Method for manufacturing a packaging unit, packaging unit, electronic module and equipment

Abstract

The present disclosure relates to a method for manufacturing a packaging unit, a packaging unit, an electronic module, and equipment. A method for manufacturing a packaging unit includes: preparing a circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; preparing a mold having a frame-shaped protruding portion surrounding a first cavity, the frame-shaped protruding portion separating the first cavity from the second cavity surrounding the first cavity; arranging the circuit board and the mold so that the first area of ​​the circuit board faces the first cavity, the second area of ​​the circuit board faces the second cavity, and a gap is formed between the frame-shaped protruding portion and the third area of ​​the circuit board so that the first cavity and the second cavity are connected to each other; and forming a frame-shaped resin member on the second area of ​​the circuit board by pouring resin into the second cavity.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a packaging unit, a packaging unit, an electronic module and a device. Background Art

[0002] In recent years, the number of pixels and frame rate of solid-state imaging elements have increased, and further, progress has been made in the digitization of output. Therefore, there is a greater need to increase the transmission speed of the output signal of the solid-state imaging element. To this end, high-speed serial transmission such as LVDS (Low Voltage Differential Signaling) and SLVS (Scalable Low Voltage Signaling) has become common practice.

[0003] Therefore, since the processed signal has a smaller amplitude and a higher rate, the inductance of the wiring of the package (packaging unit), the noise caused by the power-GND loop transmission magnetic field, the crosstalk, etc. are no longer negligible. In addition, since the high-speed transmission signal is transmitted with a small amplitude, the transmission wiring must be an impedance-matched wiring with low power loss. For this reason, efforts are made to shorten the wiring of the output or power supply of the image sensor, reduce impedance mismatch, etc. by directly mounting the image sensing element to the circuit board on which the electronic components are mounted.

[0004] In this context, Japanese Patent Application Laid-Open No. 2015-185763 discloses a technology for forming a frame-shaped mold portion around the periphery of a circuit board and forming a package capable of housing an electronic device. This method enables the generation of dust from the end face of a circuit board to be suppressed by molding the end face of the circuit board with a resin, and can be said to be a promising technology.

[0005] However, in Japanese Patent Application Laid-Open No. 2015-185763, since the circuit board is clamped by the mold when the circuit board is inserted into the mold, problems such as cracks in the circuit board at a portion where the mold and the circuit board surface contact each other and deformation of internal wiring occur.

[0006] WO2009 / 150820 discloses a technique for similarly inserting a circuit board into a mold and performing resin molding, which prevents the circuit board from being damaged by rounding the corners of the mold in the boundary portion of the area where the mold and the circuit board contact each other and providing a board surface with a recess in the boundary portion of the area.

[0007] However, although the method disclosed in WO 2009 / 150820 can reduce damage to the circuit board in the boundary portion of the area where the mold and the circuit board are in contact with each other, there is a problem that the resin material of the circuit board may suffer significant damage. In particular, when there is a variation in the thickness of the circuit board, the pressure applied to the circuit board over the entire contact area between the circuit board and the mold increases, and significant damage occurs in the conductor layer just below the contact area or in the resin material of the circuit board. Summary of the invention

[0008] In view of the above circumstances, an object of the present invention is to provide a highly reliable packaging unit.

[0009] A first aspect of the present disclosure is a method for manufacturing a packaging unit, comprising: preparing a circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; preparing a mold having a frame-shaped protruding portion surrounding a first cavity, the frame-shaped protruding portion separating the first cavity from the second cavity surrounding the first cavity; arranging the circuit board and the mold so that the first area of ​​the circuit board faces the first cavity, the second area of ​​the circuit board faces the second cavity, and a gap is formed between the frame-shaped protruding portion and the third area of ​​the circuit board so that the first cavity and the second cavity are connected to each other; and forming a frame-shaped resin member over the second area of ​​the circuit board by pouring resin into the second cavity.

[0010] A second aspect of the present disclosure is a method for manufacturing a packaging unit, comprising: preparing a circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; preparing a mold having a frame-shaped protruding portion surrounding a first cavity, the first cavity and the second cavity surrounding the first cavity being separated by the frame-shaped protruding portion; arranging the circuit board and the mold so that the first area of ​​the circuit board faces the first cavity, the second area of ​​the circuit board faces the second cavity, and the frame-shaped protruding portion overlaps with the third area of ​​the circuit board; and forming a frame-shaped resin member over the second area of ​​the circuit board by pouring resin into the second cavity, wherein a solder resist layer is arranged in the third area at a position overlapping with the frame-shaped protruding portion, and the solder resist layer of the third area is located between a conductor layer arranged in the first area and a conductor layer arranged in the second area.

[0011] A third aspect of the present disclosure is a packaging unit comprising: a circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; and a resin member covering the circuit board so as to surround a space above the first area of ​​the circuit board, wherein the resin member has (1) a first resin portion arranged above the second area of ​​the circuit board and (2) a second resin portion extending from the first resin portion above the third area of ​​the circuit board and having a thickness less than half of the first resin portion.

[0012] According to the present invention, a highly reliable packaging unit can be provided.

[0013] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figures 1A to 1H-6 is a diagram illustrating a method of manufacturing a packaging unit according to a first embodiment;

[0015] FIG. 2A to FIG. 2C is a diagram illustrating a mold used in a method of manufacturing a packaging unit;

[0016] FIG. 3A to FIG. 3F is a diagram illustrating a method of manufacturing a packaging unit according to a second embodiment;

[0017] Figure 4A to Figure 4G-3 is a diagram illustrating a method of manufacturing a packaging unit according to a second embodiment;

[0018] FIG. 5A to FIG. 5D is a diagram illustrating a method of manufacturing a packaging unit according to a second embodiment;

[0019] FIG. 6A to FIG. 6C is a diagram illustrating a method of manufacturing a packaging unit according to a comparative mode;

[0020] FIG. 7A to FIG. 7C is a diagram illustrating an electronic module using a packaging unit;

[0021] Fig. 8A and Figure 8B is a diagram illustrating a circuit board used in a method of manufacturing a packaging unit; and

[0022] Fig. 9 is a diagram illustrating an example of equipment using an electronic module according to an embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] First embodiment

[0025] A method of manufacturing a packing unit according to a first embodiment of the present invention will be described. Figures 1A to 1G Each step of the method of manufacturing a packaging unit is shown sequentially.

[0026] Figure 1A A cross-sectional view of a stage where the circuit board 1 has been prepared is shown. In this case, it is assumed that the coordinate system is the coordinate system depicted by XYZ in the figure. A plate-like substrate including a wiring conductor can be used as the circuit board 1, and the circuit board 1 is typically a printed circuit board (PCB). Although the circuit board 1 can be a substrate made of an inorganic material, such as a silicon substrate, a ceramic substrate, a glass substrate or a metal substrate, a resin substrate is preferred because copper foil with a low resistivity can be easily used as a circuit conductor. Among the resin substrates, a composite material substrate containing fiber or particle fillers in the resin is particularly preferred, such as a glass-epoxy substrate. Figure 1A is a cross-sectional view in the case where a resin substrate is used as the circuit board 1 .

[0027] Figure 1A-1 1 is an enlarged cross-sectional view of a portion A showing details of a layered structure of a circuit board 1. In this case, an example is shown in which the circuit board 1 is a so-called 2-4-2 build-up substrate having a core layer including four conductor layers 14 and two conductor layers 14 are provided on the front and rear surfaces of the core layer as build-up layers, respectively. The conductor layer 14 is formed of, for example, copper foil. Each conductor layer 14 is patterned into a desired pattern by photolithography.

[0028] The core layer and the buildup layer include a prepreg layer 18. The prepreg layer 18 is configured so that fibers woven or knitted into a fabric pattern are impregnated with resin. As the resin with which the fibers are to be impregnated, a resin having an epoxy resin or phenol as a main component can be widely used, and a resin containing an insulating filler such as paper or glass can also be used. In addition, although glass fiber is generally used as the fiber, the fiber is not limited thereto as long as the fiber has insulating properties.

[0029] In addition, a solder resist layer 11 is provided on the front and rear surfaces of the circuit board 1. As described below, there are mainly two methods for forming the solder resist layer 11. The first method involves pasting a dry film to the front and rear surfaces of the circuit board 1, and performing patterning by photolithography to provide openings at desired positions. The second method involves applying a liquid resist using a roll coater or a spray coater, and performing patterning in a similar manner after curing the liquid resist by UV or heat.

[0030] The front surface electrode 12 is an electrode for connecting wiring from an electronic device. The rear surface electrode 13 is an electrode for connecting electronic components. The front surface electrode 12 is a conductor layer 14 exposed to the front surface, and the rear surface electrode 13 is a conductor layer 14 exposed to the rear surface. The conduction between the front surface electrode 12 and the rear surface electrode 13 is achieved along a desired path via the conductor layer 14, the laser via 16, and the drilled via 15.

[0031] Fig. 8A is a plan view of the front surface of the circuit board 1, and Figure 8B is a plan view of the rear surface of the circuit board 1.

[0032] exist Fig. 8A , the solid line A indicates the position of the end face of the printed circuit board 1. The area surrounded by the dotted line C is the central area (first area) 23. The area between the solid line A and the long dashed line B is the peripheral area (second area) 25. The area between the long dashed line B and the dotted line C, or in other words, the area between the peripheral area 25 and the central area 23, is the middle area (third area) 24. The peripheral area 25 surrounds the central area 23, and the middle area 24 also surrounds the central area 23. On the front surface side of the circuit board 1, a resin frame 41 is provided above the peripheral area 25. On the front surface side of the printed circuit board 1, an electronic device is provided in the central part on the central area 23. Among the central area 23, the area surrounded by the short dashed line D is the mounting area 21 where the electronic device is to be mounted. Among the central area 23, the area (peripheral part) between the dotted line C and the short dashed line D is a connection area 22 for connecting the electronic device to the printed circuit board 1. A plurality of front surface electrodes 12 are arranged in the connection area 22. To ensure that the electronic device can be stored in the packing unit, the thickness (height) of the electronic device is smaller than the thickness wh of the frame-shaped resin portion 40 and larger than the thickness h of the extending resin portion 42 , which will be described later.

[0033] like Figure 8B As shown in FIG. 1 , an electronic component group 2 is provided on the rear surface side of the printed circuit board 1. The electronic components constituting the electronic component group 2 include a connector 221, passive components 222 such as resistors, capacitors, and diodes, active components 223 such as transistors, and an integrated circuit chip 224. Figure 8B In the example shown in , although the electronic component group 2 is provided only in the central area 23 and not in the peripheral area 25 on the rear surface side of the circuit board 1, alternatively, at least a portion of the electronic components of the electronic component group 2 may be arranged in the peripheral area 25.

[0034] Figure 1BThe steps of mounting the electronic component 2 to the rear surface of the circuit board 1 are shown. The electronic component 2 is soldered and connected to the rear surface of the circuit board 1 by a known surface mounting method. Specifically, first, the circuit board 1 is arranged so that the rear surface is the upper surface, and a printing mask having an opening that matches the arrangement of the provided rear surface electrode 13 is prepared. Next, the printing mask is brought into contact with the rear surface so that the opening and the rear surface electrode 13 match each other. In this state, solder paste is arranged on the mask and printed on the rear surface of the circuit board 1 using a scraper.

[0035] Next, using a known mounter, the desired component is mounted to the rear surface of the circuit board 1 so that the rear surface electrode 13 and the terminals of each electronic component match each other. Finally, in this state, the circuit board 1 is passed through a reflow furnace to complete the solder bonding between the rear surface electrode 13 and the terminals of each electronic component.

[0036] When flux contained in the solder paste drops from the circuit board 1 and adheres to the electronic device in the subsequent step, the flux causes a decrease in productivity. Therefore, it is desirable to clean the flux using a known cleaning machine and a known cleaning liquid.

[0037] Preferably, electronic components for surface mounting are mounted. Examples of types of surface mounting electronic components include ceramic capacitors, organic capacitors made of tantalum or the like, chip resistors, B-to-B connectors, regulator ICs for power supplies, common mode connector coils, temperature measurement ICs, and EPROMs.

[0038] Figures 2A to 2C Only the mold 3 used in this embodiment is shown. Figure 1A The mold 3 is composed of an upper mold 31 and a lower mold 32. Figure 2A shows the state where the mold 3 is opened, and Figure 2B The state in which the mold 3 is closed is shown. In the state in which the mold 3 is closed, a cavity is formed inside the mold.

[0039] Figure 2C is a plane view in the Z direction, from Figure 2A The mold 3 is observed in the Z direction of the coordinate system shown in FIG. 1 , and in the figure, the dotted line indicates a boundary line dividing the cavity formed inside the mold 3 into three parts. In this way, the cavity is composed of a central cavity (first cavity) 33, a frame-shaped narrow cavity 34 provided on the periphery of the central cavity 33, and a frame-shaped cavity (second cavity) 35 provided on the periphery of the frame-shaped narrow cavity 34.

[0040] The lower mold 32 has a first bottom surface 32a in the central portion of the region corresponding to the central cavity 33, and a second bottom surface 32b in the region corresponding to the peripheral portion of the central cavity 33, the frame-shaped narrow cavity 34, and the frame-shaped cavity 35. The first bottom surface 32a is positioned lower than the second bottom surface 32b in the Z direction, and can avoid interference with the electronic component 2 when the circuit board 1 is arranged on the second bottom surface 32b. The upper mold 31 has a first top surface 31a in the region corresponding to the central cavity 33, a second top surface 31b in the region corresponding to the frame-shaped cavity 35, and a frame-shaped convex portion 39 between the first top surface 31a and the second top surface 31b. The frame-shaped narrow cavity 34 is formed just below the frame-shaped convex portion 39, and the central cavity 33 and the frame-shaped cavity 35 are partitioned by the frame-shaped convex portion 39. The lower surface of the frame-shaped convex portion 39 is lower in height in the Z direction than the first top surface 31a, and the first top surface 31a is lower in height in the z direction than the second top surface 31b.

[0041] In addition, the mold 3 is provided with a Figure 2B A gate (not shown) for injecting resin in the direction indicated by arrow 201 in FIG. 1 and an air vent (not shown) for releasing air that has been pressed out of the resin in the direction indicated by arrow 202 are provided.

[0042] Figure 1C A state in which the circuit board 1 is inserted into the mold 3 is shown. Figure 1C-1 yes Figure 1C z-direction plane view, and Figure 1C-2 and Figure 1C-3 Each is Figure 1C An enlarged cross-sectional view of portion C1 and portion C2 in FIG.

[0043] like Figure 1C-1 As shown in , in this state, the entire periphery 21 of the circuit board 1 is included in the interior of the frame-shaped cavity 35. In addition, the central area 23 of the circuit board 1 is included in the central cavity 33, the peripheral area 25 is included in the frame-shaped cavity 35, and the middle area 24 is included in the frame-shaped narrow cavity 34 (frame-shaped protruding portion 39). It should be noted that the entire middle area 24 and the frame-shaped protruding portion 39 do not need to be opposite to each other, and the end portion of the middle area 24 on one side of the central area 23 may be included in the central cavity 33. In addition, as Figure 1C-2 and Figure 1C-3As shown in FIG. 3 , a gap 36 is provided between the bottom surface of the frame-shaped protruding portion 39 and the front surface of the circuit board 1. The central cavity 33 and the frame-shaped cavity 35 communicate via the gap 36. In this way, in the first embodiment, in a state where the circuit board 1 is inserted into the mold 3, the circuit board 1 is not clamped by the mold 3. Therefore, damages such as cracks in the circuit board 1 and deformation or breakage of the conductor layer 14, which have been problems in the past, can be prevented from occurring.

[0044] Figure 1D to Figure 1G The process of pouring resin into the frame-shaped cavity 35 through a gate (not shown), filling the frame-shaped cavity 35 with resin 41 while exhausting excess air from a vent (not shown), and maintaining the frame-shaped cavity 35 is shown. Figure 1C The corresponding steps of molding are completed at the same time as the state shown in . Due to these steps, the resin mold covering the outer periphery of the circuit board is molded.

[0045] As the resin 41, a material having the strength and contour stability necessary for the electronic module can be used. In addition, it is desirable that the resin 41 does not contain halogens that adversely affect electronic devices in the use environment of the electronic module and substances that dissolve in moisture over a long period of time and condense and precipitate on the surface of the light-transmitting LID that is the cover of the packaging unit.

[0046] Injection molding can be performed as a molding method. Examples of thermoplastic resins used in injection molding include polyethylene resins, polypropylene resins, ethylene-vinyl acetate, polystyrene, AS resins, ABS resins, acrylic resins, polyvinyl chloride, cellulose resins, polyacetals, polyamides, polyethylene terephthalate, polybutylene terephthalate, polycarbonates, modified polyphenylene ethers, polyphenylene sulfides, polyetheretherketones, liquid crystal polymers, polysulfones, polyethersulfones, polyarylates, polyamide-imides, polyetherimides, and polymethylpentene.

[0047] However, in order to stably maintain strength and shape over a wide temperature range from -40°C to 130°C, thermosetting resins are preferred. Although phenolic resins, urea-formaldehyde resins, melamine resins, diallyl phthalate resins, unsaturated polyester resins, polyimide resins, polyurethane resins, etc. can also be used as thermosetting resins, resins having epoxy resins as main components are preferred. In particular, favorable resins are based on bisphenol A or novolac glycidyl ether type resins, and are compounded with aromatic amine curing agents, phenolic resin curing agents or anhydride curing agents and fillers. As fillers, fillers containing approximately 70 to 85 weight percent of silica powder, talc, etc. are preferred due to the small dimensional variation after molding. In addition, it is also known to include a release agent and a flame retardant for enhancing the demoulding property from the mold 3.

[0048] In the case of the present embodiment, transfer molding capable of keeping the filling pressure of the resin 41 relatively low is more preferred. In the case of transfer molding, a thermosetting resin is used. A resin material having a powdered resin as a main component and including a curing agent, a release agent, a coupling agent, a flame retardant, etc. is preformed into a cylindrical sheet, and the resin sheet is placed in a tank for preheating. In a state where the resin has been melted by preheating and the viscosity has been reduced to within 10 to 100 Pa·s, the resin 41 is squeezed out of the tank using a piston and the resin 41 is injected into the cavity via a cull, a runner, and a gate. It should be noted that, in general, the mold 3 is preheated in advance to a temperature in the range of 100°C to 200°C, which is higher than the glass transition temperature of the resin 41.

[0049] from Figure 1D to Figure 1E , the resin 41 injected from the gate advances to fill the frame-shaped cavity 35. The air in the portion where the resin enters is discharged from the vent (not shown). At this stage, the pressure of the resin 41 is relatively low. Once the pressure reaches Figure 1F At the stage shown in FIG. , the pressure of the resin 41 begins to rise, and finally Figure 1G The filling is completed at a pressure ranging from 5 to 80 MPa in the stages shown in FIG. Figure 1G In the stage shown in FIG. 4 , a portion of the resin 41 penetrates from the frame-shaped cavity 35 into the gap 36 .

[0050] exist Figure 1E-1 The height h of the gap 36 shown in the enlarged cross-sectional view of the portion E in FIG. 1 is defined by the front surface of the circuit board 1 and the top plane of the frame-shaped protruding portion 39, and its value is approximately constant. The height h of the gap 36 is, for example, 0.5 μm or more and 500 μm or less, and is preferably in the range of from 5 to 50 μm. In addition, Figure 1E-1 The width w of the frame-shaped narrow cavity 34 shown in the enlarged cross-sectional view of portion E in FIG. 1 is preferably in the range from 0.1 to 1 mm.

[0051] like Figure 1G-1 As shown in the enlarged cross-sectional view of the portion G1 in FIG. 3 , it is desirable that the resin 41 remain in the gap 36, or in other words, the resin 41 does not advance to the central cavity 33. Under the conditions of the resin viscosity and the gap shape according to the present embodiment, by Figure 1G The pressure of the resin 41 in the stage shown in FIG. 3 is set in the range of 5 to 80 MPa, and the resin 41 can be more or less held in the gap 36. This is because the flow resistance of the gap 36 with respect to the resin 41 is sufficiently high, and therefore, the flow rate of the resin 41 to the gap 36 is sufficiently slowed down, and the curing reaction of the resin 41 can be promoted in a state where the resin 41 remains in the gap 36 to solidify the resin 41. However, as Figure 1G-2As shown in FIG. 3 , the resin 41 may protrude from the gap 36 and may form a terminal resin portion (third resin portion) 44 at the terminal of the extended resin portion 42. The terminal resin portion 44 communicates with the extended resin portion 42 and is located on a side opposite to the frame-shaped resin portion 40 relative to the extended resin portion 42.

[0052] Figure 1H The finished product of the packaging unit according to the first embodiment is shown. Figure 1H-1 is the Z-direction plane view, Figure 1H-2 is an enlarged plan view of section h1, and Figure 1H-3 is an enlarged plan view of portion h2. Figure 1H-4 is an enlarged cross-sectional view of part H1, Figure 1H-5 is an enlarged cross-sectional view of portion H2, and Figure 1H-6 is an enlarged cross-sectional view of portion H3.

[0053] The packaging unit is provided with a circuit board 1 and a resin member 4, which covers the circuit board 1 so as to surround the space above the central area 23 of the circuit board 1. The resin member 4 includes a frame-shaped resin portion 40 (first resin portion) arranged above the conductor layer 14 of the peripheral area 25 of the circuit board 1 and surrounding the outer periphery of the circuit board 1, and an extended resin portion 42 (second resin portion) adjacent to the inner side of the frame-shaped resin portion 40. The extended resin portion 42 extends from the frame-shaped resin portion 40 toward the center of the circuit board 1 above the middle area 24. In addition, since the extended resin portion 42 is molded by the resin that penetrates into the gap 36, its thickness (height) is approximately constant at the height h of the gap 36 and its value is 0.5 μm or more and 500 μm or less, and preferably in the range of from 5 to 50 μm. The thickness of the extended resin portion 42 is, for example, less than half (1 / 2) of the thickness of the frame-shaped resin portion 40, more preferably less than 1 / 4 of the thickness of the frame-shaped resin portion 40, and even more preferably less than 1 / 10 of the thickness of the frame-shaped resin portion 40. Since the contact area between the resin member 4 and the circuit board 1 is increased by providing the extended resin portion 42, the adhesiveness between the resin member 4 and the circuit board 1 is increased. Since the extended resin portion 42 is provided so that the extended resin portion 42 can prevent moisture and the like from penetrating between the frame-shaped resin portion 40 and the circuit board 1, the adhesiveness between the frame-shaped resin portion 40 and the circuit board 1 is increased. By reducing the thickness of the extended resin portion 42, the resin member 4 can be made lightweight, and since the amount of resin 41 used can be reduced, there is also an advantage of reducing costs.

[0054] The thickness h of the extended resin portion 42 may be greater than the thickness t of the uppermost conductor layer 141, so that the height of the upper surface of the extended resin portion 42 is not affected by the thickness of the conductor layer 141 (h>t). The thickness h of the extended resin portion 42 may be twice or more the thickness t of the uppermost conductor layer 141. The height of the upper surface of the extended resin portion 42 from the uppermost conductor layer 141 may be greater than the thickness of the conductor layer 141, and may be twice or more the thickness of the uppermost conductor layer 141. For example, when there is a solder resist layer 11 with a thickness of k below the extended resin portion 42, the height of the upper surface of the extended resin portion 42 from the uppermost conductor layer 141 is h+k, which may satisfy h+k>t or preferably h+k≥2×t. The thickness k of the solder resist layer 11 may be less than at least one of the thickness h and the thickness t. In addition, as shown from Figure 1H-1 to Figure 1H-3 As shown, the outer shape of the inner side of the extended resin portion 42 is an indefinite shape, or in other words, the horizontal length w' is indefinite. However, the maximum value of the horizontal length w' of the extended resin portion 42 is equal to or less than the width w of the gap 36, and is preferably equal to or less than 1 mm. The horizontal length w' can be regarded as the length of a portion of the resin portion that continues at an approximately constant height h in the direction from the peripheral area 25 toward the central area 23. Although in a typical portion of the extended resin portion 42 the horizontal length w' of the portion is greater than the thickness h of the portion (w'>h), the horizontal length w' of another portion of the extended resin portion 42 may be less than the thickness h of the other portion (w'>h). <h)。

[0055] like Figure 1H-2 An enlarged plan view of part h1 and Figure 1H-3 As shown in the enlarged plan view of the portion h2 in FIG. 1 , bubbles 43 are sparsely present inside the extended resin portion 42, but no bubbles are observed inside the frame-shaped resin portion 40. Figure 1GIn the stage shown in , a pressure of 5 to 80 MPa is applied to the resin 41 inside the frame-shaped cavity 35 and the gas contained inside the resin 41 is dissolved into the resin 41, so there are no bubbles inside the frame-shaped resin portion 40. On the other hand, there is a pressure gradient in the resin 41 that has penetrated into the gap 36 of the frame-shaped narrow cavity 34, and the pressure gradient causes the pressure to drop from one side of the frame-shaped cavity 35 toward the side of the central cavity 33. In the resin 41 that has penetrated into the gap 36 of the frame-shaped narrow cavity 34, the portion close to the frame-shaped cavity 35 is subjected to a pressure close to 5 to 80 MPa, and the gas contained inside the resin 41 has more or less dissolved into the resin 41. However, the closer to the central cavity 33, the pressure on the resin 41 drops, and accordingly, the solubility of the gas contained inside the resin 41 decreases, and bubbles 43 are generated. The pressure applied to the resin 41 near the central cavity is almost close to the pressure of the air inside the central cavity 33 and is approximately 1 atmospheric pressure. In this way, since the bubbles are retained in the extended resin portion 42, the surface of the extended resin portion 42 on the side opposite to the surface in contact with the circuit board 1 has holes. Examples of the holes of the extended resin portion 42 include a through-hole that penetrates the extended resin portion 42 and exposes the circuit board 1 constituting the base, and a bottomed hole that is recessed relative to the flat portion of the upper surface of the extended resin portion 42 and the extended resin portion 42 constitutes its bottom, and the through-hole and the bottomed hole may coexist.

[0056] The above-mentioned pressure gradient occurs because the flow resistance with respect to the resin 41 flowing through the gap 36 exists in an appropriate range. Therefore, in order to promote the curing reaction of the resin 41 and solidify the resin 41 in a state where the resin 41 remains in the gap 36, the residual rate of the bubbles of the resin 41 that have penetrated into the gap 36 is preferably higher than the residual rate of the bubbles of the resin 41 existing inside the frame-shaped cavity 35. The preferred range is 30 times or more. In addition, as Figure 1H The residual rate of bubbles contained in the extended resin portion 42 shown in is desirably 30 times or more than the residual rate of bubbles contained in the frame-shaped resin portion 40. In addition, in order to increase the moisture resistance of the packaging unit and maintain the mechanical strength of the packaging unit, it is desirable that the residual rate of bubbles of the frame-shaped resin portion 40 is lower than 5%, more preferably lower than 3%, and even more preferably lower than 1%.

[0057] In this case, the residual rate of bubbles is defined as the area ratio of bubbles in the cross-sectional surface or side surface of the portion where the residual rate of bubbles is to be measured, raised to the power of 3 / 2. In order to measure the residual rate of bubbles in a portion containing a large number of bubbles, the above-mentioned area ratio is defined to be measured relative to the surface where a considerable number of bubbles can be observed.

[0058] Next, further desirable modes of the first embodiment will be described.

[0059] When resin 41 Figure 1G When the front surface electrode 12 is deeply penetrated into the central cavity 33 at the stage shown in FIG. 1 and overlaps the front surface electrode 12, the package is ultimately defective because an electrical connection with the electronic device cannot be formed. Although it is conceivable to avoid such a defect by arranging the front surface electrode 12 and the gap 36 with a large distance between the front surface electrode 12 and the gap 36, this ultimately increases the size of the package and is therefore not preferred.

[0060] With this in mind, Figure 1C-2 An enlarged cross-sectional view of part C1 and Figure 1C-3 As shown in the enlarged cross-sectional view of the portion C2 in FIG. 1 , the height ch of the upper surface 31a of the central cavity 33 from the surface of the circuit board 1 is preferably set to 10 times or more relative to the height h of the gap 36. In addition, the height ch is desirably smaller than the height wh of the upper surface 33b of the frame-shaped cavity 35 from the surface of the circuit board 1 (refer to FIG. Figure 1H ). Thus, even when the resin 41 does not remain in the gap 36 and penetrates into a part of the central cavity 33 and forms the terminal resin portion 44, the possibility of the resin 41 reaching the front surface electrode 12 can be reduced. Therefore, the distance between the front surface electrode 12 and the gap 36 can be kept short, and the effect of preventing the size increase of the packaging unit can be obtained.

[0061] In addition, if Figure 1C-2 An enlarged cross-sectional view of part C1 and Figure 1C-3 As shown in the enlarged cross-sectional view of the portion C2 in FIG. 1 , the recessed portion 17 is preferably formed on the surface of the middle region 24 of the circuit board 1. In a state where the circuit board 1 is mounted inside the mold 3, the recessed portion 17 is formed at a position opposite to the central cavity 33 among the surfaces of the middle region 24 of the circuit board 1, or in other words, at a frame-shaped region adjacent to the frame-shaped protruding portion 39 or the gap 36. The height (Z-direction position) of the front surface of the circuit board 1 in the portion provided with the recessed portion 17 is lower than that in the portion where the recessed portion 17 is not provided. Figure 1C-2 and Figure 1C-3 The recessed portion 17 shown in the figure represents an example in which the recessed portion 17 is formed by an opening provided in the solder resist layer 11. By providing the above-mentioned recessed portion 17, even if Figure 1G As shown in FIG. 4 , when the resin 41 penetrates into the central cavity 33 and forms the terminal resin portion 44, the resin 41 is also pooled in the recessed portion 17, and the possibility of the resin 41 reaching the front surface electrode 12 can be reduced. Therefore, the distance between the front surface electrode 12 and the gap 36 can be kept short, and the effect of preventing the size increase of the packaging unit can be obtained.

[0062] The distance between the recessed portion 17 and the gap 36 is preferably in the range of from 0.05 to 1 mm. When the distance is shorter than this range, the deviation of the position of the circuit board 1 inside the cavity of the mold 3 causes the recessed portion 17 and the gap 36 to interfere with each other, and makes it difficult to properly maintain the height h of the gap 36. In addition, when the distance is too long, the size of the packaging unit increases. In order to suppress the positional deviation of the circuit board 1 inside the cavity of the mold 3, a circular hole and a U-shaped hole can be opened on the circuit board 1, and a pin (protrusion) that fits into the circular hole and the U-shaped hole can be provided on the mold 3.

[0063] In addition, the distance between the recessed portion 17 and the front surface electrode 12 is also preferably in the range of from 0.05 to 1 mm. When the distance is shorter than this range, depending on the processing accuracy of the recessed portion 17, the recessed portion 17 and the front surface electrode 12 interfere with each other and make it difficult to properly maintain the length of the front surface electrode 12. For example, when the recessed portion 17 is a groove provided on the solder resist layer 11 by photolithography, the positioning accuracy of the mask when performing photolithography is the processing accuracy of the recessed portion 17. In addition, when the distance between the recessed portion 17 and the front surface electrode 12 is longer than 1 mm, the size of the packaging unit increases.

[0064] It is also preferable to set the distance between the recessed portion 17 and the front surface electrode 12 to be shorter than the distance between the recessed portion 17 and the gap 36. The distance between the recessed portion 17 and the gap 36 can be regarded as the distance between the recessed portion 17 and the extended resin portion 42, as is the distance between the terminal resin portion 44 and the extended resin portion 42. Adoption of such a configuration makes it possible to retain the resin 41 in the recessed portion 17 and reduce the possibility that the resin 41 reaches the front surface electrode, while suppressing an increase in the size of the packaging unit.

[0065] Furthermore, the width of the recessed portion 17 is preferably in the range from 0.1 to 1 mm. When the width is shorter than 0.1 mm, the space for accumulating the resin 41 becomes insufficient. When the width is longer than 1 mm, the size of the packaging unit increases.

[0066] In addition, Figure 1H-5The height th of the terminal resin portion 44 from the front surface of the circuit board 1 shown in the enlarged cross-sectional view of the portion H2 in FIG. 1 is preferably greater than the height h of the extended resin portion 42 from the circuit board 1. In other words, the thickness of the terminal resin portion 44 is preferably greater than the thickness of the extended resin portion 42. In addition, preferably, the lower end position of the terminal resin portion 44 is lower than the lower end position of the extended resin portion 42, and the upper end position of the terminal resin portion 44 is higher than the upper end position of the extended resin portion 42. Adoption of such a configuration makes it possible to set the height th of the terminal resin portion 44 to be greater than the height h of the extended resin portion 42. The higher the height th of the terminal resin portion 44, the lower the height h of the extended resin portion 42. Figure 1G-2 As shown in the enlarged cross-sectional view of the portion G2 shown in FIG. 3 , the amount of the resin 41 accumulated in the recessed portion 17 is also larger when the resin 41 permeates into the central cavity 33. This is preferable because the possibility that the resin 41 reaches the front surface electrode 12 can be reduced.

[0067] However, from the perspective of the packaging unit, the height th of the terminal resin portion 44 is higher than Figure 1H The case where the height wh of the frame-shaped resin portion 40 shown in FIG. is not preferred. In order to prevent this from happening, Figure 1C-2 and Figure 1C-3 The height ch of the central cavity 33 shown in FIG. 3 from the front surface of the circuit board 1 is preferably lower than the height wh of the frame-shaped cavity 35 from the front surface of the circuit board 1. In other words, the thickness of the terminal resin portion 44 is preferably smaller than the thickness of the frame-shaped resin portion 40.

[0068] In addition, fillers may be added to the resin 41 as described above, and the fillers preferably include particles having a particle size greater than Figure 1C-2 An enlarged cross-sectional view of part C1 and Figure 1C-3 The filler is preferably a silica filler. In addition, the volume content of the silica filler is preferably 80% or more. This is because, by Figure 1G By filling the gap 36 with silica filler in the stage shown in FIG, the amount of resin 41 that penetrates into the central cavity 33 can be reduced because the fluidity of the resin 41 in the gap 36 decreases. Since the height h of the gap 36 is equal to the thickness of the extended resin portion 42, the frame-shaped resin portion 40 has a filler whose particle size is larger than the thickness of the extended resin portion 42.

[0069] Second embodiment

[0070] A method of manufacturing a packing unit according to a second embodiment of the present invention will be described. FIG. 3A to FIG. 3F An example of a method of manufacturing a packaging unit according to the second embodiment is shown. Figure 3AThe first embodiment shown in FIG. Figure 1C 1 and 2. The diagram corresponds to a stage of the present invention and shows a state in which the circuit board 1 has been inserted into the mold 3. The mold 3 is the same as that of the first embodiment.

[0071] Figure 3B is a Z-direction plane view (cross-section view) of the packaging unit, and FIG. 3C to FIG. 3F They are enlarged cross-sectional views of portions A1 to A4 , respectively.

[0072] The circuit board 1 is the same as the circuit board of the first embodiment except that the total thickness of the circuit board 1 is 10% thicker than that of the circuit board of the first embodiment. FIG. 3C to FIG. 3F As shown in the enlarged cross-sectional views of portions A1 to A4 shown in FIG. 1 , the circuit board 1 has a plurality of conductor layers 14 .

[0073] The upper mold 31 of the mold 3 has a frame-shaped protruding portion 39 in a portion between the central cavity 33 and the frame-shaped cavity 35. The top frame-shaped plane 37 ( Figure 3C and Figure 3D ) and the relative plane 38 of the lower mold 32 ( Figure 3E and Figure 3F ) clamps the circuit board 1, and the relative plane 38 is provided to be opposite to the top frame-shaped plane 37.

[0074] FIG. 4A to FIG. 4D The production stages of the circuit board 1 according to the second embodiment are shown. Figure 4A-1 An enlarged view of a cross section taken at portion D2 in a Z-direction plan view shown in . The circuit board 1 shown in the figure is a so-called 2-4-2 build-up substrate, and step a represents a stage where two build-up layers have been formed on both surfaces of a core layer, respectively.

[0075] Figure 4B FIG. 1 shows a stage of step b. In step b, the uppermost conductor layer 141 formed in step a is patterned by photolithography. The uppermost conductor layer 141 is formed in Figure 3A The conductor layer 14 closest to the top frame-shaped plane 37 in the state where the circuit board 1 is inserted into the mold 3 is shown in FIG.

[0076] Figure 4B-1 1 is a plan view of the circuit board 1 viewed from the z direction in the stage of step b. As shown, the conductor layer 141 is provided with a frame-shaped opening 1411 in the portion sandwiched between the two rectangular dotted lines. The area provided with the frame-shaped opening 1411 can be provided in a subsequent step in an area including a position overlapping with the frame-shaped protruding portion 39, and can be provided, for example, in the entire middle area 24 ( Fig. 8A )middle. Figure 4BA frame-shaped opening 1411 is also shown. The frame-shaped opening 1411 is a portion in which at least the uppermost conductor layer 141 has been removed in a frame shape by photolithography. The frame-shaped opening 1411 can also be described as a frame-shaped recessed portion. Figure 4B and Figure 3D As is clear from the comparison between the two, a frame-shaped opening 1411 is provided in a portion where the top frame-shaped plane 37 of the mold 3 and the conductor layer 141 are opposite to each other. The frame-shaped opening 1411 is provided in this portion and has a width kw greater than a width w of the top frame-shaped plane 37.

[0077] Figure 4C The stage of step c is shown. In step c, the solder resist layer 11 is formed on the front surface of the circuit board 1. The solder resist layer 11 is formed by applying a liquid resist using a known roller coater, a spin coater, a spray coater, etc. and solidifying the liquid resist by applying heat or UV. In the case of a liquid solder resist, even if the thickness of the portion where the conductor layer 141 exists and the thickness of the portion where the conductor layer 141 does not exist (the frame-shaped opening 1411) are the same at the time point of applying the liquid resist, the thickness of the solder resist layer 11 after solidification is different. Specifically, the thickness tk of the opening portion where the conductor layer 141 does not exist becomes 10 to 30% thicker than the thickness td of the portion where the conductor layer 141 exists. This is because, even when the thickness is the same at the time point of applying the liquid resist, the liquid resist flows from the portion where the conductor layer 141 exists to the portion where the conductor layer 141 does not exist (the opening) before solidification and a leveling effect occurs, in which the liquid surface becomes flat by itself.

[0078] Figure 4D FIG. 2 shows a stage of step d. In step d, exposure and development processing are performed on the cured solder resist layer 11 to open an opening in a desired portion of the circuit board 1. Figure 4D As shown in , the solder resist layer 11 remains in at least a portion of the frame-shaped opening 1411. As described later, the solder resist layer 11 is preferably formed in a portion sandwiched by the frame-shaped protruding portion 39 of the mold 3. In addition, as Figure 4D As shown in FIG. 1 , the solder resist layer 11 is formed to remain also in a portion other than the frame-shaped opening 1411 (except the frame-shaped recessed portion) in the front surface of the circuit board 1 .

[0079] Figure 4E is a diagram showing a state in which the circuit board 1 is inserted into the mold 3 and is sandwiched by the top frame-shaped plane 37 and the opposite plane 38, and is Figure 3DSame figure. In the circuit board 1, the central area 23 is opposite to the central cavity 33, the peripheral area 25 is opposite to the frame-shaped cavity 35, and the frame-shaped narrow cavity 34 (frame-shaped protrusion 39) is opposite to the middle area 24. The frame-shaped protrusion 39 contacts (overlaps) the solder resist layer 11 in the middle area 24 of the circuit board 1. The solder resist layer 11 overlapping with the frame-shaped protrusion 39 is the solder resist layer provided in the frame-shaped opening 1411, or in other words, the solder resist layer located between the conductor layer 14 of the central area 23 and the conductor layer 14 of the peripheral area 25.

[0080] At this stage, the frame-shaped protrusion 39 bites into the solder resist 11 and causes the solder resist 11 to deform and dent. In other words, the surface of the solder resist 11 in the middle area 24 (the surface on the side opposite to the circuit board 1) is a dented surface. In addition, a slight dent also occurs in the prepreg layer 18 in the portion indicated by the arrow 22. However, the degree of the dent can be maintained within the range where the strength of the package does not become insufficient or the moisture resistance of the package does not decrease. This is because the thickness of the resist layer 11 formed in the frame-shaped opening 1411 as the contact area with the frame-shaped protrusion 39 is set to be 10 to 30% thicker than the portion covering the conductor layer 14. The resist layer 11 effectively absorbs the stress applied from the frame-shaped protrusion 39 and deforms, and prevents damage to the prepreg layer 18 and the conductor layer 14.

[0081] Figure 4F A stage is shown at which the resin 41 has flowed into a part of the cavity of the mold 3 , or in other words, into the frame-shaped cavity 35 .

[0082] Figure 4G is an overall completed view of a package according to a second embodiment. Figure 4G-1 is its Z-direction plane view, and Figure 4G-2 and Figure 4G-3 They are Figure 4G-1 An enlarged cross-sectional view of portion G1 and portion G2 in FIG.

[0083] The complete package is composed of a circuit board 1 including a plurality of conductor layers 14 and a frame-shaped resin portion 40 provided to surround the periphery of the circuit board 1. The uppermost conductor layer 141 among the plurality of conductor layers 14 is removed along the entire inner periphery of the frame-shaped resin portion 40 to form a frame-shaped opening (frame-shaped recessed portion) 1411. In addition, at least a portion of the entire frame-shaped opening 1411 and the uppermost conductor layer 141 is covered with a solder resist 11 produced by curing the liquid resist. As previously mentioned, the central portion of the frame-shaped opening 1411 is clamped by the frame-shaped protruding portion 39 of the mold 3. By being clamped, the solder resist 11 is deformed, and the thickness of the solder resist 11a in the portion (central portion of the frame-shaped opening 1411) clamped by the frame-shaped protruding portion 39 becomes thinner than the thickness of the solder resist 11b in the peripheral portion. A slight depression also occurs in the prepreg layer 18 in the portion indicated by the arrow 22. However, the degree of the depression can be kept within a range in which the strength of the package does not become insufficient or the moisture resistance of the package does not decrease.

[0084] Use of a solder resist having a low elastic modulus is also effective in preventing the occurrence of depressions in the prepreg layer 18. In particular, a solder resist having an elastic modulus of about 2-4 GPa is preferred. An example of a liquid resist having relatively low elasticity is PSR-4000AUS308 manufactured by TAIYO INK MFG Co., Ltd.

[0085] FIG. 5A to FIG. 5D is a diagram showing a preferred example of the second embodiment. FIG. 5A to FIG. 5D yes Figure 5A-1 The enlarged cross-sectional view of the portion B2 in the Z-direction plane view in FIG. FIG. 4A to FIG. 4G The differences in the examples shown in .

[0086] The processing until step d is similar to the above processing. Figure 4D ) Figure 5A In the step shown in , the solder resist layer 19 is formed again on the circuit board 1 .

[0087] Next, if Figure 5B As shown in FIG. 1 , the solder resist layer 19 is patterned by photolithography, and a solder resist layer 191 is formed on the frame-shaped opening 1411 produced in the uppermost conductor layer 141. In this way, two solder resist layers 11 and 191 are formed in the frame-shaped opening 1411.

[0088] Next, if Figure 5CAs shown in FIG. 1 , the circuit board 1 is inserted into a mold whose central cavity 33 has a height dh different from that of the central cavity of the mold 3 according to the first embodiment. The height dh of the central cavity 33 can be regarded as the length of the frame-shaped protruding portion 39. In this embodiment, the height dh of the central cavity 33 can be set to be greater than Figure 1C-3 The height ch shown in FIG. is shorter by 20 to 30 μm. Thus, the following effect is produced: although the solder resist layer 11 and the solder resist layer 191 are deformed, the solder resist layer 11 and the solder resist layer 191 effectively absorb the stress applied from the frame-shaped protrusion 39 and prevent damage to the portion indicated by the arrow 22 of the prepreg layer 18 and to the conductor layer 14. Finally, as Figure 5D As shown in FIG. 4 , the resin 41 is poured into a part of the cavity of the mold 3 , or in other words, into the frame-shaped cavity 35 to mold the terminal resin portion 44 .

[0089] <Comparison Mode>

[0090] Next, we will refer to FIG. 6A to FIG. 6C Describes the comparison modes. These are shown in Figure 6A-1 An enlarged view of a cross section taken at portion A2 in the Z-direction plan view shown in FIG.

[0091] In the present comparative mode, instead of providing the frame-shaped opening 1411 on the uppermost conductor layer 141 of the circuit board 1 according to the second embodiment, the molding process is performed by sandwiching the circuit board 1 with the mold 3 . Fig. 6A shows that the opening is not provided in the Figure 4B In the step shown in FIG. 1 , a portion of the frame-shaped opening 1411 is provided. Figure 6B In this case, the solder resist layer 11 is formed. Figure 4C Differently, since there is no frame-shaped opening 1411, the leveling effect of the liquid solder resist is not produced, and the solder resist layer 11 has a uniform thickness td.

[0092] also, Figure 6C The state in which the circuit board 1 is inserted into the same mold 3 as the first embodiment is shown. As shown, in this example, since the thickness of the solder resist layer 11 is insufficient and the frame-shaped opening 1411 does not exist on the uppermost conductor layer 141 so that the stress applied from the frame-shaped protruding portion 39 reaches the lower part of the circuit board 1, cracks 181 may occur in the prepreg layer 18. In addition, cracks 142 may also occur in the uppermost conductor layer 141, and therefore it is not preferable.

[0093] Third embodiment

[0094] Reference FIG. 7A to FIG. 7CAn electronic module using a packaging unit according to the first embodiment or the second embodiment is described. The electronic module is configured to include an electronic device mounted on a circuit board of a package and a cover portion covering the package. When the electronic device is an imaging device, the electronic module is an imaging module, and when the electronic device is a display device, the electronic module is a display module. In order to ensure that the electronic device can be stored in the packaging unit, the thickness (height) of the electronic device is less than the thickness wh of the frame-shaped resin portion 40 and greater than the thickness h of the extended resin portion 42. By reducing the thickness of the extended resin portion 42, the side surface of the resin member 4 facing the space surrounded by the resin member 4 (the inner surface of the frame-shaped resin portion 40) can be separated from the electronic device 5. When the electronic device is a display device or an imaging device, since the reflection of light by the side surface of the resin member 4 can be suppressed, the image quality degradation caused by the reflected light can be suppressed. By making the thickness of the extended resin portion 42 less than the thickness of the electronic device, the optical effect of the extended resin portion 42 on the surface (upper surface) of the electronic device on the side opposite to the circuit board 1 can be reduced as much as possible.

[0095] The method of manufacturing the electronic module is as follows. First, Fig. 7A As shown in , the packaging unit 100 is fixed to a known suction table 7, and an electronic device 5 such as an imaging device is bonded and fixed to the central portion of the packaging unit 100 via a known adhesive 6. By reducing the thickness of the extended resin portion 42, the volume of the space surrounded by the resin member 4 can be increased. Thus, since the working space can be expanded when the electronic device 5 is arranged in the space surrounded by the resin member 4, the electronic device 5 can be easily arranged. Next, as Figure 7B As shown in the figure, the electrode pads of the electronic device 5 and the front surface electrodes 12 of the packaging unit 100 are connected to each other using a known wire bonding method using a known wire 8. The side surface of the resin member 4 (the inner surface of the frame-shaped resin portion 40) can be separated from the electronic device 5. Thus, the resin member 4 can be prevented from interfering with the capillary when performing wire bonding. Finally, the known light-transmitting cover 10 is bonded and fixed to the packaging unit 100 via a known adhesive to complete the imaging element module. The distance between the light-transmitting cover 10 and the electronic device 5 can be controlled by the thickness of the frame-shaped resin portion 40. At this time, by sufficiently reducing the thickness of the extended resin portion 42, the extended resin portion 42 is prevented from unnecessarily affecting the distance between the light-transmitting cover 10 and the electronic device 5.

[0096] This electronic module can be applied to various equipment. Although applicable equipment is not particularly limited, examples thereof include electronic information equipment (electronic equipment, information equipment) such as smart phones, cameras and personal computers. Alternatively, examples of equipment to which the present invention can be applied include communication equipment for performing radio communications, office equipment such as copiers and scanners, and transportation equipment such as automobiles, ships and aircraft. Alternatively, examples of equipment to which the present invention can be applied include industrial equipment such as robots, analysis equipment using energy beams (light, electron beams or radio waves), and medical equipment such as endoscopes and radiation equipment. In the equipment to which the present invention is applied, the circuit board of the electronic module according to the above-mentioned embodiment is connected to the other parts of the equipment. Although the functions of the other parts of the equipment to which the circuit board is to be connected can be appropriately set depending on the function of the electronic module, examples of these parts include parts for controlling or driving the electronic module and parts for processing signals for communicating with the electronic module. It is advantageous to adopt the electronic module according to the present embodiment in the equipment in terms of improving the durability and reliability of the equipment and the miniaturization and lightweight of the equipment. Examples of equipment to be installed with an imaging module include various equipment such as digital still cameras, digital video cameras, surveillance cameras, copiers, fax machines, mobile phones, vehicle-mounted cameras, observation satellites, and cameras for medical use. Such equipment includes an optical system, electronic equipment, and a processing device. The electronic equipment as the imaging equipment performs photoelectric conversion on a subject image formed by the optical system, and outputs the photoelectrically converted subject image as an image signal or a focus detection signal. The processing device performs image processing, equipment control processing, etc. based on the signal output from the imaging equipment. Examples of equipment control include control of a moving body such as a vehicle, a ship, or an aircraft.

[0097] Fig. 9A camera CMR is illustrated as an example of equipment to which an electronic module is applied. The camera CMR may include an imaging module IS, an electrical module MB, and a display module DP. The electrical module MB is a component for controlling the imaging module IS and / or the display module DP or supplying power to the imaging module IS and / or the display module DP and a component for processing signals for communicating with the imaging module IS and / or the display module DP. The electrical module MB may be connected to a circuit board of the electronic module via a flexible wiring. In the camera CMR, the display module DP may constitute an electronic viewfinder (EVF) or may constitute a touch panel. In addition, the camera CMR may include a lens LNS that is attachable to and detachable from a camera body or a lens LNS that is fixed to the camera body. The camera CMR may include a machine module MCHN for moving the imaging module IS inside the camera body. Any one of the electronic modules according to the above-mentioned embodiments may be any one of the imaging module IS and the display module DP. The imaging module IS is connected to the electrical module MB via a flexible printed wiring board FPC1 connected to the imaging module IS. The display module DP is connected to the electrical module MB via a flexible printed wiring board FPC2 connected to the display module DP. The flexible printed wiring board may be connected to Fig. 8A and Figure 8B The connector 221 shown in FIG. In the camera CMR, the camera anti-shake (anti-vibration) function can be realized by moving (shifting) the imaging module IS corresponding to the electronic module by the machine module MCHN. Since the imaging module IS to which the electronic module according to the present embodiment is applied is lightweight, the moving speed of the imaging module IS can be increased and the load on the machine module MCHN for movement can be reduced. Since the electronic module according to the present embodiment has a highly reliable packaging unit, the durability of the equipment involving such movement of the electronic module can be increased.

[0098] First example

[0099] Hereinafter, examples of the present invention will be described. Figure 2A The mold 3 shown in FIG. Figures 1A to 1H The packaging unit 100 is manufactured by the method of manufacturing a packaging unit shown in FIG.

[0100] A resin substrate was used as the circuit board 1 and was configured as a so-called 2-4-2 build-up substrate. The conductor layer 14 was produced using a 18 μm thick copper foil.

[0101] The core layer and the buildup layer include a prepreg layer 18. The prepreg layer 18 is configured such that fibers woven or knitted into a fabric pattern are impregnated with resin. Epoxy resin containing an insulating filler is used as the resin.

[0102] Furthermore, the front and rear surfaces of the circuit board 1 are provided with solder resist layers 11. The solder resist layers 11 are formed by a method involving applying a liquid resist using a roll coater, curing the liquid resist by UV and heat, and then performing patterning in a similar manner.

[0103] The electronic component 2 is soldered and connected to the surface of the Figure 1B The rear surface of the circuit board 1 shown in FIG. The flux cleaning is performed using a known cleaning machine and a known cleaning liquid.

[0104] The electronic components used include ceramic capacitors, organic capacitors made of tantalum and the like, chip resistors, B-to-B connectors, regulator ICs for power supplies, common mode connector coils, temperature measurement ICs, and EPROMs.

[0105] FIG. 2A to FIG. 2C Only the mold 3 used in this example is illustrated. The mold 3 is composed of an upper mold 31 and a lower mold 32 . Figure 2A shows the state where the mold 3 is opened, and Figure 2B FIG. 2 shows a state where the mold 3 is closed. When the mold 3 is closed, a cavity is prepared inside the mold. Figure 2B As shown in FIG. 1 , the cavity is composed of a central cavity 33, a frame-shaped narrow cavity 34 provided on the periphery of the central cavity 33, and a frame-shaped cavity 35 provided on the periphery of the frame-shaped narrow cavity 34. In addition, the mold 3 is provided with a Figure 2B A gate (not shown) for injecting resin in the direction indicated by arrow 201 in FIG. 1 and a vent (not shown) for releasing air that has been pressed out of the resin in the direction indicated by arrow 202 .

[0106] Figure 1C FIG. 2 shows a state in which the circuit board 1 according to this example is inserted into the mold 3. Figure 1C-1 As shown in the Z-direction plan view of FIG. 3 , in this state, the entire periphery 21 of the circuit board 1 is included inside the frame-shaped cavity 35. In addition, a gap 36 is provided between the inner surface of the frame-shaped narrow cavity 34 and the front surface of the circuit board 1. In this way, in the present example, in the state where the circuit board 1 is inserted into the mold 3, the circuit board 1 is not clamped by the mold 3. Therefore, the occurrence of damages such as cracks in the circuit board 1 and deformation or breakage of the conductor layer 14, which have been problems in the past, can be prevented.

[0107] Transfer molding is used in this example. A thermosetting resin is used. A resin material having a powdered resin as a main component and including a curing agent, a release agent, a coupling agent, and a flame retardant is formed into a cylindrical sheet, and the resin sheet is placed in a tank for preheating. In a state where the resin has been melted by preheating and the viscosity has been reduced to 30 Pa·s, the resin 41 is squeezed out of the tank using a piston and the resin 41 is injected into the cavity via a rejector, a runner, and a gate. The mold 3 is preheated in advance to a temperature of 145°C, which is higher than the glass transition temperature of the resin 41 of 140°C.

[0108] from Figure 1D to Figure 1E , the conditions are selected so that the resin 41 injected from the gate advances to fill the frame-shaped cavity 35. The air in the portion where the resin enters is adjusted to be discharged from the vent (not shown). At this stage, the pressure of the resin 41 is relatively low, at 4 MPa. Once it reaches Figure 1F At the stage shown in FIG. 1 , the pressure of the resin 41 begins to rise, and finally reaches a pressure of 30 MPa. Figure 1G The filling is completed in the stages shown in .

[0109] Figure 1E-1 The height h of the gap 36 shown in the enlarged cross-sectional view of the portion E in FIG. 1 is adjusted to 30 μm. In addition, Figure 1E-1 The width w of the frame-shaped narrow cavity 34 shown in the enlarged cross-sectional view of the portion E in FIG. 1 is similarly set to 0.3 mm. By adopting such a condition, in the case of Figure 1G In the final stage shown in FIG. 1 , when the viscosity of the resin 41 is 30 Pa·s as described above, it is possible to more or less hold the resin 41 in the gap 36, as shown in FIG. Figure 1G-1 This is because the flow resistance of the gap 36 with respect to the resin 41 is sufficiently high, and therefore the flow rate of the resin 41 to the gap 36 is sufficiently slowed down, and it is possible to advance the curing reaction of the resin 41 while the resin 41 remains in the gap 36 to solidify the resin 41.

[0110] Figure 1H denoted a finished product of the packaging unit according to this example. The finished product is provided with a circuit board 1, a frame-shaped resin portion 40 surrounding the outer periphery of the circuit board 1, and an extended resin portion 42 adjacent to the inner side of the frame-shaped resin portion 40. Figure 1H-1 to Figure 1H-3 As shown in FIG. 4 , the outer shape of the inner side of the extended resin portion 42 is an indefinite shape. Figure 1H-4 to Figure 1H-6 The height h of the narrow resin mold portion shown in the enlarged cross-sectional view in FIG. Figure 1E-1 The height h of the gap 36 shown in the enlarged cross-sectional view of the portion E shown in corresponds to and has a value of 30 μm.

[0111] like Figure 1H-2 and Figure 1H-3 As shown in the enlarged plan view in FIG. 4 , bubbles 43 are sparsely present inside the extended resin portion 42, but no bubbles are observed inside the frame-shaped resin portion 40. The reason why bubbles are not present inside the frame-shaped resin portion 40 is that Figure 1G In the stage shown in , a pressure of 30 MPa is applied to the resin 41 inside the frame-shaped cavity 35 and the gas contained inside the resin 41 is dissolved in the resin 41. On the other hand, there is a pressure gradient in the resin 41 that has penetrated into the gap 36 of the frame-shaped narrow cavity 34, which causes the pressure to drop from one side of the frame-shaped cavity 35 toward the side of the central cavity 33. In the resin 41 that has penetrated into the gap 36 of the frame-shaped narrow cavity 34, the portion close to the frame-shaped cavity 35 is subjected to a pressure close to 30 MPa, and the gas contained inside the resin 41 has more or less dissolved in the resin 41. However, the closer to the central cavity, the pressure on the resin 41 drops, and therefore, the solubility of the gas contained inside the resin 41 decreases, and bubbles 43 are generated. The pressure applied to the resin 41 near the central cavity is almost close to the pressure of the air inside the central cavity 33 and is approximately 1 atmospheric pressure.

[0112] The above-mentioned pressure gradient occurs because the flow resistance with respect to the resin 41 flowing through the gap 36 exists within an appropriate range. Comparison between the residual rate of bubbles of the resin 41 that has penetrated into the gap 36 and the residual rate of bubbles of the resin 41 existing inside the frame-shaped cavity 35 yields a result of 55 times. Thus, it is possible to advance the curing reaction of the resin 41 in a state where the resin 41 remains in the gap 36 to solidify the resin 41. In addition, compared with the residual rate of bubbles contained in the frame-shaped resin portion 40, as shown in FIG. Figure 1H The residual rate of bubbles contained in the extended resin portion 42 shown in FIG is also 60 times or more. In addition, the residual rate of bubbles contained in the frame-shaped resin portion 40 is 0.1%, and therefore it is possible to sufficiently increase the moisture resistance of the package and maintain the mechanical strength of the package.

[0113] The effect of the present invention is clearly seen from this example.

[0114] Second example

[0115] A package manufacturing method according to a second example will be described.

[0116] As circuit board 1 , circuit board 1 having a total thickness 10% thicker than that of the first example was used.

[0117] The difference from the first example is that the circuit board 1 is sandwiched by a top frame-shaped flat surface 37 of a frame-shaped protruding portion 39 of the mold 3 and an opposing flat surface 38 provided to be opposed to the top frame-shaped flat surface 37 .

[0118] FIG. 4A to FIG. 4D The production stages of the circuit board 1 according to the present example are shown. Figure 4A-1 An enlarged view of a cross section taken at portion D2 in the Z-direction plan view shown in FIG.

[0119] Figure 4B FIG. 2 shows step b, or in other words, shows a stage in which the uppermost conductor layer 141 formed in step a is patterned by photolithography. The conductor layer 141 is formed when the circuit board 1 is inserted into the Figure 3A The conductor layer 14 is closest to the top frame-shaped plane 37 in the state inside the mold 3 shown in FIG.

[0120] Figure 4B-1 is a plan view of the circuit board 1 viewed from the z direction at the stage of step b. As shown, the conductor layer 141 is provided with a frame-shaped opening 1411 in a portion sandwiched between two rectangular dotted lines. Figure 4B Also shown is a frame-shaped opening 1411. Figure 4B and Figure 3D As can be clearly seen from the comparison between the two, the frame-shaped opening 1411 is a portion where the top frame-shaped plane 37 of the mold 3 and the conductor layer 141 are opposite to each other. The frame-shaped opening 1411 is provided in this portion and its width kw is greater than the width w of the top frame-shaped plane 37. The width kw is set to 0.62 mm and the width w is set to 0.3 mm.

[0121] Figure 4C is a diagram showing step c, or in other words, a diagram showing a stage in which a solder resist layer 11 is formed. The solder resist layer 11 is formed by applying a liquid resist using a known roller coater and solidifying the liquid resist by applying heat or UV. In the stage of applying the liquid resist, the portion of the conductor layer 141 where the pattern is present and the frame-shaped opening 1411 where the pattern is not present have the same thickness of 30 μm. However, after curing, the thickness tk of the opening portion where the pattern is not present is 35 μm and the thickness td of the portion where the pattern is present is 28 μm, indicating a 25% increase in thickness. This is because, before the liquid resist solidifies, the liquid resist flows from the portion where the pattern is present into the portion where the pattern is not present and a leveling effect occurs, in which the liquid surface flattens itself.

[0122] Figure 4D Step d is shown, or in other words, a stage in which exposure and development processes are performed on the cured resist layer 11 and an opening is opened in a desired portion of the circuit board 1 to complete the circuit board 1 is shown.

[0123] Figure 4E is a diagram showing a state in which the circuit board 1 is inserted into the mold 3 and is sandwiched by the top frame-shaped plane 37 and the opposite plane 38, and is Figure 3DSame figure. At this stage, the frame-shaped protrusion 39 has bitten into the solder resist layer 11 and caused the solder resist layer 11 to deform. In addition, although a slight depression also appeared in the prepreg layer 18 in the portion indicated by the arrow 22, the strength of the package did not become insufficient and the moisture resistance of the package did not decrease. This is because the thickness of the resist layer 11 formed in the frame-shaped opening 1411 which is the contact area with the frame-shaped protrusion 39 is set to be 25% thicker than other parts. When the total thickness of the circuit board 1 becomes 10% thicker, the resist layer 11 effectively absorbs the stress applied from the frame-shaped protrusion 39 and deforms, and prevents damage to the prepreg layer 18 and the conductor layer 14.

[0124] Figure 4F There is shown a stage in which the resin 41 has flowed into the frame-shaped cavity 35 which is a part of the cavity of the mold 3. A solder resist having a low elastic modulus is used. Specifically, a solder resist having an elastic modulus of 3.4 GPa is used.

[0125] The effect of the present invention is clearly seen from this example.

[0126] Other embodiments

[0127] The (one or more) embodiments of the present invention may also be implemented by a computer of a system or device that reads and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more completely referred to as a "non-transitory computer-readable storage medium") to perform one or more functions of the above (one or more) embodiments and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing one or more functions of the above (one or more) embodiments, and by a method executed by a computer of a system or device by, for example, reading and executing computer executable instructions from a storage medium to perform one or more functions of the above (one or more) embodiments and / or controlling one or more circuits to perform one or more functions of the above (one or more) embodiments. The computer may include one or more processors (e.g., a central processing unit (CPU), a microprocessing unit (MPU)), and a network that may include separate processors or separate computers to read and execute computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or a storage medium. The storage medium may include, for example, a hard disk, a random access memory (RAM), a read-only memory (ROM), a storage device of a distributed computing system, an optical disk (such as a compact disk (CD), a digital versatile disk (DVD), or a Blu-ray disk (BD)) TM ), one or more of flash memory devices, memory cards, etc.

[0128] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A method for manufacturing a packaging unit, characterized in that: include: preparing a circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; preparing a mold having a frame-shaped protruding portion surrounding a first cavity, the frame-shaped protruding portion separating the first cavity from a second cavity surrounding the first cavity; Arranging the circuit board and the mold so that the first area of ​​the circuit board faces the first cavity, the second area of ​​the circuit board faces the second cavity, and a gap is formed between the frame-shaped protruding portion and the third area of ​​the circuit board so that the first cavity and the second cavity communicate with each other; forming a frame-shaped resin member over the second area of ​​the circuit board by pouring resin into the second cavity; as well as forming a cover fixed to the resin member, wherein, after the cover is formed, a space is provided between the cover and the circuit board in a region inside the frame-shaped resin member. 2 . The method of manufacturing a packaging unit according to claim 1 , wherein forming the frame-shaped resin member includes pouring the resin so that a part of the resin permeates from the second cavity into the gap.

3. The method for manufacturing a packaging unit according to claim 1, wherein The circuit board has a recessed portion at a position corresponding to the first cavity, and Forming the frame-shaped resin member includes pouring the resin so that a portion of the resin permeates into the first cavity and also accumulates in the recessed portion.

4. The method for manufacturing a packaging unit according to claim 1, wherein a solder resist layer is arranged in the third region at a position overlapping with the frame-shaped protruding portion, and the solder resist layer in the third region is located between the conductor layer arranged in the first region and the conductor layer arranged in the second region. 5 . The method of manufacturing a packaging unit according to claim 4 , wherein a thickness of the solder resist layer in the third region is greater than a thickness of the solder resist layer covering the conductor layer.

6. A packaging unit, characterized in that: include: A circuit board having a first area, a second area surrounding the first area, and a third area between the first area and the second area; a resin member covering the circuit board so as to surround a space above the first area of ​​the circuit board, and a cover fixed to the resin member, wherein the resin member has (1) a first resin portion disposed above the second region of the circuit board and (2) a second resin portion extending from the first resin portion above the third region of the circuit board and having a thickness less than half of the first resin portion, The space is a region surrounded by the resin member and is located between the cover and the circuit board. 7 . The packing unit according to claim 6 , wherein the second resin portion has a portion in which a length of the second resin portion in a direction from the second region toward the first region is larger than a thickness of the second resin portion. 8 . The packaging unit according to claim 6 , wherein the first resin portion contains a filler having a particle size larger than a thickness of the second resin portion.

9. The packaging unit according to claim 6, wherein the thickness of the second resin portion is in the range between 5 and 50 μm, and wherein a length of the second resin portion in a direction from the second region toward the first region is 1 mm or less. 10 . The packing unit according to claim 6 , wherein the second resin portion has a hole on a side of the second resin portion opposite to a circuit board side.

11. The packing unit according to claim 6, wherein the resin member includes a third resin portion continuous with the second resin portion on a side opposite to the first resin portion relative to the second resin portion, and a thickness of the third resin portion is greater than a thickness of the second resin portion but less than a thickness of the first resin portion.

12. The packaging unit according to claim 11, wherein the lower end position of the third resin portion is lower than the lower end position of the second resin portion, and The upper end position of the third resin portion is higher than the upper end position of the second resin portion.

13. The packaging unit according to claim 6, wherein a recessed portion is provided on a surface of the third region of the circuit board, wherein a third resin portion continuous with the second resin portion is provided on a side opposite to the first resin portion with respect to the second resin portion, and The third resin portion is located inside the recessed portion. 14 . The packing unit according to claim 13 , wherein a distance between the recessed portion and an electrode provided on the front surface of the circuit board is shorter than a distance between the recessed portion and the first resin portion. 15 . The packing unit according to claim 13 , wherein a distance between the recessed portion and an electrode provided on the surface of the circuit board is in a range between 0.05 and 1 mm, and a width of the recessed portion is in a range between 0.1 and 1 mm.

16. The packing unit according to any one of claims 6 to 15, wherein the resin member covers an end surface of the circuit board.

17. An electronic module, characterized in that: include: The packaging unit according to any one of claims 6 to 16; as well as an electronic device, the electronic device being arranged on the first area of ​​the circuit board, The thickness of the electronic device is smaller than the thickness of the first resin portion and larger than the thickness of the second resin portion.

18. An electronic module, characterized in that: include: A packaging unit according to any one of claims 6 to 16, and an electronic device, the electronic device being arranged on the first area of ​​the circuit board, wherein the electronic device is an imaging device or a display device, and A plurality of passive components are arranged on a side of the circuit board opposite to the electronic device side.

19. An apparatus, characterized in that: include: The electronic module according to claim 17 or 18; as well as An electrical module is connected to the circuit board via a flexible wiring.

20. An apparatus, characterized in that: include: The electronic module according to claim 17 or 18; as well as A machine module moves the electronic module.

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