JP2001148506A - Infrared data communication module and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a molding die in adhesion to a board, so as to prevent resin from spreading to the rear of the board when a resin package is formed on the surface of the board using the molding die. SOLUTION: An infrared data communication module is manufactured through such a method, in which a chip area 19 including a wiring pattern 70 is provided on a surface 10a of a board 1, a through-hole is previously provided in the chip area 19, and a resin package is formed on the surface 10a of the board 1 by the use of a resin molding die, when a light emitting element and a photodetector mounted in the chip areas 19 are sealed up with the resin. Before the resin package is formed on the surface 10a of the board 1, a dummy area 21 including a dummy pattern 22, that corresponds to the wiring patter 70 as a whole, is formed as large in area as the chip area 19 ion the rear surface 10b at a position and counterposes it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a so-called IrD
The present invention relates to an infrared data communication module used for performing infrared data communication according to the A (Infrared Data Association) standard.

[0002]

2. Description of the Related Art IrDA-compliant infrared data communication modules have become very popular in the field of notebook personal computers, and have recently become widespread in mobile phones and electronic organizers. This kind of infrared data communication module is
Infrared LEDs, photodiodes, modulation / demodulation circuits, and the like are integrated into a single package to enable bidirectional wireless communication. Communication speeds, communication distances, and the like are defined as uniform standards by version. As the performance of infrared data communication functions has been enhanced, the size of the entire module has become smaller and smaller due to downsizing.In the manufacturing process, strict dimensional accuracy is required and cost reduction is called for. I have.

[0003] Therefore, the inventor of the present invention, who has been diligently researching and developing in this kind of field, has completed a new excellent method as a method of manufacturing an infrared data communication module, and has described the manufacturing method in another application. Already disclosed by. The outline of the manufacturing method will be described. First, in a first step, a chip area for partitioning and mounting a set of an infrared LED and a photodiode for each set is provided on a surface of a substrate in a state of being regularly arranged. This chip area is a fixed area having a wiring pattern formed of pads and electrodes for infrared LEDs and photodiodes in the area, and a through hole penetrating in the thickness direction of the substrate near an area boundary. Refers to the area of the section. Subsequently, in a second step, an infrared LED, a photodiode, and the like are mounted so as to be connected to the wiring pattern in the chip area. Next, in a third step, a resin package is formed on a surface of the substrate by using a resin molding die as a device for sealing an infrared LED, a photodiode, and the like mounted on each chip area. At this time, the infrared L
Two or more sets of the ED and the photodiode are collectively sealed by one resin package common to each other. Finally, the resin package and the substrate are cut so that the two sets of the infrared LED and the photodiode are separated into each set, and further, a shielding part is provided to provide infrared data composed of one set of the infrared LED and the photodiode. A single communication module can be obtained. According to the above-described manufacturing method, the production efficiency can be increased and the production cost can be reduced by forming two sets of the infrared LED and the photodiode into one package in the production process.

[0004]

Here, when the resin package is formed in the third step, a surface mold in a shape corresponding to the shape of the resin package is pressed against the surface of the substrate. Since there is no need to form a resin package on the back surface of the substrate, a back mold having a flat pressing surface is pressed against the back surface. In other words, on the front surface side of the substrate, the resin filled between the front surface mold and the substrate is solidified to form a resin package, while on the back surface side of the substrate, the back surface mold is provided. Is in a state of being in close contact with the entire rear surface of the substrate.

However, on the back surface of the substrate, only a terminal connected to the opening of the through hole is formed, and since this terminal has a thickness even though it is an extremely thin conductor,
Since a slight undulation occurs on the back surface of the substrate, there is a problem in the adhesion of the back surface mold to the substrate. In short, when the adhesion between the backside mold and the substrate is poor, the surface pressure near the through hole on the backside of the substrate becomes insufficient, and there is a possibility that a gap may be generated between the backside substrate and the mold. When resin is filled between the front mold and the substrate in a state where there is such a fear, the resin that should be on the front surface of the substrate goes around the back surface of the substrate through through holes, and Unnecessary resin may adhere to the back surface side.

Accordingly, the present invention was conceived under the circumstances described above, and when forming a resin package on the surface of a substrate using a mold, the adhesion of the mold to the substrate is improved. It is an object of the present invention to provide a method of manufacturing an infrared data communication module and a method of manufacturing an infrared data communication module that can sufficiently prevent the resin from sneaking into the back surface of the substrate through the through hole.

[0007]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

In other words, the method for manufacturing an infrared data communication module provided by the first aspect of the present invention provides a chip for mounting a set of light-emitting elements and light-receiving elements on a surface of a substrate by partitioning each set. Areas are provided and through holes are provided in these chip areas in the thickness direction of the substrate, and when the light emitting element and the light receiving element mounted on each of the chip areas are sealed, A method for manufacturing an infrared data communication module, wherein a resin package is formed using a resin molding die on the surface, wherein the chip is formed on the back surface of the substrate before the resin package is formed on the surface of the substrate. At each location opposite to the area, a dummy area of the same size as the chip area is formed.

According to the method for manufacturing an infrared data communication module provided by the first aspect of the present invention in which the above technical means are employed, the substrate is provided with a chip area on the surface of the substrate on which the resin package is to be formed. A dummy area is provided on the back surface of the same size as the above-mentioned chip area at a location opposite to the chip area, and when a resin package is formed using a mold, portions provided as a chip area and a dummy area of the substrate are provided. It is thicker than the other parts and is strongly pressed by the mold. Therefore, the surface pressure applied by the mold is sufficient in the portion where the chip area and the dummy area are provided on the substrate, and even if the resin flows into the through hole from the front surface side of the substrate, the resin is applied to the back surface side of the substrate. Since the entire dummy area including the vicinity of the through hole strongly adheres to the mold, it is possible to sufficiently prevent the resin from sneaking into the back surface of the substrate through the through hole.

In a preferred embodiment of the method for manufacturing an infrared data communication module according to the first aspect, a wiring pattern is formed in the chip area, and the wiring pattern is formed in the dummy area. , A dummy pattern corresponding to the overall shape of the wiring pattern may be formed.

According to such a configuration, the chip area on the front surface side of the substrate is provided with a wiring pattern having a certain thickness, while the dummy area on the rear surface side of the substrate is provided with the wiring pattern. Since a dummy pattern having a partial thickness is provided correspondingly, the portion where the chip area and the dummy area are provided on the substrate is slightly thick overall, and the surface pressure in such a thick portion is sufficient. As a result, the adhesion between the substrate and the mold can be kept better, and the resin can be reliably prevented from flowing around the back surface of the substrate through the through holes.

In another preferred embodiment, the dummy pattern may have a thickness equal to a thickness of a conductor layer bordering the outer shape of the dummy area including the lower periphery of the through hole.

According to this structure, the rear surface of the substrate is entirely flat by the dummy area including the dummy pattern and the conductor layer surrounding the dummy area. When a member having a flat surface is closely attached to the side, the entire back surface of the substrate including the vicinity of the through hole is uniformly pressed, and it is possible to reliably prevent the resin from flowing to the back surface of the substrate through the through hole. .

In another preferred embodiment, when the resin package is formed, two or more sets of the light emitting element and the light receiving element are collectively sealed by one common resin package. It can be.

According to such a configuration, the number of steps for cutting the resin package and the substrate can be reduced, and the production efficiency of the infrared data communication module can be increased.

The infrared data communication module provided by the second aspect of the present invention is characterized by being manufactured by the method for manufacturing an infrared data communication module provided by the first aspect of the present invention.

According to the infrared data communication module provided by the second aspect of the present invention, the same effect as that obtained by the first aspect can be expected.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

1 to 12 show an example of a method for manufacturing an infrared data communication module according to the present invention. To manufacture an infrared data communication module, first, a substrate 1 as shown in FIGS. 1 and 2 is used. FIG. 1 is a diagram illustrating the front side of the substrate 1, and FIG. 2 is a diagram illustrating the rear side of the substrate 1. The substrate 1 is made of, for example, glass epoxy resin, and has a band shape or an elongated rectangular shape extending in a certain direction. On the front surface 10a of the substrate 1, a wiring pattern (a part of which is not shown) required for one infrared data communication module is formed for each chip area 19. The wiring pattern 70 has a pad portion for mounting a light emitting element, a light receiving element, and an LSI chip described later, an electrode terminal portion, and the like. FIG. 1 shows only the pad portion. Tip area 19
Are provided side by side in the longitudinal direction and the width direction of the substrate 1. In the vicinity of a longitudinal boundary defined as such a chip area 19, through holes 7 penetrating in the thickness direction of the substrate 1 are provided in a line. On the other hand, a dummy area 21 having the same size as the chip area 19 is formed on the back surface 10 b of the substrate 1 so as to be opposite to the chip area 19. In the dummy area 21, a dummy pattern 22 having the same size as the entire area of the wiring pattern 70 in the chip area 19 is provided. Also, near the boundary of the dummy area 21, a through hole 7 penetratingly formed in the thickness direction of the substrate 1 is located.

3 and FIG. 4, the chip area 1 on the surface 10a of the substrate 1 will be described in detail.
Numeral 9 is formed by forming a thin film of the conductor layer 10 on the entire surface 10a, and then removing the rectangular partition area corresponding to the chip area 19 by etching or the like. At the time of this etching or the like, a conductor portion required as the wiring pattern 70 is left in the chip area 19. The through hole 7 has a conductor film 7 a on an inner wall portion along the axial direction, and the conductor film 7 a is connected to the conductor layer 10. On the other hand, like the chip area 19, the dummy area 21 on the back surface 10b of the substrate 1
0 is formed by forming a thin film, and then removing a rectangular section area corresponding to the dummy area 20 by an etching process or the like. At the time of this etching process or the like, a portion required as the dummy pattern 22 is left in the dummy area 21. The through hole 7 has a shape in which the conductor film 7 a on the inner wall portion is connected to the conductor layer 20. In other words, on the surface 10 a of the substrate 1, the conductor layer 10 that borders the outer shape of the chip area 19 and extends to the upper periphery of the through hole 7 and the wiring pattern 70 in the chip area 19 have the same thickness. Formed. On the other hand, on the back surface 10b of the substrate 1, a dummy area 21 is provided.
A conductor layer 20 which borders the outer shape of FIG.
2 are formed with the same thickness as each other. Therefore, the back surface 10b side of the substrate 1 is formed as a substantially flat surface with few undulations as a whole by the large number of dummy areas 21 including the dummy patterns 22 and the conductor layer 20 surrounding these. The reason for providing the dummy area 21 will be described later.

Further, the substrate 1 is provided with a plurality of slits 18 at intervals in the longitudinal direction, and these slits 18 extend in the width direction of the substrate 1. The plurality of slits 18 help prevent the substrate 1 from warping and deforming in the longitudinal direction when a resin package is formed on the substrate 1 as described later.

Subsequently, in each chip area 19 on the surface 10a of the substrate 1, as shown in FIGS. 5 to 7, the light emitting element 2, the light receiving element 3 and the light receiving element 3 face the pad portion of the wiring pattern 70. The LSI chip 6 is mounted.
The light emitting element 2 is composed of, for example, an infrared light emitting diode. The light receiving element 3 is, for example, a PIN capable of sensing infrared rays.
It consists of a photodiode. The LSI chip 6 controls transmission and reception of infrared rays by the light emitting element 2 and the light receiving element 3, and specifically includes a modulation / demodulation circuit, a waveform shaping circuit, and the like. Further, the light emitting element 2, the light receiving element 3, and the LSI chip 6 are connected to the electrode terminals of the wiring pattern 70 by wire bonding. The light emitting element 2, the light receiving element 3, and the LSI chip 6 are electrically connected to the through hole 7 via the wiring pattern 70. In addition,
A part of the conductor layer 20 connected to the conductor film 7a of each through hole 7 on the back surface 10b of the substrate 1 is called a terminal 71.

Next, as shown in FIG. 8, a plurality of resin packages 4 are formed on the surface 10a of the substrate 1. Each resin package 4 is made of, for example, an epoxy resin containing a pigment, and does not transmit visible light, but transmits infrared light sufficiently well. Each resin package 4 has one area 1
9 are not sealed, but a set of electronic components on two chip areas 19 adjacent to each other in the longitudinal direction of the substrate 1, that is, two light emitting elements 2 and two light receiving elements The element 3, the LSI chip 6, and their peripheral regions are formed so as to be collectively sealed. Therefore, when, for example, eight chip areas 19 are provided side by side on the surface 10a of the substrate 1, a total of four resin packages 4 are formed side by side in that direction. Gap 92 between each
Are three places in total.

As described above, according to the process of forming the resin package 4, the total number of the gaps 92 is reduced as compared with the case where the resin package is formed independently for each electronic component group in one chip area 19. be able to. Therefore, in the present embodiment, it is possible to reduce a useless space on the board 1 and increase the number of infrared data communication modules in the longitudinal direction of the board 1. If an appropriate number of gaps 92 are provided in the longitudinal direction of the substrate 1, the substrate 1 is moved in the longitudinal direction due to the resin package 4 being provided in close contact with only the surface 10 a of the substrate 1. The effect of appropriately preventing or suppressing warping deformation can be obtained.

On the other hand, in the width direction of the substrate 1, a plurality of resin packages 4 are formed so that one chip area 19 corresponds to one resin package 4. Therefore, an appropriate number of gaps 93 are provided between the plurality of resin packages 4 also in the width direction of the substrate 1. This makes it possible to appropriately prevent or suppress the substrate 1 from being warped and deformed in the width direction due to the provision of the resin package 4 on the substrate 1.

As shown in FIG. 9, each of the resin packages 4 has a mold P for the front surface and the back surface.
For example, it can be formed by transfer molding using P1, P2, and formed, for example, as follows.
That is, a mold having a cavity 4a corresponding to the shape of the resin package 4 is used for the front mold P1, but a mold P2 for the back is flat facing the back 10b side of the substrate 1. What has the pressing surface P2a is used.
The cavities 4a in the front surface mold P1 are connected so that the respective rows along the width direction of the substrate 1 share a space via a gate (not shown). Then, the surface mold P1 is accurately positioned on the surface 10a of the substrate 1 such that each cavity 4a surrounds two chip areas 19. On the other hand, the mold P2 on the back side simply faces the entire back side 10b of the substrate 1 and is simply pressed. In this way, between the two dies P1 and P2, the substrate 1 is pressed and held by the two dies P1 and P2, and the cavity 4 is formed through the liner 4b.
After the resin is injected into a, the two molds P
By opening 1, P2, a molded product shown in FIG. 8 is obtained.

When molding such a resin package 4,
As shown in FIG. 10, the resin on the chip area 19 passes through the through hole 7 and
It is conceivable that there is a possibility of wraparound to the b side. However, in the vicinity of the through hole 7 on the back surface 10b side of the substrate 1, a flat surface with as little undulation as possible is formed by the dummy pattern 22 having the same thickness as the conductor layer 20 and the terminals 71 in addition to the conductor layer 20 and the terminals 71. . Therefore, both molds P
In the state where the substrate 1 and the substrate P2 press the substrate 1, the pressing force acts uniformly on the front and back surfaces 10a and 10b of the substrate 1, and the surface pressure of the overlapping portion between the chip area 19 and the dummy area 21 is sufficiently increased. . In particular, the mold P2 for the back side
The pressing surface P2a is in close contact with the conductor layer 20 including the vicinity of the through hole 7 on the back surface 10b of the substrate 1, the terminal 71, and the dummy pattern 22 without any gap. In short, the through hole 7 is reliably closed by the flat pressing surface P2a of the mold P2 on the back surface 10b of the substrate 1, and even if the resin flows into the through hole 7 from the front surface 10a side of the substrate 1, the back surface 10b side In this case, the resin does not overflow to the outside of the through-hole 7, thereby preventing the resin from flowing around.

Each resin package 4 thus molded
10 and 11, a plurality of side surfaces 40 rising upward from the surface 10a of the substrate 1,
The ceiling surface 41 connected to the upper end 42 of the plurality of side surfaces 40
And The plurality of side surfaces 40 are provided in the surface mold P1.
All of them are inclined surfaces due to the draft angle provided in the cavity portion 4a. The ceiling surface 41 is located above the light emitting element 2 and the light receiving element 3. The ceiling surface 41 has a pair of lenses 43a and 43b, each of which is partly bulged upward.
Is provided. These pair of lenses 43a, 43b
Is for imparting directivity to the light emitting characteristics of the light emitting element 2 and the light receiving characteristics of the light receiving element 3. As shown in FIG. 10, the openings are closed by a suitable resist film (not shown) in each through-hole 7, so that the resin does not normally flow into the through-hole. Even in such a form, the resist film may be melted together with the high-temperature resin, and then the resin tends to flow around the back surface 10 b of the substrate 1 through the through hole 7. However, since the opening of the through hole 7 is securely closed by the close contact of the pressing surface P2a of the mold P2 for the back surface, the resin does not adhere to the back surface 10b side of the substrate 1.

After the resin package 4 is formed,
The substrate 1 is cut. However, in this case, the cutting operation of the resin package 4 is also performed. More specifically, the substrate 1 and the resin package 4 are cut at positions indicated by virtual lines La to Ld in FIG. In a first cutting step for cutting the position indicated by the virtual line La, the ceiling surface 41 of the resin package 4 is attached to the base 45 of the lenses 43a and 43b.
(In the present embodiment, the base portion 45 means a boundary portion between the flat portion of the ceiling surface 41 and the lenses 43a and 43b) or in the vicinity thereof, so that the resin package 4 and the substrate 1 are cut in their thickness direction. This is the step of cutting into pieces. The cut portion is located closer to the widthwise inner side of the resin package 4 by an appropriate dimension Sa than the upper end 42 of the side surface 40. This cutting operation can be performed using a drive-rotatable blade 5 having a predetermined thickness, which will be described later, and is performed by moving one side surface of the blade 5 along a virtual line La. The through hole 7 is provided so as to be located on the virtual line La, and the first cutting step is performed so as to divide the through hole 7.

The second cutting step is a step of cutting a portion corresponding to the center of the resin package 4 in the width direction, and cuts the positions indicated by the imaginary lines Lb and Lc. Virtual lines Lb, Lc
Pass through or near the base 45 of the lenses 43a and 43b, but the imaginary line Lc also passes through the through hole 7. The thickness t of the blade 5 is determined by two imaginary lines Lb,
It is the same size as the interval of Lc. Therefore, in the second cutting step, the resin package 4 and the substrate 1 can be cut at the positions of the two virtual lines Lb and Lc by one cutting operation. In the third cutting step, the virtual line Ld
Is a step of cutting the position indicated by, and this step is substantially the same as the above-described first cutting step. In the longitudinal direction of the substrate 1, the resin package 4 and the substrate 1 are cut in the thickness direction in the same manner as described above.

The work of cutting the substrate 1 is also performed in the width direction of the substrate 1. In this case, for example, a virtual line L shown in FIG.
The resin package 4 and the substrate 1 are cut at the position e.
This cutting operation is an operation of cutting the resin package 4 and the substrate 1 at or near the base 45 of the lens 43a or 43b, similarly to the cutting step using the imaginary lines La and Ld shown in FIG. .

According to such a series of working steps, FIG.
A plurality of infrared data communication modules A shown in FIGS. 3 to 15 will be manufactured. This infrared data communication module A is a resin package in which a light emitting element 2, a light receiving element 3, and an LSI chip 6 are mounted one by one on a substrate 1a cut into a rectangular shape, and these are cut on all sides. The structure is sealed by 4a.
From the resin package 4, all of the plurality of side surfaces 40 inclined with respect to the substrate 1a are removed. The plurality of side surfaces 40a of the resin package 4a are all smooth planar cut surfaces, and are flush with the cut surface 11 of the substrate 1a. Therefore, the infrared data communication module A
The plurality of outer surfaces include two flat surfaces 8A and 8B in which the cut surface 11 and the side surface 40a are connected in a plane. Each plane 8A extends in the longitudinal direction of the infrared data communication module A, and each plane 8B is a plane orthogonal to the plane. A plurality of recesses 7A formed by dividing the plurality of through holes 7 are provided in one plane 8A, and the conductor films 7 connected to the plurality of terminals 71 are provided.
a has a structure exposed to the outside.

According to the above series of working steps, FIG.
15 can be manufactured separately, but in particular, in the step of forming the resin package 4, the molds P1 and P2 are formed in the chip area 19 and the dummy area 21 of the substrate 1. Surface pressure is sufficiently applied. Therefore, on the back surface 10 b side of the substrate 1, the back surface mold P <b> 2 is brought into tight contact with the terminal 71 near the through hole 7 and the entire dummy area 21 where the dummy pattern 22 is formed. The infrared data communication module A having the resin package 4a only on the front surface 10a side of the substrate 1 can be obtained without the resin wrapping around the back surface 10b side of the substrate 1.

The present invention is not limited to the above embodiment.

For example, when the resin package 4 is formed to seal the light-emitting element 2 and the light-receiving element 3, it is not always necessary to form two sets of them and collectively seal them. For example, three or more sets of light emitting elements and light receiving elements may be collectively sealed. In the present invention, as the number of combinations of the light emitting element and the light receiving element sealed by one resin package is increased,
The number of gaps formed between a plurality of resin packages can be reduced, and the number of single infrared data communication modules taken out from one molded product can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a front side of a substrate used in a method of manufacturing an infrared data communication module according to the present invention.

FIG. 2 is a perspective view showing the back side of the substrate shown in FIG. 1;

FIG. 3 is a sectional view taken along line II-II of FIG.

FIG. 4 is a sectional view taken along line III-III of FIG. 1;

FIG. 5 is a perspective view showing a state where an electronic component group is mounted on the substrate shown in FIG. 1;

FIG. 6 is a sectional view taken along line IV-IV of FIG. 5;

FIG. 7 is a sectional view taken along line VV of FIG. 5;

FIG. 8 is a perspective view showing a state in which a resin package is formed on the substrate shown in FIG.

9 is a perspective view showing a state when the molded article shown in FIG. 8 is molded using a mold.

FIG. 10 is a sectional view taken along line VI-VI of FIG. 8;

11 is a sectional view taken along line VII-VII of FIG.

FIG. 12 is a cross-sectional view showing a cutting step of the resin package and the substrate.

FIG. 13 is a cross-sectional view showing an example of an infrared data communication module manufactured through a manufacturing method according to the present invention.

FIG. 14 is a sectional view taken along line IX-IX of FIG.

FIG. 15 is a left side view of FIG.

[Explanation of symbols]

 A Infrared data communication module P1 Mold (for front surface) P2 Mold (for back surface) 1,1a Substrate 2 Light emitting element 3 Light receiving element 4,4a Resin package 6 LSI chip 10 Conductive layer 19 Chip area 20 Conductive layer 21 Dummy Area 22 Dummy pattern 70 Wiring pattern

Claims (5)

[Claims] 1. A chip area for mounting a set of a light emitting element and a light receiving element by partitioning each set on a surface of a substrate, and a through hole penetrating through the chip area in a thickness direction of the substrate. When encapsulating the light emitting element and the light receiving element mounted on each of the chip areas, a resin package is formed on a surface of the substrate using a resin molding die. In a method for manufacturing a module, before forming the resin package on the front surface of the substrate, a dummy area of the same size as the chip area is defined at each location on the back surface of the substrate opposite to the chip area. A method of manufacturing an infrared data communication module, characterized in that the module is formed. 2. A wiring pattern is formed in the chip area, and a dummy pattern corresponding to the overall shape of the wiring pattern is formed in the dummy area while being opposite to the wiring pattern. The method for manufacturing an infrared data communication module according to claim 1. 3. The method of manufacturing an infrared data communication module according to claim 2, wherein said dummy pattern has a thickness equal to a thickness of a conductor layer bordering an outline of said dummy area including a lower periphery of said through hole. 4. When forming the resin package,
4. The method of manufacturing an infrared data communication module according to claim 1, wherein two or more sets of the light emitting element and the light receiving element are collectively sealed with one common resin package. 5. An infrared data communication module manufactured by the method for manufacturing an infrared data communication module according to claim 1. Description: