JP4778370B2 - Manufacturing method of electronic parts - Google Patents

Description

The present invention relates to a method for manufacturing an electronic component in which an active element of a chip is not directly covered with a resin or the like.

In recent years, the recording density of optical discs has improved, and the wavelength of laser light used for reading information on optical discs has become shorter. In the optical pickup semiconductor device that detects laser light, the light detection portion is covered with resin, and the resin is more likely to deteriorate as the wavelength of the laser light becomes shorter. Therefore, conventionally, a photodetection semiconductor device in which the photodetection portion is exposed without being covered with resin is known (Patent Document 1).
JP 2003-273371 A

  In the photodetection semiconductor device of Patent Document 1, when the photodetection unit is packaged with resin, the resin is cured before the resin covers the photodetection unit, or the resin covering the photodetection unit is sucked before curing. Suction with a jig or the like, or troublesome work was inevitable.

(1) The invention according to the method for manufacturing an electronic component according to claim 1 is an electronic component manufacturing method in which a chip having an active element is resin-sealed, and an external electrode provided on a flexible substrate. The chip is mounted so that the active element surface faces the flexible substrate at a predetermined distance, and the flexible substrate is attached to the vacuum printing machine so that the chip and the external electrode enter the opening of the stencil plate. Resin is supplied to the upper surface facing the active element surface of the chip and the peripheral side surface of the chip and screen-printed in a reduced-pressure atmosphere compared to atmospheric pressure, and a gas reservoir is formed between the flexible substrate and the active element Thus, the chip is resin-sealed on a flexible substrate, and the active substrate is exposed by peeling the flexible substrate.
(2) The invention of claim 2 is characterized in that, in the method of manufacturing an electronic component according to claim 1, the size of the gas reservoir is controlled by changing the atmospheric pressure at the time of resin sealing.
(3) According to a third aspect of the present invention, there is provided an electronic component manufacturing method in which a chip having an active element is resin-sealed, and an external electrode provided on a flexible substrate is provided. The chip is mounted so that the active element surface faces the flexible substrate at a predetermined distance, and a gas reservoir is formed between the flexible substrate and the active element in a reduced pressure atmosphere compared to atmospheric pressure. The chip is resin-sealed on a flexible substrate, the flexible substrate is peeled off to expose the active element, and the opening formed by the gas reservoir is closed with a glass plate or a hard plastic plate It shall be the.

  According to the present invention, the chip is resin-sealed so that the atmospheric gas is accumulated in the active element of the chip. Therefore, an electronic component in which the active element of the chip is not directly covered with resin or the like can be easily manufactured.

  A photodetection semiconductor device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1A is a back view of the photodetection semiconductor device 1, and FIG. 1B is a cross-sectional view taken along line A-A 'of FIG.

  In FIG. 1, reference numeral 1 denotes a photodetection semiconductor device, and 2 denotes a photodetection semiconductor element. The light detection semiconductor element 2 is provided with a light detection unit 2A. The light detection semiconductor device 1 has an opening (hereinafter referred to as a light receiving opening 1A), and the light detection portion 2A of the light detection semiconductor element 2 is exposed on the bottom surface of the light receiving opening 1A. Then, light such as laser light entering the light receiving opening 1A is received and detected by the light detection unit 2A. An external electrode 3 is disposed on the light receiving opening 1A side of the photodetection semiconductor device 1, and the photodetection semiconductor element 2 and the external electrode 3 are connected by a bump 5 made of Au or the like. Reinforcing pads 4 are provided at the four corners of the photodetection semiconductor device 1 in order to increase the adhesive strength with the circuit board. The photodetection semiconductor element 2, the external electrode 3, and the reinforcing pad 4 are sealed with a resin 6, for example, an epoxy resin. The surrounding surface 1B of the resin 6 surrounding the periphery of the light detection unit 2A in the light receiving opening 1A is concave.

  As described above, the light detection unit 2A of the light detection semiconductor element 2 is exposed on the back surface of the light detection semiconductor device 1, and the light incident on the light receiving opening 1A is directly received by the light detection unit 2A. . The external electrode 3 and the reinforcing pad 4 are also exposed on the back surface of the optical semiconductor device 1 and can be mounted on the circuit board by soldering.

  The layer structure of the external electrode 3 and the reinforcing pad 4 will be described with reference to FIG. The external electrode 3 and the reinforcing pad 4 are composed of a Ni layer 21 mainly formed by electroforming. The thickness of the Ni layer 21 is, for example, 30 to 60 μm. Above and below the Ni layer 21 are Au layers 23 for connecting the external electrodes 3 and the bumps 5 through Pd layers 22 and 24, which are intermediate layers, and for improving the solder wettability of the external electrodes 3. , 25 are provided.

  Next, a method for manufacturing the above-described photodetection semiconductor device 1 will be described with reference to FIGS. FIG. 3 is a flowchart for explaining a manufacturing method of the photodetection semiconductor device 1. As shown in FIG. 3, a photodetection semiconductor device 1 is produced by mounting a photodetection semiconductor element 2 produced by dividing a wafer into a metal plate on which an electrode is formed and sealing with a resin.

  A wafer used for manufacturing the photodetection semiconductor device 1 has a plurality of photodetection portions 2A as active elements. Further, as the metal plate, a thin metal plate having flexibility such as a flat JIS standard SUS stainless steel plate or Cu plate having a thickness of about 0.1 mm is used.

  In step 301, a predetermined number of bumps 5 are formed on each element on the wafer. The bumps 5 are attached to the wafer by ultrasonic bonding described later. In step 302, the wafer is diced into individual pieces, and the light detection semiconductor element 2 is manufactured.

In step 303, the external electrode 3 is formed on the metal plate by electroforming. The external electrode forming step of the metal plate in step 303 will be described with reference to FIG. As shown in FIG. 4A, a resist 42 is applied or laminated on both surfaces of the metal plate 41. Next, an acrylic film-based pattern mask film is brought into intimate contact and exposed to ultraviolet rays. Then, development is performed, and as shown in FIG. 4B, a portion of the resist 42 where the external electrode 3 is to be formed is removed. Since no electrode is formed on one surface of the metal plate 41, the entire surface remains covered with the resist 42. Next, the surface of the metal plate 41 where the resist 42 has been removed is soft etched with an oxidizing solution such as H ₂ SO ₄ —H ₂ O ₂ or Na ₂ S ₂ O ₈ . And it pickles with acids, such as a sulfuric acid, and performs an acid activation process.

The external electrode 3 is formed on the metal plate 41 that has been subjected to the acid activation treatment. The external electrode 3 is formed as follows.
(1) The metal plate 41 is immersed in an Au plating solution, and the Au layer 25 is formed on the metal substrate 41 by plating.
(2) It is immersed in a Pd plating solution, and a Pd layer 24 is formed on the Au layer 25 by plating.
(3) The Ni layer 21 is formed on the Pd layer 24 by dipping in a Ni plating solution and supplying power to the metal plate 41 to perform electroforming.
(4) The metal plate 41 is immersed in a Pd plating solution, and the Pd layer 22 is formed on the Ni layer 21 by plating.
(5) The metal plate 41 is immersed in the Au plating solution, and the Au layer 23 is formed on the Pd layer 22 by plating.

  As described above, the external electrode 3 having the layer structure shown in FIG. 2 is formed on the metal plate 41 as shown in FIG. Then, the resist 42 is peeled off from the metal plate 41 as shown in FIG. The reinforcing pad 4 is also formed on the metal plate 41 simultaneously with the external electrode 3.

  In step 304 of FIG. 3, the metal plate 41 on which the external electrode 3 is formed is plasma cleaned. By this plasma cleaning, Au on the surface of the external electrode is activated, and the connection strength between the external electrode 3 and the bump 5 provided on the photodetection semiconductor element 2 can be increased.

  In step 305, the photodetection semiconductor element 2 is flip-chip connected to the metal plate 41 by ultrasonic bonding. The flip chip connecting process will be described with reference to FIG. The photodetection semiconductor element 2 is mounted on the metal plate 41 so that the bumps 5 are arranged on the external electrode 3, and a bonding tool 51 is applied to the photodetection semiconductor element 2. Then, ultrasonic vibration is applied to the light detection semiconductor element 2 while being pressed by the bonding tool 51. As a result, the bump 5 and the external electrode 3 are connected, and the photodetecting semiconductor element 2 is mounted on the metal plate 41.

  In step 306, the photodetection semiconductor element 2, the external electrode 3, and the reinforcing pad 4 mounted on the metal plate 41 are sealed with resin by a vacuum printing machine. Here, the vacuum printer is a device that screen-prints a sealing resin in a vacuum atmosphere and seals a semiconductor element or the like. The resin sealing process by a vacuum printer will be described with reference to FIG.

  A metal plate 41 on which the photodetection semiconductor element 2 is mounted is attached to a vacuum printing machine, and the stencil plate so that the photodetection semiconductor element 2 and the external electrode 3 enter the opening 61A of the stencil 61 as shown in FIG. Align 61. Next, the inside of the vacuum printing machine is depressurized to, for example, 30000 Pa, and the squeegee 62 is moved to print the sealing resin 63 on the metal plate 41 as shown in FIG. The sealing resin 63 is made of, for example, a thermosetting epoxy resin. At this time, an atmospheric gas remains in the vicinity of the center of the photodetection semiconductor element between the photodetection semiconductor element 2 and the metal plate 41, and a gas pool 64 is generated. Due to the gas reservoir 64, the periphery of the light detection unit 2A is not filled with the sealing resin, and the light detection unit 2A is not covered with the sealing resin 63.

  Next, the pressure in the vacuum printing machine is raised to atmospheric pressure, for example. As a result, the pressure around the gas reservoir increases and the gas reservoir 64 decreases as shown in FIG. For this reason, the sealing resin 63 filling the opening 61A of the stencil 61 is apparently reduced. Therefore, in order to fill the opening 61A of the stencil 61 again with the sealing resin 63, the squeegee 62 is moved as shown in FIG. 6D, and the sealing resin 63 is printed again. Then, the stencil 61 is removed, and the resin sealing step is completed as shown in FIG.

  In step 307 of FIG. 3, the resin-sealed metal plate 41 is placed in an oven and heated at a predetermined temperature, for example, 100 ° C. to cure the sealing resin 63. At this time, since the gas in the gas reservoir 64 expands, the gas reservoir 64 becomes larger. In step 308, the metal plate 41 is peeled off from the resin-encapsulated photodetection semiconductor element 2 or the like. Since the metal plate 41 has flexibility, it can be easily peeled off as shown in FIG. When the metal plate 41 is peeled off, the light detection portion 2A of the light detection semiconductor element 2 is exposed in the light receiving opening 1A. Moreover, since the light receiving opening 1A is formed by the gas reservoir 64, the surrounding surface 1B of the resin 6 surrounding the periphery of the light detection portion 2A has a concave shape. Hereinafter, what peeled off the metal plate 41 shown in FIG.7 (b) is called the resin sealing body 70. FIG.

  In step 309, as shown in FIG. 8A, the resin sealing body 70 is diced along the one-dot chain line 81 by the diamond blade dicing method. Then, as shown in FIG. 8B, one resin sealing body 70 is divided, and the photodetection semiconductor device 1 is completed.

  The photodetection semiconductor device 1 manufactured as described above is mounted via a solder 92 on a circuit board 91 provided with a hole 91A as shown in FIG. In this case, the laser beam LB irradiated for reading information on the optical disk is reflected by the optical disk surface, passes through the hole 91A of the circuit board 91, and enters the light receiving opening 1A of the light detection semiconductor device 1. The laser beam LB incident on the light receiving opening 1A does not pass through the resin 6 and directly enters the light detection portion 2A of the light detection semiconductor element 2. For this reason, the resin that covers the light detection unit 2A by the laser light LB is not deteriorated, and the light detection semiconductor device is not disabled.

The manufacturing method of the photodetection semiconductor device 1 according to the above embodiment has the following effects.
(1) Resin sealing was performed under reduced pressure, and the light detection semiconductor element 2 was sealed with the resin 6 so that the ambient gas was collected around the light detection portion 2A. Therefore, the photodetection semiconductor device 1 in which no resin exists in the optical path to the photodetection unit 2A can be easily manufactured.

(2) Since there is nothing in contact with the photodetection part 2A of the photodetection semiconductor element 2 throughout the entire process, the photodetection part 2A is not damaged. That is, as described above, in the conventional example, a step of bringing the suction jig closer to the light receiving surface of the light detection unit 2A and sucking the resin before curing is also necessary. In the present embodiment, such a suction jig or the like is unnecessary, and there is no possibility of damaging the light detection unit 2A.

(3) The size of the gas reservoir 64 generated when the resin is sealed can be controlled by the degree of pressure reduction when the resin is sealed. That is, when the degree of decompression is increased, the gas reservoir 64 is reduced, and when the pressure is reduced to a vacuum, the gas reservoir 64 is hardly generated. On the other hand, if the degree of decompression is reduced, the gas reservoir 64 becomes larger. Thus, in the embodiment of the present invention, the size of the light receiving opening 1A can be easily controlled by adjusting the pressure at the time of resin sealing. An example is shown in FIG. FIG. 10A shows the shape of the light receiving opening 1A obtained when the atmospheric pressure during resin printing in FIG. 6B is 30000 Pa. 10B shows the shape of the light receiving opening 1A when the pressure is controlled to 20000 Pa, FIG. 10C to 10000 Pa, and FIG. 10D to 5000 Pa, respectively. For example, by setting the pressure at the time of printing to 10000 Pa, as shown in FIG. 10C, the photodetecting portion 2A is not covered with the resin, and the photodetecting semiconductor element 2 is covered with the resin 6 as much as possible. A light receiving opening 1A having a size can be obtained.

(4) Since the photodetection semiconductor element 2 is resin-sealed by a screen printing method using a vacuum printer, the pressure at the time of resin sealing can be easily controlled, and the size of the light receiving opening 1A is controlled. can do.

(5) Since the surrounding surface 1B of the resin 6 surrounding the light detection unit 2A is concave, the laser beam reflected from the surrounding surface 1B does not enter the light detection unit 2A. Therefore, erroneous detection due to the laser beam reflected on the surrounding surface 1B can be prevented.

The photodetection semiconductor device 1 of the above embodiment can be modified as follows.
(1) The present invention is not limited to resin sealing by a vacuum printing machine as long as the resin can be sealed by changing the pressure of the atmosphere at the time of resin sealing of the photodetecting semiconductor element 2.

(2) When the light detection unit 2A is not at the center of the light detection semiconductor element 2 in plan view, the position of the gas reservoir 64 can be adjusted as follows according to the arrangement of the light detection unit 2A. For example, the shape of the squeegee 62 is changed so that the amount of the sealing resin 63 flowing between the light detection semiconductor element 2 and the metal plate 41 is different between the right and left sides of the light detection semiconductor element 2, and the gas pool The position of 64 may be controlled. Alternatively, an inflow blocking portion that makes it difficult for the sealing resin 63 to flow between the light detection semiconductor element 2 and the metal plate 41 is formed on the metal plate 41 or the like to control the flow of the sealing resin 63. Thus, the position of the gas reservoir 64 may be controlled.

(3) Although the semiconductor device 1 for photodetection has been described, the present invention is not limited to the semiconductor device 1 for photodetection as long as the active element of the chip is an electronic component that is not directly covered with resin or the like. For example, you may apply to various sensors, such as a SAW filter and a pressure sensor.

(4) Although the external electrode 3 is mainly composed of the Ni layer 21 by electroforming, it is not limited to Ni as long as it is a metal having conductivity. For example, you may comprise with the Cu layer by electroforming.

(5) Although the Au layer 25 is provided for connecting the external electrode 3 and the solder, the Au layer 25 is not limited to the Au layer 25 as long as it is a metal layer for connecting to the solder. For example, a Sn layer, a Sn—Pb layer, a Sn—Ag layer, a Sn—Cu layer, a Sn—Bi layer, or the like may be formed.

(6) The substrate on which the external electrodes 3 and the like are formed is not limited to the metal plate 41 as long as it is a flexible plate-like flexible substrate. For example, a conductive resin substrate may be used. Moreover, when forming the external electrode 3 using electroless plating, it does not need to be a conductive substrate like the metal plate 41, and may be a non-conductive substrate.

(7) An external electrode is formed on a flexible sheet, the chip is mounted on the external electrode formed on the sheet, the external electrode and the chip are electrically connected, and the resin is sealed, and then the sheet If it is an electronic component which peels and divides | segments and produces, it will not be limited to embodiment of this invention. For example, the present invention may be applied to a QFN (Quad Flat Non-Leaded Package) produced by a MAP (Molded Array Packaging) method. In this case, the external electrode formed on the sheet becomes a lead frame instead of electroformed Ni. Further, the sheet is an assembly sheet which is a resin sheet having adhesiveness instead of the metal plate 41 having flexibility.

(8) In a line in which a plurality of types of electronic components are mixed, the process can be automated as follows. For example, the atmospheric pressure at the time of sealing resin printing is stored for each electronic component, and the image of the chip set on the printing machine or the pattern of the external electrode 3 formed on the metal plate 41 is recognized. Read the type. Then, the optimum atmospheric pressure for the read electronic component may be read and the pressure during printing may be adjusted. Such a printing machine includes a storage device that stores a table that stores the atmospheric pressure during printing of the sealing resin 63, a chip set in the printing machine, a pattern of the external electrode 3 formed on the metal plate 41, and the like. An image recognition device that reads the type of electronic component that will be produced by recognizing the image, and a control device that controls the atmospheric pressure during printing by collating a table stored in the storage device based on the type of electronic component read It can be prepared. By using such a printing machine, the atmospheric pressure at which the active element is optimally exposed is automatically set for each type of electronic component, and the convenience for the user is improved.

(9) In order to prevent dust or the like from adhering to the light detection portion 2A of the light detection semiconductor element 2, or to prevent a decrease in the reliability of the light detection semiconductor element 2 due to the humidity of the outside air, The light receiving opening 1A may be closed with glass or hard plastic. A photodetection semiconductor device 100 in which the light receiving opening 1A is covered with a glass plate 7 will be described with reference to FIG. Portions common to the photodetection semiconductor device 1 of the embodiment of the present invention are denoted by the same reference numerals, and portions different from the photodetection semiconductor device 1 of the embodiment of the present invention are mainly described. FIG. 11A is a back view of the photodetection semiconductor device 100, and FIG. 11B is a cross-sectional view taken along line B-B ′ of FIG.

  As shown in FIG. 11, the light receiving opening 1A of the photodetection semiconductor device 100 is closed by a glass plate 7, and the glass plate 7 is fixed by an adhesive 8 made of a thermosetting resin such as an epoxy resin.

  Next, a method for manufacturing the photodetection semiconductor device 100 will be described with reference to FIGS. FIG. 12 is a flowchart for explaining a manufacturing method of the photodetection semiconductor device 100.

  The process proceeds to step 308 in the same process as that of the photodetection semiconductor device 1 in the embodiment of the present invention. In step 401, as shown in FIG. 13A, a paste-like adhesive is formed around the light receiving opening 1A in the resin sealing body 70. Agent 8 is applied. Application of the adhesive 8 is performed, for example, by printing or ejection from a nozzle. In step 402, as shown in FIG. 13B, the separated glass plate 7 is placed on the adhesive 8 so as to cover the light receiving opening 1A. At this time, the glass plate 7 is pressed so that the applied adhesive 8 spreads. In step 403, the resin sealing body 70 is put in an oven and heated at a predetermined temperature to cure the adhesive 8. In step 309, as shown in FIG. 13C, the resin sealing body 70 is diced by the diamond blade dicing method along the alternate long and short dash line 82 as in the case of the photodetection semiconductor device 100. As a result, as shown in FIG. 13D, one resin sealing body 70 is divided, and the photodetection semiconductor device 100 is completed.

  The photodetection semiconductor device 100 manufactured as described above is mounted with a solder 92 on a circuit board 93 provided with a hole 93A of a size into which the glass plate 7 as shown in FIG. In this case, the laser beam LB irradiated for reading the information on the optical disc is reflected by the optical disc surface, and the reflected laser beam LB passes through the glass plate 7 and enters the light detection portion 2A of the light detection semiconductor element 2. To do.

  Here, although the thermosetting resin is used for the adhesive 8 of the photodetection semiconductor device 100, an ultraviolet curable resin may be used. In this case, in step 403, the resin sealing body 70 is irradiated with ultraviolet rays instead of being heated. Moreover, although the paste-like thing was used for the adhesive agent 8, you may make it provide the adhesive agent 8 around 1 A of light receiving openings by sticking a sheet | seat using a sheet-like thing.

  In step 401, the adhesive 8 is applied to the resin sealing body 70, but instead of applying the adhesive 8 to the resin sealing body 70, the adhesive 8 may be applied to the glass plate 7.

  The glass plate 7 is not limited as long as it transmits the laser beam LB, and for example, a hard plastic plate may be used.

  The present invention is not limited to the embodiment described above as long as it has the characteristic configuration.

FIG. 1A is a back view of the photodetection semiconductor device according to the embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line A-A ′ of FIG. It is a figure for demonstrating the layer structure of an external electrode and a reinforcement pad. It is a flowchart for demonstrating the manufacturing method of a photon detection semiconductor device. It is a figure for demonstrating the process of forming an external electrode by the electroforming method on a metal plate. It is a figure for demonstrating the flip chip connection process of a photon detection semiconductor element. It is a figure for demonstrating the resin sealing process using a vacuum printer. It is a figure for demonstrating the peeling process of a metal plate. It is a figure for demonstrating the dicing process of a resin sealing body. It is a figure for demonstrating the photon detection semiconductor device mounted in the circuit board. It is a figure for demonstrating the magnitude | size of the light-receiving opening when the pressure of the atmosphere at the time of resin sealing is changed. FIG. 11A is a rear view of the photodetection semiconductor device in which a glass plate is provided in the light receiving opening, and FIG. 11B is a cross-sectional view taken along the line B-B ′ of FIG. It is a flowchart for demonstrating the manufacturing method of the photon detection semiconductor device which provided the glass plate in the light-receiving opening. It is a figure for demonstrating the process of providing a glass plate in a light-receiving opening. It is a figure for demonstrating the photon detection semiconductor device which provided the glass plate in the light-receiving opening mounted in the circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Photodetection semiconductor device 1A Light reception opening 1B Surrounding surface 2 Photodetection semiconductor element 2A Photodetection part 3 External electrode 4 Reinforcement pad 5 Bump 6 Resin 7 Glass plate 8 Adhesive 41 Metal plate 42 Resist 51 Bonding tool 61 Stencil 61A Opening Section 62 Squeegee 63 Sealing resin 64 Gas reservoir 70 Resin sealing bodies 91, 93 Circuit board 92 Solder

Claims (3)

In a manufacturing method of an electronic component formed by resin-sealing a chip having an active element,
A chip is mounted on an external electrode provided on a flexible substrate so that the active element surface faces the flexible substrate with a predetermined distance therebetween,
Attaching the flexible substrate to a vacuum printing machine so that the chip and the external electrode enter the opening of the stencil,
Resin is supplied to the upper surface of the chip facing the active element surface and the peripheral side surface of the chip and screen-printed in a reduced-pressure atmosphere as compared to the atmospheric pressure, and between the flexible substrate and the active element. The chip is resin-sealed on the flexible substrate so that a gas reservoir is formed,
A method of manufacturing an electronic component, wherein the active element is exposed by peeling the flexible substrate. In the manufacturing method of the electronic component of Claim 1,
A method of manufacturing an electronic component, wherein the size of the gas reservoir is controlled by changing an atmospheric pressure when the resin is sealed. In a manufacturing method of an electronic component formed by resin-sealing a chip having an active element,
A chip is mounted on an external electrode provided on a flexible substrate so that the active element surface faces the flexible substrate with a predetermined distance therebetween,
Resin-sealing the chip on the flexible substrate so that a gas reservoir is formed between the flexible substrate and the active element under a reduced pressure atmosphere compared to atmospheric pressure,
Peeling the flexible substrate to expose the active element;
A method of manufacturing an electronic component, wherein an opening formed by the gas reservoir is closed with a glass plate or a hard plastic plate.

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