment 2-
With reference to FIGS. 9-12, the flow sensor of Embodiment 2 of this invention is demonstrated.
FIG. 9 is a plan view showing a flow sensor mounting structure in which the flow sensor according to the second embodiment of the present invention is removed, from which resin is removed, and FIG. 10 is a cross-sectional view of the flow sensor shown in FIG. FIG. FIG. 11 is a cross-sectional view of a main part for explaining a method of housing a semiconductor chip having the flow rate detection unit shown in FIG. 10 in a mold and molding the resin. FIG. It is a figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip.
The second embodiment is characterized in that a concave portion 33 is formed in the first semiconductor chip 3 as a local crush prevention mechanism 20B of the first adhesive 5. Hereinafter, this characteristic structure will be mainly described. In the structure similar to that of Embodiment 1, the same reference numerals are assigned to the corresponding members, and the description thereof is omitted.

  As shown in FIG. 10, the flow rate sensor 100 of the second embodiment is provided with a second recess 33 on the back surface 3 b side of the first semiconductor chip 3. The second recess 33 is formed by anisotropic etching of a semiconductor element such as silicon. The second recess 33 is formed shallower than the first recess 31 between the first recess 31 provided below the diaphragm 30 and one side surface 3 c of the first semiconductor chip 3. Therefore, the strength of the first semiconductor chip 3 in the portion where the second recess 33 is formed is greater than the strength of the portion where the diaphragm 30 is formed.

  As shown in FIG. 11, the unsealed flow rate sensor 100 a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insertion piece 11 is adjusted. At this time, as shown in FIG. 12, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning projection 11 a of the insert piece 11. For this reason, the pressing force larger than the other area | region 5b acts on the area | region 5a of the 1st adhesive agent 5 corresponding to the protrusion part 11a for a partition. However, since the second recess 33 is formed on the back surface 3 b side of the first semiconductor chip 3, the first adhesive 5 having a low elastic modulus and high fluidity flows into the second recess 33.

Therefore, although the thickness of the first adhesive 5 is reduced as a whole, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.
Thus, in the second embodiment, the second recess 33 formed in the first semiconductor chip 3 constitutes an adhesive flow structure in which the first adhesive 5 flows, and thereby the first adhesive 5 serves as a local collapse prevention mechanism 20B.
Therefore, the second embodiment also has the same effect as the first embodiment.

  In the second embodiment, the second recess 33 of the first semiconductor chip 3 is formed inside the first semiconductor chip 3 between the diaphragm 30 on the back surface 3b side of the first semiconductor chip 3 and the one side surface 3c. Exemplified as a structure. However, the second recess 33 of the first semiconductor chip 3 may be formed from the inner side of the first semiconductor chip 3 to the outer side of the one side surface 3c. The second recess 33 of the first semiconductor chip 3 is formed on a plurality of side surfaces of the first semiconductor chip 3 or is formed in an annular shape surrounding the first semiconductor chip 3 along the peripheral side surface. Or you may. Furthermore, the opening periphery of the second recess 33 can be chamfered, or the planar shape can be an ellipse instead of a rectangle, or can be applied with appropriate deformation.

--Embodiment 3--
With reference to FIGS. 13-17, the flow sensor of Embodiment 3 of this invention is demonstrated.
FIG. 13 is a cross-sectional view of a third embodiment of the flow sensor according to the present invention, FIG. 14 is a plan view showing the mounting structure in a state where the resin is removed from the flow sensor shown in FIG. FIG. 15 is a cross-sectional view of the flow sensor illustrated in FIG. 14 taken along line XV-XV. FIG. 16 is a cross-sectional view of a main part for explaining a method of housing the semiconductor chip having the flow rate detection unit shown in FIG. 15 in a mold and molding the resin. FIG. It is a figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip.
In the third embodiment, the first adhesive 5 provided between the back surface 3b of the first semiconductor chip 3 and the upper surface of the lead frame 1 is used as the first crushing prevention mechanism 20C for the first adhesive 5. It is characterized in that a so-called gap 22 is formed in which the adhesive 5 is not formed. The gap 22 of the first adhesive 5 is provided outside the region corresponding to the partitioning projection 11 a of the insert piece 11. Hereinafter, this characteristic structure will be mainly described. In the structure similar to that of Embodiment 1, the same reference numerals are assigned to the corresponding members, and the description thereof is omitted.

  As illustrated in FIG. 17 and the like, the first adhesive 5 is formed only around the diaphragm 30 between the back surface 3b of the first semiconductor chip 3 and the top surface of the lead frame 1, and the first semiconductor In the vicinity of one side surface 3 c of the chip 3, there is a structure having a gap portion 22 where the first adhesive 5 is not formed. Hereinafter, in this specification, the area | region inside the outer peripheral side surface of the protrusion 11a for partition of the insertion piece 11 is defined as a diaphragm peripheral area.

  As shown in FIG. 16, the unsealed flow rate sensor 100 a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insertion piece 11 is adjusted. At this time, as shown in FIG. 17, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning protrusion 11 a of the insert piece 11. For this reason, the pressing force larger than the other area | region 5b acts on the area | region 5a of the 1st adhesive agent 5 corresponding to the protrusion part 11a for a partition. However, since the gap 22 where the first adhesive 5 is not formed is formed outside the partition projection 11a of the insert piece 11 on the back surface 3b side of the first semiconductor chip 3, the elastic modulus is small. The first adhesive 5 having high fluidity flows into the gap 22.

Therefore, although the thickness of the first adhesive 5 is reduced as a whole, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.
As described above, in the third embodiment, the first adhesive 5 is formed by providing the gap 22 outside the peripheral area of the diaphragm in the first adhesive 5 that bonds the first semiconductor chip 3 and the lead frame 1. A flowing adhesive flow structure is configured, thereby fulfilling a function as a local collapse prevention mechanism 20C of the first adhesive 5.
Therefore, the third embodiment also has the same effect as the first embodiment.

  In the third embodiment, the gap portion 22 of the first adhesive 5 is exemplified as a structure formed on the one side surface 3c side of the first semiconductor chip 3 outside the partition projection 11a. However, the gap 22 of the first adhesive 5 may be formed corresponding to a plurality of side surfaces of the first semiconductor chip 3 or may be formed in an annular shape surrounding the peripheral side surface of the first semiconductor chip 3.

--Embodiment 4--
With reference to FIGS. 18-24, the flow sensor of Embodiment 4 of this invention is demonstrated.
18 is a top view of Embodiment 4 of the flow sensor according to the present invention, and FIG. 19 is a cross-sectional view of the flow sensor shown in FIG. 18 taken along line XIX-XIX. 20 is a plan view showing a mounting structure in which the resin is removed from the flow sensor shown in FIG. 19, and FIG. 21 is a cross-sectional view taken along the line XXI-XXI of the flow sensor shown in FIG. FIG. 22 is a cross-sectional view for explaining a method of housing the semiconductor chip having the flow rate detection unit shown in FIG. 21 in a mold and molding the resin, and FIG. 23 is a mold in FIG. FIG. 24 is a diagram showing a state in which the pressing force by the mold acts on the semiconductor chip in FIG.
In the fourth embodiment, as the local crushing prevention mechanism 20D of the first adhesive 5, a part of the first semiconductor chip 3 is formed on the first semiconductor chip 3 separately from the opening 14a exposing the flow rate detection unit 2. The second opening 14b is exposed. As will be described later, the second opening 14b is formed by a pressing protrusion 11b that presses the first semiconductor chip 3 (see FIGS. 20 and 23). The second opening 14b formed in the resin 14 shows a trace of the resin 14 being formed in a state where the first semiconductor chip 3 is pressed around the first opening 14a and in the second opening 14b. Show. If the first semiconductor chip 3 is pressed around the first opening 14a and the second opening 14b, a uniform pressing force acts on the first adhesive 5 as a whole.

  As described above, in the fourth embodiment, as the local crush prevention mechanism 20D of the first adhesive 5, the second opening portion 14b showing a trace of the pressing force acting uniformly on the entire first semiconductor chip 3 is shown. It is characterized in that is formed. Hereinafter, this characteristic structure will be mainly described. In the structure similar to that of Embodiment 1, the same reference numerals are assigned to the corresponding members, and the description thereof is omitted.

As illustrated in FIG. 18, the resin 14 of the flow sensor 100 is provided with a first opening 14 a that exposes the flow rate detection unit 2 and a distance from the first opening 14 a, and the first semiconductor chip. A second opening 14b is formed to expose the other part of 3.
As shown in FIG. 20, the first semiconductor chip 3 is connected to the lead frame 1 at a substantially central portion in the length (X) direction of the first semiconductor chip 3 by a wire 7 c. The second semiconductor chip 4 is connected to the lead frame 1 by wires 7b and 7d. The portion of the lead frame 1 to which the wires 7b, 7c, and 7d are connected is externally separated from the lead frame 1 by sealing the unsealed flow rate sensor 100a with the resin 14 and then cutting the temporary connection portion 1c. This is a connection terminal.

As shown in FIG. 22, the unsealed flow rate sensor 100 a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9. In the insertion piece 11A, a partition projection 11a and a pressing projection 11b are formed to form a first opening 14a and a second opening 14b of the resin 14. As shown by a two-dot chain line in FIG. 20, the partitioning projection 11 a is formed in a rectangular frame shape surrounding the diaphragm 30, and the pressing projection 11 b is formed in a rectangular shape that is long in the width (Y) direction. Has been.
The partitioning projection 11a and the pressing projection 11b are brought into contact with the main surface 3a of the first semiconductor chip 3, and the height of the insertion piece 11A is adjusted in this state. As illustrated in FIG. 23, a space S is formed around the diaphragm 30 by the partitioning protrusion 11 a of the insert piece 11 </ b> A. A gap between the space S and the pressing protrusion 11b is a gap K between the partitioning protrusion 11a and the pressing protrusion 11b illustrated in FIG. Thus, the resin is filled during molding.
The height of the insertion piece 11A in the gap K (the length in the Z direction) is set such that the end of the wire 7c connected to the first semiconductor chip 3 is accommodated.

  In the step of adjusting the height of the insert piece 11A, the peripheral region of the diaphragm 30 on the main surface 3a side of the first semiconductor chip 3 is pressed by the partitioning projection 11a of the insert piece 11A and the insert piece 11A is pressed. The edge on the side surface 3c side on the main surface 3a side of the first semiconductor chip 3 is pressed by the protruding portion 11b. In the first to third embodiments, only the peripheral region of the diaphragm 30 on the main surface 3a side of the first semiconductor chip 3 is pressed by the partition projection 11a of the insert piece 11A. For this reason, the pressing force larger than the other area | region 5b acted on the area | region 5a corresponding to the diaphragm 30 periphery area | region in the 1st adhesive agent 5. FIG.

  On the other hand, in the case of Embodiment 4, as shown in FIG. 24, the first adhesive 5 includes a region corresponding to the peripheral region of the diaphragm 30 and a first semiconductor chip corresponding to the pressing protrusion 11b. 3 is pressed against the edge on the one side surface 3c side. For this reason, the first adhesive 5 is uniformly divided into a region 5a corresponding to the partitioning projection 11a and the pressing projection 11b, and a region 5b not corresponding to the partitioning projection 11a and the pressing projection 11b. A pressing force acts. Therefore, local crushing does not occur around the diaphragm 30 in the first adhesive 5. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.

  When the height of the insertion piece 11A is adjusted, the partition projection 11a and the pressing projection 11b of the insertion piece 11A are in contact with the main surface 3a of the first semiconductor chip 3 with an appropriate pressing force. By injecting the resin, the unsealed flow rate sensor 100 a is sealed with the resin 14. By injecting the molten resin, the outer periphery of the first semiconductor chip 3 and the gap K are filled with the molten resin. Thereafter, the temporary connection portion 1c of the lead frame 1 is cut to manufacture the flow sensor 100 shown in FIGS.

The manufacturing method of Embodiment 4 is summarized as follows.
(1) An unsealed flow sensor 100a is prepared.
The unsealed flow rate sensor 100 a may have a structure in which the entire back surface 3 b of the first semiconductor chip 3 is bonded to the lead frame 1 with the first adhesive 5.
(2) On the main surface 3a of the first semiconductor chip 3, the periphery of the diaphragm 30 and the position outside the diaphragm peripheral region, for example, the edge of the one side surface 3c are pressed, and the first semiconductor chip 3 and the first adhesive are bonded. Press against the lead frame 1 through the agent 5.
When the edge of one side surface 3c of the first semiconductor chip 3 is pressed, it is desirable that there is no wire 7c in this region. For this reason, the electrode of the first semiconductor chip 3 to which the wire 7c is connected may be formed inside the edge of the one side surface 3c.

(3) Thereafter, the unsealed flow sensor 100a is sealed with the sealing resin 14.
For the resin sealing, a method by molding is suitable. In this case, the resin 14 is preferably formed so as to cover the wire 7c.
By the above method, the flow rate sensor 100 sealed with the resin 14 in which the first opening 14a exposing the diaphragm 30 and the second opening 14b exposing the other region of the first semiconductor chip 3 are formed. Is formed.

In the fourth embodiment, the first opening (resin non-formation region) 14a that exposes the diaphragm 30 and the other region of the first semiconductor chip 3 are exposed to the resin 14 that seals the unsealed flow sensor 100a. A second opening (resin non-formation region) 14b is provided. The second opening 14b shows a trace of the pressing force being applied uniformly to the entire first semiconductor chip 3. As described above, since the pressing force acts uniformly on the entire first semiconductor chip 3, the local crushing prevention mechanism 20 </ b> D of the first adhesive 5 is provided.
Therefore, the fourth embodiment also has the same effect as the first embodiment.

--Embodiment 5--
A flow sensor according to a fifth embodiment of the present invention will be described with reference to FIGS.
FIG. 25 is a plan view showing a flow sensor mounting structure in a state in which a resin is removed, showing Embodiment 5 of the flow sensor according to the present invention, and FIG. 26 is an XXVI-XXVI of the flow sensor shown in FIG. It is line sectional drawing. FIG. 27 is a cross-sectional view of a main part for explaining a method of housing the semiconductor chip having the flow rate detection unit shown in FIG. 26 in a mold and molding the resin. FIG. It is a figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip.
In the fifth embodiment, as the local crushing prevention mechanism 20E of the first adhesive 5, the first adhesive layer 5A in which the fine particles 26 are dispersed in the first adhesive 5 is used as the back surface 3b of the first semiconductor chip 3 and the lead. It is characterized in that the structure is interposed between the upper surface of the frame 1. Hereinafter, this characteristic structure will be mainly described. In the structure similar to that of Embodiment 1, the same reference numerals are assigned to the corresponding members, and the description thereof is omitted.

  As shown in FIG. 26, in the flow sensor 100 of the fifth embodiment, an adhesive layer 5 </ b> A is interposed between the back surface 3 b of the first semiconductor chip 3 and the top surface of the lead frame 1. The adhesive layer 5 </ b> A is composed of the first adhesive 5 and the fine particles 26 dispersed in the first adhesive 5. The second semiconductor chip 4 is bonded to the lead frame 1 with a second adhesive 6.

As the first adhesive 5, for example, a thermosetting resin such as an epoxy resin or a polyurethane resin, or a thermoplastic resin such as polyimide or an acrylic resin can be used.
The fine particles 26 have a substantially spherical shape, preferably have a diameter of 2 to 30 μm and a content of about 10 to 60 wt%. It is desirable that the fine particles 26 are formed of a material that has high rigidity and is not easily crushed. As the material of the fine particles 26, for example, an inorganic material such as glass, a conductive material such as carbon or aluminum, or an organic material such as silicon resin or acrylic resin can be used. In addition, a material in which one layer or a plurality of coating layers is provided on the surface of a particle serving as a nucleus can be used. Furthermore, a plurality of types of fine particles formed of different materials may be dispersed. The diameters of the fine particles 26 are preferably substantially the same. However, when the fine particles 26 are formed of a deformable material, the particle sizes may be slightly different.

  As shown in FIG. 27, the unsealed flow rate sensor 100a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insert piece 11 is adjusted. At this time, as shown in FIG. 27, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning projection 11 a of the insert piece 11.

As illustrated in FIG. 28, when the first semiconductor chip 3 is pressed downward by being pressed by the partitioning protrusion 11 a of the insert piece 11 and the thickness of the first adhesive 5 is reduced, the first semiconductor chip 3 is reduced. The fine particles 26 of the adhesive layer 5 </ b> A are sandwiched between the back surface 3 b and the top surface of the lead frame 1.
Since the fine particles 26 are not crushed or hardly crushed, the pressing force by the first semiconductor chip 3 is supported by the lead frame 1 through the fine particles 26.

For this reason, the reaction force to the first semiconductor chip 3 from the region 5a of the adhesive layer 5A corresponding to the partitioning projection 11a of the insert piece 11 arranged around the diaphragm 30, and other adhesive layer 5A The difference between the reaction force from the region 5b to the first semiconductor chip 3 is reduced. Therefore, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.
As described above, in the fifth embodiment, the adhesive layer 5 </ b> A containing the fine particles 26 interposed between the back surface 3 b of the first semiconductor chip 3 and the top surface of the lead frame 1 serves as a local part of the first adhesive 5. It functions as a typical collapse prevention mechanism 20E.
Therefore, the fifth embodiment also has the same effect as the first embodiment.

--Embodiment 6--
With reference to FIGS. 29-32, the flow sensor of Embodiment 6 of this invention is demonstrated.
29 is a plan view showing a flow sensor mounting structure in a state in which a resin is removed, showing a sixth embodiment of the flow sensor according to the present invention, and FIG. 30 is a XXX-XXX of the flow sensor shown in FIG. It is line sectional drawing. FIG. 31 is a cross-sectional view of a main part for explaining a method of housing the semiconductor chip having the flow rate detecting unit shown in FIG. 30 in a mold and molding the resin. FIG. It is a figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip.
In the sixth embodiment, a support plate 27 is disposed between the first semiconductor chip 3 and the lead frame 1 with respect to the flow rate sensor shown in the first embodiment, and the first semiconductor chip 3 and the second semiconductor are disposed on the support plate 27. The difference is that the chip 4 is mounted. However, the groove 29 provided in the support member constitutes an adhesive flow structure in which the first adhesive 5 flows, and thereby functions as a local crush prevention mechanism 20A of the first adhesive 5. In this case, the operation is the same as that of the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and the same structures as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 29 and 30, a support plate 27 is mounted on the lead frame 1, and the first semiconductor chip 3 and the second semiconductor chip 4 are mounted on the support plate 27.
A groove 29 is formed on the support plate 27 on the upper surface side. The groove 29 is formed from the inside of the first semiconductor chip 3 to the outside of the one side surface 3 c of the first semiconductor chip 3. The first adhesive 5 is disposed above the groove 29 inside the one side surface 3 c of the first semiconductor chip 3.

  The lead frame 1 and the support plate 27 are bonded by a third adhesive 28. As the third adhesive 28, for example, a thermosetting resin such as an epoxy resin or a phenol resin, or a thermoplastic resin such as polycarbonate or polyethylene terephthalate can be used.

  As shown in FIG. 31, the unsealed flow rate sensor 100 a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insertion piece 11 is adjusted. At this time, as shown in FIG. 32, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning projection 11 a of the insert piece 11. For this reason, the pressing force larger than the other area | region 5b acts on the area | region 5a of the 1st adhesive agent 5 corresponding to the protrusion part 11a for a partition. However, since the groove portion 29 is formed on the support plate 27 from the inner side of the first semiconductor chip 3 to the outer side of the one side surface 3c of the first semiconductor chip 3, the first adhesion having a low elastic modulus and high fluidity. The agent 5 flows into the groove 29.

Therefore, although the thickness of the first adhesive 5 is reduced as a whole, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.
As described above, in the sixth embodiment, the groove 29 formed in the support frame 27 forms an adhesive flow structure in which the first adhesive 5 flows. It functions as a crush prevention mechanism 20A.
Therefore, also in Embodiment 6, there exists an effect similar to Embodiment 1.

Note that the shape and structure of the groove 29 can be appropriately modified and applied in the same manner as the groove 18 of the first embodiment.
The structure in which the support plate 27 is interposed between the lead frame 1 and the first semiconductor chip 3 can also be employed in the second to sixth embodiments.

--Embodiment 7--
A flow sensor according to a seventh embodiment of the present invention will be described with reference to FIGS.
33 is a plan view of a flow sensor according to a seventh embodiment of the present invention. FIG. 34 is a cross-sectional view of the flow sensor illustrated in FIG. 33 taken along the line XXXIV-XXXIV. 35 is a plan view showing a mounting structure of the flow rate sensor in a state where the resin is removed from the flow rate sensor shown in FIG. 34. FIG. 36 is a cross-sectional view of the flow rate sensor shown in FIG. 35 taken along the line XXXVI-XXXVI. FIG. FIG. 37 is a cross-sectional view of an essential part for explaining a method of housing the semiconductor chip having the flow rate detection unit shown in FIG. 34 in a mold and molding the resin, and FIG. FIG. 39 is an enlarged view in the vicinity of the local crush prevention mechanism of the adhesive, and FIG. 39 is a diagram showing a state in which the pressing force by the mold acts on the semiconductor chip in FIG.
The flow rate sensor according to the seventh embodiment is different from the first embodiment in that the first semiconductor chip 3 includes a control circuit portion and the groove portion 18 formed in the lead frame 1 is longer than the first semiconductor chip 3. It is the point formed corresponding to a pair of side surface which opposes in (X) direction. However, the groove portion 18 provided in the lead frame 1 constitutes an adhesive flow structure in which the first adhesive 5 flows, and thereby functions as a local collapse prevention mechanism 20A of the first adhesive 5. In this respect, it has the same operation as that of the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and the same structures as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

The first semiconductor chip 3 includes a flow rate detection unit 2 formed on the diaphragm 30 and a control circuit unit 35 that controls the flow rate detection unit 2 to measure the flow rate. The diaphragm 30 is formed substantially at the center of the first semiconductor chip 3 in the longitudinal (X) direction. The control circuit unit 35 is connected to the lead frame 1 by a wire 7. The flow rate detection unit 2 is exposed from an opening 14 a formed in the resin 14, and the control circuit unit 35 and the wire 7 are covered with the resin 14.
On the upper surface side of the lead frame 1, a pair of groove portions 18 separated in the longitudinal (X) direction are formed. Each groove portion 18 is formed from the inside of the first semiconductor chip 3 to the outside of the one side surface 3c.
The back surface 3b of the first semiconductor chip 3 is bonded to the lead frame 1 with the first adhesive 5 over the entire surface.

  As shown in FIG. 37, the unsealed flow rate sensor 100a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insert piece 11 is adjusted. At this time, as illustrated in FIG. 38, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning protrusion 11 a of the insert piece 11. For this reason, the pressing force larger than the other area | region 5b acts on the area | region 5a of the 1st adhesive agent 5 corresponding to the protrusion part 11a for a partition. However, the lead frame 1 is formed with a pair of groove portions 18 formed from the inside of the first semiconductor chip 3 to the outside of the one side surface 3 c of the first semiconductor chip 3. For this reason, the first adhesive 5 having a low elastic modulus and high fluidity flows into each groove 18 as shown in FIG.

Therefore, although the thickness of the first adhesive 5 is reduced as a whole, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.
As described above, in the seventh embodiment, the pair of grooves 18 formed in the lead frame 1 constitutes the adhesive flow structure 20A through which the first adhesive 5 flows. It functions as a local crush prevention mechanism 20A.
Therefore, the same effects as in the first embodiment are also obtained in the seventh embodiment.

  Note that the shape and structure of the groove 18 can be appropriately modified and applied in the same manner as the groove 18 of the first embodiment.

--Eighth embodiment--
With reference to FIGS. 40-43, the flow sensor of Embodiment 8 of this invention is demonstrated.
40 is a plan view showing a flow sensor mounting structure in a state where a resin is removed, showing an eighth embodiment of the flow sensor according to the present invention, and FIG. 41 is XXXXI-XXXXI of the flow sensor shown in FIG. It is line sectional drawing. FIG. 42 is a cross-sectional view of a main part for explaining a method of housing the semiconductor chip having the flow rate detection unit shown in FIG. 41 in a mold and molding the resin, and FIG. It is a figure which shows the state which the pressing force by the metal mold | die acted on the semiconductor chip.
The eighth embodiment is characterized in that a material having a different Young's modulus is used as the first adhesive 5 as the local crush prevention mechanism 20F of the first adhesive 5. Hereinafter, this characteristic structure will be mainly described. In the structure similar to that of Embodiment 1, the same reference numerals are assigned to the corresponding members, and the description thereof is omitted.

  As shown in FIG. 41, an adhesive layer 5 </ b> B is formed between the lead frame 1 and the first semiconductor chip 3. The adhesive layer 5B is provided to the first adhesive 5 provided around the diaphragm 30 on the back surface 3b of the first semiconductor chip 3 and to the one side surface 3c of the first semiconductor chip 3 adjacent to the first adhesive 5. And a fourth adhesive 32 formed. The fourth adhesive 32 has a lower Young's modulus or a lower elastic modulus than the first adhesive 5, and thereby constitutes a local crush prevention mechanism 20 </ b> F of the first adhesive 5 as described below. .

  As shown in FIG. 42, the unsealed flow rate sensor 100a is accommodated in the cavity 13 of the upper mold 8 and the lower mold 9, and the height of the insert piece 11 is adjusted. At this time, as shown in FIG. 43, the periphery of the diaphragm 30 on the main surface 3 a side of the first semiconductor chip 3 is pressed by the partitioning protrusion 11 a of the insert piece 11. For this reason, a larger pressing force is applied to the region 5a of the first adhesive 5 corresponding to the partition protrusion 11a than the fourth adhesive 32 not corresponding to the partition protrusion 11a.

  However, since the fourth adhesive 32 has a Young's modulus lower than that of the first adhesive 5 or a low elastic modulus, it is easily crushed. For this reason, the difference between the reaction force from the region 5a of the first adhesive 5 to the first semiconductor chip 3 and the reaction force from the fourth adhesive 32 to the first semiconductor chip 3 is reduced. Therefore, local crushing does not occur around the diaphragm 30. As a result, it is possible to prevent the first semiconductor chip 3 from being bent and to prevent the first semiconductor chip 3 from being distorted or cracked.

As described above, in the eighth embodiment, the adhesive layer 5B interposed between the first semiconductor chip 3 and the lead frame 1 constitutes an adhesive flow structure in which the first adhesive 5 flows. Thereby, the function as the local crushing prevention mechanism 20F of the first adhesive 5 is achieved.
Therefore, the same effects as in the first embodiment are also obtained in the eighth embodiment.

  In the eighth embodiment, similarly to the first embodiment, the groove 18 may be formed in the lead frame 1 corresponding to the one side surface 3 c or the outer peripheral surface of the first semiconductor chip 3. Further, the fine particles 26 may be dispersed in the first adhesive 5 as in the fifth embodiment.

  As described above, in the first to eighth embodiments of the present invention, in order to prevent the deformation of the semiconductor chip caused by the area of the adhesive corresponding to the peripheral area of the diaphragm being crushed, the adhesive is locally crushed. It has. For this reason, it is possible to prevent the first semiconductor chip from being bent and deformed by pressing the mold in resin sealing, and to prevent the first semiconductor chip 3 from being distorted or cracked.

  In each of the above embodiments, the first semiconductor chip is prevented from being bent and deformed by pressing the mold in resin sealing. However, in addition to this, when the flow rate sensor 100 is transported or to the internal combustion engine, etc. It is also effective when other members or attachments are in contact with the diaphragm 30 of the flow sensor 100 during attachment. Therefore, even when resin sealing to the unsealed flow sensor 100a is performed by a method other than molding, an effect is exhibited.

Further, the present invention is not limited to the above embodiments, and various modifications can be applied within the scope of the gist of the invention.
For example, in each of the above embodiments, the first adhesive 5 is exemplified in a structure in which the first adhesive 5 is not provided in a region corresponding to the recess 31 where the diaphragm 30 of the first semiconductor chip 3 is formed. Alternatively, the first adhesive 5 may be provided.

  Moreover, although the example in which the control circuit unit is formed in the first semiconductor chip 3 is illustrated as the seventh embodiment, the control circuit unit may be provided in the first semiconductor chip 3 also in other embodiments.

  As a local crush prevention mechanism of the first adhesive 5 in which the local crush prevention mechanisms 20A to 20F of the first adhesive 5 exemplified in the first to eighth embodiments are partially or entirely combined. Good.

  In short, the back surface of a semiconductor chip in a flow rate sensor in which a semiconductor chip having a diaphragm on the main surface on which a flow rate detection unit is formed is bonded to a support substrate with an adhesive and is sealed with resin in a state where the flow rate detection unit is exposed. Any adhesive flow structure that allows the adhesive to flow may be provided on either the side, the upper surface of the support substrate, or between the semiconductor chip and the support substrate.

DESCRIPTION OF SYMBOLS 1 Lead frame 2 Flow volume detection part 3 1st semiconductor chip 3a Main surface 3b Back surface 3c One side surface 4 Second semiconductor chip 5 First adhesive 5A, 5B Adhesive layer 6 Second adhesive 11, 11A Insertion piece 11a Partition protrusion 11a Part 11b Protruding part for pressing 14 Resin 14a, 14b Opening (resin non-formation region)
18 Groove 20A to 20F Crush Prevention Mechanism 22 Gap 26 Microparticle 27 Support Plate 29 Groove 30 Diaphragm 31, 33 Concave 32 Fourth Adhesive 35 Control Circuit 100 Flow Sensor 100a Unsealed Flow Sensor S Space K Space

Claims (20)

A support substrate;
Mounted on the support substrate, having a main surface on which a flow rate detection unit is formed and a back surface opposite to the main surface, a recess is formed on the back surface, and a diaphragm is formed on the recess on the main surface A semiconductor chip,
A resin that exposes the flow rate detection unit and covers the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip;
An adhesive that is provided between at least the diaphragm peripheral region and the support substrate corresponding to the diaphragm peripheral region on the back surface of the semiconductor chip, and bonds the semiconductor chip and the support substrate;
An adhesive flow structure in which the adhesive flows, provided on at least one of the back surface of the semiconductor chip, the top surface of the support substrate, or the back surface of the semiconductor chip and the top surface of the support substrate; A flow sensor comprising: The flow sensor according to claim 1,
The adhesive flow structure is a flow sensor including a groove provided on an upper surface of the support substrate. The flow sensor according to claim 2,
A flow sensor in which a part of the adhesive flows and is accommodated in the groove. The flow sensor according to claim 3,
The groove portion is a flow rate sensor provided from the inner side of at least one side surface of the semiconductor chip to the outer side of the one side surface. The flow sensor according to claim 4, wherein
The groove portion is a flow sensor provided along the peripheral side surface of the semiconductor chip from the inside of the peripheral side surface to the outside of the peripheral side surface. The flow sensor according to claim 1,
The adhesive flow structure is a flow sensor including a groove provided in the back surface of the semiconductor chip. The flow sensor according to claim 6, wherein
A flow sensor in which a part of the adhesive flows and is accommodated in the groove. The flow sensor according to claim 7,
The groove portion is a flow rate sensor provided on the inner side of the peripheral side surface of the semiconductor chip on the back surface of the semiconductor chip. The flow sensor according to claim 1,
The adhesive flow structure includes a gap portion of the adhesive provided outside the adhesive provided in a peripheral area of the diaphragm. The flow sensor according to claim 9,
A flow rate sensor in which a part of the adhesive flows and is accommodated in the gap of the adhesive. The flow sensor according to claim 9,
The gap portion of the adhesive is a flow sensor provided from the inside of at least one side surface of the semiconductor chip to the outside of the one side surface. The flow sensor according to claim 1,
The adhesive flow structure includes the adhesive formed corresponding to the diaphragm peripheral region and a second adhesive having a Young's modulus different from that of the adhesive provided outside the diaphragm peripheral region. Including flow sensor. The flow sensor according to claim 12,
The flow rate sensor, wherein the second adhesive has a Young's modulus lower than that of the adhesive formed corresponding to the diaphragm peripheral region. A support substrate;
Mounted on the support substrate, having a main surface on which a flow rate detection unit is formed and a back surface opposite to the main surface, a recess is formed on the back surface, and a diaphragm is formed on the recess on the main surface A semiconductor chip,
A resin that exposes the flow rate detection unit and covers the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip;
An adhesive that is provided between at least the diaphragm peripheral region on the back surface of the semiconductor chip and the support substrate corresponding to the diaphragm peripheral region, and bonds the semiconductor chip and the support substrate;
The resin has at least one of a first resin non-formation region that exposes the flow rate detection unit and at least one part of the main surface of the semiconductor chip that is spaced from the first resin non-formation region. A flow sensor comprising a second resin non-formation region. The flow sensor according to claim 14,
A flow sensor further comprising a connection lead, wherein one end of the connection lead is connected to the semiconductor chip at least in the vicinity of the first resin non-formation region rather than the second resin non-formation region. A support substrate;
Mounted on the support substrate, having a main surface on which a flow rate detection unit is formed and a back surface opposite to the main surface, a recess is formed on the back surface, and a diaphragm is formed on the recess on the main surface A semiconductor chip,
A resin that exposes the flow rate detection unit and covers the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip;
An adhesive layer provided between at least the diaphragm peripheral region on the back surface of the semiconductor chip and the support substrate corresponding to the diaphragm peripheral region, and bonding the semiconductor chip and the support substrate;
The said adhesive bond layer is a flow sensor containing an adhesive agent and the microparticles | fine-particles disperse | distributed in the said adhesive agent. The flow sensor according to claim 1-16,
Furthermore, a flow sensor provided with the control circuit part which controls the said flow volume detection part. The flow sensor according to claim 17,
The control circuit unit is a flow sensor formed in the semiconductor chip. The flow sensor according to claim 17,
A flow sensor comprising a control semiconductor chip having the control circuit unit. A support substrate;
Mounted on the support substrate, having a main surface on which a flow rate detection unit is formed and a back surface facing the main surface, a recess is formed on the back surface side, and a diaphragm is formed on the recess on the main surface side A formed semiconductor chip; and
A resin that exposes the flow rate detection unit and covers the main surface of the semiconductor chip and the peripheral side surface of the semiconductor chip;
An adhesive that is provided between at least the diaphragm peripheral region on the back surface of the semiconductor chip and the support substrate corresponding to the diaphragm peripheral region, and bonds the semiconductor chip and the support substrate;
A flow sensor comprising a crush prevention mechanism for preventing local crushing of the adhesive in order to prevent deformation of the semiconductor chip caused by crushing the area of the adhesive corresponding to the peripheral area of the diaphragm.

Images