JP4852991B2 - Electronic components - Google Patents

Description

  The present invention relates to an electronic component in which a chip is disposed in a cavity provided on a substrate.

  A chip such as an oscillation IC chip or MMIC (Monolithic Microwave Integrated Circuit) is placed through a solder bump in a rectangular cavity formed on the bottom of the container, and resin is placed in the gap formed between the chip and the cavity. For example, electronic parts filled with a material such as those described in Patent Document 1 and Patent Document 2 are known.

  For example, in Patent Document 1, as shown in FIG. 10, a cavity 102 surrounded by ceramic layers 101a, 101b, and 101c, and an oscillation bump disposed in the cavity 102 via an Au bump 103 and an electrode pad 104 An electronic component 100 having an IC chip 105 is disclosed. The oscillation IC chip 105 is fixed by filling a gap in the cavity 102 other than the oscillation IC chip 105 with a thermosetting resin 106 for underfilling, heating, and curing.

Further, Patent Document 2 discloses an electronic component 107 having an MMIC 111 arranged via a solder bump 110 in a substrate 109 having a cavity 108 as shown in FIG. The MMIC 111 is fixed to the substrate 109 by covering the MMIC 111 and the cavity 108 with the resin 112 being in non-contact with the one main surface 111a of the MMIC 111 facing the cavity bottom surface 113.
JP 2002-50652 A In the method of fixing the chip to the cavity as described above, unnecessary stress is applied to the chip due to resin shrinkage in the resin heating / curing process, and in the worst case, the chip is destroyed. There was a problem that. As a result, an abnormality that the operation of the electronic component becomes unstable or stops operating may occur.

  Furthermore, when the underfill method is used, the distance between the cavity side surface and the chip side surface facing the cavity side surface is made sufficiently large with respect to the diameter of the solder bump to suppress the formation of voids formed in the resin. It was necessary and it was difficult to make the electronic component small.

  The present invention has been devised in view of the above-mentioned problems, and its object is to reduce chip stress by reducing the stress that the chip receives from the resin and stably fixing the chip to the cavity. Another object is to provide an electronic component capable of stable operation.

In order to solve the above-mentioned problem, the electronic component according to the first invention is
A substrate having a cavity on the back surface ;
A chip housed in the cavity,
The cavity has a cavity bottom surface and a cavity side surface,
The chip has one main surface facing the cavity bottom surface, the other main surface facing the one main surface, and a chip side surface facing the cavity side surface,
In the side space formed between the side surface of the chip and the side surface of the cavity, a resin part for only fixing the chip to the cavity and a gap part in which no resin part is provided are arranged,
A bottom space formed between one main surface of the chip, the side space, and the bottom of the cavity;
A conductor protrusion disposed in the bottom space for electrically connecting the chip and the substrate;
The gap and the bottom space arranged in the side space are connected to each other, and the bottom space is connected to the outside via the gap,
From the back side, you can see a part of the bottom of the cavity through the gap,
The resin portion is not filled in the bottom space.
In the electronic component according to the second invention, the cavity and the chip are formed in a rectangular shape,
The side space is formed by first to fourth side spaces formed between the cavity side surface and the chip side surface, and first to fourth corner spaces sandwiched between the first to fourth side spaces. ,
The first side space and the second side space are arranged to face each other,
The third side space and the fourth side space are arranged to face each other,
The first corner space and the second corner space are arranged to face each other,
The third corner space and the fourth corner space are arranged to face each other,
The resin portion is formed in at least a pair of the first corner space and the second corner space,
The gap is formed in the first to fourth side spaces.
In the electronic component according to the third invention, the cavity and the chip are formed in a rectangular shape,
The side space is formed by first to fourth side spaces formed between the cavity side surface and the chip side surface, and first to fourth corner spaces sandwiched between the first to fourth side spaces. ,
The first side space and the second side space are arranged to face each other,
The third side space and the fourth side space are arranged to face each other,
The first corner space and the second corner space are arranged to face each other,
The third corner space and the fourth corner space are arranged to face each other,
The resin portion is formed in at least a part of the pair of first side space and second side space,
The gap is formed in the first to fourth corner spaces.
An electronic component according to a fourth invention is characterized in that the resin portion is formed in the entire pair of first side space and second side space.
An electronic component according to a fifth invention is characterized in that the cavity is formed of a two-stage cavity having an upper stage cavity and a lower stage cavity, and the opening of the lower stage cavity is formed smaller than one main surface of the chip. To do.
An electronic component according to a sixth aspect is characterized in that the resin portion is formed at a position lower than the other main surface of the chip.
In the electronic component according to the seventh invention, the substrate is formed of a first main surface on which a cavity is formed, and a second main surface facing the first main surface,
The external connection terminal is disposed on the first main surface where the cavity of the first main surface is not formed,
The surface mount component is arranged on the second main surface.

  According to the electronic component of the first invention, the stress generated when the resin is heated and cured can be absorbed by the gap, so that unnecessary stress can be prevented from being transmitted to the chip. Furthermore, the chip is stably fixed to the cavity by the resin portion, and the chip can be prevented from being detached from the cavity due to unnecessary vibration.

  Furthermore, since the periphery of the conductor protrusion is an open space without an adhesive resin, occurrence of a short circuit due to solder flash can be suppressed.

According to the electronic component of the second invention, the chip can be fixed to the cavity with a small amount of resin, so that the manufacturing cost can be reduced.

According to the electronic component according to the third and fourth inventions, the chip can be stably fixed to the cavity, so that the destruction of the chip due to vibration or the like can be suppressed.

According to the electronic component of the fifth invention, it is possible to reliably prevent the adhesive resin formed in the side space and the corner space from flowing into the lower cavity where the conductor protrusion is disposed. I can do it.

According to the electronic component of the sixth aspect of the present invention, since the adhesive resin is not formed on the other main surface of the chip, more surface mount components can be formed on the other main surface of the chip.

According to the electronic component of the seventh invention, many surface mount components can be arranged on the substrate, and the electronic component can be effectively arranged on the mother substrate, so that space saving can be achieved. It becomes possible.

  Embodiments of the present invention will be described below with reference to the drawings. Here, the same symbols are attached to the same members in the accompanying drawings. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

(Embodiment 1)
1 is a cross-sectional view of an electronic component mounted on a mother board (not shown) in Embodiment 1 of the present invention, FIG. 2 (A) is a perspective view when the electronic component is viewed from the back surface, and FIG. 2 (B) is a diagram. 2 (A) is a plan view when viewed from the back side, and FIG. 2 (C) is a cross-sectional view taken along line AA in FIG. 2 (A).

  The electronic component 1 according to the present embodiment includes a ceramic multilayer substrate 4 having a rectangular cavity 3 on the back surface 2, a resistor 6, a capacitor 7, and an LGA type SAW filter 8 disposed on the upper surface 5 of the ceramic multilayer substrate 4. The surface mount component such as the above, the metal case 9 that covers the surface mount component and is disposed on the upper surface 5, and the mother substrate (not shown) are connected to the portion on the back surface 2 where the cavity 3 is not formed. External connection terminals 23, rectangular chips 10 such as MMICs, oscillation ICs, FCICs (Flip Chip Integrated Circuits) that are high-frequency devices arranged in the cavity 3, and a chip that faces the cavity bottom surface 15 Chip one main surface 11 for electrically connecting the chip 10 and the ceramic multilayer substrate 4 via the conductor protrusion 12 and the conductor protrusion 12 such as a solder bump or a stud bump arranged between the surface 11 And mold Has an electrode pad (not shown) disposed on the I bottom 15.

  Further, the cavity is sandwiched between the side surface spaces 16a, 16b, 16c, and 16d (see FIG. 2B) formed between the cavity side surface 18 and the chip side surface 19 that faces the cavity side surface 18. In the corner spaces 32a, 32b, 32c, and 32d (see FIG. 2 (B)), the gap 13 (see FIG. 2 (B) and FIG. 2 (C)) and the chip 10 are fixed to the cavity 3. An adhesive resin 14 is provided. As the adhesive resin 14, for example, an epoxy resin or a silicon resin having a viscosity of 100 to 350 Pa · S is used. The side spaces 16a, 16b, 16c, 16d are formed clockwise from the front side in FIG. 2 (B), and the corner spaces 32a, 32b, 32c, 32d are formed from the right front side in FIG. 2 (B). Yes.

  When filling the adhesive resin 14 only in the side spaces 16a to 16d and in the corner spaces 32a, 32b, 32c, 32d, the chip one main surface 11, the side spaces 16a, 16b, 16c, 16d, and the cavity bottom surface 15 The distance X between the chip one main surface 11 and the cavity bottom surface 15 and the space between the cavity side surface 18 and the chip side surface 19 in the bottom space 17 formed between It is desirable that the relationship with the distance W be X> W. The reason for this relationship is to prevent the adhesive resin 14 from flowing into the bottom space 17 by capillary action. In the first embodiment, the adhesive resin 14 is filled so as to be lower than the chip one main surface 11. This prevents the adhesive resin 14 from entering the bottom space 17 reliably.

  Although the cavity 3 and the chip 10 of the first embodiment are rectangular, the present invention is not limited to this shape, and the same effect can be obtained by a cylindrical shape, a triangular shape, or the like. The same effect can be obtained even when a plurality of chips 10 are arranged in the cavity 3.

  A plurality of external connection terminals 23 for electrical connection with a mother substrate (not shown) are formed in a portion other than the cavity 3 formed on the back surface 2. For example, a total of six external connection terminals 23 are arranged on the side surface in the vertical direction of the back surface 2 and two in total on the side surface in the horizontal direction. Note that the external connection terminals 23 may be appropriately arranged for connection to a mother board (not shown), and are not limited to the arrangement position and quantity in the present embodiment.

  The adhesive resin 14 is formed of an adhesive resin 14a formed in the corner spaces 32a to 32d and an adhesive resin 14b formed in a part of each of the side spaces 16a to 16d. The adhesive resin 14a and the adhesive resin 14b are formed continuously. A gap 13 is formed in a portion where the adhesive resins 14a and 14b are not formed. As a result, when the adhesive resins 14a and 14b are heated and cured, the amount of heat transferred from the adhesive resin 14 to the chip 10 can be minimized, and the stress generated when the adhesive resin 14 is cured is transmitted to the chip 10. Therefore, it is possible to reduce the occurrence of defective products of the electronic component 1 due to the breakage of the chip 10. Furthermore, since the adhesive resins 14a and 14b are filled in the corner spaces 32a to 32d and part of the side spaces 16a to 16d, the chips are stably fixed.

  Incidentally, in the direction parallel to each side of the chip other principal surface 20, the total length of the contact portion 25 where the adhesive resin 14b and the chip 10 are in contact, and the total length of the non-contact portion 26 that is not in contact Are compared, the length of the contact portion 25 is shorter than the length of the non-contact portion 26. Thereby, the chip 10 can be efficiently placed and fixed in the cavity 3 with a small amount of the adhesive resin 14.

  The gap 13 in the first embodiment is formed in the entire space between the non-contact part 26 and the cavity side surface 18 in the side spaces 16a to 16d. Therefore, as in the first embodiment, when the bottom space 17 is not filled with the adhesive resin 14, the gap 13 and the bottom space 17 are connected to each other. Further, from the back surface 2 side, a part of the cavity bottom surface 15, the cavity side surface 18 and the chip side surface 19 can be seen through the gap 13.

  FIG. 3 shows a modification of the first embodiment. In the first embodiment, the adhesive resins 14a and 14b are filled in the corner spaces 32a to 32d and a part of the side spaces 16a to 16d, but in this modification, a pair of opposite corner spaces 32a , 32c, and part of the side spaces 16a to 16d in contact with the pair of corner spaces 32a and 32c, respectively, are formed with adhesive resins 14a and 14b. When the electronic component 1 is used in a stable place, it is only necessary to arrange the adhesive resins 14a and 14b in the above portion.

  Since the electronic component 1 according to the first embodiment and the modification of the first embodiment does not fill the bottom space 17 with the adhesive resin 14, the voids formed in the adhesive resin when using the underfill method, that is, the generation of voids Can be suppressed. Further, since the conductor protrusion 12 is not covered with the adhesive resin 14, it is possible to eliminate occurrence of a short circuit from the conductor protrusion 12 due to solder flash. Furthermore, since it is not necessary to spread the adhesive resin 14 over the entire bottom space 17, the distance between the cavity side surface 18 and the chip side surface 19 does not need to be sufficiently larger than the distance between the chip one main surface 11 and the cavity bottom surface 15, The cavity 3 can be made small. Therefore, space saving and product size reduction can be realized. Furthermore, by making the cavity 3 small, the portion other than the cavity 3 formed on the back surface 2 of the ceramic multilayer substrate 4 can be substantially widened. As a result, the number of external connection terminals 23 formed can be increased, and the resistance of the electronic component to mechanical strength can be improved.

(Embodiment 2)
4A and 4B are a plan view and a cross-sectional view, respectively, showing the electronic component 1 according to Embodiment 2 of the present invention. The second embodiment is the same as the first embodiment except for the position where the adhesive resin 14 is filled.

  In electronic component 1 according to Embodiment 2 of the present invention, adhesive resin 14 is filled in the entire pair of side spaces 16a and 16c facing each other. In addition, a gap 13 is formed in the side spaces 16b and 16d and the entire corner spaces 32a to 32d. For this reason, a part of the cavity bottom surface 15 can be seen through the gap 13 from the back surface 2 side.

In addition, although the adhesive resin 14 is formed over the entire side surface spaces 16a and 16c in the second embodiment of the present invention, the adhesive resin may be formed only in a part of the side space.
FIG. 4B is a cross-sectional view of the electronic component 1 of FIG. 4A cut along the line BB. Although the adhesive resin 14 is formed in almost the entire side space 16a, 16c, the bottom surface space 17 is not filled with the adhesive resin 14.

  In the electronic component 1 according to the second embodiment of the present invention, the adhesive resin 14 is formed over almost the entire pair of side spaces 16a and 16c facing each other, so that the cavity size can be reduced and the product size can be reduced. I can do it.

  Although not shown, the gap 13 and the bottom space 17 in the second embodiment are connected to each other.

  FIG. 5A and FIG. 5B are modifications of the second embodiment. In the second embodiment, the adhesive resin 14 is formed in the entire side space 16a, 16c, but in this modification, the adhesive resin 14 is formed in almost the entire side space 16a, 16b, 16d. A space 13 is formed in the entire space 16c and the corner spaces 32a to 32d.

  FIG. 5B is a cross-sectional view of the electronic component 1 of FIG. 5A cut along the line CC. An adhesive resin 14 is formed in the side space 16a, and a gap 13 is formed in the side space 16c. The gap 13 and the bottom space 17 are connected to each other. Thereby, since a cavity dimension can be made small, a product size can be made small.

(Embodiment 3)
FIG. 6 is a back plan view showing electronic component 1 according to Embodiment 3 of the present invention. The third embodiment is the same as the first embodiment or the second embodiment except for the position where the adhesive resin 14 is filled. In the third embodiment, the adhesive resin 14 is formed on the lateral centerline 30 and the longitudinal centerline 31 of the chip (or cavity) in the side spaces 16a to 16d, and on the lateral centerline 30 and the longitudinal centerline. It is formed in the vicinity of 31. The adhesive resin 14 is arranged so that a part of the side spaces 16a, 16b, 16c, 16d, specifically, the proportion of the adhesive resin 14 in each side space is 20% to 30%, and the rest A gap 13 is disposed in the portion. Thereby, the amount of resin can be reduced and the cost can be reduced.

(Embodiment 4)
FIGS. 7A to 7D are a back plan view and a cross-sectional view showing electronic component 1 in the fourth embodiment of the present invention. The fourth embodiment is the same as the first to third embodiments except for the filling position of the adhesive resin 14. The adhesive resin 14 in the present fourth embodiment is formed in the side spaces 16a, 16b, 16c, the entire corner spaces 32a to 32d, and a part of the side space 16d. Therefore, the adhesive resin 14 and the gap 13 are formed in the side space 16d.
FIG. 7B is a cross-sectional view taken along the line DD in FIG. The adhesive resin 14 is formed in the entire side space 16b, and the gap 13 is formed in the side space 16d. In addition, since the adhesive resin 14 is not filled in the bottom space 17, the gap 13 and the bottom space 17 are connected to each other.

  FIG. 7C is a cross-sectional view taken along the line E-E in FIG. Adhesive resin 14 is formed almost entirely in the side spaces 16a and 16c.

(Reference Example 1)
FIG. 7D is a cross-sectional view taken along the line DD when the adhesive resin 14 is filled in the bottom space 17. In this case, a part of the surface of the adhesive resin 14 can be seen from the back surface 2 side of the electronic component 1 through the gap 13.

(Embodiment 5)
FIG. 8 is a cross-sectional view showing electronic component 1 according to Embodiment 5 of the present invention. In the fifth embodiment, a cavity formed in the ceramic multilayer substrate 40 for accommodating the chip 10 and the conductor protrusion 12 is formed in a two-stage structure of an upper stage cavity 41 and a lower stage cavity 42. Further, the opening 45 of the lower cavity is formed smaller than the chip one main surface 11. In addition, the arrangement | positioning correspondence of the adhesive resin 14 and the space | gap 13 except the cavity having a two-stage configuration is the same as in the first to fourth embodiments.

  The lower cavity 42 can accommodate the conductor protrusions 12 for electrically connecting the chip 10 and the ceramic multilayer substrate 40. Further, when the chip is disposed in the upper cavity 41 via the conductor protrusion 12, the lower cavity height J is such that a part of the upper cavity bottom surface 43 and a part of the chip one main surface 11 are in contact with each other. It is determined to be able to face each other through the clearance. Specifically, the lower cavity height J is determined so that the relationship between the distance K between the chip main surface 11 and the lower cavity bottom surface 44 and the lower cavity height J satisfies K ≧ J. The distance K is determined based on the height of the conductor protrusion 12. Thereby, it is possible to reliably prevent the adhesive resin 14 from flowing into the lower cavity 42.

(Reference example 2)
In Embodiments 1 to 5 of the invention, the chip 10 and the ceramic multilayer substrate 4 or 40 are electrically connected via the conductor protrusions 12, but the chip 10 and the ceramic multilayer substrate 4 are connected by wire bonding. Or 40 may be connected.

  FIG. 9 (A) and FIG. 9 (B) are a back plan view and a cross-sectional view showing electronic component 1 according to Embodiment 6 of the present invention. Note that FIG. 9B is a cross-sectional view taken along line FF in FIG. 9A.

  A two-stage cavity having an upper cavity 51 and a lower cavity 52 is formed on the back surface 2 of the ceramic multilayer substrate 50 constituting the electronic component 1. The chip 10 is disposed in the lower cavity 52. The bonding terminal 53 on the chip 10 and the bonding electrode 54 on the upper cavity bottom surface 56 are electrically connected via a wire 55.

  The gap 13 and the adhesive resin 14 are formed in a part of the side spaces 16a to 16d and the entire corner spaces 32a to 32d, and the gap 13 is formed in other portions where the adhesive resin 14 is not formed. ing.

  As a result, a part of the bottom cavity bottom surface 57 or a part of the shield electrode formed on the bottom cavity bottom surface 57 (not shown) can be seen from the back side of the electronic component 1 through the gap 13. In the sixth embodiment, the adhesive resin 14 is formed in a part of the side spaces 16a to 16d and the entire corner spaces 32a to 32d. However, the present invention is not limited to this, and the first to fifth embodiments are not limited thereto. The contents disclosed in can be applied as they are.

1 is a cross-sectional view showing an electronic component in Embodiment 1 of the present invention. 1 is a perspective view as seen from the back side of the electronic component in FIG. FIG. 2 is a back plan view of the electronic component of FIG. FIG. 2B is a cross-sectional view taken along the line AA in the electronic component of FIG. 2A. FIG. 6 is a back plan view of a modification of the electronic component according to Embodiment 1 of the present invention. FIG. 6 is a plan view of the back surface of an electronic component according to Embodiment 2 of the present invention. FIG. 4B is a BB cross-sectional view of the electronic component in FIG. 4A. FIG. 11 is a back plan view of a modification example of the electronic component according to Embodiment 2 of the present invention. FIG. 5B is a CC cross-sectional view of the electronic component of FIG. 5A. FIG. 10 is a plan view of the back surface of an electronic component according to Embodiment 3 of the present invention. FIG. 10 is a plan view of the back surface of an electronic component according to Embodiment 4 of the present invention. FIG. 7B is a DD cross-sectional view of the electronic component in FIG. 7A. FIG. 7B is an EE cross-sectional view of the electronic component in FIG. 7A. FIG. 10 is a DD cross-sectional view of a modification example of the electronic component according to Embodiment 4 of the present invention. FIG. 10 is a cross-sectional view of an electronic component in a fifth embodiment of the present invention. FIG. 10 is a front view of an electronic component in a sixth embodiment of the present invention. FIG. 9B is an FF sectional view of the electronic component in FIG. 9A. It is sectional drawing of the conventional electronic component. It is sectional drawing of another conventional electronic component.

Explanation of symbols

1 ... Electronic components
2 ... Back side
3 ... cavity
4 ... Ceramic multilayer substrate
10 ... chip
11… Chip one side
13 ... Void
14, 14a, 14b ... Adhesive resin
16a, 16b, 16c, 16d ... side space
18 ... Cavity side
19… Chip side
32a, 32b, 32c, 32d ... corner space

Claims (7)

A substrate having a cavity on the back surface ;
A chip housed in the cavity;
An electronic component having
The cavity has a cavity bottom surface and a cavity side surface;
The chip has one main surface facing the cavity bottom surface, the other main surface facing the one main surface, and a chip side surface facing the cavity side surface,
In a side space formed between the side surface of the chip and the side surface of the cavity, a resin part for only fixing the chip to the cavity, and a gap part in which the resin part is not provided are arranged,
A bottom space formed between one main surface of the chip, the side space, and the bottom of the cavity;
A conductor protrusion disposed in the bottom space for electrically connecting the chip and the substrate;
The gap portion and the bottom space arranged in the side space are connected to each other, and the bottom space is connected to the outside through the gap portion,
From the back side, a part of the cavity bottom can be seen through the gap,
The electronic part is characterized in that the resin part is not filled in the bottom space. The cavity and the chip are formed in a rectangular shape,
The side space includes first to fourth side spaces formed between the cavity side surface and the chip side surface, and first to fourth corner spaces sandwiched between the first to fourth side spaces. And formed with
The first side space and the second side space are arranged to face each other,
The third side space and the fourth side space are arranged to face each other,
The first corner space and the second corner space are arranged to face each other,
The third corner space and the fourth corner space are arranged to face each other,
The resin portion is formed in at least a pair of the first corner space and the second corner space,
2. The electronic component according to claim 1, wherein the gap is formed in the first to fourth side spaces. The cavity and the chip are formed in a rectangular shape,
The side space includes first to fourth side spaces formed between the cavity side surface and the chip side surface, and first to fourth corner spaces sandwiched between the first to fourth side spaces. And formed with
The first side space and the second side space are arranged to face each other,
The third side space and the fourth side space are arranged to face each other,
The first corner space and the second corner space are arranged to face each other,
The third corner space and the fourth corner space are arranged to face each other,
The resin portion is formed in at least a part of a pair of the first side space and the second side space,
2. The electronic component according to claim 1, wherein the gap is formed in the first to fourth corner spaces. 4. The electronic component according to claim 3, wherein the resin portion is formed in the entire pair of the first side space and the second side space. The cavity is formed of a two-stage cavity having an upper cavity and a lower cavity,
5. The electronic component according to claim 1, wherein the opening of the lower cavity is formed smaller than one main surface of the chip. 6. The electronic component according to claim 1, wherein the resin portion is formed at a position lower than the other main surface of the chip. The substrate is formed of a first main surface on which the cavity is formed, and a second main surface facing the first main surface,
The external connection terminal is disposed on the first main surface in which the cavity of the first main surface is not formed,
7. The electronic component according to claim 1, wherein the surface mount component is disposed on the second main surface.