JP3497210B2 - Metal package - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal package that accommodates various semiconductor chips that operate at high frequencies.

[0002]

2. Description of the Related Art FIG. 8A is an external view of a conventional metal package. 1 metallic bottomed case (hereinafter "case"), also made of metal seal ring 2, multiple attached to a ceramic pin (conveniently sidewall 4 which is attached to the side wall 4-7 of the case 1 3 One of the ceramic terminals is shown). The ceramic terminal 3 is shown in FIG. 8 (b) and FIG.
As shown in (c), a convex ceramic body 3a
Is fitted into the concave portion 4a of the side wall 4, and the top portion 3b of the ceramic made of ceramic is pressed by the seal ring 2 as well as between the main body 3a and the side wall 4 and between the top portion 3b and the seal ring 2.
They are attached by brazing (generally silver brazing) between them. Reference numeral 3c denotes a conductive pattern that penetrates the inside and outside of the case 1, and transmits a signal from a semiconductor chip (not shown) incorporated in the case 1 to the outside of the case 1 or a signal from the outside to the semiconductor chip. It is for doing. Further, the upper surface of the seal ring 2 is closed by a metal flat plate (commonly called “cap”) (not shown) after the semiconductor chip is installed so as to seal the case 1.

Here, the ceramic terminal 3 is for high frequencies in which the conductive pattern 3c is a signal line and the body 3a and the crown 3b are dielectric layers, and a predetermined line impedance (characteristic impedance Zo) and the like are secured. In order to cope with high frequencies, it is necessary to make the dielectric layer thinner or narrower the width (La, Lb) as the operating frequency becomes higher. That is, the higher the operating frequency, the smaller the ceramic terminal 3 becomes. Note that La is the ceramic terminal 3
The width of the end surface of the case 1 facing the outside of the case 1, Lb is the width of the end surface of the ceramic terminal 3 facing the inside of the case 1, and La = L
b.

[0004]

By the way, the width of the recess 4a of the case 1 must be similarly narrowed as the size of the ceramic terminal 3 is reduced, but some error is unavoidable due to the limit of processing accuracy. Therefore, for example, when the width of the recess 4a of the case 1 is too wide with respect to the width (La, Lb) of the ceramic terminal 3 (that is, the clearance is excessive).
, The positional accuracy in the width direction of the ceramic terminal 3 becomes poor, and the brazing material (generally silver brazing material) between the ceramic terminal 3 and the recess 4a increases, and the thermal expansion coefficient of this brazing material (in the case of silver brazing material) 17 × 10 ^-6 / ° C.) Is larger than the thermal expansion coefficient of the ceramic terminal 3 (7.7 × 10 ^-6 / ° C.) By about one digit, thermal stress acts on the ceramic terminal 3 and cracks occur. However, there is a problem in that the airtightness of the case 1 may be impaired. [Purpose] Therefore, according to the present invention, the clearance between the concave portion of the case and the ceramic terminal can be freely adjusted, thereby improving the positional accuracy of the ceramic terminal in the width direction and preventing the occurrence of cracks or the like to improve reliability. The purpose is to provide an enhanced metal package.

[0005]

In order to achieve the above object, the present invention provides a metal package in which a recess is formed in a side wall of a metallic bottomed case, and a ceramic terminal is fitted in the recess and fixed by brazing. , To the ceramic terminal
Is a ground pattern and / or a signal line pattern (below
Bottom, a conductive pattern) is formed, and the width of each end of the recess and the ceramic terminal facing the inside and outside of the bottomed case, or the width of each end in the height direction of the recess and the ceramic terminal. It is characterized by different.

[0006] or, said width of each end of the ceramic pin facing the inside and outside of the bottomed case with different, and, having different widths of each end in the height direction of the recess and the ceramic terminal It is characterized by.

[0007]

In the present invention, since the planar shape (or cross-sectional shape) of the ceramic terminal and the recess is tapered, the relative horizontal position (or the vertical position) of the ceramic terminal and the recess is adjusted, and the space between them is adjusted. The clearance can be adjusted freely.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIGS. 1 to 4 are views showing a first embodiment of a metal package according to the present invention. First, the configuration will be described. In FIG. 1, 10 is a flat plate (cap), 11 is a seal ring, 1
Reference numeral 2 denotes a bottomed case (hereinafter referred to as “case”), and each of them is made of a metal material (for example, iron-nickel-cobalt alloy). Four sidewalls 13 to 1 of the case 12
A concave portion (representatively, three concave portions 17 to 19 are shown) is formed at a predetermined position of 6 (however, the illustrated position is an example), and ceramic terminals 20 to 22 are mounted in the concave portions 17 to 19, respectively. . In addition, on the inner peripheral side of the seal ring 11,
The same number of notches 23 and 24 as the recesses 17 to 19 (only two of which can be seen in the figure) are formed, and the notches 23 and 24 are respectively formed when the seal ring 11 is attached to the case 12. It is aligned so as to be directly above the recesses 17 to 19. L _{20 to} L ₂₂ schematically represent lead wires drawn out from the respective ceramic terminals 20 to 22.

FIG. 2 shows a recess 1 of a case 12 as a representative.
9 is an enlarged view of 9 and a ceramic terminal 22. FIG. The width La ′ of the end portion 22a of the ceramic terminal 22 facing the outside of the case 12
Similarly, the width Lb 'of the end portion 22b facing the inside is unequal, and in the figure, La'> Lb '. Therefore, when the imaginary lines 25 and 26 are extended along the side surface of the ceramic terminal 22, The virtual lines 25 and 26 of the book are virtual points 27 separated by a predetermined distance.
And the intersection angle is given by θ. That is, the planar shape of the ceramic terminal 22 is tapered with the angle θ. As with the ceramic terminals 22, the recesses 19 of the case 12 also have unequal widths at both ends facing the inside and outside of the case 12, and are tapered at an angle θ.

According to this structure, the ceramic terminal 22 and the recess 19 of the case 12 have a tapered planar shape, so that the relative horizontal positions of the ceramic terminal 22 and the recess 19 can be simply adjusted. You can adjust the clearance between them freely. For example, the ceramic terminal 22
The clearance is increased by pulling out the case 12 to the outside of the case 12, and the clearance is decreased by pushing the case 12 inside.

Therefore, in this embodiment, since the clearance can be adjusted to an appropriate clearance in spite of an error in machining accuracy, the positional accuracy of the ceramic terminal 22 in the width direction can be improved, and the ceramic terminal 22 and the concave portion can be recessed. It is possible to obtain a unique effect that the amount of the brazing material between 19 can be adjusted to an appropriate amount to suppress the thermal stress, the occurrence of cracks can be avoided, and the reliability can be improved.

Although La '>Lb' is set in the present embodiment, La '<Lb' may be set. In short,
It suffices that La ′ and Lb ′ are unequal and have a tapered shape. Incidentally, FIGS. 3 and 4 are views showing a preferable manufacturing process of the ceramic terminal. In FIG. 3, first, a ground portion pattern 32 and an intermediate layer signal line pattern 33 are printed on the upper half green sheet 30 and the lower half green sheet 31 of a ceramic terminal by a known multilayer ceramic manufacturing method. At the same time, holes 34 to 37 having a predetermined size are opened at predetermined positions, and the two green sheets 30 and 31 are bonded to each other to manufacture a laminated green sheet 38. The lower half of the green sheet 31 is entirely metalized. Here, the ground portion pattern 32, the intermediate layer signal line pattern 33, and the hole 3 are provided.
The points 4 to 37 are to be laid out in a direction parallel to the diagonal lines of the green sheets 30 and 31.

Next, as shown in FIG. 4, the laminated green sheet 38 is cut along a cutting line 39 to 42 parallel to each side with a cutting blade or the like to separate the ceramic terminals.
Finally, the cut surface is metallized, fired, and plated to complete a tapered ceramic terminal. The metallization of the cut surface may be performed by post-firing metallizing after firing the separated ceramic terminals once, or by firing before separating the ceramic terminals and after cutting the ceramic terminals with a dicer or the like. ,
Post-firing metallization may be applied.

Second Embodiment FIGS. 5 to 7 are views showing a second embodiment of the metal package according to the present invention. FIG. 5 is an enlarged view of a main part of this embodiment and an external view of a ceramic terminal, which is a view corresponding to FIG. 2 of the first embodiment. In FIG. 5A, reference numeral 50 denotes a bottomed case (hereinafter referred to as “case”), and the case 50 includes a bottom panel 51 and side walls 52 provided upright on the peripheral edge of the bottom panel 51.
It consists of and. A concave portion 53 opening downward is formed at a predetermined position of the side wall 52, and the concave portion 53 has a concave portion 53.
Ceramic terminals 54 are mounted.

Here, the recess 53 and the ceramic terminal 54 of this embodiment are shaped such that the widths of the respective end portions in the height direction are different. For example, the illustrated ceramic terminal 5
4 will be described with reference to FIG.
As shown in (b), the width La ″ of the end portion 54a on the lower side of the drawing.
The width Lc of the end portion 54b on the upper side of the drawing becomes smaller (L
a ″> Lc), that is, the shape is a downward spread, and the recesses 53 are also formed in substantially the same shape.

According to this structure, the ceramic terminals 54 and the recesses 53 have a tapered cross-sectional shape. Therefore, the relative vertical positions of the ceramic terminals 54 and the recesses 53 can be simply adjusted. You can adjust the clearance between them freely. For example, in the example of FIG. 5, when the ceramic terminal 54 is located on the upper side, the clearance becomes smaller, and when it is located on the lower side, the clearance becomes larger.

Therefore, in this embodiment as well, the clearance can be adjusted to an appropriate clearance despite the error in processing accuracy, and the same effect as in the first embodiment can be obtained. In the example of FIG. 5, La ″> Lc, but
It is not limited to this. What is essential is that they are unequal (La ″ ≠ Lc). For example, as shown in FIG. 6, the end 54b on the upper side of the drawing than the width La ″ of the end 54a ′ on the lower side of the drawing of the ceramic terminal 54 ′. The width Lc of 'becomes larger (La "
The shape may be <Lc), that is, the shape may be expanded upward (the concave portions 53 ′ may have substantially the same shape).

According to this structure, since the ceramic terminals 54 'and the concave portions 53' have a tapered shape in cross section, if the ceramic terminals 54 'are positioned on the upper side, the clearance becomes large, and conversely. If it is located on the lower side, the clearance will be smaller. In addition, in the example of FIG. 6 (in the case of the upward spread shape), the ceramic terminal 54 ′ is connected to the side wall 52 ′.
It is necessary to mount it from above, as shown in FIG. 6, by opening the concave portion 53 ′ upward, and dividing the side wall 52 ′ into two along the line 55.

FIG. 7 is a view showing a preferable manufacturing process of the ceramic terminal 54 of this embodiment. In FIG. 7, reference numeral 56 is a rotary disk-shaped cutting blade, and the cutting edge 56 has a tapered cross section as shown in the drawing. When the laminated green sheet 57 is cut using such a cutting blade 56 having a tapered cross section, the cut surface has an inclination along the cutting edge cross section of the cutting blade 56. Therefore, the ceramic terminal 54 having a desired tapered cross section can be obtained by simply cutting with the cutting blade 56 having the blade angle adjusted to a desired value.
Can be easily manufactured.

In the first and second embodiments, the ceramic terminals are tapered in the horizontal and vertical directions, respectively. However, the combined shape, that is, both the horizontal and vertical directions are tapered. It may be formed into a shape.

[0021]

According to the present invention, the clearance between the ceramic terminal and the recess can be freely adjusted by merely adjusting the relative horizontal position (or vertical position) of the recess.
It is possible to provide a metal package that improves the positional accuracy of the ceramic terminals in the horizontal direction (or the vertical direction), prevents cracks and the like from occurring, and improves reliability.

[Brief description of drawings]

FIG. 1 is an overall external view including a cap according to a first embodiment.

FIG. 2 is an enlarged view of an essential part of the first embodiment and an external view of a ceramic terminal.

FIG. 3 is a manufacturing process diagram (1) of the ceramic terminal of the first embodiment.

FIG. 4 is a manufacturing process diagram (2) of the ceramic terminal of the first embodiment.

FIG. 5 is an enlarged view of a main part of the second embodiment and an external view of a ceramic terminal.

FIG. 6 is an enlarged view of a main part of the second embodiment and an external view of a ceramic terminal.

FIG. 7 is a manufacturing process drawing of the ceramic terminal of the second embodiment.

FIG. 8 is an overall external view, a main part enlarged view, and a ceramic terminal external view of a conventional example.

[Explanation of symbols]

12, 50: Cases 13 to 16, 52, 52 ': Side walls 17 to 19, 53, 53': Recesses 20 to 22, 54, 54 ': Ceramic terminals 22a, 22b, 54a, 54b, 54a', 54
b ': end portions La', Lb ', La ", Lc: width

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographical flat 4-80101 (JP, U) practically open 63-112345 (JP, U) practically flat 2-88242 (JP, U) actual open Sho-63- 115228 (JP, U) Actual development 4-12653 (JP, U) Actual development Sho 63-115227 (JP, U) Actual development Sho 63-115226 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 23/00-23/10 H01L 23/28-23/30 H01L 21/56 H05K 5/04

Claims (4)

(57) [Claims] 1. A side wall (13) of a bottomed case (12) made of metal .
To 16) are provided with recesses (17 to 19), and the ceramic terminals (20 to 22) are provided in the recesses (17 to 19).
In the metal package in which the ceramic terminal is fitted and brazed and fixed, the ceramic terminal has the ground pattern (32) and
And / or signal line patterns (33) are formed, and the recesses (17 to 19) and the ceramic terminals (20 to 2) are formed.
A metal package characterized in that the widths (La ', Lb') of the respective end portions (22a, 22b) facing the inside and outside of the bottomed case (12) of 2) are different. 2. A method according to claim 1, characterized in that with different widths of each end in the height direction of the recess and the ceramic terminal
The described metal package. Wherein the side wall of the metallic bottomed case (50) (5
2, 52 ') are formed with recesses (53, 53'), and the ceramic terminals (54, 5 ') are formed in the recesses (53, 53').
4 ') is fitted and brazed and fixed, in which the recesses (53, 53') and the conductive pattern are formed.
The width (La ", of each end (54a, 54b, 54a ', 54b') in the height direction of the ceramic terminal (54, 54 ')
A metal package characterized by different Lc). Wherein said recess and metal packaging according to claim 3, characterized in that with different widths of each end facing the inside and outside of the bottomed casing of the ceramic pin.