JP2009010942A - Piezoelectric component and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate infiltration of resin into an airtight space portion and to stop a terminal electrode etc., from being cut owing to dicing by setting the thickness of a resin sheet used for a resin sealing stage while taking into consideration a printing shift between dicing marks printed on top and reverse surfaces of an aggregate substrate. <P>SOLUTION: A piezoelectric component manufacturing method includes a stage of flip-chip mounting a SAW chip 2 with a bump 5 on a ceramic substrate 3, a stage of sticking a resin sheet 6 on the aggregate substrate after mounting by heat softening and further performing resin sealing by heat curing, and a stage of providing a dicing mark on the reverse surface of the aggregate substrate after mounting which was sealed/cured and cutting the aggregate substrate into pieces 1 using the dicing mark. The thickness of the resin sheet 6 before the resin-sealing stage is defined by a predetermined relational expression based upon a chip size, a top/reverse shift, a cutting margin, a SAW device size, a resin sealing layer thickness, etc. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a SAW device in which a SAW chip is sealed with a resin after a piezoelectric component, for example, a surface acoustic wave (SAW) chip is mounted on a mounting substrate face down using a bump. In addition, the present invention relates to a piezoelectric component and a method for manufacturing the same, which prevent generation of defective products due to resin penetration failure, shift during dicing, and the like.

  A surface acoustic wave device (SAW device) has a configuration in which patterns such as comb-like electrodes (IDT electrodes) and connection pads are arranged on a piezoelectric substrate such as crystal or lithium tantalate. For example, a high-frequency electric field is applied to IDT electrodes. When applied, the surface acoustic wave is excited, and the surface acoustic wave is converted into a high-frequency electric field by a piezoelectric action to be mounted on a mobile phone or the like that obtains filter characteristics. In this SAW device, a predetermined gap (hollow part, airtight space) is required around the comb electrode part. Therefore, conventionally, SAW chips are die-bonded face-up on a ceramic substrate, electrically connected by wire bonding, and then covered with a metal cap and seam-welded or solder-sealed for packaging.

  Recently, in order to reduce the size of SAW devices, SAW chips are flip-chip bonded (face-down bonding) to a wiring board with Au (gold) bumps or solder bumps, and sealed with resin or the like to form a small package device. It is composed.

In addition, in order to reduce the size and height of the SAW device, a gap is formed around the comb electrode part, and the entire piezoelectric wafer on the comb electrode side is sealed with resin while maintaining the gap to form an external connection electrode. after ultra-small chip size package formed by separating the individual devices by dicing: SAW device (C hip S ize P ackage abbreviated CSP) is proposed.

  CSP-related technologies related to SAW devices are described in, for example, Japanese Patent No. 3702961 (Epson Toyocom), Japanese Patent No. 3687414 (Epson Toyocom), and Japanese Patent No. 3825475 (Toshiba).

Conventional Example 1
First, in Japanese Patent No. 3702916 (Patent Document 1), as shown in FIGS. 7A and 7B, an insulating substrate 103, an external electrode 104 for surface mounting disposed on the bottom of the insulating substrate 103, and A mounting substrate 102 provided with a wiring pattern 105 disposed on the insulating substrate 103 and electrically connected to the external electrode 104; a piezoelectric substrate 118; an IDT electrode 117 formed on one surface of the piezoelectric substrate 118; and the wiring The SAW chip 115 is constituted by the pattern 105 and the connection pad 116 connected via the conductor bump 110. Then, the SAW chip 115 is flip-chip mounted on the mounting substrate 102 in a face-down state, and is covered with a sealing resin 131A from the outer surface of the SAW chip 115 to the upper surface of the mounting substrate 102, whereby the IDT electrode 117 and the mounting substrate 102 are covered. A surface-mounted SAW device is formed by forming an airtight space S therebetween.

And, as shown in FIGS. 8A and 8B, the SAW device manufacturing method of Conventional Example 1 is
A flip chip mounting step of flip chip mounting the SAW chip 115 on the mounting substrate 102 by connecting the wiring pattern 105 and the connection pad 116 via the conductor bump 110;
A resin sheet 130 having a larger area than the upper surface of the SAW chip 115 is placed on the upper surface of the SAW chip 115, and the resin sheet 130 is softened from one end to the other end of the mounting substrate 102 while pressing the resin sheet 130 with the pressing roll 151. A laminating step of covering the outer surface of the SAW chip 115 with a resin while securing the airtight space S by applying pressure by the side roll 152;
A press molding step of curing the resin sheet 130 while suppressing expansion of gas in the airtight space S by heating the SAW chip 115 laminated on the outer surface with the resin sheet 130 while pressing it;
And a post-curing step of heating the SAW device 101 that has undergone the press-molding step at a temperature and time at which the resin is completely cured.

Here, the thickness tr of the resin sheet 130 before the laminating step is
L / [(X + Gx) (Y + Gy)] ≦ tr (1)
However, L = (X + Gx) (Y + Gy) (H + T + A) −XYT−XYA− [XVyA + YVxA + (4VxVyA) / 3]
(L: Volume of resin sheet necessary for sealing one SAW chip outer surface, X: Length of one side of SAW chip, Y: Length of other side of SAW chip, Gx: Adjacent in X direction Distance between SAW chips, Vx: Distance from the dicing cut edge extending in the Y direction to the side surface of the nearest SAW chip, Gy: Spacing between adjacent SAW chips in the Y direction, Vy: Distance from the dicing cut edge extending in the X direction. Distance to the side surface of the SAW chip, H: thickness of the resin positioned on the upper surface of the SAW chip after the outer surface of one SAW chip is completely covered with a resin sheet, T: thickness of the piezoelectric substrate, A: from the upper surface of the mounting substrate The distance between the bottom surface of the piezoelectric substrate).

  In the conventional example 1, after the post-curing step, individual SAW devices are obtained by dicing along the dicing margin from the surface side (resin sealing side) with a dicing plate having a width D.

  However, the SAW device manufacturing method of Conventional Example 1 shown in Patent Document 1 requires a press molding step of curing the resin sheet after the laminating step of covering the outer surface of the SAW chip with the resin sheet, so that the entire manufacturing method is complicated. It becomes.

  Furthermore, when the aggregate substrate is cut into individual pieces (SAW devices), the back side of the electrode formed by printing on the ceramic substrate and the cut-off alignment mark due to misalignment from the resin sealing surface There have been problems such as electrode positions being displaced and back terminal electrodes being damaged.

  In addition, in order to avoid this problem, when the alignment mark is formed on the back terminal electrode side of the collective substrate and cut, the sealed resin void may be cut, and a hollow portion is formed around the outer periphery of the product. There was a problem that was exposed.

Conventional example 2
Moreover, in the manufacturing method of the SAW device disclosed in Japanese Patent No. 3688414 (Patent Document 2), as shown in FIGS. 9A and 9B,
In the manufacturing method of the SAW device 201 in which the SAW chip 215 is flip-chip mounted on the mounting substrate 202 and the outer surface of the SAW chip 215 is sealed with the resin 231 to form the airtight space S.
Flip-chip mounting the electrode pads 216 provided on the SAW chip 215 and the connection pads 205 provided on the mounting substrate 202 using the conductor bumps 210;
Placing the resin sheet 230 on the upper surface of the SAW chip 215 mounted on the mounting substrate 202;
A mounting substrate 202 on which the SAW chip 215 is mounted and the resin sheet 230 is placed on the top surface of the SAW chip 215 is placed in a hermetic container, and the resin sheet 230 is pressurized while being heated. A laminating step of covering the outer surface of the SAW chip 215 with the resin sheet 230 while securing,
A press molding step of curing the resin sheet 230 while maintaining the airtight space S by maintaining the pressure and heating state of the laminating step;
A post-curing step of heating at a temperature and time for completely curing the resin sheet 230,
In the laminating step, the sealed container 250 is partitioned into at least two spaces by a partition member, and the first space is mounted with the SAW chip 215 mounted thereon and the resin sheet 230 placed on the top surface of the SAW chip 215. The substrate 202 is disposed, and the atmosphere is maintained at a reduced pressure or a vacuum state, and the resin sheet 230 is formed by pressing the partition member against the first space side by applying pressure from the second space side. It is characterized by applying pressure to the mounting substrate 202 side.

Here, the thickness tr of the resin sheet 230 during the laminating step is
L / {(X + Gx) (Y + Gy)} ≦ tr (2)
However, L = (X + Gx) (Y + Gy) (H + T + A) −XYA− {XVyA + YVxA + (4VxVyA) / 3}
(L: Volume of resin sheet necessary for sealing one SAW chip outer surface, X: Length of one side of SAW chip, Y: Length of other side of SAW chip, Gx: Adjacent in X direction SAW chip interval, Vx: distance from dicing cut edge extending in Y direction to nearest SAW chip side face, Gy: gap between adjacent SAW chips in Y direction, Vy: nearest SAW chip from dicing cut edge extending in X direction H: The thickness of the resin located on the upper surface of the SAW chip after the outer surface of one SAW chip is completely covered with the resin sheet, T: The thickness of the piezoelectric substrate, A: From the upper surface of the mounting substrate to the piezoelectric substrate The distance to the bottom surface).

  However, the SAW device manufacturing method of Conventional Example 2 shown in Patent Document 2 also requires a laminating step of covering the outer surface of the SAW chip with a resin sheet, similar to that of Patent Document 1 (Conventional Example 1), And it is indispensable to divide the sealed container in which the mounting substrate is arranged in this laminating process into at least two spaces by a partition member, and further requires a press molding process for curing the resin sheet after the laminating process. The entire manufacturing method becomes complicated. Furthermore, since dicing was performed from the front surface side of the mounting substrate at the time of division into individual SAW devices, there were problems such as cutting of external electrodes due to printing misalignment between the front and back surfaces of the SAW device.

Conventional example 3
Furthermore, in the manufacturing method of the electronic component (SAW device) of Conventional Example 3 shown in Japanese Patent No. 3825475 (Patent Document 3), the electronic component (SAW device) shown in FIG. In contrast, the step of positioning a plurality of functional elements 303 at a predetermined position by a face-down bonding method, and maintaining a predetermined distance between the functional elements 303 and the assembly of the wiring boards 301 via a conductive bonding member 306. A step of assembling, a step of disposing a heating and melting mold member 311 with respect to the assembly of the wiring board 301 and the functional element 303, and the heating while leaving a gap 310 between the wiring board 301 and the functional element 303. A step of heating and melting the melting mold member 311, and an assembly of the plurality of wiring boards 301 together with the heating melting mold member 311. And obtaining a discrete electronic components and, in manufacturing.

However, in the method of manufacturing the electronic component (SAW device) of Conventional Example 3 shown in Patent Document 3, the heat-melting mold part (flaky resin) is once heated and melted, so that impurities such as silicon, filler, and moisture generated during melting And molten resin penetrated into the gap (gap), which was a cause of defective products. In addition, as in the above-mentioned Patent Documents 1 and 2, since dicing was performed from the front surface side when dividing into individual electronic components (SAW devices), problems such as breakage of external electrodes mounted on the rear surface side occurred. It was.
Japanese Patent No. 3702961 Japanese Patent No. 3689414 Japanese Patent No. 3825475

  The problem to be solved by the present invention is that the resin is infiltrated into the airtight space at the time of resin sealing of the SAW device that constitutes the piezoelectric component, and a terminal due to printing deviation of the dicing mark printed on the front and back surfaces of the collective substrate This is a cut of an electrode or the like.

In order to solve the above-described problems, the invention of claim 1 includes a step of flip-chip mounting a bumped SAW chip on a collective substrate, and heating a resin sheet having a larger area than the upper surface of the collective substrate on the assembled collective substrate. A process of softening and pasting while leaving a hollow part, and further sealing with resin by heat curing, and a dicing mark is provided on the back surface of the assembled and mounted assembly board, and the assembly board is used by using the dicing mark In a method of manufacturing a piezoelectric component (SAW device) comprising:
The thickness t of the resin sheet before the resin sealing step is
t> (i × k × H− (4 ((g−a) / 2 × (j−b) / 2) × 1/3 × d) + ((((g−a) / 2 × b) × 2) × d)
+ ((((J−b) / 2) × a) × 2) × d)) − (a × b × c) + (a × b × d)) / (g × i)
(Where a: the width of the chip (SAW chip)
b: Depth of chip
c: Chip thickness
d: Gap between chip and substrate
e: External shape (width) of product (piezoelectric component)
f: Product outline (depth)
g: Product outline + cutting width (width)
i: Product outline + cutting depth (depth)
j: Product outline-front / back displacement (width)
k: Product outline-front / back displacement (depth)
H: Resin sealing layer thickness)
It is characterized by being.

  According to this, when the resin sealing process is carried out, the thickness of the resin sheet to be used is set to an appropriate value, so that the softened resin filled in the valleys between the SAW chips can reach the bottom of the SAW chip. As a result, the airtight space is reliably formed by spreading, and there is no possibility of breaking the terminal electrode or the like when dividing into SAW device pieces by dicing.

  According to a second aspect of the present invention, in the first aspect, the resin sealing step includes a step of placing the assembled substrate mounted on a lower mold, and an area larger than an upper surface of the collective substrate on the placed collective substrate. A step of placing a large resin sheet, a step of degassing and depressurizing the inside of the decompression vessel after disposing the upper die and the decompression vessel on the lower die, and heating the resin sheet above the softening temperature, A process of pressing and pasting and sealing with the upper mold, a process of removing the upper mold and the decompression container from the lower mold after returning the inside of the decompression container to atmospheric pressure, and the sealed aggregate substrate And a step of removing from the lower mold.

  Thereby, when implementing a resin sealing process, a predetermined airtight space can be formed reliably.

  The invention of claim 3 is characterized in that, in claim 1, the softened resin sheet has a viscosity of 7,000 to 20,000 Pa · s.

  Thereby, it is possible to prevent the resin from entering the airtight space at the time of resin sealing.

  The invention of claim 4 is characterized in that, in claim 1, the temperature at which the resin sheet is softened by heating is 30 ° C. to 150 ° C.

  Thereby, a resin sheet can be softened reliably.

  The invention of claim 5 is characterized in that, in claim 1, the resin sheet is an epoxy resin.

  The invention of claim 6 is characterized in that, in claim 2, the pressure in the decompression vessel at the time of deaeration and decompression is 0.01 to 0.05 atm.

  Thereby, similarly, the resin sheet can be reliably softened.

  A seventh aspect of the invention is characterized in that, in the first to sixth aspects, the piezoelectric component is a SAW device.

  Dicing without effectively damaging the terminal electrodes etc. to individual piezoelectric parts while preventing resin penetration into the hollow part (airtight space) around the IDT electrode during resin sealing. Can be divided.

  Hereinafter, a method for manufacturing a piezoelectric component according to the present invention will be described in detail for a method for manufacturing an example of a surface-mounted surface acoustic wave device (hereinafter referred to as “SAW device”).

  FIG. 1 is a longitudinal sectional view of a SAW device 1 manufactured by a SAW device manufacturing method which is an embodiment of the piezoelectric component manufacturing method of the present invention.

This SAW device 1 (piezoelectric component) includes a ceramic substrate (insulating substrate) 3 formed by laminating several ceramics, and mounted on the upper surface of the ceramic substrate 3 via gold (Au) bumps 5, for example, tantalum. A SAW chip 2 made of lithium oxide (LiTaO ₃ ), an epoxy resin (resin sealing portion) 6 for resin-sealing the SAW chip 2, and an external terminal electrode 4 mounted on the bottom surface of the ceramic substrate 3. ing. And it seals with an epoxy resin so that the airtight space S may be formed between the IDT electrode 7 formed in the SAW chip 2 and the upper surface of the ceramic substrate 3.

  Here, the IDT electrode 7 formed on the SAW chip 2 excites a surface acoustic wave by applying a high frequency electric field from a lead terminal on the power supply side, and converts the surface acoustic wave into a high frequency electric field by a piezoelectric action. Filter characteristics can be obtained.

  Next, a method for manufacturing a SAW device according to an embodiment of the present invention will be described with reference to FIGS.

Manufacturing method (assembly process)
FIG. 2 shows a manufacturing method (assembly process) including a flip chip mounting process, a resin sealing process, and a dicing process for the SAW device according to the embodiment of the present invention.

  First, in order to manufacture the SAW device 1 shown in FIG. 1, the SAW chip 2 with the gold (Au) bumps 5 cut from the SAW wafer W on the ceramic substrate 3 is face-down as shown in FIG. -A mounting (collection) substrate 50 is manufactured by flip chip mounting by gold ultrasonic thermocompression bonding ((1) flip chip mounting process).

  Next, resin sealing is performed on the mounting substrate 50 on which the flip chip is mounted in a sealing process described later, and then the resin is cured ((2) resin sealing process).

Further, the resin surface is irradiated with a CO ₂ gas laser, and the product number, lot number, etc. are engraved and stamped ((3) laser stamping process).

  Next, based on the recognition pattern formed on the back surface of the mounting substrate 50 using a dicing saw, the mounting substrate is divided into individual SAW devices (pieces) 1 in a dicing process described later ((4) dicing process).

In addition, ( 5 ) Heat treatment process (heated at 150 ° C for 3 hours), ( 6 ) Leak test process (soaked in high boiling point fluorinate, etc.), ( 7 ) Measurement (inspection of whether or not the standardized frequency can be output) -After the taping (aggregating the divided SAW devices using embossed tape) process, ( 8 ) packing and shipping the SAW devices.

  In particular, the characteristic configuration (summary) of the SAW device manufacturing method according to the embodiment of the present invention is in 1) resin sealing step and 2) dicing step, which will be described in detail below.

Resin Sealing Step First, the resin sealing step will be described with reference to FIG.

  In this resin sealing step, as shown in FIG. 3, a decompression vessel 12 is used, and the lower mold 10 is placed inside the decompression vessel 12. The upper mold 11 housed in the upper and lower parts 11 is configured to move up and down.

  First, as shown in FIG. 3, a substrate (collected substrate) 50 on which the SAW chip 2 is mounted is placed on the lower mold 10. Next, the resin sheet 6 having a larger area than the upper surface of the collective substrate 50 is placed on the mounted substrate 50, the upper mold 11 and the decompression container 12 are disposed on the lower mold 10, and then the decompression container 12. The inside is degassed and depressurized to 0.01 to 0.05 atm. Then, the upper die 11 is lowered and the resin sheet 6 is heated and softened with a hot plate and pressed with the upper die 11 with, for example, a press pressure of 100 kg or more (press molding), and the resin sheet 6 is attached to the mounted substrate. The SAW chip 2 and the like are sealed with resin. After the resin sealing is completed, the mold (upper mold 11 and lower mold 10) is completely returned to atmospheric pressure, and then the upper mold 11 and the vacuum container 12 are removed from the lower mold 10 and sealed in an oven at 100 ° C. for 30 minutes. After the stopped product is heated and temporarily cured, the sealed product is removed from the lower mold 10 and the next process (laser marking process, dicing process) is performed.

  In particular, at the time of resin sealing of the SAW chip 2 and the like, as described above, the SAW element is composed of an IDT (comb tooth) electrode 7 and a SAW chip 2 (piezoelectric substrate) as shown in FIG. Since vibration propagates on the two surfaces, it functions as a SAW element. Therefore, how to seal the entire SAW chip 2 with resin while keeping the space S on the IDT electrode 7 is an extremely important factor.

  For example, when a narrow gap between the SAW chip 2 and the ceramic substrate 3 is sealed in the space with a low-viscosity liquid resin such as an underfill material, the liquid resin enters the space S from the gap due to a capillary phenomenon. Resulting in.

  In general, the viscosity of the sealing material is high, and if this gap is narrow, the time required for the resin to enter becomes longer, and a predetermined hollow (space) structure can be obtained, but when forming a hollow structure with a liquid resin, It is technically difficult because of the high viscosity and fast curing, and the low viscosity material in the resin is not separated (bleeded) until cured.

  On the other hand, when a resin sheet having a high viscosity is used for resin sealing as in the method of manufacturing a SAW device according to the embodiment of the present invention, the resin sheet is a gel-like material having no fluidity. And in liquid resin, the penetration | invasion to the gap of the resin component which cannot be avoided does not arise. For this reason, the height (gap from the top surface of the ceramic substrate to the upper press plate) that is pressed from the top surface of the resin sheet is adjusted using a spacer or height adjustment jig according to the volume of the resin sealing area. By doing so, it becomes possible to leave a predetermined hollow portion and seal it.

  In other words, by adjusting the amount of the resin sheet pushed by the upper press plate so that the volume of the resin sheet = product volume− (SAW chip volume + hollow part) + cutting distance, resin intrusion or leakage failure It can seal without generation | occurrence | production of.

Here, as a resin sheet used for this invention, an epoxy resin can be used, for example . This epoxy resin has a much higher viscosity than the liquid resin as shown in the graph showing the viscosity / temperature characteristics in FIG. 4. For example, a softened resin sheet has a viscosity of 7,000 to 20,000 Pa · s. Having a viscosity of In this state, since the resin sheet is in the form of a gel and has no fluidity, the resin is not mixed into the narrow gap due to the capillary phenomenon that is normally generated in the liquid resin. Therefore, when the pressing by the upper mold 11 shown in FIG. 3 is stopped, the resin sheet is not further deformed.

  Here, the heat softening temperature of the resin sheet is 30 ° C to 150 ° C, preferably 80 ° C to 100 ° C.

  Therefore, if the pushing amount of the upper die 11 is excessive, the volume of the hollow part (space) of the SAW device is reduced and the resin reaches the IDT electrode, so that the characteristic defect increases and the pushing amount is insufficient. The resin does not spread sufficiently, resulting in a leak failure.

  Therefore, by appropriately adjusting the pushing amount, it is possible to manufacture a SAW device free from resin penetration and leakage defects.

  According to the knowledge of the present inventor, the lower the pressure in the decompression vessel (for example, 0.05 atm), the smaller the leakage defect, the temperature range of the heating temperature of 80 ° C. or higher (for example, 80 ° C. to 100 ° C.) and A heating time of at least 5 minutes or more is suitable for sealing with the material, and if the amount of pressing of the upper die is excessive, the volume of the hollow portion decreases and the resin reaches the IDT electrode, resulting in poor characteristics. On the other hand, if the push-in amount is insufficient, the resin does not spread sufficiently and a leak failure occurs. By appropriately adjusting the push-in amount, a SAW device free from resin permeation and leakage failure can be obtained.

Dicing Step and Laser Stamping Process Furthermore, in the SAW device manufacturing method according to the embodiment of the present invention, laser marking is performed after the resin sealing step and the dicing step . This eliminates the misalignment of the seal .

  In the SAW device manufacturing method, individual product units (SAW device outer shape + dicing margin) constituting the aggregate substrate 50 are arranged in a continuous state in the aggregate substrate, and are illustrated on a linear extension line of the dicing margin. Dicing alignment marks (dicing marks) having a recognition pattern as shown in FIG.

  In this dicing process, when the resin-encapsulated SAW mounting substrate (collective substrate) 50 is divided into individual SAW devices 1 with a dicing saw, as shown in FIG. 5, the edge of the back surface of the mounting substrate (ceramic substrate) A recognition pattern (dicing mark) printed vertically and horizontally is used.

  Even if there is a deviation between the recognition patterns printed on the front and back surfaces of the mounting substrate 50 due to the recognition pattern printed on the back surface of the mounting substrate, the terminal electrodes, external electrodes, etc. mounted on the back surface are cut or misaligned. Without being generated, it can be divided into individual SAW devices (pieces) having a predetermined size (for example, 2.0 mm × 1.6 mm).

Selection of Resin Sheet Thickness In the SAW device manufacturing method according to an embodiment of the present invention, in order to manufacture the individual SAW devices without defects by surely carrying out the characteristic resin sealing step and dicing step described above, The resin sheet thickness t before resin sealing is calculated according to the formula (3) described in (1), and is used for its manufacture.

t> (i × k × H− (4 ((g−a) / 2 × (j−b) / 2) × 1/3 × d) + ((((g−a) / 2 × b) × 2) × d)
+ ((((J−b) / 2) × a) × 2) × d)) − (a × b × c) + (a × b × d)) / (g × i) (3)
In the above formula (3),
a: Chip (SAW chip) width b: Chip depth c: Chip thickness d: Gap between chip and substrate e: External shape (width) of product (SAW device)
f: Product outline (depth)
g: Product outline + cutting width (width)
i: Product outline + cutting depth (depth)
j: Product outline-front / back displacement (width)
k: Product outline-front / back displacement (depth)
H: Resin sealing layer thickness t: Resin sheet thickness (see FIGS. 6A and 6B).

  By selecting the resin sheet thickness t used for resin sealing as in the above formula (3), even if there is a printing misalignment between the recognition patterns shown in FIG. After cutting into devices, a predetermined resin sealing region can be secured.

  The piezoelectric component and the manufacturing method thereof of the present invention can be used for manufacturing a piezoelectric component such as a SAW device or a piezoelectric thin film filter in which accurate resin sealing and dimensions and shape after dicing are indispensable.

It is a longitudinal cross-sectional view of the SAW device (piezoelectric component) divided | segmented separately by the manufacturing method of the SAW device which is an Example of the manufacturing method of the piezoelectric component of this invention. It is a conceptual diagram of the manufacturing method of the SAW device of the Example of this invention. It is a conceptual diagram of the resin sealing process which comprises a part of manufacturing method of the SAW device of the Example shown in FIG. It is a graph which shows the viscosity and temperature characteristic of the resin sheet used at the resin sealing process which comprises a part of manufacturing method of the SAW device of the Example of this invention. It is the plane (back surface) figure of the mounting board | substrate which printed the recognition pattern divided | segmented at the dicing process which comprises a part of manufacturing method of the SAW device of the Example of this invention on the back surface. A longitudinal sectional view (FIG. 6 (a)) and a plan view (FIG. 6 (b)) showing respective specifications of the SAW device used in the calculation formula (3) of the resin sheet thickness in the method for manufacturing a SAW device of the embodiment of the present invention. ). It is a perspective view (Drawing 7 (a)) and a longitudinal section (Drawing 7 (b)) of a surface mount type SAW device manufactured with a manufacturing method of a SAW device of conventional example 1. It is the longitudinal cross-sectional view (FIG.8 (a)) and horizontal cross-sectional view (FIG.8 (b)) explaining the heat roller lamination process in the manufacturing method of the SAW device of the prior art example 1. FIG. FIG. 9A is a plan view (FIG. 9A) and a longitudinal cross-sectional view (FIG. 9B) illustrating a process of flip-chip mounting a SAW chip on each individual region on a mounting substrate in the SAW device manufacturing method of Conventional Example 2; . It is a longitudinal cross-sectional view of the electronic component (SAW device) manufactured with the manufacturing method of the electronic component (SAW device) of the prior art example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 SAW (surface acoustic wave) device 2 SAW chip 3 Ceramic substrate 4 External electrode 5 Gold bump 6 Resin sealing part (resin sheet)
7 IDT electrode (comb electrode)
10 Lower mold 11 Upper mold 12 Depressurized container 50 Mounting (collection) board S Space

Claims (8)

Flip chip mounting a bumped SAW chip on an aggregate substrate;
A process of heat-softening and pasting a resin sheet having a larger area than the upper surface of the aggregate substrate to the mounted aggregate substrate, leaving a hollow portion, and further resin-sealing by heat curing;
Providing a dicing mark on the back surface of the mounted assembly substrate that has been sealed and cured, and using the dicing mark to cut the assembly substrate into product units,
The thickness t of the resin sheet before the resin sealing step is
t> (i × k × H− (4 ((g−a) / 2 × (j−b) / 2) × 1/3 × d) + ((((g−a) / 2 × b) × 2) × d)
+ ((((J−b) / 2) × a) × 2) × d)) − (a × b × c) + (a × b × d)) / (g × i)
(Where a: the width of the chip (SAW chip)
b: Depth of chip
c: Chip thickness
d: Gap between chip and substrate
e: External shape (width) of product (piezoelectric component)
f: Product outline (depth)
g: Product outline + cutting width (width)
i: Product outline + cutting depth (depth)
j: Product outline-front / back displacement (width)
k: Product outline-front / back displacement (depth)
H: Resin sealing layer thickness)
A method for manufacturing a piezoelectric component, characterized in that The resin sealing step
Placing the assembled substrate mounted on the lower mold; and
Placing a resin sheet having a larger area than the upper surface of the collective substrate on the collective substrate placed; and
A step of degassing and decompressing the inside of the decompression container after disposing the upper mold and the decompression container on the lower mold;
While heating the resin sheet above the softening temperature, pressing and pasting with the upper mold and sealing,
Removing the upper mold and the decompression container from the lower mold after returning the inside of the decompression container to atmospheric pressure;
Removing the sealed aggregate substrate from the lower mold;
The method for manufacturing a piezoelectric component according to claim 1, comprising:   The method of manufacturing a piezoelectric component according to claim 1, wherein the softened resin sheet has a viscosity of 7,000 to 20,000 Pa · s.   2. The method of manufacturing a piezoelectric component according to claim 1, wherein a temperature at which the resin sheet is softened by heating is 30 ° C. to 150 ° C. 3.   The method for manufacturing a piezoelectric component according to claim 1, wherein the resin sheet is made of an epoxy resin.   3. The method for manufacturing a piezoelectric component according to claim 2, wherein the pressure in the decompression vessel at the time of deaeration and decompression is 0.01 to 0.05 atm.   The method for manufacturing a piezoelectric component according to any one of claims 1 to 6, wherein the piezoelectric component is a SAW device.   A piezoelectric component manufactured by the manufacturing method according to claim 1.

Images